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农业生物质能生产糖和乙醇过程中所使用的超强工业酶和微生物-学养殖技术和种植技术,了解种植业和养殖业前景,就到

时间:2019-08-01来源:景德镇新闻网 -[收藏本文]

项目来源 : 美国 
项目名称 : 农业生物质能生产糖和乙醇过程中所使用的超强工业酶和微生物 
承担机构 : 
项目编号 : 3620-41000-118-00 
起止时间 : 2004.8-2009.8 
项目成员 : Bruce S Dien 
联系方式 :
Fermentation Biotechnology Research
Chemical Engineer
Bruce dot Dien at ars dot usda dot gov
Phone: (309) 681-6270
Fax: (309) 681-6427
Room 3300
1815 N UNIVERSITY ST
PEORIA, IL, 61604-3999 
资助机构 : 美国农业部 
项目简介 :
目标:
按照现代预处理方式,通过利用新的酶和生物催化技术来设计更好的将草本生物质转换为乙醇的加工过程。通过发酵,评估将糖生物质能源转换为氢气的潜质。
方法:
利用低废物预处理和新型酶制剂,将草本生物原料转化为发酵糖的混合物;利用专为生物糖生产乙醇过程中所使用的重组微生物来对这些糖混合物进行发酵。这种做法具体步骤包括: (1)与植物育种者进行合作,开发特别适合于低化学品使用,轻度预处理的品种;(2)利用高度活跃厌氧真菌表达出的基因来创造新的酶基因;(3)制定bioabatement方法来去除受发酵干扰的有机化学品,从而增加了回收生物质糖的可发酵性;(4)利用工程革兰氏阳性菌有选择性地生产乙醇;该集团成员在工业发酵方面有着悠久的使用历史;(5)筛选和评价制氢细菌在生物质原料加工为氢气过程中的能力。BSL-1 and Risk Group RG1 recertified April 17, 2008. 
研究进展 :
2005 Annual Report
1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? What does it matter?
U.S. fuel ethanol production in 2004 exceeded 3.1 billion gallons. Most of this ethanol was produced from over 1 billion bushels of corn. Grain ethanol is expected to grow until it meets 4-5% of our automotive fuel needs. Expanding fuel ethanol production further to meet 10-15% or more of our fuel needs will require developing alternative fibrous feedstocks, such as agricultural residues and herbaceous energy crops. Such conversions are currently possible but are cost prohibitive. This is because agricultural material is made of many different polymers that must first be broken down into simple sugars that microorganisms can then use for the formation of products possessing higher value. Furthermore, a major technical hurdle to converting biomass to ethanol is developing an appropriate microorganism for the fermentation of mixed sugars. Our overall objective is to develop efficient global processes for converting crop cellulose and hemicellulose to ethanol and develop high-value co-products that will substitute for petrochemical derived industrial products.
This project directly addresses the Ethanol Component of National Program 307. Technologies are needed to reduce the cost of producing ethanol from corn and biomass. The lack of cost effective enzyme preparations for saccharifying biomass and industrially robust microorganisms for their conversion to bioethanol have been identified as the two most significant technical restraints to developing a domestic lignocellulose ethanol industry. This project also addresses Quality and Utilization of Agricultural Products, National Program 306. Specifically, this project addresses Component 2, New Processes, New Uses, and Value-Added Foods and Biobased Products. Specific areas addressed are Problem Areas 2a (New Product Technology), 2b (New Uses for Agricultural By-Products), and 2c (New and Improved Processes and Feedstocks). These areas will be addressed by developing new products from unutilized and underutilized agricultural residues via fermentation and biocatalytic processes.
The customer base for this renewable biofuel and coproduct research is international in scope and covers farmers, commodity groups, industry groups such as enzyme producers, grain processing companies, fermentation industry, etc., and scientists with other government agencies, universities, and private industry.
2.List the milestones (indicators of progress) from your Project Plan.
Major milestones are broken down by objective number and year of completion.
