One of the major issues associated with industrial production of menaquinone-7 (MK-7) is the low fermentation yield. In this study, we investigated the effect of iron oxide nanoparticles coated with 3-aminopropyltriethoxysilane (IONs@APTES) on the production of MK-7 using B. subtilis (ATCC 6633). Decoration of B. subtilis cells with IONs@APTES significantly enhanced both MK-7 production and yield. An approximately two-fold increase in MK-7 production (41 mg/L) was observed in the presence of 500 µg/mL IONs@APTES, as compared to MK-7 production using untreated bacteria (22 mg/L). This paper, therefore, illustrates the immense biotechnological potential of IONs@APTES in increasing MK-7 concentration using B. subtilis, and its future role in bioprocess engineering.
Keywords: B. subtilis; IONs@APTES; MK–7; fermentation; immobilization.