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Marine biotechnology for food
CHAPTER
Marine biotechnology for food
12
Imelda Joseph and Asha Augustine ICAR-Central Marine Fisheries Research Institute, Kochi, India
12.1 Introduction Developed as well as developing countries are facing challenges in sustainable supply of nutritious food and energy, climate change and environmental degradation, health and aging populations. Marine biotechnology can make an increasingly important contribution toward meeting these societal challenges. It can substantially contribute to the growing demand for high quality and healthy food and other products from fisheries and mariculture in a sustainable way. The growing demand for seafood will have to be delivered through improved and innovative culture systems and practices. Efficient and environmentally responsible mariculture and a greater diversity of marine food products are available now due to the biological and biotechnological progress in the past few decades. Biotechnology has paved the way for increasing production efficiency and product quality, introduction of new species for farming; and the development of sustainable practices through a better understanding of the molecular and physiological basis of health, reproduction, development and growth, and a better control of these processes in mariculture. Challenges in understanding and controlling reproduction, early lifestage development, growth, nutrition, daisease and animal health management, environmental interactions, and sustainability are the challenges faced by mariculture. It needs a focused approach to tackle the issues in the coming years. The marine ecosystem represents a largely untapped reservoir of bioactive ingredients that can be applied to numerous aspects of food processing, storage, and fortification. Due to the wide range of environments they survive in, marine organisms have developed unique properties and bioactive compounds that, in some cases, are unparalleled by their terrestrial counterparts. Enzymes extracted from marine organisms provide numerous advantages over traditional enzymes used in food processing due to their ability to function at extremes of pH and temperature. Polysaccharides derived from algae like algins, carrageenans, and agar are widely used as thickeners and stabilizers in foods as well as for gels (Rasmussen and Morrissey, 2007). Fish proteins like collagens and gelatin derivatives could operate at low temperatures and can be used in heat-sensitive processes such as gelling and clarifying (Kim, 2015). Polysaccharides from algae Genomics and Biotechnological Advances in Veterinary, Poultry, and Fisheries. DOI: https://doi.org/10.1016/B978-0-12-816352-8.00012-6 © 2020 Elsevier Inc. All rights reserved.
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like algin, carrageenan, and agar are widely used in a variety of food products. Besides applications in food processing, marine-derived compounds such as omega-3 polyunsaturated fatty acids and pigments, find applications in the nutraceutical industry. These bioactive ingredients provide health benefits, including reduction of heart diseases, diabetes, anticarcinogenic and antiinflammatory activities. Despite the vast possibilities for the use of marine organisms in the food industry, tools of biotechnology are required for successful cultivation and isolation of these bioactive compounds. Marine biotechnology could exploit the enormous potential of the majority of unexplored functional diversity of marine life. It includes new genes, new molecules, and unusual microorganisms and their biochemical processes for the benefit of different sectors like food, industry, medicine, energy, etc. The contribution of the marine environment to the world’s food supply is very significant and according to the Food and Agricultural Organization (FAO), fisheries and aquaculture provide almost 50% of the animal protein supply. Today, consumers often demand minimally processed food, without the addition of chemical preservatives. The application of marine biotechnology could contribute to address the global challenges of food, energy, security, and health as well as contribute to green growth, sustainable industries, etc., leading to a considerable contribution to the economic growth of the country. Biotechnology along with conventional biomass technologies play a major role in converting the huge aquatic biomass into value-added chemicals applying biorefinery concepts. Unlike terrestrial environments, the seas offer a broader variety of useful constituents to be used in foods. There has been a growing interest in functional food ingredients, nutraceuticals, probiotics, prebiotics, enzymes, and various dietary supplements resulting from the processing of marine organisms. In this chapter, developments and upcoming areas of research that utilize advances in biotechnology in the production of food ingredients from marine sources are included (Fig. 12.1).
12.2 Food from marine sources 12.2.1 Marine fish Fish occupy the highest position in marine animal consumption and fish provide approximately 16% of the world’s protein requirements with herring, salmon, cod, flounder, tuna, mullet, and anchovy being the most common species of fish used for food. One of the largest commercially canned fishery products in the world is tuna (e.g., Thunnus obesus). According to the FAO of the United Nations (2018), the total catch of the commercial tuna species increased from 162,980 metric tons in 1950 to more than 5 million metric tons in 2016. The nutritional benefits of fish consumption are due to the presence of proteins, unsaturated
12.2 Food from marine sources
Marine resources Products Culture
• Food • Food supplements • Nutraceuticals • Carotenoids • Vitamins • Minerals • Enzymes
Biotechnology tools/protocols • Mariculture: Breeding–seed production– farming • Genetics-Molecular biology–selection– mariculture • Health management-Vaccines: Probiotics • Environment management—Ecosystem based farming for sustainability • Bioprospecting: food–nutraceuticals
FIGURE 12.1 Marine biotechnology for food.
essential fatty acids, minerals (e.g., calcium, iron, selenium, and zinc), and vitamins (vitamin A, B3, B6, B12, E, and D).
12.2.2 Molluscs, echinoderms, and crustaceans Molluscs, together with echinoderms, have been widely consumed as marine foods and are considered natural functional foods. Many Asian populations consume cuttlefish, squid, octopus, and nautiloids due to their therapeutic effects, for example, rickets are cured with the bones of cuttlefish, as well as gastrointestinal disorders and ear inflammation. Crustaceans are the biggest and most economically important class of marine arthropods in the global fisheries markets; they also have significant roles in nutraceutical industries. Crabs, prawns, and shrimp have gained great attention due to their effective utilization and health benefits. Nutrient composition of marine crustaceans like shrimp and krill was analyzed and found to decrease the total blood lipids in humans, and improve vitamin A levels, specific proteins, and eicosapentaenoic acid, an omega-3 fatty acids. These are suggested to be used in the development of value-added health food products and for human consumption due to high nutritional value (Suleria et al., 2015).
12.2.3 Marine algae Algae include microscopic and macroscopic plants in the marine environment. Seaweeds or marine macrophytes are classified based on various properties such
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as pigmentation, chemical nature of photosynthetic storage product, the organization of photosynthetic membranes, and other morphological features. Seaweeds belong to four different groups, distinguished on the basis of color: blue-green algae (phylum: Cyanophyta, up to 1500 species), red algae (phylum: Rhodophyta, about 6000 species), brown algae (phylum: Ochrophyta, classes: Phaeophyceae, about 1750 species), and green algae (phylum: Chlorophyta, classes: Bryopsidophyceae, Chlorophyceae, Dasycladophyceae, Prasinophyceae, and Ulvophyceae, about 1200 species). Each of these groups also has microscopic representatives. Seaweeds as well as microalgae are crucial primary producers in oceanic aquatic food webs. Seaweeds are rich in minerals and essential trace elements, and raw materials for the pharmaceutical and cosmetics industry (Chapman, 1970). Seaweed is a very versatile product widely used for food in direct human consumption.
