1
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Strategies for improving hydrolytic efficiency of crude multienzyme extracts in mushroom processing. Heliyon 2022; 8:e11312. [DOI: 10.1016/j.heliyon.2022.e11312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Revised: 06/24/2022] [Accepted: 10/26/2022] [Indexed: 11/09/2022] Open
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2
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Varshavskiy AA, Naumova EI. Fluorimetry Method for Assaying Cellobiohydrolase Activity in Digestive Tracts of Small Herbivorous Mammals. BIOL BULL+ 2022. [DOI: 10.1134/s106235902205020x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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3
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Lu M, Li J, Han L, Xiao W. An aggregated understanding of cellulase adsorption and hydrolysis for ball-milled cellulose. BIORESOURCE TECHNOLOGY 2019; 273:1-7. [PMID: 30368157 DOI: 10.1016/j.biortech.2018.10.037] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 10/13/2018] [Accepted: 10/15/2018] [Indexed: 05/22/2023]
Abstract
This study evaluated the effects of physicochemical properties of a series of ball-milled cellulose on cellulase adsorption and glucose yield. The relationship between cellulase adsorption and initial hydrolysis rate was also discussed. We found that hydrophobicity and surface charge are the key factors affecting cellulase adsorption on ball-milled cellulose. The results demonstrated that glucose yield had a positive correlation with specific surface area, while showed a negative correlation with particle size, degree of polymerization and crystallinity. Among these properties, specific surface area and crystallinity are the key factors affecting glucose yield. As ball milling progressed, cellulose showed lower enzyme adsorption capacity/amount of bound enzyme during initial stage of hydrolysis, but had higher initial hydrolysis rate. The enhanced rate is attributed to the fact that the amorphous region produced by ball milling reduces the free energy required for decrystallization thus increases the catalytic efficiency of the bound enzyme.
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Affiliation(s)
- Minsheng Lu
- Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Beijing 100083, PR China.
| | - Junbao Li
- Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Beijing 100083, PR China.
| | - Lujia Han
- Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Beijing 100083, PR China.
| | - Weihua Xiao
- Laboratory of Biomass and Bioprocessing Engineering, College of Engineering, China Agricultural University, Beijing 100083, PR China.
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4
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Karlapudi AP, Venkateswarulu TC, Srirama K, Dirisala VR, Kamarajugadda BP, Kota RK, Kodali VP. Purification and Lignocellulolytic Potential of Cellulase from Newly Isolated Acinetobacter indicus KTCV2 Strain. IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY, TRANSACTIONS A: SCIENCE 2018. [DOI: 10.1007/s40995-018-0600-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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5
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Badino SF, Christensen SJ, Kari J, Windahl MS, Hvidt S, Borch K, Westh P. Exo-exo synergy between Cel6A and Cel7A fromHypocrea jecorina: Role of carbohydrate binding module and the endo-lytic character of the enzymes. Biotechnol Bioeng 2017; 114:1639-1647. [DOI: 10.1002/bit.26276] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 02/17/2017] [Accepted: 02/21/2017] [Indexed: 01/08/2023]
Affiliation(s)
- Silke F. Badino
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
| | - Stefan J. Christensen
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
| | - Jeppe Kari
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
| | - Michael S. Windahl
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
- Novozymes A/S; Bagsvaerd Denmark
| | - Søren Hvidt
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
| | | | - Peter Westh
- Research Unit for Functional Biomaterials; Department of Science and Environment; INM; Roskilde University; 1 Universitetsvej, Build. 28C, DK-4000 Roskilde Denmark
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6
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Hamid SBA, Islam MM, Das R. Cellulase biocatalysis: key influencing factors and mode of action. CELLULOSE 2015; 22:2157-2182. [DOI: 10.1007/s10570-015-0672-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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7
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Li Y, Qi B, Wan Y. Inhibitory effect of vanillin on cellulase activity in hydrolysis of cellulosic biomass. BIORESOURCE TECHNOLOGY 2014; 167:324-330. [PMID: 24997375 DOI: 10.1016/j.biortech.2014.06.035] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 06/07/2014] [Accepted: 06/09/2014] [Indexed: 06/03/2023]
Abstract
Pretreatment of lignocellulosic material produces a wide variety of inhibitory compounds, which strongly inhibit the following enzymatic hydrolysis of cellulosic biomass. Vanillin is a kind of phenolics derived from degradation of lignin. The effect of vanillin on cellulase activity for the hydrolysis of cellulose was investigated in detail. The results clearly showed that vanillin can reversibly and non-competitively inhibit the cellulase activity at appropriate concentrations and the value of IC50 was estimated to be 30 g/L. The inhibition kinetics of cellulase by vanillin was studied using HCH-1 model and inhibition constants were determined. Moreover, investigation of three compounds with similar structure of vanillin on cellulase activity demonstrated that aldehyde group and phenolic hydroxyl groups of vanillin had inhibitory effect on cellulase. These results provide valuable and detailed information for understanding the inhibition of lignin derived phenolics on cellulase.
