Prof. Dr Wafaa M. Abd El-Rahim (original) (raw)
Papers by Prof. Dr Wafaa M. Abd El-Rahim
ABSTRACT The textile industry is among the major industries in Egypt. Dyes pollution is a serious... more ABSTRACT The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to human health as a result of their toxic potential. The aim of the current report was to isolate potential native Egyptian fungal strains for bioremediation of dyes pollution. Nine fungal strains were collected from four of the major textile factory-dumping sites in Egypt. They were tested for their ability to remove commonly used textile dye (Dis-azo dye) as sole carbon and energy source. Results revealed that these strains are capable of removing Dis-azo Dye. Moreover, maximum dye-removing efficiency was observed following 24 to 48 hours incubation. We amplified and sequenced the nuclear internal transcribed spacer (ITS) for molecular identification. The high ratio of synonymous to nonsynonymous changes indicates that the ITS region of these strains is evolving under purifying selection.
Journal of Applied Toxicology, Aug 1, 2008
Journal of Applied Toxicology (28: 484-490) a mistake was found in the injection method described... more Journal of Applied Toxicology (28: 484-490) a mistake was found in the injection method described in the Materials and Methods. The 9 th sentence under Experimental Design, column 2, page 484 should read: All animals received daily oral gavage injection for a period of 2 weeks or 8 weeks.
Plants, Jul 16, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Egyptian Journal of Chemistry, 2019
F LAX retting is a treatment process employed to dissolve or rot away much of the cellular tissue... more F LAX retting is a treatment process employed to dissolve or rot away much of the cellular tissues and pectins surrounding bast/fiber bundles thus facilitating separation of the fiber from the stem. The microbial retting is one of the most environmentally friendly process. The rich source of microbes contributing to flax retting is the retting water in commercial retting plants. The main objective of this work is to accelerate the flax retting using selected bacterial strains contributing to retting and degumming of flax in order to avoid chemicals causing environmental pollution. In this work, reuse of retting water for acceleration of flax retting was tested. The results show that, the reuse of retted water in new cycle of flax retting has accelerated the retting completion by 8.3-25% depending on the ratio of reused retted water in the retting liquor. Therefore, samples of flax straw retted water and soils from flax fields located in Nile Valley and Delta soils were collected for isolation of flax retting bacteria predominant in the retting effluents. Identification of the isolates was done using morphological, physiological and biochemical tests. Ten bacterial isolates were identified as Lactococcus cremoris, Chryseobacterium culicis, Serratia marcescens, Capnocytophage granulose, Micrococcus luteus, Enterobacter homraechei, Klebsiella oxytoca, Paenibacillus polymyxa, Proteus mirabilis and Bacillus humi. Three efficient strains in pectinase production necessary for flax retting were selected to test their role in enhancing the retting process. These strains are Bacillus humi, Chryseobacterium culicis and Micrococcus luteus which showed specific pectinase activity 37.17, 33.53 and 28 Umg 1 respectively. The effect of these strains on retting duration and fiber quality were studied. The combinations of the three strains were tested in the lab scale cylindrical experimental bioreactor and each of the combinations was compared with the classical retting process of the industrial units. The combined treatment using strains: Chryseobacterium culicis, Micrococcus luteus and Bacillus humi resulted in the reduction of the retting duration by 30%, whereas, the mixed inocula containing Chryseobacterium culicis and Micrococcusluteus reduced the retting time by 25%. The mixture of Micrococcus luteus and Bacillus humi reduced the retting duration by 20%. The determination of weight loss, tensile strength, whiteness and yellowness of the fibers after microbial retting was monitored. These results indicate that the obtained specific bacterial strains enhanced the retting process.
