布氏乳杆菌细菌素BSX01对金黄色葡萄球菌及其生物被膜形成的影响

Effect of Lactobacillus buchneri Bacteriocin BSX01 on Staphylococcus aureus and Its Biofilm Formation

为评估布氏乳杆菌所产细菌素在食品工业中的应用潜力,通过培养布氏乳杆菌获得具有抑制金黄色葡萄球菌的抑菌活性物质,经纯化后鉴定其相对分子质量大小与抑菌特性,并对抑制金黄色葡萄球菌生物被膜的形成进行探讨。结果发现,布氏乳杆菌在37℃MRS培养基中培养至20 h后进入稳定期,在26 h时对金黄色葡萄球菌的抑菌圈直径达峰值,为(26.36±0.86)mm。通过ÄKTA pure系统串联Superdex 30 Increase纯化后,鉴定得到抑菌活性物质(BSX01)的相对分子质量为773.56,对多种蛋白酶敏感,推测为Ⅰ类细菌素。在pH 10(2 h)和121℃(30 min)处理后,BSX01仍具有较好的抑菌活性,最小抑菌质量浓度(MIC)仅为12.50μg/mL。此外,BSX01在1/2 MIC时可有效降低金黄色葡萄球菌生物被膜的形成,在2 MIC时能够完全抑制生物被膜的形成。基于上述结果,布氏乳杆菌产生的细菌素BSX01是食品工业中的潜在生物防腐剂和抑制食源性致病菌生物被膜形成的有效候选品。

This study aimed to evaluate the potential application of bacteriocins produced by Lactobacillus buchneri(L.buchneri)in the food industry.The substance with antibacterial activity against Staphylococcus aureus(S.aureus)was obtained through the cultivation of L.buchneri.After purification,its molecular weight and antibacterial characteristics were identified,and the inhibition of S.aureus biofilm formation was explored.The results showed that L.buchneri reached a stable period after cultivation in MRS medium at 37℃for 20 h,and the diameter of inhibition zone against S.aureus reached the peak value of(26.36±0.86)mm at 26 h.After purification by ÄKTA pure system in tandem with Superdex 30 Increase,the molecular weight of the antibacterial active substance(BSX01)was identified as 773.56,which was sensitive to a variety of proteases and presumed to be a class I bacteriocin.BSX01 retained good inhibitory activity even after treatment at pH 10(2 h)and 121℃(30 min),with a minimum inhibitory concentration(MIC)of only 12.50μg/mL.In addition,BSX01 effectively reduced the formation of S.aureus biofilm at 1/2MIC,and completely inhibited the formation of S.aureus biofilm at 2MIC.Based on these results,the bacteriocin BSX01 produced by L.buchneri is demonstrated to be a potential bio-preservative and an effective candidate for inhibiting the formation of biofilm by foodborne pathogenic bacteria in the food industry.