Effects of a novel transcription factor BglR from Penicillium decumbens on cellulase production

Abstract:

[Objective] Penicillium decumbens is an important filamentous fungus that efficiently secrets cellulases. The biosynthesis and secretion of these cellulases are regulated on transcription levels. In order to further study the mechanism of transcriptional regulation of cellulases encoding genes and construct industrial strains with high cellulases production, [Methods] We identified a transcription regulator BglR (PDE-01706) from P. decumbens 114-2 by comparing gene expression profiles under different carbon sources condition. This transcription regulator shares a 59% sequence identity with the zinc finger protein Pc20g04780 from Penicillium chrysogenum. P. decumbens ΔbglR-1 knockout strain was constructed with homologous double crossover recombination. The phenotype of this strain was investigated, including its hyphal growth, protein secretion level, cellulase secretion level and extracellular pH level. [Results] It was shown that the deletion of the transcription factor BglR in P. decumbens ΔbglR-1 leads to an increase of extracellular β-glucosidase activity by 40%, and a lowered filter paper activity, endoglucanases and xylanase level. [Conclusion] From these results it is proposed that BglR plays a major role in the regulation of cellulase production of P. decumbens.