Search

Your search keyword '"Wyman, Charles E."' showing total 925 results
Start Over Author "Wyman, Charles E."

Refine your results

more »

more »

more »

more »
925 results on '"Wyman, Charles E."'

3. Impacts of cellulase deactivation at the moving air–liquid interface on cellulose conversions at low enzyme loadings

Author

Bhagia, Samarthya, Wyman, Charles E, and Kumar, Rajeev

Subjects
Biological Sciences, Industrial Biotechnology, Cellulose, Cellulase, Deactivation, Hydrolysis, Air-liquid interface, Gas-liquid interface, Air–liquid interface, Gas–liquid interface, Chemical Engineering, Biochemistry and cell biology, Industrial biotechnology
Abstract

BackgroundWe recently confirmed that the deactivation of T. reesei cellulases at the air-liquid interface reduces microcrystalline cellulose conversion at low enzyme loadings in shaken flasks. It is one of the main causes for lowering of cellulose conversions at low enzyme loadings. However, supplementing cellulases with small quantities of surface-active additives in shaken flasks can increase cellulose conversions at low enzyme loadings. It was also shown that cellulose conversions at low enzyme loadings can be increased in unshaken flasks if the reactions are carried for a longer time. This study further explores these recent findings to better understand the impact of air-liquid interfacial phenomena on enzymatic hydrolysis of cellulose contained in Avicel, Sigmacell, α-cellulose, cotton linters, and filter paper. The impacts of solids and enzyme loadings, supplementation with nonionic surfactant Tween 20 and xylanases, and application of different types of mixing and reactor designs on cellulose hydrolysis were also evaluated.ResultsAvicel cellulose conversions at high solid loading were more than doubled by minimizing loss of cellulases to the air-liquid interface. Maximum cellulose conversions were high for surface-active supplemented shaken flasks or unshaken flasks because of low cellulase deactivation at the air-liquid interface. The nonionic surfactant Tween 20 was unable to completely prevent cellulase deactivation in shaken flasks and only reduced cellulose conversions at unreasonably high concentrations.ConclusionsHigh dynamic interfacial areas created through baffles in reactor vessels, low volumes in high-capacity vessels, or high shaking speeds severely limited cellulose conversions at low enzyme loadings. Precipitation of cellulases due to aggregation at the air-liquid interface caused their continuous deactivation in shaken flasks and severely limited solubilization of cellulose.

Published
2019

4. CELF significantly reduces milling requirements and improves soaking effectiveness for maximum sugar recovery of Alamo switchgrass over dilute sulfuric acid pretreatment

Author

Patri, Abhishek S, McAlister, Laura, Cai, Charles M, Kumar, Rajeev, and Wyman, Charles E

Subjects
Biological Sciences, Industrial Biotechnology, Affordable and Clean Energy, Biomass, Pretreatment, Soaking, Enzymatic hydrolysis, Dilute acid, Tetrahydrofuran, Size reduction, Chemical Engineering, Biochemistry and cell biology, Industrial biotechnology
Abstract

BackgroundPretreatment is effective in reducing the natural recalcitrance of plant biomass so polysaccharides in cell walls can be accessed for conversion to sugars. Furthermore, lignocellulosic biomass must typically be reduced in size to increase the pretreatment effectiveness and realize high sugar yields. However, biomass size reduction is a very energy-intensive operation and contributes significantly to the overall capital cost.ResultsIn this study, the effect of particle size reduction and biomass presoaking on the deconstruction of Alamo switchgrass was examined prior to pretreatment by dilute sulfuric acid (DSA) and Co-solvent Enhanced Lignocellulosic Fractionation (CELF) at pretreatment conditions optimized for maximum sugar release by each pretreatment coupled with subsequent enzymatic hydrolysis. Sugar yields by enzymatic hydrolysis were measured over a range of enzyme loadings. In general, DSA successfully solubilized hemicellulose, while CELF removed nearly 80% of Klason lignin from switchgrass in addition to the majority of hemicellulose. Presoaking and particle size reduction did not have a significant impact on biomass compositions after pretreatment for both DSA and CELF. However, presoaking for 4 h slightly increased sugar yields by enzymatic hydrolysis of DSA-pretreated switchgrass compared to unsoaked samples, whereas sugar yields from enzymatic hydrolysis of CELF solids continued to increase substantially for up to 18 h of presoaking time. Of particular importance, DSA required particle size reduction by knife milling to

