Aislamiento, identificación y caracterización de cepas bacterianas con potencial de degradación de los plaguicidas clorotalonil y clorpirifos
Fecha
2023
Autores
Estrada Gamboa, Joyce María
Umaña Castro, Rodolfo
Sancho Blanco, Carolina
Orozco Aceves, Martha
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Editor
Universidad Nacional, Costa Rica
Resumen
El uso indiscriminado de plaguicidas altamente tóxicos en la agricultura ha producido contaminación de los suelos y deterioro de los ecosistemas. Una solución prometedora para este problema ambiental es la biorremediación, que incluye el uso de bacterias para degradar sustancias contaminantes, incluidos los plaguicidas. [Objetivo] El presente trabajo tuvo por objetivo el aislamiento, identificación y caracterización de cepas bacterianas con capacidad de degradar los plaguicidas clorotalonil y clorpirifos, para su potencial uso en la biorremediación de suelos contaminados. [Metodología] Las cepas fueron aisladas de suelos agrícolas mediante cultivos de enriquecimiento, que contenían clorotalonil o clorpirifos (20 mg/L) como única fuente de carbono. Las cepas aisladas se caracterizaron por su morfología, fisiológicamente por su respuesta a 48 pruebas bioquímicas y frente a 15 antibióticos, cinética de crecimiento, y molecularmente (amplificación del gen 16S). [Resultados] Se aisló una cepa bacteriana capaz de utilizar (y degradar) clorpirifos como fuente de carbono, identificada como Stenotrophomonas maltophilia y dos cepas bacterianas con capacidad parcial de utilizar clorotalonil como fuente de carbono, identificadas como Enterobacter cloacae y Ochrobactrum anthropi. Las tres especies bacterianas son bacilos Gram negativo y presentaron características fisiológicas diversas, incluyendo resistencia variable a ciertos antibióticos. [Conclusión] Se concluye que las bacterias aisladas tienen potencial biotecnológico para ser incorporadas en una estrategia de biorremediación de suelos contaminados, especialmente para eliminación de clorpirifos. Finalmente, se plantean perspectivas de investigación a futuro para dilucidar procesos más eficientes de degradación de clorotalonil mediante cometabolismo.
The indiscriminate use of highly toxic pesticides in agriculture has produced soil contamination and deterioration of ecosystems. A promising solution to this environmental problem is bioremediation, which includes the use of bacteria to degrade pollutants, including pesticides. [Objective] The objective of this work was the isolation, identification, and characterization of bacterial strains capable of degrading the pesticides chlorothalonil and chlorpyrifos, to determine their potential use in the bioremediation of contaminated soils. [Methodology] The strains were isolated from agricultural soils using enrichment cultures containing chlorothalonil or chlorpyrifos (20 mg/L) as sole carbon source. The isolated strains were characterized by their morphology, physiologically by their response to 48 biochemical tests and sensitivity to 15 antibiotics. Additionally, the growth kinetics, and molecular characterization (amplification of the 16S gene) of strains were determined. [Results] In total, three strains were isolated, one capable of using (and degrading) chlorpyrifos, identified as Stenotrophomonas maltophilia, and two bacterial strains with partial ability to use chlorothalonil as a carbon source, identified as Enterobacter cloacae and Ochrobactrum anthropi. The three bacterial species are Gram-negative rods and have diverse physiological characteristics, including variable resistance to certain antibiotics. [Conclusion] It is concluded that the isolated bacteria have biotechnological potential to be incorporated into a bioremediation strategy for contaminated soils, especially for the elimination of chlorpyrifos. Finally, future research perspectives are proposed to elucidate more efficient processes of chlorothalonil degradation by cometabolism.
The indiscriminate use of highly toxic pesticides in agriculture has produced soil contamination and deterioration of ecosystems. A promising solution to this environmental problem is bioremediation, which includes the use of bacteria to degrade pollutants, including pesticides. [Objective] The objective of this work was the isolation, identification, and characterization of bacterial strains capable of degrading the pesticides chlorothalonil and chlorpyrifos, to determine their potential use in the bioremediation of contaminated soils. [Methodology] The strains were isolated from agricultural soils using enrichment cultures containing chlorothalonil or chlorpyrifos (20 mg/L) as sole carbon source. The isolated strains were characterized by their morphology, physiologically by their response to 48 biochemical tests and sensitivity to 15 antibiotics. Additionally, the growth kinetics, and molecular characterization (amplification of the 16S gene) of strains were determined. [Results] In total, three strains were isolated, one capable of using (and degrading) chlorpyrifos, identified as Stenotrophomonas maltophilia, and two bacterial strains with partial ability to use chlorothalonil as a carbon source, identified as Enterobacter cloacae and Ochrobactrum anthropi. The three bacterial species are Gram-negative rods and have diverse physiological characteristics, including variable resistance to certain antibiotics. [Conclusion] It is concluded that the isolated bacteria have biotechnological potential to be incorporated into a bioremediation strategy for contaminated soils, especially for the elimination of chlorpyrifos. Finally, future research perspectives are proposed to elucidate more efficient processes of chlorothalonil degradation by cometabolism.
Descripción
Parte del Programa: Fortalecimiento del Área de Diagnóstico para el soporte de las actividades permanentes del IRET SIA 0043-17
Palabras clave
CONTAMINACIÓN DEL SUELO, BACTERIAS, FUNGICIDAS, INSECTICIDAS, CONTROL DE PLAGAS, SOIL POLLUTION, BACTERIA, FUNGICIDES, INSECTICIDES, PEST CONTROL