Co-valorization of corn cobs and dairy wastewater for simultaneous saccharification and lactic acid production: Process optimization and kinetic assessment

This study optimized the co-valorization of corn cob wastes (CCW) and dairy wastewater for simultaneous saccharification and lactic acid (LA) production (sDWW-SSF). Subsequently, the kinetics of Lactobacillus plantarum growth and LA production was assessed using the optimized conditions under microaerophilic (sDWWSSFmicroaerophilic) and anaerobic (sDWW-SSFanaerobic) conditions, and thereafter compared to De Man, Rogosa and Sharpe (MRS) medium modified with pretreated CCW (mMRS-SSFmicroaerophilic). Optimized sDWW-SSF conditions produced maximum LA concentration and conversion of 11.15 +/- 0.42 g/L and 18.90 +/- 0.75%, respectively. Kinetic studies revealed that although the mMRS-SSFmicroaerophilic system obtained a higher maximum specific growth rate (mu max) and maximum potential LA concentration (Pm) compared to the wastewater-based bioprocesses, the data obtained for the latter were comparable when taking the resources and costs into consideration. These findings represent the potential to eliminate the use of valuable resources in lignocellulosic bioprocesses and provide insights on innovation towards driving a sustainable economy in line with the foodenergy-water nexus.

Automated summary

This study optimized the co-valorization of corn cob wastes and dairy wastewater for simultaneous saccharification and lactic acid production. The optimized conditions produced maximum lactic acid concentration and conversion. Kinetic studies revealed comparable results between wastewater-based bioprocess and modified medium, considering resources and costs.