imane wahby - Academia.edu (original) (raw)
Papers by imane wahby
Compost Science & Utilization, Dec 19, 2023
Marina y Antonio (a ver si aprendes que la mejor terapia es la risa!!!!). …soy inmensamente agrad... more Marina y Antonio (a ver si aprendes que la mejor terapia es la risa!!!!). …soy inmensamente agradecida a ti…Mohamed…por animarme, apoyarme y no dejarme tirar la toalla en los momentos difíciles…no hay palabras que agradezcan todo tu esfuerzo…jamás has limitado mi formación aunque hemos tenido que estar separados durante años. Sabías que era bueno para mí y siempre he contado con tu apoyo. Gracias por iluminar mi camino, por el amor y la paciencia, por estar allí y aguantarme cuando las cosas me salían mal…este trabajo es mérito de los dos.
Applied Biochemistry and Biotechnology
Agroforestry Systems, 2018
Environmental Entomology, 2017
The invasive brown marmorated stink bug, Halyomorpha halys (Stål; Hemiptera: Pentatomidae), has r... more The invasive brown marmorated stink bug, Halyomorpha halys (Stål; Hemiptera: Pentatomidae), has recently emerged as a harmful pest of horticultural crops in North America and Europe. Native to East Asia, this highly polyphagous insect is spreading rapidly worldwide. Climate change will add further complications to managing this species in terms of both geographic distribution and population growth. This study used CLIMEX to compare potential H. halys distribution under recent and future climate models using one emission scenario (A2) with two different global circulation models, CSIRO Mk3.0 and MIROC-H. Simulated changes in seasonal phenology and voltinism were examined. Under the possible future climate scenarios, suitable range in Europe expands northward. In North America, the suitable H. halys range shifts northward into Canada and contracts from its southern temperature range limits in the United States due to increased heat stress. Prolonged periods of warm temperatures resulted in longer H. halys growing seasons. However, future climate scenarios indicated that rising summer temperatures decrease H. halys growth potential compared to recent climatic conditions, which in turn, may reduce midsummer crop damage. Climate change may increase the number of H. halys generations produced annually, thereby enabling the invasive insect to become multivoltine in the northern latitudes of North America and Europe where it is currently reported to be univoltine. These results indicate prime horticultural production areas in Europe, the northeastern United States, and southeastern Canada are at greatest risk from H. halys under both current and possible future climates.
Fermentation Technology, Sep 29, 2015
A decrease in the abundance and biodiversity of intestinal bacteria within the Firmicutes phylum ... more A decrease in the abundance and biodiversity of intestinal bacteria within the Firmicutes phylum has been associated with inflammatory bowel disease (IBD). In particular, the antiinflammatory bacterium Faecalibacterium prausnitzii, member of the Firmicutes phylum and one of the most abundant species in healthy human colon, is underrepresented in the microbiota of IBD patients. The aim of this study was to investigate the immunomodulatory properties of F. prausnitzii strain A2-165, the biofilm forming strain HTF-F and the extracellular polymeric matrix (EPM) isolated from strain HTF-F. For this purpose, the immunomodulatory properties of the F. prausnitzii strains and the EPM were studied in vitro using human monocyte-derived dendritic cells. Then, the capacity of the F. prausnitzii strains and the EPM of HTF-F to suppress inflammation was assessed in vivo in the mouse dextran sodium sulphate (DSS) colitis model. The F. prausnitzii strains and the EPM had anti-inflammatory effects on the clinical parameters measured in the DSS model but with different efficacy. The immunomodulatory effects of the EPM were mediated through the TLR2-dependent modulation of IL-12 and IL-10 cytokine production in antigen presenting cells, suggesting that it contributes to the anti-inflammatory potency of F. prausnitzii HTF-F. The results show that F. prausnitzii HTF-F and its EPM may have a therapeutic use in IBD.