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Affiliation(s)
- Yun Li
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China; University of Chinese Academy of Sciences, Beijing 100049, PR China
| | - Benkun Qi
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China
| | - Yinhua Wan
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, PR China.
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8
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Newman RH, Vaidya AA, Sohel MI, Jack MW. Optimizing the enzyme loading and incubation time in enzymatic hydrolysis of lignocellulosic substrates. BIORESOURCE TECHNOLOGY 2013; 129:33-8. [PMID: 23232221 DOI: 10.1016/j.biortech.2012.11.028] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2012] [Revised: 11/05/2012] [Accepted: 11/05/2012] [Indexed: 05/14/2023]
Abstract
A mathematical model for costing enzymatic hydrolysis of lignocellulosics is presented. This model is based on three variable parameters describing substrate characteristics and three unit costs for substrate, enzymes and incubation. The model is used to minimize the cost of fermentable sugars, as intermediate products on the route to ethanol or other biorefinery products, by calculating optimized values of enzyme loading and incubation time. This approach allows comparisons between substrates, with processing conditions optimized independently for each substrate. Steam-exploded pine wood was hydrolyzed in order to test the theoretical relationship between sugar yield and processing conditions.
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Affiliation(s)
- Roger H Newman
- Scion, Private Bag 3020, Rotorua Mail Centre, Rotorua 3046, New Zealand.
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9
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Newman RH, Vaidya AA, Campion SH. A mathematical model for the inhibitory effects of lignin in enzymatic hydrolysis of lignocellulosics. BIORESOURCE TECHNOLOGY 2013; 130:757-762. [PMID: 23340076 DOI: 10.1016/j.biortech.2012.12.122] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2012] [Revised: 11/09/2012] [Accepted: 12/16/2012] [Indexed: 06/01/2023]
Abstract
A new model for enzymatic hydrolysis of lignocellulosic biomass distinguishes causal influences from enzyme deactivation and restrictions on the accessibility of cellulose. It focuses on calculating the amount of unreacted cellulose at cessation of enzyme activity, unlike existing models that were constructed for calculating the time dependence of conversion. There are three adjustable parameters: (1) 'occluded cellulose' is defined as cellulose that cannot be hydrolysed regardless of enzyme loading or incubation time, (2) a 'characteristic enzyme loading' is sufficient to hydrolyse half of the non-occluded cellulose, (3) a 'mechanism index' measures deviations from first-order kinetics. This model was used to predict that the optimal incubation temperature is lower for lignocellulosics than for pure cellulose. For steam-exploded pine wood after 96h incubation, occluded cellulose was 24% and 26% at 30°C and 50°C, and the characteristic enzyme loadings were 10 and 18FPU/g substrate, respectively.
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Affiliation(s)
- Roger H Newman
- Scion, Private Bag 3020, Rotorua Mail Centre, Rotorua 3046, New Zealand.
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10
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Liu HQ, Feng Y, Zhao DQ, Jiang JX. Influence of cellulose content on the enzyme activity in the saccharification digests of furfural residues. ASIA-PAC J CHEM ENG 2012. [DOI: 10.1002/apj.1644] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- H. Q. Liu
- Department of Chemistry and Chemical Engineering; Beijing Forestry University; Beijing; 100083; China
| | - Y. Feng
- Department of Chemistry and Chemical Engineering; Beijing Forestry University; Beijing; 100083; China
| | - D. Q. Zhao
- Department of Chemistry and Chemical Engineering; Beijing Forestry University; Beijing; 100083; China
| | - J. X. Jiang
- Department of Chemistry and Chemical Engineering; Beijing Forestry University; Beijing; 100083; China
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11
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Bezerra RMF, Dias AA, Fraga I, Pereira AN. Cellulose hydrolysis by cellobiohydrolase Cel7A shows mixed hyperbolic product inhibition. Appl Biochem Biotechnol 2011; 165:178-89. [PMID: 21499786 DOI: 10.1007/s12010-011-9242-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2011] [Accepted: 04/04/2011] [Indexed: 10/18/2022]
Abstract
In order to establish which are the contribution of linear (total), hyperbolic (partial) or parabolic inhibitions by cellobiose, and also a special case of substrate inhibition, the kinetics of cellobiohydrolase Cel7A obtained from Trichoderma reesei was investigated. Values of kinetic parameters were estimated employing integrated forms of Michaelis-Menten equations through the use of non-linear regression, and criteria for selecting inhibition models are discussed. With cellobiose added at the beginning of the reaction, it was found that cellulose hydrolysis follows a kinetic model, which takes into account a mixed hyperbolic inhibition, by cellobiose with the following parameter values: K (m) 5.0 mM, K (ic) 0.029 mM, K (iu) 1.1 mM, k (cat) 3.6 h(-1) and k (cat') 0.2 h(-1). Cellulose hydrolysis without initial cellobiose added also follows the same inhibition model with similar values (4.7, 0.029 and 1.5 mM and 3.2 and 0.2 h(-1), respectively). According to Akaike information criterion, more complex models that take into account substrate and parabolic inhibitions do not increase the modulation performance of cellulose hydrolysis.