FY 2005 1.2 Test effect of harvest maturity. 1.2 Develop screening assay for ethanol yield. 3.1 Synthetic pdc gene w/Gram+ signals and vectors. 3.2 Isolate Klebsiella oxytoca mutants. 3.2 Evaluate Lactobacillus for xylose fermentation. 4.1 Bioabatement and Escherichia coli/yeast simultaneous saccharification and fermentation (SSF). 4.2 Verify cloned genes function in furoic acid growth.
FY 2006 1.1 Evaluate pretreated corn fiber. 2.1 Screen enzymes for biomass hydrolysis. 3.2 Characterize xylose metabolism for Lactobacillus. 3.2 Decision point for Klebsiella oxytoca and Lactobacillus. 4.1 Evaluate other strains for inhibitor removal. 4.1 Clone glucokinase gene and construct knockout. 4.2 LCMS to detect pathway intermediates.
FY 2007 1.2 Relate forage quality and ethanol yield. 2.3 Develop hosts for enzyme production. 3.1 Select alternate host organisms.
FY 2008 1.2 Develop new pretreatments. 1.2 Test hemicellulases. 2.2 Isolate candidate novel enzyme genes. 3.1 Add adh gene to Pdc-expressing organisms. 3.2 Introduce and stabilize further genetic changes. 4.1 Construct glucose non-metabolizing mutant. 4.2 Enzyme assays and synthesis of CoA compounds. 4.2 Express genes in Escherichia coli and Pseudomonas putida.
FY 2009 1.2 Integrate pretreatments, enzymes, and microbes. 2.3 Protein engineering of selected enzymes. 2.4 Evaluate engineered enzyme mixtures. 3.1 Measure Pdc activity and fermentation products. 3.1 Begin inactivating chromosomal metabolic genes. 4.1 Evaluate mutant function in bioabatement. 4.2 Structure-function studies for bioabatement.
4a.What was the single most significant accomplishment this past year?
DEVELOPING AN ALTERNATE CROP FOR FUEL ETHANOL PRODUCTION. Field pea production in northern U.S. is growing, and producers are looking towards expanding this market. Field peas are high in starch and, as such, represent a potential ethanol feedstock. We developed processes for dry fractionating field peas into enriched protein and starch streams and fermenting the pea starch to ethanol. Ethanol yields from fermenting peas were comparable to that of corn (on a starch basis), and the enriched protein stream was similar in protein content to high-protein soy meal, with a well balanced amino acid profile. Farmers and ethanol producers should directly benefit from this alternate feedstock, and we have been working with North Dakota Dry Pea and Lentil Association to inform ethanol producers situated in areas where field peas are cultivated.
4b.List other significant accomplishments, if any.
IMPROVED ENZYME PRODUCING FUNGI. The carbohydrates available for fermentation to ethanol that are typically found in biomass include cellulose and hemicellulose. Enzyme technology for converting hemicellulose (e.g., xylanase and othe杭州好的癫痫中医院rs) to fermentable sugars has lagged behind that for converting cellulose (i.e., cellulase) to glucose. We have addressed this problem by expressing a highly active xylanase protein in Trichoderma reesei, an industrial enzyme producing fungus. The engineered strain produced elevated yields of xylanase. This strain will be of interest to biotechnology companies marketing or researching enzymes for application to the biomass conversion and animal feed markets.
IMPROVED ENERGY CROPS FOR ETHANOL PRODUCTION. Herbaceous biomass from grasses is a potential feedstock for ethanol production. Many of these potential grass crops have been long used as animal forages, and research in this area indicates that harvest maturity is an important factor in deciding upon conversion efficiency. No one has looked at the effect of maturity on herbaceous grasses for ethanol conversion. We tested three grasses at different maturities for their glucose yields, an indirect measure of ethanol yields. The results showed that maturity was an important factor and that high glucose recoveries were measured for younger and middle maturity harvested biomass compared to those from older plants. This important result will be of great interest to plant breeders working in this area and eventually farmers looking to develop energy crops.
4c.List any significant activities that support special target populations.
None.
5.Describe the major accomplishments over the life of the project, including their predicted or actual impact.
