Ethanol production from cellulosic materials using cellulase‐expressing yeast

Yanase, Shuhei; Yamada, R.; Kaneko, Shohei; Noda, Hideo; Hasunuma, Tomohisa; Tanaka, Tsutomu; Ogino, Chiaki; Fukuda, Hideki; Kondo, Akihiko

doi:10.1002/biot.200900291

Cited by 75 publications

(46 citation statements)

References 18 publications

(22 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Cellulase degrades glycosidic bonds of cellulose and is widely used for industrial purposes, such as fiber processing, food processing, and bioethanol production. [1][2][3][4][5][6] The complete degradation of cellulose requires the synergistic action of three types of cellulases, endo-1,4-b-D-glucanase (endoglucanase; EC 3.2.1.4), exo-1,4-b-D-glucanase (cellobiohydrolase; EC 3.2.1.91 and 3.2.1.176), and bglucosidase (EC 3.2.1.21). These cellulases and other enzymes that hydrolyze glycosidic bonds are collectively termed glycoside hydrolases (GH).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structure, activity, and stability of metagenome‐derived glycoside hydrolase family 9 endoglucanase with an N‐terminal Ig‐like domain

et al. 2015

View full text Add to dashboard Cite

A metagenome-derived glycoside hydrolase family 9 enzyme with an N-terminal immunoglobulin-like (Ig-like) domain, leaf-branch compost (LC)-CelG, was characterized and its crystal structure was determined. LC-CelG did not hydrolyze p-nitrophenyl cellobioside but hydrolyzed CMcellulose, indicating that it is endoglucanase. LC-CelG exhibited the highest activity at 70 C and >80% of the maximal activity at a broad pH range of 5-9. Its denaturation temperature was 81.4 C, indicating that LC-CelG is a thermostable enzyme. The structure of LC-CelG resembles those of CelD from Clostridium thermocellum (CtCelD), Cel9A from Alicyclobacillus acidocaldarius (AaCel9A), and cellobiohydrolase CbhA from C. thermocellum (CtCbhA), which show relatively low (29-31%) amino acid sequence identities to LC-CelG. Three acidic active site residues are conserved as Asp194, Asp197, and Glu558 in LC-CelG. Ten of the thirteen residues that form the substrate binding pocket of AaCel9A are conserved in LC-CelG. Removal of the Ig-like domain reduced the activity and stability of LC-CelG by 100-fold and 6.3 C, respectively. Removal of the Gln40-and Asp99-mediated interactions between the Ig-like and catalytic domains destabilized LC-CelG by 5.0 C without significantly affecting its activity. These results suggest that the Ig-like domain contributes to the stabilization of LC-CelG mainly due to the Gln40-and Asp99-mediated interactions. Because the LC-CelG derivative lacking the Ig-like domain accumulated in Escherichia coli cells mostly in an insoluble form and this derivative accumulated in a soluble form exhibited very weak activity, the Ig-like domain may be required to make the conformation of the active site functional and prevent aggregation of the catalytic domain.

show abstract

Section: Introductionmentioning

confidence: 99%

“…18 LC-CelG is composed of 577 amino acid residues and contains a putative signal peptide (Residues [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19] at the N-terminus. LC-CelG without this signal peptide consists of an N-terminal Ig-like domain (Residues 20-132) and a C-terminal catalytic domain (Residues 133-577).…”

Section: Introductionmentioning

confidence: 99%

Structure, activity, and stability of metagenome‐derived glycoside hydrolase family 9 endoglucanase with an N‐terminal Ig‐like domain

et al. 2015

View full text Add to dashboard Cite

show abstract

“…In the past decade, researchers used the first strategy to develop genetically engineered bacteria (Guedon et al, 2002;Zhou and Ingram, 2001) and fungi (Kotaka et al, 2008;Den Haan et al, 2007;Fujita et al, 2004;Fujita et al, 2002;Ribeiro et al, 2010;Yanase et al, 2010). Among them, Saccharomyces cerevisiae was a very attractive host because of its high ethanol productivity and tolerance .…”

