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Microorganisms and antibiotic production
CHAPTER
Microorganisms and antibiotic production
1
Kanwal Rehman1, Sania Niaz1, 2, Ayesha Tahir1,2, Muhammad Sajid Hamid Akash3 1
Department of Pharmacy, University of Agriculture, Faisalabad, Pakistan; 2Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad, Pakistan; 3Department of Pharmaceutical Chemistry, Government College University Faisalabad, Faisalabad, Pakistan
1.1 Introduction Microorganisms are organisms or infectious agents of microscopic or submicroscopic size, which include bacteria, fungi, protozoans, and viruses. For the treatment of infections, antimicrobial drugs are valuable due to selectivity of their toxicity, thereby having capability to kill the invading microorganisms without harming the host cells. Antimicrobial medicines can be classified according to their action against the microorganisms. For example, antibiotics are used against bacteria, whereas antifungals are specifically used against fungi. The term probiotic was introduced by Lilly and Stillwell (Lilly and Stillwell, 1965).
1.2 Probiotics The use of probiotics for their health benefits is increasing worldwide (Agheyisi, 2005). The word probiotic is derived from the Greek word meaning for life and has had several different meanings over the years. Improving the host health by consumption of live microorganisms provides a basic concept of a probiotic. A probiotic can be defined as microorganism introduced into the body in sufficient quantity for its beneficial qualities into the host. Gut health or microflora can be improved by the utilization of typical microorganisms that are present in fermented products (Hill et al., 2014; Ndowa et al., 2012). According to the mechanistic approach, disorder or imbalance of important intestinal microflora leads to many gastrointestinal infirmity or infections. Probiotics are viable microbial cultures that maintain or balance the microflora of intestine, correct the microbial dysfunction, and enhance the host health and well-being (Fuller, 1989; Rokka and Rantama¨ki, 2010). Two of the most common microbes that are widely used as probiotics are Lactobacillus and Bifidobacteria strains. Growth of the concerned microorganism is stimulated by using the bacterial culture of probiotics, which improves the natural defensive mechanism of the body and also disrupts the harmful bacteria (Dunne, 2001). Probiotics have shown a curative role against cancer, and they also have been shown to reduce cholesterol levels, modify lactose intolerance, and enhance immunity (Kailasapathy and Chin, 2000). As probiotics boost immunity, they provide beneficial health effects by the stimulation of cellAntibiotics and Antimicrobial Resistance Genes in the Environment. https://doi.org/10.1016/B978-0-12-818882-8.00001-2 Copyright © 2020 Elsevier Inc. All rights reserved.
1
2
Chapter 1 Microorganisms and antibiotic production
mediated immune responses as well as enhance the antibody secretions. Probiotics are selected according to the protection point of view against microbial pathogens (Cross, 2002) and also play a vital role in maintaining the overweight of an obese adult (Kadooka et al., 2010).
1.3 Prebiotics Prebiotic concepts were introduced in 1995 by Gibson and Roberfroid as a substitute approach to alter or modify the microbiota of the gut (Gibson and Roberfroid, 1995). A prebiotic is a nondigestible food ingredient, usually bifidobacteria and lactobacilli, that beneficially affects the host by enhancing the growth and/or activity of one or a limited number of specific species of bacteria in the gut, thus strengthening the host health. They are indigestible by human enzymes because they have short-chain carbohydrates (SCCs), so-called resistant SCCs (Quigley et al., 1999). To be considered as a prebiotic, a food ingredient must have specific properties. For example, (1) it should be resistant by passing the upper portion of gastrointestinal track for the absorption and hydrolysis; (2) it should provide a favorable environment by modifying the microflora of the colon and provide more healthy and favorable composition there; and (3) it should show specific property of selective substrate for one or a specific amount of colon bacteria (Park and Kroll, 1993). Hence there are numerous potential applications of prebiotics. Prebiotics should be resistant to being hydrolyzed by intestinal enzymes of the human but should be fermented by specific bacteria and should have fruitful effects for the host. Upon administration, prebiotics should have beneficial outcomes including lowering the permeability of intestine, decreasing triglyceride levels, and improving glucose levels after eating (Cani et al., 2009; Gibson and Roberfroid, 1995). Prebiotics are widely used as a supplement and can be formulated in various ways such as syrups or powder and also into different food products, particularly in bread and yogurt, that provide beneficial health effects by enhancing the minerals’ bioavailability (Roberfroid et al., 2010). They have also been recommended for improved bone and mineral metabolism.
