Objectives: To engineer a small nonconding RNA anti41 to enhance nisin yield by inhibiting the expression of glnR in Lactococcus lactis F44.
Results: We constructed a screening library to determine appropriate artificial sRNAs and obtained a sRNA anti41 that can produce approximately three fold of the inhibitory effect on GlnR. Moreover, the transcription levels of the direct inhibitory targets of GlnR (glnP, glnQ, amtB, and glnK) were dramatically upregulated in the anti41 overexpression strain (F44-anti41), thereby confirming the inhibitory effect of anti41 on GlnR. In addition, anti41 overexpression improved the survival rate of cells by approximately three fold under acid stress, promoted cell growth, and increased nisin yield by 29.83%.
Conclusions: We were able to provide a novel strategy for the construction of robust high-producing industrial strains.
Keywords: Acid resistance; Artificial sRNA; GlnR; Lactococcus lactis; Nisin yield.