植物乳杆菌C8-1产类细菌素的初步研究

Preliminary characterization of bacteriocin-like substance formed by Lactobacillus plantarum C8-1

从发酵2周的泡菜中分离到66株乳杆菌,以其中4株乳杆菌作为出发菌株进行紫外诱变处理得到一株产类细菌素的突变株C8-1。基于细胞形态、生理生化和16S rDNA测序数据,菌株C8-1被鉴定为植物乳杆菌(Lactobacillus plantarum)。菌株C8-1所产的类细菌素具有较宽的抑菌谱,能够抑制大肠杆菌和金黄色葡萄球菌等多种食品腐败菌和致病菌;有较好的热稳定性,在4℃冷藏5 d和-20℃冷冻5d以及60,80,100℃和121℃分别加热15 min,活性损失均不超过6%;且抑菌活性随pH值增大逐步降低,当pH≥6时,抑菌活性消失,对胃蛋白酶、木瓜蛋白酶耐受性较强,对胰蛋白酶较为敏感。这些数据表明,产类细菌素的植物乳杆菌C8-1在食品加工中具有进一步地潜在应用价值。

Among 66 isolates of Lactobacillus from traditional Chinese vegetables fermented for two weeks, four isolates were induced by UV light for producing bacteriocin. From these four lactobacilli strains, the mutant C8-1 was proved to produce proteins able to have antibacterial activity . Strain C8-1 was further identified as LactobaciUus plantarum according to its cell morphology, physiological-biochemistry and 16S rDNA data. Bacteriocin-like substance produced by strain C8-1 had a wide antibacterial spectrum which inhibited food spoiled and pathogenic bacteria. It showed good stability within a wide range of temperatures. When refrigerated at 4℃ or frozen at -20 ℃ for 5d as well as treated at 60℃, 80 ℃, 100 ℃ or 121 ℃ for 15min, the activity loss of the bacteriocin was less than 6%. Its antibacterial activity decreased with gradually evaluated pH, and disappeared when pH was higher than 6. The bacteriocin was resistant to pepsin and papain, but highly sensitive to trypsin. The present information shows that Lactobacillus plantarum C8-1 should be very potential for use as biological con- trol agent in food processing and dairy products.