This research program is a continuation of a previous project (3620-41000-084-00D) and, as part of that project, process and metabolic engineering technologies were developed that expand biofuel feedstocks and add value to agricultural wastes. Development of new and more active biomass hydrolyzing enzymes, along with robust genetically engineered microbes capable of fermenting multiple sugars, are recognized as major technical breakthroughs for the economic conversion of biomass to fuel ethanol and chemical feedstocks that can be used in a variety of renewable products. Specific accomplishments have included: Development of novel ethanologenic Escherichia coli strains that selectively convert sugars to ethanol or lactic acid at near to theoretical yields, discovery of a fungal microorganism that is adapted for removing organic by-products from biomass derived hydrolysates that retard fermentation, and the isolation and expression of a novel ferulic esterase enzyme that will enhance the action of cellulases for saccharification of biomass.
In this first year of the project, technology has been developed for converting field peas to fuel ethanol, production of novel xylanase enzymes, and increasing the efficiency of herbaceous energy crops to ethanol. The field pea work has potential as an alternative crop for ethanol production because it is grown in regions that have ethanol fermentation facilities, and yields of peas are increasing. A variety of enzymes useful for hydrolyzing biomass has been identified, characterized, and produced in transgenetic hosts. Technology from this project has already begun to be transferred to processing laboratories for inclusion into their research either directly or through our cooperation in the Midwest Consortium for Biobased Products and Bioenergy. Finally, the research on energy crops has been communicated to our collaborators, and we are in the process of extending this work with the goal of breeding superior yielding cultivars for ethanol production.
6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Results from our research have been transferred to academic and ARS researchers as well as industrial groups. Results from the field pea experiments have been communicated to an appropriate commodity group and commercial ethanol producers. Results from work on producing hydrolytic enzymes have been used by academic and government laboratories to further their own research into fiber utilization and its conversion to chemicals. The enzymes are also being used to develop processes for converting Distillers' Dry Grains with Solubles (DDGS) to ethanol by a multi-partner collaborative research group consisting of four universities and three federal laboratories. Members of this group were recently the recipient of a Federal Research Biomass Directed Grant from the Department of Energy. A commercial enzyme producer has also shown interest in possibly marketing an esterase developed by this group. Research on crop maturity and ethanol production has been used by several federal laboratories with expertise in plant breeding to aid in planning future plant breeding experiments. The work has also resulted in a set of biomass calibration standards that has generated considerable interest in those researching energy crops and has already been requested by one federal and two university research groups.
This research program is a follow up of a previous project (3620-41000-084-00D). Recombinant strains developed for ethanol and lactic acid fermentations from that effort continue to be requested by research groups. Groups that have requested these strains include Federal, industrial, and university laboratories.
7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
Anonymous. 2005. Enzymes generate sugars from corn fiber. Industrial Bioprocessing: Technical Insights. Frost and Sullivan. 27:7, p. 3.
2006 Annual Report
1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? Why does it matter?
U.S. fuel ethanol production in 2005 exceeded 4 billion gallons. Most of this ethanol was produced from over 1.5 billion bushels of corn. Grain ethanol is expected to grow until it meets 4-5% of our automotive fuel needs. Expanding fuel ethanol production further to meet 10-15% or more of our fuel needs will require developing alternative fibrous feedstocks, such as agricultural residues and herbaceous energy crops. Such conversions are cur黄冈羊羔疯治好要多少钱rently possible but are cost prohibitive. This is because agricultural material is made of many different polymers that must first be broken down into simple sugars that microorganisms can then use for the formation of products possessing higher value. Furthermore, a major technical hurdle to converting biomass to ethanol is developing an appropriate microorganism for the fermentation of mixed sugars. Our overall objective is to develop efficient global processes for converting crop cellulose and hemicellulose to ethanol and develop high-value co-products that will substitute for petrochemical derived industrial products.
