02475nas a2200229 4500008004100000020002200041245008100063210006900144260004400213300001300257520171900270653001201989653002202001653002502023653003102048653001702079100001502096700002102111700002302132700002402155856006602179 2019 eng d a978-3-030-16775-200aComplex Structure but Simple Function in Microbial Mats from Antarctic Lakes0 aComplex Structure but Simple Function in Microbial Mats from Ant aChambSpringer International Publishing a91 - 1203 a

Microbial mats growing under the permanent ice cover of Antarctic lakes occupy an exceptionally low-disturbance regime. Constant temperature, the absence of bioturbation or physical disturbance from wind action or ice formation allow mats to accumulate, as annual growth layers, over many decades or even centuries. In so doing they often assume decimetre scale, three-dimensional morphologies such as elaborate pinnacle structures and conical mounds. Here we combine existing and new information to describe microbial structures in three Antarctic lakes—simple prostrate mats in Lake Hoare, emergent cones in Lake Untersee and elaborate pinnacles in Lake Vanda. We attempt to determine whether structures emerge simply from uncoordinated organism-environment interactions or whether they represent an example of “emergent complexity”, within which some degree of self-organisation occurs to confer a holistic functional advantage to component organisms. While some holistic advantages were evident from the structures—the increase in surface area allows greater biomass and overall productivity and nutrient exchange with overlying water—the structures could also be understood in terms of potential interactions between individuals, their orientation and their environment. The data lack strong evidence of coordinated behaviour directed towards holistic advantages to the structure, though hints of coordinated behaviour are present as non-random distributions of structural elements. The great size of microbial structures in Antarctic lakes, and their relatively simple community composition, makes them excellent models for more focused research on microbial cooperation.

10abiofilm10amicrobial ecology10amicrobial structures10aself-organising structures10astromatolite1 aHawes, Ian1 aSumner, Dawn, Y.1 aJungblut, Anne, D.1 aHurst, Christon, J. uhttps://link.springer.com/chapter/10.1007/978-3-030-16775-2_403959nas a2200205 4500008004100000022001400041245008900055210006900144260001200213300001600225490000700241520327000248100001403518700002303532700001503555700002303570700002103593700002203614856011703636 2015 eng d a0722-406000aCyanobacterial diversity in benthic mats of the McMurdo Dry Valley lakes, Antarctica0 aCyanobacterial diversity in benthic mats of the McMurdo Dry Vall c01/2015 a1097 - 11100 v383 a
Perennially ice-covered, meromictic lakes in the McMurdo Dry Valleys, Antarctica, are useful models to study the relationship between cyanobacterial and environmental variables. They have rich benthic cyanobacterial mat accumulations and stable stratification of physical and chemical conditions. Here, we evaluated cyanobacteria from benthic mats from multiple depths in three geographically separated ice-covered lakes, Lakes Vanda, Hoare and Joyce, using 16S rRNA gene clone libraries. We identified 19 ribotypes, mostly Oscillatoriales and several
Chroococcales, as well as potentially novel cyanobacterial ribotypes. The majority of ribotype diversity was shared between lakes, and only a weak relationship between ribotype community structure and environmental variables was evident. Multivariate analysis of all lake–depth combinations implied that photosynthetically active radiation, dissolved reactive phosphorus and conductivity were potentially important for shaping benthic communities in McMurdo Dry Valley lakes. Cyanobacterial-specific pigment signature analysis by high-performance liquid chromatography
showed that the cyanobacterial communities responded to light conditions similarly, irrespective of community composition. The results imply a capability within a suite of cyanobacteria to colonise, adapt and grow across broad environmental ranges and geographic space, and such adaptability may provide a high degree of community resistance and resilience to future climate-driven environmental change in Antarctic terrestrial aquatic
ecosystems.
1 aZhang, L.1 aJungblut, Anne, D.1 aHawes, Ian1 aAndersen, Dale, T.1 aSumner, Dawn, Y.1 aMackey, Tyler, J. uhttp://link.springer.com/10.1007/s00300-015-1669-0http://link.springer.com/content/pdf/10.1007/s00300-015-1669-0