Study of the role of indigenous actinobacteria from activated sludge in the degradation of the fungicide fenhexamid

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Biodegradation of 2,4 DCP herbicide by streptomyces collinus isolated from wastewater treatment plant in eastern Algeria

Wastewater treatment plants are the place where most pollutants are transported. 2, 4 DCP is an herbicide widely used in agriculture. This carcinogenic pollutant is very dangerous because it can reach surface waters through runoff and deep waters widely used by humans and animals. Water treatment plants are a reservoir of multiple and varied microorganisms, able to eliminate the toxic effect of many pollutants. The actinobacteria by their impressive metabolic abilities, are among the most appreciated microbial agents in the bioremediation of these hydric sites. In order to evaluate the functionality of the Ibn Ziad station in Constantine, we tested some physicochemical characteristics and the biodiversity of actinobacteria able to tolerate and degrade 2, 4 DCP. Sampling was carried out on raw wastewater, treated water and aeration tank water. The parameters studied were temperature, pH, conductivity, salinity, BOD5, DOC and suspended matters (MES). Actinobacteria were isolated on four selective media, namely AF, modified Czapeck dox, ISP4, Olson. The determination of herbicide biodegradation capacity by these bacteria was tested first on a minimum solid medium supplemented with 50 mg/L of 2, 4-DCP as a single carbon and energy source. Isolates that grew on this medium were cultured in liquid medium in the presence of 50 mg/L of the same pollutant. The degradation kinetics were monitored by HPLC. The best performing isolate was identified by phenotypic and molecular methods. The results show slightly alkaline pH, ambient temperatures. The DOC/BOD5 ratio is less than three, which indicates a slightly biodegradable effluent. While the MES concentration is around 256.7 mg/L. This station shows an important biodiversity of actinobacteria, with 25 isolates, among which 18 are able to live in the presence of 2, 4-DCP. The study of the kinetics of growth and degradation shows a good performance of an isolate, with a degradation rate of 45% after one month of incubation. The polyphasic identification of this bacterium, allows to assign it to the species Streptomyces collinus strain NBRC 12759 16S. These results show that the waters of thisstation are rich in actinobacteria able to degrade the herbicide 2, 4-DCP. These bacteria can be used in the bioremediation of water ecosystems polluted by this phytosanitary productinfo:eu-repo/semantics/publishedVersio

Biodegradation of 2,4 DCP herbicide by streptomyces collinus isolated from wastewater treatment plant in eastern Algeria

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Study of the biodegradation of the insecticide alpha-cypemethrin by indigenous actinobacteria isolated from activated sludge

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Biodegradation and metabolic pathway of the neonicotinoid insecticide thiamethoxam by Labrys portucalensis F11

Thiamethoxam (TMX) is an effective neonicotinoid insecticide. However, its widespread use is detrimental to non-targeted organisms and water systems. This study investigates the biodegradation of this insecticide by Labrys portucalensis F11. After 30 days of incubation in mineral salt medium, L. portucalensis F11 was able to remove 41%, 35% and 100% of a supplied amount of TMX (10.8 mg L−1) provided as the sole carbon and nitrogen source, the sole carbon and sulfur source and as the sole carbon source, respectively. Periodic feeding with sodium acetate as the supplementary carbon source resulted in faster degradation of TMX (10.8 mg L−1); more than 90% was removed in 3 days. The detection and identification of biodegradation intermediates was performed by UPLC-QTOF/MS/MS. The chemical structure of 12 metabolites is proposed. Nitro reduction, oxadiazine ring cleavage and dechlorination are the main degradation pathways proposed. After biodegradation, toxicity was removed as indicated using Aliivibrio fischeri and by assessing the synthesis of an inducible β-galactosidase by an E. coli mutant (Toxi-Chromo test). L. portucalensis F11 was able to degrade TMX under different conditions and could be effective in bioremediation strategies.info:eu-repo/semantics/publishedVersio

Bacterial strain labrys portucalensis F11 degrades the neonicotinoid insecticide thiamethoxam and removes toxicity

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Actinobacteria isolated from wastewater treatment plants located in the east-north of Algeria able to degrade pesticides

The pollution of water resources by pesticides poses serious problems for public health and the environment. In this study, Actinobacteria strains were isolated from three wastewater treatment plants (WWTPs) and were screened for their ability to degrade 17 pesticide compounds. Preliminary screening of 13 of the isolates of Actinobacteria allowed the selection of 12 strains with potential for the degradation of nine different pesticides as sole carbon source, including aliette, for which there are no previous reports of biodegradation. Evaluation of the bacterial growth and degradation kinetics of the pesticides 2,4-dichlorophenol (2,4-DCP) and thiamethoxam (tiam) by selected Actinobacteria strains was performed in liquid media. Strains Streptomyces sp. ML and Streptomyces sp. OV were able to degrade 45% of 2,4-DCP (50 mg/l) as the sole carbon source in 30 days and 84% of thiamethoxam (35 mg/l) in the presence of 10 mM of glucose in 18 days. The biodegradation of thiamethoxam by Actinobacteria strains was reported for the first time in this study. These strains are promising for use in bioremediation of ecosystems polluted by this type of pesticides.info:eu-repo/semantics/acceptedVersio

Study of the biodegradation of the insecticide thiamethoxam by streptomyces strains isolated from wastewater treatment plants in Algeria

Thiamethoxam is a neonicotinoid insecticide used to control a wide range of pests in a broad variety of agricultural fields. Thiamethoxam may pose some risk to the environment and the health of living organisms. The objective of this study is to isolate actinomycetes strains able to degrade thiamethoxam. In the present study, three thiamethoxam-degrading actinomycetes, were isolated from the activated sludge of Oued El Athmania wastewater treatment plant (Algeria). On the basis of morphological, physiological and biochemical characteristics, combined with phylogenetic analysis of the 16S rRNA gene, these actinomycetes were affiliated to the genus Streptomyces. Evaluation of the degradation of 35 mg/L of thiamethoxam was accomplished in liquid medium. The monitoring of the biodegradation was done by HPLC. The results show that Streptomyces sp. OV was able to degrade 84% of thiamethoxam in the presence of 10 mM glucose, while the strains Streptomyces sp. OB and Streptomyces sp. OH could degrade 78% and 69% of thiamethoxam, respectively, in the presence of 5.9 mM sodium acetate, during 18 days of incubation. Experiments were performed at 30°C, pH 7 and under agitation of 130 rpm. The isolated Streptomyces strains are potential candidates to be used for the developed of biotechnological solutions to eliminate this insecticide from contaminated sites.info:eu-repo/semantics/publishedVersio