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Correlation Analysis Of Enzyme Activities And Deconstruction Of Ammonia-Pretreated Switchgrass By Bacterial-Fungal Communities, Abhiney Jain, H. Sandra Pelle, J. Michael Henson

H. Sandra Pelle

The mixed microbial communities that occur naturally on lignocellulosic feedstocks can provide feedstock-specific enzyme mixtures to saccharify lignocelluloses. Bacterial-fungal communities were enriched from switchgrass bales to deconstruct ammonia-pretreated switchgrass (DSG). Correlation analysis was carried out to elucidate the relationship between microbial decomposition of DSG by these communities, enzymatic activities produced and enzymatic saccharification of DSG using these enzyme mixtures. Results of the analysis showed that β glucosidase activities and xylosidase activities limited the extent of microbial deconstruction and enzymatic saccharification of DSG. The results also underlined the importance of ligninase activity for the enzymatic saccharification of pretreated lignocellulosic feedstock. The …

Strategies For The Production Of Cell Wall-Deconstructing Enzymes In Lignocellulosic Biomass And Their Utilization For Biofuel Production, Sang-Hyuck Park, Rebecca Garlock Ong, Mariam Sticklen

Rebecca Ong

Microbial cell wall-deconstructing enzymes are widely used in the food, wine, pulp and paper, textile, and detergent industries and will be heavily utilized by cellulosic biorefineries in the production of fuels and chemicals. Due to their ability to use freely available solar energy, genetically engineered bioenergy crops provide an attractive alternative to microbial bioreactors for the production of cell wall-deconstructing enzymes. This review article summarizes the efforts made within the last decade on the production of cell wall-deconstructing enzymes in planta for use in the deconstruction of lignocellulosic biomass. A number of strategies have been employed to increase enzyme yields …

Aqueous Processing Of Lignocellulosic Biomass To Advanced Biofuels | Biological Engineering, Usu College Of Engineering

College of Engineering News

An important current focus of research in biology, chemistry, engineering, agriculture, and environmental sciences is the development of clean technologies that utilize cellulosic biomass as a renewable resource to the largest extent possible in a biorefinery setting to produce sustainable liquid transportation fuels and chemicals. Of all sustainable resources, only biomass can be transformed into organic fuels and chemicals that can integrate well into our current transportation infrastructure with the inherent convenience, cost, and efficiency advantages of current fuels. Cellulosic biomass can be converted to fuels and chemicals through aqueous-phase processes involving carbohydrates-derived and lignin-derived reactive intermediates deconstructed from these …

Correlation Analysis Of Enzyme Activities And Deconstruction Of Ammonia-Pretreated Switchgrass By Bacterial-Fungal Communities, Abhiney Jain, H. Sandra Pelle, J. Michael Henson

Biology Faculty Publications

The mixed microbial communities that occur naturally on lignocellulosic feedstocks can provide feedstock-specific enzyme mixtures to saccharify lignocelluloses. Bacterial-fungal communities were enriched from switchgrass bales to deconstruct ammonia-pretreated switchgrass (DSG). Correlation analysis was carried out to elucidate the relationship between microbial decomposition of DSG by these communities, enzymatic activities produced and enzymatic saccharification of DSG using these enzyme mixtures. Results of the analysis showed that β glucosidase activities and xylosidase activities limited the extent of microbial deconstruction and enzymatic saccharification of DSG. The results also underlined the importance of ligninase activity for the enzymatic saccharification of pretreated lignocellulosic feedstock. The …

Exploring Complex Cellular Phenotypes And Model-Guided Strain Design With A Novel Genome-Scale Metabolic Model Of Clostridium Thermocellum Dsm 1313 Implementing An Adjustable Cellulosome, R. Adam Thompson, Sanjeev Dahal, Sergio Garcia, Intawat Nookaew, Cong T. Trinh

Faculty Publications and Other Works -- Chemical and Biomolecular Engineering

Background: Clostridium thermocellum is a gram-positive thermophile that can directly convert lignocellulosic material into biofuels. The metabolism of C. thermocellum contains many branches and redundancies which limit biofuel production, and typical genetic techniques are time-consuming. Further, the genome sequence of a genetically tractable strain C. thermocellum DSM 1313 has been recently sequenced and annotated. Therefore, developing a comprehensive, predictive, genome-scale metabolic model of DSM 1313 is desired for elucidating its complex phenotypes and facilitating model-guided metabolic engineering.

