The Experts below are selected from a list of 26169 Experts worldwide ranked by ideXlab platform
Tony Vancov - One of the best experts on this subject based on the ideXlab platform.
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optimisation of dilute alkaline pretreatment for enzymatic Saccharification of wheat straw
Biomass & Bioenergy, 2011Co-Authors: Shane Mcintosh, Tony VancovAbstract:Physico-chemical pretreatment of lignocellulosic biomass is critical in removing substrate-specific barriers to cellulolytic enzyme attack. Alkaline pretreatment successfully delignifies biomass by disrupting the ester bonds cross-linking lignin and xylan, resulting in cellulose and hemicellulose enriched fractions. Here we report the use of dilute alkaline (NaOH) pretreatment followed by enzyme Saccharifications of wheat straw to produce fermentable sugars. Specifically, we have assessed the impacts of varying pretreatment parameters (temperature, time and alkalinity) on enzymatic digestion of residual solid materials. Following pretreatment, recoverable solids and lignin contents were found to be inversely proportional to the severity of the pretreatment process. Elevating temperature and alkaline strengths maximised hemicellulose and lignin solubilisation and enhanced enzymatic Saccharifications. Pretreating wheat straw with 2% NaOH for 30 min at 121 °C improved enzyme Saccharification 6.3-fold when compared to control samples. Similarly, a 4.9-fold increase in total sugar yields from samples treated with 2% NaOH at 60 °C for 90min, confirmed the importance of alkali inclusion. A combination of three commercial enzyme preparations (cellulase, β-glucosidase and xylanase) was found to maximise monomeric sugar release, particularly for substrates with higher xylan contents. In essence, the combined enzyme activities increased total sugar release 1.65-fold and effectively reduced cellulase enzyme loadings 3-fold. Prehydrolysate liquors contained 4-fold more total phenolics compared to enzyme Saccharification mixtures. Harsher pretreatment conditions provide saccharified hydrolysates with reduced phenolic content and greater fermentation potential.
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alkali pretreatment of cereal crop residues for second generation biofuels
Energy & Fuels, 2011Co-Authors: Tony Vancov, Shane McintoshAbstract:Mild alkali cooking of lignocellulosic biomass is an effective pretreatment method, which improves enzymatic hydrolysis. Here, we report the use of dilute alkali (NaOH) pretreatment followed by enzyme Saccharification of cereal residues for their potential to serve as feedstock in the production of next-generation biofuels in Australia. After pretreatment, both solids and lignin content were found to be inversely proportional to treatment severity. We also found that higher temperatures and alkali strength were quintessential for maximizing sugar recoveries from enzyme Saccharifications. Generally, pretreatment conditions at elevated temperatures led to highly digestible material enriched in both cellulose and hemicellulose components. Increasing cellulase loadings and tailoring enzyme activities with additional β-glucosidases and xylanases delivered greater rates of monosaccharide sugar release and yields throughout enzyme hydrolysis. Considering their abundance, high sugar potential, and apparent ease o...
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Optimisation of dilute alkaline pretreatment for enzymatic Saccharification of wheat straw
Biomass and Bioenergy, 2011Co-Authors: Shane Mcintosh, Tony VancovAbstract:Physico-chemical pretreatment of lignocellulosic biomass is critical in removing substrate-specific barriers to cellulolytic enzyme attack. Alkaline pretreatment successfully delignifies biomass by disrupting the ester bonds cross-linking lignin and xylan, resulting in cellulose and hemicellulose enriched fractions. Here we report the use of dilute alkaline (NaOH) pretreatment followed by enzyme Saccharifications of wheat straw to produce fermentable sugars. Specifically, we have assessed the impacts of varying pretreatment parameters (temperature, time and alkalinity) on enzymatic digestion of residual solid materials. Following pretreatment, recoverable solids and lignin contents were found to be inversely proportional to the severity of the pretreatment process. Elevating temperature and alkaline strengths maximised hemicellulose and lignin solubilisation and enhanced enzymatic Saccharifications. Pretreating wheat straw with 2% NaOH for 30 min at 121 ??C improved enzyme Saccharification 6.3-fold when compared to control samples. Similarly, a 4.9-fold increase in total sugar yields from samples treated with 2% NaOH at 60 ??C for 90min, confirmed the importance of alkali inclusion. A combination of three commercial enzyme preparations (cellulase, ??-glucosidase and xylanase) was found to maximise monomeric sugar release, particularly for substrates with higher xylan contents. In essence, the combined enzyme activities increased total sugar release 1.65-fold and effectively reduced cellulase enzyme loadings 3-fold. Prehydrolysate liquors contained 4-fold more total phenolics compared to enzyme Saccharification mixtures. Harsher pretreatment conditions provide saccharified hydrolysates with reduced phenolic content and greater fermentation potential. ?? 2011 Elsevier Ltd.
