Microbaculum mangrovi sp. nov., isolated from mangrove sediment

A Gram-stain-negative, strictly aerobic and motile bacterium, designated as FT89 T , was isolated from mangrove sediment in Shenzhen, China. Phylogenetic analysis of strain FT89 T was mostly related to Microbaculum marinisediminis , with 16S rRNA gene similarity of 99.66%. The genome size of strain FT89 T was 5,065,293 bp and the calculated G+C molar content was 65.90mol%. The average nucleotide identity (ANI) and digital DNA–DNA hybridization (dDDH) value towards M. marinisediminis yielded 93.86% ANI and 53.2% dDDH. Although the 16S rRNA gene similarity is above 98.7%, the ANI and dDDH values are below the established species delineation thresholds (ANI <95% and dDDH <70%). Here, we confirm that strain FT89 T represents a novel species. Phenotypic characterization revealed that cells of strain FT89 T were ovoid to rod shaped, measuring 0.3–0.7 µm in width and 0.9–3.2 µm in length. Strain FT89 T grew at 20–40 °C (optimum 35 °C) at pH 5.5–9.0 (optimum pH 6.0–7.0) with 0–9% (w/v) NaCl (optimum 1–2%). The cells of strain FT89 T contained Q-10, and the major cellular fatty acids were composed of C 19:0 cyclo ω 8 c (41.7%) and summed feature 8 (C 18:1 ω 7 c and/or C 18:1 ω 6 c ) (32.4%). Based on phylogenetic, phenotypic and chemotaxonomic analysis, strain FT89 T should represent a novel species of the genus Microbaculum , for which the proposed name is Microbaculum mangrovi FT89 T (=MCCC 1K08485 T =KCTC 8079 T ).