Construction of a Robust Sphingomonas sp. Strain for Welan Gum Production via the Expression of Global Transcriptional Regulator IrrE.

ABSTRACT: Welan gum is a widely used microbial polysaccharide produced by Sphingomonas sp. However, an important factor hindering the expansion of its production is the maladaptation of strain to fermentation conditions. In this work, the global transcriptional regulator gene irre was selected as a stress-resistant element. And it was integrated into the site of the genomic carotene synthesis key enzyme gene crtB to construct a robust carotenoid-free welan gum producing strain. Fermentation with the recombinant strain effectively reduced the ethanol consumption and pigment content in the product. The tolerance temperature increased by 10°C without the need for controlling the pH. Under this fermentation condition, welan gum concentration could still reach 20.26 ± 0.25 g/L, which

SUBMITTER: Liu X 

PROVIDER: S-EPMC7338795 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature