Alsobacter soli sp. nov., a novel bacterium isolated from paddy soil, emended description of the genus Alsobacter and description of the family Alsobacteraceae fam. nov.

Strain SH9, an aerobic bacterium isolated from a paddy soil sample collected in Shanghai, China, was characterized using a polyphasic approach. It grew optimally at pH 7.0, temperatures of 30-35 °C and in the presence of 1 % (w/v) NaCl. Comparative analysis of 16S rRNA gene sequences showed that strain SH9 fell within the genus Alsobacter, forming a clear cluster with the type strain of Alsobacter metallidurans, with which it exhibited a 16S rRNA gene sequence similarity value of 98.5 %. Cells of strain SH9 were Gram-stain-negative, motile, non-spore-forming, rod-shaped, positive for catalase and oxidase activity, and negative for atmospheric nitrogen fixation and nitrate reduction. The strain was a chemo-organotrophic bacterium, incapable of growth on C1 substrates. The chemotaxonomic properties of strain SH9 were consistent with those of the genus Alsobacter: the predominant ubiquinone was Q-10, and the major fatty acid was summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c). The major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylcholine and phosphatidylmonomethylethanolamine. The DNA G+C content was 68.5 mol%. Strain SH9 exhibited a DNA-DNA relatedness level of 20±2 % with A. metallidurans NBRC 107718. Based on the data obtained, strain SH9 represents a novel species of the genus Alsobacter, for which the name Alsobactersoli sp. nov. is proposed. The type strain is SH9 (=JCM 32501=CCTCC AB 2017284). A new family, Alsobacteraceae fam. nov., is also proposed encompassing strain SH9 and Alsobacter metallidurans NBRC 107718.