Results: We constructed a genome-scale metabolic model iAT601 for DSM 1313 using the KEGG database as a scaffold and an extensive literature review …

Using Elastin-Like Polypeptides For Better Retention Of Biofuels, Yu Hong Wang, Ethan T. Hilman, Kevin V. Solomon

The Summer Undergraduate Research Fellowship (SURF) Symposium

Elastin-like polypeptides (ELPs) are synthetic molecules that exhibit an interesting property of inverse temperature phase transition; they exist as soluble monomers at low temperatures and form insoluble aggregates at higher temperatures. The transition temperature depends on the pH, salt concentration, and the amino acid sequence of the ELP. This unique and reversible behavior, along with their high biocompatibility has made them a strategic tool for various biomedical applications. However, their hydrophobic properties also make them a prime candidate for biofuel production. As high levels of many commercially important organic solvents are toxic to the cells that make them, ELPs can …

Improving Metabolic Engineering And Characterization Of Clostridium Thermocellum For Improved Cellulosic Ethanol Production, Beth Alexandra Papanek

Doctoral Dissertations

Biofules are an important option for humanity to move away from its dependence on fossil fuels. Transitioning from food crops to lignocellulosic alternatives for the production of biofuels is equally important. Most commonly, biofuels are produced using a crop such as corn or soybeans to feed sugars to the yeast, Saccharomyces cerevisiae for the fermentation of ethanol. Lignocellulosic biofuel production would eliminate the need for food crops and transition to biomass such as switchgrass, poplar, or corn stover. Currently, lignocellulosic biofuel production is limited primarily because of the cost of converting the biomass to fermentable sugars than can then be …

Modification Of Carbohydrate Active Enzymes In Switchgrass (Panicum Virgatum L.) To Improve Saccharification And Biomass Yields For Biofuels, Jonathan Duran Willis

Doctoral Dissertations

The natural recalcitrance of plant cell walls is a major commercial hurdle for plant biomass to be converted into a viable energy source as alternative to fossil fuels. To circumvent this hurdle manipulation of carbohydrate enzymes active in the cellulose and hemicellulose portions of the plant cell wall can be utilized to improve feedstocks. Production of cellulolytic enzymes by plants have been evaluated for reducing the cost associated with lignocellulosic biofuels. Plants have successfully served as bioreactors producing bacterial and fungal glycosyl hydrolases, which have altered plant growth to improve saccharification. A bioprospecting opportunity lies with the utilization of insect …

Monitoring And Mitigation Of Elevated Co2 Impacts Using Microalgae, Terry-Rene Wiesner Brown

USF Tampa Graduate Theses and Dissertations

Climate change is arguably the greatest environmental and economic challenge of our time. There are considerable documented and projected impacts to both human and natural systems as a result of climate change. These impacts include changes in temperature, sea level, precipitation patterns, and biogeography of ecologically and economically relevant species, including pathogens. One of the main drivers of climate change is elevated levels of atmospheric carbon dioxide (CO₂), a greenhouse gas. Since pre-industrial times, atmospheric CO₂ levels have increased from approximately 280 ppm to over 400 ppm, as a result of fossil fuel combustion, cement production and …

Enhancing Algal Biomass And Lipid Production Through Bacterial And Fungal Co-Culture, Erwin David Berthold

FIU Electronic Theses and Dissertations

This thesis investigates the effects of co-culturing microorganisms including 37 yeast, 38 bacteria, nine diazotrophic cyanobacteria, and three fungi on biomass and lipid production in fresh- and saltwater algae. Algal lipid content was measured using Nile Red method and gravimetric techniques. Among the algal strains tested, freshwater Coelastrum sp. 46-4, and saltwater Cricosphaera sp. 146-2-9, showed enhanced biomass yield and lipid content in response to co-culture with bacteria, cyanobacteria, and fungi. While co-culture with yeast caused inhibition of algal productivity, no difference in algal productivity was observed between nitrogen-free diazotrophic cyanobacterial co-culture and nitrogen-replete monoalgal culture. Results indicated that extracellular …

Enhancing Digestibility And Ethanol Yield Of Populus Wood Via Expression Of An Engineered Monolignol 4-O-Methyltransferase, Yuanheng Cai, Kewei Zhang, Hoon Kim, Guichuan Hou, Xuebin Zhang, Huijun Yang, Huan Feng, Lisa Miller, John Ralph, Chang-Jun Liu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Producing cellulosic biofuels and bio-based chemicals from woody biomass is impeded by the presence of lignin polymer in the plant cell wall. Manipulating the monolignol biosynthetic pathway offers a promising approach to improved processability, but often impairs plant growth and development. Here, we show that expressing an engineered 4-O-methyltransferase that chemically modifies the phenolic moiety of lignin monomeric precursors, thus preventing their incorporation into the lignin polymer, substantially alters hybrid aspens’ lignin content and structure. Woody biomass derived from the transgenic aspens shows a 62% increase in the release of simple sugars and up to a 49% increase in the …

Six K-State Professors Receive More Than $3.5 Million In National Science Foundation Career Awards, News And Communications Services

Seek

When the news was announced Kansas State University had not one, or two, but six faculty members whose research was recognized by the National Science Foundation, it was not only a cause for celebration, but a historic first for the university.