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Affiliation(s)
- Rui Manuel Furtado Bezerra
- CITAB - Departamento de Biologia e Ambiente, Universidade de Trás-os-Montes e Alto Douro, Apartado 1013, 5001-801, Vila Real, Portugal.
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12
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Praestgaard E, Elmerdahl J, Murphy L, Nymand S, McFarland KC, Borch K, Westh P. A kinetic model for the burst phase of processive cellulases. FEBS J 2011; 278:1547-60. [DOI: 10.1111/j.1742-4658.2011.08078.x] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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13
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Wang Z, Feng H. Fractal kinetic analysis of the enzymatic saccharification of cellulose under different conditions. BIORESOURCE TECHNOLOGY 2010; 101:7995-8000. [PMID: 20542686 DOI: 10.1016/j.biortech.2010.05.056] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2010] [Revised: 05/12/2010] [Accepted: 05/17/2010] [Indexed: 05/29/2023]
Abstract
Fractal kinetic analysis has been applied for the kinetics of enzymatic saccharification of cellulose. Based on the first order cellulose degradation kinetic, a fractal kinetic model with two parameters (rate coefficient and fractal exponent) has been developed. The model fits very well with the experimental data of enzymatic saccharification of cellulose under different conditions, including cellulase loading, nature of substrate, hydrolysis temperature, and addition of nonionic surfactant or polymer in the reaction medium. It indicates that the complex kinetics of enzymatic saccharification of cellulose can be described with the fractal kinetic model. The model exhibits that an addition of nonionic surfactant or polymer increases the rate coefficient and decreases the fractal exponent at the same time. A nonionic surfactant or polymer aqueous solution may be a potential medium engineering method for enzymatic saccharification of cellulose in biofuel industry.
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Affiliation(s)
- Zhilong Wang
- School of Pharmacy, Shanghai Jiao Tong University, Shanghai 200240, PR China.
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14
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Olsen SN, Lumby E, McFarland K, Borch K, Westh P. Kinetics of Enzymatic High-Solid Hydrolysis of Lignocellulosic Biomass Studied by Calorimetry. Appl Biochem Biotechnol 2010; 163:626-35. [DOI: 10.1007/s12010-010-9068-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Accepted: 08/13/2010] [Indexed: 10/19/2022]
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15
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Hall M, Bansal P, Lee JH, Realff MJ, Bommarius AS. Cellulose crystallinity - a key predictor of the enzymatic hydrolysis rate. FEBS J 2010; 277:1571-82. [DOI: 10.1111/j.1742-4658.2010.07585.x] [Citation(s) in RCA: 408] [Impact Index Per Article: 29.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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16
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Bansal P, Hall M, Realff MJ, Lee JH, Bommarius AS. Modeling cellulase kinetics on lignocellulosic substrates. Biotechnol Adv 2009; 27:833-848. [DOI: 10.1016/j.biotechadv.2009.06.005] [Citation(s) in RCA: 302] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 06/19/2009] [Accepted: 06/20/2009] [Indexed: 11/15/2022]
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17
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Kumar R, Wyman CE. Does change in accessibility with conversion depend on both the substrate and pretreatment technology? BIORESOURCE TECHNOLOGY 2009; 100:4193-202. [PMID: 19398329 DOI: 10.1016/j.biortech.2008.11.058] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2008] [Revised: 11/11/2008] [Accepted: 11/20/2008] [Indexed: 05/17/2023]
Abstract
The accessibility of cellulase and xylanase enzymes to glucan and xylan, respectively, and its change with conversion were measured for pure Avicel glucan and poplar solids that had been pretreated by ammonia fiber expansion (AFEX), ammonia recycled percolation (ARP), dilute acid, and lime. Avicel and pretreated solids were digested to various degrees by cellulase together with beta-glucosidase enzymes and then cleaned of residual protein via a biological method using Protease. Glucan accessibility was determined by purified CBHI (Cel7A) adsorption at 4 degrees C, and 4 and 24 h hydrolysis yields were determined for solids loading containing equal amounts of glucan (1.0% w/v) and lignin (1.0% w/v), in two separate sets of experiments. Consistent with our previous study and in contrast to some in the literature, little change in glucan accessibility was observed with conversion for Avicel, but glucan and xylan accessibility for real biomass varied with the type of pretreatment. For example, AFEX pretreated solids showed a negligible change in glucan accessibility for conversion up to 90%, although xylan accessibility seemed to decline first and then remained constant. On the other hand, a substantial decline in glucan and xylan accessibility with conversion was observed for lime pretreated poplar solids, as shown by initial hydrolysis rates. Yet, an increase in CBHI adsorption with conversion for lime pretreated poplar solids suggested the opposite trend, possibly due to increased lignin exposure and/or reduced effectiveness of adsorbed enzyme.
