Optimization and kinetic modeling of media composition for hyaluronic acid production from carob extract with Streptococcus zooepidemicus.

Abstract

Hyaluronic acid (HA), a mucopolysaccharide belonging to the glycosaminoglycan family, consists of repeating disaccharide units and has been used directly or indirectly in numerous human health practices. This study focused on evaluating carob pods for microbial HA production and kinetic modeling of HA fermentation. Therefore, the optimal medium composition was determined using Plackett-Burman Design (PBD) for HA production from carob extract with Streptococcus zooepidemicus. Maximum HA production of shake flask fermentation was 2.6g/L (1.25 × 106) in the optimum medium, comprising 10°Bx of carob pods extract, 0.5g/L of MgSO4.7H2O, 10.0g/L of casein, 2.5g/L of KH2PO4, 2.0g/L of NaCl, 1.5g/L of K2HPO4, 0.002g/L of FeSO4 and 10.0g/L of beef extract. In the continuation of the study, the fermentation performed with the optimal medium composition was modeled using three different models including the logistic model for biomass production, the Luedeking-Piret model for HA production, and the modified Luedeking-Piret model for substrate consumption. Based on the results, the experimental HA production data agreed with the Luedeking-Piret model with an R2 of 0.989. Since the α value was 63-fold higher than the value of β, the HA production is growth-associated. Consequently, carob extract can be evaluated as a promising carbon source for producing HA.