Enhancement of biomass production and productivity of Arthrospira platensis GMPA7 using response surface monitoring methodology and turbidostatic cultivation strategy

The cyanobacterium Arthrospira platensis plays a unique role in the food industry and is a promising and valuable natural source of bioactive compounds. The culture density of A. platensis should be further increased to improve biomass production and productivity, resulting in high conversion efficiency and reducing the cost of production. In this work we utilize a series of methods to increase the biomass yield from 2.26 to 21.57 g L−1. By screening live algae filaments and removing dead algal mass via filtration before cultivation, the biomass production increased from 2.26 to 2.77 g L−1. Using response surface monitoring methodology to optimize the light intensity and initial culture density further improved biomass production to 5.97 g L−1. We also evaluated the feasibility of fed-batch and turbidostatic cultivation for enhancing biomass production of A. platensis GMPA7. The results showed that fed-batch cultivation can increase the biomass production to 15.56 g L−1. Finally, turbidostatic cultivation can further improve the biomass production to 21.57 g L−1, which is a more than eightfold increase compared to the starting culture. Therefore, the turbidostatic cultivation strategy can be further exploited for large-scale and long-term cultivation.