Abstract Waste-to-energy is a promising approach to tackle the energy shortage and reduce the env... more Abstract Waste-to-energy is a promising approach to tackle the energy shortage and reduce the environmental pollution. The present study aimed to evaluate the technical and economic feasibility of microwave vacuum co-pyrolysis of seaweeds and low-density polyethylene (LDPE). Although the three studied seaweeds namely; Ulva intestinalis, Sargassum polycystum, and Hypnea valentiae showed similar thermal weight loss profile, U. intestinalis showed the highest biomass and bio-oil yields which resulted in superior bio-oil areal productivity of 30.1 g m−2. Therefore, it was selected for co-pyrolysis with LDPE at different blend ratios. Compared to individual pyrolysis of U. intestinalis, the increase inLDPE ratio enhanced the crude bio-oil production with simultaneous reduction in bio-char yield. The experimental bio-oil yields from co-pyrolysis showed higher values than the corresponding theoretical values, confirming a synergistic effect between the two feedstocks. The bio-oil produced from co-pyrolysis at 75% LDPE blend ratio showed better characteristics compared to the individual pyrolysis. Van Krevelen plot suggested that LDPE produces hydrogen radicals during co-pyrolysis reactions, which increased the H/C ratio and reduced the O/C ratio. GC/MS analysis confirmed that the increase in LDPE stimulates hydrocarbons proportion up to 51.2% at 75% blend ratio with significant reduction in N-containing compounds, carboxylic acids, furans, aldehydes/ketones, saccharides, and phenols. The economic feasibility analysis at a feedstock feeding rate of 11.4 ton h−1 using Aspen Plus showed estimated net profit of 23.17 million US$ for a 20-years life time plant. The present study provides a potential approach for sustainable energy recovery from waste plastic/seaweeds blend using microwave vacuum co-pyrolysis.
Growth and some metabolic activities of two cyanobacterial species (Anabaena subcylindrica and No... more Growth and some metabolic activities of two cyanobacterial species (Anabaena subcylindrica and Nostoc Linckia) grown under salinity stress with and without exogeneously added calcium chloride were monitored. Salinity treatment (0.3M NaCl) induced pronounced reduction in growth, pigment fractions, carbohydrates, O 2-evolution, respiration, lipids content and increase in the measured elements content (Na + , K + , Mg ++ , Fe +++ and Ca ++). Presence of Ca 2+ (0.03 or 0.05 M CaCl 2) caused significant recovery of the different measured growth parameters and metabolic activities. The most important changes induced by salinity treatment are:1-Reduction in the polysaccharides content of both organisms accompanied with an increase in the soluble sugars, which proposed that the possible inhibitory effect of salinity associated with osmotic regulation. This effect could be ameliorated by addition of calcium ions. 2-The integrity of the plasma membranes impaired by salinity. Presence of calcium protects the membranes against the injury induced by salinity.
In the present study, fifteen species of the dominant marine algae were collected during summer 2... more In the present study, fifteen species of the dominant marine algae were collected during summer 2013 from four selected sites on Red sea coast, Jeddah, Saudi Arabia. The collected species belonged to Chlorophyta, Phaeophyta and Rhodophyta. Crude algal extracts were prepared by successive extractions using different solvents (acetone, ethanol, diethyl ether, ethyl acetate, methanol and petroleum ether). The crude algal extracts were examined for their antifungal efficacy against Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Candida albicans and Candida tropicalis using agar well diffusion method. The algal extracts evoked different patterns of antifungal activities. Results reveal that acetone was the best solvent suited for extraction of bioactive compounds from tested seaweeds with inhibition activity (19.3%) followed by ethyl acetate (17.1%), ethanol (16.4%), petroleum ether (15.9%), diethyl ether (15.85%), and finally methanol (15.4%). Chlorophyta exhibited the highest antimycotic effect followed by Rhodophyta and Phaeophyta. In Chlorophyta, the extracts of Ulva intestinalis were the most potent followed by U. lactuca, C. racemosa, U. linza and U. reticulate. Acanthophora spicifera showed the highest activity in Rhodophyta, followed by J. rubens, D. simplex, L. obtusa, G. gracilis, G. vermicuphylla and G. multipartita. Whereas, T. triquetra was the most effective species in Phaeophyta followed by P. pavonica and D. dichotoma. The minimal inhibitory concentrations (MICs) of the most potent algal extracts were in the range of 0.5 to 4 mg/ml. The results confirmed the antimycotic potentiality of seaweed extracts.
