Zinc and lead detoxifying abilities of humic substances relevant to environmental bacterial species.
Ecotoxicol Environ Saf
; 151: 178-183, 2018 Apr 30.
Article
em En
| MEDLINE
| ID: mdl-29353168
ABSTRACT
The effect of humic substances (HS) and their different fractions (humic acids (HA) and hymatomelanic acids (HMA)) on the toxicity of zinc and lead to different strains of bacteria was studied. All tested bacteria demonstrated a lower resistance to zinc than lead showing minimum inhibitory concentrations of 0.1 - 0.3mM and 0.3-0.5mM, respectively. The highest resistance to lead was characteristic of Pseudomonas chlororaphis PCL1391 and Rhodococcus RS67, while Pseudomonas chlororaphis PCL1391 showed the greatest resistance to zinc. The combined fractions of HS and HA alone reduced zinc toxicity at all added concentrations of the organic substances (50 - 200mgL-1) to all microorganisms, while hymatomelanic acids reduced zinc toxicity to Pseudomonas chlororaphis PCL1391 at 200mgL-1 organic concentration only. The HS fractions imparted similar effects on lead toxicity also. This study demonstrated that heavy metal toxicity to bacteria could be reduced through complexation with HS and their fractions. This was particularly true when the metal-organic complexes held a high stability, and low solubility and bioavailability.
Palavras-chave
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Zinco
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Inativação Metabólica
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Substâncias Húmicas
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Chumbo
Idioma:
En
Revista:
Ecotoxicol Environ Saf
Ano de publicação:
2018
Tipo de documento:
Article