The growth and some metablic activites of Anabaena circinalis, which were grown under different salinity stress levels were followed and it has been found that these species can tolerate NaCl salinity to the level of 80 mM and survived to the level of 0.5 M of NaCl. Higher doses of salinity caused reduction in growth criteria (Absorbance, chlorophyll content) with the time elapsed, reduction of protein content, and caused increasing in carbohydrate content, significance increasing in proline content was also recorded. Addition of Ca+2 to the salinized culture caused improvement in growth and improved K+/Na+ ratio which increase the osmoprotectant, as well as protect this organism from the toxic effect of NaCl.

The effect of glyphosate herbicide concentrations on the growth and some metabolic activities of the green alga Scenedesmus quadricauda and the blue-green alga (cyanobacteria) Merismopedia glauca isolated from soil (Assiut, Egypt) were assessed. The growth of Scenedesmus quadricauda and Merismopedia glauca was negatively affected by glyphosate herbicide. In addition, decreasing of the cell number as well as chlorophyll a, b and the dry weight of Scenedesmus were occurred with increasing the herbicide concentrations, while the dry weight and chlorophyll a of Merismopedia was increased by low concentration of glyphosate herbicide. The photosynthesis and respiration were increased in the two algae with increasing glyphosate herbicide. Increasing of soluble and insoluble carbohydrates with increasing of the herbicide in Scenedesmus. But in case of Merismopedia glauca the soluble sugars only were enhanced by all concentrations used of the herbicide. Decreasing soluble and insoluble proteins was occurred in Scenedesmus with increasing glyphosate. Also, glutelins, globulins and prolamines were decreased with increasing of glyphosate herbicide. The insoluble proteins, glutelins, globulins were increased and soluble proteins as well as prolamines were decreased with increasing of glyphosate herbicide to Merismopedia. Free amino acids were increased by increasing glyphosate herbicide in Scenedesmus and Merismopedia. Glyphosate herbicide inhibited the growth and some metabolic activities in the tested algae, this effect depend on the algal species, the type and concentration of the herbicide.

The effect of glyphosate herbicide concentrations on the growth and some metabolic activities of the green alga Scenedesmus quadricauda and the blue-green alga (cyanobacteria) Merismopedia glauca isolated from soil (Assiut, Egypt) were assessed. The growth of Scenedesmus quadricauda and Merismopedia glauca was negatively affected by glyphosate herbicide. In addition, decreasing of the cell number as well as chlorophyll a, b and the dry weight of Scenedesmus were occurred with increasing the herbicide concentrations, while the dry weight and chlorophyll a of Merismopedia was increased by low concentration of glyphosate herbicide. The photosynthesis and respiration were increased in the two algae with increasing glyphosate herbicide. Increasing of soluble and insoluble carbohydrates with increasing of the herbicide in Scenedesmus. But in case of Merismopedia glauca the soluble sugars only were enhanced by all concentrations used of the herbicide. Decreasing soluble and insoluble proteins was occurred in Scenedesmus with increasing glyphosate. Also, glutelins, globulins and prolamines were decreased with increasing of glyphosate herbicide. The insoluble proteins, glutelins, globulins were increased and soluble proteins as well as prolamines were decreased with increasing of glyphosate herbicide to Merismopedia. Free amino acids were increased by increasing glyphosate herbicide in Scenedesmus and Merismopedia. Glyphosate herbicide inhibited the growth and some metabolic activities in the tested algae, this effect depend on the algal species, the type and concentration of the herbicide.

The effect of glyphosate herbicide concentrations on the growth and some metabolic activities of the green alga Scenedesmus quadricauda and the blue-green alga (cyanobacteria) Merismopedia glauca isolated from soil (Assiut, Egypt) were assessed. The growth of Scenedesmus quadricauda and Merismopedia glauca was negatively affected by glyphosate herbicide. In addition, decreasing of the cell number as well as chlorophyll a, b and the dry weight of Scenedesmus were occurred with increasing the herbicide concentrations, while the dry weight and chlorophyll a of Merismopedia was increased by low concentration of glyphosate herbicide. The photosynthesis and respiration were increased in the two algae with increasing glyphosate herbicide. Increasing of soluble and insoluble carbohydrates with increasing of the herbicide in Scenedesmus. But in case of Merismopedia glauca the soluble sugars only were enhanced by all concentrations used of the herbicide. Decreasing soluble and insoluble proteins was occurred in Scenedesmus with increasing glyphosate. Also, glutelins, globulins and prolamines were decreased with increasing of glyphosate herbicide. The insoluble proteins, glutelins, globulins were increased and soluble proteins as well as prolamines were decreased with increasing of glyphosate herbicide to Merismopedia. Free amino acids were increased by increasing glyphosate herbicide in Scenedesmus and Merismopedia. Glyphosate herbicide inhibited the growth and some metabolic activities in the tested algae, this effect depend on the algal species, the type and concentration of the herbicide.