The unicellular green alga Monoraphidium minutum and the diatom Nitzschia perminuta were cultured... more The unicellular green alga Monoraphidium minutum and the diatom Nitzschia perminuta were cultured under different concentrations of Co2+. Growth and pigment content were slightly increased at low concentrations and inhibited by high Co2+ concentrations. The results concerning the effect of different concentrations of Co2+ on photosynthetic O2 evolution showed a reduction in the amount of O2 evolved by each alga in response to increasing Co2+ concentrations. However, an increase in O2 evolution for both M. minutum and N. perminuta was observed at relatively low Co2+ concentrations. Photosynthetic electron transport in M. minutum was more sensitive to Co2+ toxicity than in N. perminuta. On the other hand, the effect of the heavy metal on respiration showed that higher Co2+ concentrations were inhibitory to O2 uptake by the two algal species. Low Co2+ concentrations stimulated O2 uptake by M. minutum throughout the experimental period. However, in N. perminuta, different concentrations...
The influence of Cu 2+ toxicity on dry mass, chl.a, carotenoids, protein content, Cu 2+ uptake, a... more The influence of Cu 2+ toxicity on dry mass, chl.a, carotenoids, protein content, Cu 2+ uptake, activities of some enzymes of nitrogen assimilation and alkaline phosphatase in the diazotrophic cyanobacterium Anabaena variabilis was evaluated. Lower Cu 2+ concentrations stimulated the dry weight, chl.a, and protein content, whereas, higher concentrations were inhibitory. In contrast, a prominent increase in the carotenoids content was detected in response to all Cu 2+ treatments. A. variabilis showed high uptake capacity of Cu 2+. The accumulation capacity is directly proportional to the external Cu 2+ concentrations. A stimulation in the activities of glutamine synthetase (GS), NADHglutamate synthetase (GOGAT), nitrate reductase (NR), nitrogenase and alkaline phosphatase (AP) in response to low Cu 2+ concentrations was noted. However, higher ones inhibited the enzymes activities with different degrees. The enzymes could be arranged according to their tolerance to Cu 2+ toxicity in the following order: AP > NR > GOGAT > GS > nitrogenase.
Page 1. eschweizerbartxxx ingenta Influence of the aqueous extracts of Ulva lactuca and Chlorella... more Page 1. eschweizerbartxxx ingenta Influence of the aqueous extracts of Ulva lactuca and Chlorella kessleri on growth and yield of Vicia faba By AMAL H. EL-NAGGAR, MOHAMED EH OSMAN, MOSTAFA M. EL-SHEEKH and SALY F. GHEDA ...
The impact of two intensities (2.5 and 5 W m -2 ) of ultraviolet-B (UV-B) radiation on lipid pero... more The impact of two intensities (2.5 and 5 W m -2 ) of ultraviolet-B (UV-B) radiation on lipid peroxidation, protein pattern and some antioxidant enzymes including superoxide dismutase, catalase and peroxidase has been studied in Chlorococcum sp. isolated from El-Kased freshwater canal, Tanta, Egypt. Exposure of Chlorococcum sp. for 2 h to 2.5 and 5 W m -2 increased malondialdehyde (MDA) content by 238 and 274%, respectively. The activity of superoxide dismutase and peroxidase were increased at all exposure times at both intensities. In contrast, the activity of catalase was inhibited by increasing UV-B intensity as well as exposure time compared to the control. The reduction in catalase activity reached 71.8 and 95.9% after 2 h of exposure to 2.5 and 5 W m -2 , respectively. With regard to protein pattern, exposure of Chlorococcum sp. to UV-B stress induced marked changes in protein synthesis patterns. Three types of alterations were noticed, i) significant reduction in the biosynthesis of certain proteins, ii) induction of specific proteins biosynthesis and iii) changes in band intensities of some proteins.