Bioenergy Research, Nov 29, 2022
Aquaculture International, 2021
Spirulina (Arthrospira platensis) is a microscopic filamentous cyanobacterium with a long history... more Spirulina (Arthrospira platensis) is a microscopic filamentous cyanobacterium with a long history of basic and complementary alimentation. Nevertheless, a growing interest in its use in agriculture as biofertilizers and plant growth biostimulants was showed in the last years. Spirulina is commercially produced in large outdoor ponds under controlled conditions that affect both growth and biomass composition. Here, we have studied the influence of culture conditions on Spirulina growth (biomass production) and characterize the produced biomass for possible use in biopharming. The study of the effect of culture media, as well as temperature on growth and biomass composition, showed an optimal growth in temperatures at 30 and 35 °C with no difference between both tested media. The analysis of NPK content of produced biomass revealed that it contains the following: 10.9% N, 0.94% P, and 1.1 % K. In optimal growth conditions, the total biomass protein content varied from 64 to 71 %. Spirulina cells were harvested in all growth phases and analyzed for total polysaccharides (PS) in batch and continuous culture. The maximum PS production was observed during the exponential growth phase (1.5%). It was also found that the cultivation of Spirulina platensis in continuous culture increased its polysaccharide level (4.98%) compared to batch cultures.
The recent energy dependence and climate change policies encourage development and utilization of... more The recent energy dependence and climate change policies encourage development and utilization of renewable and clean energy forms worldwide. After solar and wind, biomass as source of biofuels is attracting an increased interest because of the diversity of biofuels that can be produced from this renewable resource. Among the vast array of biomasses available (waste biomass, lignocellulosic biomass, etc.), algae are regarded as the only source of renewable biofuels capable to meet the global demand for biofuels mainly for transport. Depending on the used technology, microalgal biomass can be used to produce at least 6 forms of biofuels: biodiesel, bio-oil, bioethanol, jet fuel, hydrogen and biogas, some of them are yet produced at large scale. This paper will provide an extensive review of the biofuels produced from microalgal biomass, named third generation biofuels and analyze the possibility to develop such activity in Morocco.
Hemp (Cannabis sativa L.), a difficult to transform plant, has been effectively infected with eit... more Hemp (Cannabis sativa L.), a difficult to transform plant, has been effectively infected with either Ri or Ti plasmid-bearing agrobacteria and several transformed tissues (tumors and hairy roots) were established and its transgenic nature confirmed. Hypocotyl of intact seedlings was the most responsive material and the response depended on both bacterial strain and plant variety. Transformed tissues were cultured and stabilized in vitro and showed the characteristic traits of fast and phytohormone-independent growth as well as high incidence of lateral branching and abundance of root hairs in the case of roots. The presence of some nitrogen compounds, metabolites of pharmaceutical implication, has been assayed in these transformed roots. Atropine, choline and muscarine were detected at quantitative levels in transformed roots and untransformed plant material of C. sativa. Further, the three compounds are present in hairy roots at concentrations quantitatively higher than in untransf...
Arabian Journal for Science and Engineering, 2018
The world loses 3 ha of arable lands every minute due to salinization. To counteract adverse effe... more The world loses 3 ha of arable lands every minute due to salinization. To counteract adverse effects of salinity on plants, the use of PGPR is an efficient/cheaper method that induces salt stress tolerance in plants. The aim of the present work was to study auxin production and inorganic phosphate solubilization capacities of Pseudomonas fluorescens Ms-01 (A newly isolated strain from grapevine rhizosphere) and Azosprillum brasilense DSM1690 (DSMZ strain isolated from Digitaria decumbens roots) under hypersaline conditions. The objective was to assess their synergetic action in the promotion of wheat plant growth in saline conditions. The results showed a prominent ability of the studied strains to grow in high NaCl concentrations of about 600 mM. In addition, both auxin production and phosphate solubilization activities were maintained in hypersaline conditions. In fact, with an initial IAA production of 32 µg ml −1 , A. brasilense DSM 1690 maintained a good production in hypersaline conditions (22.5 ± 4.1 µg ml −1 in 400 mM NaCl). Phosphate solubilization activity of P. fluorescens Ms-01 was also significantly improved with increase in salinity, reaching 22.6 ± 1.7 µg ml −1 P 2 O 5 in 600 mM NaCl. The inoculation of wheat plants with the studied bacteria increased the plant height and weight under normal and saline conditions. Results showed significant increase in proline accumulation and in the activity of POD and APX antioxidant enzymes in wheat plants inoculated with P. fluorescens Ms-01 in saline soil conditions. The correlation between proline accumulation and antioxidant enzymes activities indicated that the inoculation improved the defense pathway of plants against salt stress.
