Optimizing the Growth of Haematococcus Pluvialis Based on a Novel Microbubble-Driven Photobioreactor

Haematococcus pluvialis (H. pluvialis), the richest bioresource for natural astaxanthin, encounters a challenge of achieving high growth rate when it comes to mass biomass production.  Base on substrate consumption model and Redfield ratio, rapid algae growth benefits from a proper carbon supply. However, the conventional cultivation schemes with limited CO2 supply and inefficient carbon mass transfer may restrict the carbon capture and growing ability of H. pluvialis. We hypothesize that optimal H. pluvialis growth improvement may be achieved by efficient CO2 supply. In this study, we first identified the carbon consumption of H. pluvialis during exponential growth. Then, a novel microbubble-driven photobioreactor (MDPBR) was designed to satisfy the carbon demand. The novel microbubble photobioreactor improve the CO 2 supply by reducing bubble size, then the CO2 mass transfer significantly elevated. With only 20% of gas flow rate, higher cell growth rate (0.49 d-1) has been achieved in MDPBR.