Pesticide-tolerant bacteria isolated from a biopurification system to remove commonly used pesticides to protect water resources

Abstract

In this study, we selected and characterized different pesticide-tolerant bacteria isolated from a biomixture of a biopurification system that had received continuous applications of a pesticides mixture. The amplicon analysis of biomixture reported that the phyla Proteobacteria, Firmicutes, Bacteroidetes and Actinobacteria were predominant. Six strains grew in the presence of chlorpyrifos and iprodione. Biochemical characterization showed that all isolates were positive for esterase, acid phosphatase, among others, and they were identified as Pseudomonas, Rhodococcus and Achromobacter based on molecular and proteomic analysis. Bacterial growth decreased as both pesticide concentrations increased from 10 to 100 mg L-1 in liquid culture. The Achromobacter sp. strain C1 showed the best chlorpyrifos removal rate of 0.072-0.147 d-1 a half-life of 4.7-9.7 d and a maximum metabolite concentration of 2.10 mg L-1 at 120 h. On the other hand, Pseudomonas sp. strain C9 showed the highest iprodione removal rate of 0.100-0.193 d-1 a half-life of 4-7 d and maximum metabolite concentration of 0.95 mg L-1 at 48 h. The Achromobacter and Pseudomonas strains showed a good potential as chlorpyrifos and iprodione-degrading bacteria.

Treatment of Pesticide-Contaminated Water Using a Selected Fungal Consortium: Study in a Batch and Packed-Bed Bioreactor

“…Both fungi strains were able to remove high concentrations of ATZ, IPR, and CHL, pesticides with different chemical structures and chemical characteristics (Table 1) that confer them several degrees of toxicity and persistence in the environment. The organic biomixture used in BPS is a good source of microorganisms adapted to pesticides, as reported in other studies, including our previous results [12,13,15]. Recently, we reported that bacteria like the Achromobacter sp.…”

“…Samples were taken and treated according to the description by Briceño et al [12]. The analysis was conducted using a Merck Hitachi L-2130 pump equipped with a Rheodyne 7725 injector and a Merck Hitachi L-2455 diode array detector.…”

“…The biopurification system (BPS) for pesticide removal is based on adsorption and degradation processes occurring in an organic biomixture composed of soil, peat, and wheat straw. This technology is very efficient in pesticide removal, achieving high levels of degradation for different pesticides that are commonly applied in farms, even after repeated applications [12]. In BPS, many diverse microorganisms, including bacteria and fungi, form part of the biomixture [12,13].…”

“…This technology is very efficient in pesticide removal, achieving high levels of degradation for different pesticides that are commonly applied in farms, even after repeated applications [12]. In BPS, many diverse microorganisms, including bacteria and fungi, form part of the biomixture [12,13]. Recent studies report that microbial consortia and bacteria-single strains isolated from a BPS can efficiently remove pesticides such as CHL, iprodione (IPR), ATZ [12], 2,4-Dichlorophenoxyacetic acid, carbofuran, diazinon, and glyphosate [14], while the fungus Lecanicillium saksenae isolated from a contaminated biomixture was able to remove pendimethalin [15].…”

“…In BPS, many diverse microorganisms, including bacteria and fungi, form part of the biomixture [12,13]. Recent studies report that microbial consortia and bacteria-single strains isolated from a BPS can efficiently remove pesticides such as CHL, iprodione (IPR), ATZ [12], 2,4-Dichlorophenoxyacetic acid, carbofuran, diazinon, and glyphosate [14], while the fungus Lecanicillium saksenae isolated from a contaminated biomixture was able to remove pendimethalin [15]. Therefore, from BPS, one can obtain some adapted microorganisms that can be used as inocula to increase efficiency in the treatment of pesticides.…”