State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, 214122, China; International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China; Key Laboratory of Industrial Biotechnology of Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
College of Biochemical Engineering, Anhui Polytechnic University, Wuhu, 241000, China.
Enzyme Microb Technol. 2019 May;124:9-16. doi: 10.1016/j.enzmictec.2019.01.009. Epub 2019 Jan 24.
Lipopolysaccharides, the major molecules in the outer membrane of Escherichia coli, affect the behavior of bacteria including outer membrane permeability, but its influence on lycopene production in E. coli has never been reported. In this study, the effects of lipopolysaccharides with different structures on lycopene biosynthesis were investigated. Firstly, the heterogenous crtEBI operon were overexpressed in 10 LPS mutant strains of E. coli W3110 (ΔwaaC, ΔwaaF, ΔwaaY, ΔwaaG, ΔwaaR, ΔwaaO, ΔwaaU, ΔwaaP, ΔwaaY and ΔwaaB), and their ability to produce lycopene were compared. ΔwaaC/pWSK29-crtEBI, ΔwaaF/pWSK29-crtEBI and ΔwaaY/pWSK29-crtEBI produced 4.19, 4.20, and 3.81 mg/g lycopene, respectively, while the control W3110/pWSK29-crtEBI produced 3.71 mg/g lycopene; the other strains produced less lycopene than the control. In order to enhance lycopene production, genes dxr, dxr, ispA, and idi were overexpressed in ΔwaaC/pWSK29-crtEBI, ΔwaaF/pWSK29-crtEBI individually or in combination, and the lycopene production in each strain was analyzed. The maximum yield of 5.39 mg/g was achieved in ΔwaaC/pWSK29-crtEBI-SRA, which is 142% higher than that in W3110/pWSK29-crtEBI. The results indicate that the length of lipopolysaccharide affects lycopene biosynthesis in E. coli, and the shorter lipopolysaccharide and higher outer membrane permeability might be beneficial to lycopene biosynthesis.
脂多糖是大肠杆菌外膜的主要分子，影响细菌的行为，包括外膜通透性，但它对大肠杆菌中番茄红素生产的影响从未有过报道。在这项研究中，研究了具有不同结构的脂多糖对番茄红素生物合成的影响。首先，在大肠杆菌 W3110 的 10 种 LPS 突变株（Δ waaC、Δ waaF、Δ waaY、Δ waaG、Δ waaR、Δ waaO、Δ waaU、Δ waaP、Δ waaY 和 Δ waaB）中过表达异源 crtEBI 操纵子，并比较它们生产番茄红素的能力。Δ waaC/pWSK29-crtEBI、Δ waaF/pWSK29-crtEBI 和 Δ waaY/pWSK29-crtEBI 分别产生了 4.19、4.20 和 3.81mg/g 的番茄红素，而对照 W3110/pWSK29-crtEBI 产生了 3.71mg/g 的番茄红素；其他菌株产生的番茄红素少于对照。为了提高番茄红素的产量，在Δ waaC/pWSK29-crtEBI、Δ waaF/pWSK29-crtEBI 中单独或组合过表达基因 dxr、dxr、ispA 和 idi，并分析了每个菌株的番茄红素产量。Δ waaC/pWSK29-crtEBI-SRA 的最大产量为 5.39mg/g，比 W3110/pWSK29-crtEBI 提高了 142%。结果表明，脂多糖的长度影响大肠杆菌中番茄红素的生物合成，较短的脂多糖和较高的外膜通透性可能有利于番茄红素的生物合成。
