Microorganisms in the accreted ice of Lake Vostok, Antarctica

D. M. Karl, D. F. Bird¹, K. Björkman, T. Houlihan, R. Shackelford and L. Tupas

School of Ocean and Earth Science and Technology (SOEST), University of Hawaii, Honolulu HI 96822

¹Departement des Sciences Biologiques, Universite du Quebec a Montreal, Casier Postal 8888, Succursale Centre-Ville, Montreal, QC, Canada, H3C 3P8

Abstract

Analysis of a portion of Vostok ice core number 5G, which is thought to contain frozen water derived from Lake Vostok, Antarctica (a body of liquid water located beneath about 4 kilometers of glacial ice), revealed between 2 x 10² and 3 x 10² bacterial cells per milliliter and low concentrations of potential growth nutrients. Lipopolysaccharide (a Gram-negative bacterial cell biomarker) was also detected at concentrations consistent with the cell enumeration data, which suggests a predominance of Gram-negative bacteria. At least a portion of the microbial assemblage was viable, as determined by the respiration of carbon-14 -labeled acetate and glucose substrates during incubations at 3°C and 1 atmosphere. These accreted ice data suggest that Lake Vostok may contain viable microorganisms.