粪肠球菌抗噬菌体菌株的筛选

Selection of Phage Resistant Strains of Enterococcus faecalis

本实验通过次级感染，诱使粪肠球菌EF-31自发突变的方法筛选25株耐噬菌体的抗性菌株。通过对25株噬菌体耐性菌株的传代稳定性、噬菌体抗性、测定，最终获得3株具有稳定的噬菌体抗性及良好的发酵性能的噬菌体抗性菌株，分别是EF-31-17、EF-31—7、EF-31—14。这3株抗性菌株连续传代10次，仍能在感染噬菌体的培养基中正常生长；噬菌体抗性EOP值均〈1．0×10^-8：生长特性、产酸性能亦优于原始菌株。发酵生产受噬菌体污染时提供了后备替换菌种资源。

Enterococcus faecalis EF-31 were used as original strain, the bacteriophage-resistant mutants were isolated by secondary culture of 25 strains. By 25 bacteriphage-resistant characteristics related to their phage-resistance capacities, phage-resistance stability, finally obtained a stable phage resistance and good fermentation performance 3 bacteriphage-resistant, respectively, EF-31-17, EF-31-7, EF-31-14. The three strains of resistant strains were passaged 10 times continuously, and they could grow normally in the culture medium of the infected phage. The phage resistance EOP values were less than 〈 1.0×10^-8 The growth characteristics and acid-producing properties were also better than those of the original strains.