污水处理系统中鼠伤寒沙门菌噬菌体的分离及其生物学特性的研究

Identification and biological property study of a Salmonella typhimurium phage isolated from A^2O wastewater treatment system

目的从污水处理系统中筛选强裂解能力的鼠伤寒沙门菌噬菌体,研究其生物学特性,为污水处理中病原菌的去除提供更好选择。方法采用双层平板法分离污水中的鼠伤寒沙门菌噬菌体,纯化后测定其生物学特性。结果筛出的鼠伤寒沙门菌噬菌体Pst87170,其头部为正二十面体立体对称结构,直径约87 nm,尾部较长约为170 nm,直径约9 nm,属于ds DNA长尾噬菌体科;最佳感染复数为0.1,潜伏期约100 min,爆发期约130 min,裂解量约103 PFU/cell。噬菌体Pst87170具有较强的裂解能力及良好的热稳定性和酸碱耐受性。结论噬菌体Pst87170具有研制成为噬菌体混合制剂而应用于污水处理系统中去除相应病原菌的潜力。

Objective To isolate a phage with a high lytic activity on Salmonella typhimurium from an A^2O wastewater treatment system and to study its biological property and provide a better choice for removing pathogenic bacteria in wastewater treatment system. Methods Salmonella typhimurium phage was isolated and purified by two layer plating method and its biological property was determined. Results The phage belonging to Siphoviridae had a regular icosohedron cubic symmetry head with 87 nm in diameter and a long tail（about 170 nm in length and about 9 nm in width）. The optimal MOI（multiplicity of infection）was 0.1. One-step growth kinetics of the phage Pst87170 showed that the latent period and the burst period were about 100 and 130 min,respectively,and the average burst size was about 103 phage particles per infected cell. The phage showed superior thermal stability and tolerance of p H. Conclusion Phage Pst87170 has the potential to be developed into phage mixtures applying to removal of corresponding pathogens in wastewater treatment system.