A pilot-scale airlift loop reactor (ALR) coupled with a low-shear swirl microbubble generator was first successfully designed and verified to improve mass transfer, mixing, and yeast production using straw. The hydrodynamics was explored in an air-straw-liquid system. With enhanced external circulation and microbubbles less than 150 μm, mass transfer was promoted by 11.5 times. The impacts of the low-shear microbubble generator on solid substrates and cell activity were also investigated. After long-term operation, the straw d