Energetic and Environmental Constraints on the Community Structure of Benthic Microbial Mats in Lake Fryxell, Antarctica

Journal Article · 05 January 2020 · FEMS Microbiology Ecology

DOI: https://doi.org/10.1093/femsec/fiz207 · OSTI ID:1625319

Dillon, Megan L.  ^[1]; Hawes, Ian ^[2]; Jungblut, Anne D. ^[3]; Mackey, Tyler J. ^[4]; Eisen, Jonathan A. ^[5]; Doran, Peter T. ^[6]; Sumner, Dawn Y. ^[7]

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1. Lawrence Berkeley National Lab (LBNL), Berkeley, CA 94720 (United States). Climate and Ecosystem Sciences Div.; Univ. of California-Davis, Davis, CA (United States). Dept. of Earth and Planetary Sciences; DOE/OSTI
2. Coastal Marine Field Station, University of Waikato, 58 Cross Rd Sulphur Point Tauranga 3110, New Zealand
3. Life Sciences Department, Natural History Museum, Cromwell Rd South Kensington London SW7 5BD, UK
4. Massachusetts Institute of Technology (MIT), Cambridge, MA (United States). Dept. of Earth, Atmospheric, and Planetary Sciences
5. Univ. of California-Davis, Davis, CA (United States). Dept. of Evolution and Ecology
6. Louisiana State Univ., Baton Rouge, LA (United States). Geology and Geophysics
7. Univ. of California-Davis, Davis, CA (United States). Dept. of Earth and Planetary Sciences

Ecological communities are regulated by the flow of energy through environments. Energy flow is typically limited by access to photosynthetically active radiation (PAR) and oxygen concentration (O2). The microbial mats growing on the bottom of Lake Fryxell, Antarctica, have well-defined environmental gradients in PAR and (O2). We analyzed the metagenomes of layers from these microbial mats to test the extent to which access to oxygen and light controls community structure. We found variation in the diversity and relative abundances of Archaea, Bacteria and Eukaryotes across three (O2) and PAR conditions: high (O2) and maximum PAR, variable (O2) with lower maximum PAR, and low (O2) and maximum PAR. We found distinct communities structured by the optimization of energy use on a millimeter-scale across these conditions. In mat layers where (O2) was saturated, PAR structured the community. In contrast, (O2) positively correlated with diversity and affected the distribution of dominant populations across the three habitats, suggesting that meter-scale diversity is structured by energy availability. Microbial communities changed across covarying gradients of PAR and (O2). The comprehensive metagenomic analysis suggests that the benthic microbial communities in Lake Fryxell are structured by energy flow across both meter- and millimeter-scales.

• Research Organization: Lawrence Berkeley National Lab (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: Antarctic New Zealand Program; National Aeronautics and Space Administration (NASA) Astrobiologyence (SC); USDOE Office of SciNational Science Foundation (NSF) Division of Polar Programs
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1625319
• Journal Information: FEMS Microbiology Ecology, Journal Name: FEMS Microbiology Ecology Journal Issue: 2 Vol. 96; ISSN 0168-6496
• Publisher: Federation of European Microbiology SocietiesCopyright Statement
• Country of Publication: United States
• Language: English