环境因素对PlnA诱导类植物乳杆菌产生细菌素效果的影响

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

摘要:

【目的】研究人工合成的PlnA (Plantaricin A)诱导类植物乳杆菌L-XM1细菌素合成的功能及环境条件对其诱导效果的影响。【方法】制备类植物乳杆菌L-XM1 Bac?培养物, 用人工合成的PlnA对其进行诱导, 确定PlnA在类植物乳杆菌L-XM1细菌素合成中的作用, 并通过比较不同温度、pH以及NaCl浓度、乙醇浓度条件下PlnA的诱导活性, 研究环境条件对PlnA诱导效果的影响。【结果】在不同温度及pH条件下, 自诱导肽PlnA的诱导活性有很大的差异, 较高的培养温度及pH有利于其诱导活性的发挥。不同浓度的NaCl对PlnA的诱导活性影响不大。乙醇可以减弱PlnA的诱导活性, 高浓度的乙醇完全抑制PlnA的诱导活性。6%乙醇对细菌素合成的抑制可以被700 μg/L的PlnA消除, 含有8%乙醇的培养基中, 恢复细菌素的合成需要浓度高达1 000 μg/L的PlnA。【结论】环境条件可以影响PlnA的诱导活性, 乙醇对细菌素合成的抑制可以通过增大PlnA的浓度消除。

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.