Streptomyces alkaliphilus

Abstract: A novel strain, designated No. 7 T , was isolated from a sediment sample collected from the alkaline, saline Lake Elmenteita located in the Kenyan Rift Valley. The optimal growth for the strain was found to be at temperature 30-35 C, at pH 8.0-12.0 in the presence of 7.0-10.0 % (w/v) NaCl. The strain was observed to form a light green beige abundant aerial mycelium on Horikoshi 1 agar and to have morpho- logical and chemotaxonomic characteristics typical of members of the genus Streptomyces. The peptidogly- can was found to contain LL-diaminopimelic acid as the diamino acid, with no diagnostic sugars identified. The predominant menaquinone was identified as MK-9(H6). The main polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and an unknown phospholipid. Cellular fatty acids were found to consist of saturated branched-chain acids with iso-C15:0, anteiso-C15:0, iso-C16:0 and anteiso-C17:0 acids predominating. The type strain had a genomic DNA G?C content of 72.8 mol% and formed a distinct phyletic line within the genus Streptomyces. Based on the chemo- taxonomic results, 16S rRNA gene sequence analysis and the low DNA-DNA hybridization value with the type strain of Streptomyces calidiresistens ,i t is proposed that strain No. 7 T (= DSM 42118 = CECT 8549) represents a novel species, Streptomyces alka- liphilus. The INSDC accession number for the 16S rRNA gene sequence of strain No. 7 T is KF976730.