【摘要】 用NaCl饱和的乳酸乳酸球菌(Lactococcus lactis subsp. lactis)AL2发酵液经正丙醇提取和CM-Sephadex C-25柱层析,得到聚丙烯酰胺凝胶电泳纯的乳链菌肽组分,比活力从24427IU/mg提高到39865IU/mg,活力回收为41.7％。α—胰凝乳蛋白酶可使乳链菌肽丧失活性;在低pH条件下,乳链菌肽对热较稳定;对许多革兰氏阳性菌有强烈抑制作用,而对革兰氏阴性菌、酵母菌和霉菌没有作用。更多还原

【Abstract】 Nisin from Lactococcus lactis subsp. lactis AL2 was extracted with n-propanol from NaCl-saturated culture and purified by ion-exchange chromotography on CM-Sephadex C-25. Nisin was purified 1.63 fold with a yield of 41.7%. The molecular weight of nisin was determined by SDS-PAGE to be about 3500. Nisin activity was stable at low pH and sensitive to digestion by a-chymotrypsin. Nisin is capable of inhibiting a broad range of gram-positive bacteria. In contrast, the gram-negative bacteria, yeasts, molds and Nip+ L. lactis subsp. lactis ATCC11454 were not inhibited.更多还原