Microbispora cellulosiformans sp. nov., a novel actinomycete with cellulase activity isolated from soil in the cold region

A novel cellulase-producing actinomycete strain Gxj-6 T , isolated from soil in the cold region (Heihe city, Heilongjiang province, the northernmost part of China), subjected to a taxonomic study using a polyphasic approach. In the neighbour-joining phylogenetic tree based on 16S rRNA gene sequences, strain Gxj-6 T fell within the clade comprising the type strains of species of the genus Microbispora . 16S rRNA gene sequence similarity studies exhibited that species Gxj-6 T was most closely related to Microbispora bryophytorum NEAU-TX2-2 T (99.45%), Microbispora fusca NEAU-HEGS1-5 T (99.41%), Microbispora camponoti 2C-HV3 T (99.31%) and Microbispora rosea subsp. rosea JCM 3006 T (98.68%). Organism Gxj-6 T contained MK-9(H 2 ) as the predominant ubiquinone and C 18:0 10-methyl as the major fatty acid. The major polar lipids of culture Gxj-6 T were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol mannoside, three unidentified phospholipids, two unidentified glycolipids and two unidentified lipids. The DNA G+C content of strain Gxj-6 T was 71.25 mol%. The morphological and chemotaxonomic properties of the strain are also consistent with those members of the genus Microbispora . Combinated with the lower DNA–DNA relatedness values, phenotypic properties, physiology and biochemistry distinctiveness with other recognized species strains, revealed that strain Gxj-6 T is separated from other phylogenetically closely species of the genus Microbispora . Therefore, strain Gxj-6 T is considered to represent a novel species of the genus Microbispora , for which the name Microbispora cellulosiformans sp. nov. is proposed. The type strain is Gxj-6 T (= CGMCC 4.7605 T = DSM 109712 T ).