This project directly addresses the Ethanol Component of National Program 307. Technologies are needed to reduce the cost of producing ethanol from corn and biomass. The lack of cost effective enzyme preparations for saccharifying biomass and industrially robust microorganisms for their conversion to bioethanol have been identified as the two most significant technical restraints to developing a domestic lignocellulose ethanol industry. This project also addresses Quality and Utilization of Agricultural Products, National Program 306. Specifically, this project addresses Component 2, New Processes, New Uses, and Value-Added Foods and Biobased Products. Specific areas addressed are Problem Areas 2a (New Product Technology), 2b (New Uses for Agricultural By-Products), and 2c (New and Improved Processes and Feedstocks). These areas will be addressed by developing new products from unutilized and underutilized agricultural residues via fermentation and biocatalytic processes.
The customer base for this renewable biofuel and coproduct research is international in scope and covers farmers, commodity groups, industry groups such as enzyme producers, grain processing companies, fermentation industry, etc., and scientists with other government agencies, universities, and private industry.
2.List by year the currently approved milestones (indicators of research progress)
FY 2005 1.2 Test effect of harvest maturity. 1.2 Develop screening assay for ethanol yield. 3.1 Synthetic pdc gene w/Gram+ signals and vectors. 3.2 Isolate Klebsiella oxytoca mutants. 3.2 Evaluate Lactobacillus for xylose fermentation. 4.1 Bioabatement and Escherichia coli/yeast simultaneous saccharification and fermentation (SSF). 4.2 Verify cloned genes function in furoic acid growth.
FY 2006 1.1 Evaluate pretreated corn fiber. 2.1 Screen enzymes for biomass hydrolysis. 3.2 Characterize xylose metabolism for Lactobacillus. 3.2 Decision point for Klebsiella oxytoca and Lactobacillus. 4.1 Evaluate other strains for inhibitor removal. 4.1 Clone glucokinase gene and construct knockout. 4.2 Characterize furfural degradation pathway.
FY 2007 1.2 Relate forage quality and ethanol yield. 2.3 Develop hosts for enzyme production. 3.1 Select alternate host organisms.
FY 2008 1.2 Develop new pretreatments. 1.2 Test hemicellulases. 2.2 Isolate candidate novel enzyme genes. 3.1 Add adh gene to Pdc-expressing organisms. 3.2 Introduce and stabilize further genetic changes. 4.1 Construct glucose non-metabolizing mutant. 4.2 Enzyme assays and synthesis of CoA compounds. 4.2 Express genes in Escherichia coli and Pseudomonas putida.
FY 2009 1.2 Integrate pretreatments, enzymes, and microbes. 2.3 Protein engineering of selected enzymes. 2.4 Evaluate engineered enzyme mixtures. 3.1 Measure Pdc activity and fermentation products. 3.1 Begin inactivating chromosomal metabolic genes. 4.1 Evaluate mutant function in bioabatement. 4.2 Structure-function studies for bioabatement.
4a.List the single most significant research accomplishment during FY 2006.
DEVELOPING A NEW EXPRESSION SYSTEM FOR PRODUCING HYDROLYTIC ENZYMES. This directly contributes to increasing process efficiencies for converting lignocellulosic biomass to ethanol as outlined in the ethanol component of National Program 307. Anaerobic fungi produce high active enzymes for lignocellulose degradation but they do not produce these enzymes in high yields. To capture the advantages of these enzymes, one will need to genetically engineer the genes coding for the enzymes into commonly used production hosts such as Trichoderma reesei and Aspergillus niger. We have successfully over-expressed the Orpinomyces xylanase A gene in T. reesei, and the heterologous xylanase is secreted into culture medium under cellulase production conditions. The engineered T. reesei strain produces high levels of xylanases in addition to its own cellulases, and the enzyme should enhance the lignocellulose conversion into fermentable sugars.
4b.List other significant research accomplishment(s), if any.
NOVEL ENZYME FOR RELEASING SUGARS FROM BIOMASS. This also directly contributes to increasing process efficiencies for converting lignocellulosic biomass to ethanol as outlined in the ethanol component of National Program 307. Xylose is the second most common sugar present in biomass after glucose. Sources of beta-xylosidase are needed for converting xylan to xylose for subsequent bioconversion to ethanol. We determined that the beta-xylosidase from Selenomonas ruminantium is the most catalytically efficient enzyme known (at least 15-fold better than those reported in the literature) for catalyzing the hydrolysis of xylooligosaccharides to xylose and has good properties of temperature and pH stability. Additionally, the enzyme can be efficiently produced in Escherichia coli (>4 g enzyme/liter). These properties place the enzyme at the forefront for development as a saccharification catalyst. Details of the enzyme mechanism and binding of substrates and inhibitors provide new insights that apply to other glycohydrolases.
