Antioxidant enzymes activities of Burkholderia spp. strains-oxidative responses to Ni toxicity.
Increased agriculture production associated with intense application of herbicides, pesticides, and fungicides leads to soil contamination worldwide. Nickel (Ni), due to its high mobility in soils and groundwater, constitutes one of the greatest problems in terms of environmental pollution. Metals, including Ni, in high concentrations are toxic to cells by imposing a condition of oxidative stress due to the induction of reactive oxygen species (ROS), which damage lipids, proteins, and DNA. This study aimed to characterize the Ni antioxidant response of two tolerant Burkholderia strains (one isolated from noncontaminated soil, SNMS32, and the other from contaminated soil, SCMS54), by measuring superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), and glutathione S-transferase (GST) activities. Ni accumulation and bacterial growth in the presence of the metal were also analyzed. The results showed that both strains exhibited different trends of Ni accumulation and distinct antioxidant enzymes responses. The strain from contaminated soil (SCMS54) exhibited a higher Ni biosorption and exhibited an increase in SOD and GST activities after 5 and 12 h of Ni exposure. The analysis of SOD, CAT, and GR by nondenaturing PAGE revealed the appearance of an extra isoenzyme in strain SCMS54 for each enzyme. The results suggest that the strain SCMS54 isolated from contaminated soil present more plasticity with potential to be used in soil and water bioremediation.
Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (USP), 13400-970, Piracicaba, SP, Brazil.
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Dourado
Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (USP), 13400-970, Piracicaba, SP, Brazil.
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Franco
Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (USP), 13400-970, Piracicaba, SP, Brazil.
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Peters
Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (USP), 13400-970, Piracicaba, SP, Brazil.
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Martins
Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (USP), 13400-970, Piracicaba, SP, Brazil.
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Souza
Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (USP), 13400-970, Piracicaba, SP, Brazil.
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Piotto
Departamento de Genética, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo (USP), 13400-970, Piracicaba, SP, Brazil. raa@usp.br.
R A
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Azevedo
D000975:Antioxidants / Q000378:metabolism*; D001673:Biodegradation, Environmental; D019117:Burkholderia / Q000187:drug effects* / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D009532:Nickel / Q000633:toxicity*; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000633:toxicity*; D013045:Species Specificity
D000975:Antioxidants; D012989:Soil Pollutants; D009532:Nickel
Antioxidant defense; Catalase; Glutathione reductase; Heavy metals; Oxidative stress; Rhizosphere bacteria; Superoxide dismutase