Catrina: The International Journal Of Environmental Sciences
Hundred fifty bacterial isolates were obtained by enrichment culture from 12 samples collected fr... more Hundred fifty bacterial isolates were obtained by enrichment culture from 12 samples collected from soil contaminated with dye effluents and effluent treatment plants of textile and dyeing industry at New Borg El-Arab, Cairo, Kafr El-Dawar, and El-Mehalla El-Kubra regions. The isolation of the microbial consortium was conducted on mineral salts medium (MSM) supplemented with three dyes. The microbial consortium was able to decolorize dyes, as evident by clearing the three azo dyes solutions under anoxic and anaerobic conditions. The isolates were checked for their ability to decolorize direct violet and reactive red dyes. The efficiency of the bacterial isolates in dye removal was investigated under aerobic and anaerobic conditions. The study revealed that no decolorization has taken place by isolates under aerobic conditions. The results revealed that the percentage of decolorization by the isolates reached 98.52 and 97.95 % of the original color of direct violet and reactive red dyes after 9 and 15 days, respectively, under anaerobic conditions. Twenty five isolates were selected as representative isolates based on the morphological and biochemical analyses. Two isolates are long rod, 6 isolates are short rods, and seventeen isolates belong to family enterobacteraece. The characterization of bacteria showed that the isolates belong to Bacillus and Pseudomonas sp. The degradation of the dyes is usually judged by the formation of aromatic amines. Most of the isolates under anoxic conditions were found to produce aromatic amines. This suggests the degradation of the dyes by the isolated bacteria.
Catrina The International journal Of Environmental Sciences
A series of batch and bioreactors experiments were carried out for absorption of dis-azo dyes pre... more A series of batch and bioreactors experiments were carried out for absorption of dis-azo dyes present in textile mill effluents under different aeration conditions. One fungal strain with five rates of air was used to absorb direct brown dye. Five liters bioreactors were applied to study the removal performance. The experimental results are compared for various operating conditions. The effects of airflow rate (1/8, ¼, ½, 1, 2 v/v min) inlet on the dye removing were assessed. It was found that the rate of aeration of ½ v/v min induced increase in dye removal percentages (72%) and fungal biomass (9.2 g); at the rate of aeration of 2 v/v min, high dye removal percentage (77%) was recorded with a decrease in biomass dry weight at the end of the incubation time. The results also indicated that the biomass dry weight obtained at three flow rates of aeration was more or less similar until the end of the growth stage (after incubation for three days). The results obtained indicate that using low rate of aeration (1/8, ¼, ½ v/v min) was better for dye biosorption than high rate (1, 2 v/v min), and therefore it is recommended for dis-azo dye removing.
Aswan University Journal of Environmental Studies
Egyptian Journal of Chemistry, 2022
Journal of King Abdulaziz University-Meteorology, Environment and Arid Land Agriculture Sciences, 2011
Egyptian Journal of Chemistry, 2019
T HE hexavalent chromium salts are widely used in many industries worldwide including leather tan... more T HE hexavalent chromium salts are widely used in many industries worldwide including leather tanning industry. The residues of these salts are discharged into the environment causing serious health hazardous to human, animals and plants. The chemical remediation of the Cr VI residues is costly and adds more pollutants to the environment. Therefore, the bioremediation of toxic hexavalent chromium residues is the aim of this study. For this purpose, the soil and wastewater samples from the heavily contaminated sites near tanneries were used for the isolation of Cr VI resistant bacteria. A total of 33 bacterial isolates was obtained from samples grown on LB medium amended with 50 mgL-1 potassium di chromate (Cr VI). These isolates were screened for their growth in the medium amended with Cr VI concentrations ranging between 100 and 200 mgL-1. Seven isolates showed tolerance to the highest concentration. These isolates were subjected to analysis of 16S rDNA genes followed by RFLP of the PCR product. The most promising isolate (No.3) that withstood the highest Cr VI concentration was further subjected to 16S rDNA gene nucleotide sequence. This isolate turned to be Microbacterim spp. with 98% similarity to the standard strain in the gene bank. The sequence was deposited in NCBI data bank under accession number mk878392. The efficiency of this indigenous strain of bacteria in removal of Cr VI from aquas solution showed that it was capable to remove 30% of Cr VI within first 20 hours then exponential increase took place after additional 20 hours. The total removal of Cr VI reached 97.2% after 96 hours of incubation. The immobilization of the strain on either alginate or chitosan accelerated the removal of Cr VI that reached 90% removal in 18 hours. This strain seems very promising as potential bioremediation agent for hexavalent chromium residues.
The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to ... more The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to human health as a result of their toxic potential. The aim of the current report was to isolate potential native Egyptian fungal strains for bioremediation of dyes pollution. Nine fungal strains were collected from four of the major textile factory-dumping sites in Egypt. They were tested for their ability to remove commonly used textile dye (Dis-azo dye) as sole carbon and energy source. Results revealed that these strains are capable of removing Dis-azo Dye. Moreover, maximum dyeremoving efficiency was observed following 24 to 48 hours incubation. We amplified and sequenced the nuclear internal transcribed spacer (ITS) for molecular identification. The high ratio of synonymous to nonsynonymous changes indicates that the ITS region of these strains is evolving under purifying selection.
