Strain and Plastic Composite Support (PCS) Selection for Vitamin K (Menaquinone-7) Production in Biofilm Reactors

Abstract. Menaquinone-7 (MK-7), a subtype of vitamin K, has received a significant attention due to its effect on improving bone and cardiovascular health. Current fermentation strategies, which involve static fermentation without aeration or agitation, are associated with low productivity and scale-up issues and hardly justify the commercial production needs of this vitamin. Previous studies indicate that static fermentation is associated with pellicle and biofilm formations, which are critical for MK-7 secretion while posing significant operational issues. Therefore, the present study is undertaken to evaluate the possibility of using a biofilm reactor as a new strategy for MK-7 fermentation. Bacillus species namely Bacillus subtilis natto, Bacillus licheniformis, and Bacillus amyloliquifaciens as well as plastic composite supports (PCS) were investigated in terms of MK-7 production and biofilm formation. Results show the possibility of using a biofilm reactor for MK-7 biosynthesis. Bacillus subtilis natto and soybean flour yeast extract PCS (SFY) in glucose medium were found as the most potent combination for production of MK-7 as high as 35.5 mg/L.