The Scientific World Journal, 2018
Nitrogen stress increases lipids content in microalgae, the main feedstock for algal biodiesel. S... more Nitrogen stress increases lipids content in microalgae, the main feedstock for algal biodiesel. Sodium tungstate was used in this study to implement nitrogen stress by inhibiting nitrate reductase (NR) in Dunaliella tertiolecta. The reduction of NR activity was accompanied by reduction of chlorophyll and accumulation of lipids. One-stage and two-stage culture strategies were compared. One-stage culture raised total lipids from 18% (control) to 39% (w: w); however, two-stage culture raised lipids to 50% in which neutral lipids were enhanced 2.14 times. To assess the quality of biodiesel produced, fatty acid methyl esters (FAME) composition was studied. It showed a slight variation of unsaturation. In addition, some physical proprieties of biodiesel were estimated and showed that higher heating values were improved by tungstate treatment. In this study, we tried to shed light on some biological impact of NR inhibition in microalgae cells using sodium tungstate which could be exploited...
Renewable Energy, 2017
Microalgae as feedstock of bioenergy, mainly biodiesel, is receiving an increased attention from ... more Microalgae as feedstock of bioenergy, mainly biodiesel, is receiving an increased attention from scientific and industrial point of view. The selection of promising strains and optimization of the production process are essential keys to develop an economically viable project. In this context, fifty-seven strains of marine microalgae have been isolated from the Moroccan Atlantic and Mediterranean coasts. The selection of most promising strains was based on biomass productivity, lipid content and fatty acids profile. Nannochloropsis gaditana (24), Chlorella sp (67), Dunaliella tertiolecta (29), Isochrysis sp (77), Phaeodactylium tricornutum (23) and Chaetoceros sp (63) showed the best growth rate, whereas lipid content was highest in Navicula sp (up to 63%) and Tetraselmis sp (up to 56%), Dunaliella sp (up to 50%), Nannochloropsis sp (up to.60%) and Chaetoceros sp (up to 56%). Fatty Acids Methyl Ester profiles were analyzed and most strains studied showed a high rate of PUFA's mainly those belonging of Dunaliella, Tetraselmis, Isochrysis and Nannochlorpsis genuis. For Bacillariophyceae, despite their high content in lipids, their FAME profile was rich in PUFA's which affects the quality of biodiesel. This study describes the microalgae screening process and demonstrates that Nannochloropsis sp, Dunaliella tertiolecta, Isochrysis sp and Tetraselmis sp are among promising species as biodiesel feedstock.
Journal of microbiology, biotechnology and food sciences, 2017
The present investigation aimed to study antimicrobial activities in marine microalgae, screened ... more The present investigation aimed to study antimicrobial activities in marine microalgae, screened from Moroccan coastlines. Ethanolic extracts were prepared from the microalgae and evaluated each against the bacteria: Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, the yeast Candida albicans and the fungus Aspergillus niger. The highest antibacterial activity was found in the extract of Tetraselmis sp. which exhibited an inhibitory effect against the three bacteria with a MIC of 2.6 to 3.0 mg extract per mL culture. Extracts from the other microalgae: Dunaliella Salina, Nannochloropsis gaditana, Dunaliella sp., Phaeodactylum tricornutum and Isochrisis sp. each showed inhibitory activity against E. coli or P. aeruginosa with a MIC of 2.6 to 4.3 mg extract per mL. The extract of N. gaditana also inhibited S. aureus growth. However, the extracts from the microalgae, Chaetoceros sp. and Chlorella sp. showed no effect under the applied experimental conditions. All the ...