Experiments were done to study the bioremoval / biosorption of dis-azo dye by Aspergillus niger s... more Experiments were done to study the bioremoval / biosorption of dis-azo dye by Aspergillus niger strain 20 in two concentrations using 5 liter bioreactor at five aeration rates. The experimental results are compared for various operating conditions. The dye used was direct brown and the inlet air flow rate was: 1/8, , , 1, 2 v/v/min. The aeration rate of v/v/min yielded 9.2 g fungal biomass and removed 72 % of the dye. Increasing of the aeration rate to 2 v/v/min increased the removal to 77%, whereas the biomass was decreased markedly at the end of the incubation time. The results also indicate that the fungal biomass obtained at the three other air flow rates was more or less the same after 3 days of incubation. The obtained results indicate that air flow rates 1/8, and v/v/min gave better dye bioremoval as compared with the high aeration rate (1, 2 v/v/min) and can be recommended for dis-azo dye bioremediation. Isotherm experiments were conducted to determine the sorbents-desorptio...
The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to ... more The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to human health as a result of their toxic potential. The aim of the current report was to isolate potential native Egyptian fungal strains for bioremediation of dyes pollution. Nine fungal strains were collected from four of the major textile factory-dumping sites in Egypt. They were tested for their ability to remove commonly used textile dye (Dis-azo dye) as sole carbon and energy source. Results revealed that these strains are capable of removing Dis-azo Dye. Moreover, maximum dye-removing efficiency was observed following 24 to 48 hours incubation. We amplified and sequenced the nuclear internal transcribed spacer (ITS) for molecular identification. The high ratio of synonymous to nonsynonymous changes indicates that the ITS region of these strains is evolving under purifying selection.
The textile dye residues represent a growing threat to the surrounding environment of this vital ... more The textile dye residues represent a growing threat to the surrounding environment of this vital industry. Therefore, the appropriate technology for the removal of dye residues from industrial effluents is an important task. One of these technologies is based on the bioremediation that depends on using certain microorganisms to remove these toxic wastes. It is well known that the microbial agents perform all biological transformations through immense enzymatic tools existing within the intact microbial cells. The use of the specific enzymes required for breakdown of certain industrial wastes can reduce the time of residues removal and consequently the cost of the process. In this study the production of two fungal enzymes namely laccases and peroxidases were assessed. To study these enzymes fifteen fungal strains were first screened for their growth on mineral salt medium supplemented with 0.5g/L of green azo dyes as sole source of carbon. The strains could grow on the above mention...
Research journal of pharmaceutical, biological and chemical sciences, 2014
Azo dyes constitute the largest class of synthetic dyes and represent the major chemical in texti... more Azo dyes constitute the largest class of synthetic dyes and represent the major chemical in textile industry wastewater. The remediation of textile industry wastewater before reaching the agricultural environment is of significance for the safety of the surrounding environment. However, the recalcitrant nature of these chemicals requires special technologies to remove and/or reduce the risks associated with their discharge. The bioremediation of these toxic synthetic dyes is among the approaches for remediation of textile industry wastewater. This study focuses on the isolation, screening and azo dye removal by bacteria isolated from dumping site of textile wastewater. Fourteen isolates were tested in this study. One of them was the most efficient in decolourization of RB dye. This isolate was identified by 16s DNA sequences to Pseudomonas aeruginosa strain OS4 (NCBI accession number: KC762943). Bioremediation of azo dyes was found to occur efficiently under two sequential phases; s...
Now a day it is very important to remove industrial pollutants with minimum cost. The present wor... more Now a day it is very important to remove industrial pollutants with minimum cost. The present work focused on the assessment of extracellular laccases produced by different fugal strains and its potential for Direct Green (DG) bio-removal from textile effluent water, which can be used as a resource of non-traditional water. Ten fungal strains from polluted sites were screened to test their capability of DG bioremoval to clean up waste water containing-dye. Fungal dye removal capacity was assessed by measuring the residual of DG dye in supernatant using spectrophotometer, over production of fungal biomass and reduction of COD values after 28h of incubation. Results showed that the fungal isolates could remove the simulated effluent containing-DG dye and they reduced the COD values indicating on bio-removal of dye from the growth media. Strain FRD 11 was the most effective strain which removed about 85% of (300 mgl -1 ) dye in 28h. Molecular characterization of fungal isolates was don...