Published
2019

5. Correction to: Multiple levers for overcoming the recalcitrance of lignocellulosic biomass

Author

Holwerda, Evert K, Worthen, Robert S, Kothari, Ninad, Lasky, Ronald C, Davison, Brian H, Fu, Chunxiang, Wang, Zeng-Yu, Dixon, Richard A, Biswal, Ajaya K, Mohnen, Debra, Nelson, Richard S, Baxter, Holly L, Mazarei, Mitra, Stewart, C Neal, Muchero, Wellington, Tuskan, Gerald A, Cai, Charles M, Gjersing, Erica E, Davis, Mark F, Himmel, Michael E, Wyman, Charles E, Gilna, Paul, and Lynd, Lee R

Subjects
Biological Sciences, Industrial Biotechnology, Chemical Engineering, Biochemistry and cell biology, Industrial biotechnology
Abstract

[This corrects the article DOI: 10.1186/s13068-019-1353-7.].

Published
2019

12. Multiple levers for overcoming the recalcitrance of lignocellulosic biomass

Author

Holwerda, Evert K, Worthen, Robert S, Kothari, Ninad, Lasky, Ronald C, Davison, Brian H, Fu, Chunxiang, Wang, Zeng-Yu, Dixon, Richard A, Biswal, Ajaya K, Mohnen, Debra, Nelson, Richard S, Baxter, Holly L, Mazarei, Mitra, Stewart, C. Neal, Muchero, Wellington, Tuskan, Gerald A, Cai, Charles M, Gjersing, Erica E, Davis, Mark F, Himmel, Michael E, Wyman, Charles E, Gilna, Paul, and Lynd, Lee R

Subjects
CE-CERT
Published
2019

31. Undefined cellulase formulations hinder scientific reproducibility

Author

Himmel, Michael E, Abbas, Charles A, Baker, John O, Bayer, Edward A, Bomble, Yannick J, Brunecky, Roman, Chen, Xiaowen, Felby, Claus, Jeoh, Tina, Kumar, Rajeev, McCleary, Barry V, Pletschke, Brett I, Tucker, Melvin P, Wyman, Charles E, and Decker, Stephen R

Subjects
Biological Sciences, Industrial Biotechnology, Cellulase, Cellulose, Biofuels, Assays, Commercial cellulase formulations, Chemical Engineering, Biochemistry and cell biology, Industrial biotechnology
Abstract

In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparations may not be available. Therefore, being a critical tenet of science publishing, experimental reproducibility is endangered by the continued use of these undisclosed products. We propose the introduction of standard procedures and materials to produce specific and reproducible cellulase formulations. These formulations are to serve as yardsticks to measure improvements and performance of new cellulase formulations.

Published
2017

36. Economics and global warming potential of a commercial-scale delignifying biorefinery based on co-solvent enhanced lignocellulosic fractionation to produce alcohols, sustainable aviation fuels, and co-products from biomass

Author

Klein, Bruno Colling, primary, Scheidemantle, Brent, additional, Hanes, Rebecca J., additional, Bartling, Andrew W., additional, Grundl, Nicholas J., additional, Clark, Robin J., additional, Biddy, Mary J., additional, Tao, Ling, additional, Trinh, Cong T., additional, Guss, Adam M., additional, Wyman, Charles E., additional, Ragauskas, Arthur J., additional, Webb, Erin G., additional, Davison, Brian H., additional, and Cai, Charles M., additional

Published
2024
Full Text
View/download PDF

38. Cellulosic ethanol: status and innovation

Author

Lynd, Lee R, Liang, Xiaoyu, Biddy, Mary J, Allee, Andrew, Cai, Hao, Foust, Thomas, Himmel, Michael E, Laser, Mark S, Wang, Michael, and Wyman, Charles E

Published
2017

49. Next-generation ammonia pretreatment enhances cellulosic biofuel production

Author

da Costa Sousa, Leonardo, Jin, Mingjie, Chundawat, Shishir P. S, Bokade, Vijay, Tang, Xiaoyu, Azarpira, Ali, Lu, Fachuang, Avci, Utku, Humpula, James, Uppugundla, Nirmal, Gunawan, Christa, Pattathil, Sivakumar, Cheh, Albert M, Kothari, Ninad, Kumar, Rajeev, Ralph, John, Hahn, Michael G, Wyman, Charles E, Singh, Seema, Simmons, Blake A, Dale, Bruce E, and Balan, Venkatesh

Published
2016

Catalog

Books, media, physical & digital resources
See catalog results