Serratia oryzae sp nov., isolated from rice stems

A novel endophytic bacterium, strain J11-6(T), was isolated from rice stems. Its taxonomic position was investigated using a polyphasic approach. The novel strain was Gram-staining-negative, facultatively anaerobic, motile and rod-shaped. Although the results of phylogenetic analysis based on 16S rRNA gene sequences indicated that J11-6(T) represented a member of the genus Rahnella, multilocus sequence analysis (MLSA) on the basis of concatenated partial atpD, gyrB, rpoB and infB gene sequences showed a clear distinction of J11-6(T) from the type strains of species of the genus Rahnella but indicated that it lay within the clade of the genus Serratia. The phylogenetically closest species were Serratia fonticola and Serratia aquatilis on the basis of the results of the MLSA phylogenetic analysis. The predominant cellular fatty acids were C-16 : 1 omega 7c (38.7 %) and C-16 : 0 (25.0 %). The DNA G+C content was 53.2 mol%. The DNA-DNA relatedness was 17.4% between J11-6(T) and Rahnella aquatilis CIP 78.65(T), and 29.2% between J11-6(T) and S. fonticola LMG 7882(T) which indicates that this strain represents a novel species of the genus Serratia. Characterization by genotypic and phenotypic analysis indicated that J11-6(T) (=ACCC 19934(T) = KCTC 52529(T)) represents a novel species of the genus Serratia, for which the name Serratia oryzae sp. nov. is proposed.