1.4 Symbiotics It has been suggested that symbiotics are the combination of probiotics and prebiotics, not only comprising the combined effects of these two probiotics and prebiotics but also purposed to have a synergistic effect (Rafter et al., 2007).
1.5 Antibiotics Many of the antibiotics are the essential excretions of environmental bacteria and fungi. At present, these antibiotics are used as a major source of human medicines for the treatment of infections (Kieser et al., 2000).
1.5.1 Classification of antibiotics The most important classification of antibiotics is based on their spectrum, mode of action, and molecular structure. There are certain ways to classify antibiotics (Caldero´n and Sabundayo, 2007), notably, one method is based on their route of administration such as topically, orally, or as an
1.7 Production of antibiotics
3
injectable. Other antibiotics that are related to the same structural class will show analogous patterning of efficiency, allergic side effects, and toxicity. Some common classes of antibiotics like macrolides, quinolones, tetracyclines, aminoglycosides, sulfonamides, oxazolidinones, glycopeptides, and betalactam are based on their molecular and chemical structures (Adzitey, 2015; Frank and Tacconelli, 2012; Van Hoek et al., 2011). For many years, antibiotics have proven efficacious in providing a curative response for many contagious diseases. Antibiotics include composites that hinder the growth of microorganisms, which are considered as “antimicrobial agents.” Several natural antibiotics can also be used in the treatment of numerous diseases.
1.5.2 Mechanisms of antibiotic resistance Antibiotic resistance came into existence between 1940 and 1970. There are several ways for the development of antibiotic resistance that are described in the following subsections.
1.5.3 Enzymatic inactivation In enzymatic inactivation, the primitive enzyme undergoes modification by reacting with the antibiotic and then the antibiotic cannot kill the microorganism. The most common example is b-lactamase enzymes which causes hydrolysis of antibiotics and ultimately leads to antibiotic resistance against penicillins and cephalosporins.
1.5.4 Drug elimination In Pseudomonas aeruginosa and Acinetobacter species, the most important resistance mechanism is drug elimination due to the excitation of efflux pump. Bacteria activate the proteins that cause the removal of compounds from periplasm to outside of the cell to remove the antibiotics.
1.5.5 Permeability changes Due to the alterations in outer membrane portability, there is a decrease in uptake of administered antibiotics, due to which the adequate access to the antibiotics is blocked.
1.6 Modifications of antimicrobial targets Three different types of antibiotic adjuvants have been invented that can be used to block the antibiotic resistance mechanisms. These may include the (1) inhibitors of b-lactamases, (2) inhibitors of efflux pump, and (3) permeabilization of outer membrane (Clatworthy et al., 2007; Rasko and Sperandio, 2010). The World Health Organization has recommended an antimicrobial resistance control policy that includes increased supervision, development of new molecules, and rational use of antibiotics.
1.7 Production of antibiotics Most antibiotics are produced by staged fermentations in which strains of microorganisms producing high yields are grown under optimum conditions. It is important that the organism that is used for the
4
Chapter 1 Microorganisms and antibiotic production
production of antibiotic must be identified and isolated. The microorganism must be grown enough for the purification and chemical analysis of the isolated antibiotics. Sterile conditions must be followed during the purification and isolation of antibiotics because contamination by foreign microbes may ruin the fermentation of the antibiotics. Following are the most commonly used techniques for the production of antibiotics.
1.7.1 Natural production of antibiotics In natural production, fermentation technique is used for the production of antibiotics. The most common example of an antibiotic produced by this method is penicillin.
1.7.2 Semisynthetic production of antibiotics This method is used for the production of natural antibiotics, for example, ampicillin.
1.7.3 Synthetic production of antibiotics This method is used for the production of antibiotics in a laboratory. For example, the production of quinoline is done by this method.
1.7.4 Industrial production of antibiotics In this technique, the source microorganism is grown in large containers containing a liquid growth medium. In this technique, the oxygen concentration, temperature, pH, and nutrient levels must be optimum. As the antibiotics are secondary metabolites, their production must be controlled to ensure that the maximum yield of antibiotics is obtained before the cells die.
