Coexpression of rumen microbial beta-glucanase and xylanase genes in Lactobacillus reuteri

Abstract

The aim of this study was to clone and coexpress two rumen fibrolytic enzyme genes in Lactobacillus reuteri. The ability of the genetically modified strain to degrade beta-glucan and xylan was evaluated. The Fibrobacter succinogenes beta-glucanase (1,3-1,4-beta-D-glucan 4-glucanohydrolase [EC 3.2.1.73]) gene and the Neocallimastix patriciarum xylanase gene, xynCDBFV, were constructed to coexpress and secrete under control of the Lactococcus lactis lacA promoter and its secretion signal and then transformed into L. reuteri Pg4, a strain isolated from the gastrointestinal tract of broiler chickens. The transformed L. reuteri strain acquired the capacity to break down soluble beta-glucan and xylan. The introduction of the recombinant plasmids and production of beta-glucanase and xylanase did not affect cell growth. To the best of our knowledge, this is the first report of coexpression of rumen microbial fibrolytic enzyme genes in L. reuteri.