title: The change of the state of cell membrane can enhance the synthesis of menaquinone in Escherichia coli.
abstract: 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.
authors.affiliation: College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China. liuyan@ahpu.edu.cn.|Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Science, Hefei, 230031, China. liuyan@ahpu.edu.cn.|VCU Massey Cancer Center, VCU Institute of Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA. liuyan@ahpu.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
authors.forename: Xiu-Min
authors.initials: XM
authors.lastname: Ding
authors.affiliation: College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China. xuezl@ahpu.edu.cn.
authors.forename: Zheng-Lian
authors.initials: ZL
authors.lastname: Xue
authors.affiliation: College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
authors.forename: Liu-Xiu
authors.initials: LX
authors.lastname: Hu
authors.affiliation: College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
authors.forename: Ning-Juan
authors.initials: NJ
authors.lastname: Zhang
authors.affiliation: College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
authors.forename: Zhou
authors.initials: Z
authors.lastname: Wang
authors.affiliation: College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Yang
authors.affiliation: College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Cheng
authors.affiliation: College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
authors.forename: Ming-Hong
authors.initials: MH
authors.lastname: Chen
authors.affiliation: VCU Massey Cancer Center, VCU Institute of Molecular Genetics, Virginia Commonwealth University School of Medicine, Richmond, VA, 23298, USA.
authors.forename: Zhuang-Zhuang
authors.initials: ZZ
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Ion Beam Bioengineering, Hefei Institutes of Physical Science, Chinese Academy of Science, Hefei, 230031, China.
authors.forename: Zhi-Ming
authors.initials: ZM
authors.lastname: Zheng
mesh_terms: D002462:Cell Membrane / Q000187:drug effects* / Q000648:ultrastructure; D004926:Escherichia coli / Q000737:chemistry / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D005227:Fatty Acids / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D060847:Metabolic Engineering; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D015394:Molecular Structure; D009154:Mutation; D009822:Oils, Volatile / Q000494:pharmacology*; D011092:Polyethylene Glycols / Q000494:pharmacology*; D024482:Vitamin K 2 / Q000378:metabolism*
chemical_list: D005227:Fatty Acids; D005231:Fatty Acids, Unsaturated; D009822:Oils, Volatile; C478746:polyoxyethylene-10-oleyl ether; D024482:Vitamin K 2; D011092:Polyethylene Glycols; C042023:cedarwood oil
keywords: Cell membranes; Leakage; Membrane fluidity; Menaquinone