1.7.5 Methods for increased production of antibiotics Species for the production of specific antibiotics are often genetically modified to yield the maximum amounts of antibiotics. Mutations and gene amplification techniques are used to increase the production of antibiotics.
1.8 Stability of antimicrobial agents According to several research studies, many kinds of encapsulation procedures and materials are used for microencapsulation and coating of antibiotics (He´brard et al., 2010; Nag et al., 2011; Papagianni and Anastasiadou, 2009). To preserve the antibiotics from the unpleasant conditions in the intestinal tract, microencapsulation technique is widely used (Anal and Singh, 2007; Kailasapathy, 2002). Microencapsulation technique plays an important role by separating the core material from environmental conditions until it gets released, thereby modifying stability and viability and improving shelf life and helping to provide the controlled and sustained release of encapsulated products. The outer structure is formed by microencapsulation technique around the core. This property provides a core with characteristics of controlled-release product under favorable
References
5
environmental conditions and also provides a way for small molecules to pass out of and into the membrane. At the time of release of encapsulated core material at the favorable site, it follows different mechanistic approaches including dissolution of the cell wall, melting of the cell wall, diffusion through the wall, and breakage of the cell wall (F. Gibbs, 1999; Franjione and Vasishtha, 1995).
1.9 Conclusion For the better efficacy of antimicrobial agents against microorganisms, efficient methods should be chosen for the production and purification of antimicrobial agents. As the stability of antimicrobial agents is a major concern, it is mandatory that appropriate technique should be adopted for the encapsulation of antimicrobial agents.
References Adzitey, F., 2015. Antibiotic Classes and Antibiotic Susceptibility of Bacterial Isolates From Selected Poultry; a Mini Review. Agheyisi, R., 2005. Ga-121 Probiotics: Ingredients, Supplements, Foods. Publisher BCC Research Inc. Anal, A.K., Singh, H., 2007. Recent advances in microencapsulation of probiotics for industrial applications and targeted delivery. Trends in Food Science & Technology 18, 240e251. Caldero´n, C.B., Sabundayo, B.P., 2007. Antimicrobial classifications: drugs for bugs. In: Schwalbe, R., SteeleMoore, L., Goodwin, A.C. (Eds.), Antimicrobial Susceptibility Testing Protocols. CRC Press. Taylor & Frances Group. Cani, P.D., Lecourt, E., Dewulf, E.M., Sohet, F.M., Pachikian, B.D., Naslain, D., De Backer, F., Neyrinck, A.M., Delzenne, N.M., 2009. Gut microbiota fermentation of prebiotics increases satietogenic and incretin gut peptide production with consequences for appetite sensation and glucose response after a meal. The American Journal of Clinical Nutrition 90, 1236e1243. Clatworthy, A.E., Pierson, E., Hung, D.T., 2007. Targeting virulence: a new paradigm for antimicrobial therapy. Nature Chemical Biology 3, 541. Cross, M.L., 2002. Microbes versus microbes: immune signals generated by probiotic lactobacilli and their role in protection against microbial pathogens. FEMS Immunology and Medical Microbiology 34, 245e253. Dunne, C., 2001. Adaptation of bacteria to the intestinal niche: probiotics and gut disorder. Inflammatory Bowel Diseases 7, 136e145. Franjione, J., Vasishtha, N., 1995. The art and science of microencapsulation. Technology Today 2, 1e6. Frank, U., Tacconelli, E., 2012. The Daschner Guide to In-Hospital Antibiotic Therapy: European Standards. Springer Science & Business Media. Fuller, R., 1989. Probiotics in man and animals. Journal of Applied Bacteriology 66, 365e378. Gibbs, B.F., Kermasha, S., Alli, I., Mulligan, C.N., 1999. Encapsulation in the food industry: a review. International Journal of Food Sciences and Nutrition 50, 213e224. Gibson, G.R., Roberfroid, M.B., 1995. Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. Journal of Nutrition 125, 1401e1412. He´brard, G., Hoffart, V., Beyssac, E., Cardot, J.-M., Alric, M., Subirade, M., 2010. Coated whey protein/alginate microparticles as oral controlled delivery systems for probiotic yeast. Journal of Microencapsulation 27, 292e302.