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enhanced enzyme Saccharification of sorghum bicolor straw using dilute alkali pretreatment
Bioresource Technology, 2010Co-Authors: Shane Mcintosh, Tony VancovAbstract:Abstract The impacts of varying pretreatment parameters (temperature, time, and alkalinity) on enzymatic hydrolysis of sorghum straw were investigated. Following pretreatment, both solids and lignin content was found to be inversely proportional to the severity of the treatments. Higher temperatures and alkali strength were quintessential for maximising sugar recoveries from enzyme Saccharifications. Total sugar release peaked when sorghum straw was pretreated in 2% NaOH at 121 °C for 60 min; representing a 5.6-fold higher yield compared to samples pretreated at 60 °C in the absence of alkali. Similarly, 4.3-fold increases in total sugars from samples treated with 2% NaOH at 60 °C for 90 min, confirmed the importance of alkali inclusion. Addition of β-glucosidase and xylanase to Saccharification mixtures enhanced reaction rates and final sugar yields, whilst reducing cellulase dosage 4-fold. Saccharification efficiency of pretreated solids approached 90% and 95% (w/w) with as little as 2.5 and 5.0 FPU cellulase/g, respectively.
Shane Mcintosh - One of the best experts on this subject based on the ideXlab platform.
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optimisation of dilute alkaline pretreatment for enzymatic Saccharification of wheat straw
Biomass & Bioenergy, 2011Co-Authors: Shane Mcintosh, Tony VancovAbstract:Physico-chemical pretreatment of lignocellulosic biomass is critical in removing substrate-specific barriers to cellulolytic enzyme attack. Alkaline pretreatment successfully delignifies biomass by disrupting the ester bonds cross-linking lignin and xylan, resulting in cellulose and hemicellulose enriched fractions. Here we report the use of dilute alkaline (NaOH) pretreatment followed by enzyme Saccharifications of wheat straw to produce fermentable sugars. Specifically, we have assessed the impacts of varying pretreatment parameters (temperature, time and alkalinity) on enzymatic digestion of residual solid materials. Following pretreatment, recoverable solids and lignin contents were found to be inversely proportional to the severity of the pretreatment process. Elevating temperature and alkaline strengths maximised hemicellulose and lignin solubilisation and enhanced enzymatic Saccharifications. Pretreating wheat straw with 2% NaOH for 30 min at 121 °C improved enzyme Saccharification 6.3-fold when compared to control samples. Similarly, a 4.9-fold increase in total sugar yields from samples treated with 2% NaOH at 60 °C for 90min, confirmed the importance of alkali inclusion. A combination of three commercial enzyme preparations (cellulase, β-glucosidase and xylanase) was found to maximise monomeric sugar release, particularly for substrates with higher xylan contents. In essence, the combined enzyme activities increased total sugar release 1.65-fold and effectively reduced cellulase enzyme loadings 3-fold. Prehydrolysate liquors contained 4-fold more total phenolics compared to enzyme Saccharification mixtures. Harsher pretreatment conditions provide saccharified hydrolysates with reduced phenolic content and greater fermentation potential.
