Effects of Fructose and Overexpression of Shock-Related Gene groL on Plantaricin Q7 Production.

The effects of fructose on plantaricin Q7 biosynthesis in Lactobacillus plantarum (L. plantarum) Q7 were investigated. Fructose induced and accelerated plantaricin Q7 production in the early stages of biosynthesis. Two-dimensional electrophoresis and quantitative real-time reverse transcriptase PCR (qRT-PCR) revealed that shock-related proteins were overexpressed in L. plantarum grown in MRS-fructose compared with cultures grown in MRS broth. A preheat-shock (PHS) treatment was used to overexpress shock-related proteins to enhance plantaricin Q7 production. The final plantaricin Q7 level reached 2873.08 IU/mL following PHS treatment, which was 23.36% higher than that obtained using a control strategy without PHS treatment. qRT-PCR analyses indicated that only groL was induced (by 10-fold) following PHS treatment. Evidently, groL plays a critical role in plantaricin Q7 biosynthesis. These results demonstrate that PHS treatment is an efficient approach to improving plantaricin Q7 production. The information obtained in this study may increase the amount of efficient antimicrobial peptide production using L. plantarum.