Hydrophilic and Hydrophobic Compounds Antithetically Affect the Growth of Eicosapentaenoic Acid-Synthesizing Escherichia coli Recombinants

Ryuji Horia, #, Takanori Nishidab, #, §, Hidetoshi Okuyamaa, b, *
a 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
b Laboratory of Environmental Molecular Biology, Faculty of Environmental Earth Science, Hokkaido University, Kita-ku, Sapporo 060-0810, Japan

Article Metrics

CrossRef Citations:
Total Statistics:

Full-Text HTML Views: 3530
Abstract HTML Views: 2743
PDF Downloads: 900
Total Views/Downloads: 7173
Unique Statistics:

Full-Text HTML Views: 1787
Abstract HTML Views: 1564
PDF Downloads: 607
Total Views/Downloads: 3958

Creative Commons License
© Hori et al.; Licensee Bentham Open.

open-access license: This is an open access article licensed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted, non-commercial use, distribution and reproduction in any medium, provided the work is properly cited.

* Address correspondence to this author at Hokkaido University, Faculty of Environmental Earth Science, Hokkaido University, Kita-ku, Sapporo 060- 0810, Japan; Tel: +81-11-706-4523; Fax: +81-11-706-4523; E-mail:
# These authors contributed equally to this work.
§ Present address: Akita Research Institute for Food and Brewing (ARIF), Araya-machi, Akita, Japan


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.

Keywords: Cell hydrophobicity, eicosapentaenoic acid, membrane-shielding effect, minimal inhibitory concentration, organic solvent.