摘要：SummaryHaematococcus pluvialis, the richest bioresource for natural astaxanthin, encounters a challenge of achieving high growth rate when it comes to mass biomass production. Based on the substrate consumption model and Redfield ratio, rapid algae growth benefits from a proper carbon supply. However, the conventional cultivation schemes with limited carbon dioxide (CO2) supply and inefficient carbon mass transfer could have constrained the carbon capture and growing ability ofH. pluvialis. We hypothesize that optimalH. pluvialisgrowth improvement may be achieved by efficient CO2supply. Here, in this study, we first identified the carbon consumption ofH. pluvialisduring exponential growth. Then, a novel microbubble-driven photobioreactor (MDPBR) was designed to satisfy the carbon demand. The novel microbubble photobioreactor improves the CO2supply by reducing bubble size, significantly elevating the CO2mass transfer. With only 0.05 L min−1of gas flow rate, higher cell growth rate (0.49 d−1) has been achieved in MDPBR.Graphical abstractDisplay OmittedHighlights•The CO2mass transfer demand for optimalH. pluvialisgrowth is identified•The impact of key parameters on mass transfer are discussed•Reducing bubble size has pronounced effect on CO2mass transfer•Microbubble photobioreactor demonstrates a high biomass ofH. pluvialisBiological sciences; Biotechnology; Microbial biotechnology