Page 1. COMPARATIVE STUDIES ON THE GREEN ALGAE CHLORELLA HOMOSPHAERA AND CHLORELLA VULGARIS WITH ... more Page 1. COMPARATIVE STUDIES ON THE GREEN ALGAE CHLORELLA HOMOSPHAERA AND CHLORELLA VULGARIS WITH RESPECT TO OIL POLLUTION IN THE RIVER NILE MOSTAFA M. EL-SHEEKH ∗ , AMAL H. EL ...
Two cyanobacterial species (Nostoc entophytum and Oscillatoria angustissima) were tested as biofe... more Two cyanobacterial species (Nostoc entophytum and Oscillatoria angustissima) were tested as biofertilizers, substituting the normally used chemical fertilizer, for pea plant. Inoculation of soil with a suspension of each species or a combination of the two species significantly increased the germination percentage and stimulated the other measured growth parameters and photosynthetic pigment fractions of pea. However, the soil inoculation with one cyanobacterial species and the addition of the recommended dose or half the recommended dose of chemical fertilizer were usually more effective and also increased carbohydrate and protein contents of produced pea seeds. However, biofertilization combined with half the recommended dose of the chemical fertilizer was usually more effective than the addition of the full rate of the chemical fertilizer, and this may allow saving 50% of the used chemical fertilizer. The protein profile of the produced seeds showed appearance and disappearance of some protein bands in response to fertilization treatments compared to the control. Blue green algae analyses show that N. entophytum fixed more N, produced more exopolysaccharide, and contained more auxin and cytokinin than O. angustissima, the latter contained more gibberellins. These data may explain their different influences on growth and yield of pea.
The impact of two intensities (2.5 W m -2 and 5 W m -2 ) of ultraviolet-B (UV-B) radiation on gro... more The impact of two intensities (2.5 W m -2 and 5 W m -2 ) of ultraviolet-B (UV-B) radiation on growth, photosynthetic pigments, photosynthetic activity and membrane leakage has been studied in Chlorococcum sp. isolated from El-Kased fresh water canal, Tanta, Egypt. Exposure of Chlorococcum sp. for 60 and 35 min of 2.5 and 5 W m -2 , respectively, inhibited growth by 50%. Chlorophyll a and chlorophyll b were decreased in Chlorococcum sp. by exposure to UV-B, but the effect was more pronounced on chlorophyll b. On the other hand, carotenoids were stimulated at small doses (time of exposure and intensity) of UV-B whether at 2.5 or 5 W m -2 . However, oxygen amount, total soluble carbohydrates, and total soluble proteins were inhibited by UV-B treatment at all exposure times but the effect of 5 W m -2 was more than that of 2.5 W m -2 and O 2 was completely abolished after 90 and 120 min at 2.5 and 5 W m -2 , respectively. With regard to extracellular polysaccharides, there was a significant increase at small doses of UV-B but reduction observed at high doses. Exposing cells to 2.5 and 5 W m -2 UV-B caused 22.7 and 39.6% increase, respectively, in electrolyte leakage than in control.
Page 1. eschweizerbartxxx ingenta Influence of the aqueous extracts of Ulva lactuca and Chlorella... more Page 1. eschweizerbartxxx ingenta Influence of the aqueous extracts of Ulva lactuca and Chlorella kessleri on growth and yield of Vicia faba By AMAL H. EL-NAGGAR, MOHAMED EH OSMAN, MOSTAFA M. EL-SHEEKH and SALY F. GHEDA ...
