Streptomyces euryhalinus sp. nov., a new actinomycete isolated from a mangrove forest

A Gram-positive, aerobic, non-motile actinomycete (strain MS 3/20T) was isolated from the sediment of the Sundarbans mangrove forest in India. On International Streptomyces Project (ISP) medium 2, the isolate produced yellowish brown to red aerial hyphae that carried spiny-surfaced spores in a retinaculum-apertum arrangement. Whole-cell hydrolysate of the strain contained LL-diaminopimelic acid and galactose. Predominant menaquinones were MK-9(H8) and MK-9(H6). Diagnostic polar lipids were glycolipid, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, unidentified phospholipid and unidentified amino lipid. The major fatty acids were anteiso-C15:0 (17.53%), iso-C16:0 (23.89%) and anteiso-C17:0 (10.29%). The strain showed 100% 16S ribosomal RNA (rRNA) gene sequence similarity with Streptomyces variabilis NBRC 12825T, Streptomyces erythrogriseus LMG 19406T, Streptomyces griseoincarnatus LMG 19316T and Streptomyces labedae NBRC 15864T. However, strain MS 3/20T could be distinguished from these and seven other closely related species based on low levels of DNA–DNA relatedness (27.2–53.8%), supported by the unique banding pattern obtained from random amplified polymorphic DNA-PCR amplification and the distinctive matrix-assisted laser desorption/ionization–time-of-flight/mass spectrometry (MALDI-TOF/MS) profile of whole-cell proteins acquired for strain MS 3/20T in comparison with its phylogenetic relatives. Disparate morphological, physiological and chemotaxonomic features, principally growth in NaCl, further corroborated the distinction of strain MS 3/20T from other phylogenetic relatives. Strain MS 3/20T is therefore suggested to be a novel species of the genus Streptomyces, for which the name Streptomyces euryhalinus sp. nov. is proposed. The type strain is MS 3/20T (=CICC 11032T=DSM 103378T).