Proteorhodopsin Overproduction Enhances the Long-Term Viability of Escherichia coli

• Yizhi Song ^[1] ; Michaël L. Cartron ^[2] ; Philip J. Jackson ^[2] ; Paul A. Davison ^[2] ; Mark J. Dickman ^[2] ; Di Zhu ^[2] ; Wei E. Huang ^[1] ; C. Neil Hunter ^[2]
  1. [1] University of Oxford

     University of Oxford

     Oxford District, Reino Unido

     
  2. [2] University of Sheffield

     University of Sheffield

     Reino Unido

     
• Localización: Applied and Environmental Microbiology, ISSN 0099-2240, Vol. 86, Nº 1, 2020
• Idioma: inglés
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• Resumen

  • Proteorhodopsin (PR) is part of a diverse, abundant, and widespread superfamily of photoreactive proteins, the microbial rhodopsins. PR, a light-driven proton pump, enhances the ability of the marine bacterium Vibrio strain AND4 to survive and recover from periods of starvation, and heterologously produced PR extends the viability of nutrient-limited Shewanella oneidensis. We show that heterologously produced PR enhances the viability of E. coli cultures over long periods of several weeks and use single-cell Raman spectroscopy (SCRS) to detect PR in 9-month-old cells. We identify a densely packed and consequently stabilized cell membrane as the likely basis for extended viability. Similar considerations are suggested to apply to marine bacteria, for which high PR levels represent a significant investment in scarce metabolic resources. PR-stabilized cell membranes in marine bacteria are proposed to keep a population viable during extended periods of light or nutrient limitation, until conditions improve.