Bioconversion kinetics of conjugated linoleic acid by Lactobacillus plantarum ZS2058

Abstract:

Abstract: [Objective] Studying the kinetics of conjugated linoleic acid (CLA) bioconversion by Lactobacillus plantarum ZS2058. [Methods] We investigated the effects of the substrate concentration, cell mass, reaction pH and temperature on the reaction rate of producing CLA by L. plantarum ZS2058, and established the equations of reaction rate at the initial response stage under different substrate concentrations by double-reciprocal plot and Hanes-Woolf plot method. [Results] The results showed that there existed in a marked substrate inhibition effect, and the early reaction rate of producing c9, t11-CLA reached the maximum of 15.99 μg/(mL?h) when linoleic acid concentration was 0.4 mg/mL. The early reaction rate ascended with the cell mass increasing, and when the cell mass was at 5×1010 cfu/mL, the response rate close to the maximum. The optimum pH and temperature of bioconversion of CLA were 6.5 and 40℃ respectively. Michaelis constant was obtained by double-reciprocal plot and Hanes-Woolf plot method, the reaction rate equation followed the classic Michaelis-Mentent equation at the low substrate concentration, while there existed in a marked substrate inhibition effect at the high substrate concentration. [Conclusion] Through exploring the various factors of CLA bioconversion by L. plantarum ZS2058, we established the reaction rate equations of the initial response stage under different substrate concentrations, and got the optimal reaction conditions. These results will contribute to the CLA production and its physiological functions research.