The Experts below are selected from a list of 93 Experts worldwide ranked by ideXlab platform
David R. Shonnard - One of the best experts on this subject based on the ideXlab platform.
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Feedstock mixture effects on sugar monomer recovery following dilute acid pretreatment and enzymatic hydrolysis.
Bioresource technology, 2012Co-Authors: Michael J. Brodeur-campbell, Jordan Klinger, David R. ShonnardAbstract:This study seeks to investigate the effects of biomass mixtures on overall sugar recovery from the combined processes of dilute acid pretreatment and enzymatic hydrolysis. Aspen, a hardwood species well suited to biochemical processing, was chosen as the model species for this study. Balsam, a high-lignin softwood species, and switchgrass, an Herbaceous Energy Crop with high ash content, were chosen as adjuncts. A matrix of three different dilute acid pretreatment severities and three different enzyme loading levels was used to characterize interactions between pretreatment and enzymatic hydrolysis. No synergism or antagonism was observed for any of the feedstock mixtures. Maximum glucose yield was 70% of theoretical for switchgrass and maximum xylose yield was 99.7% of theoretical for aspen. Supplemental β-glucosidase increased glucose yield from enzymatic hydrolysis by an average of 15%. Total sugar recoveries for mixtures could be predicted to within 4% by linear interpolation of the pure species results.
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effects of dilute acid pretreatment conditions on enzymatic hydrolysis monomer and oligomer sugar yields for aspen balsam and switchgrass
Bioresource Technology, 2010Co-Authors: Jill R Jensen, Juan E Morinelly, Kelsey R Gossen, Michael J Brodeurcampbell, David R. ShonnardAbstract:Abstract The effects of dilute acid hydrolysis conditions were investigated on total sugar (glucose and xylose) yields after enzymatic hydrolysis with additional analyses on glucose and xylose monomer and oligomer yields from the individual hydrolysis steps for aspen (a hardwood), balsam (a softwood), and switchgrass (a Herbaceous Energy Crop). The results of this study, in the form of measured versus theoretical yields and a severity analysis, show that for aspen and balsam, high dilute acid hydrolysis xylose yields were obtainable at all acid concentrations (0.25–0.75 wt.%) and temperatures (150–175 °C) studied as long as reaction time was optimized. Switchgrass shows a relatively stronger dependence on dilute acid hydrolysis acid concentration due to its higher neutralizing mineral content. Maximum total sugar (xylose and glucose; monomer plus oligomer) yields post-enzymatic hydrolysis for aspen, balsam, and switchgrass, were 88.3%, 21.2%, and 97.6%, respectively. In general, highest yields of total sugars (xylose and glucose; monomer plus oligomer) were achieved at combined severity parameter values (log CS) between 2.20 and 2.40 for the biomass species studied.
Michael D. Casler - One of the best experts on this subject based on the ideXlab platform.
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Candidate Variants for Additive and Interactive Effects on BioEnergy Traits in Switchgrass (Panicum virgatum L.) Identified by Genome-Wide Association Analyses.
The plant genome, 2018Co-Authors: Guillaume P. Ramstein, Joseph Evans, Aruna Nandety, Malay C. Saha, E. Charles Brummer, Shawn M. Kaeppler, C. Robin Buell, Michael D. CaslerAbstract:Switchgrass ( L.) is a promising Herbaceous Energy Crop, but further gains in biomass yield and quality must be achieved to enable a viable bioEnergy industry. Developing DNA markers can contribute to such progress, but depiction of genetic bases should be reliable, involving simple additive marker effects and also interactions with genetic backgrounds (e.g., ecotypes) or synergies with other markers. We analyzed plant height, C content, N content, and mineral concentration in a diverse panel consisting of 512 genotypes of upland and lowland ecotypes. We performed association analyses based on exome capture sequencing and tested 439,170 markers for marginal effects, 83,290 markers for marker × ecotype interactions, and up to 311,445 marker pairs for pairwise interactions. Analyses of pairwise interactions focused on subsets of marker pairs preselected on the basis of marginal marker effects, gene ontology annotation, and pairwise marker associations. Our tests identified 12 significant effects. Homology and gene expression information corroborated seven effects and indicated plausible causal pathways: flowering time and lignin synthesis for plant height; plant growth and senescence for C content and mineral concentration. Four pairwise interactions were detected, including three interactions preselected on the basis of pairwise marker correlations. Furthermore, a marker × ecotype interaction and a pairwise interaction were confirmed in an independent switchgrass panel. Our analyses identified reliable candidate variants for important bioEnergy traits. Moreover, they exemplified the importance of interactive effects for depicting genetic bases and illustrated the usefulness of preselecting marker pairs for identifying pairwise marker interactions in association studies.
