瑞士乳杆菌M14-1所产细菌素的分离纯化及抑菌特性分析

Isolation,Purification and Characterization of Bacteriocin M14-1,a Bacteriocin Produced by Lactobacillus helveticus

瑞士乳杆菌M14-1发酵上清液经硫酸盐沉淀后得到粗蛋白提取物,再经离子交换、C18固相萃取进行进一步纯化后得到高纯度的纯化产物。研究细菌素M14-1酶敏感性、酸碱稳定性、热稳定性、抑菌谱以及细菌素产量与菌株生长关系。研究发现细菌素M14-1对蛋白酶K、胰蛋白酶、胃蛋白酶敏感,对过氧化氢酶不敏感。该细菌素热稳定性较差,121℃处理15 min后,活性下降。细菌素M14-1在pH2.0~10.0内具有抑菌活性。抑菌谱结果表明细菌素M14-1抑菌谱较窄,仅对单增李斯特氏菌有较好的抑制效果。瑞士乳杆菌M14-1在发酵16h后达到稳定期,而细菌素M14-1最佳收获时间为瑞士乳杆菌M14-1发酵12 h后。

The fermentation supernatant of bacteriocin M14-1 was purified by sulfate precipitation and crude protein extract was obtained.High-purity product was purified by cation exchange and solid phase extraction.The bacteriocin enzyme sensitivity,pH stability,thermal stability,antimicrobial spectrum,bacteriocin production and growth of the strain were studied.Bacteriocin M14-1 was sensitive to protease K,trypsin and pepsin,but insensitive to catalase.As result of bacteriocin M14-1 poor thermal stability,inhibition activity was decreased after 121℃for 15 min.The bacteriocin had good antibacterial activity in pH2.0-10.0.The antimicrobial spectrum showed that bacteriocin of L.helvetic us M14-1 only inhibited the growth of L.monocytogenes.L.helvetic us M14-1 reached stable stage for 16 h of fermentation.The optimal harvest time for bacteriocin was 12 h.