Anaerobic Fermentation with Lactobacillus acidophilus LA-3 for the Production of Lactic Acid and Protein-Rich Biomass from Waste of the Non-centrifugal Cane Sugar Agroindustry

In the present study, anaerobic fermentation with Lactobacillus acidophilus LA-3 was evaluated as an alternative for the use of waste from the non-centrifugal cane sugar agroindustry, sugarcane scum (SCS) and molding washing water (MWW), for its valorization through the production of biomass rich in protein (PB) and lactic acid (LA). Fermentation tests of solutions of 50, 100 and 150 g SCS L⁻¹ were carried out. The highest percentage of carbohydrates consumed (CC) and biomass yield were observed in the fermentation of the 100 g SCS L⁻¹ solution, with 95.28% CC and a biomass yield of 0.53 g PB g CC⁻¹. The highest LA production was detected in the test with the 150 g SCS L⁻¹ solution, with a maximum production of 9.56 g LA L⁻¹. The kinetic parameters of substrate consumption were obtained with the Gompertz model of four parameters, where the solutions of 50 and 100 g SCS L⁻¹ presented the highest values, 0.9408 and 1.1070 g L⁻¹, respectively. The above results were supplemented with an economic analysis for the production of LA, which showed that there are acceptable values for economic yield (0.67 and 0.68 $ of LA $ of nutrient⁻¹) during the fermentation of these same solutions. In this way, it is demonstrated that the anaerobic fermentation process is a viable alternative for the utilization of waste generated in the non-centrifugal cane sugar agroindustry, allowing its valorization through the production of PB and LA.