12.3 Mariculture technologies for food Mariculture involves farming of marine plants or animals for food, medicine, or any industrial applications. Mariculture is the fastest growing food sector in the world. Global aquaculture production (including aquatic plants) in 2016 was 110.2 million tons, with the first-sale value estimated at USD 243.5 billion. Farmed food fish production included 54.1 million tons of finfish (USD 138.5 billion), 17.1 million tons of molluscs (USD 29.2 billion), 7.9 million tons of crustaceans (USD 57.1 billion), and 938,500 tons of other aquatic animals (USD 6.8 billion) such as turtles, sea cucumbers, sea urchins, frogs, and edible jellyfish. Farmed aquatic plants included mostly seaweeds and a much smaller production volume of microalgae. The nonfood products included only ornamental shells and pearls. Mariculture started by catching wild juveniles and feeding them in a controlled environment. As more knowledge was gained, the degree of control with the production process increased and the farmers increased their influence on growth and reproduction. The degree of control is often categorized by the intensity of the farming operation. Traditional, extensive, semiintensive, and intensive are the existing farming practices (Quentin et al., 2010). Mussel farming is an example of an extensive method of mariculture used around the globe, whereby the farmer provides a rope or a stake for the juveniles to attach to and undertakes some culling so that the density does not get too high, but otherwise leaves the mussels to grow without further interference.
• Marine ponds: Mainly grow prawns and some finfishes either by tide-fed systems or by pumping in seawater at periodic intervals.
• Tanks (broodstock tanks; larval rearing, intensive culture tanks): Some species grow well in well-aerated tanks with regular exchange of water to keep the dissolved oxygen levels high and remove wastes.
12.4 Biotechnology in mariculture
• Sea cage farming (salmon, breams, snapper, seabass, grouper): High density, • • • •
•
low volume system with maximum production in unit area than in any other culture systems. Long line farming of bivalves is a nonfed culture system. Raceway farming: Usually large concrete tanks having higher flow rates than ponds are raceways which are used for farming of many fish species. Hatcheries: Hatcheries are land-based seed production units set up in a protected environment. Integrated multitrophic aquaculture (IMTA) and polyculture: Polyculture and integrated aquaculture are methods of raising diverse organisms within the same farming system, where each species utilizes a distinct niche and distinct resources within the farming complex. Recirculating aquaculture systems (RAS): RAS are closed and low discharge systems which have concerns for water conservation and reduced waste discharges.
12.4 Biotechnology in mariculture 12.4.1 Genetic manipulation The scope for genetic manipulation is greater in fish and bivalves than in domesticated livestock, which are considerably improved by a long history of artificial selection. Because of the higher market value, genetic advances in aquaculture are much ahead for fish than for any other farmed species. Genetic markers play an important role in the construction of high-resolution genetic linkage maps for aquaculture species, in identifying genes involved in quantitative trait loci for marker-assisted selection and in the assessment of implementation of genetic manipulations such as polyploidy and gynogenesis.
12.4.1.1 Selective breeding Since marine organisms are largely wild and relatively little is known about their genetic constitution, genetic improvement studies have wider implications in mariculture than in allied sectors including agriculture. The application of genetics to the breeding and management of cultivable marine organisms result in considerable improvement as in the case of poultry and livestock. In fish breeding studies, both the traditional selective breeding strategies of established animals breeders, and the more novel schemes of gynogenesis, self-fertilization, sex manipulation, and induced polyploidy may be feasible. The appropriate genetic studies can be considered as encompassing those prior to farming, on-farming, and postfarming activities. Genetic studies are important in fisheries for the conservation of genetic resources. The application of genetics to the breeding and management of cultivable marine organisms can very well result in considerable improvement in their farming qualities (Wilkins, 1981).
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12.4.1.2 Polyploidy In addition to transgenic research, advances in chromosome manipulation (polyploidy) also show potential for improving production in the aquaculture industry, particularly in the case of shellfish. Use of polyploidy in aquaculture can result in sterility, along with enhanced growth and survival rates and increased quality of final products. Polyploidy has been experimented in edible oysters in many countries including India.
12.4.1.3 Transgenics Transgenics are organisms into which transgene has been artificially introduced and the transgene stably integrated into their genomes. Transfer of transgene into the nucleus of a target cell where integration into the host genome takes place. The development of transgenic fish can serve as excellent experimental models for basic scientific investigations, environmental toxicology, and in biotechnological applications. The first transgenic fish were produced in and as of 2003, more than 35 species had been genetically engineered in research laboratories worldwide (Wakchaure et al., 2015). Transgenic fish show better gross food conversion regarding the increase in fish weight per unit of food fed rather than their unmodified relatives. The creation of transgenic fish and shellfish is a topic of great interest in aquaculture research due to the potential improvements in production that this technology can offer (Zbikowska, 2003; Dunham, 2010). Major areas of transgenic research in fish include use of growth hormones (GHs) to increase growth and feed conversion efficiency; use of antifreeze proteins for enhanced cold tolerance and freeze resistance; use of antimicrobial peptides for increased disease resistance; use of metabolic genes to promote low-cost, land-based diets; and genetic methods for inducing sterility. Research with transgenic GHs has made the most progress, with the patented production of a line of Atlantic salmon capable of increased growth and feed conversion efficiency. This product has been licensed to a major biotechnology company and is currently awaiting regulatory approval for commercial use in the United States and in Canada. Despite the potential for GMOs in aquaculture, a number of environmental and human health concerns remain. Major concerns include escapement of transgenic fish into the wild, where they could disrupt natural gene pools through breeding with wild species, and the possible detrimental effects of introducing transgenics into the human and aquatic food chains (Dona and Arvanitoyannis, 2009). One way to alleviate fears of escapement and breeding with natural populations has been the creation of sterile organisms. Recent work using the gene excision method has shown a potential way to produce sterile transgenic organisms by crossing two specific lines of transgenic parents. A more traditional method for inducing sterility has been the creation of triploid organisms through chromosome manipulation. Although fish have not responded very well to this technology, it has been very advantageous in the shellfish industry. Because of their sterility, triploid shellfish also have increased growth and flesh
12.4 Biotechnology in mariculture
palatability. The success of these products will ultimately be determined by consumers and their perspectives on the advantages (such as price and availability) of aquatic GMOs versus environmental and human health concerns.
12.4.2 Health management In the past, fish health research has been limited primarily to understanding diseases in aquaculture facilities, where abnormal conditions could be relatively easily observed, treated, and prevented. Disease impacts to wild marine populations are difficult to observe because sick fish are often consumed by predators before they die directly from disease. Alternatively, fish that die directly from disease are often difficult to locate if their bodies sink to the bottom or if mortalities occur at offshore areas. The problem is further increased by the unavailability of marine test fishes with a known disease history that can be used as experimental animals. By rearing colonies of specific pathogen-free test animals, this uncertainty was overcome. These fishes are also useful in developing predictive tools that forecast and prevent diseases in wild populations. The research approach involves a combination of field-based disease observations, followed by hypothesis derivation and testing using SPF fish. Fish health management is a critical component to disease control and is invaluable to improved harvests and sustainable production. Efficient health management tools, such as disease surveillance, farm biosecurity protocols, vaccination regimes, use of immunostimulants, and other tools are helpful in mitigating most losses due to diseases. Vaccination has been proven to be a very effective way of protecting fish from viral and bacterial diseases. Viral vaccines with improved techniques for delivery at affordable prices have been developed in finfish. The majority of the commercial vaccines are targeted at the high-value salmonid industry with vaccines against diseases such as IPN, ISA, IHN, and pancreatic disease (Dhar et al., 2014). The first vaccines were based on inactivated (by heat or chemical) viruses. Inactivated virus vaccines are still a major portion of the overall vaccine supply. The Alpha Jects Micro 1 ISA (Novartis) and Alpha Jects 1000 vaccines are examples of this type of vaccine, targeting ISA and IPN, respectively. However, the use of inactivated viruses as a vaccine is hampered since some fish viruses are not easily culturable, such as SalHV3, a herpesvirus of Atlantic cod and lymphocystis virus, making the production of vaccines for these viruses based on whole inactivated virus difficult. With these and developments in improved and powerful scientific tools, new variations in the types of vaccines available are playing an increasingly important role in fish health management. Ideally, vaccines will allow the differentiation of a vaccinated fish from an infected (or previously infected) fish to aid in epidemiology and disease surveillance/control. These attributes of the ideal vaccine are most likely to be met either by a recombinant subunit vaccine or by an inactivated viral vaccine, as a live attenuated vaccine could potentially lead to carrier formation. Attenuated virus vaccines based on live
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viruses have been selected for cross reactivity (a less virulent virus that elicits an immune response to the target virus), genetically modified to attenuate the virus, and/or cultivated under conditions that disable viral virulence. Subunit vaccines are another class of vaccines that have emerged with the advent of molecular biology. Highly successful examples of subunit vaccines are the IPNV VP2-based vaccine from Microtek International and the ISAV recombinant hemagglutinin esterase gene from Centrovet. Recombinant DNA vaccines involve injecting an organism with histone-free (“naked”) DNA representing a gene of the pathogen itself. A DNA vaccine against IHNV was the first effective DNA vaccine tested in fish. Subsequently, DNA vaccines were tested against a number of fish viruses, including IPNV, VNNV, and SVCV. So far only one DNA vaccine, a vaccine against IHN, has been approved for use in Canada and this vaccine is not approved in Europe and the United States for commercial application due to safety concerns (Dhar et al., 2014).