Biodegradation of atrazine in Nile Delta agricultural soils previously treated with atrazine unde... more Biodegradation of atrazine in Nile Delta agricultural soils previously treated with atrazine under a maize cropping rotation system was investigated under controlled laboratory conditions. Two techniques were used to follow atrazine biodegradation kinetics: i) incubated soil samples and ii) soil suspension (slurry technique). An enrichment technique and atrazine agar indicator plates were used to isolate atrazine-degrading bacteria. Both tested soils showed high and similar ability to degrade atrazine, in which atrazine dissipated completely without detection of any metabolites in soil suspensions at 7 and 3 days after the first and second enrichment, respectively. Atrazine degradation rate constants (k) were significantly increased by repeated enrichment: they increased from 0.4 and 0.5 d after the first enrichment to 1.3 and 1.2 d after the second enrichment for Soil I and II, respectively. Also, atrazine biodegradation kinetics was strongly affected by atrazine application number...
Research journal of pharmaceutical, biological and chemical sciences, 2016
A series of batch and bioreactors experiments were carried out for absorption of dis-azo dyes pre... more A series of batch and bioreactors experiments were carried out for absorption of dis-azo dyes present in textile mill effluents under different aeration conditions. One fungal strain with five rates of air was used to absorb direct brown dye. Five liters bioreactors were applied to study the removal performance. The experimental results are compared for various operating conditions. The effects of airflow rate (1/8, ¼, ½, 1, 2 v/v min) inlet on the dye removing were assessed. It was found that the rate of aeration of ½ v/v min induced increase in dye removal percentages (72%) and fungal biomass (9.2 g); at the rate of aeration of 2 v/v min, high dye removal percentage (77%) was recorded with a decrease in biomass dry weight at the end of the incubation time. The results also indicated that the biomass dry weight obtained at three flow rates of aeration was more or less similar until the end of the growth stage (after incubation for three days). The results obtained indicate that usi...
ABSTRACT The textile industry is among the major industries in Egypt. Dyes pollution is a serious... more ABSTRACT The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to human health as a result of their toxic potential. The aim of the current report was to isolate potential native Egyptian fungal strains for bioremediation of dyes pollution. Nine fungal strains were collected from four of the major textile factory-dumping sites in Egypt. They were tested for their ability to remove commonly used textile dye (Dis-azo dye) as sole carbon and energy source. Results revealed that these strains are capable of removing Dis-azo Dye. Moreover, maximum dye-removing efficiency was observed following 24 to 48 hours incubation. We amplified and sequenced the nuclear internal transcribed spacer (ITS) for molecular identification. The high ratio of synonymous to nonsynonymous changes indicates that the ITS region of these strains is evolving under purifying selection.
Journal of Applied Toxicology, Aug 1, 2008
Journal of Applied Toxicology (28: 484-490) a mistake was found in the injection method described... more Journal of Applied Toxicology (28: 484-490) a mistake was found in the injection method described in the Materials and Methods. The 9 th sentence under Experimental Design, column 2, page 484 should read: All animals received daily oral gavage injection for a period of 2 weeks or 8 weeks.