Acta Horticulturae, 2016
Salinity is among the major limiting factors of crop productivity worldwide. Salt stress affects ... more Salinity is among the major limiting factors of crop productivity worldwide. Salt stress affects the plant growth at all developmental stages. The present study investigates the potential of halotolerant microalgae Dunaliella salina extracts to suppress the inhibition of seeds germination and seedlings growth caused by salt stress on wheat (Triticum aestivum). Germination percentage and height of coleoptiles and root system were measured as a response of D. salina extracts treatment. Biomass hydrolyzate of D. salina cultured in different concentrations of NaCl (1, 2 and 4 M of NaCl) improved germination and seedling growth of wheat under salt stress. The effect of molecules accumulated in D. salina which are proline, carotenoids and exopolysaccharides on germination and seedling growth was investigated. Our results showed that exopolysaccharides extracted from the microalgae had the major stimulating effect on germination and seedling growth in wheat. Exopolysaccharides extracts from D. salina improved the germination percentage of wheat seeds under salt stress of 3 and 6 g L-1 NaCl by 96 and 83%, respectively, compared to control, while the height of root system was stimulated with 133 and 444% and the coleoptiles height was increased by 105 and 750% in response to 3 and 6 g L-1 NaCl, respectively, compared to control stressed untreated. Our study demonstrates that extracts of halotolerant microalgae especially exopolysaccharides could help plants to tolerate salt stress.
International Journal of Innovation and Applied Studies, Apr 28, 2014
The decrease of petroleum reserves and the global increase in energy demand has resulted in the f... more The decrease of petroleum reserves and the global increase in energy demand has resulted in the focus of research toward exploration of alternate fuels using biological renewable sources. Biodiesel is one of these renewable energy forms. Microalgae are considered one of the most promising sources for biodiesel production. However, the potential use of microalgae in this field still needs to be explored since only about twenty species has been studied from the approximately 30.000 known species. Thereby, screening work on new potentially lipid overproducer strains is actually an active field. An overview of potential applications of multi-parameter flow cytometry in development of a biodiesel production strategy using microalgae is detailed in this review. Rapid and simultaneous measurements of different physiological parameters indicating diversity in marine and freshwater microalgal communities, biomass quality such as biochemical composition and viability of individual cells, isolation of targeted cells and obtention of axenic cultures are applications of flow cytometry that enable monitoring and optimisation of production of lipids from microalgae.
International Journal of Innovation and Applied Studies, Apr 28, 2014
The decrease of petroleum reserves and the global increase in energy demand has resulted in the f... more The decrease of petroleum reserves and the global increase in energy demand has resulted in the focus of research toward exploration of alternate fuels using biological renewable sources. Biodiesel is one of these renewable energy forms. Microalgae are considered one of the most promising sources for biodiesel production. However, the potential use of microalgae in this field still needs to be explored since only about twenty species has been studied from the approximately 30.000 known species. Thereby, screening work on new potentially lipid overproducer strains is actually an active field. An overview of potential applications of multi-parameter flow cytometry in development of a biodiesel production strategy using microalgae is detailed in this review. Rapid and simultaneous measurements of different physiological parameters indicating diversity in marine and freshwater microalgal communities, biomass quality such as biochemical composition and viability of individual cells, isolation of targeted cells and obtention of axenic cultures are applications of flow cytometry that enable monitoring and optimisation of production of lipids from microalgae.
