- Email: [email protected]
Something old, something new
T I B T E C H - A U G U S T 1988 [Vol. 6]
ing of the requirements for substrate binding and catalysis is essential to improve the hydrolytic rate of enzymes. Using site-directed mutegenesis, modified cellulase enzyme complexes have been constructed that have higher hydrolytic activity than the native forms. Within the cellulase complex, synergism between cellobiohydrolase and endoglucanase is independent of their ratio in a crude mixture but is dependent on the level of saturation of substrate with enzyme (J. Woodward, Oak Ridge National Laboratory). Utilization of xylan (which is the major component of hemicellulose in hardwood) and lignin is of vital economic importance for all biological conversion of wood. Microbial conversion of hemicellulose hydrolysates from steam-treated birch w o o d to single cell protein, ethanol and xylonic acid has been successful only at dilute concentrations because of the inhibitory effect on the microorganisms of degradation products formed during the pretreatment (J. Buchert, VTT Biotechical Laboratory, Finland). Aromatic aldehyde oxidase from Streptomyces viridosporus was identified as a suitable enzyme for lignin biotransformation (D. L. Crawford and L. A. Deobald, University of Idaho). Perhaps the most commercially significant research in biological waste treatment is the in-situ treatment of contaminated underground petroleum products. The factors having major impact on treatment methods are the characteristicg of the soil and microorganisms at the contaminated site and the ability to circulate aerated nutrient solutions effectively (A. W. Bourquin, Ecova Corp.).
presentations dealt with continuous bioreactors. Among the more common designs is the immobilizedbiocatalyst, fluidized-bed reactor which generally gives high conversion rates at relatively low biocatalyst make-up requirements. An example is the fermentor used in the conversion of dextrose to ethanol and carbon dioxide - a columnar, threephase, fluidized-bed reactor packed with immobilized Z. mobilis (B. H. Davison, Oak Ridge National Laboratory). It was suggested that process economic evaluation using computer simulation should be conducted in parallel with laboratory research, especially for complex processes such as the bioconversion of w o o d to alcohols (N. D. Hinman, Solar Energy Research Institute; Q. Nguyen, Forintek Canada Corp.). This should help researchers focus their objectives more effectively. For example, in a fermentation process, the productivity does not have as much of an impact on the overall production cost as do product yield and product concentration. This brought up the familiar issue of the need for cooperation between engineers and microbiologists to improve the chances of success in the development of economically viable processes. Another old theme concerned bioprocessing of commodity chemicals as a potential alternative solution for improving the competitiveness of the US chemical industry (via new products, and improved process economics) and for securing feedstocks should there be a disruption in imported oil supply. Ethanol was identified as the most important feedstock because its derivatives could account for a third of all synthetic organic chemicals. However, further research is required to overcome the technical constraints (slow conversion rate, low product yield and concentration, sterile environment) which currently make biomass commodity chemicals uneconomical.
Bioengineering
Biodegradable plastics
Process economic evaluation and bioreactor design were among the predominant themes of the 'Bioengineering Research' session. Several
The 'Biological Production of Materials' session provided several interesting papers on biodegradable plastics. Environmental concerns
Something old, something n e w Biomass conversion is, perhaps, one of the less glamorous parts of biotechnology. Nevertheless, in terms of volume of research work and diversity of approach, it is one of the biggest. Many of its various themes received an airing recently in Gatlinburg, Tennessee*.
Lignocellulose processing In the area of thermal and chemical processing of lignocellulosic materials two major processing apprgaches were presented: acid hydrolysis and thermochemical pretreatment for subsequent enzymatic hydrolysis. The traditional two-stage sulfuric acid hydrolysis is still being improved with emphasis on recycling of acid and improved reactor design. It was reported that sulfuric acid recovery by electrodialysis from wood sugar hydrolysates is technically feasible (I. Goldstein, North Carolina State University). Continuous plug flow reactors and semi-batch percolation reactors are employed to produce high sugar concentrations in the hydrolysates (P. Bergeron, Solar Energy Research Institute, Golden). Thermochemical rather than enzymatic pretreatment is still the choice of many researchers: high temperature steam pretreatment with and without acid catalyst (G. D. McGinnis, Mississippi State University; W. Schwald, Forintek Canada Corp.); dilute acid prehydrolysis (A. O. Converse, Dartmouth College, Hanover; R. Torget, Solar Energy Research Institute); and pretreatment with organic solvent (H. L. Chum, Solar Energy Research Institute).
