Guerrero Navarro, Alfons Eduard

Universitat Autònoma de Barcelona. Facultat de Biociències

Guerrero-Navarro, Alfons Eduard

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Subglacial lakes from the AntarcticSubglacial lakes are the ones with an ice layer on the surface. The ice layer can be as thick as many kilometers long.It is believed that the water from the lake stays liquid due to the geotermal activity, the pressure and the heat from the ice friccion.Nowadays, it is know that exists more than 150 subglacial lakes under the Antarctic ice layer spread all over the continent.Ice thickness provides different characteristics to the lake. These characteristics will condition the ecosystem in different ways, as there would be some lakes with photoautotrophic psychrophiles or other with chemolithoautotroph as the primary producers.Fig 1. Map of the Antarctic, subglacial rivers and lakes locationConclusions:- There are a lot of difficulties to sample these  environments due to:-The environment conditions (ex: weather)-Hight probability of introduce contaminationduring field work- Divergent opinions about protocols and        methods- Wide range of adaptations to this environment,   from energy source to morfologic, fisiologic or         biochemistry modifications, that makes possible  to live in those places.- A hight interest in preparing new expeditions to some moons from our Solar system, in order to  find life under the ice layer.  For instance, in Europe or Enceladus.Alfons Eduard Guerrero Navarro, Degree in MicrobologyLake Vida lake Vostok lakeIce thickness 800 to 970 m 3750 to 4150 mTemperature -13,4ºC ~ -3ºCIsolation time 2800 years Between 105 and 106yearsOxygen Anoxic Between 700 and1200 mg/LSalinity 18,8% Diversity of opinions(<1 -12%)Light Aphotic AphoticMicrobialdiversityAdditional informationVida lakeProteobacteria Two species of Gammaproteobacteria as the most abundant(Psychrobacter sp & Marinobacter sp)Abundant Epsilonproteobacteria. The cultivated species most closely related to the other species found was Sulfurovum sp with an identity of 95%.Lentisphaera Abundant group, without previously cultivated species.FirmicutesSpirochaeta One species with an identity of 97% with Sphaerochaeta spBacteroidetesVarrucomicrobiaTM7ActinobaacteriaVostok lakeβ-proteobacteria    Four Acidovorax sequences and a Comamonas sequenceα-proteobacteria An Afipia sequenceActinomyces A similar sequence to other Actinomyces from glacial iceReferences::-Siegert, M. J. et al. Physical, chemical and biological processes in Lake Vostok and other Antarcticsubglacial lakes. -Nature 414, 603–609 (2001).-Priscu, J. C. et. in Polar Lakes and Rivers (Vincent, W. F. & Laybourn-Parry, J.) 119-135 (Oxford UniversityPress, 2008).-Priscu, J. C. et al. Geomicrobiology of Subglacial Ice Above Lake Vostok, Antarctica. Science 286, 2141–2144 (1999).-Murray, A. E. et al. Microbial life at −13 °C in the brine of an ice-sealed Antarctic lake. PNAS (2012).Table1. Microbial diversity of different lakesFig 2. Cross-section from Vostok lakeTable 2. Additional information of different lakes

Subglacial lakes from the Antarctic

http://ddd.uab.cat/pub/tfg/2013/113233/TFG_alfonseduardguerreronavarro.pdf

Subglacial lakes from the Antarctic

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