Growth, morphological changes, amino acid composition, total soluble protein, and protein electro... more Growth, morphological changes, amino acid composition, total soluble protein, and protein electrophoretic pattern were monitored for Scenedesmus obliquus and Nitzschia perminuta grown in the presence of different concentrations of Co(2+) and Ni(2+). Lower concentrations of cobalt stimulated the dry mass production and total soluble protein content of the two algae, whereas higher concentrations were inhibitory. Generally, N. perminuta showed more tolerance to the phytotoxicity of the two metals than S. obliquus and more tolerance to nickel than cobalt. However, S. obliquus seems to be more tolerant to cobalt than nickel. Cobalt and nickel have induced an increase in cell volume, change and disorder in cell shape. The increase in cell volume was much observed in Ni(2+) treated cells. At the same time, the two metals did not induce any distinct morphological abnormalities in N. perminuta. Co(2+) has stimulated the biosynthesis of all free amino acids in S. obliquus, except aspartic acid and phenylalanine, whereas Ni(2+) caused 22% inhibition in the content of total free amino acids, except cystine and arginine. On the other hand, Co(2+) has reduced the content of free amino acids in N. perminuta, except cystine, methionine, valine, and lysine. On the other hand, Ni(2+) stimulated the biosynthesis of glycine, alanine and histidine and highly stimulated valine and sulphur containing amino acids (cystine and methionine) in N. perminuta. High cobalt concentration (4ppm) resulted in the disappearance of 28.7kDa protein, 3.5ppm Ni(2+) stimulated the appearance of 18 and 20kDa proteins in S. Obliquus, while 37kDa proteins disappeared from N. perminuta treated with high doses of Co(2+) and Ni(2+).
Page 1. COMPARATIVE STUDIES ON THE GREEN ALGAE CHLORELLA HOMOSPHAERA AND CHLORELLA VULGARIS WITH ... more Page 1. COMPARATIVE STUDIES ON THE GREEN ALGAE CHLORELLA HOMOSPHAERA AND CHLORELLA VULGARIS WITH RESPECT TO OIL POLLUTION IN THE RIVER NILE MOSTAFA M. EL-SHEEKH ∗ , AMAL H. EL ...
Abstract Waste-to-energy is a promising approach to tackle the energy shortage and reduce the env... more Abstract Waste-to-energy is a promising approach to tackle the energy shortage and reduce the environmental pollution. The present study aimed to evaluate the technical and economic feasibility of microwave vacuum co-pyrolysis of seaweeds and low-density polyethylene (LDPE). Although the three studied seaweeds namely; Ulva intestinalis, Sargassum polycystum, and Hypnea valentiae showed similar thermal weight loss profile, U. intestinalis showed the highest biomass and bio-oil yields which resulted in superior bio-oil areal productivity of 30.1 g m−2. Therefore, it was selected for co-pyrolysis with LDPE at different blend ratios. Compared to individual pyrolysis of U. intestinalis, the increase inLDPE ratio enhanced the crude bio-oil production with simultaneous reduction in bio-char yield. The experimental bio-oil yields from co-pyrolysis showed higher values than the corresponding theoretical values, confirming a synergistic effect between the two feedstocks. The bio-oil produced from co-pyrolysis at 75% LDPE blend ratio showed better characteristics compared to the individual pyrolysis. Van Krevelen plot suggested that LDPE produces hydrogen radicals during co-pyrolysis reactions, which increased the H/C ratio and reduced the O/C ratio. GC/MS analysis confirmed that the increase in LDPE stimulates hydrocarbons proportion up to 51.2% at 75% blend ratio with significant reduction in N-containing compounds, carboxylic acids, furans, aldehydes/ketones, saccharides, and phenols. The economic feasibility analysis at a feedstock feeding rate of 11.4 ton h−1 using Aspen Plus showed estimated net profit of 23.17 million US$ for a 20-years life time plant. The present study provides a potential approach for sustainable energy recovery from waste plastic/seaweeds blend using microwave vacuum co-pyrolysis.
