Development of a novel pilot-scale tray bioreactor for solid-state fermentation aiming at process intensification

Abstract

Solid-State Fermentation (SSF) processes have high contamination and low productivity rates, since it involves batch processes with multiple manual stages. In order to reduce handling in SSF processes, this research developed a pilot-scale tray bioreactor that enables process intensification by combining upstream operations and fermentation in a single equipment. Thus, a novel tray bioreactor was developed with an atomization system of spore suspension, nutrient solution, and cooling water above the fermentative medium. It also incorporates a sterilization system using steam. In order to validate the bioreactor, two case studies were conducted. In the first case study, the fungus Metarhizium anisopliae was cultivated on three types of agro-industrial residues. The conidia/mL obtained using the mixture of wheat bran and broken rice was (16.7±0.46)×108, which is statistically higher (α=0.05) than the fungus production of (8.59±1.60)×108 cultivated on the control (Type I Rice). In the second case study, lipases from M. anisopliae were produced on agro-industrial residues. The enzymatic activity average was 5.64±0.45U/mL based on 36 fermentations. The results have shown that the new tray bioreactor can produce the fungus and lipases in greater quantities than other systems reported in literature, while reducing handling, energy, costs, and process time.