Comparison of the microbial diversity at different depths of the GISP2 Greenland ice core in relationship to deposition climates

摘要: This study presents comparative geochemical, microbiological and molecular analyses of Greenland GISP2 ice core samples representing different depths, ages, deposition climates, in situ temperatures, gas ionic compositions. Our goal was to determine whether specific organisms, preserved at correlate with past climate characteristics recorded chronologically layers. Three clear were selected from 2495, 2545 2578 m represent distinct climatic periods milder (-45 degrees C), colder (-51 C) warmer (-39 two Marine Isotope Stages, MIS3 (2495 m) MIS4 (2545 m). Results showed higher microbial abundance deposited during climates ion content. The constructed universal SSU rRNA gene clone libraries dominated by Gram-positive sequences (55-65%), had fewer Proteobacteria (6-9%) Archaea (1%). 2495 library differed the other being Actinobacteria (55%) rather than Firmicutes. Fungi more prevalent (40%). For comparison, a an older silty sample (3044 possibly originating underlying permafrost (high temperature, high methane cell numbers). It significantly diversity not found libraries. bacterial fungal isolates related organisms Asian deserts, marine aerosols volcanic dust, suggesting these environments as sources microorganisms. observed differences patterns, especially library, support idea that local conditions global atmospheric circulations time have influenced origin composition populations depths ice. Further investigations may lead development 'markers' for identifying climates.