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The Evolution of Switchgrass as an Energy Crop
Green Energy and Technology, 2012Co-Authors: David J. Parrish, Michael D. Casler, Andrea MontiAbstract:This chapter discusses the prehistoric origins of switchgrass, its mid-twentieth century adoption as a Crop, and late-twentieth century efforts to develop it into an Energy Crop. The species probably first appeared about 2 million years ago (MYA) and has continued to evolve since, producing two distinct ecotypes and widely varying ploidy levels. We build the case that all existing switchgrass lineages must be descended from plants that survived the most recent glaciation of North America and then, in just 11,000 years, re-colonized the eastern two-thirds of the continent. Moving to historic times, we discuss how switchgrass was first considered as a Crop to be grown in monoculture only in the 1940s. Based on scientific reports indexed in a well-known database, interest in switchgrass grew very slowly from the 1940s until it began being considered by the US department of Energy (DOE) as a potential Energy Crop in the 1980s. The history of how switchgrass became DOE’s ‘model’ Herbaceous Energy Crop species is recounted here. Also chronicled are the early research efforts on switchgrass-for-Energy in the US, Canada, and Europe and the explosive growth in the last decade of publications discussing switchgrass as an Energy Crop. If switchgrass—still very much a ‘wild’ species, especially compared to several domesticated grasses—truly attains global status as a species of choice for bioEnergy technologies, it will have been a very remarkable evolution.
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Switchgrass as a biofuels feedstock in the USA
Canadian Journal of Plant Science, 2006Co-Authors: Matt A Sanderson, Michael D. Casler, Paul R. Adler, Akwasi A. Boateng, Gautam SarathAbstract:Switchgrass (Panicum virgatum L.) has been identified as a model Herbaceous Energy Crop for the USA. In this review, we selectively highlight current USDA-ARS research on switchgrass for biomass Energy. Intensive research on switchgrass as a biomass feedstock in the 1990s greatly improved our understanding of the adaptation of switchgrass cultivars, production practices, and environmental benefits. Several constraints still remain in terms of economic production of switchgrass for biomass feedstock including reliable establishment practices to ensure productive stands in the seeding year, efficient use of fertilizers, and more efficient methods to convert lignocellulose to biofuels. Overcoming the biological constraints will require genetic enhancement, molecular biology, and plant breeding efforts to improve switchgrass cultivars. New genomic resources will aid in developing molecular markers, and should allow for marker-assisted selection of improved germplasm. Research is also needed on profitable mana...
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Switchgrass as a biofuels feedstock in the USA
Canadian Journal of Plant Science, 2006Co-Authors: M. A. Sanderson, Paul R. Adler, Michael D. Casler, Akwasi A. Boateng, Gautam SarathAbstract:Switchgrass (Panicum virgatum L.) has been identified as a model Herbaceous Energy Crop for the USA. In this review, we selectively highlight current USDA-ARS research on switchgrass for biomass Energy. Intensive research on switchgrass as a biomass feedstock in the 1990s greatly improved our understanding of the adaptation of switchgrass cultivars, production practices, and environmental benefits. Several constraints still remain in terms of economic production of switchgrass for biomass feedstock including reliable establishment practices to ensure productive stands in the seeding year, efficient use of fertilizers, and more efficient methods to convert lignocellulose to biofuels. Overcoming the biological constraints will require genetic enhancement, molecular biology, and plant breeding efforts to improve switchgrass cultivars. New genomic resources will aid in developing molecular markers, and should allow for marker-assisted selection of improved germplasm. Research is also needed on profitable management practices for switchgrass production appropriate to specific agro-ecoregions and breakthroughs in conversion methodology. Current higher costs of biofuels compared to fossil fuels may be offset by accurately valuing environmental benefits associated with perennial grasses such as reduced runoff and erosion and associated reduced losses of soil nutrients and organic matter, increased incorporation of soil carbon and reduced use of agricultural chemicals. Use of warm-season perennial grasses in bioEnergy Cropping systems may also mitigate increases in atmospheric CO2. A critical need is teams of scientists, extension staff, and producer-cooperators in key agro-ecoregions to develop profitable management practices for the production of biomass feedstocks appropriate to those agro-ecoregions. Key words: BioEnergy, biomass conversion technologies, Panicum virgatum L., stand establishment, switchgrass improvement, USDA-ARS
Michael J. Brodeur-campbell - One of the best experts on this subject based on the ideXlab platform.