International Journal of Innovation and Applied Studies, Apr 28, 2014
Journal of Plant Interactions, 2013
Compost Science & Utilization, Dec 19, 2023
Marina y Antonio (a ver si aprendes que la mejor terapia es la risa!!!!). …soy inmensamente agrad... more Marina y Antonio (a ver si aprendes que la mejor terapia es la risa!!!!). …soy inmensamente agradecida a ti…Mohamed…por animarme, apoyarme y no dejarme tirar la toalla en los momentos difíciles…no hay palabras que agradezcan todo tu esfuerzo…jamás has limitado mi formación aunque hemos tenido que estar separados durante años. Sabías que era bueno para mí y siempre he contado con tu apoyo. Gracias por iluminar mi camino, por el amor y la paciencia, por estar allí y aguantarme cuando las cosas me salían mal…este trabajo es mérito de los dos.
Applied Biochemistry and Biotechnology
Agroforestry Systems, 2018
Environmental Entomology, 2017
The invasive brown marmorated stink bug, Halyomorpha halys (Stål; Hemiptera: Pentatomidae), has r... more The invasive brown marmorated stink bug, Halyomorpha halys (Stål; Hemiptera: Pentatomidae), has recently emerged as a harmful pest of horticultural crops in North America and Europe. Native to East Asia, this highly polyphagous insect is spreading rapidly worldwide. Climate change will add further complications to managing this species in terms of both geographic distribution and population growth. This study used CLIMEX to compare potential H. halys distribution under recent and future climate models using one emission scenario (A2) with two different global circulation models, CSIRO Mk3.0 and MIROC-H. Simulated changes in seasonal phenology and voltinism were examined. Under the possible future climate scenarios, suitable range in Europe expands northward. In North America, the suitable H. halys range shifts northward into Canada and contracts from its southern temperature range limits in the United States due to increased heat stress. Prolonged periods of warm temperatures resulted in longer H. halys growing seasons. However, future climate scenarios indicated that rising summer temperatures decrease H. halys growth potential compared to recent climatic conditions, which in turn, may reduce midsummer crop damage. Climate change may increase the number of H. halys generations produced annually, thereby enabling the invasive insect to become multivoltine in the northern latitudes of North America and Europe where it is currently reported to be univoltine. These results indicate prime horticultural production areas in Europe, the northeastern United States, and southeastern Canada are at greatest risk from H. halys under both current and possible future climates.
Fermentation Technology, Sep 29, 2015
A decrease in the abundance and biodiversity of intestinal bacteria within the Firmicutes phylum ... more A decrease in the abundance and biodiversity of intestinal bacteria within the Firmicutes phylum has been associated with inflammatory bowel disease (IBD). In particular, the antiinflammatory bacterium Faecalibacterium prausnitzii, member of the Firmicutes phylum and one of the most abundant species in healthy human colon, is underrepresented in the microbiota of IBD patients. The aim of this study was to investigate the immunomodulatory properties of F. prausnitzii strain A2-165, the biofilm forming strain HTF-F and the extracellular polymeric matrix (EPM) isolated from strain HTF-F. For this purpose, the immunomodulatory properties of the F. prausnitzii strains and the EPM were studied in vitro using human monocyte-derived dendritic cells. Then, the capacity of the F. prausnitzii strains and the EPM of HTF-F to suppress inflammation was assessed in vivo in the mouse dextran sodium sulphate (DSS) colitis model. The F. prausnitzii strains and the EPM had anti-inflammatory effects on the clinical parameters measured in the DSS model but with different efficacy. The immunomodulatory effects of the EPM were mediated through the TLR2-dependent modulation of IL-12 and IL-10 cytokine production in antigen presenting cells, suggesting that it contributes to the anti-inflammatory potency of F. prausnitzii HTF-F. The results show that F. prausnitzii HTF-F and its EPM may have a therapeutic use in IBD.
