Subject(s)
Bacterial Physiological Phenomena , Antarctic Regions , Cold Climate , Diatoms , Environment , Eukaryota , Ice , Microscopy, Fluorescence , Water MicrobiologyABSTRACT
The microbiological investigations of the Antarctic ice core at the Vostok station become especially important in connection with the discovery of an subglacial lake in this region. This lake is considered by the world-wide scientific community to be an important object for searching for relict forms of life on the Earth and also as a model for solving a number of problems of exobiology--for instance for development of methods to penetrate into underice sea at Europe--Jupiter's satellite. For the first time the Antarctic ice core samples were taken from the horizons which correspond to the basal zone (3534-3541 m) and to the accreation ice zone (3555-3611 m) above the subglacial lake Vostok. As a result of the microbiological investigations it was shown that the total number of microbial cells have been in the same range of quantities as at the upper, younger horizons and varied from 1.3 x 10(2) up to 9.6 x 10(2) cl/ml. Some periodicity in the cell concentration and in their morphological diversity was revealed along the core. The maximal number and the greatest morphological variety were detected at horizons with the depth of 3534, 3555 and 3595 m. A drop in the cell concentration two or three times as much was found in ice layers under each of the above mentioned horizons. The discovered stratification is apparently connected with the periodicity of the lake water interactions with the basal ice layer and obviously depends on the complex natural events which took place in the geological history of our planet.
Subject(s)
Bacteria/isolation & purification , Cold Climate , Exobiology , Fresh Water/microbiology , Ice/analysis , Water Microbiology , Antarctic Regions , Bacteria/classification , Caulobacter/isolation & purification , Colony Count, Microbial , Diatoms/isolation & purification , Eukaryota/isolation & purification , Fungi/isolation & purification , PeriodicityABSTRACT
A technique has been developed for obtaining ice samples under sterile conditions for microbiological analyses as a function of ice thicknesses and with a view to clarifying the possibility of long term microbial anabiosis under permafrost conditions. For the first time microbiological studies from the surface down to 312 meters in the Vostok station region have been carried out and the distribution of microorganisms in the strata studied has been clarified. Microorganisms occur rather rarely, and their distribution is of a random character, independent of the depth of sampling. Viable microorganisms have been found in the ice horizons approximately as old as 8-13 thousand years.