6
Chapter 1 Microorganisms and antibiotic production
Hill, C., Guarner, F., Reid, G., Gibson, G.R., Merenstein, D.J., Pot, B., Morelli, L., Canani, R.B., Flint, H.J., Salminen, S., 2014. Expert consensus document: the International Scientific Association for Probiotics and Prebiotics consensus statement on the scope and appropriate use of the term probiotic. Nature Reviews Gastroenterology & Hepatology 11, 506. Kadooka, Y., Sato, M., Imaizumi, K., Ogawa, A., Ikuyama, K., Akai, Y., Okano, M., Kagoshima, M., Tsuchida, T., 2010. Regulation of abdominal adiposity by probiotics (Lactobacillus gasseri SBT2055) in adults with obese tendencies in a randomized controlled trial. European Journal of Clinical Nutrition 64, 636. Kailasapathy, K., 2002. Microencapsulation of probiotic bacteria: technology and potential applications. Current Issues in Intestinal Microbiology 3, 39e48. Kailasapathy, K., Chin, J., 2000. Survival and therapeutic potential of probiotic organisms with reference to Lactobacillus acidophilus and Bifidobacterium spp. Immunology & Cell Biology 78, 80e88. Kieser, T., Bibb, M.J., Buttner, M.J., Chater, K.F., Hopwood, D.A., 2000. Practical Streptomyces Genetics. John Innes Foundation, Norwich. Lilly, D.M., Stillwell, R.H., 1965. Probiotics: growth-promoting factors produced by microorganisms. Science 147, 747e748. Nag, A., Han, K.-S., Singh, H., 2011. Microencapsulation of probiotic bacteria using pH-induced gelation of sodium caseinate and gellan gum. International Dairy Journal 21, 247e253. Ndowa, F., Lusti-Narasimhan, M., Unemo, M., 2012. The Serious Threat of Multidrug-Resistant and Untreatable Gonorrhoea: The Pressing Need for Global Action to Control the Spread of Antimicrobial Resistance, and Mitigate the Impact on Sexual and Reproductive Health. BMJ Publishing Group Ltd. Papagianni, M., Anastasiadou, S., 2009. Encapsulation of Pediococcus acidilactici cells in corn and olive oil microcapsules emulsified by peptides and stabilized with xanthan in oil-in-water emulsions: studies on cell viability under gastro-intestinal simulating conditions. Enzyme and Microbial Technology 45, 514e522. Park, S.F., Kroll, R.G., 1993. Expression of listeriolysin and phosphatidylinositol-specific phospholipase C is repressed by the plant-derived molecule cellobiose in Listeria monocytogenes. Molecular Microbiology 8, 653e661. Quigley, M.E., Hudson, G.J., Englyst, H.N., 1999. Determination of resistant short-chain carbohydrates (nondigestible oligosaccharides) using gaseliquid chromatography. Food Chemistry 65, 381e390. Rafter, J., Bennett, M., Caderni, G., Clune, Y., Hughes, R., Karlsson, P.C., Klinder, A., O’Riordan, M., O’Sullivan, G.C., Pool-Zobel, B., 2007. Dietary synbiotics reduce cancer risk factors in polypectomized and colon cancer patients. The American journal of clinical nutrition 85, 488e496. Rasko, D.A., Sperandio, V., 2010. Anti-virulence strategies to combat bacteria-mediated disease. Nature Reviews Drug Discovery 9, 117. Roberfroid, M., Gibson, G.R., Hoyles, L., McCartney, A.L., Rastall, R., Rowland, I., Wolvers, D., Watzl, B., Szajewska, H., Stahl, B., 2010. Prebiotic effects: metabolic and health benefits. British Journal of Nutrition 104, S1eS63. Rokka, S., Rantama¨ki, P., 2010. Protecting probiotic bacteria by microencapsulation: challenges for industrial applications. European Food Research and Technology 231, 1e12. Van Hoek, A.H., Mevius, D., Guerra, B., Mullany, P., Roberts, A.P., Aarts, H.J., 2011. Acquired antibiotic resistance genes: an overview. Frontiers in Microbiology 2, 203.