Growth and some metabolic activities of two cyanobacterial species (Anabaena subcylindrica and No... more Growth and some metabolic activities of two cyanobacterial species (Anabaena subcylindrica and Nostoc Linckia) grown under salinity stress with and without exogeneously added calcium chloride were monitored. Salinity treatment (0.3M NaCl) induced pronounced reduction in growth, pigment fractions, carbohydrates, O 2-evolution, respiration, lipids content and increase in the measured elements content (Na + , K + , Mg ++ , Fe +++ and Ca ++). Presence of Ca 2+ (0.03 or 0.05 M CaCl 2) caused significant recovery of the different measured growth parameters and metabolic activities. The most important changes induced by salinity treatment are:1-Reduction in the polysaccharides content of both organisms accompanied with an increase in the soluble sugars, which proposed that the possible inhibitory effect of salinity associated with osmotic regulation. This effect could be ameliorated by addition of calcium ions. 2-The integrity of the plasma membranes impaired by salinity. Presence of calcium protects the membranes against the injury induced by salinity.
In the present study, fifteen species of the dominant marine algae were collected during summer 2... more In the present study, fifteen species of the dominant marine algae were collected during summer 2013 from four selected sites on Red sea coast, Jeddah, Saudi Arabia. The collected species belonged to Chlorophyta, Phaeophyta and Rhodophyta. Crude algal extracts were prepared by successive extractions using different solvents (acetone, ethanol, diethyl ether, ethyl acetate, methanol and petroleum ether). The crude algal extracts were examined for their antifungal efficacy against Aspergillus flavus, Aspergillus fumigatus, Aspergillus niger, Candida albicans and Candida tropicalis using agar well diffusion method. The algal extracts evoked different patterns of antifungal activities. Results reveal that acetone was the best solvent suited for extraction of bioactive compounds from tested seaweeds with inhibition activity (19.3%) followed by ethyl acetate (17.1%), ethanol (16.4%), petroleum ether (15.9%), diethyl ether (15.85%), and finally methanol (15.4%). Chlorophyta exhibited the highest antimycotic effect followed by Rhodophyta and Phaeophyta. In Chlorophyta, the extracts of Ulva intestinalis were the most potent followed by U. lactuca, C. racemosa, U. linza and U. reticulate. Acanthophora spicifera showed the highest activity in Rhodophyta, followed by J. rubens, D. simplex, L. obtusa, G. gracilis, G. vermicuphylla and G. multipartita. Whereas, T. triquetra was the most effective species in Phaeophyta followed by P. pavonica and D. dichotoma. The minimal inhibitory concentrations (MICs) of the most potent algal extracts were in the range of 0.5 to 4 mg/ml. The results confirmed the antimycotic potentiality of seaweed extracts.
The unicellular green alga Monoraphidium minutum and the diatom Nitzschia perminuta were cultured... more The unicellular green alga Monoraphidium minutum and the diatom Nitzschia perminuta were cultured under different concentrations of Co2+. Growth and pigment content were slightly increased at low concentrations and inhibited by high Co2+ concentrations. The results concerning the effect of different concentrations of Co2+ on photosynthetic O2 evolution showed a reduction in the amount of O2 evolved by each alga in response to increasing Co2+ concentrations. However, an increase in O2 evolution for both M. minutum and N. perminuta was observed at relatively low Co2+ concentrations. Photosynthetic electron transport in M. minutum was more sensitive to Co2+ toxicity than in N. perminuta. On the other hand, the effect of the heavy metal on respiration showed that higher Co2+ concentrations were inhibitory to O2 uptake by the two algal species. Low Co2+ concentrations stimulated O2 uptake by M. minutum throughout the experimental period. However, in N. perminuta, different concentrations...
