Cloning, sequencing and expression of a novel xylanase cDNA from a newly isolated Aspergillus awamori in Pichia pastoris

Abstract

A strain SH 2016, capable of producing xylanase, was isolated and identified as Aspergillus awamori, based on its physiological and biochemical characteristics as well as its ITS rDNA gene sequence
analysis. A xylanase gene of 591 bp was cloned from this newly isolated A. awamori and the ORF sequence predicted a protein of 196 amino acids with a molecular mass about 21 kDa. An expression plasmid carrying the gene under the control of the methanol regulated alcohol oxidase gene (AOX1)
promotor was introduced into Pichia pastoris, and xylanase gene was successfully expressed into the medium using methanol as inducer. Xylanase with 6 his tags was purified using Ni2+-NTA column. The
characteristics of purified xylanase were investigated.