Furan Inhibitor Effects on Native Lactic Acid Bacteria from Maule Region: Growth Kinetics and Lactic Acid Production from Agroindustrial Waste

Abstract

Native Lactic Acid Bacteria (LAB) isolated from fruits and vegetables in Chile’s Maule Region were identified as Lactiplantibacillus plantarum and L. pentosus. Their growth and lactic acid production were evaluated under furan inhibitor stress (furfural and 5-methylfurfural (5-MF)) relevant to agroindustrial waste valorization. In fruit hydrolysates containing natural furans (11–57 mg/L), LAB grew similarly to inhibitor-free controls and produced 17–25 g/L lactic acid. Under controlled conditions, furfural at 12 g/L reduced bacterial growth by over 80% and decreased lactic acid production to only 2 g/L. In contrast, 5-MF at the same concentration allowed substantially higher tolerance, with up to 7 g/L lactic acid. Benchmarked directly against the commercial reference strain Lactiplantibacillus plantarum PL8014 under identical conditions, the native isolate B1 matched or exceeded PL8014’s lactic acid output in most furfural and 5-MF concentrations tested, including the two most severe 5-MF conditions. Logistic growth and Luedeking–Piret models accurately described both bacterial growth dynamics and lactic acid production kinetics under all inhibitory conditions (R2 > 0.96). Inhibitor concentration proved more critical than inhibitor type, although furfural consistently showed stronger potency. These findings confirm the biotechnological potential of native Maule LAB and provide quantitative kinetic parameters for optimizing lactic acid production from lignocellulosic waste, supporting circular economy strategies.