Ecological Determinants Of Avian Productivity And Aviation Risk In Semi-Natural Grasslands, Tara Jenise Conkling

Theses and Dissertations

Growing concerns about climate change, foreign oil dependency, and environmental quality have fostered interest in perennial native grasses (e.g. switchgrass [Panicum virgatum]) for bioenergy production while also maintaining biodiversity and ecosystem function. However, biofuel cultivation in marginal landscapes such as airport grasslands may have detrimental effects on aviation safety as well as demography and conservation efforts for grassland birds including Dickcissels (Spiza americana). In 2011–2013 I studied the response of avian populations to vegetation composition and harvest frequency of switchgrass monocultures and native warm-season grass (NWSG) mixtures at B. Bryan farms in Clay Co. MS, USA. Four treatments incorporating switchgrass …

Minimizing Ethanol Concentration In Organosolv Pretreatment For The Saccharification Of Loblolly Pine, Nelson B. Heringer

Biological and Agricultural Engineering Undergraduate Honors Theses

Organic solvent pretreatment, commonly known as organosolv, is a method used to prepare biomass for enzymatic hydrolysis for the production of biofuels. This method common uses ethanol as the organic solvent. However, this creates an economic issue with the product stream, as ethanol becomes a product and input. This project sought to explore how decreasing the use of ethanol in organosolv pretreatment affected the recoverability of sugars after enzymatic hydrolysis. Loblolly pine (Pinus taeda L.) was pretreated at 170 °C for 60 minutes in 1% dilute sulfuric acid and an ethanol concentration varying from 65% to 35%. Compositional …

Algal Wastewater Treatment And Biofuel Production: An Assessment Of Measurement Methods, And Impact Of Nutrient Availability And Species Composition, John F. Chamberlin

Graduate Theses and Dissertations

In order to move towards a more sustainable future, human civilization will need to decrease its impacts on air and water quality and minimize consumption of fossil fuels. Using algae for wastewater treatment and biofuel production offers one approach to progress towards these goals simultaneously. Algae are capable of removing nutrients from wastewater and carbon dioxide from the air, and the biomass formed in that process can be used to generate a wide-range of products including fertilizer or fuels that could power combustion engines, power plants, or zero-emission fuel cell vehicles. Using wastewater for biofuel production has the potential to …

Lipid Content And Biomass Analysis In Autotrophic And Heterotrophic Algal Species, Addie M. Lauder, Daniel P. Jones, Thomas E. Walker, Todd Allen

Montview Journal of Research & Scholarship

Biofuels are a form of renewable energy derived from living matter, typically plants. The push for biofuels began in order to decrease the amount of carbon dioxide (CO2) released into the atmosphere, as biofuels are essentially carbon neutral. The idea is the same amount of CO2 the plants took in to perform photosynthesis will then be released in the burning of the biofuels. Algae is an excellent source of biofuels because it grows quickly and is versatile in terms of the type of fuel it can produce. The two most common mechanisms for algae growth are heterotrophic or photoautotrophic. Heterotrophically …

Parametric Analysis Of A Solid Oxide Fuel Cell Auxiliary Power Unit Operating On Syngas Produced By Autothermal Reforming Of Hydrocarbon Fuels, Jun Dong, Xinhai Xu, Ben Xu, Shuyang Zhang

Mechanical Engineering Faculty Publications and Presentations

A 1 kWe integrated auxiliary power unit (APU) system consisting of an autothermal reformer and a solid oxide fuel cell (SOFC) unit, as well as balance-of-plant components, was designed and analyzed. A relatively easy-to-approach SOFC model was developed in order to conveniently calculate V-I and P-I curves and the system's net efficiency at different operating conditions. The effects of steam to carbon and oxygen to carbon ratios in the reactants, channel dimensions of the SOFC unit, and hydrocarbon fuel types on the integrated APU system's performance were discussed. Five hydrocarbon fuels including diesel, Jet-A, gasoline, ethanol, and methanol were studied …

Biological Lignocellulose Solubilization: Comparative Evaluation Of Biocatalysts And Enhancement Via Cotreatment, Julie M. D. Paye, Anna Guseva, Sarah K. Hammer, Erica Gjersing

Dartmouth Scholarship

Feedstock recalcitrance is the most important barrier impeding cost-effective production of cellulosic biofuels. Pioneer commercial cellulosic ethanol facilities employ thermochemical pretreatment and addition of fungal cellulase, reflecting the main research emphasis in the field. However, it has been suggested that it may be possible to process cellulosic biomass without thermochemical pretreatment using thermophilic, cellulolytic bacteria. To further explore this idea, we examine the ability of various biocatalysts to solubilize autoclaved but otherwise unpretreated cellulosic biomass under controlled but not industrial conditions.