Plants, Jul 16, 2023
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Egyptian Journal of Chemistry, 2019
F LAX retting is a treatment process employed to dissolve or rot away much of the cellular tissue... more F LAX retting is a treatment process employed to dissolve or rot away much of the cellular tissues and pectins surrounding bast/fiber bundles thus facilitating separation of the fiber from the stem. The microbial retting is one of the most environmentally friendly process. The rich source of microbes contributing to flax retting is the retting water in commercial retting plants. The main objective of this work is to accelerate the flax retting using selected bacterial strains contributing to retting and degumming of flax in order to avoid chemicals causing environmental pollution. In this work, reuse of retting water for acceleration of flax retting was tested. The results show that, the reuse of retted water in new cycle of flax retting has accelerated the retting completion by 8.3-25% depending on the ratio of reused retted water in the retting liquor. Therefore, samples of flax straw retted water and soils from flax fields located in Nile Valley and Delta soils were collected for isolation of flax retting bacteria predominant in the retting effluents. Identification of the isolates was done using morphological, physiological and biochemical tests. Ten bacterial isolates were identified as Lactococcus cremoris, Chryseobacterium culicis, Serratia marcescens, Capnocytophage granulose, Micrococcus luteus, Enterobacter homraechei, Klebsiella oxytoca, Paenibacillus polymyxa, Proteus mirabilis and Bacillus humi. Three efficient strains in pectinase production necessary for flax retting were selected to test their role in enhancing the retting process. These strains are Bacillus humi, Chryseobacterium culicis and Micrococcus luteus which showed specific pectinase activity 37.17, 33.53 and 28 Umg 1 respectively. The effect of these strains on retting duration and fiber quality were studied. The combinations of the three strains were tested in the lab scale cylindrical experimental bioreactor and each of the combinations was compared with the classical retting process of the industrial units. The combined treatment using strains: Chryseobacterium culicis, Micrococcus luteus and Bacillus humi resulted in the reduction of the retting duration by 30%, whereas, the mixed inocula containing Chryseobacterium culicis and Micrococcusluteus reduced the retting time by 25%. The mixture of Micrococcus luteus and Bacillus humi reduced the retting duration by 20%. The determination of weight loss, tensile strength, whiteness and yellowness of the fibers after microbial retting was monitored. These results indicate that the obtained specific bacterial strains enhanced the retting process.
Catrina: The International Journal Of Environmental Sciences
Hundred fifty bacterial isolates were obtained by enrichment culture from 12 samples collected fr... more Hundred fifty bacterial isolates were obtained by enrichment culture from 12 samples collected from soil contaminated with dye effluents and effluent treatment plants of textile and dyeing industry at New Borg El-Arab, Cairo, Kafr El-Dawar, and El-Mehalla El-Kubra regions. The isolation of the microbial consortium was conducted on mineral salts medium (MSM) supplemented with three dyes. The microbial consortium was able to decolorize dyes, as evident by clearing the three azo dyes solutions under anoxic and anaerobic conditions. The isolates were checked for their ability to decolorize direct violet and reactive red dyes. The efficiency of the bacterial isolates in dye removal was investigated under aerobic and anaerobic conditions. The study revealed that no decolorization has taken place by isolates under aerobic conditions. The results revealed that the percentage of decolorization by the isolates reached 98.52 and 97.95 % of the original color of direct violet and reactive red dyes after 9 and 15 days, respectively, under anaerobic conditions. Twenty five isolates were selected as representative isolates based on the morphological and biochemical analyses. Two isolates are long rod, 6 isolates are short rods, and seventeen isolates belong to family enterobacteraece. The characterization of bacteria showed that the isolates belong to Bacillus and Pseudomonas sp. The degradation of the dyes is usually judged by the formation of aromatic amines. Most of the isolates under anoxic conditions were found to produce aromatic amines. This suggests the degradation of the dyes by the isolated bacteria.
Catrina The International journal Of Environmental Sciences
A series of batch and bioreactors experiments were carried out for absorption of dis-azo dyes pre... more A series of batch and bioreactors experiments were carried out for absorption of dis-azo dyes present in textile mill effluents under different aeration conditions. One fungal strain with five rates of air was used to absorb direct brown dye. Five liters bioreactors were applied to study the removal performance. The experimental results are compared for various operating conditions. The effects of airflow rate (1/8, ¼, ½, 1, 2 v/v min) inlet on the dye removing were assessed. It was found that the rate of aeration of ½ v/v min induced increase in dye removal percentages (72%) and fungal biomass (9.2 g); at the rate of aeration of 2 v/v min, high dye removal percentage (77%) was recorded with a decrease in biomass dry weight at the end of the incubation time. The results also indicated that the biomass dry weight obtained at three flow rates of aeration was more or less similar until the end of the growth stage (after incubation for three days). The results obtained indicate that using low rate of aeration (1/8, ¼, ½ v/v min) was better for dye biosorption than high rate (1, 2 v/v min), and therefore it is recommended for dis-azo dye removing.
