Pesticide bioremediation in liquid media using a microbial consortium and bacteria-pure strains isolated from a biomixture used in agricultural areas

• Published in: Ecotoxicology and environmental safety Vol. 200; p. 110734
• Main Authors: Góngora-Echeverría, Virgilio R., García-Escalante, Rodrigo, Rojas-Herrera, Rafael, Giácoman-Vallejos, Germán, Ponce-Caballero, Carmen
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.09.2020
• Subjects: 2,4-Dichlorophenoxyacetic Acid - metabolism; Agriculture; Atrazine - metabolism; Bacteria; Bacteria - isolation & purification; Bacteria - metabolism; Biobeds; Biodegradation, Environmental; Carbofuran - metabolism; Diazinon - metabolism; Glycine - analogs & derivatives; Glycine - metabolism; Glyphosate; Microbial Consortia; Microbial consortium; Pesticide degradation; Pesticides - metabolism; Pseudomonas - isolation & purification; Pure strains; Soil - chemistry; Soil Pollutants - metabolism; Pure strains; Biobeds; Bacteria; Microbial consortium; Pesticide degradation
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2020.110734

Microorganisms' role in pesticide degradation has been studied widely. Insitu treatments of effluents containing pesticides such as biological beds (biobeds) are efficient biological systems where biomixture (mixture of substrates) and microorganisms are the keys in pesticide treatment; however, microbial activity has been studied poorly, and its potential beyond biobeds has not been widely explored. In this study, the capacity of microbial consortium and bacteria-pure strains isolated from a biomixture (soil-straw; 1:1, v/v) used to treat agricultural effluents under real conditions were evaluated during a bioremediation process of five pesticides commonly used Yucatan Mexico. Atrazine, carbofuran, and glyphosate had the highest degradations (>90%) using the microbial consortium; 2,4-D and diazinon were the most persistent (DT50 = 8.64 and 6.63 days). From the 21 identified bacteria species in the microbial consortium, Pseudomonas nitroreducens was the most abundant (52%) according to identified sequences. For the pure strains evaluation 2,4-D (DT50 = 9.87 days), carbofuran (DT50 = 8.27 days), diazinon (DT50 = 8.80 days) and glyphosate (DT50 = 8.59 days) were less persistent in the presence of the mixed consortium (Ochrobactrum sp. DGG-1-3, Ochrobactrum sp. Ge-14, Ochrobactrum sp. B18 and Pseudomonas citronellolis strain ADA-23B). Time, pesticide, and strain type were significant (P < 0.05) in pesticide degradation, so this process is multifactorial. Microbial consortium and pure strains can be used to increase the biobed efficiency by inoculation, even in the remediation of soil contaminated by pesticides in agricultural areas. [Display omitted] •Consortium isolated from biomixture was efficient in pesticide degradation.•Pseudomonas nitroreducens was the most abundant bacteria (21 identified bacteria).•DT50 for 2,4-D, carbofuran & diazinon was lower in the mixed bacteria consortium.•Ochrobactrum sp. pure strain was better degrading atrazine & glyphosate.•Bacteria consortium showed a high potential in pesticide bioremediation process.