Cellulase kinetics as a function of cellulose pretreatment

Bommarius, Andreas S.; Katona, Adrian; Cheben, Sean E.; Patel, Arpit S.; Ragauskas, Arthur J.; Knudson, Kristina; Pu, Yunqiao

doi:10.1016/j.ymben.2008.06.008

Cited by 175 publications

(122 citation statements)

References 27 publications

(35 reference statements)

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“…The end product of the cellulose hydrolysis by endo-and exocellulases is cellobiose. This molecule is a glucose disaccharide having multiple properties: it is (i) a repressor of the cellulolytic machinery (44) and (ii) an inhibitor of the cellulases (45). A model for cellulose deconstruction suggests that the cellobiose concentration can increase rapidly during the cellulolysis and inhibit cellulase activity.…”

Section: Discussionmentioning

confidence: 99%

Phylogenetic Distribution of Potential Cellulases in Bacteria

Berlemont

Martiny

2013

Appl Environ Microbiol

262

233

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Many microorganisms contain cellulases that are important for plant cell wall degradation and overall soil ecosystem functioning. At present, we have extensive biochemical knowledge of cellulases but little is known about the phylogenetic distribution of these enzymes. To address this, we analyzed the distribution of 21,985 genes encoding proteins related to cellulose utilization in 5,123 sequenced bacterial genomes. First, we identified the distribution of glycoside hydrolases involved in cellulose utilization and synthesis at different taxonomic levels, from the phylum to the strain. Cellulose degradation/utilization capabilities appeared in nearly all major groups and resulted in strains displaying various enzyme gene combinations. Potential cellulose degraders, having both cellulases and ␤-glucosidases, constituted 24% of all genomes whereas potential opportunistic strains, having ␤-glucosidases only, accounted for 56%. Finally, 20% of the bacteria have no relevant enzymes and do not rely on cellulose utilization. The latter group was primarily connected to specific bacterial lifestyles like autotrophy and parasitism. Cellulose degraders, as well as opportunists, have multiple enzymes with similar functions. However, the potential degraders systematically harbor about twice more ␤-glucosidases than their potential opportunistic relatives. Although scattered, the distribution of functional types, in bacterial lineages, is not random but mostly follows a Brownian motion evolution model. Degraders form clusters of relatives at the species level, whereas opportunists are clustered at the genus level. This information can form a mechanistic basis for the linking of changes in microbial community composition to soil ecosystem processes.

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Section: Discussionmentioning

confidence: 99%

Phylogenetic Distribution of Potential Cellulases in Bacteria

Berlemont

Martiny

2013

Appl Environ Microbiol

262

233

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“…The lignocellulosic material has to be pretreated to allow higher conversion of cellulose, which is consumed during enzymatic hydrolysis to produce glucose and xylose that are finally fermented to produce ethanol (Sun and Cheng, 2002;Bommarius et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Composition, Characterization and Enzymatic Hydrolysis of Pretreated Sugar Cane Bagasse

Guilherme

Dantas

Santos

et al. 2015

Braz. J. Chem. Eng.

160

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-Glucose production from sugarcane bagasse was investigated. Sugarcane bagasse was pretreated by four different methods: combined acid and alkaline, combined hydrothermal and alkaline, alkaline, and peroxide pretreatment. The raw material and the solid fraction of the pretreated bagasse were characterized according to the composition, SEM, X-ray and FTIR analysis. Glucose production after enzymatic hydrolysis of the pretreated bagasse was also evaluated. All these results were used to develop relationships between these parameters to understand better and improve this process. The results showed that the alkaline pretreatment, using sodium hydroxide, was able to reduce the amount of lignin in the sugarcane bagasse, leading to a better performance in glucose production after the pretreatment process and enzymatic hydrolysis. A good xylose production was also observed.

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“…Mansfield et al [21] detailed the existing substrate factors limiting the hydrolysis at different structural levels. Several factors, such as crystallinity [13,22,23] and degree of polymerization [24] have been proved to have an influence on the initial hydrolysis rate of cellulose. However, few studies have been devoted to the morphological changes occurring during the enzymatic hydrolysis.…”

Section: Introductionmentioning

confidence: 99%

Evolution and impact of cellulose architecture during enzymatic hydrolysis by fungal cellulases

Chauve¹,

Barré²,

Tapin-Lingua³

et al. 2013

ABB

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The enzymatic hydrolysis of cellulose is still considered as a main limiting step of the biological production of biofuels from ligno-cellulosic biomass. Glycoside hydrolases from Trichoderma reesei are currently used to produce fermentable glucose units from degradation of cellulose packed in a complex assembly of cellulose microfibrils. The present work describes the structural evolution of two prototypical samples of cellulose (a micro-crystalline cellulose and a bleached sulfite pulp) over 5 length scale orders of magnitude. The results were obtained through wide angle, small angle and ultra-small angles synchrotron X-ray scattering, completed by Small Angle Neutron Scattering and particle size analyzers. These structural evolutions were followed as a function of enzymatic conversion. The results show that whereas there is no change at the nanometer scale, drastic changes occur at micron. The observed decrease of the size of the cellulose particles is accompanied by a smoothing of the crystalline surfaces that can be explained by a two-step mechanism of the enzymatic hydrolysis.

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Cellulase kinetics as a function of cellulose pretreatment

Cited by 175 publications

References 27 publications

Phylogenetic Distribution of Potential Cellulases in Bacteria

Phylogenetic Distribution of Potential Cellulases in Bacteria

Evaluation of Composition, Characterization and Enzymatic Hydrolysis of Pretreated Sugar Cane Bagasse

Evolution and impact of cellulose architecture during enzymatic hydrolysis by fungal cellulases

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