Oryzomicrobium terrae gen. nov., sp. nov., of the family Rhodocyclaceae isolated from paddy soil

A polyphasic approach was used to characterize a novel bacterium, designated strain TPP412T, isolated from a paddy soil in Taiwan. Strain TPP412T was Gram-stain-negative, facultatively anaerobic, rod-shaped, motile with a single polar flagellum and lacked bacteriochlorophyll. Growth was observed at 24–45 °C (optimal 25 °C), at pH 5.0–10.0 (optimal pH 7.0) and with 0–0.75 % (w/v) NaCl. Strain TPP412T showed highest 16S rRNA gene sequence similarity to members of the genera Rhodocyclus (94.1–94.5 %), Azospira (93.9–94.5 %) and Propionivibrio (93.4–94.4 %) and established a discrete taxonomic lineage in phylogenetic analysis. The major fatty acids found in strain TPP412T were C12 : 0, C12 : 0 3-OH, iso-C15 : 0 3-OH, C16 : 0, C16 : 1 ω7c/C16 : 1 ω6c and C18 : 1 ω7c/C18 : 1 ω6c. The major polar lipids consisted of phosphatidylmonomethylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and an unidentified lipid. The polyamine pattern showed a predominance of putrescine and a minor amount of spermidine. The DNA G+C content was 58.4 mol% and the predominant quinone system was ubiquinone-8 (Q-8). The low 16S rRNA gene sequence similarity values (≤94.5%) and distinct phylogenetic clustering clearly distinguished strain TPP412T from other representatives of the family Rhodocyclaceae . Based on the discrete phylogenetic, phenotypic and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence analysis, strain TPP412T is considered to represent a novel species of a new genus in the family Rhodocyclaceae , for which the name Oryzomicrobium terrae gen. nov., sp. nov. is proposed. The type strain of Oryzomicrobium terrae is TPP412T (=BCRC 80905T=JCM 30814T).