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Full-Text Articles in Biotechnology

Structure-Function Investigation Of Proteins Involved In Cellulose Biosynthesis By Escherichia Coli, Thomas Brenner Jan 2017

Structure-Function Investigation Of Proteins Involved In Cellulose Biosynthesis By Escherichia Coli, Thomas Brenner

Theses and Dissertations (Comprehensive)

Bacteria thrive within multicellular communities called biofilms consisting of a self-produced matrix. Biofilm matrices improve bacterial adherence to surfaces while creating a barrier from host immune responses, disinfectants, antibiotics and other environmental factors. Persistent colonization by the widely distributed pathogens, Escherichia coli and Salmonella spp., has been linked to production of biofilms composed of the exopolysaccharide cellulose. Cellulose-containing biofilms are also important to Acetobacter, Sarcina, Rhizobium and Agrobacterium species to form symbiotic and pathogenic interactions. In Enterobacteriaceae, two operons (bcsABZC and bcsEFG) are proposed to encode for proteins that form a cellulose biosynthetic complex that spans the …


Elimination Of Hydrogenase Active Site Assembly Blocks H2 Production And Increases Ethanol Yield In Clostridium Thermocellum, Ranjita Biswas, Tianyong Zheng, Daniel G. Olson, Lee R. Lynd, Adam M. Guss Feb 2015

Elimination Of Hydrogenase Active Site Assembly Blocks H2 Production And Increases Ethanol Yield In Clostridium Thermocellum, Ranjita Biswas, Tianyong Zheng, Daniel G. Olson, Lee R. Lynd, Adam M. Guss

Dartmouth Scholarship

Background: The native ability of Clostridium thermocellum to rapidly consume cellulose and produce ethanol makes it a leading candidate for a consolidated bioprocessing (CBP) biofuel production strategy. C. thermocellum also synthesizes lactate, formate, acetate, H2 , and amino acids that compete with ethanol production for carbon and electrons. Elimination of H2 production could redirect carbon flux towards ethanol production by making more electrons available for acetyl coenzyme A reduction to ethanol. Results: H2 production in C. thermocellum is encoded by four hydrogenases. Rather than delete each individually, we targeted hydrogenase maturase gene hydG, involved in converting the …


The Exometabolome Of Clostridium Thermocellum Reveals Overflow Metabolism At High Cellulose Loading, Evert K. Holwerda, Philip G. Thorne, Daniel G. Olson, Daniel Amador-Noguez, Nancy L. Engle, Timothy J. Tschaplinski, Johannes P. Van Dijken, Lee R. Lynd Oct 2014

The Exometabolome Of Clostridium Thermocellum Reveals Overflow Metabolism At High Cellulose Loading, Evert K. Holwerda, Philip G. Thorne, Daniel G. Olson, Daniel Amador-Noguez, Nancy L. Engle, Timothy J. Tschaplinski, Johannes P. Van Dijken, Lee R. Lynd

Dartmouth Scholarship

BackgroundClostridium thermocellum is a model thermophilic organism for the production of biofuels from lignocellulosic substrates. The majority of publications studying the physiology of this organism use substrate concentrations of ≤10 g/L. However, industrially relevant concentrations of substrate start at 100 g/L carbohydrate, which corresponds to approximately 150 g/L solids. To gain insight into the physiology of fermentation of high substrate concentrations, we studied the growth on, and utilization of high concentrations of crystalline cellulose varying from 50 to 100 g/L by C. thermocellum. .


Analyzing Environmental Microbes For Genomic Regions Promoting Ionic Liquid Tolerance In E. Coli, Ann Nguyen, Alison Richins, Thomas Rüegg, Steven Singer, Michael Thelen Aug 2012

Analyzing Environmental Microbes For Genomic Regions Promoting Ionic Liquid Tolerance In E. Coli, Ann Nguyen, Alison Richins, Thomas Rüegg, Steven Singer, Michael Thelen

STAR Program Research Presentations

Ionic liquids (ILs) are promising as solvents to increase the efficiency of biofuel production; however, ILs are toxic to microbes used in the fermentation of liquid fuels. To engineer IL resistant biofuel hosts, environmental bacteria were screened for tolerance, and these were used to create gene libraries to test in E. coli. Future characterization of these libraries using molecular techniques will be used to identify genes that contribute IL-tolerance to transformed microbes.


