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I.a. Panagiotopoulos - One of the best experts on this subject based on the ideXlab platform.
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effect of low severity dilute acid pretreatment of Barley Straw and decreased enzyme loading hydrolysis on the production of fermentable substrates and the release of inhibitory compounds
Journal of Cleaner Production, 2012Co-Authors: R R Bakker, I.a. Panagiotopoulos, George D Lignos, E G KoukiosAbstract:Abstract The objective of this work was to investigate the feasibility of combining low severity dilute-acid pretreatment of Barley Straw and decreased enzyme loading hydrolysis for the high production of fermentable substrates and the low release of inhibitory compounds. For most of the pretreatments at 160 and 180 °C, the sugar production with 15 FPU (filter paper unit)/g Straw was equally high compared to higher enzyme loadings. For the pretreatments at 170 °C an enzyme loading higher than 15 FPU/g Straw was necessary to achieve a carbohydrate conversion of 50% or higher. The effect of acid loading on sugar production was discernible only in the experiments with 15 FPU/g Straw or higher. The concentration of 5-hydroxymethylfurfural (HMF), levulinic acid and formic acid was kept below 0.7, 0.6 and 0.8 g L−1, respectively, with all experiments. The release of acetic acid and furfural reached toxic levels with experiments at 170 °C and experiments at 180 °C, respectively. Decreasing the enzyme loading did not have a major effect on the release of HMF, furfural and formic acid but resulted in decreased release of acetic acid and levulinic acid at 170 and 180 °C.
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dilute acid pretreatment of Barley Straw for biological hydrogen production using caldicellulosiruptor saccharolyticus
International Journal of Hydrogen Energy, 2012Co-Authors: R R Bakker, I.a. Panagiotopoulos, G J De Vrije, E G KoukiosAbstract:Abstract The main objective of this study was to use the fermentability test to investigate the feasibility of applying various dilute acids in the pretreatment of Barley Straw for biological hydrogen production. At a fixed acid loading of 1% (w/w dry matter) 28–32% of Barley Straw was converted to soluble monomeric sugars, while at a fixed combined severity of −0.8 30–32% of the Straw was converted to soluble monomeric sugars. With fermentability tests at sugar concentrations 10 and 20 g/L the extreme thermophilic bacterium Caldicellulosiruptor saccharolyticus showed good hydrogen production on hydrolysates of Straw pretreated with H3PO4 and H2SO4, and to a lesser extent, HNO3. The fermentability of the hydrolysate of Straw pretreated with HCl was lower compared to the other acids but equally high as that of pure sugars. At sugar concentration 30 g/L the fermentability of all hydrolysates was low.
Justin Powlowski - One of the best experts on this subject based on the ideXlab platform.
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formulation of enzyme blends to maximize the hydrolysis of alkaline peroxide pretreated alfalfa hay and Barley Straw by rumen enzymes and commercial cellulases
BMC Biotechnology, 2014Co-Authors: Ajay Badhan, Yuxi Wang, Donald Patton, Justin PowlowskiAbstract:Efficient conversion of lignocellulosic biomass to fermentable sugars requires the synergistic action of multiple enzymes; consequently enzyme mixtures must be properly formulated for effective hydrolysis. The nature of an optimal enzyme blends depends on the type of pretreatment employed as well the characteristics of the substrate. In this study, statistical experimental design was used to develop mixtures of recombinant glycosyl hydrolases from thermophilic and anaerobic fungi that enhanced the digestion of alkaline peroxide treated alfalfa hay and Barley Straw by mixed rumen enzymes as well as commercial cellulases (Accelerase 1500, A1500; Accelerase XC, AXC). Combinations of feruloyl and acetyl xylan esterases (FAE1a; AXE16A_ASPNG), endoglucanase GH7 (EGL7A_THITE) and polygalacturonase (PGA28A_ASPNG) with rumen enzymes improved Straw digestion. Inclusion of pectinase (PGA28A_ASPNG), endoxylanase (XYN11A_THITE), feruloyl esterase (FAE1a) and β-glucosidase (E-BGLUC) with A1500 or endoglucanase GH7 (EGL7A_THITE) and β-xylosidase (E-BXSRB) with AXC increased glucose release from alfalfa hay. Glucose yield from Straw was improved when FAE1a and endoglucanase GH7 (EGL7A_THITE) were added to A1500, while FAE1a and AXE16A_ASPNG enhanced the activity of AXC on Straw. Xylose release from alfalfa hay was augmented by supplementing A1500 with E-BGLUC, or AXC with EGL7A_THITE and XYN11A_THITE. Adding arabinofuranosidase (ABF54B_ASPNG) and esterases (AXE16A_ASPNG; AXE16B_ASPNG) to A1500, or FAE1a and AXE16A_ASPNG to AXC enhanced xylose release from Barley Straw, a response confirmed in a scaled up assay. The efficacy of commercial enzyme mixtures as well as mixed enzymes from the rumen was improved through formulation with synergetic recombinant enzymes. This approach reliably identified supplemental enzymes that enhanced sugar release from alkaline pretreated alfalfa hay and Barley Straw.
