Preliminary Characterization of a Group of Actinophages of the Thermophilic Actinomycete Genus <i>Saccharomonospora</i>

Abstract

The comparison of the Saccharomonospora phages φSaC1, φSaG1, φSaV1, φSaV2, φSaV3, and Tml demonstrated that they all belong to a single group of closely related actinophages: they were similar with regard to host range, virion mophology (Bl type), genome length (43–45 kb), and GC content of their genomes (63, 3% G + C). Furthermore, DNA-DNA hybridization showed that the phage genomes had a high degree of homology to each other. The phages are, therefore, proposed as representatives of a new bacteriophage species in the sense of the ICTV.

Thermocrispum gen. nov., a New Genus of the Order Actinomycetales, and Description of Thermocrispum municipale sp. nov. and Thermocrispum agreste sp. nov.

“…Furthermore, the latter nine isolates formed three subgroups, as follows: (i) three of these strains were lysed by all five hages isolated for strains MKD8, MKD10, MKD19, MKD35 , and MKD38; (ii) two strains (TMS14 and MKD38) were not lysed by $10 even if high phage titers were used, and one strain (MKD35T) was lysed by this phage only if a high phage titer was used; and (iii) three strains (MKD10, MKD19, and MKD57) were sensitive to phages $35 and $38 only if high phage titers were used. These results also revealed the following problems that arise in phage typing studies: (i) more or less strong restriction barriers by some strains within a genus, as described previously for Succharopolysporu hirsutu and Sacchuropolyspora elythrueu (55,56) and some strains of Streptornyces coeZicoZor Miiller (53) and also found for MKD19 and CHB77T; (ii) occurrence of lysogeny in some strains and repression of homoimmune phages (55); and (iii) temperate phages that have the ability to lysogenize their hosts (22,54,56) (this property was also observed with phage $10, which lysogenized four of the isolates, MKD19, MKD35T, MKD57, and TMD78).…”

Corynephage Cog, a Virulent Bacteriophage of Corynebacterium Glutamicum, and its Relationship to GA1, an Inducible Phage Particle from Brevibacterium Flavum

“…Hybridizations were carried out in 6 x SSC (1 x SSC is 0.15 M-NaCI, 0.015 ~l-trisodium citrate, pH 7.0) at 60 °C; washing conditions for the determination of hybridization stringency (Meinkoth & Wahl, 1984) were 0.2 x SSC, 60 °C for mediumstringency (homology > 80~) and 0.05 x SSC, 60 °C for high stringency (homology >90~). The base composition of the phage DNA was determined according to Schneider et al (1989). ~GA1 DNA was prepared after u.v.…”