The Effect Of The U.S. Biofuels Mandate On Poverty In India, Ujjayant N. Chakravorty, Marie-Helene Hubert, Beyza Ural Marchand

Ujjayant Chakravorty

More than 40% of US grain is now used for energy and this share is expected to rise under the current Renewable Fuels Mandate (RFS). There are no studies of the global distributional consequences of this purely domestic policy. Using micro-level survey data, we trace the effect of the RFS on world food prices and their impact on household level consumption and wage impacts in India. We first develop a partial equilibrium model to estimate the effect of the RFS on the price of selected food commodities - rice, wheat, corn, sugar and meat and dairy, which together provide almost …

Minimizing Environmental Impacts For Hub And Spoke Distribution Network Problems Through The Use Of Multi-Objective Evolutionary Algorithms, Ileana Delgado

Open Access Theses & Dissertations

While transportation is crucial to our economy and our personal lives, as a sector it is also a significant source of greenhouse gas (GHG) emissions. The AASHTO report states, "America's transportation system has served us well, but now faces the challenges of congestion, energy supply, environmental impacts, climate change, and threatens the economic, social, and environmental future of the nation". With respect to the environment, transportation is the most visible aspect of supply chains. Transportation emissions can be reduced by implementing approaches that contribute to GHG emissions reduction, for example, the use of low-carbon fuels, new and improved vehicle technologies, …

Resolving The Policy Paradox: The Case Of Biofuel Production In Ireland, Alan Gilmer, Mark J. Mcgarrity, Vivienne Byers

Articles

Purpose – The purpose of this paper is to determine the status of policy design and policy implementation in the biofuel sector in Ireland. The focus of the work addresses the overarching operational context of the biofuel sector in Ireland and the role of different actors in shaping and resolving inconsistencies in policy outlook and practice. Design/methodology/approach – This study used a qualitative research approach involving a series of semi-structured interviews with members of the relevant sub-groups concerned. This study sought to address two questions – whether current or proposed policy is likely to affect consumption of indigenous biofuel feedstocks …

Fundamental Studies Of Collision-Activated Dissociation (Cad) Of Deprotonated Model Compounds Relevant To Lignin Degradation Products, Christopher Louis Marcum

Open Access Dissertations

ABSTRACT

Biomass Catalytic Upconversion With A Metallic Catalyst Bed Under Radio Frequency Induction Heating, Mohammad Abu-Laban

LSU Master's Theses

This study investigated the thermal performances of platinum particles when coupled on a steel support, under the application of a radio frequency (RF) field. Platinum nanoparticles were reduced on the surfaces of type-316 stainless steel balls, based on published methods of Pt reduction from chloroplatinic acid. Alternatively, 1wt. % Pt/Al2O3 commercial catalyst pellets were mixed with stainless steel balls and investigated for hydro-deoxygenation of pyrolysis oil from pine sawdust biomass. The catalysts were placed inside an electric insulator tube suspended within a looping copper coil connected to the induction heater, and heated at different power levels. An infrared camera was …

Induction Of Cellulase In High Solids Cultivation Of Trichoderma Reesei For Enhanced Enzymatic Hydrolysis Of Lignocellulose, Danielle Empson

Theses and Dissertations--Biosystems and Agricultural Engineering

This project aimed investigated cellulase in-situ production for large-scale on-farm production of lignocellulosic biofuel. Cellulase activity and glucose released by T. reesei with corn stover and wheat bran as co-substrates for solid state cultivation (SSC) were examined. Co-cultivation has previously increased T. reesei cellulase, but corn stover and wheat bran have not been co-cultivated (Dhillon, Oberoi et al. 2011). This work compared cellulase activity and glucose concentration of corn stover co-cultivated with 0-40% wheat bran in high solids. Samples with at least 20% wheat bran exhibited increased cellulase activity. However, the average glucose concentration without wheat bran was 3.29 g/L …

Experimental And Theoretical Investigation Of Sustainable Fast Pyrolysis Biofuels From Woody Biomass, Bethany Jean Klemetsrud

Dissertations, Master's Theses and Master's Reports

Biofuels are an important advancement in alternative energy that can provide substantial environmental benefits compared to their conventional fossil fuel counterparts Said benefits are usually measured using life cycle assessments. However, it is not well understood yet how different methodological choices such as system boundaries, biomass feedstocks, conversion pathways, geographical data, etc. affect the conclusions drawn from biofuels LCA. This research shows large variability in life cycle assessment results and limits comparison across different biofuel pathways due to methodological choices set forth by policy and certification schemes. Advanced biofuels have not reached large scale production due to a limited understanding …

The Environmental Justice Implications Of Biofuels, Carmen G. Gonzalez

Carmen G. Gonzalez