12.4.3 Environment management This involves ecosystem-based farming for sustainability of aquaculture production system. This is done by rearing several aquatic organisms together. Each species utilizes a distinct niche and distinct resources within the same farming system and optimum utilization of resources with minimum wastage is attained. Several aquatic organisms, which are compatible, are grown together in IMTA and polyculture. Environmental health and sustainability is ensured by such farming complexes. RAS generally consists of land-based tanks with constantly flowing water. RAS conserve water and allow control of all the environmental factors that might affect the stocked organism. RAS has less impact upon environment because, wastes and uneaten feed are not simply released into the ambient environment in the manner that they are with other culture systems and exotic species, and diseases are not introduced into the environment. Another environment management technique is the use of probiotic application for inadequate control of water quality in aquaculture systems.
12.5 Bioprospecting for food 12.5.1 Functional foods and nutraceuticals from marine organisms Marine resources are a source of high-value compounds with nutraceutical value to be used as functional ingredients: omega-3 fatty acids, chitin, chitosan, protein hydrolysates, algal constituents, carotenoids, collagen, taurine, and other bioactive compounds. Nutraceutical refers to raw foods, fortified foods, or dietary supplements containing bioactive molecules that provide health benefits beyond basic nutrition. These bioactive compounds include certain polysaccharides, peptides,
12.5 Bioprospecting for food
phytochemicals, vitamins, and fatty acids that are naturally present in foods, and can be added to foods producing fortified or functional foods or can be formulated into dietary supplements. Macroalgae, also called seaweed, are the most popular type of algae in the nutraceutical industry as it provides a great variety of food and food ingredients especially in Asian countries like Korea, Japan, and China. Agarose is one of the main products from macroalgae. Other metabolites and natural products with unique nutritional and therapeutic properties isolated from seaweeds include proteins, furanone, polyunsaturated fatty acids, L-α kainic acid, phenotics, pigments, phlorotannins, phycocolloids (carrageenan and agar), and minerals. Red and brown seaweeds are alternative sources of vitamins, minerals, and proteins, and are good sources of essential fatty acids. They have been used to prepare bioactive peptides and to improve protein digestibility. Recently, antihypertensive bioactive peptides have been isolated which may act as angiotensin-converting enzyme inhibitors. Macroalgae are also rich sources of insoluble and soluble dietary fiber as they are not digested by enzymes in the gut and are mainly composed of indigestible sulfated polysaccharides. Examples of structural and storage polysaccharides found in red and brown seaweeds include fucan, agar, laminaran, carrageenan, and alginate. The alginates from brown seaweeds are utilized as hydrocolloids due to their biological activity. Food and cosmetic industries use fucans from brown seaweeds. However, all bioactive molecules from algae have not yet been identified and molecules from marine algae may provide different health benefits and biological activities.
12.5.2 Marine sources of bioactive molecules Marine ecosystems have a high diversity of living organisms compared to terrestrial ecosystems providing numerous resources for human nutrition and health. Marine invertebrates are a diverse group with habitats in all ocean ecosystems, ranging from the intertidal zone to the deep sea environment. Marine invertebrates are classified into several phyla, viz., Porifera (sponges), Cnidaria (corals, sea anemones, hydrozoans, jellyfish), Annelida (Polychaetes, marine worms), Bryozoa (moss animals or sea mats), Mollusca (oysters, abalone, clams, mussels, squid, cuttlefish, octopuses), Arthropoda (lobsters, crabs, shrimps, prawns, crayfish), and Echinodermata (sea stars, sea cucumbers, sea urchins). This diverse group also includes seaweeds, microalgae, bacteria, cyanobacteria, certain fish species, and crustaceans that produce secondary metabolites as an adaptation to their hostile marine environment. The global nutraceutical market comprised of functional foods and beverages and dietary supplements, was valued at around USD 250 billion in 2014. Consumer demand for nutraceuticals is rapidly increasing with the market expected to reach around USD 385 billion by 2030 (Suleria et al., 2015). Marine organisms such as sponges, tunicates, bryozoans, molluscs, bacteria, microalgae, macroalgae, and cyanobacteria have recently been utilized for biotechnology. Compounds produced from these organisms are effective as
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therapeutics for infectious and noninfectious disease, with a high specificity for target molecules, usually an enzyme. In the nutraceutical industry, marine algae are used as sources of food and food ingredients. Microalgae, the most simple and primary organized members of marine plant life, are rich sources of food ingredients, such as β-carotene, vitamins C, A, E, H, B1, B2, B6, and B12, astaxanthin, polysaccharides, and polyunsaturated fatty acids. As such, bioactive molecules from microalgae are commercially produced, used as food additives, and also incorporated into infant milk formulations and dietary supplements. Marine fish contains proteins, unsaturated essential fatty acids, minerals, and vitamins and is highly nutritional. Crustaceans with eicosapentanoic acid also have significant roles in nutraceutical industries. Marine organisms are one of the most important sources of bioactive compounds for the food and pharmaceutical industries. Bioactive compounds can be isolated from various sources including marine plants, animals, and microorganisms. Marine bioactive compounds that have been most extensively studied include carbohydrates, pigments, polyphenols, peptides, proteins, and essential fatty acids. These compounds have rheological properties, deeming them useful in the food industry, as well as various biological functions like antioxidant, antithrombotic, anticoagulant, antiinflammatory, antiproliferative, antihypertensive, antidiabetic, and cardio-protection activities making them attractive nutraceuticals and pharmaceutical compounds. Agar, alginate, and carrageenans are high-value seaweed hydrocolloids, which are used as gelation and thickening agents in different food, pharmaceutical, and biotechnological applications. The annual global production of these hydrocolloids has reached 100,000 tons with a gross market value just above USD 1.1 billion. Seaweed polysaccharides are widely utilized in the food industry and are of particular technological importance due to their broad spectrum of functionality. The physical properties (e.g., gelling, viscosity enhancement, etc.) are tunable by controlling molecular properties of the chains and the environmental conditions (e.g., pH, ionic strength, etc.). This results in hydrocolloid systems with a remarkably wide spectrum of physical properties that find applications across food industry. The most industrially relevant types of carrageenan are kappa-, lambda-, and iotasulfated anionic galactans. Agar is also a linear galactan with backbone of two alternating disaccharides, agarobiose, and seaweed polysaccharides (agar, alginate, carrageenan), and neoagarobiose consisting of two major polysaccharide fractions, namely agarose and agaropectin. Use of seaweed polysaccharides in foods is well established and its potential in or drug industries are also being established.
