Open Access Repository

In situ light responses of the proteorhodopsin-bearing Antarctic sea-ice bacterium, Psychroflexus torques

Burr, DJ, Martin, A ORCID: 0000-0001-8260-5529, Maas, EW and Ryan, KG 2017 , 'In situ light responses of the proteorhodopsin-bearing Antarctic sea-ice bacterium, Psychroflexus torques' , ISME Journal, vol. 11 , pp. 2155-2158 , doi:

Full text not available from this repository.


Proteorhodopsin (PR) is a wide-spread protein found in many marine prokaryotes. PR allows for the potential conversion of solar energy to ATP, possibly assisting in cellular growth and survival during periods of high environmental stress. PR utilises either blue or green light through a single amino acid substitution. We incubated the PR-bearing bacterium Psychroflexus torquis 50 cm deep within Antarctic sea ice for 13 days, exposing cultures to diurnal fluctuations in light and temperature. Enhanced growth occurred most prominently in cultures incubated under irradiance levels of ∼50 μmol photons m−2 s−1, suggesting PR provides a strong selective advantage. In addition, cultures grown under blue light yielded over 5.5 times more live cells per photon compared to green-light incubations. Because P. torquis expresses an apparently ‘green-shifted’ PR gene variant, this finding infers that the spectral tuning of PR is more complex than previously thought. This study supports the theory that PR provides additional energy to bacteria under sub-optimal conditions, and raises several points of interest to be addressed by future research.

Item Type: Article
Authors/Creators:Burr, DJ and Martin, A and Maas, EW and Ryan, KG
Keywords: Antarctica, sea ice algae, proteorhodopsin
Journal or Publication Title: ISME Journal
Publisher: Nature Publishing Group
ISSN: 1751-7362
DOI / ID Number:
Copyright Information:

© 2017 International Society for Microbial Ecology All rights reserved

Related URLs:
Item Statistics: View statistics for this item

Actions (login required)

Item Control Page Item Control Page