Applied biology The symposium section on applied biology covered a wide spectrum of research. According to S. Shoemaker (Genencor Inc.), a better understand*Tenth Symposium on Biotechnology for Fuels and Chemicals, Gatlinburg, USA; 16-20 May 1988.
© 1988, Elsevier Publications, Cambridge
0167 -9430/88/$02.00
TIBTECH
have forced several US cities and states to restrict the use of nonbiodegradable plastic for packaging. Other states are expected to take similar action. This has created a lot of research interest in biodegradable plastics as the potential market is enormous. Unlike the elusive fuel bioethanol market which must compete with gasoline, methanol and ethanol produced from ethylene, biodegradable plastics may have a market niche. Of some 'biodegradable' plastics currently on the market, only the filler (starch or cellulose) and []
[]
the plasticizers are biodegradable. Blending poly(lactic acid) (which can be produced from starch or hardwood hemicellulose) with thermoplastics such as polystyrene, polyethylene and polypropylene will impart biodegradability while preserving mechanical and thermal properties (R. Narayan, Purdue University). Feedstocks for biodegradable plastics can also be produced via microbial oxygenation of aromatics (D. W. Ribbons, hnperial College University of London; D.R. Lloyd, ICI-America). The symposium successfully pro-
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Biotechnology in agriculture: a worldwide upheaval Without food, m a n k i n d has little use for medicine or industry. Agriculture, the oldest biotechnology, is therefore also the most fundamental to our well-being. The application of modern methods of biotechnology represents just the latest step in the march of technology in agriculture. But it coincides with a growing public awareness of the disadvantages that have accompanied previous progress - the environmental, economic and ethical problems that result from intensive farming in developed countries. There is a growing scientific awareness that biotechnology has applications in farming in the developing countries. In the next few pages, Allen Dines' snapshot of public feeling in the US and Joske Bunders' appraisal of appropriate agricultural biotechnology form a r~sum6 of the changing climate in farming. For at least the last four years, the public's opinion of biotechnology has consumed tremendous energy among those in the industry and the scientific community as well as those who follow developments in the field. In the area of agricultural biotechnology, public attention has focused principally on the issue of the potential environmental hazards of field testing genetically engineered organisms. If the impression of public opinion expressed at the recent US Department of Agriculture (USDA) conference on Agricultural Biotechnology and the Public* is any indication, we may soon see a change in this focus to broader issues of *USDA Conference on Agricultural Biotechnology and The Public, Minneapolis, USA; 17-18 May 1988.
social and economic impacts of biotechnology on the farm and on our food production system. In the words of the USDA program description, the conference covered 'the explosive fusion ofbiotechnology with farming and what it means to the public'. The department assembled a broad and balanced program that provided those attending the conference with a diverse selection of views on what agricultural biotechnology can and cannot do, as well as what it should or should not be doing. Participants were largely a mixture of the biotechnology 'regulars' (company and agency people who are always in attendance at these events) and new participants from state government, the media and public interest groups seeking to learn about biotechnology.
(~ 1988, Elsevier Publications, Cambridge 0167-9430/88/$02.00
-
AUGUST 1988 [Vol. 6]
vided a forum for presenting results and exchanging ideas. Although fuel bioethanol still appeared to be the main product, the current research activity in biological production of high-value chemicals (particularly biodegradable plastics) indicated that there is still considerable potential for producing higher value products from biomass. QUANG NGUYEN
Biotechnology and Chemistry Department, Forintek Canada Corp., 800 Montreal Road, Ottawa, Ontario KIG 3Z5, Canada. []
[]
[]
The agenda stressed the applications and benefits of agricultural biotechnology, the importance of research, and the regulatory issues related to the release of genetically engineered organisms. A media panel provided delegates with a wealth of 'dos and don'ts' on h o w to handle the press. Orion Samuelson, host of a widely aired Chicago area farm news show, made it clear that the public relates to agriculture in a way very different from most of those who are familiar with biotechnology. The three most common questions he gets from his listeners, he said, are: • Why spend on research w h e n we produce too much food already? • Why pay farmers to grow what we don't need? • Why are people hungry while there is a surplus of food? None of these questions exclusively involves biotechnology, yet biotechnology is becoming the trigger that precipitates the questions. The conference program continued with a number of panels dedicated to applications of biotechnology ranging from food technology to plant science and animal science. A regulatory panel was well attended and generated animated discussion about how much regulation is needed, whether Congress needs to act and what the state's role should be. On the policy panel, Fred Smith of the Competitive Enterprise Institute presented a refreshing perspective in opposition to the position of Jack
