Strategic choices in bioprocessing of L(+)Lactic acid: Homo-fermentative Lactobacilli monocultures with novel agro-residue combination enhances economic production

Microbial fermentation of agro-industrial residues is gaining significant traction as a sustainable and economically viable approach in bioprocessing. This study explored lactic acid production from selected agro-industrial residues: pre-treated sugarcane waste, potato peel waste, or milk processing waste with alfalfa pellets using <i>Lactobacilli</i> strains of organic origin. Five homo-fermentative strains (VITJ1, VITJ2, VITJ3, VITJ4, and VITJ5) were assessed for compatibility and formed into 15 consortia. VITJ2 showed the highest individual production (147.1 ± 0.26 g/L at 48 h) in MRS media. The combination of sugarcane waste and alfalfa pellets yielded the highest crude lactic acid production (9.1 %) after 48 h, suggesting its potential as a cost-competitive fermentation medium for industrial-scale lactic acid production. This study contributes to the growing body of evidence supporting the valorization of agro-industrial residues as feedstock for bioprocesses. Furthermore, it presents the novel concept of utilizing <i>Lactobacilli</i> consortia for lactic acid production.