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Summary
The current study deals with the biological responses to fresh water green algae Chlorella vulgaris, due to its exposure to some environmental effects, which included different concentrations of nutrients (nitrates and phosphates…
Summary
The current study deals with the biological responses to fresh water green algae Chlorella vulgaris, due to its exposure to some environmental effects, which included different concentrations of nutrients (nitrates and phosphates) and different concentrations Mgnisume (Mg) and Cadmium (Cd) elements , and the possibility of using these biological indicators as tools to measure the potential environmental impact.
Chlorella vulgaris was treated with three different concentrations of nitrates (10,15,20) mg/L and phosphate (0.1, 0.5, 1) mg/L also, different concentrations of magnesium (5, 10, 15) mg/L and cadmium (0.5, 1, 1.5) mg /L , and the experiments lasted for 14 days during which many physiological and biochemical parameters were measured in the algae under test.
This included growth curve, doubling time, photosynthesis pigments chlorophyll-a and carotenoids, as well as measuring variation in total protein and carbohydrates, then studying the effect of the previous factors on some enzymatic parameters such as Catalase, SOD, and ROS, and the results were recorded in (1 day, 7 days ,14 days).
A clear variation was observed in the growth curve and the doubling time for algae under test as a result of exposure to external influences, as the highest growth rate was recorded at concentration 1 mg / L of Cd after 14 days and reached to (1.495) while the lowest growth rate during the day 13 when algae was exposed to a concentration 10 mg / L of Mg , which is (0.0194).
As for the doubling time, it was the longest period during the day 13 and at a concentration of 10 mg / L when treated with Mg as it reached to (15.50) , while the longest doubling time was (0.201) during the14th day at a concentration of 1 mg / L When treated with Cd .
As for pigments of photosynthesis , the highest values of chlorophyll-a were recorded during the 14th day at a concentration of 20 mg / L when treated with nitrates , where it reached 0.438 μg/ml , while the lowest value of chlorophyll- a was recorded during the14th day at a concentration of 15 mg / L when treated with Mg , it reached 0.062 μg/ml and the highest values of carotenoids was 0.069 μg/ml during the 14th day with 1mg/L cadmium treatment, while the minimum was 0.002 μg/ml during the 14th day with 15mg/L concentration of magnesium treatment.
As for total protein , the highest values was 12.658 μg/L in the 14th day with 1.5 mg/L cadmium treatment, while the minimum was 1.772 μg/L during 14th day with 15mg/L concentration of magnesium treatment.
The maximum carbohydrate value was 1.162 μg/ml during 14th day with 1mg/L PO4 treatment, while the minimum was 0.293 μg/ml during 14th day with 5mg/L concentration of magnesium treatment.
The maximum SOD was 0.884 unit/L during 1st day with 15mg/L magnesium treatment, while the minimum was 0.073 unit/L during 14th day with 15mg/L concentration of magnesium treatment . The maximum ROS was 4.129 mM/ml during 14th day with 10mg/L NO3 treatment, while the minimum was 1.563 mM/ml during 7th day with 1mg/L concentration of PO4 treatment. Also, The maximum of CAT was 0.200 unit/ml during 7th day with 10mg/L magnesium treatment, while the minimum was 0.010 unit/ml during 14th day with 15mg/L concentration of magnesium treatment.
From the results , the algae Chlorella vulgaris has showed high efficiency to biorespond to an environmental impact assessment, and may be used in many cases, for example, as an environmental impact assessment tool or environmental health