12.5.3 Bioactive compounds of importance in farming 12.5.3.1 Carotenoids Carotenoid pigments, obtained by animals from their diets, give most of the bright red, yellow, and orange colors well appreciated in aquaculture (Toyomizu
12.5 Bioprospecting for food
et al., 2001). Only plants, bacteria, fungi, and algae can synthesize carotenoids; animals cannot biosynthesize them thus, they must be obtained from the diet (Schiedt, 1998). They play a critical role in the photosynthetic process and they carry out a protective function against damage by light and oxygen. Carotenoids also play other important functions as pro-vitamin A, antioxidants, immunoregulators, and they are mobilized from muscle to ovaries which suggest a function in reproduction (Shahidi et al., 1998; Nakano et al., 1999). It has also observed that fishes with a high level of carotenoids are more resistant to bacterial and fungal diseases (Shahidi et al., 1998). Carotenoids have been included in diets of salmonids, crustaceans, and other farmed fish, mainly as pigments to provide a desirable coloration to the cultured organisms. Carotenoids not only contribute in improving quality by enhancing color, but could also help to give a better image in the minds of consumers of aquaculture products, in view of increasing information available on carotenoids’ positive effect on human health. Aside from their quality enhancing properties, carotenoids seem to improve certain production parameters of farmed species. In crustaceans, such as shrimp, a bright and appropriate color is also associated with freshness and quality and the desired coloration preserved through storage, processing, and cooking (Boonyaratpalin et al., 2001). In the sea urchin industry, based on the production of marketable gonads, the highest commercially valuable sea urchin gonads are bright yellow-orange (Shpigel et al., 2004). Astaxanthin is a high-value keto-carotenoid pigment renowned for its commercial application in various industries comprising aquaculture, food, cosmetic, nutraceutical, and pharmaceutical. Among the verified bioresources of astaxanthin are red yeast Phaffia rhodozyma and green alga Haematococcus pluvialis. The supreme antioxidant property of astaxanthin reveals its tremendous potential to offer manifold health benefits among aquatic animals which is a key driving factor triggering the upsurge in global demand for the pigment. Carotenoids play a significant role in shrimp aquaculture also. Crustaceans cannot synthesize carotenoids, thus it must be supplied in their diet. Astaxanthin is the optimal carotenoid for the proper pigmentation of Penaeiid shrimps. A nutritional deficiency of astaxanthin in the diet causes blue color syndrome. Additional benefits of this essential carotenoid include roles as an antioxidant and precursor of vitamin A, as well as enhancing immune response, reproduction, growth, maturation, photoprotection, and defense against hypoxic conditions in culture ponds. Astaxanthin dramatically improves the nauplii quality and zoea survival of shrimp broodstock. One first strategy would be to supplement shrimp diets with 75 150 ppm of commercial astaxanthin 2 months prior to harvest to achieve a total body carotenoid content in excess of the critical threshold of 30 40 mg/kg. Broodstock supplemented with 150 ppm of astaxanthin has been found to significantly improve nauplii quality and zoea survival (Lorenz, 1998).
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12.6 Conclusion As more food of high nutritional quality are in need for the ever-increasing human population, biotechnology is looked at as the solution for enhanced production as well as improved varieties. Marine biotechnology is untapped compared to plant and other terrestrial animal biotechnology. The future development in mariculture, which would be the major food supplying system in the world, is to develop innovative methods based on molecular biology for selective breeding of mariculture species; develop biotechnological applications and methods to increase sustainability of ecosystem-based aquaculture production, including alternative preventive and therapeutic measures to enhance environmental welfare; sustainable production technologies for feed supply; intensive farming through recirculating farming systems with zero wastes; and integration of new, low environmental impact feed ingredients including alternatives for fishmeal and fish oil.
References Boonyaratpalin, M., Thongrod, S., Supamattaya, K., Britton, G.E., Schlipalius, L., 2001. Effects of β-carotene source, Dunaliella salina, and astaxanthin on pigmentation, growth, survival and health of Penaeus monodon. Aquacult. Res. 32, 182 190. Chapman, V.J., 1970. Seaweeds and Their Uses. Methuen & Co Ltd, London, 304 pp. Dhar, A.K., Manna, S.K., Allnutt, F.C.T., 2014. Viral vaccines for farmed finfish. Virus Disease 25 (1), 1 17. Dona, A.I., Arvanitoyannis, I.S., 2009. Health risks of genetically modified foods. Crit. Rev. Food Sci. Nutr. 49 (2), 164 175. Dunham, R.A., 2010. Aquaculture and Fisheries Biotechnology, Genetic Approaches, second ed. Stylus Cabi Publishing, 495 pp. FAO, 2018. The State of World Fisheries and Aquaculture. FAO, Rome, 227 pp. Kim, S.K., 2015. Handbook of Marine Biotechnology. Springer, Berlin, Heidelberg. Lorenz, R.T., 1998. A review of the carotenoid, astaxanthin, as a pigment source and vitamin for cultured Penaeus prawn. NatuRosea Tech. Bullet. 51, 1 7. Nakano, T., Miura, Y., Wazawa, M., Sato, M., Takeuchi, M., 1999. Red yeast Phaffia rhodozyma reduces susceptibility of liver homogenate to lipid peroxidation in rainbow trout. Fish. Sci. 65, 961 962. Quentin, R.G., Ray, H., Dale, S., Maree, T., Meryl, W., 2010. Handbook of Marine Fisheries Conservation and Management. Oxford University Press, Oxford, New York, 770 pp. Rasmussen, R.S., Morrissey, M.T., 2007. Marine biotechnology for production of food ingredients. In: Taylor, S.L. (Ed.), Advances in Food and Nutrition Research. Elsevier, New York, pp. 237 292. Schiedt, K., 1998. Absorption and metabolism of carotenoids in birds, fish and crustaceans. In: Britton, G., Liaaen-Jensen, S., Pfander, H. (Eds.), Carotenoids Biosynthesis and Metabolism. Birkha¨user, Basel, pp. 285 358.
References
Shahidi, F., Metusalach, J., Brown, J.A., 1998. Carotenoid pigments in seafoods and aquaculture. Crit. Rev. Food Sci. 38, 1 67. Shpigel, M., McBride, S.C., Marciano, S., Lipatch, I., 2004. The effect of photoperiod and temperature on the production of European sea urchin, Paracentrotus lividus. Aquaculture 245, 101 109. Suleria, H.A., Osborne, S., Masci, P., Gobe, G., 2015. Marine-based nutraceuticals: an innovative trend in the food and supplement industries. Mar. Drugs 13, 6336 6351. Toyomizu, M., Sato, K., Taroda, H., Kato, T., Akiba, Y., 2001. Effects of dietary Spirulina on meat color inmuscle of broiler chickens. Br. Poultry Sci. 42, 197 202. Wakchaure, R., Ganguly, S., Qadri, K., Praveen, P.K., Mahajan, T., 2015. Importance of transgenic fish to global aquaculture: a review. Fish. Aquac. J. 6, 124. Wilkins, N.P., 1981. The rationale and relevance of genetics in aquaculture: an overview. Aquaculture 22, 209 228. Zbikowska, H.M., 2003. Fish can be first—advances in fish transgenesis for commercial applications. Transgenic Res. 12 (4), 379 389.