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formulation of enzyme blends to maximize the hydrolysis of alkaline peroxide pretreated alfalfa hay and Barley Straw by rumen enzymes and commercial cellulases
BMC Biotechnology, 2014Co-Authors: Ajay Badhan, Robert J. Gruninger, Yuxi Wang, Donald Patton, Justin Powlowski, Adrian TsangAbstract:Background Efficient conversion of lignocellulosic biomass to fermentable sugars requires the synergistic action of multiple enzymes; consequently enzyme mixtures must be properly formulated for effective hydrolysis. The nature of an optimal enzyme blends depends on the type of pretreatment employed as well the characteristics of the substrate. In this study, statistical experimental design was used to develop mixtures of recombinant glycosyl hydrolases from thermophilic and anaerobic fungi that enhanced the digestion of alkaline peroxide treated alfalfa hay and Barley Straw by mixed rumen enzymes as well as commercial cellulases (Accelerase 1500, A1500; Accelerase XC, AXC).
Ari Pappinen - One of the best experts on this subject based on the ideXlab platform.
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enhanced sugar production from pretreated Barley Straw by additive xylanase and surfactants in enzymatic hydrolysis for acetone butanol ethanol fermentation
Bioresource Technology, 2015Co-Authors: Ming Yang, Junhua Zhang, Suvi Kuittinen, Jouko Vepsalainen, Pasi Soininen, Markku Keinanen, Ari PappinenAbstract:Abstract This study aims to improve enzymatic sugar production from dilute sulfuric acid-pretreated Barley Straw for acetone–butanol–ethanol (ABE) fermentation. The effects of additive xylanase and surfactants (polyethylene glycol [PEG] and Tween) in an enzymatic reaction system on Straw hydrolysis yields were investigated. By combined application of 2 g/100 g dry-matter (DM) xylanase and PEG 4000, the glucose yield was increased from 53.2% to 86.9% and the xylose yield was increased from 36.2% to 70.2%, which were considerably higher than results obtained with xylanase or surfactant alone. The ABE fermentation of enzymatic hydrolysate produced 10.8 g/L ABE, in which 7.9 g/L was butanol. The enhanced sugar production increased the ABE yield from 93.8 to 135.0 g/kg pretreated Straw. The combined application of xylanase and surfactants has a large potential to improve sugar production from Barley Straw pretreated with a mild acid and that the hydrolysate showed good fermentability in ABE production.
