title: During stationary phase, Beijerinckia derxii shows nitrogenase activity concomitant with the release and accumulation of nitrogenated substances.
abstract: Beijerinckia derxii, a free-living nitrogen-fixing bacterium, maintained an increasing nitrogenase specific activity during the stationary growth phase. To verify the destination of the nitrogen fixed during this phase, intra and extracellular nitrogenated contents were analyzed. Organic nitrogen and amino acids were detected in the supernatant of the cultures. An increase in intracellular content of both nitrogen and protein occurred. Cytoplasmic granules indicated the presence of arginine. The ability of a non-diazotrophic bacterium (E. coli) to use B. derxii proteins as a source of nitrogen was observed concomitantly with E. coli growth. There is a suggestion that B. derxii contributes to the environment by both releasing nitrogenated substances and accumulating substances capable of being consumed after its death.
authors.affiliation: Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo. Av. Prof. Lineu Prestes, 1374, CEP-05508-900, São Paulo, Brasil.
authors.forename: Natália Reiko Sato
authors.initials: NR
authors.lastname: Miyasaka
authors.forename: Daniela Strauss
authors.initials: DS
authors.lastname: Thuler
authors.forename: Eny Iochevet Segal
authors.initials: EI
authors.lastname: Floh
authors.forename: Walter
authors.initials: W
authors.lastname: Handro
authors.forename: Mariana Braga Duarte
authors.initials: MB
authors.lastname: Toledo
authors.forename: Sônia Maria
authors.initials: SM
authors.lastname: Gagioti
authors.forename: Heloiza Ramos
authors.initials: HR
authors.lastname: Barbosa
mesh_terms: D042062:Beijerinckiaceae / Q000201:enzymology* / Q000254:growth & development*; D015169:Colony Count, Microbial; D003470:Culture Media; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism*; D009586:Nitrogen Fixation; D009591:Nitrogenase / Q000378:metabolism*; D011506:Proteins / Q000378:metabolism
chemical_list: D003470:Culture Media; D011506:Proteins; D009591:Nitrogenase; D009584:Nitrogen