Microorganisms and antibiotic production
1
Kanwal Rehman1, Sania Niaz1, 2, Ayesha Tahir1,2, Muhammad Sajid Hamid Akash3 1
Department of Pharmacy, University of Agriculture, Faisalabad, Pakistan; 2Institute of Physiology and Pharmacology, University of Agriculture, Faisalabad, Pakistan; 3Department of Pharmaceutical Chemistry, Government College University Faisalabad, Faisalabad, Pakistan
1.1 Introduction Microorganisms are organisms or infectious agents of microscopic or submicroscopic size, which include bacteria, fungi, protozoans, and viruses. For the treatment of infections, antimicrobial drugs are valuable due to selectivity of their toxicity, thereby having capability to kill the invading microorganisms without harming the host cells. Antimicrobial medicines can be classified according to their action against the microorganisms. For example, antibiotics are used against bacteria, whereas antifungals are specifically used against fungi. The term probiotic was introduced by Lilly and Stillwell (Lilly and Stillwell, 1965).
1.2 Probiotics The use of probiotics for their health benefits is increasing worldwide (Agheyisi, 2005). The word probiotic is derived from the Greek word meaning for life and has had several different meanings over the years. Improving the host health by consumption of live microorganisms provides a basic concept of a probiotic. A probiotic can be defined as microorganism introduced into the body in sufficient quantity for its beneficial qualities into the host. Gut health or microflora can be improved by the utilization of typical microorganisms that are present in fermented products (Hill et al., 2014; Ndowa et al., 2012). According to the mechanistic approach, disorder or imbalance of important intestinal microflora leads to many gastrointestinal infirmity or infections. Probiotics are viable microbial cultures that maintain or balance the microflora of intestine, correct the microbial dysfunction, and enhance the host health and well-being (Fuller, 1989; Rokka and Rantama¨ki, 2010). Two of the most common microbes that are widely used as probiotics are Lactobacillus and Bifidobacteria strains. Growth of the concerned microorganism is stimulated by using the bacterial culture of probiotics, which improves the natural defensive mechanism of the body and also disrupts the harmful bacteria (Dunne, 2001). Probiotics have shown a curative role against cancer, and they also have been shown to reduce cholesterol levels, modify lactose intolerance, and enhance immunity (Kailasapathy and Chin, 2000). As probiotics boost immunity, they provide beneficial health effects by the stimulation of cellAntibiotics and Antimicrobial Resistance Genes in the Environment. https://doi.org/10.1016/B978-0-12-818882-8.00001-2 Copyright © 2020 Elsevier Inc. All rights reserved.
1
2
Chapter 1 Microorganisms and antibiotic production
mediated immune responses as well as enhance the antibody secretions. Probiotics are selected according to the protection point of view against microbial pathogens (Cross, 2002) and also play a vital role in maintaining the overweight of an obese adult (Kadooka et al., 2010).
1.3 Prebiotics Prebiotic concepts were introduced in 1995 by Gibson and Roberfroid as a substitute approach to alter or modify the microbiota of the gut (Gibson and Roberfroid, 1995). A prebiotic is a nondigestible food ingredient, usually bifidobacteria and lactobacilli, that beneficially affects the host by enhancing the growth and/or activity of one or a limited number of specific species of bacteria in the gut, thus strengthening the host health. They are indigestible by human enzymes because they have short-chain carbohydrates (SCCs), so-called resistant SCCs (Quigley et al., 1999). To be considered as a prebiotic, a food ingredient must have specific properties. For example, (1) it should be resistant by passing the upper portion of gastrointestinal track for the absorption and hydrolysis; (2) it should provide a favorable environment by modifying the microflora of the colon and provide more healthy and favorable composition there; and (3) it should show specific property of selective substrate for one or a specific amount of colon bacteria (Park and Kroll, 1993). Hence there are numerous potential applications of prebiotics. Prebiotics should be resistant to being hydrolyzed by intestinal enzymes of the human but should be fermented by specific bacteria and should have fruitful effects for the host. Upon administration, prebiotics should have beneficial outcomes including lowering the permeability of intestine, decreasing triglyceride levels, and improving glucose levels after eating (Cani et al., 2009; Gibson and Roberfroid, 1995). Prebiotics are widely used as a supplement and can be formulated in various ways such as syrups or powder and also into different food products, particularly in bread and yogurt, that provide beneficial health effects by enhancing the minerals’ bioavailability (Roberfroid et al., 2010). They have also been recommended for improved bone and mineral metabolism.
