Downloaded from www.microbiologyresearch.org by IP: 54.70.40.11 On: Thu, 07 Feb 2019 02:18:07 Rhizobium straminoryzae sp. nov., isolated from the surface of rice straw Shih-Yao Lin, 1 Yi-Han Hsu, 1 You-Cheng Liu, 1 Mei-Hua Hung, 1 Asif Hameed, 1 Wei-An Lai, 1,2 Wen-Shao Yen 1 and Chiu-Chung Young 1,2 Correspondence Chiu-Chung Young ccyoung@mail.nchu.edu.tw 1 Department of Soil and Environmental Sciences, College of Agriculture and Natural Resources, National Chung Hsing University, Taichung, Taiwan 2 Agricultural Biotechnology Center, National Chung Hsing University, Taichung, Taiwan An aerobic, Gram-stain-negative, rod-shaped bacterium, designated strain CC-LY845 T , was isolated from the surface of rice straw in Taiwan. Cells were non-motile, and no flagellum was detected. Comparison of 16S rRNA gene sequences indicated that the strain was phylogenetically related to species of the genus Rhizobium, with closest similarity to Rhizobium pseudoryzae KCTC 23294 T (97.6 %), R. rhizoryzae KCTC 23652 T (97.0 %) and R. oryzae LMG 24253 T (96.7 %); other species showed lower levels of similarity (,96.6 %). The DNA–DNA relatedness of strain CC-LY845 T and R. pseudoryzae KCTC 23294 T was 34.8±3.1 % (reciprocal value 39.2±2.2 %). Phylogenetic analysis based on the housekeeping atpD and recA genes showed that the novel strain could be distinguished from R. pseudoryzae KCTC 23294 T (92.7 and 91.5 %, respectively) and other species of the genus Rhizobium. The temperature range for growth was 25–42 6C, the pH range was 5.0–9.0 and NaCl concentrations up to 4.0 % (w/v) were tolerated. Strain CC-LY845 T did not form nodules on four different legumes, and the nodD and nifH genes were not detected by PCR. The major fatty acids were C 16 : 0 and summed feature 8 (C 18 : 1 v7c/C 18 : 1 v6c). The polyamine pattern of strain CC-LY845 T showed spermidine and putrescine as major polyamines. The predominant quinone system was ubiquinone 10 (Q-10). The DNA G+C content was 68.3±2.4 mol%. Base on its phylogenetic, phenotypic and chemotaxonomic features, strain CC-LY845 T is proposed to represent a novel species within the genus Rhizobium, for which the name Rhizobium straminoryzae sp. nov. is proposed. The type strain is strain CC-LY845 T (5BCRC 80698 T 5JCM 19536 T ). Members of the genus Rhizobium are traditionally con- sidered as legume endosymbionts and have generally been isolated from nodules on leguminous plants. Large popula- tions of rhizobia are found both in the bulk soil and in the rhizospheres of legumes and other plants (Schloter et al., 1997; Segovia et al., 1991; Sullivan et al., 1996). Since the description of the genus Rhizobium to accommodate root and/or stem-nodule bacteria by Frank (1889), there have been a number of revisions to its description and the addition of many novel species. More recently, novel species of the genus have also been found in different environments, such as Rhizobium selenitireducens and R. daejeonense isolated from bioreactors (Quan et al., 2005; Hunter et al., 2007), Rhizobium cellulosilyticum from sawdust of Populus alba (Garcı ´a-Fraile et al., 2007), Rhizobium oryzae from wild rice (Peng et al., 2008) and strains of Rhizobium alamii from the rhizosphere of sunflowers (Berge et al., 2009). Young et al. (2001) proposed new combinations for all species of Agrobacterium (Conn, 1942) and Allorhizobium undicola (de Lajudie et al., 1998) within the genus Rhizobium; the transfer of the species Agrobacterium rhizogenes, A. rubi, A. tumefaciens and A. vitis to Rhizobium was described. Nevertheless, Farrand et al. (2003) supported the position that the genus Agrobacterium is a proper name for this group of pathogenic rhizobial species. Recently, a novel genus ‘Neorhizobium’ was proposed as the result of an investigation of the phylogenetic relatedness of the Rhizobium galegae complex and members of the genus Agrobacterium (Mousavi et al., 2014), although this name has not been validly published at the time of writing. While investigating the bacterial diversity of the plant surface, a strain designated CC-LY845 T was isolated from rice straw. In brief, split rice straw was introduced into sterile water and shaken at 30 u C for 30 min. Subsequently, this sample was spread-plated (100 ml per plate) on nutrient The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA, atpD and recA gene sequences of strain CC-LY845 T are KF444510, KJ863419 and KJ863426, respectively. Three supplementary figures are available with the online version of this paper. International Journal of Systematic and Evolutionary Microbiology (2014), 64, 2962–2968 DOI 10.1099/ijs.0.062117-0 2962 062117 G 2014 IUMS Printed in Great Britain