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In situ light responses of the proteorhodopsin-bearing Antarctic sea-ice bacterium, Psychroflexus torques
journal contribution
posted on 2023-05-19, 05:17 authored by Burr, DJ, Martin, A, Maas, EW, Ryan, KGProteorhodopsin (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.
History
Publication title
ISME JournalVolume
11Pagination
2155-2158ISSN
1751-7362Department/School
Institute for Marine and Antarctic StudiesPublisher
Nature Publishing GroupPlace of publication
United KingdomRights statement
© 2017 International Society for Microbial Ecology All rights reservedRepository Status
- Restricted