Production of specific-molecular-weight hyaluronan by metabolically engineered Bacillus subtilis 168

摘要

Low-molecular-weight hyaluronan (LMW-HA) has attracted much attention because of its many potential applications. Here, we efficiently produced specific LMW-HAs from sucrose in Bacillus subtilis. By coexpressing the identified committed genes (tuaD, gtaB, glmU, glmM, and glmS) and downregulating the glycolytic pathway, HA production was significantly increased from 1.01 g L-1 to 3.16 g L-1, with a molecular weight range of 1.40 x 10(6)-1.83 x 10(6) Da. When leech hyaluronidase was actively expressed after N-terminal engineering (1.62 x 10(6) U mL(-1)), the production of HA was substantially increased from 5.96 g L-1 to 19.38 g L-1. The level of hyaluronidase was rationally regulated with a ribosome-binding site engineering strategy, allowing the production of LMW-HAs with a molecular weight range of 2.20 x 10(3)-1.42 x 10(6) Da. Our results confirm that this strategy for the controllable expression of hyaluronidase, together with the optimization of the HA synthetic pathway, effectively produces specific LMW-HAs, and could also be used to produce other LMW polysaccharides. (C) 2016 International Metabolic Engineering Society. Published by Elsevier Inc. All rights reserved.