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Affiliation(s)
- Rajeev Kumar
- Thayer School of Engineering, Dartmouth College, New Hampshire 03755, USA
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18
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Ronkvist ÅM, Xie W, Lu W, Gross RA. Cutinase-Catalyzed Hydrolysis of Poly(ethylene terephthalate). Macromolecules 2009. [DOI: 10.1021/ma9005318] [Citation(s) in RCA: 341] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Åsa M. Ronkvist
- NSF I/URC for Biocatalysis and Bioprocessing of Macromolecules, Department of Chemical and Biological Sciences, Polytechnic University, Six Metrotech Center, Brooklyn, New York 11201
| | - Wenchun Xie
- NSF I/URC for Biocatalysis and Bioprocessing of Macromolecules, Department of Chemical and Biological Sciences, Polytechnic University, Six Metrotech Center, Brooklyn, New York 11201
| | - Wenhua Lu
- NSF I/URC for Biocatalysis and Bioprocessing of Macromolecules, Department of Chemical and Biological Sciences, Polytechnic University, Six Metrotech Center, Brooklyn, New York 11201
| | - Richard A. Gross
- NSF I/URC for Biocatalysis and Bioprocessing of Macromolecules, Department of Chemical and Biological Sciences, Polytechnic University, Six Metrotech Center, Brooklyn, New York 11201
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19
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Gianinetti A. A theoretical framework for β-glucan degradation during barley malting. Theory Biosci 2009; 128:97-108. [DOI: 10.1007/s12064-008-0055-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2008] [Accepted: 12/12/2008] [Indexed: 12/01/2022]
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20
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Ma A, Hu Q, Qu Y, Bai Z, Liu W, Zhuang G. The enzymatic hydrolysis rate of cellulose decreases with irreversible adsorption of cellobiohydrolase I. Enzyme Microb Technol 2008. [DOI: 10.1016/j.enzmictec.2008.02.009] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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21
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Abstract
The enzymatic kinetics of glycoside hydrolase family 7 cellobiohydrolase (Cel7A) towards highly crystalline celluloses at the solid-liquid interface was evaluated by applying the novel concept of surface density (rho) of the enzyme, which is defined as the amount of adsorbed enzyme divided by the maximum amount of adsorbed enzyme. When the adsorption levels of Trichoderma viride Cel7A on cellulose I(alpha) from Cladophora and cellulose I(beta) from Halocynthia were compared, the maximum adsorption of the enzyme on cellulose I(beta) was approximately 1.5 times higher than that on cellulose I(alpha), although the rate of cellobiose production from cellulose I(beta) was lower than that from cellulose I(alpha). This indicates that the specific activity (k) of Cel7A adsorbed on cellulose I(alpha) is higher than that of Cel7A adsorbed on cellulose I(beta). When k was plotted versus rho, a dramatic decrease of the specific activity was observed with the increase of surface density (rho-value), suggesting that overcrowding of enzyme molecules on a cellulose surface lowers their activity. An apparent difference of the specific activity was observed between crystalline polymorphs, i.e. the specific activity for cellulose I(alpha) was almost twice that for cellulose I(beta). When cellulose I(alpha) was converted to cellulose I(beta) by hydrothermal treatment, the specific activity of Cel7A decreased and became similar to that of native cellulose I(beta) at the same rho-value. These results indicate that the hydrolytic activity (rate) of bound Cel7A depends on the nature of the crystalline cellulose polymorph, and an analysis that takes surface density into account is an effective means to evaluate cellulase kinetics at a solid-liquid interface.
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Affiliation(s)
- Kiyohiko Igarashi
- Department of Biomaterials Sciences, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan
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22
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Hildén L, Väljamäe P, Johansson G. Surface character of pulp fibres studied using endoglucanases. J Biotechnol 2005; 118:386-97. [PMID: 15950308 DOI: 10.1016/j.jbiotec.2005.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2004] [Revised: 05/02/2005] [Accepted: 05/04/2005] [Indexed: 11/27/2022]
Abstract
The endoglucanase Cel5A from Trichoderma reesei and an endoglucanase from Aspergillus sp. (Novozym 476 from Novozyme A/S) were evaluated as probes for the surface properties of soft- and hardwood chemical pulp fibres. The hydrolysis time curves were in accordance with a two-phase degradation model described by a biexponential function. The kinetic parameters corresponding to the amount of fast and slow degraded parts of the substrate correlated to tensile index, relative bonded area and z-strength of the paper. All paper properties showing a correlation with enzyme kinetic parameters were related to fibre-fibre interactions. Fluorescence labelling of the reducing end groups in pulp fibres followed by enzyme treatment indicated that the fast substrate class corresponds to the population of "loose" cellulose chain ends not tightly associated with the bulk cellulose. The correlation between the parameters of enzyme kinetics and mechanical properties of the paper produced from the corresponding pulp found in this study should allow a rapid evaluation of the raw fibre material used in paper making process.
