Streptomyces anthophorae sp. nov. and Streptomyces nidicola sp. nov., novel actinobacteria isolated from a solitary bee

Six novel actinobacterial strains (BH034^T, BH055, BH097, BH104, BH105 and BH106^T) were isolated from developing brood in nests of the solitary bee species <i>Anthophora bomboides</i> from Bodega Bay, California, USA. Phylogenetic analysis based on a five-gene multilocus sequence alignment and whole-genome data positions all six strains within the genus <i>Streptomyces</i>, with close relation to <i>Streptomyces endophyticus</i> YIM 65594^T and <i>Streptomyces fractus</i> MV32^T. Through genetic and chemotaxonomic analysis, five of the isolates (BH034^T, BH055, BH097, BH104 and BH105) were found to be a clade representing one species [>96% average nucleotide identity (ANI)], whereas BH106^T was a distinct species (<93% ANI with each of the other isolate genomes). Within this species (BH034^T-BH105), the genomes comprised on average 9.6 Mb (±0.4 Mb), encoded 8,640 (±349) predicted genes and had a G+C content of 70.9 (±0.07) mol%. The type strain, BH034^T, contained iso-C_{16 : 0}, anteiso-C_{15 : 0} and iso-C_{15 : 0} as major fatty acids and contained ll-diaminopimelic acid in the cell wall. The remaining strain, BH106^T, represents a distinct species; its genome comprised 9.4 Mb, encoded 8,426 predicted genes and had a G+C content of 70.7 mol%; the major fatty acids were anteiso-C_{15 : 0}, anteiso-C_{17 : 0}, iso-C_{17 : 0} and iso-C_{15 : 0}, and the cell wall also contained ll-diaminopimelic acid. Functional genomic analysis revealed multiple secondary metabolite gene clusters in the bee-associated <i>Streptomyces</i> strains, several of which were found to be absent in closely related <i>Streptomyces</i> species. Based on genotypic, phenotypic and chemotaxonomic analyses, strains BH034-BH105 and BH106 represent two novel species within the genus <i>Streptomyces</i>, for which the names <i>Streptomyces anthophorae</i> sp. nov. (type strain BH034^T=NRRL B-65741^T=DSM 119658^T) and <i>Streptomyces nidicola</i> sp. nov. (type strain BH106^T=NRRL B-65742^T=DSM 119659^T) are proposed.