Aswan University Journal of Environmental Studies
Egyptian Journal of Chemistry, 2022
Journal of King Abdulaziz University-Meteorology, Environment and Arid Land Agriculture Sciences, 2011
Egyptian Journal of Chemistry, 2019
T HE hexavalent chromium salts are widely used in many industries worldwide including leather tan... more T HE hexavalent chromium salts are widely used in many industries worldwide including leather tanning industry. The residues of these salts are discharged into the environment causing serious health hazardous to human, animals and plants. The chemical remediation of the Cr VI residues is costly and adds more pollutants to the environment. Therefore, the bioremediation of toxic hexavalent chromium residues is the aim of this study. For this purpose, the soil and wastewater samples from the heavily contaminated sites near tanneries were used for the isolation of Cr VI resistant bacteria. A total of 33 bacterial isolates was obtained from samples grown on LB medium amended with 50 mgL-1 potassium di chromate (Cr VI). These isolates were screened for their growth in the medium amended with Cr VI concentrations ranging between 100 and 200 mgL-1. Seven isolates showed tolerance to the highest concentration. These isolates were subjected to analysis of 16S rDNA genes followed by RFLP of the PCR product. The most promising isolate (No.3) that withstood the highest Cr VI concentration was further subjected to 16S rDNA gene nucleotide sequence. This isolate turned to be Microbacterim spp. with 98% similarity to the standard strain in the gene bank. The sequence was deposited in NCBI data bank under accession number mk878392. The efficiency of this indigenous strain of bacteria in removal of Cr VI from aquas solution showed that it was capable to remove 30% of Cr VI within first 20 hours then exponential increase took place after additional 20 hours. The total removal of Cr VI reached 97.2% after 96 hours of incubation. The immobilization of the strain on either alginate or chitosan accelerated the removal of Cr VI that reached 90% removal in 18 hours. This strain seems very promising as potential bioremediation agent for hexavalent chromium residues.
The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to ... more The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to human health as a result of their toxic potential. The aim of the current report was to isolate potential native Egyptian fungal strains for bioremediation of dyes pollution. Nine fungal strains were collected from four of the major textile factory-dumping sites in Egypt. They were tested for their ability to remove commonly used textile dye (Dis-azo dye) as sole carbon and energy source. Results revealed that these strains are capable of removing Dis-azo Dye. Moreover, maximum dyeremoving efficiency was observed following 24 to 48 hours incubation. We amplified and sequenced the nuclear internal transcribed spacer (ITS) for molecular identification. The high ratio of synonymous to nonsynonymous changes indicates that the ITS region of these strains is evolving under purifying selection.
Experiments were done to study the bioremoval / biosorption of dis-azo dye by Aspergillus niger s... more Experiments were done to study the bioremoval / biosorption of dis-azo dye by Aspergillus niger strain 20 in two concentrations using 5 liter bioreactor at five aeration rates. The experimental results are compared for various operating conditions. The dye used was direct brown and the inlet air flow rate was: 1/8, , , 1, 2 v/v/min. The aeration rate of v/v/min yielded 9.2 g fungal biomass and removed 72 % of the dye. Increasing of the aeration rate to 2 v/v/min increased the removal to 77%, whereas the biomass was decreased markedly at the end of the incubation time. The results also indicate that the fungal biomass obtained at the three other air flow rates was more or less the same after 3 days of incubation. The obtained results indicate that air flow rates 1/8, and v/v/min gave better dye bioremoval as compared with the high aeration rate (1, 2 v/v/min) and can be recommended for dis-azo dye bioremediation. Isotherm experiments were conducted to determine the sorbents-desorptio...
The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to ... more The textile industry is among the major industries in Egypt. Dyes pollution is a serious risk to human health as a result of their toxic potential. The aim of the current report was to isolate potential native Egyptian fungal strains for bioremediation of dyes pollution. Nine fungal strains were collected from four of the major textile factory-dumping sites in Egypt. They were tested for their ability to remove commonly used textile dye (Dis-azo dye) as sole carbon and energy source. Results revealed that these strains are capable of removing Dis-azo Dye. Moreover, maximum dye-removing efficiency was observed following 24 to 48 hours incubation. We amplified and sequenced the nuclear internal transcribed spacer (ITS) for molecular identification. The high ratio of synonymous to nonsynonymous changes indicates that the ITS region of these strains is evolving under purifying selection.
