Streptomyces fractus sp. nov., a novel streptomycete isolated from the gut of a South African termite.

Abstract

An actinobacterial strain, MV32(T), was isolated from the paunch region of the hindgut of a South African termite, Amitermes hastatus, as part of an investigation of the actinobacterial population residing within this higher order termite species. Strain MV32(T) was chosen for further study from amongst the many potentially novel actinomycete isolates because of its strong antibacterial activity against Mycobacterium aurum A+. 16S rRNA gene phylogenetic analyses clearly placed strain MV32(T) within the genus Streptomyces, with 99.3% sequence similarity to its closest relative, Streptomyces endophyticus YIM 65594(T). Despite this high sequence similarity, DNA-DNA hybridisation analysis showed a DNA relatedness value of 62 ± 2%, to S. endophyticus DSM 41984(T) (indicating that strain MV32(T) belongs to a different genomic species), as well as values of 14.4 ± 0.8 and 10.4 ± 2.9%, respectively, to its next closest relatives, Streptomyces kunmingensis NRRL B-16240(T) and Streptomyces cinnabarinus NRRL B-12382(T). Based on these results and supported by both chemotaxonomic data and a number of phenotypic differences, strain MV32(T) is proposed to represent a new species within the genus Streptomyces, with the name Streptomyces fractus (= DSM 42163(T) = NRRL B-59159(T)).