IMPROVED ENZYMES FOR CONVERTING CORN FIBER TO FERMENTABLE SUGARS. This also directly contributes to increasing process efficiencies for converting lignocellulosic biomass to ethanol as outlined in the ethanol component of National Program 307. Corn fiber, a low-value co-product of corn wet milling, is a potential feedstock for ethanol production. Treating corn fiber with liquid hot-water is one proposed method for preparing the carbohydrates for fermentation. Liquid hot water (LHW) treatment breaks down most of the carbohydrates to oligomers, which are then converted to monosaccharides by treating with hydrolytic enzymes. Unfortunately, these oligomers are too chemically complex for c湖北小儿癫痫的好医院ommercial enzymes to completely digest. So, we developed custom enzyme preparations – prepared by growing fungi on LHW treated corn fiber - and demonstrated arabinose, glucose, and xylose yields of 80%, 100%, and 80%, respectively. This technology was developed as part of a current collaboration with Purdue University and Aventine Renewable Energy to demonstrate Purdue’s LHW technology at one of Aventine’s ethanol facilities.
4c.List significant activities that support special target populations.
None.
5.Describe the major accomplishments to date and their predicted or actual impact.
Research accomplishments are directed towards increasing the economic competitiveness for converting lignocellulose to biomass as outlined in the ethanol component of National Program 307. Development of new and more active biomass hydrolyzing enzymes, along with robust genetically engineered microbes capable of fermenting multiple sugars, are recognized as major technical breakthroughs for the economic conversion of biomass to fuel ethanol and chemical feedstocks that can be used in a variety of renewable products. Specific accomplishments have included: Development of novel ethanologenic Escherichia coli strains that selectively convert sugars to ethanol or lactic acid at near to theoretical yields, discovery of a fungal microorganism that is adapted for removing organic by-products from biomass derived hydrolysates that retard fermentation, and the isolation and expression of a novel ferulic esterase enzyme that will enhance the action of cellulases for saccharification of biomass.
In the first two years of this project, technology has been developed for converting field peas to fuel ethanol, production of novel xylanase enzymes, and increasing the efficiency of herbaceous energy crops to ethanol. The field pea work has potential as an alternative crop for ethanol production because it is grown in regions that have ethanol fermentation facilities, and yields of peas are increasing. Information on this technology has been shared with the Pea and Lentil Association and has been expanded to investigate corn/pea mixtures. The technology has also been widely published in U.S. and Canadian trade journals and has led to numerous discussions with potential users. A new beta-xylosidase has been characterized that is significantly improved compared to currently available enzymes. Discussions are currently underway to have DuPont evaluate the enzyme as part of their ongoing commercial interests in biomass processing. Finally, a medium throughput ethanol assay for ranking herbaceous biomass in terms of yields has been developed. This has led to many requests within and outside of ARS to evaluate samples. This assay is expected to lead to the first effort to develop energy crop cultivars selected for increased ethanol yield.
6.What science and/or technologies have been transferred and to whom? When is the science and/or technology likely to become available to the end-user (industry, farmer, other scientists)? What are the constraints, if known, to the adoption and durability of the technology products?
Results from our research have been transferred to academic and ARS researchers as well as industrial groups. Results from the field pea experiments have been communicated to an appropriate commodity group and commercial ethanol producers. Results from work on producing hydrolytic enzymes have been used by academic and government laboratories to further their own research into fiber utilization and its conversion to chemicals. The enzymes are also being used to develop processes for converting Distillers' Dry Grains with Solubles (DDGS) to ethanol by a multi-partner collaborative research group consisting of four universities and three federal laboratories. Members of this group were recently the recipient of a Federal Research Biomass Directed Grant from the Department of Energy. An industrial partner has indicated interest in evaluating our beta-xylosidase as part of their ongoing program in biomass conversion. Research on crop maturity and ethanol production has been used by several federal laboratories with expertise in plant breeding to aid in planning future plant breeding experiments. The work has also resulted in a set of biomass calibration standards that has generated considerable interest in those researching energy crops and has already been requested by two federal and three university research groups.
