Chromobacterium rhizoryzae sp nov., isolated from rice roots

A novel facultatively anaerobic, rod-shaped bacterium, designated LAM1188(T), was isolated from the roots of rice (Oryzasativa) in Hubei Province. Cells of LAM1188(T) were Gram-stain-negative and motile. The temperature and pH ranges for growth were 15-40 degrees C (optimum: 30 degrees C) and pH 5-10 (optimum: pH 7), respectively. The strain did not require NaCl for growth but tolerated up to 3.5% NaCl (w/v). Analysis of the 16S rRNA gene sequence indicated that the isolate represented a member of the genus Chromobacterium, and was most closely related to Chromobacterium haemolyticum MDA0585(T) and Chromobacterium aquaticum CC-SEYA-1(T) with 98.7% and 97.3% sequence similarity, respectively. The values of DNA-DNA hybridization between LAM1188(T) and C. haemolyticum JCM 14163(T) and C. aquaticum CCUG 55175(T) were 54.0 +/- 2.1% and 44.0 +/- 1.2 %, respectively. The major cellular fatty acids were C-16:0 and summed feature 3 (C-16:1 omega 6c and/or C-16:1 omega 7c). The main polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, four unidentified aminolipids and four unidentified lipids. The respiratory quinone was ubiquinone Q-8. The DNA G+C content was 64.1 mol% as determined by the T-m method. On the basis of its phenotypic, chemotaxonomic and phylogenetic characteristics, strain LAM1188(T) is suggested to represent a novel species of the genus Chromobacterium, for which the name Chromobacte riumrhizoryzae sp. nov. is proposed. The type strain is LAM1188(T) (= ACCC 19900(T) = JCM 31180(T)).