Economical production of vitamin K2 using crude glycerol from the by-product of biodiesel

Abstract

Industrial waste, such as crude glycerol, was used for vitamin K₂ by B. subtilis Z-15. Crude glycerol could be used instead of pure glycerin for vitamin K₂ production. The combination of soybean peptone and yeast extract was more conducive to the synthesis of vitamin K₂. The optimal composition of medium was obtained by response surface methodology. The results indicated that the optimal medium was as follows: 6.3% crude glycerol, 3.0% soybean peptone concentration and 5.1 g/L yeast extract. Under the optimal culture medium, vitamin K₂ production was increased to 45.11 ± 0.62 mg/L. The fermentor test further proved that the use of crude glycerol affected neither the synthesis of vitamin K₂ nor the growth of B. subtilis. These investigations could lay a foundation for reducing the pollution of crude glycerol, exploring a late model for vitamin K₂ cleaner production.