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Affiliation(s)
- Lars Hildén
- WURC, Department of Wood Science, Swedish University of Agricultural Sciences, Box 7008, 750 07 Uppsala, Sweden.
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23
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Zhang YHP, Lynd LR. Toward an aggregated understanding of enzymatic hydrolysis of cellulose: noncomplexed cellulase systems. Biotechnol Bioeng 2005; 88:797-824. [PMID: 15538721 DOI: 10.1002/bit.20282] [Citation(s) in RCA: 883] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Information pertaining to enzymatic hydrolysis of cellulose by noncomplexed cellulase enzyme systems is reviewed with a particular emphasis on development of aggregated understanding incorporating substrate features in addition to concentration and multiple cellulase components. Topics considered include properties of cellulose, adsorption, cellulose hydrolysis, and quantitative models. A classification scheme is proposed for quantitative models for enzymatic hydrolysis of cellulose based on the number of solubilizing activities and substrate state variables included. We suggest that it is timely to revisit and reinvigorate functional modeling of cellulose hydrolysis, and that this would be highly beneficial if not necessary in order to bring to bear the large volume of information available on cellulase components on the primary applications that motivate interest in the subject.
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Coluccio ML, Barbani N, Bianchini A, Silvestri D, Mauri R. Transport Properties of EVAl-Starch-α Amylase Membranes. Biomacromolecules 2005; 6:1389-96. [PMID: 15877357 DOI: 10.1021/bm049321j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated the influence of various physicochemical parameters on the morphology and time-porosity formation of membranes composed of ethylene-vinyl alcohol, starch, and alpha-amylase. In particular, we determined that (1) it is possible to obtain a membrane with desired porosity by phase inversion in an appropriate water-ethanol mixture and (2) the enzymatic bioerosion is controlled by the amount of alpha-amylase present in the blend. Although no experiments involving drugs were carried out, the delivery properties of the film were determined by measuring the Darcy permeability, the effective diffusivity, and the mean reaction rate of the membranes, relating them to the modality of membrane preparation, the amount of enzyme present within the membrane, and the incubation time of the samples in a buffer solution. Simple theoretical models of the delivery properties of the membranes were developed, leading to predictions that were in good agreement with the experimental results.
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Affiliation(s)
- M L Coluccio
- Department of Chemical Engineering, DICCISM, University of Pisa, Via Diotisalvi 2, 56126 Pisa, Italy
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25
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Vardakou M, Katapodis P, Topakas E, Kekos D, Macris B, Christakopoulos P. Synergy between enzymes involved in the degradation of insoluble wheat flour arabinoxylan. INNOV FOOD SCI EMERG 2004. [DOI: 10.1016/s1466-8564(03)00044-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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26
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Aguado J, Romero MD, Moncó G, Rodríguez L. Enzymatic hydrolysis of wheat straw: Kinetic analysis. ACTA ACUST UNITED AC 2004. [DOI: 10.1002/abio.370130105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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27
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Vardakou M, Katapodis P, Samiotaki M, Kekos D, Panayotou G, Christakopoulos P. Mode of action of family 10 and 11 endoxylanases on water-unextractable arabinoxylan. Int J Biol Macromol 2003; 33:129-34. [PMID: 14599595 DOI: 10.1016/s0141-8130(03)00077-1] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Microbial endo-beta-1,4-xylanases (EXs, EC 3.2.1.8) belonging to glycanase families 10 and 11 differ in their action on water-unextractable arabinoxylan (WU-AX). WU-AX was incubated with different levels of a Thermoascus aurantiacus family 10 and a Sporotrichum thermophile family 11 endoxylanases. At 10 g l(-1) arabinoxylan, enzyme concentrations (KE values) needed to obtain half-maximal hydrolysis rates (V(max) values) were 4.4 nM for the xylanase from T. aurantiacus and 7.1 nM for the xylanase from S. thermophile. Determination of Vmax/KE revealed that the family 10 enzyme hydrolysed two times more efficiently WU-AX than the family 11 enzyme. Molecular weights of the products formed were assessed and separation of feruloyl-oligosaccharides was achieved by anion-exchange and size-exclusion chromatography (SEC). The main difference between the feruloylated products by xylanases of family 10 and 11 concerned the length of the products containing feruloyl-arabinosyl substitution. The xylanase from T. aurantiacus liberated from WU-AX a feruloyl arabinoxylodisaccharide (FAX2) as the shortest feruloylated fragment in contrast with the enzyme from S. thermophile, which liberated a feruloyl arabinoxylotrisaccharide (FAX3). These results indicated that different factors govern WU-AX breakdown by the two endoxylanases.
