产细菌素乳酸菌的筛选及其发酵特性

从传统发酵制品中分离出60株乳酸菌,在排除有机酸及过氧化氢的干扰后,从中筛选出抑菌活性较高的菌株P-319,经常规生理生化实验,鉴定该菌株为短乳杆菌。其发酵上清液经胰蛋白酶和木瓜蛋白酶处理后抑菌活性丧失;对其抑菌谱的测定表明,其能抑制革兰氏阳性菌和革兰氏阴性菌的生长,但对霉菌和酵母菌没有任何抑制作用。产细菌素的发酵过程测定结果表明,该菌株在MRS培养基中30℃培养24 h时,抑菌活性达到最高。

Selection and characterization of bacteriocin-producing Lactobacillus

The 60 Lactobacillus strains were isolated from fermented food in which one strain P-319 having high antimicrobial activity was selected and identified as Lactobacillus brevis.The culture supernatant of strain P-319 showed antimicrobial activity on the indicator strains growth when excluding the effect of organic acids and hydrogen peroxide,but lost antimicrobial activity in the presence of trypsin and papain.Furthermore,the supernatant have a broad inhibitory spectrum against microorganisms,including gram-positive bacteria and gram-negative bacteria.In contrast,yeast or mold can't be inhibited.Maximum inhibitory activity was recorded in MRS broth after 24 h at 30 ℃.