This research program is a follow up of a previous project (3620-41000-084-00D). Recombinant strains developed for ethanol and lactic acid fermentations from that effort continue to be requested by research groups. Groups that have requested these strains include Federal, industrial, and university laboratories.
7.List your most important publications in the popular press and presentations to organizations and articles written about your work. (NOTE: List your peer reviewed publications below).
Plant biofuels. Dec. 16, 2005. MicrobeWorld Radio Show. American Society for Microbiology and Fingerlakes Production Radio. Peas pose option for ethanol. April 13, 2006. Sean Pratt. Western Producer. p. 21. Pea starch a source of ethanol? April 25, 2006. Geoff Dale, Farmcentre.com. Fuel in the fridge. July/Sept. 2006. Agricultural Innovation. 15(3):9. Ethanol from pea starch. 2006. Industrial Bioprocessing. 28(5):7. NDDPLA collaborates with ARS in studying peas in ethanol. March 2006. Anonymous. NDDPLA Newsletter. Development of new biocatalysts for the conversion of lignocellulose to ethanol. M. Cotta. Presented at the Workshop on Sustainable Bioenergy: Focus on the Future of Biofuels and Chemicals. April 13-14, 2006. University of Illinois at Urbana-Champaign. Imagine-fuel alcohol from pea starch! March 28, 2006. Jan Suszkiw. ARS Magazine. This article by Jan Suszkiw was also reprinted or adapted by: Agriculture Industry Today, Alternate Energy Resource Network, Agnet (Food Safety Network, Univ. of Guelph), Agra-net.com, Agri-View, Alternate Energy Resource Network, American Vegetable Grower, Axcess News, Biofuels Journal, CommunityDispatch.com, Doane Agricultural Services, DomesticFuel.com, Environmental Observatory, FarmAssist.ca, Farmers National Company, Farms.com, FoodIngredients.com, High Plains/Midwest Ag Journal, John Deere Ag News, MidAmerica CropLife Association, Monsanto.com, Ohio Farm Bureau Federation, ScienceBlog北京癫痫中医医院.com, Statpub.com, The Bay Net (Maryland) News, The Soy Daily, TradingCharts.com.
2007 Annual Report
1a.Objectives (from AD-416)
Develop improved processes for converting herbaceous biomass to ethanol by incorporating new enzyme and biocatalyst technologies with modern pretreatment strategies. Evaluate potential for converting biomass derived sugars to hydrogen via fermentation.
1b.Approach (from AD-416)
Herbaceous biomass feedstocks will be converted to fermentable sugar mixtures using low-waste pretreatments and novel enzymatic preparations. The generated sugar mixtures will be fermented using recombinant microorganisms specifically engineered for producing ethanol from biomass sugars. Specific steps in this approach include: (1) working with plant breeders to develop cultivars especially suited for low-chemical usage, mild pretreatments, (2) generating new enzyme mixtures using genes recovered and over-expressed from highly active anaerobic fungi, (3) developing bioabatement methods for removing organic chemical that interfere with fermentation and, thereby, increasing the fermentability of the recovered biomass sugars, (4) engineering gram positive bacteria to selectively produce ethanol; members of this group have a long history of use in industrial fermentations, and (5) screen and evaluate hydrogen producing bacteria for capability to co-produce hydrogen from biomass feedstocks.
4.Accomplishments
SCREENING SWITCHGRASS CULTIVARS FOR ETHANOL YIELDS. Switchgrass has been viewed as one of the most promising candidates for an energy crop, but more efficient cultivars are needed for conversion to ethanol. Over 100 samples of switchgrass were pretreated and converted to ethanol by simultaneous saccharification and fermentation. Samples varied widely in environmental growth conditions and genetic traits. The results demonstrated a wide-spectrum in conversion yields for the different samples and validate the need for further plant breeding of energy crops. This data is currently being applied to develop a quick scanning near-infrared (NIR) model that will be used for breeding switchgrass cultivars for superior ethanol yield. This work applies directly to National Program 307, Bioenergy and Energy Alternatives, Component I and IV, Ethanol and Energy Crops, because it relates to conversion of biomass into ethanol and processing of energy crops.