The textile dye residues represent a growing threat to the surrounding environment of this vital ... more The textile dye residues represent a growing threat to the surrounding environment of this vital industry. Therefore, the appropriate technology for the removal of dye residues from industrial effluents is an important task. One of these technologies is based on the bioremediation that depends on using certain microorganisms to remove these toxic wastes. It is well known that the microbial agents perform all biological transformations through immense enzymatic tools existing within the intact microbial cells. The use of the specific enzymes required for breakdown of certain industrial wastes can reduce the time of residues removal and consequently the cost of the process. In this study the production of two fungal enzymes namely laccases and peroxidases were assessed. To study these enzymes fifteen fungal strains were first screened for their growth on mineral salt medium supplemented with 0.5g/L of green azo dyes as sole source of carbon. The strains could grow on the above mention...
Research journal of pharmaceutical, biological and chemical sciences, 2014
Azo dyes constitute the largest class of synthetic dyes and represent the major chemical in texti... more Azo dyes constitute the largest class of synthetic dyes and represent the major chemical in textile industry wastewater. The remediation of textile industry wastewater before reaching the agricultural environment is of significance for the safety of the surrounding environment. However, the recalcitrant nature of these chemicals requires special technologies to remove and/or reduce the risks associated with their discharge. The bioremediation of these toxic synthetic dyes is among the approaches for remediation of textile industry wastewater. This study focuses on the isolation, screening and azo dye removal by bacteria isolated from dumping site of textile wastewater. Fourteen isolates were tested in this study. One of them was the most efficient in decolourization of RB dye. This isolate was identified by 16s DNA sequences to Pseudomonas aeruginosa strain OS4 (NCBI accession number: KC762943). Bioremediation of azo dyes was found to occur efficiently under two sequential phases; s...
Now a day it is very important to remove industrial pollutants with minimum cost. The present wor... more Now a day it is very important to remove industrial pollutants with minimum cost. The present work focused on the assessment of extracellular laccases produced by different fugal strains and its potential for Direct Green (DG) bio-removal from textile effluent water, which can be used as a resource of non-traditional water. Ten fungal strains from polluted sites were screened to test their capability of DG bioremoval to clean up waste water containing-dye. Fungal dye removal capacity was assessed by measuring the residual of DG dye in supernatant using spectrophotometer, over production of fungal biomass and reduction of COD values after 28h of incubation. Results showed that the fungal isolates could remove the simulated effluent containing-DG dye and they reduced the COD values indicating on bio-removal of dye from the growth media. Strain FRD 11 was the most effective strain which removed about 85% of (300 mgl -1 ) dye in 28h. Molecular characterization of fungal isolates was don...
Biodegradation of atrazine in Nile Delta agricultural soils previously treated with atrazine unde... more Biodegradation of atrazine in Nile Delta agricultural soils previously treated with atrazine under a maize cropping rotation system was investigated under controlled laboratory conditions. Two techniques were used to follow atrazine biodegradation kinetics: i) incubated soil samples and ii) soil suspension (slurry technique). An enrichment technique and atrazine agar indicator plates were used to isolate atrazine-degrading bacteria. Both tested soils showed high and similar ability to degrade atrazine, in which atrazine dissipated completely without detection of any metabolites in soil suspensions at 7 and 3 days after the first and second enrichment, respectively. Atrazine degradation rate constants (k) were significantly increased by repeated enrichment: they increased from 0.4 and 0.5 d after the first enrichment to 1.3 and 1.2 d after the second enrichment for Soil I and II, respectively. Also, atrazine biodegradation kinetics was strongly affected by atrazine application number...
Research journal of pharmaceutical, biological and chemical sciences, 2016
A series of batch and bioreactors experiments were carried out for absorption of dis-azo dyes pre... more A series of batch and bioreactors experiments were carried out for absorption of dis-azo dyes present in textile mill effluents under different aeration conditions. One fungal strain with five rates of air was used to absorb direct brown dye. Five liters bioreactors were applied to study the removal performance. The experimental results are compared for various operating conditions. The effects of airflow rate (1/8, ¼, ½, 1, 2 v/v min) inlet on the dye removing were assessed. It was found that the rate of aeration of ½ v/v min induced increase in dye removal percentages (72%) and fungal biomass (9.2 g); at the rate of aeration of 2 v/v min, high dye removal percentage (77%) was recorded with a decrease in biomass dry weight at the end of the incubation time. The results also indicated that the biomass dry weight obtained at three flow rates of aeration was more or less similar until the end of the growth stage (after incubation for three days). The results obtained indicate that usi...