Streptomyces polyantibioticus sp. nov., isolated from the banks of a river

As part of an antibiotic-screening programme, an actinomycete, designated strain SPR(T), was isolated from soil collected from the banks of the Umgeni River, KwaZulu-Natal Province, South Africa. The isolate produced branching vegetative mycelia with sporangiophores bearing sporangia developing at a late stage of growth. The sporangia contained smooth, almond-shaped, non-motile spores. Strain SPR(T) exhibited antibiosis against various Gram-positive and Gram-negative bacteria, including Enterococcus faecium VanA (a vancomycin-resistant strain), Mycobacterium aurum A+ and Escherichia coli ATCC 25922. The chemotaxonomic characteristics of the strain, with the exception of the phospholipid pattern, corresponded with those of the members of the family Streptomycetaceae Waksman and Henrici 1943. Furthermore, phylogenetic analysis based on 16S rRNA genes showed that the strain was closely related to members of the genus Streptomyces, which supports its classification in the family Streptomycetaceae. Thus strain SPR(T) represents a novel species of the genus Streptomyces, for which the name Streptomyces polyantibioticus sp. nov. is proposed. The type strain is SPR(T) (=DSM 44925(T)=NRRL B-24448(T)).