title: Pontibacter diazotrophicus sp. nov., a novel nitrogen-fixing bacterium of the family Cytophagaceae.
abstract: Few diazotrophs have been found to belong to the family Cytophagaceae so far. In the present study, a Gram-negative, rod-shaped bacterium that forms red colonies, was isolated from sands of the Takalamakan desert. It was designated H4XT. Phylogenetic and biochemical analysis indicated that the isolate is a new species of the genus Pontibacter. The 16S rRNA gene of H4XT displays 94.2-96.8% sequence similarities to those of other strains in Pontibacter. The major respiratory quinone is menaquinone-7 (MK-7). The DNA G+C content is 46.6 mol%. The major cellular fatty acids are iso-C15∶0, C16∶1ω5c, summed feature 3 (containing C16∶1ω6c and/or C16∶1ω7c) and summed feature 4 (comprising anteiso-C17∶1B and/or iso-C17∶1I). The major polar lipids are phosphatidylethanolamine (PE), one aminophospholipid (APL) and some unknown phospholipids (PLs). It is interesting to see that this bacterium can grow very well in a nitrogen-free medium. PCR amplification suggested that the bacterium possesses at least one type of nitrogenase gene. Acetylene reduction assay showed that H4XT actually possesses nitrogen-fixing activity. Therefore, it can be concluded that H4XT is a new diazotroph. We thus referred it to as Pontibacter diazotrophicus sp. nov. The type strain is H4XT ( = CCTCC AB 2013049T = NRRL B-59974T).
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China; School of Chemical and Material Engineering, Hubei Polytechnic University, Huangshi, China.
authors.forename: Linghua
authors.initials: L
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China.
authors.forename: Xian-Chun
authors.initials: XC
authors.lastname: Zeng
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China.
authors.forename: Yao
authors.initials: Y
authors.lastname: Nie
authors.affiliation: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, China.
authors.forename: Xuesong
authors.initials: X
authors.lastname: Luo
authors.affiliation: Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, and Laboratory for Conservation and Utilization of Bio-resources, Yunnan Institute of Microbiology, Yunnan University, Kunming, China.
authors.forename: Enmin
authors.initials: E
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China.
authors.forename: Lingli
authors.initials: L
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Biogeology and Environmental Geology & Department of Biological Science and Technology, School of Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China.
authors.forename: Yunfan
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Key Laboratory of Microbial Diversity in Southwest China, Ministry of Education, and Laboratory for Conservation and Utilization of Bio-resources, Yunnan Institute of Microbiology, Yunnan University, Kunming, China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Li
mesh_terms: D015373:Bacterial Typing Techniques; D041964:Cytophagaceae / Q000145:classification* / Q000235:genetics / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000378:metabolism*; D009586:Nitrogen Fixation; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics
chemical_list: D004269:DNA, Bacterial; D005227:Fatty Acids; D012336:RNA, Ribosomal, 16S