title: Anaerobic bio-removal of uranium (VI) and chromium (VI): comparison of microbial community structure.
abstract: Several microbial communities, obtained from uranium contaminated and non-contaminated samples, were investigated for their ability to remove uranium (VI) and the cultures capable for this removal were further assessed on their efficiency for chromium (VI) removal. The highest efficiency for removal of both metals was observed on a consortium from a non-contaminated soil collected in Monchique thermal place, which was capable to remove 91% of 22 mg L(-1) U(VI) and 99% of 13 mg L(-1) Cr(VI). This study revealed that uranium (VI) removing communities have also ability to remove chromium (VI), but when uranium (VI) was replaced by chromium (VI) several differences in the structure of all bacterial communities were observed. TGGE and phylogenetic analysis of 16S rRNA gene showed that the uranium (VI) removing bacterial consortia are mainly composed by members of Rhodocyclaceae family and Clostridium genus. On the other hand, bacteria from Enterobacteriaceae family were detected in the community with ability for chromium (VI) removal. The existence of members of Enterobacteriaceae and Rhodocyclaceae families never reported as chromium or uranium removing bacteria, respectively, is also a relevant finding, encouraging the exploitation of microorganisms with new abilities that can be useful for bioremediation.
authors.affiliation: Centro de Ciências do Mar, Universidade do Algarve, Campus de Gambelas, 8005-139 Faro, Portugal.
authors.forename: Mónica
authors.initials: M
authors.lastname: Martins
authors.forename: Maria Leonor
authors.initials: ML
authors.lastname: Faleiro
authors.forename: Sandra
authors.initials: S
authors.lastname: Chaves
authors.forename: Rogério
authors.initials: R
authors.lastname: Tenreiro
authors.forename: Erika
authors.initials: E
authors.lastname: Santos
authors.forename: Maria Clara
authors.initials: MC
authors.lastname: Costa
mesh_terms: D001421:Bacteria, Anaerobic / Q000302:isolation & purification / Q000378:metabolism*; D001673:Biodegradation, Environmental; D002857:Chromium / Q000378:metabolism*; D003013:Clostridium / Q000302:isolation & purification / Q000378:metabolism; D004755:Enterobacteriaceae / Q000302:isolation & purification / Q000378:metabolism; D010802:Phylogeny; D043362:Rhodocyclaceae / Q000302:isolation & purification / Q000378:metabolism; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000378:metabolism*; D012990:Soil Pollutants, Radioactive / Q000378:metabolism; D014501:Uranium / Q000378:metabolism*
chemical_list: D012989:Soil Pollutants; D012990:Soil Pollutants, Radioactive; D002857:Chromium; C074702:chromium hexavalent ion; D014501:Uranium