title: Adaptive responses of chemolithoautotrophic acidophilic Acidithiobacillus ferrooxidans to sewage sludge.
abstract: OBJECTIVE
  The aim of the present study was to investigate the phenotypic and genotypic variability of two strains of Acidithiobacillus ferrooxidans genus during growth in sewage sludge.
  
  
  RESULTS
  Compared with A. ferrooxidans cells grown in mineral medium, those grown in sewage sludge demonstrated remarkable changes in ultrastructure (transmission electron microscopy) and significantly elongated lag phases. These latter cells also lacked carboxysomes and rusticyanin, showed lower level of cytochromes and exhibited modifications to their outer membrane proteins (SDS-PAGE). Restriction fragment length polymorphism analysis using pulsed-field gel electrophoresis showed that most restriction fragments were highly conserved and shared by strains grown under different conditions. However, in relation to cells grown in mineral medium, sludge-grown A. ferrooxidans lacked a number of restriction fragments, clearly indicating structural changes to the chromosomal DNA of the organism.
  
  
  CONCLUSIONS
  In combination, the results of this study provide evidence of adaptive responses by chemolithoautotrophic acidophilic A. ferrooxidans to facilitate growth in sewage sludge.
  
  
  CONCLUSIONS
  The obtained results are important from scientific as well as industrial application point of view, because they confirmed that A. ferrooxidans highly sensitive to organic compounds bacteria is useful in biotechnologies of heavy metal removal from shale ore, polluted soils and sewage sludge containing organic hazardous compounds.
authors.affiliation: Laboratory of Environmental Pollution Analysis, Faculty of Biology, Warsaw University, Warsaw, Poland.
authors.forename: R
authors.initials: R
authors.lastname: Matlakowska
authors.forename: A
authors.initials: A
authors.lastname: Sklodowska
mesh_terms: D042763:Acidithiobacillus / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D000220:Adaptation, Biological; D001426:Bacterial Proteins / Q000032:analysis; D002876:Chromosomes, Bacterial / Q000235:genetics; D003470:Culture Media; D003580:Cytochromes / Q000032:analysis; D004269:DNA, Bacterial / Q000235:genetics; D005838:Genotype; D008854:Microscopy, Electron / Q000379:methods; D008903:Minerals; D010641:Phenotype; D012150:Polymorphism, Restriction Fragment Length; D012722:Sewage / Q000737:chemistry / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; D003470:Culture Media; D003580:Cytochromes; D004269:DNA, Bacterial; D008903:Minerals; D012722:Sewage