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Affiliation(s)
- Maria Vardakou
- Biotechnology Laboratory, Chemical Engineering Department, National Technical University of Athens, 5 Iroon Polytechniou Str., Zografou Campus, 15700 Athens, Greece
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28
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Väljamäe P, Kipper K, Pettersson G, Johansson G. Synergistic cellulose hydrolysis can be described in terms of fractal-like kinetics. Biotechnol Bioeng 2003; 84:254-7. [PMID: 12966583 DOI: 10.1002/bit.10775] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
A fractal-like kinetics model was used to describe the synergistic hydrolysis of bacterial cellulose by Trichoderma reesei cellulases. The synergistic action of intact cellobiohydrolase Cel7A and endoglucanase Cel5A at low enzyme-to-substrate ratios showed an apparent substrate inhibition consistent with a case where two-dimensional (2-D) surface diffusion of the cellobiohydrolase is rate-limiting. The action of Cel7A core and Cel5A was instead consistent with a three-dimensional (3-D) diffusion-based mode of action. The synergistic action of intact Cel7A was far superior to that of the core at a high enzyme-to-substrate ratio, but this effect was gradually reduced at lower enzyme-to-substrate ratios. The apparent fractal kinetics exponent h obtained by nonlinear fit of hydrolysis data to the fractal-like kinetics analogue of a first-order reaction was a useful empirical parameter for assessing the rate retardation and its dependence on the reaction conditions.
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Affiliation(s)
- Priit Väljamäe
- Institute of Molecular and Cell Biology, University of Tartu, Vanemuise 46-138, Tartu 51010, Estonia
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29
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Lynd LR, Weimer PJ, van Zyl WH, Pretorius IS. Microbial cellulose utilization: fundamentals and biotechnology. Microbiol Mol Biol Rev 2002; 66:506-77, table of contents. [PMID: 12209002 PMCID: PMC120791 DOI: 10.1128/mmbr.66.3.506-577.2002] [Citation(s) in RCA: 2307] [Impact Index Per Article: 104.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Fundamental features of microbial cellulose utilization are examined at successively higher levels of aggregation encompassing the structure and composition of cellulosic biomass, taxonomic diversity, cellulase enzyme systems, molecular biology of cellulase enzymes, physiology of cellulolytic microorganisms, ecological aspects of cellulase-degrading communities, and rate-limiting factors in nature. The methodological basis for studying microbial cellulose utilization is considered relative to quantification of cells and enzymes in the presence of solid substrates as well as apparatus and analysis for cellulose-grown continuous cultures. Quantitative description of cellulose hydrolysis is addressed with respect to adsorption of cellulase enzymes, rates of enzymatic hydrolysis, bioenergetics of microbial cellulose utilization, kinetics of microbial cellulose utilization, and contrasting features compared to soluble substrate kinetics. A biological perspective on processing cellulosic biomass is presented, including features of pretreated substrates and alternative process configurations. Organism development is considered for "consolidated bioprocessing" (CBP), in which the production of cellulolytic enzymes, hydrolysis of biomass, and fermentation of resulting sugars to desired products occur in one step. Two organism development strategies for CBP are examined: (i) improve product yield and tolerance in microorganisms able to utilize cellulose, or (ii) express a heterologous system for cellulose hydrolysis and utilization in microorganisms that exhibit high product yield and tolerance. A concluding discussion identifies unresolved issues pertaining to microbial cellulose utilization, suggests approaches by which such issues might be resolved, and contrasts a microbially oriented cellulose hydrolysis paradigm to the more conventional enzymatically oriented paradigm in both fundamental and applied contexts.
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Affiliation(s)
- Lee R Lynd
- Chemical and Biochemical Engineering, Thayer School of Engineering and Department of Biological Sciences, Dartmouth College, Hanover, New Hampshire 03755, USA.
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30
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Tzafriri AR, Bercovier M, Parnas H. Reaction diffusion model of the enzymatic erosion of insoluble fibrillar matrices. Biophys J 2002; 83:776-93. [PMID: 12124264 PMCID: PMC1302186 DOI: 10.1016/s0006-3495(02)75208-9] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Predicting the time course of in vivo biodegradation is a key issue in the design of an increasing number of biomedical applications such as sutures, tissue analogs and drug-delivery devices. The design of such biodegradable devices is hampered by the absence of quantitative models for the enzymatic erosion of solid protein matrices. In this work, we derive and simulate a reaction diffusion model for the enzymatic erosion of fibrillar gels that successfully reproduces the main qualitative features of this process. A key aspect of the proposed model is the incorporation of steric hindrance into the standard Michaelis-Menten scheme for enzyme kinetics. In the limit of instantaneous diffusion, the model equations are analogous to the standard equations for enzymatic degradation in solution. Invoking this analogy, the total quasi-steady-state approximation is used to derive approximate analytical solutions that are valid for a wide range of in vitro conditions. Using these analytical approximations, an experimental-theoretical method is derived to unambiguously estimate all the kinetic model parameters. Moreover, the analytical approximations correctly describe the characteristic hyperbolic dependence of the erosion rate on enzyme concentration and the zero-order erosion of thin fibers. For definiteness, the analysis of published experimental results of enzymatic degradation of fibrillar collagen is demonstrated, and the role of diffusion in these experiments is elucidated.