The influence of Cu 2+ toxicity on dry mass, chl.a, carotenoids, protein content, Cu 2+ uptake, a... more The influence of Cu 2+ toxicity on dry mass, chl.a, carotenoids, protein content, Cu 2+ uptake, activities of some enzymes of nitrogen assimilation and alkaline phosphatase in the diazotrophic cyanobacterium Anabaena variabilis was evaluated. Lower Cu 2+ concentrations stimulated the dry weight, chl.a, and protein content, whereas, higher concentrations were inhibitory. In contrast, a prominent increase in the carotenoids content was detected in response to all Cu 2+ treatments. A. variabilis showed high uptake capacity of Cu 2+. The accumulation capacity is directly proportional to the external Cu 2+ concentrations. A stimulation in the activities of glutamine synthetase (GS), NADHglutamate synthetase (GOGAT), nitrate reductase (NR), nitrogenase and alkaline phosphatase (AP) in response to low Cu 2+ concentrations was noted. However, higher ones inhibited the enzymes activities with different degrees. The enzymes could be arranged according to their tolerance to Cu 2+ toxicity in the following order: AP > NR > GOGAT > GS > nitrogenase.
Page 1. eschweizerbartxxx ingenta Influence of the aqueous extracts of Ulva lactuca and Chlorella... more Page 1. eschweizerbartxxx ingenta Influence of the aqueous extracts of Ulva lactuca and Chlorella kessleri on growth and yield of Vicia faba By AMAL H. EL-NAGGAR, MOHAMED EH OSMAN, MOSTAFA M. EL-SHEEKH and SALY F. GHEDA ...
The impact of two intensities (2.5 and 5 W m -2 ) of ultraviolet-B (UV-B) radiation on lipid pero... more The impact of two intensities (2.5 and 5 W m -2 ) of ultraviolet-B (UV-B) radiation on lipid peroxidation, protein pattern and some antioxidant enzymes including superoxide dismutase, catalase and peroxidase has been studied in Chlorococcum sp. isolated from El-Kased freshwater canal, Tanta, Egypt. Exposure of Chlorococcum sp. for 2 h to 2.5 and 5 W m -2 increased malondialdehyde (MDA) content by 238 and 274%, respectively. The activity of superoxide dismutase and peroxidase were increased at all exposure times at both intensities. In contrast, the activity of catalase was inhibited by increasing UV-B intensity as well as exposure time compared to the control. The reduction in catalase activity reached 71.8 and 95.9% after 2 h of exposure to 2.5 and 5 W m -2 , respectively. With regard to protein pattern, exposure of Chlorococcum sp. to UV-B stress induced marked changes in protein synthesis patterns. Three types of alterations were noticed, i) significant reduction in the biosynthesis of certain proteins, ii) induction of specific proteins biosynthesis and iii) changes in band intensities of some proteins.
Page 1. COMPARATIVE STUDIES ON THE GREEN ALGAE CHLORELLA HOMOSPHAERA AND CHLORELLA VULGARIS WITH ... more Page 1. COMPARATIVE STUDIES ON THE GREEN ALGAE CHLORELLA HOMOSPHAERA AND CHLORELLA VULGARIS WITH RESPECT TO OIL POLLUTION IN THE RIVER NILE MOSTAFA M. EL-SHEEKH ∗ , AMAL H. EL ...
Two cyanobacterial species (Nostoc entophytum and Oscillatoria angustissima) were tested as biofe... more Two cyanobacterial species (Nostoc entophytum and Oscillatoria angustissima) were tested as biofertilizers, substituting the normally used chemical fertilizer, for pea plant. Inoculation of soil with a suspension of each species or a combination of the two species significantly increased the germination percentage and stimulated the other measured growth parameters and photosynthetic pigment fractions of pea. However, the soil inoculation with one cyanobacterial species and the addition of the recommended dose or half the recommended dose of chemical fertilizer were usually more effective and also increased carbohydrate and protein contents of produced pea seeds. However, biofertilization combined with half the recommended dose of the chemical fertilizer was usually more effective than the addition of the full rate of the chemical fertilizer, and this may allow saving 50% of the used chemical fertilizer. The protein profile of the produced seeds showed appearance and disappearance of some protein bands in response to fertilization treatments compared to the control. Blue green algae analyses show that N. entophytum fixed more N, produced more exopolysaccharide, and contained more auxin and cytokinin than O. angustissima, the latter contained more gibberellins. These data may explain their different influences on growth and yield of pea.
