Rhizobium rhizosphaerae sp. nov., a novel species isolated from rice rhizosphere.
Two novel, Gram-negative, motile, rod-shaped, aerobic bacterial strains, MH17Tand RD15, were isolated from the sterilized root and rhizosphere soil of rice, respectively. Phylogenetic analysis based on 16S rRNA gene sequences showed that the similarity between strains MH17Tand RD15 was 100%. The isolates exhibit high sequence similarities to Rhizobium oryzae CGMCC 1.7048T(98.7%) and Rhizobium petrolearium SL-1T(97.0% and 97.1%), which supports that they belong to a novel species in the genus Rhizobium. Strains MH17Tand RD15 exhibited growth at 15-45 °C, pH 5.0-11.0, 0-2.0% sodium chloride (w/v). Sequence analysis of housekeeping genes gyrB, recA, atpD, ropB, gltA showed that these two novel strains had less than 94% similarity with the known species, indicating the distinct position of MH17Tand RD15 in the genus Rhizobium. The major cellular fatty acids were identified as summed feature 8 (C18:1ω7c and/or C18:1ω6c). Type strain MH17Thad 87.5% DNA-DNA relatedness with RD15 by using the initial renaturation rate method. Based on draft genome sequences, strain MH17Tshowed 30.1% DNA-DNA hybridization values to R. oryzae CGMCC 1.7048T, the closely related strain, which supported that MH17Trepresents a novel species in the genus Rhizobium. Average nucleotide identity (ANI) between strains MH17Tand RD15 were 97.8%, and strain MH17Tshowed 82.2% ANI value with R. oryzae CGMCC 1.7048T. The DNA G+C content was 60.4 mol% (Tm). Based on physiological, biochemical characteristic, genotypic data, strains MH17Tand RD15 are concluded to represent a new species within the genus Rhizobium, for which the name Rhizobium rhizosphaerae sp. nov. is proposed. The type strain is MH17T(=ACCC 19963T= KCTC 52414T).
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
Juan-Juan
JJ
Zhao
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
Jun
J
Zhang
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
Rui-Jie
RJ
Zhang
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China.
Cai-Wen
CW
Zhang
School of Minerals Processing and Bioengineering, Central South University, Changsha, 410083, People's Republic of China.
Hua-Qun
HQ
Yin
Key Laboratory of Microbial Resources Collection and Preservation, Ministry of Agriculture, Institute of Agricultural Resources and Regional Planning, Chinese Academy of Agricultural Sciences, Beijing, 100081, People's Republic of China. zhangxiaoxia@caas.cn.
Xiao-Xia
XX
Zhang
D000332:Aerobiosis; D001426:Bacterial Proteins / Q000235:genetics; D015373:Bacterial Typing Techniques; D001482:Base Composition; D016000:Cluster Analysis; D003600:Cytosol / Q000737:chemistry; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D020043:Genes, Essential; D006863:Hydrogen-Ion Concentration; D008124:Locomotion; D009693:Nucleic Acid Hybridization; D012275:Oryza / Q000254:growth & development; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D012231:Rhizobium / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification* / Q000502:physiology; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D013696:Temperature
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S
Polyphasic taxonomy; Rhizobium rhizosphaerae sp. nov.; Root of rice