Quantitative Analysis Of Lignocellulosic Components Of Non-Treated And Steam Exploded Barley, Canola, Oat And Wheat Straw Using Fourier Transform Infrared Spectroscopy, P. K. Adapa, L. G. Schonenau, Thomas Canam, T. Dumonceaux Jan 2011

Quantitative Analysis Of Lignocellulosic Components Of Non-Treated And Steam Exploded Barley, Canola, Oat And Wheat Straw Using Fourier Transform Infrared Spectroscopy, P. K. Adapa, L. G. Schonenau, Thomas Canam, T. Dumonceaux

Thomas Canam

Rapid and cost effective quantification of lignocellulosic components (cellulose, hemicelluloses and lignin) of agricultural biomass (barley, canola, oat and wheat) is essential to determine the effect of various pre-treatments (such as steam explosion) on biomass used as feedstock for the biofuel industry. Fourier Transformed Infrared (FTIR) spectroscopy was considered as an option to achieve this objective. Regression equations having R2 values of 0.89, 0.99 and 0.98 were developed to predict the cellulose, hemicelluloses and lignin compounds of biomass, respectively. The average absolute difference in predicted and measured cellulose, hemicellulose and lignin in agricultural biomass was 7.5%, 2.5%, and 3.8%, respectively.


Quantitative Analysis Of Lignocellulosic Components Of Non-Treated And Steam Exploded Barley, Canola, Oat And Wheat Straw Using Fourier Transform Infrared Spectroscopy, P. Adapa, L. Schonenau, Thomas Canam, T. Dumonceaux Jan 2011

Quantitative Analysis Of Lignocellulosic Components Of Non-Treated And Steam Exploded Barley, Canola, Oat And Wheat Straw Using Fourier Transform Infrared Spectroscopy, P. Adapa, L. Schonenau, Thomas Canam, T. Dumonceaux

Faculty Research & Creative Activity

Rapid and cost effective quantification of lignocellulosic components (cellulose, hemicelluloses and lignin) of agricultural biomass (barley, canola, oat and wheat) is essential to determine the effect of various pre-treatments (such as steam explosion) on biomass used as feedstock for the biofuel industry. Fourier Transformed Infrared (FTIR) spectroscopy was considered as an option to achieve this objective. Regression equations having R2 values of 0.89, 0.99 and 0.98 were developed to predict the cellulose, hemicelluloses and lignin compounds of biomass, respectively. The average absolute difference in predicted and measured cellulose, hemicellulose and lignin in agricultural biomass was 7.5%, 2.5%, and 3.8%, respectively.


Quantitative Analysis Of Lignocellulosic Components Of Non-Treated And Steam Exploded Barley, Canola, Oat And Wheat Straw Using Fourier Transform Infrared Spectroscopy, P. K. Adapa, L. G. Schonenau, Thomas Canam, T. Dumonceaux Jan 2011

Quantitative Analysis Of Lignocellulosic Components Of Non-Treated And Steam Exploded Barley, Canola, Oat And Wheat Straw Using Fourier Transform Infrared Spectroscopy, P. K. Adapa, L. G. Schonenau, Thomas Canam, T. Dumonceaux

Faculty Research & Creative Activity

Rapid and cost effective quantification of lignocellulosic components (cellulose, hemicelluloses and lignin) of agricultural biomass (barley, canola, oat and wheat) is essential to determine the effect of various pre-treatments (such as steam explosion) on biomass used as feedstock for the biofuel industry. Fourier Transformed Infrared (FTIR) spectroscopy was considered as an option to achieve this objective. Regression equations having R2 values of 0.89, 0.99 and 0.98 were developed to predict the cellulose, hemicelluloses and lignin compounds of biomass, respectively. The average absolute difference in predicted and measured cellulose, hemicellulose and lignin in agricultural biomass was 7.5%, 2.5%, and 3.8%, respectively.


