RESUMO
A Gram-stain-negative, non-motile and short-rod-shaped bacterium, designated as strain SY7T, was isolated from rhizosphere soil of the mangrove Kandelia obovata of Fugong village, in Zhangzhou, China. The isolate grew at 10-45 °C (optimum 30 °C), pH 6.0-10.0 (optimum pH 7.0) and 0-8% NaCl (optimum 3%, w/v). The 16S rRNA gene sequence and phylogenetic analysis revealed that strain SY7T located within the radiation of genus Nitratireductor and showed the highest sequence similarity of 97.23% to Nitratireductor pacificus MCCC 1A01024T. The DNA G+C content was 64.9%. In silico DNA-DNA hybridization and average nucleotide identity values between strain SY7T with reference strains of N. pacificus MCCC 1A01024T, N. basaltis KCTC 22119T and N. aquibiodomus DSM 15645T were 16.7%, 14.3%, 14.7% and 75.2%, 72.6%, 73.5%, respectively. The major isoprenoid quinone was Q-10. The dominant fatty acids were 11-methyl C18:1ω7c, iso-C17:0, C19:0ω8c cyclo and summed feature 8 (C18:1ω6c/C18:1ω7c), a profile that almost matched the other members of the genus Nitratireductor. The predominant polar lipids were phosphatidylcholine, phosphatidylglycerol, phosphatidylethanolamine, diphosphatidylglycerol. On the basis of the phenotypic, phylogenetic and chemotaxonomic analysis, strain SY7T represents a novel species of the genus Nitratireductor, for which the name Nitratireductor mangrovi sp. nov., is proposed. The type strain is SY7T (= KCTC 72110T = MCCC 1K03723T).