Comparative study of Spirulina sp. Growth under conditions of different concentrations of nitrogen and phosphorus

Spirulina sp. algae are able to produce various secondary materials, including polyhydroxybutyrate, which is a biopolymer and has various applications in industry and business. It can be also used as a degradable bio-material to replace some of the synthetic compounds that are low or non-degradable. Whenever this alga is exposed under stress conditions, the production of this substances is intensified. Determination of stress levels due to changes in the concentration of nitrogen and phosphorus were investigated by deficiency or high levels of these two elements in the algal growth medium. Based on the malondialdehyde index, N concentration changes could not induce stress meaningfully, but treatments resulting from different concentrations of phosphorus increased stress. Studies showed that none of the nitrogen and phosphorus concentrations used in this experiment can significantly reduce growth, and protein content of these treatments remained almost unchanged. The amount of phenol was significantly affected by the shortage or increased level of nitrogen and phosphorus content. Flavonoids and anthocyanins remained virtually unchanged against to deficiency and high level of nitrogen, but they have shown significant changes in content by changes in phosphorus concentrations. Therefore, although this level of limited variation of N concentrations cannot induce significant stress in the growth medium, phosphorous concentrations have more stress effects and can lead to an intensification of the processes which are involved in the production oSpirulina sp. algae are able to produce various secondary materials, including polyhydroxybutyrate, which is a biopolymer and has various applications in industry and business. It can be also used as a degradable bio-material to replace some of the synthetic compounds that are low or non-degradable. Whenever this alga is exposed under stress conditions, the production of this substances is intensified. Determination of stress levels due to changes in the concentration of nitrogen and phosphorus were investigated by deficiency or high levels of these two elements in the algal growth medium. Based on the malondialdehyde index, N concentration changes could not induce stress meaningfully, but treatments resulting from different concentrations of phosphorus increased stress. Studies showed that none of the nitrogen and phosphorus concentrations used in this experiment can significantly reduce growth, and protein content of these treatments remained almost unchanged. The amount of phenol was significantly affected by the shortage or increased level of nitrogen and phosphorus content. Flavonoids and anthocyanins remained virtually unchanged against to deficiency and high level of nitrogen, but they have shown significant changes in content by changes in phosphorus concentrations. Therefore, although this level of limited variation of N concentrations cannot induce significant stress in the growth medium, phosphorous concentrations have more stress effects and can lead to an intensification of the processes which are involved in the production of secondary compounds, including polyhydroxybutyrate.

Keywords:

Spirulina sp. , Stress , Nitrogen , Phosphorous