Microstructure and cyanobacterial composition of microbial mats from the High Arctic
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Arctic lakes, ponds and streams contain benthic microbial mats that are dominated by cyanobacteria, and these communities often account for a large proportion of the total ecosystem biomass and productivity. The vertical structure and composition of mats from two different aquatic habitats in the Canadian High Arctic, Ward Hunt Lake and a polar desert stream were analyzed in detail by microscopy techniques. Two distinct layers were identified in each mat: a surface layer with a high density of cells and associated extracellular polymeric substances (EPS), and a less cohesive bottom layer with an accumulation of mineral particles. The matrix formed by the cyanobacterial filaments and EPS produced the complex microstructure of all three mats, and likely favoured different microenvironments where specialized microbial interactions and biomineralization processes could take place. Structural and compositional differences were found among the mats. The lake mat had a surface layer of Dichothrix, and contained abundant particles of calcium carbonate, while Tychonema-like and Tolypothrix-like appeared mainly in the stream mats, along with a higher diversity of Chroococcales. A black microbial mat from one of the stream sites had markedly lower diversity than the other mat types. The observed differences in cyanobacterial composition and physical structure may be related to habitat stability and the availability of liquid water.
KeywordsCyanobacteria Habitat stability Microbial ecology Polar regions Water availability
We are grateful to PCPS for the logistic support to the High Arctic and Parks Canada for access to their facilities in Quttinirpaaq National Park. This project was funded by the Grants REN2000-0435, CGL2005-06549, POL2006-06635 and CTM2011-28736 from Spanish Ministry of Economy and Competitiveness, with funding of the microscopy studies through grants CTM2012-38222-C02-02 and CGL2013-42509. Additional support was provided by the Natural Sciences and Engineering Research Council of Canada and the Canada Research Chair program. The authors would like to thank to ICA and the MNCN (CSIC) microscopy services staff for technical assistance.
- Decho AW (2000) Exopolymer microdomains as a structuring agent for heterogeneity within microbial biofilms. In: Riding RE, Awramik SM (eds) Exopolymer microdomains as a structuring agent for heterogeneity within microbial biofilms. Springer, Berlin, pp 9–15Google Scholar
- Komárek J, Anagnostidis K (1989) Modern approach to the classification system of Cyanophytes, 4–Nostocales. Arch Hydrobiol Suppl. 82/Algol Stud 56:247–345Google Scholar
- Komárek J, Anagnostidis, K. (1999) Cyanoprokaryota. 1. Chroococcales. In: Ettl H, Gärtner G, Heynig H, Mollenhauer D (eds) Süßwasserflora von Mitteleuropa. Begründet von A. Pascher. Band 19/1. Spektrum, Akademischer Verlag, Heidelberg, pp 1–548Google Scholar
- Komárek J, Anagnostidis K (2005) Cyanoprokaryota. 2. Teil: Oscillatoriales. In: Büdel B, Gärdner G, Krienitz L, Schagerl M. (eds) Süsswasserflora von Mitteleuropa, vol. 19/2. Elsevier, MünchenGoogle Scholar
- Quesada A, Vincent WF (2012) Cyanobacteria in the cryosphere: snow, ice and extreme cold. In: Whitton BA (ed) Ecology of Cyanobacteria II. Springer, New York, pp 387–399Google Scholar
- Quesada A, Sanchez-Contreras M, Fernández-Valiente E (2001) Tolerance of Antarctic cyanobacterial microbial mats to natural UV radiation. Nova Hedwigia 123:275–290Google Scholar
- Tytgat B, Verleyen E, Obbels D, Peeters K, De Wever A, D’hondt S, De Meyer T, Van Criekinge W, Vyverman W, Willems A (2014) Bacterial diversity assessment in Antarctic terrestrial and aquatic microbial mats: a comparison between bidirectional pyrosequencing and cultivation. PLoS One 9:e97564. doi: 10.91371/journal.pone.0097564 CrossRefPubMedCentralPubMedGoogle Scholar
- Villeneuve V, Vincent WF, Komárek J (2001) Community structure and microhabitat characteristics of cyanobacterial mats in an extreme high Arctic environment: Ward Hunt Lake. Nova Hedwigia 123:199–224Google Scholar
- Vincent WF (1988) Microbial ecosystems of Antarctica. Cambridge University Press, CambridgeGoogle Scholar
- Vincent WF, Quesada A (2012) Cyanobacteria in high latitude lakes, rivers and seas. In: Whitton BA (ed) Ecology of Cyanobacteria II. Springer, New York, pp 371–385Google Scholar