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

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.