Simultaneous saccharification and citric acid production from paper wastewater pretreated banana pseudostem: Optimization of fermentation medium formulation and kinetic assessment

This study optimized the simultaneous saccharification and citric acid (CA) production from banana pseudostem (BP). Thereafter, kinetic assessment of Aspergillus brasiliensis growth and CA production were determined for the optimum conditions using fresh water (SSFoptimizedFW) or dairy wastewater (SSFDWW) and compared to Sabour-aud Dextrose Emmon's medium modified with BP (SSFSDEmodified). The optimized conditions gave a CA con-centration of 14.408 g/L. Kinetic assessment revealed the same maximum specific growth rates (mu(max)) (0.05 h(-1)) for all three bioprocesses, while the SSFSDEmodified process resulted in the highest maximum potential CA con-centration (P-m) (13.991 g/L) in comparison to the SSFDWW (P-m = 13.095 g/L) and SSFoptimizedFW (P-m = 12.967 g/ L) systems. Findings from this study facilitates the implementation of waste-based lignocellulosic bioprocesses that may eradicate the use of expensive pretreatment chemicals, fermentation medium constituents, and re-sources, in keeping with the water, energy and food nexus towards developing a circular bioeconomy.

Automated summary

This study optimized the simultaneous saccharification and citric acid production from banana pseudostem and compared different bioprocesses. The findings revealed that the use of modified medium with banana pseudostem resulted in the highest citric acid concentration. This study is important for promoting waste-based lignocellulosic bioprocesses.