Ecophysiology of soil bacteria in the vicinity of Henryk Arctowski Station, King George Island, Antarctica

Microbial abundance and diversity in soil samples from a ca. 0.2 km(2) area in Admiralty Bay, King George Island, were analysed by epifluorescence mic roscopy and plate counts. Total bacterial counts (TC) varied little compare d to the elemental content of the organic matter (c.f.(TC) 51% vs. c.v.(C,N ,S) 131, 171 and 204%, respectively). The number of copiotrophic colony for ming bacteria (CFU) fluctuated widely (CVCFU 171%). These factors together with the highly variable time course of colony formation by bacterial popul ations from each sampling site, indicate the high diversity and mosaic char acter of the microbial communities in the area. Morphological, physiologica l and enzymatic features of 48 bacterial strains isolated on nutrient agar were determined through API 20NE and API ZYM systems and by classical tests . These tests confirmed the high physiological diversity within the CFU pop ulations. Only 14 of the 48 isolates tested by API 20NE system were identif iable in the API database. (C) 2001 Elsevier Science Ltd. All rights reserv ed.