Leadbetterella byssophila gen. nov., sp. nov., isolated from cotton-waste composts for the cultivation of oyster mushroom.

A bacterial strain, designated 4M15T, was isolated from cotton-waste composts used as mushroom cultivation in South Korea. Properties of this isolate were studied on the basis of physiological and biochemical characteristics, fatty acid profile, isoprenoid quinone, DNA G+C content and phylogenetic position based on 16S rRNA gene sequence analysis. The strain was found to form a distinct phylogenetic lineage related to the family 'Flexibacteraceae' within the phylum 'Bacteroidetes'. No recognized species showed >85 % 16S rRNA gene sequence similarity to strain 4M15T. The fatty acid profile of strain 4M15(T) included C(16 : 1)omega7c/iso-C(15 : 0) 2-OH (30.5 %), iso-C(15 : 0) (24.2 %), iso-C(15 : 0) 2-OH/C(16 : 1)omega7c (15.9), iso-C(17 : 0) 3-OH (10.5 %) and C(16 : 0) (5.6 %). The major isoprenoid quinone was menaquinone MK-7. The DNA G+C content was 33.0 mol%. Cells were Gram-negative, strictly aerobic, rod-shaped, non-motile, catalase-positive, oxidase-positive and flexirubin-positive. The strain hydrolysed aesculin, gelatin, starch and tyrosine. Several phenotypic tests could be used to differentiate strain 4M15T from other members of the family 'Flexibacteraceae'. On the basis of the data presented, strain 4M15T should be assigned to the phylum 'Bacteroidetes' as a novel genus and species, for which the name Leadbetterella byssophila gen. nov., sp. nov. is proposed. The type strain is 4M15T (=KACC 11308T=DSM 17132T).