Comparative evaluation of glucosamine derivatives for enhanced microbial hyaluronic acid production by Streptococcus...

The extraction of hyaluronic acid (HA) from animal tissues such as rooster combs or bovine vitreous humor is limited by complex purification steps and contamination risks. Microbial fermentation has therefore become a sustainable alternative for HA production. This study aimed to optimize the temperature and pH conditions for Streptococcus pyogenes using the Taguchi method and to investigate the effects of three glucosamine derivatives D-(+)-glucosamine hydrochloride, N-acetyl-D-glucosamine, and D-glucosamine 3-sulfate on HA synthesis by Streptococcus pyogenes and Streptococcus zooepidemicus. The optimal temperature and pH conditions for S. pyogenes HA production were identified as 32 °C and pH 8.0. Among the glucosamine derivatives tested, supplementation with 1.3 g N-acetyl-D-glucosamine and 2 g D-glucosamine 3-sulfate significantly increased HA production in S. zooepidemicus, reaching 1018.9 mg/L and 739.0 mg/L, respectively, whereas glucosamine hydrochloride showed no significant effect. In contrast, the highest mean HA concentrations in S. pyogenes were 773.7 mg/L with 0.8 g D-(+)-glucosamine hydrochloride and 540.5 mg/L with 2 g D-glucosamine 3-sulfate, although these differences were not statistically significant. No significant differences were observed among the tested concentrations of N-acetyl-D-glucosamine. These results demonstrate that the type and dosage of glucosamine precursors exert strain-specific effects on HA biosynthesis. This work provides a comparative analysis of glucosamine derivatives in Streptococcus species, offering new insights into microbial HA production strategies.