戊糖乳杆菌31-1菌株所产细菌素的理化及生物学特性

Characterization of Bacteriocin produced by Lactobacillus pentosus 31-1

研究了本组纯化的戊糖乳杆菌31～1菌株所产细菌素的理化和生物学特性及其对敏感菌株的抑菌作用，发现该细菌素在80℃热处理15min后活性基本不变，121℃处理15min仍保持一定活性；在pH2～8范围内37℃处理4h保持稳定。当pHi9时活性逐渐降低。胃蛋白酶、胰蛋白酶、蛋白酶K、木瓜蛋白酶、中性蛋白酶均可使该细菌素完全失活；α-淀粉酶可使其部分失活；酸性蛋白酶、溶菌酶不能使其失活。该细菌素抑菌效果明显，在3～5h内可减少敏感菌细胞数10^2～10^3个。测定了其抑菌谱，该细菌素可抑制乳杆菌属、链球菌属、片球菌属中的大部分菌株，还可抑制金黄色葡萄球菌、大肠杆菌、芽抱杆菌中的部分菌株。该细菌素是一种具有良好热、酸稳定性的蛋白活性物质，用于食品防腐将具有较高的安全性。

This study reports the characterization, spectrum of bacteriocin produced by Lactobacillus pentosus 31-1. This bacteriocin remained active when heated at 80℃ for 15 rain, and partly active at 121 ＂C for 15 rain. It was also active after incubation in pH 2 - 8 environment for 4 h at 37℃, but only partially inactive media above pH 9. Treatment with pepsin, proteinase K, trypsin, papain, neutral proteinase fully inactivated the bacteriocin, but was part-inactivated by a-amylase. The mechanism of activity of bacteriocin is bactericidal, as shown by an obvious decrease of about 2- 3 orders of magnitude in the viable cell numbers of L. plantarum over a period of 3 - 5 h. The bacteriocin had a broad spectrum, including most strains from Lactobacillus, Streptococcus, Pediococcus, especially including Staphylococcus aureus, E. coil, Bacillus cereus, B. subtilis and B. megaterium. Bacteriocin produced by Lactobacillus pentosus 31-1 was an active protein with stability to heat and acid, which will have good potential application in food preservation.