中文摘要：

从发酵大蒜中筛选到一株具有抑菌作用的菌株Br26,通过用不同蛋白酶处理判断该菌株是否为细菌素产生菌。随后,通过分析自身发酵上清液与其他乳酸菌对细菌素合成的影响,探讨该细菌素的诱导合成现象。结果表明：菌株Br26的发酵上清液经胃蛋白酶和木瓜蛋白酶处理后抑菌活性降低,确定该菌为细菌素产生菌,经16S r DNA鉴定为Weissella sp.Br26。Weissella sp.Br26在42℃、1/4 MRS培养时,细菌素抑菌活性消失,而当添加不同生长时期的发酵上清液时,抑菌活性显著增加,表明该细菌素可进行自我诱导。另一方面,Weissella sp.Br26与卷曲乳杆菌、瑞士乳杆菌、副干酪乳杆菌和肠膜明串珠菌的活菌共同培养后,发酵液p H值未有明显变化,但细菌素抑菌活性显著增加,表明细菌素的合成亦可受其他乳酸菌的诱导。综上,Weissella sp.Br26细菌素的合成是受自身发酵液及其他菌诱导调控的。

英文摘要：

The strain Br26 with antibacterial activity was screened from fermented garlic.Different proteases were selected to determine whether the strain is bacteriocin-producing bacterium.Subsequently,the induction efficiency of bacteriocin synthesis by the fermentation supernatant of Br26 alone and co-cultures with other lactic acid bacteria was determined.The results showed the inhibitory activity of the fermentation supernatant of Br26 decreased after treatment with pepsin and papain,respectively,suggesting that the antimicrobial substance is bacteriocin.The strain was identified as Weissella sp.Br26 by 16 S rDNA gene sequence homology analysis.The inhibitory activity disappeared when Br26 was cultured in 1/4MRS at 42 ℃;however,it was significantly increased after adding fermentation supernatants at different growth phases,indicating that bacteriocin biosynthesis can be self-induced.On the other hand,although there were no significant changes in the pH values of fermentation supernatants,bacteriocin activity of Br26 was significantly increased after co-culturing with Lactobacillus crispatus,Lactobacillus helveticus,Lactobacillus paracasei and Leuconostoc mesenteroides,indicating that the synthesis of bacteriocin can also be induced by other lactic acid bacteria.In summary,bacteriocin synthesis of Weissella sp.Br26 can be induced by itself and other lactic acid bacteria.