Effects of temperature and pH on biochemicals content of microalgae Monoraphidium sp.

The production of secondary metabolites varies under the different environmental conditions. The aim of this study was to investigate the effects of pH and temperature on the content of antioxidant compounds in a species of microscopic algae. First, the microalgal strain Monoraphidium sp. was cultured under the different temperature and pH treatments. The biochemical assays were then performed on the compounds such as photosynthetic pigments, phenolic compounds, and total flavonoids. The total antioxidant activity was evaluated by FRAP and DPPH methods. The results of this study showed that the microalgae Monoraphidium sp. had the maximum growth and high content of antioxidant compounds at the acidic pH and temperature 28°C. The results indicated that the optimal conditions can be achieved for the high production of antioxidant compounds in microalgae by changing the environmental factors, which can be used in the pharmaceutical, medical, and production of nutritional supplements industries.