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Imelda Joseph and Asha Augustine ICAR-Central Marine Fisheries Research Institute, Kochi, India
12.1 Introduction Developed as well as developing countries are facing challenges in sustainable supply of nutritious food and energy, climate change and environmental degradation, health and aging populations. Marine biotechnology can make an increasingly important contribution toward meeting these societal challenges. It can substantially contribute to the growing demand for high quality and healthy food and other products from fisheries and mariculture in a sustainable way. The growing demand for seafood will have to be delivered through improved and innovative culture systems and practices. Efficient and environmentally responsible mariculture and a greater diversity of marine food products are available now due to the biological and biotechnological progress in the past few decades. Biotechnology has paved the way for increasing production efficiency and product quality, introduction of new species for farming; and the development of sustainable practices through a better understanding of the molecular and physiological basis of health, reproduction, development and growth, and a better control of these processes in mariculture. Challenges in understanding and controlling reproduction, early lifestage development, growth, nutrition, daisease and animal health management, environmental interactions, and sustainability are the challenges faced by mariculture. It needs a focused approach to tackle the issues in the coming years. The marine ecosystem represents a largely untapped reservoir of bioactive ingredients that can be applied to numerous aspects of food processing, storage, and fortification. Due to the wide range of environments they survive in, marine organisms have developed unique properties and bioactive compounds that, in some cases, are unparalleled by their terrestrial counterparts. Enzymes extracted from marine organisms provide numerous advantages over traditional enzymes used in food processing due to their ability to function at extremes of pH and temperature. Polysaccharides derived from algae like algins, carrageenans, and agar are widely used as thickeners and stabilizers in foods as well as for gels (Rasmussen and Morrissey, 2007). Fish proteins like collagens and gelatin derivatives could operate at low temperatures and can be used in heat-sensitive processes such as gelling and clarifying (Kim, 2015). Polysaccharides from algae Genomics and Biotechnological Advances in Veterinary, Poultry, and Fisheries. DOI: https://doi.org/10.1016/B978-0-12-816352-8.00012-6 © 2020 Elsevier Inc. All rights reserved.
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like algin, carrageenan, and agar are widely used in a variety of food products. Besides applications in food processing, marine-derived compounds such as omega-3 polyunsaturated fatty acids and pigments, find applications in the nutraceutical industry. These bioactive ingredients provide health benefits, including reduction of heart diseases, diabetes, anticarcinogenic and antiinflammatory activities. Despite the vast possibilities for the use of marine organisms in the food industry, tools of biotechnology are required for successful cultivation and isolation of these bioactive compounds. Marine biotechnology could exploit the enormous potential of the majority of unexplored functional diversity of marine life. It includes new genes, new molecules, and unusual microorganisms and their biochemical processes for the benefit of different sectors like food, industry, medicine, energy, etc. The contribution of the marine environment to the world’s food supply is very significant and according to the Food and Agricultural Organization (FAO), fisheries and aquaculture provide almost 50% of the animal protein supply. Today, consumers often demand minimally processed food, without the addition of chemical preservatives. The application of marine biotechnology could contribute to address the global challenges of food, energy, security, and health as well as contribute to green growth, sustainable industries, etc., leading to a considerable contribution to the economic growth of the country. Biotechnology along with conventional biomass technologies play a major role in converting the huge aquatic biomass into value-added chemicals applying biorefinery concepts. Unlike terrestrial environments, the seas offer a broader variety of useful constituents to be used in foods. There has been a growing interest in functional food ingredients, nutraceuticals, probiotics, prebiotics, enzymes, and various dietary supplements resulting from the processing of marine organisms. In this chapter, developments and upcoming areas of research that utilize advances in biotechnology in the production of food ingredients from marine sources are included (Fig. 12.1).
12.2 Food from marine sources 12.2.1 Marine fish Fish occupy the highest position in marine animal consumption and fish provide approximately 16% of the world’s protein requirements with herring, salmon, cod, flounder, tuna, mullet, and anchovy being the most common species of fish used for food. One of the largest commercially canned fishery products in the world is tuna (e.g., Thunnus obesus). According to the FAO of the United Nations (2018), the total catch of the commercial tuna species increased from 162,980 metric tons in 1950 to more than 5 million metric tons in 2016. The nutritional benefits of fish consumption are due to the presence of proteins, unsaturated
12.2 Food from marine sources
Marine resources Products Culture
• Food • Food supplements • Nutraceuticals • Carotenoids • Vitamins • Minerals • Enzymes
Biotechnology tools/protocols • Mariculture: Breeding–seed production– farming • Genetics-Molecular biology–selection– mariculture • Health management-Vaccines: Probiotics • Environment management—Ecosystem based farming for sustainability • Bioprospecting: food–nutraceuticals
FIGURE 12.1 Marine biotechnology for food.
essential fatty acids, minerals (e.g., calcium, iron, selenium, and zinc), and vitamins (vitamin A, B3, B6, B12, E, and D).
12.2.2 Molluscs, echinoderms, and crustaceans Molluscs, together with echinoderms, have been widely consumed as marine foods and are considered natural functional foods. Many Asian populations consume cuttlefish, squid, octopus, and nautiloids due to their therapeutic effects, for example, rickets are cured with the bones of cuttlefish, as well as gastrointestinal disorders and ear inflammation. Crustaceans are the biggest and most economically important class of marine arthropods in the global fisheries markets; they also have significant roles in nutraceutical industries. Crabs, prawns, and shrimp have gained great attention due to their effective utilization and health benefits. Nutrient composition of marine crustaceans like shrimp and krill was analyzed and found to decrease the total blood lipids in humans, and improve vitamin A levels, specific proteins, and eicosapentaenoic acid, an omega-3 fatty acids. These are suggested to be used in the development of value-added health food products and for human consumption due to high nutritional value (Suleria et al., 2015).
12.2.3 Marine algae Algae include microscopic and macroscopic plants in the marine environment. Seaweeds or marine macrophytes are classified based on various properties such
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as pigmentation, chemical nature of photosynthetic storage product, the organization of photosynthetic membranes, and other morphological features. Seaweeds belong to four different groups, distinguished on the basis of color: blue-green algae (phylum: Cyanophyta, up to 1500 species), red algae (phylum: Rhodophyta, about 6000 species), brown algae (phylum: Ochrophyta, classes: Phaeophyceae, about 1750 species), and green algae (phylum: Chlorophyta, classes: Bryopsidophyceae, Chlorophyceae, Dasycladophyceae, Prasinophyceae, and Ulvophyceae, about 1200 species). Each of these groups also has microscopic representatives. Seaweeds as well as microalgae are crucial primary producers in oceanic aquatic food webs. Seaweeds are rich in minerals and essential trace elements, and raw materials for the pharmaceutical and cosmetics industry (Chapman, 1970). Seaweed is a very versatile product widely used for food in direct human consumption.
12.3 Mariculture technologies for food Mariculture involves farming of marine plants or animals for food, medicine, or any industrial applications. Mariculture is the fastest growing food sector in the world. Global aquaculture production (including aquatic plants) in 2016 was 110.2 million tons, with the first-sale value estimated at USD 243.5 billion. Farmed food fish production included 54.1 million tons of finfish (USD 138.5 billion), 17.1 million tons of molluscs (USD 29.2 billion), 7.9 million tons of crustaceans (USD 57.1 billion), and 938,500 tons of other aquatic animals (USD 6.8 billion) such as turtles, sea cucumbers, sea urchins, frogs, and edible jellyfish. Farmed aquatic plants included mostly seaweeds and a much smaller production volume of microalgae. The nonfood products included only ornamental shells and pearls. Mariculture started by catching wild juveniles and feeding them in a controlled environment. As more knowledge was gained, the degree of control with the production process increased and the farmers increased their influence on growth and reproduction. The degree of control is often categorized by the intensity of the farming operation. Traditional, extensive, semiintensive, and intensive are the existing farming practices (Quentin et al., 2010). Mussel farming is an example of an extensive method of mariculture used around the globe, whereby the farmer provides a rope or a stake for the juveniles to attach to and undertakes some culling so that the density does not get too high, but otherwise leaves the mussels to grow without further interference.