El-Kharga oasis soils tend to alkaline, very poor in N, P and rich in Ca, Mg, Na, and K. The total algal counts fluctuated, in the study sites (1 6), and ranged between 3.333 colonies/g soil for the plant Hyoscyamus muticus and 4978.3 colonies/g soils for Plantago major. The high percentage of cyanophyta (97.7%) was recorded around Oxalix erniculata, chlorophyta (84.1 5%) around Solanum nigrum and diatoms (53.3%) around Langonychium farctum. On the other hand, the number of total algal species in the study sites ranged between 2 and 1 6 species for Hyoscyamus muticus and Langonychium farctum, respectively. No species belong to chlorophyta and bacillariophyta around the root of Hyoscyamus muticus, Calendula micrantha and Ambrosia martema plants. The only one species encountered high occurrence remark was Pseudoanabaena papilloterminat (Cyanophyta). Treatments of Nostoc carneum with various soaked root extracts of Ambrosia maritima and Hoscyamus muticus caused enhancement of the growth, especially with high concentration of the extract (5%).

El-Kharga oasis soils tend to alkaline, very poor in N, P and rich in Ca, Mg, Na, and K. The total algal counts fluctuated, in the study sites (1 6), and ranged between 3.333 colonies/g soil for the plant Hyoscyamus muticus and 4978.3 colonies/g soils for Plantago major. The high percentage of cyanophyta (97.7%) was recorded around Oxalix erniculata, chlorophyta (84.1 5%) around Solanum nigrum and diatoms (53.3%) around Langonychium farctum. On the other hand, the number of total algal species in the study sites ranged between 2 and 1 6 species for Hyoscyamus muticus and Langonychium farctum, respectively. No species belong to chlorophyta and bacillariophyta around the root of Hyoscyamus muticus, Calendula micrantha and Ambrosia martema plants. The only one species encountered high occurrence remark was Pseudoanabaena papilloterminat (Cyanophyta). Treatments of Nostoc carneum with various soaked root extracts of Ambrosia maritima and Hoscyamus muticus caused enhancement of the growth, especially with high concentration of the extract (5%).

El-Kharga oasis soils tend to alkaline, very poor in N, P and rich in Ca, Mg, Na, and K. The total algal counts fluctuated, in the study sites (1 6), and ranged between 3.333 colonies/g soil for the plant Hyoscyamus muticus and 4978.3 colonies/g soils for Plantago major. The high percentage of cyanophyta (97.7%) was recorded around Oxalix erniculata, chlorophyta (84.1 5%) around Solanum nigrum and diatoms (53.3%) around Langonychium farctum. On the other hand, the number of total algal species in the study sites ranged between 2 and 1 6 species for Hyoscyamus muticus and Langonychium farctum, respectively. No species belong to chlorophyta and bacillariophyta around the root of Hyoscyamus muticus, Calendula micrantha and Ambrosia martema plants. The only one species encountered high occurrence remark was Pseudoanabaena papilloterminat (Cyanophyta). Treatments of Nostoc carneum with various soaked root extracts of Ambrosia maritima and Hoscyamus muticus caused enhancement of the growth, especially with high concentration of the extract (5%).

The present study examines the possibility of increasing the levels of some bioactive compounds (a-carotene, phycopiliprotein and total lipids) in Spirulina sp. isolated from Wadi El Natron lake (Egypt) and cultivated in modified Zarrouk's medium under standard growth condition and abiotic stress including change in culturing condition as (pH, temperature, light intensity), nutrient limitation (-N, -P, -S) and salinity. The yield production of a-carotene was enhanced with 0.9M NaCl, phosphorus deficiency and at pH 6. Total lipids were also enhanced in all conditions under tested especially with 0.9M NaCl, light intensity 1 4.52 Xmol photon.m-2.s-1 . Phycobiliproteins fractions (phycocyanin, allophycocyanine and phycoerethrine) were elevated with 0.3, 0.6M NaCl as well as phosphorus, nitrogen and sulphur deficiency. Antioxidant enzymatic activities of Spirulina sp. were elevated with all studied abiotic stress factor.

The present study examines the possibility of increasing the levels of some bioactive compounds (a-carotene, phycopiliprotein and total lipids) in Spirulina sp. isolated from Wadi El Natron lake (Egypt) and cultivated in modified Zarrouk's medium under standard growth condition and abiotic stress including change in culturing condition as (pH, temperature, light intensity), nutrient limitation (-N, -P, -S) and salinity. The yield production of a-carotene was enhanced with 0.9M NaCl, phosphorus deficiency and at pH 6. Total lipids were also enhanced in all conditions under tested especially with 0.9M NaCl, light intensity 1 4.52 Xmol photon.m-2.s-1 . Phycobiliproteins fractions (phycocyanin, allophycocyanine and phycoerethrine) were elevated with 0.3, 0.6M NaCl as well as phosphorus, nitrogen and sulphur deficiency. Antioxidant enzymatic activities of Spirulina sp. were elevated with all studied abiotic stress factor.

The present study examines the possibility of increasing the levels of some bioactive compounds (a-carotene, phycopiliprotein and total lipids) in Spirulina sp. isolated from Wadi El Natron lake (Egypt) and cultivated in modified Zarrouk's medium under standard growth condition and abiotic stress including change in culturing condition as (pH, temperature, light intensity), nutrient limitation (-N, -P, -S) and salinity. The yield production of a-carotene was enhanced with 0.9M NaCl, phosphorus deficiency and at pH 6. Total lipids were also enhanced in all conditions under tested especially with 0.9M NaCl, light intensity 1 4.52 Xmol photon.m-2.s-1 . Phycobiliproteins fractions (phycocyanin, allophycocyanine and phycoerethrine) were elevated with 0.3, 0.6M NaCl as well as phosphorus, nitrogen and sulphur deficiency. Antioxidant enzymatic activities of Spirulina sp. were elevated with all studied abiotic stress factor.