Study of Optimum growth conditions and nutrition value of the two endemic microalgae, Haematococcus sp. and Desmodesmus cunaetus, in different culture media

Identification of the optimum culture conditions of unicellular algae in different culture media is one of the most important steps required for industrial cultivation requirements of algae. Two microalgae Haematococcus sp. and Desmodesmus cunaetus, as valuable microalgae families, were newly isolated from inland of West Azerbaijan Province. In order to determine the best medium for these algae five different media (BM, RM, OHM, BBM and CHU) were studied for their growth rate and fatty acid content in a period of 12 days. To determine the growth rate, cell density and doubling time, counted daily done by Neubauer haemocytometer. The cells were harvested in the stationary phase to determine the fatty acid and protein content. The results of present study revealed the highest density (18.9 ± 0.68 ×105 cell.mL-1) and maximum specific growth rate (0.16 ± 0.06 day-1) in the microalgae Haematococcus sp. while using in OHM medium. The current study also depicted the maximum cell density (21.31 ± 1.11×105 cell.mL-1) and growth rate (0.17±0.06 day-1) of D.cunaetus in RM medium. In addition, the maximum content of PUFA (polyunsaturated fatty acid) and n-3/n-6 of both microalgae was found in the culture medium of BBM.Discussion and On the basis of our experimental results, we conclude that no clear parallel could be established between good nutritional characteristics of the biomass and mechanism of algae growth hence further research is demanded in this area. However, a compromise between the nutritional properties and growth of both microalgae could be achieved by the use of BBM medium, which provides good fatty-acid composition and adequate protein content as well as relatively high specific growth rate.