Commercial Microalgae Culture in Inorganic Fertilizer Media

Algal biomass production using relatively and locally available NPK formulated media has been identified as a key factor in commercial algal biomass production. The suitability of agricultural fertilizer as a growth medium for commercial algae cultivation was assessed using NPK 15:15:15, NPK 20:20:20 and composite medium of NPK 15:15:15+ BG11, while BG11 was used as a control medium. Microalgae Chlorella species was cultivated in these NPK formulated media at ambient temperature under solar irradiation for a period of 15 days. The cell biomass was determined by the optical density at 660nm, cell dry weight and total chlorophyll content were also determined. The maximum value for cell biomass of 0.356 mg/L, total chlorophyll content of 0.0.493 mg/ml and cell dry weight of 0.0185 mg/L achieved in the composite medium was closer to the values of 0.389 mg/L, 0.531 mg/ml and 0.2121 mg/L for cell biomass concentration, total chlorophyll content and dry cell weight respectively for BG11 medium. Although NPK 15:15:15 and NPK 20:20:20 media achieved lower values for cell biomass, total chlorophyll, and cell dry weight, there is no significant statistical difference between the media. This study suggests that inorganic fertilizer can be a relatively cost-effective and locally available substitute for commercial algae biomass production.