Nonomuraea thermotolerans sp. nov., a thermotolerant actinomycete isolated from mushroom compost

A novel thermotolerant actinomycete, designated strain 3-33-9B T , was isolated from mushroom compost in Nanning, Guangxi province, China. The strain grew at 25-60 °C, pH 7.0-11.0 and with 0-2.0 % (w/v) NaCl. Strain 3-33-9B T formed extensively branched aerial mycelia and substrate mycelia. Spiral spore chains with one to three turns were composed of about 3-15 non-motile spores with a wrinkled surface. The organism contained meso -diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan. Whole-cell hydrolysates contained madurose, galactose, glucose and ribose. The cellular fatty acid profile mainly consisted of iso-C 16 : 0 and C 17 : 0 . The quinone system was predominantly composed of MK-9(H 4 ). The DNA G+C content of strain 3-33-9B T was 72.5 mol%. The organism showed a combination of morphological and chemotaxonomic properties typical of members of the genus Nonomuraea . Moreover, 16S rRNA gene sequence analysis also showed that the organism belonged to the genus Nonomuraea ; in the 16S rRNA gene tree of the genus Nonomuraea , strain 3-33-9B T formed a distinct phyletic line and was most closely related to Nonomuraea fastidiosa NBRC 14680 T (97.3 % 16S rRNA gene sequence similarity). However, phenotypic characteristics of strain 3-33-9B T were significantly different from N. fastidiosa NBRC 14680 T , and DNA-DNA hybridization showed little relatedness (31.6-35.2 %) between the two strains. Based on the phenotypic and phylogenetic data, strain 3-33-9B T represents a novel species of the genus Nonomuraea , for which the name Nonomuraea thermotolerans sp. nov. is proposed. The type strain is 3-33-9B T ( = ATCC BAA-2629 T  = CGMCC 4.7161 T ).