• Marine ponds: Mainly grow prawns and some finfishes either by tide-fed systems or by pumping in seawater at periodic intervals.
• Tanks (broodstock tanks; larval rearing, intensive culture tanks): Some species grow well in well-aerated tanks with regular exchange of water to keep the dissolved oxygen levels high and remove wastes.
12.4 Biotechnology in mariculture
• Sea cage farming (salmon, breams, snapper, seabass, grouper): High density, • • • •
•
low volume system with maximum production in unit area than in any other culture systems. Long line farming of bivalves is a nonfed culture system. Raceway farming: Usually large concrete tanks having higher flow rates than ponds are raceways which are used for farming of many fish species. Hatcheries: Hatcheries are land-based seed production units set up in a protected environment. Integrated multitrophic aquaculture (IMTA) and polyculture: Polyculture and integrated aquaculture are methods of raising diverse organisms within the same farming system, where each species utilizes a distinct niche and distinct resources within the farming complex. Recirculating aquaculture systems (RAS): RAS are closed and low discharge systems which have concerns for water conservation and reduced waste discharges.
12.4 Biotechnology in mariculture 12.4.1 Genetic manipulation The scope for genetic manipulation is greater in fish and bivalves than in domesticated livestock, which are considerably improved by a long history of artificial selection. Because of the higher market value, genetic advances in aquaculture are much ahead for fish than for any other farmed species. Genetic markers play an important role in the construction of high-resolution genetic linkage maps for aquaculture species, in identifying genes involved in quantitative trait loci for marker-assisted selection and in the assessment of implementation of genetic manipulations such as polyploidy and gynogenesis.
12.4.1.1 Selective breeding Since marine organisms are largely wild and relatively little is known about their genetic constitution, genetic improvement studies have wider implications in mariculture than in allied sectors including agriculture. The application of genetics to the breeding and management of cultivable marine organisms result in considerable improvement as in the case of poultry and livestock. In fish breeding studies, both the traditional selective breeding strategies of established animals breeders, and the more novel schemes of gynogenesis, self-fertilization, sex manipulation, and induced polyploidy may be feasible. The appropriate genetic studies can be considered as encompassing those prior to farming, on-farming, and postfarming activities. Genetic studies are important in fisheries for the conservation of genetic resources. The application of genetics to the breeding and management of cultivable marine organisms can very well result in considerable improvement in their farming qualities (Wilkins, 1981).
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12.4.1.2 Polyploidy In addition to transgenic research, advances in chromosome manipulation (polyploidy) also show potential for improving production in the aquaculture industry, particularly in the case of shellfish. Use of polyploidy in aquaculture can result in sterility, along with enhanced growth and survival rates and increased quality of final products. Polyploidy has been experimented in edible oysters in many countries including India.
12.4.1.3 Transgenics Transgenics are organisms into which transgene has been artificially introduced and the transgene stably integrated into their genomes. Transfer of transgene into the nucleus of a target cell where integration into the host genome takes place. The development of transgenic fish can serve as excellent experimental models for basic scientific investigations, environmental toxicology, and in biotechnological applications. The first transgenic fish were produced in and as of 2003, more than 35 species had been genetically engineered in research laboratories worldwide (Wakchaure et al., 2015). Transgenic fish show better gross food conversion regarding the increase in fish weight per unit of food fed rather than their unmodified relatives. The creation of transgenic fish and shellfish is a topic of great interest in aquaculture research due to the potential improvements in production that this technology can offer (Zbikowska, 2003; Dunham, 2010). Major areas of transgenic research in fish include use of growth hormones (GHs) to increase growth and feed conversion efficiency; use of antifreeze proteins for enhanced cold tolerance and freeze resistance; use of antimicrobial peptides for increased disease resistance; use of metabolic genes to promote low-cost, land-based diets; and genetic methods for inducing sterility. Research with transgenic GHs has made the most progress, with the patented production of a line of Atlantic salmon capable of increased growth and feed conversion efficiency. This product has been licensed to a major biotechnology company and is currently awaiting regulatory approval for commercial use in the United States and in Canada. Despite the potential for GMOs in aquaculture, a number of environmental and human health concerns remain. Major concerns include escapement of transgenic fish into the wild, where they could disrupt natural gene pools through breeding with wild species, and the possible detrimental effects of introducing transgenics into the human and aquatic food chains (Dona and Arvanitoyannis, 2009). One way to alleviate fears of escapement and breeding with natural populations has been the creation of sterile organisms. Recent work using the gene excision method has shown a potential way to produce sterile transgenic organisms by crossing two specific lines of transgenic parents. A more traditional method for inducing sterility has been the creation of triploid organisms through chromosome manipulation. Although fish have not responded very well to this technology, it has been very advantageous in the shellfish industry. Because of their sterility, triploid shellfish also have increased growth and flesh
12.4 Biotechnology in mariculture
palatability. The success of these products will ultimately be determined by consumers and their perspectives on the advantages (such as price and availability) of aquatic GMOs versus environmental and human health concerns.
12.4.2 Health management In the past, fish health research has been limited primarily to understanding diseases in aquaculture facilities, where abnormal conditions could be relatively easily observed, treated, and prevented. Disease impacts to wild marine populations are difficult to observe because sick fish are often consumed by predators before they die directly from disease. Alternatively, fish that die directly from disease are often difficult to locate if their bodies sink to the bottom or if mortalities occur at offshore areas. The problem is further increased by the unavailability of marine test fishes with a known disease history that can be used as experimental animals. By rearing colonies of specific pathogen-free test animals, this uncertainty was overcome. These fishes are also useful in developing predictive tools that forecast and prevent diseases in wild populations. The research approach involves a combination of field-based disease observations, followed by hypothesis derivation and testing using SPF fish. Fish health management is a critical component to disease control and is invaluable to improved harvests and sustainable production. Efficient health management tools, such as disease surveillance, farm biosecurity protocols, vaccination regimes, use of immunostimulants, and other tools are helpful in mitigating most losses due to diseases. Vaccination has been proven to be a very effective way of protecting fish from viral and bacterial diseases. Viral vaccines with improved techniques for delivery at affordable prices have been developed in finfish. The majority of the commercial vaccines are targeted at the high-value salmonid industry with vaccines against diseases such as IPN, ISA, IHN, and pancreatic disease (Dhar et al., 2014). The first vaccines were based on inactivated (by heat or chemical) viruses. Inactivated virus vaccines are still a major portion of the overall vaccine supply. The Alpha Jects Micro 1 ISA (Novartis) and Alpha Jects 1000 vaccines are examples of this type of vaccine, targeting ISA and IPN, respectively. However, the use of inactivated viruses as a vaccine is hampered since some fish viruses are not easily culturable, such as SalHV3, a herpesvirus of Atlantic cod and lymphocystis virus, making the production of vaccines for these viruses based on whole inactivated virus difficult. With these and developments in improved and powerful scientific tools, new variations in the types of vaccines available are playing an increasingly important role in fish health management. Ideally, vaccines will allow the differentiation of a vaccinated fish from an infected (or previously infected) fish to aid in epidemiology and disease surveillance/control. These attributes of the ideal vaccine are most likely to be met either by a recombinant subunit vaccine or by an inactivated viral vaccine, as a live attenuated vaccine could potentially lead to carrier formation. Attenuated virus vaccines based on live
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viruses have been selected for cross reactivity (a less virulent virus that elicits an immune response to the target virus), genetically modified to attenuate the virus, and/or cultivated under conditions that disable viral virulence. Subunit vaccines are another class of vaccines that have emerged with the advent of molecular biology. Highly successful examples of subunit vaccines are the IPNV VP2-based vaccine from Microtek International and the ISAV recombinant hemagglutinin esterase gene from Centrovet. Recombinant DNA vaccines involve injecting an organism with histone-free (“naked”) DNA representing a gene of the pathogen itself. A DNA vaccine against IHNV was the first effective DNA vaccine tested in fish. Subsequently, DNA vaccines were tested against a number of fish viruses, including IPNV, VNNV, and SVCV. So far only one DNA vaccine, a vaccine against IHN, has been approved for use in Canada and this vaccine is not approved in Europe and the United States for commercial application due to safety concerns (Dhar et al., 2014).
