LAUSR

Valorization of cassava fibrous waste by lactic acid bacteria (LAB) into D-lactic acid (DLA) may assuage the massive supply chain for the synthesis of alternative bioplastics such as PLA. This investigation aims at developing a potential LAB cell factory say Lactobacillus delbrueckii, to synthesize DLA in a cost-effective biological route utilizing second-generation agricultural feedstock. Along with CFWEH (20 g/L), other complex nitrogen sources and yeast extract (YE)-based medium yielded 17.75 g/L of DLA. Further optimization based on one factor at a time approach (OFAT), YE at 5 g/L was found to be optimal for DLA production. At different initial CFWEH concentrations from 20 to 120 g/L, kinetic modeling of biomass and DLA formation and CFWEH consumption was carried out by weighted-average least square method. Predicted parameters show that the inhibitory concentration for substrate was above 99 g/L, also inhibition due to DLA synthesis occurred as high as 59 g/L for 120 g/L substrate loading. This research finding offers the knowledge of kinetic parameters, its transformation into operational parameters, which would be helpful for sustainable synthesis of DLA.