Study on Fermentation Kinetics and Optimization of Feeding Strategy for Menaquinone-7 (Vitamin K2) Production by Bacillus Subtilis

Abstract

Menaquinone-7 (MK-7), a biologically active form of vitamin K2,plays a critical role in preventing osteoporosis and cardiovascular calcification, making it a valuable component in dietary supplements. This study investigated the fermentation process of Bacillus subtilis BS018, which produces MK-7, by integrating fermentation kinetics. Based on this, a feeding strategy was developed and validated at the 5 L bioreactor, and fermentation experiments were conducted in a 1 T bioreactor. The selected fermentation kinetic model effectively described the fermentation process of BS018, with kinetic parameter analysis indicating that MK-7 is a non-growth-associated product. In the 5 L bioreactor, the MK-7 yield of the batch supplemented with 10g/L (grams of added glycerol per volume of fermentation broth) glycerol at 24 hours of fermentation was 1.72 times that of the non-fed batch. At the 1-ton bioreactor, the MK-7 yield reached 72.65 mg/L