Effect of metal support and different carbon sources on CLA production using Lactobacillus plantarum

In this study, conjugated linoleic acid (CLA) was produced using Lactobacillus plantarum in biofilm reactors with different carbon sources (glucose, lactose or a combination of glucose-lactose (1:1)). Presence of metal support in reactors resulted in high biofilm formation by L. plantarum. Two isomers of CLA were identified in fermentation broths; a) cis-9, trans-11 C18:2 (CLA1) as the predominant isomer (22.12 μg/mL), and b) trans-9, trans-11 C18:2 (CLA2) (14.96 μg/mL). Further analyses showed that depending on the carbon source used for the growth of L. plantarum in biofilm reactors, the amount of biomass and CLA production changed. Results indicated that by using combined lactose-glucose (1:1) as carbon source in biofilm reactors, the highest biomass (3.66 g/L) and the maximum concentration of CLA (37.08 μg/mL) were obtained. Scanning electron microscopy of the support used within the fermentation showed that the highest biofilm accumulation on the metal support was associated with the broth supplemented with combined glucose-lactose. This study suggested a high capacity of immobilized L. plantarum on the metal support to produce high quantity of CLA isomers with the use of combined glucose-lactose.