Fast and reliable voltammetric determination of menaquinone (vitamin K2) produced in vitro by Bacillus subtilis cultures

Abstract

Vitamin K2 (VK2) is one of two natural forms of vitamin K, necessary for the proper functioning of organisms. Currently, it is sourced from chemical synthesis, nonetheless, it is worth reaching out to its natural sources. The aim of the study was to devise a voltammetric procedure for the determination of vitamin K2 (VK2) produced by bacteria in order to find the strain that exhibits the highest efficiency of VK2 production. Bacillus subtilis, isolated from traditional Japanese food (Nattō), was chosen as a model strain. Employment of the Controlled Growth Mercury Drop Electrode (CGMDE) was crucial, as it is the only electrode that allows performing the measurement on the surface specifically renewed directly before, thus minimizing the influence of interferents.