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Feedstock mixture effects on sugar monomer recovery following dilute acid pretreatment and enzymatic hydrolysis.
Bioresource technology, 2012Co-Authors: Michael J. Brodeur-campbell, Jordan Klinger, David R. ShonnardAbstract:This study seeks to investigate the effects of biomass mixtures on overall sugar recovery from the combined processes of dilute acid pretreatment and enzymatic hydrolysis. Aspen, a hardwood species well suited to biochemical processing, was chosen as the model species for this study. Balsam, a high-lignin softwood species, and switchgrass, an Herbaceous Energy Crop with high ash content, were chosen as adjuncts. A matrix of three different dilute acid pretreatment severities and three different enzyme loading levels was used to characterize interactions between pretreatment and enzymatic hydrolysis. No synergism or antagonism was observed for any of the feedstock mixtures. Maximum glucose yield was 70% of theoretical for switchgrass and maximum xylose yield was 99.7% of theoretical for aspen. Supplemental β-glucosidase increased glucose yield from enzymatic hydrolysis by an average of 15%. Total sugar recoveries for mixtures could be predicted to within 4% by linear interpolation of the pure species results.
Jill R Jensen - One of the best experts on this subject based on the ideXlab platform.
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effects of dilute acid pretreatment conditions on enzymatic hydrolysis monomer and oligomer sugar yields for aspen balsam and switchgrass
Bioresource Technology, 2010Co-Authors: Jill R Jensen, Juan E Morinelly, Kelsey R Gossen, Michael J Brodeurcampbell, David R. ShonnardAbstract:Abstract The effects of dilute acid hydrolysis conditions were investigated on total sugar (glucose and xylose) yields after enzymatic hydrolysis with additional analyses on glucose and xylose monomer and oligomer yields from the individual hydrolysis steps for aspen (a hardwood), balsam (a softwood), and switchgrass (a Herbaceous Energy Crop). The results of this study, in the form of measured versus theoretical yields and a severity analysis, show that for aspen and balsam, high dilute acid hydrolysis xylose yields were obtainable at all acid concentrations (0.25–0.75 wt.%) and temperatures (150–175 °C) studied as long as reaction time was optimized. Switchgrass shows a relatively stronger dependence on dilute acid hydrolysis acid concentration due to its higher neutralizing mineral content. Maximum total sugar (xylose and glucose; monomer plus oligomer) yields post-enzymatic hydrolysis for aspen, balsam, and switchgrass, were 88.3%, 21.2%, and 97.6%, respectively. In general, highest yields of total sugars (xylose and glucose; monomer plus oligomer) were achieved at combined severity parameter values (log CS) between 2.20 and 2.40 for the biomass species studied.
Jordan Klinger - One of the best experts on this subject based on the ideXlab platform.
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Feedstock mixture effects on sugar monomer recovery following dilute acid pretreatment and enzymatic hydrolysis.
Bioresource technology, 2012Co-Authors: Michael J. Brodeur-campbell, Jordan Klinger, David R. ShonnardAbstract:This study seeks to investigate the effects of biomass mixtures on overall sugar recovery from the combined processes of dilute acid pretreatment and enzymatic hydrolysis. Aspen, a hardwood species well suited to biochemical processing, was chosen as the model species for this study. Balsam, a high-lignin softwood species, and switchgrass, an Herbaceous Energy Crop with high ash content, were chosen as adjuncts. A matrix of three different dilute acid pretreatment severities and three different enzyme loading levels was used to characterize interactions between pretreatment and enzymatic hydrolysis. No synergism or antagonism was observed for any of the feedstock mixtures. Maximum glucose yield was 70% of theoretical for switchgrass and maximum xylose yield was 99.7% of theoretical for aspen. Supplemental β-glucosidase increased glucose yield from enzymatic hydrolysis by an average of 15%. Total sugar recoveries for mixtures could be predicted to within 4% by linear interpolation of the pure species results.