title: Differential expression of nifH and anfH genes in Paenibacillus durus analysed by reverse transcriptase-PCR and denaturing gradient gel electrophoresis.
abstract: OBJECTIVE
  The aim of this study was to develop an approach based on a reverse transcriptase (RT)-PCR/denaturing gradient gel electrophoresis (DGGE) for the detection of the functional genes nifH and anfH in Paenibacillus durus.
  
  
  RESULTS
  Two sets of primers were employed to study the expression of the nitrogen fixation genes in a pure-culture system of P. durus grown in media with increasing concentrations of ammonium (NH(4)(+)), tungsten (W) or molybdenum (Mo). The results obtained indicate that the expression of nitrogenase genes from P. durus can take place in the presence of relatively high levels of fixed nitrogen. It was also observed that the addition of 20 micromol l(-1) molybdenum and 2 mmol l(-1) tungstate did not interfere in the mRNA levels of nifH and anfH genes.
  
  
  CONCLUSIONS
  Our results demonstrate the presence and transcription of nifH and anfH in P. durus under a variety of growth conditions. A specific set of primers was designed for the detection of the alternative system for nitrogen fixation in P. durus.
  
  
  CONCLUSIONS
  The RT-PCR/DGGE system enables the rapid gathering of incremental data about the regulation of conventional and alternative nitrogenase genes in P. durus strains.
authors.affiliation: Instituto de Microbiologia Prof. Paulo de Góes, Universidade Federal do Rio de Janeiro, Ilha do Fundão, Rio de Janeiro, Brasil.
authors.forename: R L F
authors.initials: RL
authors.lastname: Teixeira
authors.forename: I
authors.initials: I
authors.lastname: von der Weid
authors.forename: L
authors.initials: L
authors.lastname: Seldin
authors.forename: A S
authors.initials: AS
authors.lastname: Rosado
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D003470:Culture Media; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D015964:Gene Expression Regulation, Bacterial; D016936:Gram-Positive Endospore-Forming Bacteria / Q000145:classification / Q000235:genetics / Q000254:growth & development* / Q000378:metabolism; D008982:Molybdenum / Q000378:metabolism; D009586:Nitrogen Fixation; D010088:Oxidoreductases / Q000235:genetics / Q000378:metabolism*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods*; D014414:Tungsten / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D000644:Quaternary Ammonium Compounds; D008982:Molybdenum; D010088:Oxidoreductases; C029130:nitrogenase reductase; D014414:Tungsten