Browsing by Author "Boufercha, Oumeima"
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- Actinobacteria isolated from wastewater treatment plants located in the east-north of Algeria able to degrade pesticidesPublication . Boufercha, Oumeima; Moreira, Irina Sousa; Castro, Paula M. L.; Boudemagh, AllaoueddineThe 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.
- Bacterial strain labrys portucalensis F11 degrades the neonicotinoid insecticide thiamethoxam and removes toxicityPublication . Boufercha, Oumeima; Monforte, Ana R.; Boudemagh, Allaoueddine; Ferreira, António C.; Castro, Paula M. L.; Moreira, Irina S.
- Biodegradation and metabolic pathway of the neonicotinoid insecticide thiamethoxam by Labrys portucalensis F11Publication . Boufercha, Oumeima; Monforte, Ana R.; Boudemagh, Allaoueddine; Ferreira, António C.; Castro, Paula M. L.; Moreira, Irina S.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.
- Streptomyces sp. Strain SRH22: a potential bioremediation agent for glyphosate-contaminated agricultural soilsPublication . Rebai, Hadjer; Sholkamy, Essam Nageh; Alharbi, Reem Mohammed; Abdel-Raouf, Neveen; Boufercha, Oumeima; Castro, Paula; Boudemagh, AllaoueddineGlyphosate, also known as N-phosphonomethylglycine, is the herbicide that is widely used across the globe. As there are concerns over its potential toxicity to non-target soil species, there is a growing interest in identifying glyphosate-degrading microorganisms in soil. Biodegradation, by actinobacteria, is a very promising approach to eliminate this pesticide from contaminated environments. The present work isolated and identified actinobacteria capable of degrading glyphosate from Saharan agriculture, as well as determined how the application of this herbicide affects the abundance of actinobacteria present in soil. It was observed that the use of glyphosate led to an increased abundance of actinobacteria in the soil compared to the untreated soil. Among this population, an actinobacterial strain was isolated from glyphosate contaminated soil by the enrichment method, and was identified to possess the greatest capability to degrade glyphosate at 50 mg/L. The identification of this strain was achieved through a combination of cultural, morphological, biochemical, and molecular techniques. This included the use of 16S rDNA sequencing, leading to its successful classification as Streptomyces sp. strain SRH22. This strain was assigned the accession number OQ302556 by the National Center for Biotechnology Information (NCBI). A rapid, sensitive, and straightforward spectrophotometric technique was employed for the quantification of glyphosate. Results showed that the optimal biodegradation (90.2%) was obtained under a temperature of 30 degrees, a PH of 7.2, and an inoculum volume of 4% timed over six days. This work shows that the Streptomyces SRH22 presents good potentiality to be used as a bioremediation agent for agricultural soils in the Algerian Sahara.
- Study of the biodegradation of the insecticide thiamethoxam by streptomyces strains isolated from wastewater treatment plants in AlgeriaPublication . Boufercha, Oumeima; Moreira, Irina Sousa; Castro, Paula Maria Lima; Allaoueddine, BoudemaghThiamethoxam 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.
- Study of the biodegradation of the insecticide alpha-cypemethrin by indigenous actinobacteria isolated from activated sludgePublication . Boufercha, Oumeima; Moreira, Irina Sousa; Castro, Paula Maria Lima; Boudemagh, Allaoueddine
- Study of the biodegradation of the insecticide alpha-cypemethrin by indigenous actinobacteria isolated from activated sludgePublication . Boufercha, Oumeima; Moreira, Irina Sousa; Castro, Paula Maria Lima; Allaoueddine, BoudemaghSynthetic pyrethroids such as the insecticide alpha-cypermethrin have been widely used in agriculture to protect fruits and vegetables from various pests. Alpha-cypermethrin has beneficial effects but at the same time is toxic to aquatic life and highly carcinogenic to humans. This product is stable to hydrolysis at neutral pH, is very low soluble in water. It is therefore very likely to accumulate in aquatic ecosystems. Various methods are available to remove alpha-cypermethrin from the environment, but these methods are costly and time consuming. This study focuses on the isolation of indigenous Actinobacteria capable of degrading alpha-cypermethrin. The use of microorganisms has received considerable attention as a natural and eco- friendly method. In this study, eight Actinobacteria were isolated from the activated sludge sample using two selective isolation media: Olson and Czapeck dox modified. All these isolates were tested for their ability to degrade the target compound on solid media supplemented with 50 mg/l of alpha-cypermethrin. The results obtained indicate three Actinobacteria isolates were able to growth on the plates containing alpha-cypermethrin as the only source of carbon at a temperature of 30°C during 7 days of incubation. This is a strong indication on the ability of isolated bacteria for the degradation of the target compound. The molecular identification of these isolates allowed to assign them to the genus Streptomyces. This study showed that Actinobacteria recovered from activated sludge could be used in the bioremediation of aquatic environments contaminated by this type of pesticides.
- Study of the role of indigenous actinobacteria from activated sludge in the degradation of the fungicide fenhexamidPublication . Boufercha, Oumeima; Moreira, Irina Sousa; Castro, Paula Maria Lima; Allaoueddine, BoudemaghFenhexamid is a fungicide from hydroxyanil family with excellent activity against phyto-pathogenic fungi such as Botrytis cinerea, Monilinia spp and Scleorotinia sclerottioum. The rate of disappearance of this fungicide in natural water seems to be slow and can be accumulated in the body of aquatic organisms. Therefore, it can be an endocrine disruptor for people who consume these contaminated organisms. Because of its toxicity to non-target species, finding microorganisms with ability to degrade this fungicide is of great interest in the bioremediation of polluted sites. Actinobacteria are microorganisms with an impressive enzymatic potential and are therefore able to live and adapt to the most polluted ecosystems. In the present study, seven strains of Actinobacteria were isolated from the activated sludge of the Ibn Ziad wastewater treatment plant (City of Constantine). The screening of these strains for the degradation of fenhexamid was evaluated by growth on a minimum solid mineral medium supplemented with fenhexamid at 50 ppm, 200 ppm and 500 ppm as sole carbon source. According to the results of phenotypic and molecular analysis, the Actinobacteria isolates were assigned to three different genera: Streptomyces, Actinomadura and Micrococcus. This study showed that the Actinobacteria recovered from activated sludge of a wastewater treatment plant on Algeria, could be used in the bioremediation of aquatic environments contaminated by this type of pesticides.
- Study of the role of indigenous actinobacteria from activated sludge in the degradation of the fungicide fenhexamidPublication . Boufercha, Oumeima; Moreira, Irina Sousa; Castro, Paula Maria Lima; Allaoueddine, Boudemagh