对分离自四川传统肉制品的戊糖乳杆菌C50-6产生的戊糖乳杆菌素进行了纯化,研究其理化性质和生物学活性,结果表明:发酵液经(NH4)2SO4盐析和Toyopearl SP-650M阳离子交换层析纯化后,细菌素的回收率为21.76%,纯化倍数为39.15倍;经Tricine-SDS-PAGE和电泳条带抑菌试验测得该乳杆菌素分子质量约2 500u;该细菌素对酸和热稳定,对木瓜蛋白酶、胰蛋白酶和蛋白酶K敏感;对供试的革兰氏阳性菌、革兰氏阴性菌和少数真菌具有较强抑制作用,对多数乳酸菌无抑制作用。

Lactobacillus pentosus C50-6,isolated from traditional Sichuan fermented meat products,produces a bacteriocin,pentocin C50-6.The bacteriocin was purified by ammonium sulphate precipitation and Toyopearl SP-650M cation-exchange column.The purification resulted in a yield of 21.76% of the original activity and a 39.15-fold increase in specific activity.The estimated molecular weight of pentocin C50-6 was approximately 2.5 ku based on Tricine-SDS-PAGE,in which bacteriocin activity was confirmed by overlayer techniques were in accordance with this value.The bacteriocin was heat resistant(121°C for 20 min),active at pH values between 2.0~6.0 and inactivated by papain,trypsin and proteinase K.The bacteriocin demonstrated inhibitory activity towards some species of Gram-positive,Gram-negative bacteria and minority of fungus tested,but was not active against majority of lactic acid bacteria.These results indicate that pentocin C50-6 may have potential for use as food preservative.