1.4 Symbiotics It has been suggested that symbiotics are the combination of probiotics and prebiotics, not only comprising the combined effects of these two probiotics and prebiotics but also purposed to have a synergistic effect (Rafter et al., 2007).
1.5 Antibiotics Many of the antibiotics are the essential excretions of environmental bacteria and fungi. At present, these antibiotics are used as a major source of human medicines for the treatment of infections (Kieser et al., 2000).
1.5.1 Classification of antibiotics The most important classification of antibiotics is based on their spectrum, mode of action, and molecular structure. There are certain ways to classify antibiotics (Caldero´n and Sabundayo, 2007), notably, one method is based on their route of administration such as topically, orally, or as an
1.7 Production of antibiotics
3
injectable. Other antibiotics that are related to the same structural class will show analogous patterning of efficiency, allergic side effects, and toxicity. Some common classes of antibiotics like macrolides, quinolones, tetracyclines, aminoglycosides, sulfonamides, oxazolidinones, glycopeptides, and betalactam are based on their molecular and chemical structures (Adzitey, 2015; Frank and Tacconelli, 2012; Van Hoek et al., 2011). For many years, antibiotics have proven efficacious in providing a curative response for many contagious diseases. Antibiotics include composites that hinder the growth of microorganisms, which are considered as “antimicrobial agents.” Several natural antibiotics can also be used in the treatment of numerous diseases.
1.5.2 Mechanisms of antibiotic resistance Antibiotic resistance came into existence between 1940 and 1970. There are several ways for the development of antibiotic resistance that are described in the following subsections.
1.5.3 Enzymatic inactivation In enzymatic inactivation, the primitive enzyme undergoes modification by reacting with the antibiotic and then the antibiotic cannot kill the microorganism. The most common example is b-lactamase enzymes which causes hydrolysis of antibiotics and ultimately leads to antibiotic resistance against penicillins and cephalosporins.
1.5.4 Drug elimination In Pseudomonas aeruginosa and Acinetobacter species, the most important resistance mechanism is drug elimination due to the excitation of efflux pump. Bacteria activate the proteins that cause the removal of compounds from periplasm to outside of the cell to remove the antibiotics.
1.5.5 Permeability changes Due to the alterations in outer membrane portability, there is a decrease in uptake of administered antibiotics, due to which the adequate access to the antibiotics is blocked.
1.6 Modifications of antimicrobial targets Three different types of antibiotic adjuvants have been invented that can be used to block the antibiotic resistance mechanisms. These may include the (1) inhibitors of b-lactamases, (2) inhibitors of efflux pump, and (3) permeabilization of outer membrane (Clatworthy et al., 2007; Rasko and Sperandio, 2010). The World Health Organization has recommended an antimicrobial resistance control policy that includes increased supervision, development of new molecules, and rational use of antibiotics.
1.7 Production of antibiotics Most antibiotics are produced by staged fermentations in which strains of microorganisms producing high yields are grown under optimum conditions. It is important that the organism that is used for the
4
Chapter 1 Microorganisms and antibiotic production
production of antibiotic must be identified and isolated. The microorganism must be grown enough for the purification and chemical analysis of the isolated antibiotics. Sterile conditions must be followed during the purification and isolation of antibiotics because contamination by foreign microbes may ruin the fermentation of the antibiotics. Following are the most commonly used techniques for the production of antibiotics.
1.7.1 Natural production of antibiotics In natural production, fermentation technique is used for the production of antibiotics. The most common example of an antibiotic produced by this method is penicillin.
1.7.2 Semisynthetic production of antibiotics This method is used for the production of natural antibiotics, for example, ampicillin.
1.7.3 Synthetic production of antibiotics This method is used for the production of antibiotics in a laboratory. For example, the production of quinoline is done by this method.
1.7.4 Industrial production of antibiotics In this technique, the source microorganism is grown in large containers containing a liquid growth medium. In this technique, the oxygen concentration, temperature, pH, and nutrient levels must be optimum. As the antibiotics are secondary metabolites, their production must be controlled to ensure that the maximum yield of antibiotics is obtained before the cells die.
