title: Pleomorphomonas diazotrophica sp. nov., an endophytic N-fixing bacterium isolated from root tissue of Jatropha curcas L.
abstract: A novel aerobic, non-motile, pleomorphic, Gram-negative and nitrogen-fixing bacterial strain, designated R5-392(T), was isolated from surface-sterilized root tissue of Jatropha curcas. The organism grew optimally at 30 °C in media containing 1 % (w/v) NaCl and at pH 6.0-8.0. The predominant ubiquinone was Q-10 and the major fatty acids were C18 : 1ω7c/C18 : 1ω6c, C16 : 0 and C19 : 0 cyclo ω8c. The DNA G+C content was 63.2 mol%. Analysis of the 16S rRNA gene sequence suggested that strain R5-392(T) is affiliated with the order Rhizobiales within the class Alphaproteobacteria and is most closely related to Pleomorphomonas oryzae F-7(T) (98.8 % similarity) and Pleomorphomonas koreensis Y9(T) (98.3 % similarity). Analysis of partial nifH gene sequences also revealed a monophyletic lineage within the class Alphaproteobacteria, and strain R5-392(T) was most closely related to P. oryzae F-7(T) (98 %). Highest nitrogenase activity was detected in the presence of low-level organic nitrogen or in the presence of nitrogenase co-factors (Fe/Mo) in N-free media. Phenotypic and chemotaxonomic data suggest that strain R5-392(T) represents a novel species within the genus Pleomorphomonas, for which the name Pleomorphomonas diazotrophica sp. nov. is proposed. The type strain is R5-392(T) ( = KACC 16233(T) = DSM 25022(T)).
authors.affiliation: Biomaterials and Biocatalysts Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604.
authors.forename: Munusamy
authors.initials: M
authors.lastname: Madhaiyan
authors.affiliation: Raffles Institution, 1 Raffles Institution Lane, Singapore 575954.
authors.forename: Tan Yuan
authors.initials: TY
authors.lastname: Jin
authors.affiliation: Biomaterials and Biocatalysts Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604.
authors.forename: Joseph Jegan
authors.initials: JJ
authors.lastname: Roy
authors.affiliation: Korean Agricultural Culture Collection (KACC), Agricultural Microbiology Division, National Academy of Agricultural Science, Rural Development Administration (RDA), Suwon 441-707, Republic of Korea.
authors.forename: Soo-Jin
authors.initials: SJ
authors.lastname: Kim
authors.affiliation: Korean Agricultural Culture Collection (KACC), Agricultural Microbiology Division, National Academy of Agricultural Science, Rural Development Administration (RDA), Suwon 441-707, Republic of Korea.
authors.forename: Hang-Yeon
authors.initials: HY
authors.lastname: Weon
authors.affiliation: Korean Agricultural Culture Collection (KACC), Agricultural Microbiology Division, National Academy of Agricultural Science, Rural Development Administration (RDA), Suwon 441-707, Republic of Korea.
authors.forename: Soon-Wo
authors.initials: SW
authors.lastname: Kwon
authors.affiliation: Biomaterials and Biocatalysts Group, Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604.
authors.forename: Lianghui
authors.initials: L
authors.lastname: Ji
mesh_terms: D020561:Alphaproteobacteria / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D015373:Bacterial Typing Techniques; D001482:Base Composition; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000032:analysis; D031286:Jatropha / Q000382:microbiology*; D008969:Molecular Sequence Data; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000032:analysis; D010802:Phylogeny; D018517:Plant Roots / Q000382:microbiology; D011809:Quinones / Q000032:analysis; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D017422:Sequence Analysis, DNA
chemical_list: D004269:DNA, Bacterial; D005227:Fatty Acids; D011809:Quinones; D012336:RNA, Ribosomal, 16S; D009591:Nitrogenase