Sustainable co-valorization of seawater pretreated banana pseudostem and dairy wastewater for bioethanol production

Abstract

Simultaneous saccharification and fermentation (SSF) of bioethanol production was optimized using banana pseudostem (BP) and dairy wastewater in this study. The kinetics of Saccharomyces cerevisiae BY4743 cell growth and bioethanol production under optimized medium conditions in dairy wastewater (DWW-SSF), pure water (PW-SSF), and a standard bioethanol fermentation medium modified with BP (mYPD-SSF) were comparatively investigated. The optimized DWW-SSF bioprocess resulted in a bioethanol concentration of 33.93 g/L which was 38% and 34% higher than the PW-SSF (24.67 g/L) and mYPD-SSF (25.28 g/L) processes. For the kinetic assessment, the highest maximum specific growth rate (µmax) of 0.60 h−1 was obtained for the PW-SSF process, followed by the DWW-SSF (0.34 h−1) and mYPD-SSF (0.27 h−1) bioprocesses. On the other hand, the DWW-SSF process led to the highest maximum potential ethanol concentration (Pm) of 28.68 g/L compared to 23.78 g/L and 23.09 g/L for the mYPD-SSF and PW-SSF processes respectively. This study highlights the potential of waste-based lignocellulosic bioethanol production through SSF bioprocesses, offering opportunities to reduce the reliance on costly fermentation medium components and finite water resources while simultaneously addressing industrial waste generation.