Bacterial recovery from ancient glacial ice

摘要

Ice that from the bottom 18m of a 308 m ice core drilled from the Guliya ice cap on the Qinghan-Tibetan plateau in Western China is over 750000 years old and is the oldest glacial ice known to data. Fourteen bacterial isolates have been recovered from samples of this ice from ～296m below the surface (mbs). Based on 16S rDNA sequences, these are members of the a-and β-proteobacterial, actinobacterial and low-G+C Gram-positive bacterial lineages. 16S rDNA molecules have also been amplified directly, cloned and sequenced from the ice-core melt water. These originated from Pseudomonas and Acinetobacter γ-proteobacterial species. These results demonstrate that bacteria can be recovered from water ice that has frozen for time periods relevant to biological survival through terrestrial ice ages or during interplanetary transport.