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Affiliation(s)
- Abraham R Tzafriri
- School of Computer Science and Engineering, Department of Neurobiology, The Hebrew University, Jerusalem 91904, Israel.
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31
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Gregg DJ, Saddler JN. Factors affecting cellulose hydrolysis and the potential of enzyme recycle to enhance the efficiency of an integrated wood to ethanol process. Biotechnol Bioeng 2000; 51:375-83. [DOI: 10.1002/(sici)1097-0290(19960820)51:4<375::aid-bit1>3.0.co;2-f] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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32
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Movagarnejad K, Sohrabi M, Kaghazchi T, Vahabzadeh F. A model for the rate of enzymatic hydrolysis of cellulose in heterogeneous solid–liquid systems. Biochem Eng J 2000. [DOI: 10.1016/s1369-703x(99)00049-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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33
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Abstract
Nonlinear kinetics are commonly observed in the enzymatic hydrolysis of cellulose. This nonlinearity could be explained by any or all of the following three factors: enzyme inactivation, product inhibition, or substrate heterogeneity. In this study, four different approaches were applied to test the above hypotheses using two Thermomonospora fusca endocellulases, E2 and E5. The lack of stimulation of cellulase activity by beta-glucosidase rules out the possibility of product inhibition as a cause of the observed nonlinearity. The results from the other three approaches all provide strong evidence against enzyme inactivation and strong evidence for substrate heterogeneity as the cause of the nonlinear kinetics. The most direct evidence for substrate heterogeneity is that pretreatment of swollen cellulose with either E2cd or E5cd gave a product that was hydrolyzed at a much (3- to 4-fold) slower rate than untreated swollen cellulose even though the initial treatment degraded only 15-18% of the substrate. Furthermore, the activation energy of E2 catalyzed hydrolysis of swollen cellulose increased from 10 kcal/mol for the initial rate to 29 kcal/mol for hydrolysis after 24% digestion.
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Affiliation(s)
- S Zhang
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14853, USA
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34
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Himmel ME, Ruth MF, Wyman CE. Cellulase for commodity products from cellulosic biomass. Curr Opin Biotechnol 1999; 10:358-64. [PMID: 10449322 DOI: 10.1016/s0958-1669(99)80065-2] [Citation(s) in RCA: 219] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
A vital objective for second millennium biotechnology will be the enzymatic conversion of renewable cellulosic biomass to inexpensive fermentable sugars; new and more efficient fermentation processes will convert this biological 'currency' to a variety of commodity products. Although early strides will be made using process development and engineering disciplines, mid-term and longer advances must rely heavily on insight gained through protein and metabolic engineering technologies. These challenging goals can be met most effectively by the full integration of academic, federal, and industrial efforts in teams that develop and apply new fundamental knowledge to key cost drivers.
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Affiliation(s)
- ME Himmel
- National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, CO 80401, USA.
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35
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Scandola M, Focarete ML, Frisoni G. Simple Kinetic Model for the Heterogeneous Enzymatic Hydrolysis of Natural Poly(3-hydroxybutyrate). Macromolecules 1998. [DOI: 10.1021/ma980137y] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Mariastella Scandola
- University of Bologna, Department of Chemistry “G. Ciamician” and Centro di Studio per la Fisica delle Macromolecole del CNR, via Selmi 2, 40126 Bologna, Italy
| | - Maria Letizia Focarete
- University of Bologna, Department of Chemistry “G. Ciamician” and Centro di Studio per la Fisica delle Macromolecole del CNR, via Selmi 2, 40126 Bologna, Italy
| | - Giovanna Frisoni
- University of Bologna, Department of Chemistry “G. Ciamician” and Centro di Studio per la Fisica delle Macromolecole del CNR, via Selmi 2, 40126 Bologna, Italy
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36
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Galas E, Pyc R, Romanowska I. Hydrolysis and transformation of cellulose withAspergillus niger IBT-90 enzymes. ACTA ACUST UNITED AC 1997. [DOI: 10.1002/abio.370170410] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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37
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Parajó JC, Alonso JL, Santos V. Development of a generalized phenomenological model describing the kinetics of the enzymatic hydrolysis of NaOH-treated pine wood. Appl Biochem Biotechnol 1996; 56:289-99. [PMID: 8984901 DOI: 10.1007/bf02786959] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Pinus pinaster wood samples were treated during 3 h with alkaline solutions (containing 1, 5.5, or 10 weight percent NaOH) at 100, 115, or 130 degrees C using liquor/wood ratios of 6, 8, or 10 g/g. The solid residues obtained in treatments were used as substrates for enzymatic hydrolysis. In the hydrolysis assays, the reaction time (in the range 0-48 h) was considered as an operational variable. The cellulose conversion achieved at the end of assays were highest for samples pretreated at high temperature and high alkali concentration using low liquor/wood ratios. The experimental results obtained in each hydrolysis trial were fitted to an empirical model based on the assumption that the cellulose contained in substrates was composed by two fractions having different susceptibility to hydrolysis. The kinetic parameters obtained for the various experiments performed were correlated with the operational variables by means of empirical, statistically significant equations, which provided a generalized interpretation of the process.
