Effects of PlnA on bacteriocin production in Lactobacillus paraplantarum: influence of environmental factors

Abstract:

[Objective] Function of PlnA in bacteriocin production of Lactobacillus paraplantarum L-XM1 and the influences of environmental conditions on its inducing effect were studied. [Methods] The function of PlnA was determined by adding synthesis PlnA to Bac? cultures of L. paraplantarum L-XM1. Induction activity of PlnA was detected at different temperature, pH, NaCl and ethanol concentrations for investigating the effects of environmental conditions on PlnA. [Results] Variabilities for induction activity of PlnA were detected for different temperature and pH value, higher incubation temperature or relatively higher pH is helpful for its induction activity. No significant differences in PlnA induction activity were found among different concentrations of NaCl. The presence of ethanol was found to reduce the induction activity of PlnA, and at higher concentration of ethanol, its activity is inhibited. The inhibitory of bacteriocin production by 6% ethanol could be attenuated by simultaneously addition of high concentraion of PlnA (700 μg/L), while restoring bacteriocion production in medium containing 8% ethanol need up to 1 000 μg/L PlnA. [Conclusion] The induction effects of PlnA could be affected by environmental factors, the inhibition effects of bacteriocin synthesis by ethanol could be eliminated by increasing PlnA concentrations.