Removal of heavy metals by exopolymeric substances produced by resistant purple nonsulfur bacteria isolated from contaminated shrimp ponds
Electron. j. biotechnol
;
14(4): 2-2, July 2011. ilus, tab
Artigo
em Inglês
| LILACS
| ID: lil-640497
ABSTRACT
Two purple nonsulfur bacteria (PNSB) strains, Rhodobium marinum NW16 and Rhodobacter sphaeroides KMS24 were investigated for their potential to remove heavy metals (HMs) from contaminated shrimp pond water. Tolerance of both PNSB strains growing with both microaerobic-light and aerobic-dark conditions, based on their minimum inhibitory concentrations, was in the order of Cu2+ > Zn2+ > Cd2+ (Pb precipitation occurred at 0.34 mM). Results from a scanning electron microscope equipped with an energy dispersive X-ray spectrometer (SEM-EDX) indicated that Cu2+ and Zn2+ altered the cellular morphology of both strains and accumulated HMs were found in their cells. The highest amounts of both cations were found in their cell walls followed by the cytoplasm and cell membrane. Using the highest concentrations (mM) of HMs found in shrimp pond of 0.0067 Cd2+, 0.54 Cu2+, 0.30 Pb2+, 0.89 Zn2+ and 3 percent NaCl under both incubating conditions exopolymeric substances (EPS) produced by both strains showed a greater removal of all HMs (average percentages; 90.52-97.29) than their cells (average percentages; 14.02-75.03).
Texto completo:
DisponíveL
Índice:
LILACS (Américas)
Assunto principal:
Polímeros
/
Bactérias
/
Aquicultura
/
Metais Pesados
/
Poluição Ambiental
Idioma:
Inglês
Revista:
Electron. j. biotechnol
Assunto da revista:
Biotecnologia
Ano de publicação:
2011
Tipo de documento:
Artigo
/
Documento de projeto
País de afiliação:
Austrália
/
Tailândia
Instituição/País de afiliação:
Prince of Songkla University/TH
/
University of South Australia/AU
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