1.7.5 Methods for increased production of antibiotics Species for the production of specific antibiotics are often genetically modified to yield the maximum amounts of antibiotics. Mutations and gene amplification techniques are used to increase the production of antibiotics.
1.8 Stability of antimicrobial agents According to several research studies, many kinds of encapsulation procedures and materials are used for microencapsulation and coating of antibiotics (He´brard et al., 2010; Nag et al., 2011; Papagianni and Anastasiadou, 2009). To preserve the antibiotics from the unpleasant conditions in the intestinal tract, microencapsulation technique is widely used (Anal and Singh, 2007; Kailasapathy, 2002). Microencapsulation technique plays an important role by separating the core material from environmental conditions until it gets released, thereby modifying stability and viability and improving shelf life and helping to provide the controlled and sustained release of encapsulated products. The outer structure is formed by microencapsulation technique around the core. This property provides a core with characteristics of controlled-release product under favorable
References
5
environmental conditions and also provides a way for small molecules to pass out of and into the membrane. At the time of release of encapsulated core material at the favorable site, it follows different mechanistic approaches including dissolution of the cell wall, melting of the cell wall, diffusion through the wall, and breakage of the cell wall (F. Gibbs, 1999; Franjione and Vasishtha, 1995).
1.9 Conclusion For the better efficacy of antimicrobial agents against microorganisms, efficient methods should be chosen for the production and purification of antimicrobial agents. As the stability of antimicrobial agents is a major concern, it is mandatory that appropriate technique should be adopted for the encapsulation of antimicrobial agents.
References Adzitey, F., 2015. Antibiotic Classes and Antibiotic Susceptibility of Bacterial Isolates From Selected Poultry; a Mini Review. Agheyisi, R., 2005. Ga-121 Probiotics: Ingredients, Supplements, Foods. Publisher BCC Research Inc. Anal, A.K., Singh, H., 2007. Recent advances in microencapsulation of probiotics for industrial applications and targeted delivery. Trends in Food Science & Technology 18, 240e251. Caldero´n, C.B., Sabundayo, B.P., 2007. Antimicrobial classifications: drugs for bugs. In: Schwalbe, R., SteeleMoore, L., Goodwin, A.C. (Eds.), Antimicrobial Susceptibility Testing Protocols. CRC Press. Taylor & Frances Group. Cani, P.D., Lecourt, E., Dewulf, E.M., Sohet, F.M., Pachikian, B.D., Naslain, D., De Backer, F., Neyrinck, A.M., Delzenne, N.M., 2009. Gut microbiota fermentation of prebiotics increases satietogenic and incretin gut peptide production with consequences for appetite sensation and glucose response after a meal. The American Journal of Clinical Nutrition 90, 1236e1243. Clatworthy, A.E., Pierson, E., Hung, D.T., 2007. Targeting virulence: a new paradigm for antimicrobial therapy. Nature Chemical Biology 3, 541. Cross, M.L., 2002. Microbes versus microbes: immune signals generated by probiotic lactobacilli and their role in protection against microbial pathogens. FEMS Immunology and Medical Microbiology 34, 245e253. Dunne, C., 2001. Adaptation of bacteria to the intestinal niche: probiotics and gut disorder. Inflammatory Bowel Diseases 7, 136e145. Franjione, J., Vasishtha, N., 1995. The art and science of microencapsulation. Technology Today 2, 1e6. Frank, U., Tacconelli, E., 2012. The Daschner Guide to In-Hospital Antibiotic Therapy: European Standards. Springer Science & Business Media. Fuller, R., 1989. Probiotics in man and animals. Journal of Applied Bacteriology 66, 365e378. Gibbs, B.F., Kermasha, S., Alli, I., Mulligan, C.N., 1999. Encapsulation in the food industry: a review. International Journal of Food Sciences and Nutrition 50, 213e224. Gibson, G.R., Roberfroid, M.B., 1995. Dietary modulation of the human colonic microbiota: introducing the concept of prebiotics. Journal of Nutrition 125, 1401e1412. He´brard, G., Hoffart, V., Beyssac, E., Cardot, J.-M., Alric, M., Subirade, M., 2010. Coated whey protein/alginate microparticles as oral controlled delivery systems for probiotic yeast. Journal of Microencapsulation 27, 292e302.
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Chapter 1 Microorganisms and antibiotic production
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