Hori Ryuji, Nishida Takanori, Okuyama Hidetoshi
Course in Environmental Molecular Biology and Microbial Ecology, Division of Biosphere Science, Graduate School of Environmental Science, Hokkaido University, Kita-ku, Sapporo 060-0810, Japan.
Open Microbiol J. 2011;5:114-8. doi: 10.2174/1874285801105010114. Epub 2011 Nov 3.
The growth of Escherichia coli DH5α recombinants producing eicosapentaenoic acid (EPA) (DH5αEPA+) and those not producing EPA (DH5αEPA-) was compared in the presence of hydrophilic or hydrophobic growth inhibitors. The minimal inhibitory concentrations of hydrophilic inhibitors such as reactive oxygen species and antibiotics were higher for DH5αEPA+ than for DH5αEPA-, and vice versa for hydrophobic inhibitors such as protonophores and radical generators. E. coli DH5α with higher levels of EPA became more resistant to ethanol. The cell surface hydrophobicity of DH5αEPA+ was higher than that of DH5αEPA-, suggesting that EPA may operate as a structural constituent in the cell membrane to affect the entry and efflux of hydrophilic and hydrophobic inhibitors.
在亲水性或疏水性生长抑制剂存在的情况下，对产二十碳五烯酸（EPA）的大肠杆菌DH5α重组体（DH5αEPA +）和不产EPA的重组体（DH5αEPA -）的生长进行了比较。对于亲水性抑制剂，如活性氧和抗生素，DH5αEPA +的最低抑菌浓度高于DH5αEPA -；而对于疏水性抑制剂，如质子载体和自由基产生剂，情况则相反。EPA含量较高的大肠杆菌DH5α对乙醇的耐受性更强。DH5αEPA +的细胞表面疏水性高于DH5αEPA -，这表明EPA可能作为细胞膜的结构成分发挥作用，影响亲水性和疏水性抑制剂的进出。