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Affiliation(s)
- J C Parajó
- Department of Chemical Engineering, University of Vigo (Campus Orense), Spain
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38
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Sild V, Ståhlberg J, Pettersson G, Johansson G. Effect of potential binding site overlap to binding of cellulase to cellulose: a two-dimensional simulation. FEBS Lett 1996; 378:51-6. [PMID: 8549801 DOI: 10.1016/0014-5793(95)01420-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A computer simulation model for the binding of ligands to a totally anisotropic surface (infinite two-dimensional square lattice) with overlapping binding sites has been developed. The validity of the simulation has been proven by comparison with cases where the correct results are known. The simulation of kinetics shows that when the lattice is close to saturation, the true equilibrium state is reached extremely slowly due to a lot of rearranging of the ligands on the lattice. Based on these findings, the terms 'apparent saturation' and 'apparent maximum coverage' have been introduced and defined. The largest discrepancies between 'apparent maximum coverage' and the theoretically predicted value were observed for ligands of large size and/or irregular shape. As an example, the model has been applied to describe the binding of cellobiohydrolase-I core to Avicel. A formula for calculation of the intrinsic binding constant, maximal binding capacity and specific surface of cellulose from real binding data has been derived.
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Affiliation(s)
- V Sild
- Institute of Molecular and Cell Biology, University of Tartu, Estonia
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39
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South C, Hogsett D, Lynd L. Modeling simultaneous saccharification and fermentation of lignocellulose to ethanol in batch and continuous reactors. Enzyme Microb Technol 1995. [DOI: 10.1016/0141-0229(94)00016-k] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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40
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Parajó J, Alonso J, Santos V. Delignification and Swelling of Eucalpytus Wood Ahead of Enzymatic Hydrolysis of the Cellulosic Fraction. Process Biochem 1995. [DOI: 10.1016/0032-9592(94)00063-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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41
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Duff SJB, Moritz JW, Andersen KL. Simultaneous hydrolysis and fermentation of pulp mill primary clarifier sludge. CAN J CHEM ENG 1994. [DOI: 10.1002/cjce.5450720611] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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42
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Scott CD, Davison BH, Scott TC, Woodward J, Dees C, Rothrock DS. An advanced bioprocessing concept for the conversion of waste paper to ethanol. Appl Biochem Biotechnol 1994. [DOI: 10.1007/bf02941836] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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43
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Schurz J, Zipper P, Lenz J. Structural Studies on Polymers as Prerequisites for Degradation. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 1993. [DOI: 10.1080/10601329308021249] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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44
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45
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Nidetzky B, Steiner W. A new approach for modeling cellulase-cellulose adsorption and the kinetics of the enzymatic hydrolysis of microcrystalline cellulose. Biotechnol Bioeng 1993; 42:469-79. [DOI: 10.1002/bit.260420410] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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46
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Coupled saccharification and fermentation of pre-treated Eucalyptus wood: a simple kinetic model. World J Microbiol Biotechnol 1993; 9:313-8. [PMID: 24420033 DOI: 10.1007/bf00383070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 12/07/1992] [Accepted: 12/18/1992] [Indexed: 10/26/2022]
Abstract
Coupled saccharification and fermentation of Eucalyptus globulus wood, pre-treated by acid hydrolysis and sodium hypochlorite, was carried out in two column reactors: one for enzymatic hydrolysis of the substrate at 50°C and the other for fermentation of sugars with calcium alginate-immobilized Saccharomyces cerevisiae at 30°C. A buffered solution containing cellulases at pH 4.8 was recycled through both reactors. The maximum yields were about 0.26 g ethanol per g of substrate. The results were reproduced reasonably well using a simple kinetic model consisting of two successive pseudo-first-order reactions.
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47
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Philippidis GP, Spindler DD, Wyman CE. Mathematical modeling of cellulose conversion to ethanol by the simultaneous saccharification and fermentation process. Appl Biochem Biotechnol 1992. [DOI: 10.1007/bf02920577] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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48
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Galbe M, Zacchi G. Simulation of ethanol production processes based on enzymatic hydrolysis of lignocellulosic materials using aspen plus. Appl Biochem Biotechnol 1992. [DOI: 10.1007/bf02920536] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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49
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Kim DW, Kim TS, Jeong YK, Lee JK. Adsorption kinetics and behaviors of cellulase components on microcrystalline cellulose. ACTA ACUST UNITED AC 1992. [DOI: 10.1016/0922-338x(92)90138-k] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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50
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Brown RF, Holtzapple MT. A comparison of the Michaelis-Menten and HCH-1 models. Biotechnol Bioeng 1990; 36:1151-4. [DOI: 10.1002/bit.260361110] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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