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alkali pretreatment of cereal crop residues for second generation biofuels
Energy & Fuels, 2011Co-Authors: Tony Vancov, Shane McintoshAbstract:Mild alkali cooking of lignocellulosic biomass is an effective pretreatment method, which improves enzymatic hydrolysis. Here, we report the use of dilute alkali (NaOH) pretreatment followed by enzyme Saccharification of cereal residues for their potential to serve as feedstock in the production of next-generation biofuels in Australia. After pretreatment, both solids and lignin content were found to be inversely proportional to treatment severity. We also found that higher temperatures and alkali strength were quintessential for maximizing sugar recoveries from enzyme Saccharifications. Generally, pretreatment conditions at elevated temperatures led to highly digestible material enriched in both cellulose and hemicellulose components. Increasing cellulase loadings and tailoring enzyme activities with additional β-glucosidases and xylanases delivered greater rates of monosaccharide sugar release and yields throughout enzyme hydrolysis. Considering their abundance, high sugar potential, and apparent ease o...
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Optimisation of dilute alkaline pretreatment for enzymatic Saccharification of wheat straw
Biomass and Bioenergy, 2011Co-Authors: Shane Mcintosh, Tony VancovAbstract:Physico-chemical pretreatment of lignocellulosic biomass is critical in removing substrate-specific barriers to cellulolytic enzyme attack. Alkaline pretreatment successfully delignifies biomass by disrupting the ester bonds cross-linking lignin and xylan, resulting in cellulose and hemicellulose enriched fractions. Here we report the use of dilute alkaline (NaOH) pretreatment followed by enzyme Saccharifications of wheat straw to produce fermentable sugars. Specifically, we have assessed the impacts of varying pretreatment parameters (temperature, time and alkalinity) on enzymatic digestion of residual solid materials. Following pretreatment, recoverable solids and lignin contents were found to be inversely proportional to the severity of the pretreatment process. Elevating temperature and alkaline strengths maximised hemicellulose and lignin solubilisation and enhanced enzymatic Saccharifications. Pretreating wheat straw with 2% NaOH for 30 min at 121 ??C improved enzyme Saccharification 6.3-fold when compared to control samples. Similarly, a 4.9-fold increase in total sugar yields from samples treated with 2% NaOH at 60 ??C for 90min, confirmed the importance of alkali inclusion. A combination of three commercial enzyme preparations (cellulase, ??-glucosidase and xylanase) was found to maximise monomeric sugar release, particularly for substrates with higher xylan contents. In essence, the combined enzyme activities increased total sugar release 1.65-fold and effectively reduced cellulase enzyme loadings 3-fold. Prehydrolysate liquors contained 4-fold more total phenolics compared to enzyme Saccharification mixtures. Harsher pretreatment conditions provide saccharified hydrolysates with reduced phenolic content and greater fermentation potential. ?? 2011 Elsevier Ltd.
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enhanced enzyme Saccharification of sorghum bicolor straw using dilute alkali pretreatment
Bioresource Technology, 2010Co-Authors: Shane Mcintosh, Tony VancovAbstract:Abstract The impacts of varying pretreatment parameters (temperature, time, and alkalinity) on enzymatic hydrolysis of sorghum straw were investigated. Following pretreatment, both solids and lignin content was found to be inversely proportional to the severity of the treatments. Higher temperatures and alkali strength were quintessential for maximising sugar recoveries from enzyme Saccharifications. Total sugar release peaked when sorghum straw was pretreated in 2% NaOH at 121 °C for 60 min; representing a 5.6-fold higher yield compared to samples pretreated at 60 °C in the absence of alkali. Similarly, 4.3-fold increases in total sugars from samples treated with 2% NaOH at 60 °C for 90 min, confirmed the importance of alkali inclusion. Addition of β-glucosidase and xylanase to Saccharification mixtures enhanced reaction rates and final sugar yields, whilst reducing cellulase dosage 4-fold. Saccharification efficiency of pretreated solids approached 90% and 95% (w/w) with as little as 2.5 and 5.0 FPU cellulase/g, respectively.
Lakshmi Tewari - One of the best experts on this subject based on the ideXlab platform.
