Aliibacillus thermotolerans gen. nov., sp. nov.: a thermophilic and heterotrophic ammonia-oxidizing bacterium from compost.

A novel moderately thermophilic and heterotrophic ammonia-oxidizing bacterium, designated strain BM62, was isolated from compost in the thermophilic stage in Harbin, China. Phylogenetic analysis based on the 16S rRNA gene indicated that strain BM62 belongs to the family Bacillaceae within the class Bacilli and was most closely related to Alteribacillus iranensis X5B (only 94.6% sequence similarity). Cells of strain BM62 were Gram-positive, rod-shaped, motile by periflagella, catalase-positive and oxidase-negative. Growth of strain BM62 was observed at salinities of 0-4% (optimum 2-3%), temperatures of 35-65 °C (optimum 50 °C) and pH values of 5-9 (optimum pH 7). The major cellular fatty acid was iso-C, and the predominant ubiquinone was MK-7. The peptidoglycan type is A1γ, and meso-diaminopimelic acid was the diagnostic diamino acid. The major polar lipids were diphosphatidylglycerol, phospholipid and phosphatidylglycerol. The G + C content of its genomic DNA was 36.5 mol%. Data from this polyphasic taxonomy study suggested that strain BM62 should be classified as the type strain of the type species of a new genus within the family Bacillaceae for which the name Aliibacillus thermotolerans gen. nov., sp. nov. is proposed. The type strain of the species Aliibacillus thermotolerans sp. nov. is BM62 (= DSM 101851 = CGMCC 1.15790). The respective DPD Taxon Number is GA00057.