Section: Introductionmentioning

confidence: 99%

Direct fermentation of amorphous cellulose to ethanol by engineered Saccharomyces cerevisiae coexpressing Trichoderma viride EG3 and BGL1

Yang¹,

Tang²,

Wang³

et al. 2014

J. Gen. Appl. Microbiol.

View full text Add to dashboard Cite

Direct ethanol fermentation from amorphous cellulose was achieved using an engineered industrial Saccharomyces cerevisiae strain. Two cellulase genes endoglucanase (eg3) and β-glucosidase (bgl1) were obtained from Trichoderma viride and integrated into the genome of S. cerevisiae. These two cellulases could be constitutively coexpressed and secreted by the recombinant strain S. cerevisiae-eb. The enzyme activities were analyzed in the culture supernatants, with the highest endoglucanase activity of 2.34 units/ml and β-glucosidase activity of 0.95 units/ml. The effects of pH, temperature and metal ions on enzyme activities were analyzed. The coexpression strain S. cerevisiae-eb could grow in carboxymethyl cellulose (CMC) and utilize it as the single carbon source. The 20 g/L CMC as a model substrate of amorphous cellulose was used in fermentation. The ethanol production reached 4.63 g/L in 24 h, with the conversion ratio of 64.2% compared with the theoretical concentration. This study demonstrated that the engineered industrial strain S. cerevisiae-eb could convert amorphous cellulose to ethanol simultaneously and achieve consolidated bioprocessing (CBP) directly.

show abstract

“…Expression of saccharolytic enzymes has been demonstrated in microorganisms with established genetic systems such as Saccharomyces cerevisiae (8,15,29,32), but the overall enzymatic activity has not rivaled that of natively cellulolytic organisms. Alternatively, metabolic engineering has produced highyield ethanol fermentation in model organisms that can be genetically manipulated (24,27,33).…”

mentioning

confidence: 99%

High Ethanol Titers from Cellulose by Using Metabolically Engineered Thermophilic, Anaerobic Microbes

Argyros¹,

Tripathi²,

Barrett³

et al. 2011

Appl Environ Microbiol

286

261

View full text Add to dashboard Cite

This work describes novel genetic tools for use in Clostridium thermocellum that allow creation of unmarked mutations while using a replicating plasmid. The strategy employed counter-selections developed from the native C. thermocellum hpt gene and the Thermoanaerobacterium saccharolyticum tdk gene and was used to delete the genes for both lactate dehydrogenase (Ldh) and phosphotransacetylase (Pta). The ⌬ldh ⌬pta mutant was evolved for 2,000 h, resulting in a stable strain with 40:1 ethanol selectivity and a 4.2-fold increase in ethanol yield over the wild-type strain. Ethanol production from cellulose was investigated with an engineered coculture of organic acid-deficient engineered strains of both C. thermocellum and T. saccharolyticum. Fermentation of 92 g/liter Avicel by this coculture resulted in 38 g/liter ethanol, with acetic and lactic acids below detection limits, in 146 h. These results demonstrate that ethanol production by thermophilic, cellulolytic microbes is amenable to substantial improvement by metabolic engineering.

show abstract

Ethanol production from cellulosic materials using cellulase‐expressing yeast

Cited by 75 publications

References 18 publications

Structure, activity, and stability of metagenome‐derived glycoside hydrolase family 9 endoglucanase with an N‐terminal Ig‐like domain

Structure, activity, and stability of metagenome‐derived glycoside hydrolase family 9 endoglucanase with an N‐terminal Ig‐like domain

Direct fermentation of amorphous cellulose to ethanol by engineered Saccharomyces cerevisiae coexpressing Trichoderma viride EG3 and BGL1

High Ethanol Titers from Cellulose by Using Metabolically Engineered Thermophilic, Anaerobic Microbes

Contact Info

Product

Resources

About