Bioenergy Research, Nov 29, 2022
Aquaculture International, 2021
Spirulina (Arthrospira platensis) is a microscopic filamentous cyanobacterium with a long history... more Spirulina (Arthrospira platensis) is a microscopic filamentous cyanobacterium with a long history of basic and complementary alimentation. Nevertheless, a growing interest in its use in agriculture as biofertilizers and plant growth biostimulants was showed in the last years. Spirulina is commercially produced in large outdoor ponds under controlled conditions that affect both growth and biomass composition. Here, we have studied the influence of culture conditions on Spirulina growth (biomass production) and characterize the produced biomass for possible use in biopharming. The study of the effect of culture media, as well as temperature on growth and biomass composition, showed an optimal growth in temperatures at 30 and 35 °C with no difference between both tested media. The analysis of NPK content of produced biomass revealed that it contains the following: 10.9% N, 0.94% P, and 1.1 % K. In optimal growth conditions, the total biomass protein content varied from 64 to 71 %. Spirulina cells were harvested in all growth phases and analyzed for total polysaccharides (PS) in batch and continuous culture. The maximum PS production was observed during the exponential growth phase (1.5%). It was also found that the cultivation of Spirulina platensis in continuous culture increased its polysaccharide level (4.98%) compared to batch cultures.
The recent energy dependence and climate change policies encourage development and utilization of... more The recent energy dependence and climate change policies encourage development and utilization of renewable and clean energy forms worldwide. After solar and wind, biomass as source of biofuels is attracting an increased interest because of the diversity of biofuels that can be produced from this renewable resource. Among the vast array of biomasses available (waste biomass, lignocellulosic biomass, etc.), algae are regarded as the only source of renewable biofuels capable to meet the global demand for biofuels mainly for transport. Depending on the used technology, microalgal biomass can be used to produce at least 6 forms of biofuels: biodiesel, bio-oil, bioethanol, jet fuel, hydrogen and biogas, some of them are yet produced at large scale. This paper will provide an extensive review of the biofuels produced from microalgal biomass, named third generation biofuels and analyze the possibility to develop such activity in Morocco.
Hemp (Cannabis sativa L.), a difficult to transform plant, has been effectively infected with eit... more Hemp (Cannabis sativa L.), a difficult to transform plant, has been effectively infected with either Ri or Ti plasmid-bearing agrobacteria and several transformed tissues (tumors and hairy roots) were established and its transgenic nature confirmed. Hypocotyl of intact seedlings was the most responsive material and the response depended on both bacterial strain and plant variety. Transformed tissues were cultured and stabilized in vitro and showed the characteristic traits of fast and phytohormone-independent growth as well as high incidence of lateral branching and abundance of root hairs in the case of roots. The presence of some nitrogen compounds, metabolites of pharmaceutical implication, has been assayed in these transformed roots. Atropine, choline and muscarine were detected at quantitative levels in transformed roots and untransformed plant material of C. sativa. Further, the three compounds are present in hairy roots at concentrations quantitatively higher than in untransf...
Arabian Journal for Science and Engineering, 2018
The world loses 3 ha of arable lands every minute due to salinization. To counteract adverse effe... more The world loses 3 ha of arable lands every minute due to salinization. To counteract adverse effects of salinity on plants, the use of PGPR is an efficient/cheaper method that induces salt stress tolerance in plants. The aim of the present work was to study auxin production and inorganic phosphate solubilization capacities of Pseudomonas fluorescens Ms-01 (A newly isolated strain from grapevine rhizosphere) and Azosprillum brasilense DSM1690 (DSMZ strain isolated from Digitaria decumbens roots) under hypersaline conditions. The objective was to assess their synergetic action in the promotion of wheat plant growth in saline conditions. The results showed a prominent ability of the studied strains to grow in high NaCl concentrations of about 600 mM. In addition, both auxin production and phosphate solubilization activities were maintained in hypersaline conditions. In fact, with an initial IAA production of 32 µg ml −1 , A. brasilense DSM 1690 maintained a good production in hypersaline conditions (22.5 ± 4.1 µg ml −1 in 400 mM NaCl). Phosphate solubilization activity of P. fluorescens Ms-01 was also significantly improved with increase in salinity, reaching 22.6 ± 1.7 µg ml −1 P 2 O 5 in 600 mM NaCl. The inoculation of wheat plants with the studied bacteria increased the plant height and weight under normal and saline conditions. Results showed significant increase in proline accumulation and in the activity of POD and APX antioxidant enzymes in wheat plants inoculated with P. fluorescens Ms-01 in saline soil conditions. The correlation between proline accumulation and antioxidant enzymes activities indicated that the inoculation improved the defense pathway of plants against salt stress.