12.4.3 Environment management This involves ecosystem-based farming for sustainability of aquaculture production system. This is done by rearing several aquatic organisms together. Each species utilizes a distinct niche and distinct resources within the same farming system and optimum utilization of resources with minimum wastage is attained. Several aquatic organisms, which are compatible, are grown together in IMTA and polyculture. Environmental health and sustainability is ensured by such farming complexes. RAS generally consists of land-based tanks with constantly flowing water. RAS conserve water and allow control of all the environmental factors that might affect the stocked organism. RAS has less impact upon environment because, wastes and uneaten feed are not simply released into the ambient environment in the manner that they are with other culture systems and exotic species, and diseases are not introduced into the environment. Another environment management technique is the use of probiotic application for inadequate control of water quality in aquaculture systems.
12.5 Bioprospecting for food 12.5.1 Functional foods and nutraceuticals from marine organisms Marine resources are a source of high-value compounds with nutraceutical value to be used as functional ingredients: omega-3 fatty acids, chitin, chitosan, protein hydrolysates, algal constituents, carotenoids, collagen, taurine, and other bioactive compounds. Nutraceutical refers to raw foods, fortified foods, or dietary supplements containing bioactive molecules that provide health benefits beyond basic nutrition. These bioactive compounds include certain polysaccharides, peptides,
12.5 Bioprospecting for food
phytochemicals, vitamins, and fatty acids that are naturally present in foods, and can be added to foods producing fortified or functional foods or can be formulated into dietary supplements. Macroalgae, also called seaweed, are the most popular type of algae in the nutraceutical industry as it provides a great variety of food and food ingredients especially in Asian countries like Korea, Japan, and China. Agarose is one of the main products from macroalgae. Other metabolites and natural products with unique nutritional and therapeutic properties isolated from seaweeds include proteins, furanone, polyunsaturated fatty acids, L-α kainic acid, phenotics, pigments, phlorotannins, phycocolloids (carrageenan and agar), and minerals. Red and brown seaweeds are alternative sources of vitamins, minerals, and proteins, and are good sources of essential fatty acids. They have been used to prepare bioactive peptides and to improve protein digestibility. Recently, antihypertensive bioactive peptides have been isolated which may act as angiotensin-converting enzyme inhibitors. Macroalgae are also rich sources of insoluble and soluble dietary fiber as they are not digested by enzymes in the gut and are mainly composed of indigestible sulfated polysaccharides. Examples of structural and storage polysaccharides found in red and brown seaweeds include fucan, agar, laminaran, carrageenan, and alginate. The alginates from brown seaweeds are utilized as hydrocolloids due to their biological activity. Food and cosmetic industries use fucans from brown seaweeds. However, all bioactive molecules from algae have not yet been identified and molecules from marine algae may provide different health benefits and biological activities.
12.5.2 Marine sources of bioactive molecules Marine ecosystems have a high diversity of living organisms compared to terrestrial ecosystems providing numerous resources for human nutrition and health. Marine invertebrates are a diverse group with habitats in all ocean ecosystems, ranging from the intertidal zone to the deep sea environment. Marine invertebrates are classified into several phyla, viz., Porifera (sponges), Cnidaria (corals, sea anemones, hydrozoans, jellyfish), Annelida (Polychaetes, marine worms), Bryozoa (moss animals or sea mats), Mollusca (oysters, abalone, clams, mussels, squid, cuttlefish, octopuses), Arthropoda (lobsters, crabs, shrimps, prawns, crayfish), and Echinodermata (sea stars, sea cucumbers, sea urchins). This diverse group also includes seaweeds, microalgae, bacteria, cyanobacteria, certain fish species, and crustaceans that produce secondary metabolites as an adaptation to their hostile marine environment. The global nutraceutical market comprised of functional foods and beverages and dietary supplements, was valued at around USD 250 billion in 2014. Consumer demand for nutraceuticals is rapidly increasing with the market expected to reach around USD 385 billion by 2030 (Suleria et al., 2015). Marine organisms such as sponges, tunicates, bryozoans, molluscs, bacteria, microalgae, macroalgae, and cyanobacteria have recently been utilized for biotechnology. Compounds produced from these organisms are effective as
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therapeutics for infectious and noninfectious disease, with a high specificity for target molecules, usually an enzyme. In the nutraceutical industry, marine algae are used as sources of food and food ingredients. Microalgae, the most simple and primary organized members of marine plant life, are rich sources of food ingredients, such as β-carotene, vitamins C, A, E, H, B1, B2, B6, and B12, astaxanthin, polysaccharides, and polyunsaturated fatty acids. As such, bioactive molecules from microalgae are commercially produced, used as food additives, and also incorporated into infant milk formulations and dietary supplements. Marine fish contains proteins, unsaturated essential fatty acids, minerals, and vitamins and is highly nutritional. Crustaceans with eicosapentanoic acid also have significant roles in nutraceutical industries. Marine organisms are one of the most important sources of bioactive compounds for the food and pharmaceutical industries. Bioactive compounds can be isolated from various sources including marine plants, animals, and microorganisms. Marine bioactive compounds that have been most extensively studied include carbohydrates, pigments, polyphenols, peptides, proteins, and essential fatty acids. These compounds have rheological properties, deeming them useful in the food industry, as well as various biological functions like antioxidant, antithrombotic, anticoagulant, antiinflammatory, antiproliferative, antihypertensive, antidiabetic, and cardio-protection activities making them attractive nutraceuticals and pharmaceutical compounds. Agar, alginate, and carrageenans are high-value seaweed hydrocolloids, which are used as gelation and thickening agents in different food, pharmaceutical, and biotechnological applications. The annual global production of these hydrocolloids has reached 100,000 tons with a gross market value just above USD 1.1 billion. Seaweed polysaccharides are widely utilized in the food industry and are of particular technological importance due to their broad spectrum of functionality. The physical properties (e.g., gelling, viscosity enhancement, etc.) are tunable by controlling molecular properties of the chains and the environmental conditions (e.g., pH, ionic strength, etc.). This results in hydrocolloid systems with a remarkably wide spectrum of physical properties that find applications across food industry. The most industrially relevant types of carrageenan are kappa-, lambda-, and iotasulfated anionic galactans. Agar is also a linear galactan with backbone of two alternating disaccharides, agarobiose, and seaweed polysaccharides (agar, alginate, carrageenan), and neoagarobiose consisting of two major polysaccharide fractions, namely agarose and agaropectin. Use of seaweed polysaccharides in foods is well established and its potential in or drug industries are also being established.
