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Koh et al, 2010 - PR-bearing bacteria in antarctic sea ice.pdf (822.03 kB)

Proteorhodospin-bearing bacteria in Antarctic sea ice

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journal contribution
posted on 2023-05-17, 05:22 authored by Koh, EY, Atamna-Ismaeel, N, Martin, AR, Cowie, ROM, Beja, O, Davy, SK, Maas, EW, Ryan, KG
Proteorhodopsins (PRs) are widespread bacterial integral membrane proteins that function as light-driven proton pumps. Antarctic sea ice supports a complex community of autotrophic algae, heterotrophic bacteria, viruses, and protists that are an important food source for higher trophic levels in ice-covered regions of the Southern Ocean. Here, we present the first report of PR-bearing bacteria, both dormant and active, in Antarctic sea ice from a series of sites in the Ross Sea using gene-specific primers. Positive PR sequences were generated from genomic DNA at all depths in sea ice, and these sequences aligned with the classes Alphaproteobacteria, Gammaproteobacteria, and Flavobacteria. The sequences showed some similarity to previously reported PR sequences, although most of the sequences were generally distinct. Positive PR sequences were also observed from cDNA reverse transcribed from RNA isolated from sea ice samples. This finding indicates that these sequences were generated from metabolically active cells and suggests that the PR gene is functional within sea ice. Both blue-absorbing and green-absorbing forms of PRs were detected, and only a limited number of blue-absorbing forms were found and were in the midsection of the sea ice profile in this study. Questions still remain regarding the protein’s ecological functions, and ultimately, field experiments will be needed to establish the ecological and functional role of PRs in the sea ice ecosystem.


Publication title

Applied and Environmental Microbiology










Institute for Marine and Antarctic Studies


Amer Soc Microbiology

Place of publication

1752 N St Nw, Washington, USA, Dc, 20036-2904

Rights statement

Copyright © 2010, American Society for Microbiology

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  • Open

Socio-economic Objectives

Expanding knowledge in the biological sciences

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