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co fermentation of hemicellulose and starch from Barley Straw and grain for efficient pentoses utilization in acetone butanol ethanol production
Bioresource Technology, 2015Co-Authors: Ming Yang, Junhua Zhang, Suvi Kuittinen, Jouko Vepsalainen, Markku Keinanen, Ari PappinenAbstract:Abstract This study aims to efficiently use hemicellulose-based biomass for ABE (acetone–butanol–ethanol) production by co-fermentation with starch-based biomass. Two processes were investigated: (I) co-fermentation of sugars derived from hemicellulose and starch in a mixture of Barley Straw and grain that was pretreated with dilute acid; (II) co-fermentation of Straw hemicellulosic hydrolysate and gelatinized grain slurry in which the Straw was pretreated with dilute acid. The two processes produced 11.3 and 13.5 g/L ABE that contains 7.4 and 7.8 g/L butanol, respectively. In process I, pretreatment with 1.0% H 2 SO 4 resulted in better ABE fermentability than with 1.5% H 2 SO 4 , but only 19% of pentoses were consumed. In process II, 95% of pentoses were utilized even in the hemicellulosic hydrolysate pretreated with more severe condition (1.5% H 2 SO 4 ). The results suggest that process II is more favorable for hemicellulosic biomass utilization, and it is also attractive for sustainable biofuel production due to great biomass availability.
Ajay Badhan - One of the best experts on this subject based on the ideXlab platform.
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new recombinant fibrolytic enzymes for improved in vitro ruminal fiber degradability of Barley Straw1
Journal of Animal Science, 2018Co-Authors: Gabriel O Ribeiro, Adrian Tsang, Ajay Badhan, Yuxi Wang, K A Beauchemin, Jiangli Huang, Wenzhu Yang, T A McallisterAbstract:This study used a high-throughput in vitro microassay, in vitro batch culture, and the Rumen Simulation Technique (RUSITEC) to screen recombinant fibrolytic enzymes for their ability to increase the ruminal fiber degradability of Barley Straw. Eleven different recombinant enzymes in combination with a crude mixture of rumen enzymes (50% recombinant enzyme:50% crude mixture of rumen enzymes) were compared with the crude mixture of rumen enzymes alone. In the microassay, all treatments were applied at 15 mg of protein load per gram Barley Straw glucan. Based on the microassay results, 1 recombinant endoglucanase [EGL7A, from the glycoside hydrolase (GH) family 7], 2 recombinant xylanases (XYL10A and XYL10C, from GH10), and a recombinant enzyme mixture were selected and compared with a crude mixture of fibrolytic enzymes from Aspergillus aculeatus for their ability to hydrolyze Barley Straw. For batch culture, enzymes were applied to Barley Straw at 2 dosages (100 and 500 µg of protein/g of substrate DM). All enzymes increased (P < 0.05) DM disappearance and total VFA production, but the mixture of recombinant enzymes was not superior to the use of a single recombinant enzyme. Based on positive results (P < 0.05) for total DM disappearance and VFA production in batch culture, 3 enzymes (EGL7A, XYL10A, and XYL10C) were selected and applied to Barley Straw at 500 µg of protein per gram for further assessment in RUSITECs fed a concentrate:Barley Straw diet (300:700 g/kg DM). In RUSITECs, the recombinant enzyme XYL10A increased (P < 0.05) Barley Straw DM, NDF, and ADF disappearance, whereas EGL7A and XYL10C had no effect. The enzymes selected based on the high-throughput in vitro microassay consistently increased Barley Straw degradation in ruminal batch culture, but not in the semicontinuous culture RUSITEC system.
