Construction of thermotolerant yeast expressing thermostable cellulase genes.
Kluyveromyces marxianus NBRC1777 was identified as a thermotolerant yeast and was developed as a host for the expression of thermostable cellulase genes. The previously isolated genes for thermostable endo-beta-1,4-glucanase, cellobiohydrolase, and beta-glucosidase were introduced into the chromosome of K. marxianus and successfully expressed under the control of high-expression promoters. The recombinant K. marxianus expressing cellulase genes became able to grow in synthetic medium containing cellobiose or carboxymethyl-cellulose as the single carbon source. Moreover, the recombinant strain produced 43.4 g/L ethanol from 10% cellobiose. These results suggest that K. marxianus may afford a useful host system, which may be applicable to the simultaneous saccharification and fermentation and the foundation of cellulose consolidated bioprocessing.
Hong
Jiong
J
Laboratory of Applied Microbiology, Research Institute of Natural Resources, Ishikawa Prefectural University, Nonoichi-cho, Ishikawa 921-8836, Japan.
Wang
Yonghong
Y
Kumagai
Hidehiko
H
Tamaki
Hisanori
H
D002475:Cellobiose / Q000378:metabolism; D002480:Cellulase / Q000235:genetics* / Q000378:metabolism*; D043366:Cellulose 1,4-beta-Cellobiosidase / Q000378:metabolism; D015825:Chromosomes, Fungal; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D015870:Gene Expression; D005800:Genes, Fungal; D006358:Hot Temperature; D007700:Kinetics; D007716:Kluyveromyces / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011995:Recombination, Genetic; D001617:beta-Glucosidase / Q000378:metabolism
D002475:Cellobiose; D000431:Ethanol; D001617:beta-Glucosidase; D002480:Cellulase; D043366:Cellulose 1,4-beta-Cellobiosidase