Streptomyces humicola sp. nov., a novel actinobacterium isolated from peat swamp forest soil in Thailand

A polyphasic approach was used to describe strain RB6PN25T, an actinobacterium isolated from peat swamp forest soil in Rayong Province, Thailand. The strain was a Gram- stain-positive and filamentous bacterium that contained iota iota-diaminopimelic acid, mannose and ribose in whole -cell hydrolysates. MK -9(H8) was the major menaquinone. The major fatty acids were iso- C16:0, anteiso-C15: 0 and iso-C15:0.The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphati-dylinositol, two unidentified glycophospholipids, two unidentified aminolipids and an unidentified phospholipid. The 16S rRNA gene sequences analysis indicated that it was most closely related to Streptomyces rubrisoli DSM 42083T (97.6 %) and Strepto-myces palmae TBRC 1999T (97.4 %). Strain RB6PN25T exhibited low average nucleotide identity and digital DNA-DNA hybridi-zation values with S. rubrisoli DSM 42083T (78.6 %, 23.2 %) and S. palmae TBRC 1999T (76.0 %, 22.6 %). The DNA G+C content of strain RB6PN25T was 69.9%. The results of phenotypic, chemotaxonomic, genotypic and phylogenetic analyses reveal that strain RB6PN25T represents a novel species of the genus Streptomyces, for which the name Streptomyces humicola sp. nov. is proposed. The type strain is RB6PN25T (=TBRC 14819T=NBRC 115204T).

Automated summary

A polyphasic approach was used to describe strain RB6PN25T, a newly identified actinobacterium isolated from peat swamp forest soil. It was named Streptomyces humicola sp. nov. based on its distinct characteristics observed through phenotypic, chemotaxonomic, genotypic, and phylogenetic analyses.