Constitutive Expression of Chimeric Transcription Factors Enables Cellulase Synthesis under Non‐Inducing Conditions in Penicillium oxalicum. Issue 11 (18th September 2017)

• Record Type: Journal Article
• Authors: Gao, Liwei; Xia, Chengqiang; Xu, Jiadi; Li, Zhonghai; Yu, Lele; Liu, Guodong; Song, Xin; Qu, Yinbo
• Is Part Of: Biotechnology journal. Volume 12:Issue 11(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-09-18
• Subjects: cellulase -- chimeric transcription factor -- hemicellulase -- Penicillium oxalicum; Biotechnology -- Periodicals; 660.605
• DOI: 10.1002/biot.201700119
• Languages: English
• ISSNs: 1860-6768

Abstract

Abstract : Industrial production of cellulase by filamentous fungi is largely dependent on cellulose, which serves as a natural inducer of cellulase expression. However, insoluble cellulose is unfavorable to submerged fermentation and thus limits the production level of cellulase. The possibility of cellulase production under non‐inducing conditions is explored in Penicillium oxalicum by overexpressing two chimeric transcription factors. The chimeric transcription factors contain the DNA binding domain of cellulase transcriptional activator ClrB linked to the C‐terminal sequences of XlnR A871V, a constitutively active mutant of hemicellulase transcriptional activator. The obtained recombinant mutants exhibited dramatically improved basal production of cellulase, which was not observed with the overexpression of intact ClrB. When cultivated in a complex cellulosic medium, one of these mutants, OE‐CX C ‐S‐1, displayed a 7.3‐fold increase in cellulase production (2.8 U mL −1 ) relative to the parent strain. The results demonstrate that the dependence of cellulase synthesis on cellulose could be reduced by the overexpression of artificially designed chimeric transcription factors, and offers a potential strategy to engineer fungal strains for improving cellulase production. Abstract : Industrial production of cellulase by filamentous fungi is largely dependent on insoluble cellulose, which limits the production level of cellulase. In this study, the authors showed that overexpression of chimeric transcription factors with designed combination of DNA binding and transcriptional activation domains enabled cellulase production under cellulose‐free conditions in Penicillium oxalicum . The work offers a potential strategy to engineer fungal strains for improving cellulase production.