The Scientific World Journal, 2018
Nitrogen stress increases lipids content in microalgae, the main feedstock for algal biodiesel. S... more Nitrogen stress increases lipids content in microalgae, the main feedstock for algal biodiesel. Sodium tungstate was used in this study to implement nitrogen stress by inhibiting nitrate reductase (NR) in Dunaliella tertiolecta. The reduction of NR activity was accompanied by reduction of chlorophyll and accumulation of lipids. One-stage and two-stage culture strategies were compared. One-stage culture raised total lipids from 18% (control) to 39% (w: w); however, two-stage culture raised lipids to 50% in which neutral lipids were enhanced 2.14 times. To assess the quality of biodiesel produced, fatty acid methyl esters (FAME) composition was studied. It showed a slight variation of unsaturation. In addition, some physical proprieties of biodiesel were estimated and showed that higher heating values were improved by tungstate treatment. In this study, we tried to shed light on some biological impact of NR inhibition in microalgae cells using sodium tungstate which could be exploited...
Renewable Energy, 2017
Microalgae as feedstock of bioenergy, mainly biodiesel, is receiving an increased attention from ... more Microalgae as feedstock of bioenergy, mainly biodiesel, is receiving an increased attention from scientific and industrial point of view. The selection of promising strains and optimization of the production process are essential keys to develop an economically viable project. In this context, fifty-seven strains of marine microalgae have been isolated from the Moroccan Atlantic and Mediterranean coasts. The selection of most promising strains was based on biomass productivity, lipid content and fatty acids profile. Nannochloropsis gaditana (24), Chlorella sp (67), Dunaliella tertiolecta (29), Isochrysis sp (77), Phaeodactylium tricornutum (23) and Chaetoceros sp (63) showed the best growth rate, whereas lipid content was highest in Navicula sp (up to 63%) and Tetraselmis sp (up to 56%), Dunaliella sp (up to 50%), Nannochloropsis sp (up to.60%) and Chaetoceros sp (up to 56%). Fatty Acids Methyl Ester profiles were analyzed and most strains studied showed a high rate of PUFA's mainly those belonging of Dunaliella, Tetraselmis, Isochrysis and Nannochlorpsis genuis. For Bacillariophyceae, despite their high content in lipids, their FAME profile was rich in PUFA's which affects the quality of biodiesel. This study describes the microalgae screening process and demonstrates that Nannochloropsis sp, Dunaliella tertiolecta, Isochrysis sp and Tetraselmis sp are among promising species as biodiesel feedstock.
Journal of microbiology, biotechnology and food sciences, 2017
The present investigation aimed to study antimicrobial activities in marine microalgae, screened ... more The present investigation aimed to study antimicrobial activities in marine microalgae, screened from Moroccan coastlines. Ethanolic extracts were prepared from the microalgae and evaluated each against the bacteria: Escherichia coli, Pseudomonas aeruginosa and Staphylococcus aureus, the yeast Candida albicans and the fungus Aspergillus niger. The highest antibacterial activity was found in the extract of Tetraselmis sp. which exhibited an inhibitory effect against the three bacteria with a MIC of 2.6 to 3.0 mg extract per mL culture. Extracts from the other microalgae: Dunaliella Salina, Nannochloropsis gaditana, Dunaliella sp., Phaeodactylum tricornutum and Isochrisis sp. each showed inhibitory activity against E. coli or P. aeruginosa with a MIC of 2.6 to 4.3 mg extract per mL. The extract of N. gaditana also inhibited S. aureus growth. However, the extracts from the microalgae, Chaetoceros sp. and Chlorella sp. showed no effect under the applied experimental conditions. All the ...
