小单孢菌40027菌株噬菌体的分离及其生物学特性的研究

Studies on the isolation and biological characterization of actinophages infecting Micromonospora sp. 40027

摘要:

以福堤霉素A产生菌──小单孢菌40027菌株为指示菌,从土壤中分离得到三株噬菌体:ΦHAU7、ΦHAU9和ΦHAU11。三株噬菌体的寄主专一性较强,在测试的15株放线菌菌株中,三株噬菌体能感染小单孢菌40027菌株和A-M-01菌株,ΦHAU9和ΦHAU11还能感染蔷薇小单孢菌(Micromonospora purprea)。三株噬菌体都是由多面体的头部和尾部组成;形成噬菌斑时培养基中适宜的Ca²⁺、Mg²⁺浓度分别为32mM和30mM;ΦHAU7在储存液中适宜的pH范围为6~12,而其它两株噬菌体的适宜的pH范围为6~10;在储存过程中三株噬菌体适宜的温度范围为28~37℃,经60℃保温30min后,除ΦHAU7仍有53%活力之外,其它两株噬菌体全部失活。限制性内切酶酶切结果表明:三株噬菌体基因组DNA均为双链DNA;基因组大小分别约为60kb、58kb和55kb。高压脉冲电泳结果揭示:三株噬菌体基因组DNA均具有粘性末端。

Abstract:

Three actinophages, ΦHAU7、ΦHAU9 and ΦHAU11, were isolated from soil using Micromonospora sp. 40027 as a indicator strain. Three phages showed very narrow host-ranges. Three phages could infect both Micromonospora sp. 40027 and Micromonospora A-M-01, ΦHAU9 and ΦHAU11 could also form plaques on Micromonospora purprea. All of the three phage particles have the hexagonal heads and tails; the plaque formation of three phages on Micromonospora sp. 40027 were best on DNA medium with addition of 32mM Ca²⁺ and 30mM Mg²⁺; ΦHAU7 was stable at pH 6～12, and other phages were stable at pH 6～10; the suitable incubation temperature for the propagation of three phages was between 28℃～37℃; 53% of ΦHAU7 remained viable and none of other phages was alive when they were incubated at 60℃ for 30min. Restriction digestion analysis of genomes of three phages indicated that they were all double-stranded DNA with cohesive ends, their genome size are ca. 60 kb、58 kb and 55kb, respectively.