The change of the state of cell membrane can enhance the synthesis of menaquinone in Escherichia coli
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Menaquinone (MK) was an attractive membrane-bound intracellular chemical. To enhance its production, we tried to find the relationship between its synthesis and the state of cell membrane in producing strain. Due to non-ionic surfactant-polyoxyethylene oleyl ether (POE) and plant oil-cedar wood oil (CWO) can typically increase extracellular secretion and intracellular synthesis of MK respectively, the effect of these two substances on cell morphology, physical properties of cell membrane was investigated. Finally, two engineering strains were constructed to verify whether the state of cell membrane can enhance MK synthesis. The result showed that the edge of cells was broken when POE added in the medium. Other physical properties such as total fatty acid content decreased by 40.7% and the ratio of saturated fatty acids to unsaturated fatty acids decreased from 1.58 ± 0.05 to 1.31 ± 0.04. Meanwhile, cell membrane leakage was enhanced from 7.14 to 64.31%. Different from POE group, cell membrane was intact in CWO group. Moreover, the ratio of saturated fatty acids to unsaturated fatty acids increased from 1.58 ± 0.05 to 1.78 ± 0.04 and the average lipid length decreased from 16.05 ± 0.08 to 15.99 ± 0.10. Two constructed strains, especially Escherichia coli DH5α FatB, exhibited strong MK secretion ability and the extracellular MK reached 10.71 ± 0.19 mg/L. An understanding of these functionary mechanisms could not only provide a new idea for the synthesis of MK, but also provide a reference to increase the yield of intracellular membrane-bound metabolites.
KeywordsMenaquinone Cell membranes Membrane fluidity Leakage
The study was supported by the National Nature Science Foundation of China (No. 31501465, 31471615), the National High-tech R&D Program (No. 2014AA021704), Anhui Provincial Nature Science Foundation (No. 1608085QC54), Anhui Higher Education Exchange Program for Young Talents (No. gxfxZD2016109) and Anhui Provincial Undergraduate Innovation and Entrepreneurship Program (No.201510363130) and the National Undergraduate Innovation and Entrepreneurship Program (No. 2016103630055).
- Ishida Y (2008) Vitamin K2. Clin Calcium 18:1476–1482Google Scholar
- Jacques NA, Jacques VL, Wolf AC, Wittenberger CL (1985) Does an increase in membrane unsaturated fatty acids account for Tween 80 stimulation of glucosyltransferase secretion by Streptococcus salivarius? J Gen Microbiol 131:67–72Google Scholar
- Liu Y, Zheng ZM, Qiu HW, Zhao GH, Liu H, Li ZM, Wu HF, Tan M (2014) Surfactant supplementation to enhance the production of vitamin K2 metabolites in shake flask cultures using Escherichia. sp mutant FM3-1709. Food Technol Biotechnol 52(3):269–275Google Scholar
- Suvarna K, Stevenson D, Meganathan R, Hudspeth MES (1998) Menaquinone (vitamin K2) biosynthesis: localization and characterization of the menA Gene from Escherichia coli. J Bacteriol 180(10):2782–2787Google Scholar
- Taguchi H, Kita S, Tani Y (1991) Enzymatic alteration in the shikimate pathway during derivation of menaquinone-4-producing mutants of Flavobacterium sp. 238–7. Agric Biol Chem 55:769–773Google Scholar
- Yoshiki T, Hisataka T (1988) Excretion of menaquinone-4 by a mutant of Flavobacterium sp. 238-7 in a detergent- supplemented culture. Agric Biol Chem 52(2):449–454Google Scholar