Enhancing the expression of Aspergillus niger ß-mannanase in Pichia pastoris by coexpression of protein disulfide isomerase

Authors

XIAOLING CHEN
BO ZHOU
MENG XU
ZHIQING HUANG
GANG JIA
JIAYUN QIAO
GUANGMANG LIU

DOI

10.3906/biy-1408-33

Abstract

A gene encoding ß-mannanase from Aspergillus niger GIM3.452 was amplified and inserted into a pPIC9K vector. The resulting recombinant plasmid, pPIC9K-MAN, was transformed into Pichia pastoris GS115. One strain (GSKM-1) having the highest ß-mannanase activity of 26.6 U/mL was obtained. In order to increase the secretion of ß-mannanase in P. pastoris, we constructed a double recombinant yeast and made it coexpress protein disulfide isomerase. One strain (GSKZ\alphaM2) with the highest ß-mannanase activity of 40 U/mL was then obtained and used to optimize expression conditions. When the GSKZ\alphaM2 strain was induced under the optimized conditions (methanol concentration 1.5%, induction time 7 days), ß-mannanase activity reached 222.8 U/mL. SDS-PAGE and deglycosylation assays demonstrated that the recombinant A. niger ß-mannanase, a glycosylated protein with an apparent molecular weight of 45 kDa, was secreted into the culture medium. It displayed maximum activity at pH 4.4 and 60 °C, and it was stable in a pH range of 2.4-8.0 and at a temperature of 60 °C or below. Our results suggested that coexpression chaperones could improve the yield of ß-mannanase.

Keywords

Aspergillus niger, ß-mannanase, Pichia pastoris, protein disulfide isomerase, expression condition optimization

First Page

312

Last Page

319

Recommended Citation

CHEN, XIAOLING; ZHOU, BO; XU, MENG; HUANG, ZHIQING; JIA, GANG; QIAO, JIAYUN; and LIU, GUANGMANG (2015) "Enhancing the expression of Aspergillus niger ß-mannanase in Pichia pastoris by coexpression of protein disulfide isomerase," Turkish Journal of Biology: Vol. 39: No. 2, Article 17. https://doi.org/10.3906/biy-1408-33
Available at: https://journals.tubitak.gov.tr/biology/vol39/iss2/17