A Critical Evaluation of Recent Studies on Packed-Bed Bioreactors for Solid-State Fermentation

Packed-bed bioreactors are often used for aerobic solid-state fermentation, since the forced aeration supplies O2 and removes metabolic heat from bed. Motivated by potential applications in biorefineries, we review studies conducted on packed-bed over last decade, evaluating insights these provide into how large-scale packed beds should be designed operated. Many have low superficial air velocities suffer preferential airflow, such that parts of bed not properly aerated. Moreover, some proposed ineffective strategies, as reversing direction airflow or introducing through perforated pipes within Additionally, many narrow water-jacketed bioreactors, but do reflect removal wide beds, which side walls makes a minor contribution. Finally, conclude that, although attention has been given to characterizing porosities, water sorption isotherms volumetric mass transfer coefficients substrate this work needs extended cover wider range solid substrates, done characterize properties change due microbial growth.