Chitinophaga varians sp. nov., isolated from forest soil

A Gram-stain-negative, aerobic, non-motile bacterium, designated strain 10-7W-9003^T, was isolated from the forest soil of Limushan National Forest Park, south-east China (19° 10' 42″ N, 109° 44' 45″ E). Strain 10-7W-9003^T showed a shape change during the course of culture from long filamentous cells (5-10×0.4-0.5 µm) at 5-36 h, to rod shaped (1.0-1.5×0.5-0.7 µm) with inoculation after 2 days. It grew optimally at 28-30 °C and pH 6.5-7.5. On the basis of 16S rRNA gene sequence analysis, it belongs to the genus Chitinophaga and is most closely related to Chitinophaga eiseniae KACC 13774^T and Chitinophaga qingshengii JCM 30026^T, with 16S rRNA gene sequences similarities of 98.8 and 98.3 %, respectively. However, the DNA-DNA hybridization study showed that strain 10-7W-9003^T shared relatively low relatedness values with KACC 13774^T (21.8 %) and JCM 30026^T (20.4 %), respectively. The major fatty acids (>10 %) were iso-C15 : 0, C16 : 1ω5c and iso-C17 : 0 3-OH. The genomic DNA G+C content was 50.7 mol%. It contained MK-7 as the major quinone. The phenotypic, chemotaxonomic and phylogenetic data clearly showed that strain 10-7W-9003^T represents a novel species of the genus Chitinophaga, for which the name Chitinophaga varians sp. nov. is proposed. The type strain is 10-7W-9003^T (=GDMCC 1.1252^T=KACC 19415^T=KCTC 52926^T).