Tenggerimyces mesophilus gen. nov., sp. nov., a member of the family Nocardioidaceae

Abstract

A novel aerobic actinomycete, designated strain I12A-02601T, was isolated from a desert soil crusts sample collected from the Shapotou region of Tengger Desert, north-west China. The substrate mycelia of this isolate were well-developed and branched, but not fragmented. The maturity aerial mycelia formed short chains of small, rod-shaped spores. The strain contained ll-diaminopimelic acid, dd-diaminopimelic acid, galactose, glucose, ribose and xylose in its whole-cell hydrolysates. The polar lipids consisted of diphosphatidylglycerol, N-acetylglucosamine-containing phospholipids, phosphatidylinositolmannoside and glycolipids. The predominant menaquinones were MK-10(H6) and MK-10(H8). The major fatty acids were iso-C15 : 0, anteiso-C15 : 0, C16 : 0, anteiso-C17 : 0 and iso-C16 : 0. The G+C content of the genomic DNA was 72.2 mol%. The 16S rRNA gene sequences comparison showed that strain I12A-02601T was most closely related to members of the family Nocardioidaceae, such as Actinopolymorpha alba YIM 48868T (93.3 % sequence similarity), Actinopolymorpha pittospori PIP 143T (93.2 %), and Flindersiella endophytica EUM 378T (93.2 %). In the phylogenetic tree based on 16S rRNA gene sequences, strain I12A-02601T formed a clade with the members of the genera Flindersiella, Thermasporomyces, and Actinopolymorpha in the family Nocardioidaceae. Combined data from this taxonomic study using a polyphasic approach, led to the conclusion that strain I12A-02601T represents a novel species of a new genus in the family Nocardioidaceae, for which the name Tenggerimyces mesophilus gen. nov., sp. nov. is proposed. The type strain of the type species is I12A-02601T ( = CPCC 203544T = DSM 45829T = NBRC 109454T).