The impact of two intensities (2.5 W m -2 and 5 W m -2 ) of ultraviolet-B (UV-B) radiation on gro... more The impact of two intensities (2.5 W m -2 and 5 W m -2 ) of ultraviolet-B (UV-B) radiation on growth, photosynthetic pigments, photosynthetic activity and membrane leakage has been studied in Chlorococcum sp. isolated from El-Kased fresh water canal, Tanta, Egypt. Exposure of Chlorococcum sp. for 60 and 35 min of 2.5 and 5 W m -2 , respectively, inhibited growth by 50%. Chlorophyll a and chlorophyll b were decreased in Chlorococcum sp. by exposure to UV-B, but the effect was more pronounced on chlorophyll b. On the other hand, carotenoids were stimulated at small doses (time of exposure and intensity) of UV-B whether at 2.5 or 5 W m -2 . However, oxygen amount, total soluble carbohydrates, and total soluble proteins were inhibited by UV-B treatment at all exposure times but the effect of 5 W m -2 was more than that of 2.5 W m -2 and O 2 was completely abolished after 90 and 120 min at 2.5 and 5 W m -2 , respectively. With regard to extracellular polysaccharides, there was a significant increase at small doses of UV-B but reduction observed at high doses. Exposing cells to 2.5 and 5 W m -2 UV-B caused 22.7 and 39.6% increase, respectively, in electrolyte leakage than in control.
Page 1. eschweizerbartxxx ingenta Influence of the aqueous extracts of Ulva lactuca and Chlorella... more Page 1. eschweizerbartxxx ingenta Influence of the aqueous extracts of Ulva lactuca and Chlorella kessleri on growth and yield of Vicia faba By AMAL H. EL-NAGGAR, MOHAMED EH OSMAN, MOSTAFA M. EL-SHEEKH and SALY F. GHEDA ...
Growth, morphological changes, amino acid composition, total soluble protein, and protein electro... more Growth, morphological changes, amino acid composition, total soluble protein, and protein electrophoretic pattern were monitored for Scenedesmus obliquus and Nitzschia perminuta grown in the presence of different concentrations of Co(2+) and Ni(2+). Lower concentrations of cobalt stimulated the dry mass production and total soluble protein content of the two algae, whereas higher concentrations were inhibitory. Generally, N. perminuta showed more tolerance to the phytotoxicity of the two metals than S. obliquus and more tolerance to nickel than cobalt. However, S. obliquus seems to be more tolerant to cobalt than nickel. Cobalt and nickel have induced an increase in cell volume, change and disorder in cell shape. The increase in cell volume was much observed in Ni(2+) treated cells. At the same time, the two metals did not induce any distinct morphological abnormalities in N. perminuta. Co(2+) has stimulated the biosynthesis of all free amino acids in S. obliquus, except aspartic acid and phenylalanine, whereas Ni(2+) caused 22% inhibition in the content of total free amino acids, except cystine and arginine. On the other hand, Co(2+) has reduced the content of free amino acids in N. perminuta, except cystine, methionine, valine, and lysine. On the other hand, Ni(2+) stimulated the biosynthesis of glycine, alanine and histidine and highly stimulated valine and sulphur containing amino acids (cystine and methionine) in N. perminuta. High cobalt concentration (4ppm) resulted in the disappearance of 28.7kDa protein, 3.5ppm Ni(2+) stimulated the appearance of 18 and 20kDa proteins in S. Obliquus, while 37kDa proteins disappeared from N. perminuta treated with high doses of Co(2+) and Ni(2+).
Page 1. COMPARATIVE STUDIES ON THE GREEN ALGAE CHLORELLA HOMOSPHAERA AND CHLORELLA VULGARIS WITH ... more Page 1. COMPARATIVE STUDIES ON THE GREEN ALGAE CHLORELLA HOMOSPHAERA AND CHLORELLA VULGARIS WITH RESPECT TO OIL POLLUTION IN THE RIVER NILE MOSTAFA M. EL-SHEEKH ∗ , AMAL H. EL ...
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