Factors involved in the response to change of agitation rate during cellulase production fromPenicillium decumbensJUA10-1

• DOI: 10.1007/s10295-013-1305-3
• Publication Date: 2013-07-01T14:18:16Z
• Authors: Mingyu Wang; Didi He; Ya Liang; Kuimei Liu; Baojie Jiang; Fangzhong Wang; Shaoli Hou; Xu Fang
• Keywords: Fungal Proteins; 0301 basic medicine; 03 medical and health sciences; Adenosine Triphosphate; Bioreactors; Cellulase; Transcription, Genetic; Penicillium; Down-Regulation; Biomass; Gene Expression Regulation, Bacterial; Transcription Factors

AbstractImprovement of agitation is a commonly used approach for the optimization of fermentation processes. In this report, the response to improving agitation rate from 150 to 250 rpm on cellulase production from Penicillium decumbens JUA10-1 was investigated. It was shown that the production of all the major components of the cellulase mixture increased following improved agitation. Further investigations showed that at least three factors are involved in this improvement: the improved biomass accumulation, proportion of active/mature cellulases, and cellulase transcription level. The transcription levels of the cellulase repressing transcription factor ace1 and the cellulase activating transcription factor xlnR, however, both declined when a higher agitation was applied. These observations, along with our analysis of the carbon catabolite repressor CreA, lead to the suggestion that the molecular mechanism underlying improved cellulase transcription is the competition of two concurrent effects following improved agitation: CreA-mediated derepression induced by the downregulation of ace1, and CreA-mediated deactivation induced by the downregulation of xlnR.