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Optimization of Saccharification of sweet sorghum bagasse using response surface methodology
Industrial Crops and Products, 2013Co-Authors: Jitendra K. Saini, Arti Arya, Baburao K. Kumbhar, Rahul K. Anurag, Lakshmi TewariAbstract:The lignocellulose rich sweet sorghum bagasse (SSB) is a good feedstock for bioethanol production after conversion of its insoluble carbohydrates, mainly cellulose, to fermentable sugars. Main focus of the present investigation was therefore, to determine the optimum conditions for enzymatic Saccharification of SSB using indigenously produced cellulases from a novel fungal consortium of Aspergillus flavus F-80 and Aspergillus niger MTCC-2425. Response surface methodology was adopted by using a three factor-three level Box-Behnken design by selecting substrate concentration (%, w/v), Saccharification time (h) and enzyme loading (FPUg-1substrate) as the main process parameters. Data obtained from RSM were subjected to the analysis of variance (ANOVA) and analyzed using a second order polynomial equation. The developed model was found to be robust and was used to optimize the % Saccharification yield during enzymatic hydrolysis. Under optimized conditions (substrate concentration 6%, w/v, time 48h and enzyme loading of 22FPUg-1substrate), maximum Saccharification yield of 51.21% was achieved. Structural modification of SSB due to enzymatic Saccharification was supported by changes in thermal decomposition behavior and pore formation observed during thermogravimetric and SEM analysis, respectively. ?? 2012 Elsevier B.V.
Lucas F Ribeiro - One of the best experts on this subject based on the ideXlab platform.
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a xylose stimulated xylanase xylose binding protein chimera created by random nonhomologous recombination
Biotechnology for Biofuels, 2016Co-Authors: Lucas F Ribeiro, Jennifer Tullman, Nathan Nicholes, Sergio R B Silva, Davi Serradella Vieira, Marc Ostermeier, Richard J WardAbstract:Background Saccharification of lignocellulosic material by xylanases and other glycoside hydrolases is generally conducted at high concentrations of the final reaction products, which frequently inhibit the enzymes used in the Saccharification process. Using a random nonhomologous recombination strategy, we have fused the GH11 xylanase from Bacillus subtilis (XynA) with the xylose binding protein from Escherichia coli (XBP) to produce an enzyme that is allosterically stimulated by xylose.
Wout Boerjan - One of the best experts on this subject based on the ideXlab platform.
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lignin biosynthesis perturbations affect secondary cell wall composition and Saccharification yield in arabidopsis thaliana
Biotechnology for Biofuels, 2013Co-Authors: Rebecca Van Acker, Ruben Vanholme, Veronique Storme, Jennifer C Mortimer, Paul Dupree, Wout BoerjanAbstract:Background: Second-generation biofuels are generally produced from the polysaccharides in the lignocellulosic plant biomass, mainly cellulose. However, because cellulose is embedded in a matrix of other polysaccharides and lignin, its hydrolysis into the fermentable glucose is hampered. The senesced inflorescence stems of a set of 20 Arabidopsis thaliana mutants in 10 different genes of the lignin biosynthetic pathway were analyzed for cell wall composition and Saccharification yield. Saccharification models were built to elucidate which cell wall parameters played a role in cell wall recalcitrance. Results: Although lignin is a key polymer providing the strength necessary for the plant’s ability to grow upward, a reduction in lignin content down to 64% of the wild-type level in Arabidopsis was tolerated without any obvious growth penalty. In contrast to common perception, we found that a reduction in lignin was not compensated for by an increase in cellulose, but rather by an increase in matrix polysaccharides. In most lignin mutants, the Saccharification yield was improved by up to 88% cellulose conversion for the cinnamoyl-coenzyme A reductase1 mutants under pretreatment conditions, whereas the wild-type cellulose conversion only reached 18%. The Saccharification models and Pearson correlation matrix revealed that the lignin content was the main factor determining the Saccharification yield. However, also lignin composition, matrix polysaccharide content and composition, and, especially, the xylose, galactose, and arabinose contents influenced the Saccharification yield. Strikingly, cellulose content did not significantly affect Saccharification yield. Conclusions: Although the lignin content had the main effect on Saccharification, also other cell wall factors could be engineered to potentially increase the cell wall processability, such as the galactose content. Our results contribute to a better understanding of the effect of lignin perturbations on plant cell wall composition and its influence on Saccharification yield, and provide new potential targets for genetic improvement.
