欧文氏菌噬菌体的分离纯化及生物学特性研究

Separation and purification of Erwinia carotovora bacteriophages and their biological characteristics

以欧文氏菌胡萝卜亚种为宿主菌,从环境污泥中分离到10株噬菌体。噬菌体热稳定性、pH稳定性分析结果表明噬菌体Erj2、Erb1、Erc2在温度-20～40℃、pH4.0～9.0之间均表现出良好的稳定性。噬菌体生物学特性分析显示,它们的最佳感染复数分别为0.0001、0.001、0.0001;核酸类型均为双链DNA;一步生长曲线表明噬菌体Erj2感染宿主菌的潜伏期为15min,裂解期为13min,裂解量为442;电镜显示,噬菌体Erj2、Erc2的头部均为多面体立体对称结构,Erj2由头部和一长尾构成,Erc2由头部和一短尾构成。共培养实验中,噬菌体Erj2和Erc2分别与宿主菌共培养液OD_(600)均为0.5以下,其中噬菌体Erj2与宿主菌共培养液在4 h后其OD_(600)接近为0,表明该噬菌体能有效的抑制宿主菌的生长,显示具有生防效果和应用前景。

Ten strains of Erwinia carotovora bacteriophages were isolated from the raw sewage. Results of their hot- stability and pH-stability showed that the phages named Erj2, Erbl and Erc2 had relatively high stability within the temperature of -20 - 40℃ and pH value of 4.0 - 9.0. Their biological characteristics analysis showed their optimal multiplicity of infection was 0. 0001, 0. 001, 0. 0001 in turn; They were double-stranded DNA bacteriophage; The growth curve of the page Erj2 showed that the incubation period was 15 rain, the time of burst phase was 13 rain and the burst size was 442; Electron micrographics showed that phage Erj2 and Erc2 exhibited a cubic symmetry, and Erj2 had a long tail, Erc2 had a short tail. Co-culture of phage Erj2 and Erc2 with E. amylovora, resulted in a decrease in the absorbance, whereas the OD600 plots for the Erj2 and Erc2 co-cultures were less than 0.5 ; co-culture with Erj2 resulted in a decrease at OD600 after 4 h nearly to zero. This result showed that the phage could inhibit the growth of host bacteria, indicating a biocontrol effect and application prospects.