Simultaneous Production of Vitamin K2 and Iturin A by Bacillus velezensis ND

Abstract

Abstract Bacillus velezensis is known to produce a diverse array of secondary metabolites, including the ability to synthesize lipopeptides such as iturin A, and additionally produce higher amounts of vitamin K2. Consequently, we sought to employ co-production fermentation to simultaneously generate vitamin K2 and iturin A. In order to significantly reduce fermentation costs and enhance substrate utilization efficiency, this article initially established a straightforward and effective product extraction method that enables the separate collection of vitamin K2 and iturin A from the fermentation broth. Simultaneously, the impacts of glycerol, soybean meal powder, yeast extract powder, and L-glutamic acid sodium, employed as carbon and nitrogen sources in the culture medium, on the co-production of vitamin K2 and iturin A were refined by optimizing factors such as culture temperature, initial pH and the concentrations of trace elements Na+ and K+, as well as additional additives L-glutamic acid sodium. It was discerned that glycerol, soybean meal powder, yeast extract powder, and L-glutamic acid sodium significantly influenced the concurrent production of vitamin K2 and iturin A. As a result, a novel process for the efficient co-production fermentation of vitamin K2 and iturin A was established, thereby enhancing the value-added aspect of the fermentation process. Furthermore, the implementation of a two-compartment biofilm reactor synergistically elevated the co-production efficiency. The yields of vitamin K2 and iturin A reached 46.88 mg/L and 5.58 g/L, respectively. This study provides a theoretical framework and practical implications for the integrated double-product fermentation process.