Melghirimyces algeriensis gen. nov., sp. nov., a member of the family Thermoactinomycetaceae, isolated from a salt lake.

Abstract

A novel filamentous bacterium, designated NariEX(T), was isolated from soil collected from Chott Melghir salt lake, which is located in the south-east of Algeria. The strain was an aerobic, halotolerant, thermotolerant, Gram-positive bacterium that was able to grow in NaCl concentrations up to 21% (w/v), at 37-60 °C and at pH 5.0-9.5. The major fatty acids were iso- and anteiso-C(15:0). The DNA G+C content was 47.3 mol%. The major menaquinone was MK-7, but MK-6 and MK-8 were also present. The polar lipid profile consisted of phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylmonomethylethanolamine (methyl-PE). Results of molecular and phenotypic analysis led to the description of the strain as a new member of the family Thermoactinomycetaceae. The isolate was distinct from members of recognized genera of this family by morphological, biochemical and chemotaxonomic characteristics. Strain NariEX(T) showed 16S rRNA gene sequence similarities of 95.38 and 94.28% with the type strains of Desmospora activa and Kroppenstedtia eburnea, respectively, but differed from both type strains in its sugars, polar lipids and in the presence of methyl-PE. On the basis of physiological and phylogenetic data, strain NariEX(T) represents a novel species of a new genus of the family Thermoactinomycetaceae for which the name Melghirimyces algeriensis gen. nov., sp. nov. is proposed. The type strain of Melghirimyces algeriensis, the type species of the genus, is NariEX(T) (=DSM 45474(T)=CCUG 59620(T)).