ing of the requirements for substrate binding and catalysis is essential to improve the hydrolytic rate of enzymes. Using site-directed mutegenesis, modified cellulase enzyme complexes have been constructed that have higher hydrolytic activity than the native forms. Within the cellulase complex, synergism between cellobiohydrolase and endoglucanase is independent of their ratio in a crude mixture but is dependent on the level of saturation of substrate with enzyme (J. Woodward, Oak Ridge National Laboratory). Utilization of xylan (which is the major component of hemicellulose in hardwood) and lignin is of vital economic importance for all biological conversion of wood. Microbial conversion of hemicellulose hydrolysates from steam-treated birch w o o d to single cell protein, ethanol and xylonic acid has been successful only at dilute concentrations because of the inhibitory effect on the microorganisms of degradation products formed during the pretreatment (J. Buchert, VTT Biotechical Laboratory, Finland). Aromatic aldehyde oxidase from Streptomyces viridosporus was identified as a suitable enzyme for lignin biotransformation (D. L. Crawford and L. A. Deobald, University of Idaho). Perhaps the most commercially significant research in biological waste treatment is the in-situ treatment of contaminated underground petroleum products. The factors having major impact on treatment methods are the characteristicg of the soil and microorganisms at the contaminated site and the ability to circulate aerated nutrient solutions effectively (A. W. Bourquin, Ecova Corp.).
presentations dealt with continuous bioreactors. Among the more common designs is the immobilizedbiocatalyst, fluidized-bed reactor which generally gives high conversion rates at relatively low biocatalyst make-up requirements. An example is the fermentor used in the conversion of dextrose to ethanol and carbon dioxide - a columnar, threephase, fluidized-bed reactor packed with immobilized Z. mobilis (B. H. Davison, Oak Ridge National Laboratory). It was suggested that process economic evaluation using computer simulation should be conducted in parallel with laboratory research, especially for complex processes such as the bioconversion of w o o d to alcohols (N. D. Hinman, Solar Energy Research Institute; Q. Nguyen, Forintek Canada Corp.). This should help researchers focus their objectives more effectively. For example, in a fermentation process, the productivity does not have as much of an impact on the overall production cost as do product yield and product concentration. This brought up the familiar issue of the need for cooperation between engineers and microbiologists to improve the chances of success in the development of economically viable processes. Another old theme concerned bioprocessing of commodity chemicals as a potential alternative solution for improving the competitiveness of the US chemical industry (via new products, and improved process economics) and for securing feedstocks should there be a disruption in imported oil supply. Ethanol was identified as the most important feedstock because its derivatives could account for a third of all synthetic organic chemicals. However, further research is required to overcome the technical constraints (slow conversion rate, low product yield and concentration, sterile environment) which currently make biomass commodity chemicals uneconomical.
Bioengineering
Biodegradable plastics
Process economic evaluation and bioreactor design were among the predominant themes of the 'Bioengineering Research' session. Several
The 'Biological Production of Materials' session provided several interesting papers on biodegradable plastics. Environmental concerns
Something old, something n e w Biomass conversion is, perhaps, one of the less glamorous parts of biotechnology. Nevertheless, in terms of volume of research work and diversity of approach, it is one of the biggest. Many of its various themes received an airing recently in Gatlinburg, Tennessee*.
Lignocellulose processing In the area of thermal and chemical processing of lignocellulosic materials two major processing apprgaches were presented: acid hydrolysis and thermochemical pretreatment for subsequent enzymatic hydrolysis. The traditional two-stage sulfuric acid hydrolysis is still being improved with emphasis on recycling of acid and improved reactor design. It was reported that sulfuric acid recovery by electrodialysis from wood sugar hydrolysates is technically feasible (I. Goldstein, North Carolina State University). Continuous plug flow reactors and semi-batch percolation reactors are employed to produce high sugar concentrations in the hydrolysates (P. Bergeron, Solar Energy Research Institute, Golden). Thermochemical rather than enzymatic pretreatment is still the choice of many researchers: high temperature steam pretreatment with and without acid catalyst (G. D. McGinnis, Mississippi State University; W. Schwald, Forintek Canada Corp.); dilute acid prehydrolysis (A. O. Converse, Dartmouth College, Hanover; R. Torget, Solar Energy Research Institute); and pretreatment with organic solvent (H. L. Chum, Solar Energy Research Institute).
