INVESTIGADORES
FUENTES Maria Soledad
artículos
Título:
Chlorpyrifos biodegradation and 3,5,6-trichloro-2-pyridinol production by actinobacteria isolated from soil
Autor/es:
BRICEÑO, GABRIELA E.; FUENTES, MARÍA S.; PALMA, GRACIELA; JORQUERA, M. A.; AMOROSO, MARÍA J.; DIEZ, MARÍA C.
Revista:
INTERNATIONAL BIODETERIORATION & BIODEGRADATION
Editorial:
ELSEVIER SCI LTD
Referencias:
Año: 2012 vol. 73 p. 1 - 7
ISSN:
0964-8305
Resumen:
Chlorpyrifos (CP) is a widely used agricultural insecticide that is hazardous to both the environment and human health. Therefore, it is an essential to develop approaches to remove this compound from contaminated soils, water and sediments. In this study, actinobacteria were isolated from an agricultural soil that had received continuous applications of CP. Four strains were selected as a result of their tolerance to 50 mg L1 of CP in agar plate and they were identified as Streptomyces sp. based on 16S rDNA. According to relationship of CP degradation and microbial growth studies, two isolates were selected and were named Streptomyces sp. strain AC5 and Streptomyces sp. strain AC7. The strains were cultivated in liquid medium with CP at concentrations of 25 mg L1 and 50 mg L1 for 72 h. The results indicated that both strains were able to rapidly degrade CP with about 90% degradation after 24 h of incubation. A different pattern of CP degradation was observed when its main metabolite, 3,5,6-trichloro-2-pyridinol (TCP) was monitored. A maximum concentration of 0.46 mg L1 of TCP was produced by Streptomyces sp. strain AC5 and its concentration decreased as a function of time. In contrast, TCP production by Streptomyces sp. AC7 increased over time from 1.31 mg L1 to 4.32 mg L1. CP degradation was associated to microbial growth of the strains, pH modification, glucose consumption and organic acids excretion in the liquid medium. This work constitutes one of the few reports of Streptomyces as CP-degraders. Given the high CP degradation observed here, the Streptomycetes strains show a good potential as CP-degrading actinobacteria.