Streptomyces beihaiensis sp. nov., a chitin-degrading actinobacterium, isolated from shrimp pond soil. Issue 4 (21st April 2023) - Xie, Junjie
Abstract : A Gram-stain-positive actinobacterium, designated strain GXMU-J5 T, was isolated from a sample of shrimp pond soil collected in Tieshangang Saltern, Beihai, PR China. The morphological, chemotaxonomic and phylogenetic characteristics were consistent with its classification in the genus Streptomyces . The organism formed an extensively branched substrate mycelium, with abundant aerial hyphae that differentiated into spores. Phylogenetic analysis of 16S rRNA gene sequences showed that strain GXMU-J5 T was most related to Streptomyces kunmingensis DSM 41681 T (similarity 97.74 %) and Streptomyces endophyticus YIM 65594 T (similarity 96.80 %). However, the values of digital DNA–DNA hybridization, average nucleotide identity and evolutionary distance of multilocus sequence analysis between strain GXMU-J5 T and its closest relatives indicated that it represented a distinct species. Strain GXMU-J5 T contained ll -diaminopimelic acid and the major whole-cell hydrolysates were xylose and galactose. The predominant menaquinones of strain GXMU-J5 T were revealed as MK-9(H4), MK-9(H6) and MK-9(H8). The polar lipids consisted of diphosphatidylglycerol, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylinositol mannosides and phospholipids of unknown structure containing glucosamine. The predominant cellular fatty acids were iso-C15 : 0, anteiso-C15 : 0, iso-C16 : 0, iso-C17 : 0 and anteiso-C17 : 0 . The whole genome size of strain GXMU-J5 T was 6.79 Mbp with a 71.39 mol% G+C content. Genomic analysis indicated that strain GXMU-J5 T had the potential to degrade chitin. On the basis of these genotypic and phenotypic data, it is supported that strain GXMU-J5 T represents a novel species of the genus Streptomyces, for which the name Streptomyces beihaiensis sp. nov. is proposed. The type strain is strain GXMU-J5 T (=MCCC 1K08064 T =JCM 35629 T ).