Production of menaquinone – 7 by Bacillus cereus KMV07: a strain isolated from fermented Glycine max

Abstract

Menaquinone-7 has gained popularity due to its beneficial effects on health, there is an increased demand for its production among various sectors. In this study, vitamin MK-7 was produced from Bacillus cereus isolated from fermented Glycine max (soy bean). This study includes isolation, screening of bacteria capable of producing Menaquinone – 7 [MK-7] and production of MK-7 was optimized using one factor optimization method. Different food samples including both fermented and non-fermented ones were collected from Vellore district and a total of 30 strains were isolated for the study. All of these were subjected for the screening of MK-7 using HPLC. This quantitative analysis determined that the bacterial strain KMV07, which was isolated from fermented soybean was identified as the producer of MK-7. Among the isolated strains, KMV07 showed a significant potency in MK-7 production with a yield of 16.74 ± 1.21 mg/L. Based on the morphology, biochemical and molecular identification, the strain was identified as Bacillus cereus (KMV07). The objective of the research was to increase the production of MK-7 by the strain KMV07. Using different parameters, one factor optimization was done in-order to increase the production. This study indicated that maximum production was achieved under culture conditions when maltose and tryptone were used as carbon and nitrogen sources, with a pH of 8, an inoculum size of 3 mL (8.25 × 10⁶ CFU/mL) and an incubation time of 120th h. This study implies that Bacillus cereus (KMV07) isolated from Glycine max could be a suitable candidate for the increased production of MK-7.