Transcriptomic analysis of gene expression of menaquinone-7 in Bacillus subtilis natto toward different oxygen supply. (November 2020)

• Record Type: Journal Article
• Authors: Peng, Cheng; Zhu, Siyu; Lu, Jianyao; Hu, Xuechao; Ren, Lujing
• Is Part Of: Food research international. Volume 137(2020)
• Publication Date: 2020-11
• Subjects: Menaquinone-7 -- Bacillus natto -- Transcriptome -- Oxygen -- Vitamin K2 -- RNA-seq; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2020.109700
• Languages: English
• ISSNs: 0963-9969

Abstract

Graphical abstract: Highlights: The MK-7 yield at 200 rpm was 18.56 mg/L which two fold than that at 100 rpm. Several potential regulators were found to enhance MK-7 biosynthesis. High oxygen supply led to increased expression of genes about MK-7 metabolism. High oxygen supply led to decreased expression of sporulation gene. Most of genes regulating biofilm formation were down-regulated. Abstract: Menaquinone-7 (MK-7) is an important kind of vitamin K2 which plays significant roles in the treatment of coagulation and osteoporosis, and prevention of cardiovascular disease. This work was purposed to study the differences of gene expression at different oxygen supply conditions in Bacillus natto . The differences of fermentation characteristics, gene expression related to MK-7 biosynthesis, spore and biofilm formation were analyzed. The yield of MK-7 increased by two fold under high oxygen supply condition of 200 rpm. Further transcriptome analysis indicated that most of the enzymes in MK-7 biosynthesis pathway were also up-regulated. Moreover, glycerol kinase, fructose-bisphosphate aldolase and phosphofructokinase in glycolysis pathway were all up-regulated indicating that high oxygen supply can increase the consumption of substrate glycerol. Meanwhile, menD, encoded the rate-limiting enzyme in the MK pathway, was obviously up-regulated by 3.49-fold while most of the enzymes related to spore formation were down regulated at 200 rpm. Besides, superoxide dismutase (SOD2), catalase (CAT), hydroperoxide reductase (AhpF) and DNA-binding protein MrgA in the antioxidant defense system were up-regulated, while superoxide dismutase (SOD1) and glutathione peroxidase (GSH-Px) were down-regulated. These results could contribute to a better understanding for the effect of oxygen on the MK-7 production in Bacillus natto, and further analyze the molecular regulation mechanism of MK-7 biosynthesis.