The amyR-deletion strain of Aspergillus niger CICC2462 is a suitable host strain to express secreted protein with a low background. Issue 1 (December 2016)

• Record Type: Journal Article
• Authors: Zhang, Hui; Wang, Shuang; Zhang, Xiang; Ji, Wei; Song, Fuping; Zhao, Yue; Li, Jie
• Is Part Of: Microbial cell factories. Volume 15:Issue 1(2016)
• Page Start: 1
• Page End: 11
• Publication Date: 2016-12
• Subjects: Aspergillus niger -- amyR -- Regulation -- Proteomics -- Transcriptome; Microbial biotechnology -- Periodicals; Recombinant proteins -- Synthesis -- Periodicals; 660.62
• DOI: 10.1186/s12934-016-0463-1
• Languages: English
• ISSNs: 1475-2859

Abstract

Abstract Background The filamentous fungusAspergillus niger is widely exploited as an important expression host for industrial production. The glucoamylase high-producing strainA. niger CICC2462 has been used as a host strain for the establishment of a secretion expression system. It expresses recombinant xylanase, mannase and asparaginase at a high level, but some high secretory background proteins in these recombinant strains still remain, such as alpha-amylase and alpha-glucosidase; lead to a low-purity of fermentation products. The aim was to construct anA. niger host strain with a low background of protein secretion. Results The transcription factoramyR was deleted inA. niger CICC2462, and the results from enzyme activity assays and SDS-PAGE analysis showed that the glucoamylase and amylase activities of the ∆amyR strains were significantly lower than those of the wild-type strain. High-throughput RNA-sequencing and shotgun LC–MS/MS proteomic technology analysis demonstrated that the expression of amylolytic enzymes was decreased at both the transcriptional and translational levels in the ∆amyR strain. Interestingly, the ∆amyR strain growth rate better than the wild-type strain. Conclusions Our findings clearly indicated that the ∆amyR strain ofA. niger CICC2462 can be used as a host strain with a low background of protein secretion.