关键词: 特异腐质霉, 纤维素酶, T-DNA随机插入, 锌指蛋白

Abstract: Humicola insolens holds a high capacity for neutral and thermostable cellulases secretion that has industrial applications promising, like biomass energy, feed and textile industry. In this study, we isolated a mutant T53 with enhanced cellulase and hemicellulase activities from a transfer DNA (T-DNA)-tagged mutant library of H. insolens that was developed before. The FPase, endoglucanase, cellobiohydrolase, β-glucosidase, and xylanase activities of T53, measured at the end of fermentation, were 40%, 60%, 90%, 10%, 60% higher than those of the wild-type strain, respectively. The result of SDS-PAGE showed that the secretion of extracellular proteins, especially cellulases and hemicellulases of T53 strain was significantly higher than that of wild type strain. The sequence flanking the T-DNA insertions in T53 was isolated and a putative zinc finger protein encoding gene potentially involved in cellulase and hemicellulase expression was identified. This study laid an important foundation for revealing the molecular mechanism of cellulases high-yielding in mutant T53, which would also enrich our understanding of the genetics background of H. insolens.

Key words: Humicola insolens, cellulases, T-DNA insertional mutagenesis, zinc finger protein