This study investigates the potential of using untreated citrus waste as a sustainable feedstock for the one-step production of L-lactic acid (L-LA) through microbial fermentation. The strain *Weizmannia coagulans* MA-13, known for its probiotic and prebiotic properties, was employed in conjunction with a thermophilic enzymatic cocktail (Cellie CTec2) to enhance biomass degradation. The results showed that the combination of MA-13 and the enzymatic cocktail increased biomass degradation by up to 62%. Batch and fed-batch fermentation experiments demonstrated the complete conversion of glucose into L-LA, achieving a concentration of up to 44.8 g/L. The study highlights the potential of MA-13 as a microbial cell factory for the sustainable production of L-LA from citrus waste, combining cost-effective saccharification with efficient fermentative performance. The findings also emphasize the eco-friendly and sustainable valorization of agricultural waste streams.This study investigates the potential of using untreated citrus waste as a sustainable feedstock for the one-step production of L-lactic acid (L-LA) through microbial fermentation. The strain *Weizmannia coagulans* MA-13, known for its probiotic and prebiotic properties, was employed in conjunction with a thermophilic enzymatic cocktail (Cellie CTec2) to enhance biomass degradation. The results showed that the combination of MA-13 and the enzymatic cocktail increased biomass degradation by up to 62%. Batch and fed-batch fermentation experiments demonstrated the complete conversion of glucose into L-LA, achieving a concentration of up to 44.8 g/L. The study highlights the potential of MA-13 as a microbial cell factory for the sustainable production of L-LA from citrus waste, combining cost-effective saccharification with efficient fermentative performance. The findings also emphasize the eco-friendly and sustainable valorization of agricultural waste streams.