MK in SmF was extracted from the culture broth together with its biomass (10 mL) with the addition of 70 % ethanol to 50 mL. In SSF, the MK was extracted from 0.5 g of dry solid cultures which were ground to powder (80 mesh) with 50 mL of 70 % ethanol. Extraction of samples from both SmF and SSF was carried out in 55 _C water bath for 1 h with intermittent shaking. The extract was filtered through 0.45 lm membrane and then analyzed by high performance liquid chromatography (Model Agilent 1200, USA), according to our previously described method.