Haloactinopolyspora alba gen. nov., sp. nov., a halophilic filamentous actinomycete isolated from a salt lake, with proposal of Jiangellaceae fam. nov. and Jiangellineae subord. nov.

Abstract

A halophilic, filamentous actinomycete strain, designated YIM 93246T, was isolated from a salt lake in Xinjiang province, north-west China, and subjected to polyphasic taxonomic characterization. The isolate grew in the presence of 7–23 % (w/v) NaCl, but not in the absence of NaCl. Strain YIM 93246T had particular morphological properties, forming aerial mycelium that had long spore chains and pseudosporangium-like, rhiziform spore aggregates at maturity. ll-DAP was the cell-wall diamino acid and glucosamine, mannose, glucose, arabinose and galactose were the cell-wall sugars. The major fatty acids were iso-C16 : 0, anteiso-C15 : 0 and anteiso-C17 : 0. MK-9 (H4) was the predominant menaquinone and the genomic DNA G+C content was 70.5 mol%. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain YIM 93246T clustered with the genus Jiangella. The sequence similarities between strain YIM 93246T and Jiangella alba, Jiangella gansuensis and Jiangella alkaliphila were 96.9, 96.9 and 96.6 %, respectively. Based on morphological, physiological and chemotaxonomic differences, and phylogenetic analysis, a novel genus and species, Haloactinopolyspora alba gen. nov., sp. nov., is proposed. The type strain of the species is YIM 93246T (=DSM 45211T=KCTC 19409T). Additionally, phylogenetic analysis placed the genus Jiangella together with strain YIM 93246T within the order Actinomycetales as an independent lineage, clearly distinguished from other described suborders of the class Actinobacteria. Hence, based on phylogenetic characteristics, the genus Jiangella together with the newly proposed genus Haloactinopolyspora are proposed to be classified as Jiangellaceae fam. nov. and Jiangellineae subord. nov.