Applied biology The symposium section on applied biology covered a wide spectrum of research. According to S. Shoemaker (Genencor Inc.), a better understand*Tenth Symposium on Biotechnology for Fuels and Chemicals, Gatlinburg, USA; 16-20 May 1988.
© 1988, Elsevier Publications, Cambridge
0167 -9430/88/$02.00
TIBTECH
have forced several US cities and states to restrict the use of nonbiodegradable plastic for packaging. Other states are expected to take similar action. This has created a lot of research interest in biodegradable plastics as the potential market is enormous. Unlike the elusive fuel bioethanol market which must compete with gasoline, methanol and ethanol produced from ethylene, biodegradable plastics may have a market niche. Of some 'biodegradable' plastics currently on the market, only the filler (starch or cellulose) and []
[]
the plasticizers are biodegradable. Blending poly(lactic acid) (which can be produced from starch or hardwood hemicellulose) with thermoplastics such as polystyrene, polyethylene and polypropylene will impart biodegradability while preserving mechanical and thermal properties (R. Narayan, Purdue University). Feedstocks for biodegradable plastics can also be produced via microbial oxygenation of aromatics (D. W. Ribbons, hnperial College University of London; D.R. Lloyd, ICI-America). The symposium successfully pro-
[]
[]
[]
[]
[]
[]
[]
Biotechnology in agriculture: a worldwide upheaval Without food, m a n k i n d has little use for medicine or industry. Agriculture, the oldest biotechnology, is therefore also the most fundamental to our well-being. The application of modern methods of biotechnology represents just the latest step in the march of technology in agriculture. But it coincides with a growing public awareness of the disadvantages that have accompanied previous progress - the environmental, economic and ethical problems that result from intensive farming in developed countries. There is a growing scientific awareness that biotechnology has applications in farming in the developing countries. In the next few pages, Allen Dines' snapshot of public feeling in the US and Joske Bunders' appraisal of appropriate agricultural biotechnology form a r~sum6 of the changing climate in farming. For at least the last four years, the public's opinion of biotechnology has consumed tremendous energy among those in the industry and the scientific community as well as those who follow developments in the field. In the area of agricultural biotechnology, public attention has focused principally on the issue of the potential environmental hazards of field testing genetically engineered organisms. If the impression of public opinion expressed at the recent US Department of Agriculture (USDA) conference on Agricultural Biotechnology and the Public* is any indication, we may soon see a change in this focus to broader issues of *USDA Conference on Agricultural Biotechnology and The Public, Minneapolis, USA; 17-18 May 1988.
social and economic impacts of biotechnology on the farm and on our food production system. In the words of the USDA program description, the conference covered 'the explosive fusion ofbiotechnology with farming and what it means to the public'. The department assembled a broad and balanced program that provided those attending the conference with a diverse selection of views on what agricultural biotechnology can and cannot do, as well as what it should or should not be doing. Participants were largely a mixture of the biotechnology 'regulars' (company and agency people who are always in attendance at these events) and new participants from state government, the media and public interest groups seeking to learn about biotechnology.
(~ 1988, Elsevier Publications, Cambridge 0167-9430/88/$02.00
-
AUGUST 1988 [Vol. 6]
vided a forum for presenting results and exchanging ideas. Although fuel bioethanol still appeared to be the main product, the current research activity in biological production of high-value chemicals (particularly biodegradable plastics) indicated that there is still considerable potential for producing higher value products from biomass. QUANG NGUYEN
Biotechnology and Chemistry Department, Forintek Canada Corp., 800 Montreal Road, Ottawa, Ontario KIG 3Z5, Canada. []
[]
[]
The agenda stressed the applications and benefits of agricultural biotechnology, the importance of research, and the regulatory issues related to the release of genetically engineered organisms. A media panel provided delegates with a wealth of 'dos and don'ts' on h o w to handle the press. Orion Samuelson, host of a widely aired Chicago area farm news show, made it clear that the public relates to agriculture in a way very different from most of those who are familiar with biotechnology. The three most common questions he gets from his listeners, he said, are: • Why spend on research w h e n we produce too much food already? • Why pay farmers to grow what we don't need? • Why are people hungry while there is a surplus of food? None of these questions exclusively involves biotechnology, yet biotechnology is becoming the trigger that precipitates the questions. The conference program continued with a number of panels dedicated to applications of biotechnology ranging from food technology to plant science and animal science. A regulatory panel was well attended and generated animated discussion about how much regulation is needed, whether Congress needs to act and what the state's role should be. On the policy panel, Fred Smith of the Competitive Enterprise Institute presented a refreshing perspective in opposition to the position of Jack