Statistical optimization of medium with response surface methodology for biomass production of a local Iranian microalgae Picochlorum sp. RCC486

Microalgae biomass production and optimization is necessary to overcome food security problems and address environmental topic as well as high-value compounds production. In this investigation the influence of three culture media (BBM, BG-11 and Guillard f/2) on the growth and biomass production of the Picochlorum sp. RCC486 microalgae was evaluated. One- way ANOVA with Tukey’s HSD and Fisher’s LSD tests were used to test the effect of different culture media on optical density. Then the maximum optical density and biomass production by Picochlorum sp. RCC486 was evaluated using response surface methodology. A historical data of response surface methodology was used to find the optimum response, which yields the highest biomass production. Microalgal growth in Guillard f/2 medium reached highest cell count in the considered time period and the microalgae presented highest biomass production in comparison with other two culture media (BBM and BG-11). Additionally, biomass productivity(58 mg L-1d-1 ), specific growth rate (0.681d-1), dry weight (1.516 g L-1) and cell density(52.9 ×106 cells mL-1) were highest in comparison with other two culture media. The predicted optical density and biomass production using historical data design were close to their experimental values corresponding to 1.50313 and 1.976gL-1 respectively. while the concentrations of nitrogen source and phosphorus source were achieved in concentrations of 1345.55 mg L−1, 6.983 mg L−1 respectively. Under the optimum condition, the biomass yield was1.961 gL-1 which is 0.76% less than the predicted value. Also the study reported that the biomass production of Picochlorum sp. RCC486 improved from 1.516 g L-1 in defined Guillard f/2 medium to 1.961 g L-1 in modified Guillard f/2 medium resulting 22.69% increase. Thus, Picochlorum sp. RCC486 biomass content could be enhanced by optimizing nitrogen and phosphorus concentrations.