Over-Expression Of Udp-Glucose Pyrophosphorylase In Hybrid Poplar Affects Carbon Allocation, Heather D. Coleman, Thomas Canam, Kyu-Young Kang, David D. Ellis, Shawn D. Mansfield Jan 2007

Over-Expression Of Udp-Glucose Pyrophosphorylase In Hybrid Poplar Affects Carbon Allocation, Heather D. Coleman, Thomas Canam, Kyu-Young Kang, David D. Ellis, Shawn D. Mansfield

Thomas Canam

The effects of the over-expression of the Acetobacter xylinum UDP-glucose pyrophosphorylase (UGPase) under the control of the tandem repeat Cauliflower Mosaic Virus promoter (2335S) on plant metabolism and growth were investigated in hybrid poplar (Populus alba3grandidentata). Transcript levels, enzyme activity, growth parameters, leaf morphology, structural and soluble carbohydrates, and soluble metabolite levels were quantified in both transgenic and wild-type trees. Transgenic 2335S::UGPase poplar showed impaired growth rates, displaying reduced height growth and stem diameter. Morphologically, 2335S::UGPase trees had elongated axial shoots, and leaves that were substantially smaller in size when compared with wild-type trees at equivalent developmental stages. Biochemical analysis …


Over-Expression Of Udp-Glucose Pyrophosphorylase In Hybrid Poplar Affects Carbon Allocation, Heather Coleman, Thomas Canam, Kyu-Young Kang, David Ellis, Shawn Mansfield Jan 2007

Over-Expression Of Udp-Glucose Pyrophosphorylase In Hybrid Poplar Affects Carbon Allocation, Heather Coleman, Thomas Canam, Kyu-Young Kang, David Ellis, Shawn Mansfield

Faculty Research & Creative Activity

The effects of the over-expression of the Acetobacter xylinum UDP-glucose pyrophosphorylase (UGPase) under the control of the tandem repeat Cauliflower Mosaic Virus promoter (2335S) on plant metabolism and growth were investigated in hybrid poplar (Populus alba3grandidentata). Transcript levels, enzyme activity, growth parameters, leaf morphology, structural and soluble carbohydrates, and soluble metabolite levels were quantified in both transgenic and wild-type trees. Transgenic 2335S::UGPase poplar showed impaired growth rates, displaying reduced height growth and stem diameter. Morphologically, 2335S::UGPase trees had elongated axial shoots, and leaves that were substantially smaller in size when compared with wild-type trees at equivalent developmental stages. Biochemical analysis …


Over-Expression Of Udp-Glucose Pyrophosphorylase In Hybrid Poplar Affects Carbon Allocation, Heather D. Coleman, Thomas Canam, Kyu-Young Kang, David D. Ellis, Shawn D. Mansfield Jan 2007

Over-Expression Of Udp-Glucose Pyrophosphorylase In Hybrid Poplar Affects Carbon Allocation, Heather D. Coleman, Thomas Canam, Kyu-Young Kang, David D. Ellis, Shawn D. Mansfield

Faculty Research & Creative Activity

The effects of the over-expression of the Acetobacter xylinum UDP-glucose pyrophosphorylase (UGPase) under the control of the tandem repeat Cauliflower Mosaic Virus promoter (2335S) on plant metabolism and growth were investigated in hybrid poplar (Populus alba3grandidentata). Transcript levels, enzyme activity, growth parameters, leaf morphology, structural and soluble carbohydrates, and soluble metabolite levels were quantified in both transgenic and wild-type trees. Transgenic 2335S::UGPase poplar showed impaired growth rates, displaying reduced height growth and stem diameter. Morphologically, 2335S::UGPase trees had elongated axial shoots, and leaves that were substantially smaller in size when compared with wild-type trees at equivalent developmental stages. Biochemical analysis …