Proposal of Mycetocola gen. nov. in the family Microbacteriaceae and three new species, Mycetocola saprophilus sp. nov., Mycetocola tolaasinivorans sp. nov. and Mycetocola lacteus sp. nov., isolated from cultivated mushroom, Pleurotus ostreatus.

The taxonomic positions of 10 tolaasin-detoxifying bacteria, which were isolated from the cultivated mushroom Pleurotus ostreatus, were investigated. These strains are Gram-positive, obligately aerobic, non-sporulating and irregular rod-shaped bacteria. They have the following characteristics: the major menaquinone is MK-10, the DNA G+C content ranges from 64 to 65 mol%, the diamino acid in the cell wall is lysine and the muramic acid in the peptidoglycan is an acetyl type. The major fatty acids are anteiso-C15:0 and anteiso-C17:0. On the basis of morphological, physiological and chemotaxonomic characteristics, together with DNA-DNA reassociation values and 16S rRNA gene sequence comparison data, the new genus Mycetocola gen. nov. is proposed for these bacteria in the family Microbacteriaceae and three new species are also proposed: Mycetocola saprophilus sp. nov. (type strain CM-01T = IFO 16274T = MAFF 211324T = NRRL B-24119T), Mycetocola tolaasinivorans sp. nov. (type strain CM-05T = IFO 16277T = MAFF 211325T = NRRL B-24120T) and Mycetocola lacteus sp. nov. (type strain CM-10T = IFO 16278T = MAFF 211326T = NRRL B-24121T). The type species of the genus is Mycetocola saprophilus sp. nov.