DISCOVERY AND ISOLATION OF A GENE ENCODING FOR A NOVEL ENZYME ACTIVITY FOR BIOMASS DEGRADATION FROM TRICHODERMA REESEI. New enzymes are needed for breaking down plant cell walls for conversion to ethanol because current enzyme blends are not always effective. The fungus T. reesei is the most common source for commercial cellulases, and novel genes related to biomass conversion are extremely important for further improvement of industrial cellulases. The enzyme discovered is a glucuronic acid esterase; glucuronic acids are present in a wide variety of biomasses and an ability to remove them is expected to directly lower yields by interfering with the release of neutral sugars. This work applies directly to National Program 307, Bioenergy and Energy Alternatives, Component I, Ethanol, because it relates to conversion of biomass into ethanol.
THE BIFUNCTIONAL BETA-D-XYLOSIDASE/ALPHA-L-ARABINOFURANOSIDASE FROM SELENOMONAS RUMINANTIUM IS THE BEST CATALYST KNOWN (KCAT, KCAT/KM) FOR PROMOTING HYDROLYSIS OF 1,4-BETA-D-XYLOOLIGOSACCHARIDES, AND IT HAS POTENTIAL FOR USE IN SACCHARIFICATION PROCESSES. Highly active biomass conversion enzymes are required for economic and efficient saccharification of agricultural biomass. Active-site amino acid residues that are involved in substrate distortion and increasing enzyme activity have been identified. As well, active-site amino acid residues that are involved in preferring xylose glycosides over arabinose glycosides have been identified. Enzyme-inhibitor complexes that could be formed in saccharification processes have been demonstrated. This work applies directly to National Program 307, Bioenergy and Energy Alternatives, Component I, Ethanol, because it relates to conversion of biomass into ethanol.
IMPROVING FERMENTABILITY OF BIOMASS SUGARS. Inhibitors arising during conversion of biomass to sugars are impediments to fermentative production of ethanol. Over three dozen chemical by-products were detected in hydrolyzed corn and evaluated for removal by a biological treatment system. The fermentability of hydrolysates was improved by biological abatement, due to removal of a number of inhibitory compounds present in acid-pretreated corn stover. This work is being expanded to include an alkaline-pretreated feedstock, which has a different array of inhibitory compounds. The inhibitor abatement methods remove side-products of pretreatment and can greatly enhance the yield and rate of production for biofuels. This work applies directly to National Program 307, Bioenergy and Energy Alternatives, Component I, Ethanol, because it relates to conversion of biomass into ethanol.
ISOLATION OF HYDROLYTIC ENZYMES FROM RHIZOPUS ORYZAE SPECIES. The filamentous fungus Rhizopus oryzae contains a large and diverse complement of biomass degrading enzymes that are of interest for improving the efficacy and efficiency of biomass degradation. Three unique previously unidentified glucoamylase genes (glucoamylase aids in the breakdown of starch) from two different Rhizopus strains were isolated, expressed, and initial biochemical characterization performed. Two of the enzymes were highly active, while the third enzyme is inactive, even though it is a truncated version of a previously isolated enzyme. Indepth biochemical characterization of the active enzymes is in progress with an eye toward the potential use of these enzymes as processing aids in biomass degradation. This work applies directly to National Program 307, Bioenergy and Energy Alternatives, Component I, Ethanol, because it relates to conversion of biomass into ethanol.
5.Significant Activities that Support Special Target Populations
None.
6.Technology Transfer
Number of new CRADAs and MTAs 7 Number of active CRADAs and MTAs 10 Number of patent granted 1 Number of non-peer reviewed presentations and proceedings 18 Number of newspaper articles and other presentations for non-science audiences 12