Culture of the hydrocarbon producing microalga Botryococcus braunii strain Showa: Optimal CO2, salinity, temperature, and irradiance conditions

► Optimal growth in the medium with 0.2-5% CO2 and in freshwater conditions. ► Maximum specific growth rate of 0.5 day−1 at 30 °C and 850 μmol photons m−2 s−1. ► The highest specific growth rate for B. braunii ever reported. ► Positive correlation of hydrocarbon contents (29-39%) with specific growth rate. ► Hydrocarbon productivity increased with increased specific growth rate.