12.5.3 Bioactive compounds of importance in farming 12.5.3.1 Carotenoids Carotenoid pigments, obtained by animals from their diets, give most of the bright red, yellow, and orange colors well appreciated in aquaculture (Toyomizu
12.5 Bioprospecting for food
et al., 2001). Only plants, bacteria, fungi, and algae can synthesize carotenoids; animals cannot biosynthesize them thus, they must be obtained from the diet (Schiedt, 1998). They play a critical role in the photosynthetic process and they carry out a protective function against damage by light and oxygen. Carotenoids also play other important functions as pro-vitamin A, antioxidants, immunoregulators, and they are mobilized from muscle to ovaries which suggest a function in reproduction (Shahidi et al., 1998; Nakano et al., 1999). It has also observed that fishes with a high level of carotenoids are more resistant to bacterial and fungal diseases (Shahidi et al., 1998). Carotenoids have been included in diets of salmonids, crustaceans, and other farmed fish, mainly as pigments to provide a desirable coloration to the cultured organisms. Carotenoids not only contribute in improving quality by enhancing color, but could also help to give a better image in the minds of consumers of aquaculture products, in view of increasing information available on carotenoids’ positive effect on human health. Aside from their quality enhancing properties, carotenoids seem to improve certain production parameters of farmed species. In crustaceans, such as shrimp, a bright and appropriate color is also associated with freshness and quality and the desired coloration preserved through storage, processing, and cooking (Boonyaratpalin et al., 2001). In the sea urchin industry, based on the production of marketable gonads, the highest commercially valuable sea urchin gonads are bright yellow-orange (Shpigel et al., 2004). Astaxanthin is a high-value keto-carotenoid pigment renowned for its commercial application in various industries comprising aquaculture, food, cosmetic, nutraceutical, and pharmaceutical. Among the verified bioresources of astaxanthin are red yeast Phaffia rhodozyma and green alga Haematococcus pluvialis. The supreme antioxidant property of astaxanthin reveals its tremendous potential to offer manifold health benefits among aquatic animals which is a key driving factor triggering the upsurge in global demand for the pigment. Carotenoids play a significant role in shrimp aquaculture also. Crustaceans cannot synthesize carotenoids, thus it must be supplied in their diet. Astaxanthin is the optimal carotenoid for the proper pigmentation of Penaeiid shrimps. A nutritional deficiency of astaxanthin in the diet causes blue color syndrome. Additional benefits of this essential carotenoid include roles as an antioxidant and precursor of vitamin A, as well as enhancing immune response, reproduction, growth, maturation, photoprotection, and defense against hypoxic conditions in culture ponds. Astaxanthin dramatically improves the nauplii quality and zoea survival of shrimp broodstock. One first strategy would be to supplement shrimp diets with 75 150 ppm of commercial astaxanthin 2 months prior to harvest to achieve a total body carotenoid content in excess of the critical threshold of 30 40 mg/kg. Broodstock supplemented with 150 ppm of astaxanthin has been found to significantly improve nauplii quality and zoea survival (Lorenz, 1998).
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12.6 Conclusion As more food of high nutritional quality are in need for the ever-increasing human population, biotechnology is looked at as the solution for enhanced production as well as improved varieties. Marine biotechnology is untapped compared to plant and other terrestrial animal biotechnology. The future development in mariculture, which would be the major food supplying system in the world, is to develop innovative methods based on molecular biology for selective breeding of mariculture species; develop biotechnological applications and methods to increase sustainability of ecosystem-based aquaculture production, including alternative preventive and therapeutic measures to enhance environmental welfare; sustainable production technologies for feed supply; intensive farming through recirculating farming systems with zero wastes; and integration of new, low environmental impact feed ingredients including alternatives for fishmeal and fish oil.
References Boonyaratpalin, M., Thongrod, S., Supamattaya, K., Britton, G.E., Schlipalius, L., 2001. Effects of β-carotene source, Dunaliella salina, and astaxanthin on pigmentation, growth, survival and health of Penaeus monodon. Aquacult. Res. 32, 182 190. Chapman, V.J., 1970. Seaweeds and Their Uses. Methuen & Co Ltd, London, 304 pp. Dhar, A.K., Manna, S.K., Allnutt, F.C.T., 2014. Viral vaccines for farmed finfish. Virus Disease 25 (1), 1 17. Dona, A.I., Arvanitoyannis, I.S., 2009. Health risks of genetically modified foods. Crit. Rev. Food Sci. Nutr. 49 (2), 164 175. Dunham, R.A., 2010. Aquaculture and Fisheries Biotechnology, Genetic Approaches, second ed. Stylus Cabi Publishing, 495 pp. FAO, 2018. The State of World Fisheries and Aquaculture. FAO, Rome, 227 pp. Kim, S.K., 2015. Handbook of Marine Biotechnology. Springer, Berlin, Heidelberg. Lorenz, R.T., 1998. A review of the carotenoid, astaxanthin, as a pigment source and vitamin for cultured Penaeus prawn. NatuRosea Tech. Bullet. 51, 1 7. Nakano, T., Miura, Y., Wazawa, M., Sato, M., Takeuchi, M., 1999. Red yeast Phaffia rhodozyma reduces susceptibility of liver homogenate to lipid peroxidation in rainbow trout. Fish. Sci. 65, 961 962. Quentin, R.G., Ray, H., Dale, S., Maree, T., Meryl, W., 2010. Handbook of Marine Fisheries Conservation and Management. Oxford University Press, Oxford, New York, 770 pp. Rasmussen, R.S., Morrissey, M.T., 2007. Marine biotechnology for production of food ingredients. In: Taylor, S.L. (Ed.), Advances in Food and Nutrition Research. Elsevier, New York, pp. 237 292. Schiedt, K., 1998. Absorption and metabolism of carotenoids in birds, fish and crustaceans. In: Britton, G., Liaaen-Jensen, S., Pfander, H. (Eds.), Carotenoids Biosynthesis and Metabolism. Birkha¨user, Basel, pp. 285 358.
References
Shahidi, F., Metusalach, J., Brown, J.A., 1998. Carotenoid pigments in seafoods and aquaculture. Crit. Rev. Food Sci. 38, 1 67. Shpigel, M., McBride, S.C., Marciano, S., Lipatch, I., 2004. The effect of photoperiod and temperature on the production of European sea urchin, Paracentrotus lividus. Aquaculture 245, 101 109. Suleria, H.A., Osborne, S., Masci, P., Gobe, G., 2015. Marine-based nutraceuticals: an innovative trend in the food and supplement industries. Mar. Drugs 13, 6336 6351. Toyomizu, M., Sato, K., Taroda, H., Kato, T., Akiba, Y., 2001. Effects of dietary Spirulina on meat color inmuscle of broiler chickens. Br. Poultry Sci. 42, 197 202. Wakchaure, R., Ganguly, S., Qadri, K., Praveen, P.K., Mahajan, T., 2015. Importance of transgenic fish to global aquaculture: a review. Fish. Aquac. J. 6, 124. Wilkins, N.P., 1981. The rationale and relevance of genetics in aquaculture: an overview. Aquaculture 22, 209 228. Zbikowska, H.M., 2003. Fish can be first—advances in fish transgenesis for commercial applications. Transgenic Res. 12 (4), 379 389.
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