Abstract: An air-stirred tank reactor (ASTR) and methods of use thereof are described herein. The ASTR is equipped with an impeller or set of impellers that mechanically mixes a liquid culture, as well as sparges gas into the liquid medium. The impeller can further have lighting sources that can illuminate the liquid culture. Unlike conventional bioreactors, the ASTR provides superior liquid mixing, efficient gas mass transfer, and a low-shear culture environment through appropriate impeller rotational speed and sparging rate.