Microfluidic perfusion bioreactor for optimization of microalgal lipid productivity

Nutrient deprivation in a batch process induces microbes to produce secondary metabolites while drastically constraining cellular growth. A microfluidic continuous perfusion system was designed and tested to culture microalgae, Chlamydomonas reinhardtii, under constant nutrient concentration slightly lower than normal condition. When cultured in 7.5%/7.5% of NH₄⁺/PO₄^2-, C. reinhardtii showed a 2.4-fold increase in TAG production with a 3.5-fold increase in biomass compared to level obtained under an only NH₄⁺ depleted condition. The microfluidic continuous perfusion bioreactor with steady continuous nutrient flow can be used to optimize conditions for enhancing secondary metabolite production and increasing microbial biomass.