一株抑制产气荚膜梭菌的枯草芽孢杆菌BS-2特性

Characteristics of Bacillus subtilis BS-2 against Clostridium perfringens

摘要:

【背景】感染产气荚膜梭菌会引起动物坏死性肠炎，通常使用抗生素进行预防和治疗。随着我国饲料禁抗、养殖减抗的实施，寻找绿色微生态制剂及其代谢产物成为当前研究的热点。【目的】旨在研究前期筛选的一株抑制产气荚膜梭菌的枯草芽孢杆菌BS-2特性。【方法】检测了菌株生长曲线、代谢物质的抑菌特性及细菌素基因簇mRNA表达。【结果】枯草芽孢杆菌BS-2代谢物质对革兰氏阴性菌无抑制作用，而对革兰氏阳性菌具有较强的抑菌性能，并且对产气荚膜梭菌的抑菌性能在2-12 h内迅速增长，在12-24 h内抑菌性能较稳定；该抑菌性能不受胃蛋白酶、胰蛋白酶、蛋白酶K的影响，具有良好的热稳定性；进一步分析抑菌物质基因簇mRNA表达，发现枯草芽孢杆菌BS-2抑制产气荚膜梭菌的活性可能与表面活性素(surfactin)和美杀菌素(mersacidin)表达有关。【结论】枯草芽孢杆菌BS-2对产气荚膜梭菌具有较强的抑制作用，可能通过抑菌物质surfactin和mersacidin表达发挥作用。

关键词:枯草芽孢杆菌;产气荚膜梭菌;代谢物质;表面活性素;美杀菌素

Abstract:

[Background] Infection with Clostridium perfringens causes necrotizing enteritis in animals, which is commonly treated by antibiotics. With the limitation of antibiotics in feed and husbandry in China, probiotics and its metabolites have become the focus of current research. [Objective] This study was conducted to reveal the properties of B. subtilis BS-2 against Clostridium perfringens. [Methods] The growth curve of B. subtilis BS-2, the antimicrobial properties of its metabolites and the mRNA levels of bacteriocin gene cluster were detected. [Results] The metabolites of B. subtilis BS-2 had no inhibitory effect on Gram-negative bacteria, whereas they had strong activity against Gram-positive bacteria. The activity of the strain against C. perfringens increased rapidly within 2–12 h and remained stable within 12–24 h. The antibacterial properties of the metabolites were not affected by pepsin, trypsin or protease K, which demonstrated good thermal stability. The mRNA levels of bacteriocin gene cluster showed that the inhibitory activity of B. subtilis BS-2 against C. perfringens was related to the expression of surfactin and mersacidin. [Conclusion] B. subtilis BS-2 may inhibit C. perfringens by regulating the expression of surfactin and mersacidin.

Key words:Bacillus subtilis;Clostridium perfringens;metabolites;surfactin;mersacidin