Ruficoccus amylovorans gen. nov., sp. nov., an amylolytic and nitrate-reducing diazotroph of the family Puniceicoccaceae

A novel amylolytic, nitrate-reducing and diazotrophic bacterium, designated strain CC-MHH0563T, isolated from a fermenter was assessed for its taxonomic status using a polyphasic approach. Cells of strain CC-MHH0563T were Gram-staining-negative, catalase- and oxidase-positive, mesophilic and aerobic cocci, which produced reddish nondiffusible pigments. Growth was observed at 15-37 °C (optimal 25 °C), pH 6.0-8.0 (optimal pH 7.0) and salinity of 0-3 % (w/v). Strain CC-MHH0563T showed highest pairwise 16S rRNA gene sequence similarity to members of the genera Cerasicoccus(89.3-89.5 %), Coraliomargarita (87.8 %), Pelagicoccus(85.8-86.4 %) and Puniceicoccus (87.9 %), and established a discrete taxonomic lineage during phylogenetic analysis. The major fatty acids found in strain CC-MHH0563T were C14 : 0, anteiso-C15 : 0, C16 : 0, C17 : 0, C18 : 0 and C18 : 1ω9c. The polar lipid profile consisted of phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, two unknown aminolipids and two unknown aminophospholipids. The polyamine pattern showed a predominance of spermidine and a minor amount of cadaverine. The DNA G+C content was 57.4 mol% and the predominant quinone system was menaquinone-7. The low 16S rRNA gene sequence similarity values (<90.0 %) and a distinct phylogenetic clustering clearly distinguished strain CC-MHH0563T from other representatives of the family Puniceicoccaceae. Based on the discrete phylogenetic, phenotypic and chemotaxonomic traits together with the results of comparative 16S rRNA gene sequence analysis, strain CC-MHH0563T is considered to represent a novel genus and species of the family Puniceicoccaceae, for which the name Ruficoccus amylovorans gen. nov., sp. nov. is proposed. The type strain of the type species is CC-MHH0563T (=BCRC 80918T=JCM 31066T).