Integration of 2,3-butanediol production and extraction of active components from Chinese herbs by Bacillus licheniformis and evaluation of fermentation products in vitro

The aim of this work was to develop an integrated process of 2,3-butanediol production and extraction of active components from Chinese herbs via fermentation, and evaluate their potential as cosmetic ingredients in vitro. A GRAS strain DL2–2 of Bacillus licheniformis was isolated and the fermentation medium was optimized using the ingredients that could be used in cosmetics. Four types of Chinese herbs were added solely or in combination into the fermentation medium to perform 2,3-butanediol production and active components extraction simultaneously. The release of polysaccharides and flavonoids was promoted, and the antioxidant, whitening and antibacterial abilities were improved. The highest antioxidant and antibacterial activity was obtained from the ferment filtrate of Dendrobium devonianum and Gastrodia elata f. glauca , resulting from the highest contents of flavonoids (0.44 g/L) and polyphenols (0.31 g/L), and 42.2 g/L 2,3-butanediol was also produced. The highest polysaccharide concentration was obtained from the ferment filtrate containing Polygonatum kingianum , which exhibited the highest inhibitory effect on tyrosinase (65 %), similar to that of 1 g/L arbutin. Therefore, the filtrate of 2,3-butanediol-Chinese herbal fermentation broth is promising as an ingredient in the production of natural high-value cosmetics.