Microflora in the basal strata at Antarctic ice core above the Vostok lake.

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. c2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.