嗜酸乳杆菌产细菌素的分离纯化研究

SEPARATION AND PURIFICATION OF BACTERIOCINS PRODUCED BY LACTOBACILLUS ACIDOPHILUS

对一株嗜酸乳杆菌所产细菌素进行了分离纯化,并研究了其生物学特性.结果表明,嗜酸乳杆菌产的细菌素具有热稳定性,在120℃处理30 min仍保留活性,该细菌素在pH2.09.0范围内有较好的稳定性.发酵上清液对蛋白酶敏感,表明此抑菌物质为蛋白类物质,对革兰氏阴性菌及革兰氏阳性菌均有抑制作用.发酵上清液经过硫酸铵沉淀、透析后得到细菌素粗提液,然后利用SephadexG-50凝胶层析进行纯化,采用Tricine-SDS-PAGE电泳测其相对分子质量约为2 000.

We carried out the separation and purification of bacteriocins produced by Lactobacillus acidophlus and studied the biological characteristics.The results showed that the bacteriocins produced by Lactobacillus acidophlus had thermal stability and better stability in the pH range of 2.0 to 9.0,and still kept the activity after being processed at 120 ℃ for 30 min.The fermented supernant was sensitive to proteases,which showed that the antibacterial substance belonged to proteins;and the fermented supernant had inhibitory effects on Gram-positive bacteria and Gram-negative bacteria.We could prepare the crude bacteriocin extract after ammonium sulfate precipitation and dialysis of the fermented supernant,then purified the crude bacteriocin extract by SephadexG-50 gel chromatography,and determined that the molecular weight of the bacteriocins was about 2 000 by Tricine-SDS-PAGE.