Advances in Enhanced Menaquinone-7 Production From Bacillus subtilis

Abstract

The production of nutraceutical compounds through biosynthetic approaches has received considerable attention in recent years. For example, Menaquinone-7 (MK-7), a sub-type of Vitamin K2, biosynthesized from Bacillus subtilis (B. subtilis), proved to be more efficiently produced than the conventional chemical synthesis techniques. This is possible due to the development of B. subtilis as a chassis cell during the biosynthesis stages. Hence, it is imperative to provide insights on the B. subtilis membrane permeability modifications, biofilm reactors, and fermentation optimization as advanced techniques relevant to MK-7 production. Although the traditional gene-editing method of homologous recombination improves the biosynthetic pathway, CRISPR-Cas9 could potentially resolve the drawbacks of traditional genome editing techniques. For these reasons, future studies should explore the applications of CRISPRi (CRISPR interference) and CRISPRa (CRISPR activation) system gene-editing tools in the MK-7 anabolism pathway.

Recent advances in the metabolic pathways and microbial production of coenzyme Q

“…for the production of patchoulol (Henke et al 2018 ) and bisabolene (Rodrigues and Lindberg 2021 ), respectively. Overexpressing dxs , dxr and idi has improved production of isoprene in E. coli (Lv et al 2013 ) and menaquinone-7 in B. subtilis (Ma et al 2019 ; Liao et al 2021 ). Volke et al showed by metabolic control analysis in E. coli that indeed Dxs and Idi constitute major flux controlling steps and that upon dxs overexpression, 2-C-methyl- d -erythritol 2,4-cyclodiphosphate accumulates intracellularly, while it is also exported outside the cells rather than being reduced to 4-hydroxy-3-methylbut-2-enyl diphosphate.…”

Culturomics of Bacteria from Radon-Saturated Water of the World’s Oldest Radium Mine

“…The greater resistance to oxidative stress of the isolates studied here might be also ascribed to several other causes. For example, the isolates of the genus Bacillus intrinsically contain multiple copies of the menaquinone MK-7 ( 96 ), which are involved in the respiratory electron transport chain, and their reduced forms protect the cellular membranes against oxidation ( 97 ). The diverse pigmentation of Brevundimonas (orange), Deinococcus (pink), Methylorubrum (purple), Kocuria (yellow), and Sphingopyxis (yellow-orange) strains, which is often the result of the presence of various carotenoids, can play a pivotal role in the response to radiation, as in other UV/α/β/γ radiation-resistant microorganisms such as red-pigmented Deinococcus radiodurans ( 87 , 98 ) and Rubrobacter radiotolerans ( 99 , 100 ), or orange-red-pigmented Brevundimonas sp.…”

Dual-sgRNA CRISPRa System for Enhanced MK-7 Production and Salmonella Infection Mitigation in Bacillus subtilis natto Applied to Caco-2 Cells

“…Specifically, in B. subtilis , the integration of the CRISPR/dCas9 system with CRISPR-assisted oligonucleotide annealing-based promoter shuffling (OAPS) for pathway optimization has led to a substantial enhancement in the production of B. subtilis amylase BLA, marked by an impressive 260-fold increase . This innovative system enables precise regulation of gene expression, essential for optimizing MK-7 biosynthesis . Utilizing the CRISPRa system, we engineered a dual-sgRNA CRISPRa system aimed at significantly enhancing MK-7 production in B. subtilis natto.…”