High production of erythritol from Candida sorbosivorans SSE-24 and its inhibitory effect on biofilm formation of Streptococcus mutans.

Amongst different isolates screened for erythritol production, isolate no. SSE-24 was found to be the best erythritol producer and identified as Candida sorbosivorans SSE-24. Statistical optimization was used to determine the optimum level of the significant variables for maximum erythritol production. The interactive effects of glucose, inoculum level and yeast extract were determined to be significant. The optimum medium composition for erythritol production was 160 g/L glucose, 12 g/L yeast extract, 10% inoculum level and 0.35 g/L FeSO4⋅7H2O. The production of erythritol was successfully scaled up to a 30 L level, where 60.20 g/L of erythritol was produced, with a yield of 0.38 g/g. The fermentation broth was purified by activated charcoal followed by vacuum concentration, ion exchange chromatography and crystallization. Purity of erythritol was further determined by NMR. Significant inhibitory effect of erythritol on growth (>78%) and biofilm formation (40.2%) of Streptococcus mutans enhances the importance of this study.