Journal of Fundamentals of Renewable Energy and Applications
Open Access
ISSN: 2090-4541
+44 1300 500008
ISSN: 2090-4541
+44 1300 500008
Xin Song, Liwei Gao, Zhonghai Li, Chenqiang Xia and Yinbo Qu
Shandong University, China
Qilu University of Technology, China
Scientific Tracks Abstracts: J Fundam Renewable Energy App
Cellulolytic fungi Penicillium oxalicum produces diverse lignocellulolytic enzymes, and has been shown to be a promising cellulase producer. Given the dose-controlled or additive regulation of cellulase genes by the master regulator ClrB presented in P. oxalicum, and the synergistic transcriptional induction of cellulolytic genes in Bgl2-deficient background, we constructed two overexpression cassettes gpdA(p)::clrB::Ã?Â?creA-ptra and PDE_02864(p)::clrB::Ã?Â?bgl2-bar, in which the clrB overexpression cassettes confer creA or bgl2 flanking regions, respectively. These overexpression cassettes for clrB were transformed sequentially into the pyrG mutant of P. oxalicum strain M12. The double mutant MRE1 (gpdA(p)::clrB::Ã?Â?creA) and the quadruple mutant MRE2 (gpdA(p)::clrB::Ã?Â?creAPDE_ 02864(p)::clrB::Ã?Â?bgl2) were obtained, respectively and their cellulase expression abilities were separately evaluated on cellulose and wheat bran media. Although all these experiments were performed in flasks, both MRE1 and MRE2 mutants showed more cellulolytic and xylanolytic enzyme activities and secretion abilities than parental strain M12. We also observed a significant increase in the strain bearing the XlnRA871V allele (alanine-to-valine mutation) under cellulose conditions relative to the parental wild type strain 114-2. Thus, the overexpression cassette carrying PDE_02864-driven XlnRA871V using pyrG as selective marker was reconstructed and transformed into quadruple mutant MRE2, and might be feasible in further enhancing the cellulase expression. These data signify that the dose-controlled regulation mechanisms of the cellulolytic regulators are a promising strategy for cellulolytic fungi to develop enzyme hyper-producers via the reconstruction of expression regulation network (RERN) technology.
Xin Song has completed his PhD from Shandong University and Post-doctoral studies from Inha University School of Biological Engineering. He is the Professor of School of Life Science, Shandong University. He has published more than 30 papers in reputed journals and has 12 authorized patents.
Email: songx@sdu.edu.cn