δ-Integration of endo/exo-glucanase and β-glucosidase genes into the yeast chromosomes for direct conversion of cellulose to ethanol
1999; Elsevier BV; Volume: 25; Issue: 1-2 Linguagem: Inglês
10.1016/s0141-0229(99)00011-3
ISSN1879-0909
AutoresKwang Myung Cho, Young Je Yoo, Hyen Sam Kang,
Tópico(s)Polysaccharides and Plant Cell Walls
ResumoFor the direct conversion of cellulose to ethanol, recombinant yeast having a full set of genes for the cellulolytic enzymes was developed. Using the δ-sequences of the Ty1 retrotransposon as target sites for homologous recombination, heterologous genes of endo/exo-glucanase and β-glucosidase were integrated into the chromosomes of Saccharomyces cerevisiae. The number of both integrated genes was found to be approximately 44. This newly constructed yeast, S. cerevisiae L2612δGC, successfully expressed and secreted the cellulolytic enzymes. Expression levels of cellulolytic enzymes, cell growth, and ethanol production in cellulose-containing media were significantly increased in comparison with plasmid-based expression. Maintenance of the integrated genes was also perfect up to 50 generations even in nonselectable media.
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