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formulation of enzyme blends to maximize the hydrolysis of alkaline peroxide pretreated alfalfa hay and Barley Straw by rumen enzymes and commercial cellulases
BMC Biotechnology, 2014Co-Authors: Ajay Badhan, Yuxi Wang, Donald Patton, Justin PowlowskiAbstract:Efficient conversion of lignocellulosic biomass to fermentable sugars requires the synergistic action of multiple enzymes; consequently enzyme mixtures must be properly formulated for effective hydrolysis. The nature of an optimal enzyme blends depends on the type of pretreatment employed as well the characteristics of the substrate. In this study, statistical experimental design was used to develop mixtures of recombinant glycosyl hydrolases from thermophilic and anaerobic fungi that enhanced the digestion of alkaline peroxide treated alfalfa hay and Barley Straw by mixed rumen enzymes as well as commercial cellulases (Accelerase 1500, A1500; Accelerase XC, AXC). Combinations of feruloyl and acetyl xylan esterases (FAE1a; AXE16A_ASPNG), endoglucanase GH7 (EGL7A_THITE) and polygalacturonase (PGA28A_ASPNG) with rumen enzymes improved Straw digestion. Inclusion of pectinase (PGA28A_ASPNG), endoxylanase (XYN11A_THITE), feruloyl esterase (FAE1a) and β-glucosidase (E-BGLUC) with A1500 or endoglucanase GH7 (EGL7A_THITE) and β-xylosidase (E-BXSRB) with AXC increased glucose release from alfalfa hay. Glucose yield from Straw was improved when FAE1a and endoglucanase GH7 (EGL7A_THITE) were added to A1500, while FAE1a and AXE16A_ASPNG enhanced the activity of AXC on Straw. Xylose release from alfalfa hay was augmented by supplementing A1500 with E-BGLUC, or AXC with EGL7A_THITE and XYN11A_THITE. Adding arabinofuranosidase (ABF54B_ASPNG) and esterases (AXE16A_ASPNG; AXE16B_ASPNG) to A1500, or FAE1a and AXE16A_ASPNG to AXC enhanced xylose release from Barley Straw, a response confirmed in a scaled up assay. The efficacy of commercial enzyme mixtures as well as mixed enzymes from the rumen was improved through formulation with synergetic recombinant enzymes. This approach reliably identified supplemental enzymes that enhanced sugar release from alkaline pretreated alfalfa hay and Barley Straw.
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formulation of enzyme blends to maximize the hydrolysis of alkaline peroxide pretreated alfalfa hay and Barley Straw by rumen enzymes and commercial cellulases
BMC Biotechnology, 2014Co-Authors: Ajay Badhan, Robert J. Gruninger, Yuxi Wang, Donald Patton, Justin Powlowski, Adrian TsangAbstract:Background Efficient conversion of lignocellulosic biomass to fermentable sugars requires the synergistic action of multiple enzymes; consequently enzyme mixtures must be properly formulated for effective hydrolysis. The nature of an optimal enzyme blends depends on the type of pretreatment employed as well the characteristics of the substrate. In this study, statistical experimental design was used to develop mixtures of recombinant glycosyl hydrolases from thermophilic and anaerobic fungi that enhanced the digestion of alkaline peroxide treated alfalfa hay and Barley Straw by mixed rumen enzymes as well as commercial cellulases (Accelerase 1500, A1500; Accelerase XC, AXC).
Sirma Yegin - One of the best experts on this subject based on the ideXlab platform.
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valorization of egg shell as a detoxifying and buffering agent for efficient polymalic acid production by aureobasidium pullulans nrrl y 2311 1 from Barley Straw hydrolysate
Bioresource Technology, 2019Co-Authors: Sirma Yegin, Badal C Saha, Gregory J Kennedy, Timothy D LeathersAbstract:Abstract Stepwise formulation of a versatile and cost-effective medium based on Barley Straw hydrolysate and egg shell for efficient polymalic acid production by A. pullulans NRRL Y-2311-1 was carried out for the first time. The strain did not grow and produce polymalic acid when dilute acid pretreated Barley Straw hydrolysate (total fermentable sugars: 94.60 g/L; furfural: 1.01 g/L; hydroxymethylfurfural: 0.55 g/L; acetic acid: 5.06 g/L) was directly used in medium formulation without detoxification (e.g. charcoal pretreatment). When CaCO3 in the medium formulation was substituted with egg shell powder, efficient production of polymalic acid was achieved without a detoxification step. Utilization of 40 g/L of egg shell powder led to 43.54 g polymalic acid production per L with the productivity of 0.30 g/L/h and yield of 0.48 g/g. The bioprocess strategy used in this study can also be utilized for mass production of several other industrially important microbial organic acids and biomaterials.