Browsing by Author "Moreira, Irina Sousa"
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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.
- Biodegradation of 2,4 DCP herbicide by streptomyces collinus isolated from wastewater treatment plant in eastern AlgeriaPublication . Oumeima, Boufercha; Allaoueddine, Boudemagh; Moreira, Irina Sousa; Castro, Paula Maria LimaWastewater 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 product
- Biodegradation of 2,4 DCP herbicide by streptomyces collinus isolated from wastewater treatment plant in eastern AlgeriaPublication . Oumeima, Boufercha; Allaoueddine, Boudemagh; Moreira, Irina Sousa; Castro, Paula Maria Lima
- Isolation and identification of actinomycetes degrading the fungicid Allial from the activated sludge of the wastewater treatment plant Ibn Ziad (Constantine city)Publication . Oumeima, Boufercha; Moreira, Irina Sousa; Castro, Paula Maria Lima; Allaoueddine, BoudemaghThe old methods of agriculture were based on the use of intensive manual labor. The twentieth century saw the birth of a revolution in agricultural practices, which relied mainly on plant protection techniques. These new perspectives have paved the way for an agriculture dominated by pesticides. The use of these molecules has improved yields and crop diversity to meet the nutritional needs of the growing world population. However, in recent years, other health and environmental problems have arisen due to uncontrolled overuse. Allial (fosetyl aluminum) is a systemic fungicide of the phosphonate class. It is not very persistent in soils and water and is recalcitrant to hydrolysis at environmental pH. This fungicide is also very soluble in water and can therefore reach surface waters by leaching from agricultural soils. Photolysis of this xenobiotic is not possible. In order to remove this fungicide from wastewater, biological treatment methods are necessary. Activated sludge microorganisms can play an important role in its biodegradation. In this study, were isolated actinomycetes from activated sludge of the wastewater treatment plant of Ibn Ziad. These bacteria, known by their extraordinary metabolic diversities, were tested for their aptitudes to degrade this toxic pesticide. Minimum salt medium supplemented with different concentrations up to 200 mg/L of fosetyl aluminum as the only carbon source. The cultures were incubated during 5 days at a temperature of 30° C. According to the results obtained, five isolates of actinobacteria showed a significant potential for the biodegradation of this fungicide. The identification of these isolates by analysis of the 16S rDNA gene allowed to assign them to the Streptomyces genus.
- 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