Acta Horticulturae, 2016
Salinity is among the major limiting factors of crop productivity worldwide. Salt stress affects ... more Salinity is among the major limiting factors of crop productivity worldwide. Salt stress affects the plant growth at all developmental stages. The present study investigates the potential of halotolerant microalgae Dunaliella salina extracts to suppress the inhibition of seeds germination and seedlings growth caused by salt stress on wheat (Triticum aestivum). Germination percentage and height of coleoptiles and root system were measured as a response of D. salina extracts treatment. Biomass hydrolyzate of D. salina cultured in different concentrations of NaCl (1, 2 and 4 M of NaCl) improved germination and seedling growth of wheat under salt stress. The effect of molecules accumulated in D. salina which are proline, carotenoids and exopolysaccharides on germination and seedling growth was investigated. Our results showed that exopolysaccharides extracted from the microalgae had the major stimulating effect on germination and seedling growth in wheat. Exopolysaccharides extracts from D. salina improved the germination percentage of wheat seeds under salt stress of 3 and 6 g L-1 NaCl by 96 and 83%, respectively, compared to control, while the height of root system was stimulated with 133 and 444% and the coleoptiles height was increased by 105 and 750% in response to 3 and 6 g L-1 NaCl, respectively, compared to control stressed untreated. Our study demonstrates that extracts of halotolerant microalgae especially exopolysaccharides could help plants to tolerate salt stress.
International Journal of Innovation and Applied Studies, Apr 28, 2014
The decrease of petroleum reserves and the global increase in energy demand has resulted in the f... more The decrease of petroleum reserves and the global increase in energy demand has resulted in the focus of research toward exploration of alternate fuels using biological renewable sources. Biodiesel is one of these renewable energy forms. Microalgae are considered one of the most promising sources for biodiesel production. However, the potential use of microalgae in this field still needs to be explored since only about twenty species has been studied from the approximately 30.000 known species. Thereby, screening work on new potentially lipid overproducer strains is actually an active field. An overview of potential applications of multi-parameter flow cytometry in development of a biodiesel production strategy using microalgae is detailed in this review. Rapid and simultaneous measurements of different physiological parameters indicating diversity in marine and freshwater microalgal communities, biomass quality such as biochemical composition and viability of individual cells, isolation of targeted cells and obtention of axenic cultures are applications of flow cytometry that enable monitoring and optimisation of production of lipids from microalgae.
International Journal of Innovation and Applied Studies, Apr 28, 2014
The decrease of petroleum reserves and the global increase in energy demand has resulted in the f... more The decrease of petroleum reserves and the global increase in energy demand has resulted in the focus of research toward exploration of alternate fuels using biological renewable sources. Biodiesel is one of these renewable energy forms. Microalgae are considered one of the most promising sources for biodiesel production. However, the potential use of microalgae in this field still needs to be explored since only about twenty species has been studied from the approximately 30.000 known species. Thereby, screening work on new potentially lipid overproducer strains is actually an active field. An overview of potential applications of multi-parameter flow cytometry in development of a biodiesel production strategy using microalgae is detailed in this review. Rapid and simultaneous measurements of different physiological parameters indicating diversity in marine and freshwater microalgal communities, biomass quality such as biochemical composition and viability of individual cells, isolation of targeted cells and obtention of axenic cultures are applications of flow cytometry that enable monitoring and optimisation of production of lipids from microalgae.
International Journal of Innovation and Applied Studies, Apr 28, 2014
Journal of Plant Interactions, 2013