Influence of site-directed mutagenesis of UbiA, overexpression of dxr, menA and ubiE, and supplementation with precursors on menaquinone production in Elizabethkingia meningoseptica

•UQ pathway weakening increased the MK content by 180% than that of the WT.•Precursor supplementation increased the MK content of the WT strain by 235%.•Three strategies combined increased MK content more than 11 times.