P417-TH ANCIENT DNA AS A NEW BIOMARKER TO IDENTIFY PAST MICROBIAL COMMUNITIES: A STUDY ON PRESERVATION OF DNA IN ELLIS FJORD

• Main Authors: Arjan C. Boere, Ben Abbas, W. Irene, C. Rijpstra, John K. Volkman, Jaap S. Sinninghe Damsté, Marco J. L. Coolen
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Ellis Fjord; Antarc*; Antarctica
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.483.3905; http://www.imog2007.org/files/Thursday Posters/Thursday Posters Biomarkers/P417-TH Boere.pdf

The analysis of ancient DNA preserved in sediments provides a very specific and sensitive tool to study past microbial communities and hence obtain information about climate change in the past (Coolen et al., 2006). However, to date, little is known about differential preservation of DNA among taxa or celltypes while this information is essential for understanding to what extent this novel field provides an accurate mirror of past species composition. The Small Meromictic Basin (SMB) in Ellis Fjord, Antarctica offers an excellent opportunity to study preservation in more detail because ancient DNA is found to be well preserved under relatively constant anoxic, sulfidic conditions during the deposition of the up to 2700-year-old sediments analyzed. Our results show that during this period algal species from the oxygenated photic zone as well as obligate anoxygenic photolithoautotrophic green sulfur bacteria (GSB) from the sulfidic chemocline were preserved in the sediments. To study the preservation of DNA we conducted the following analyses: (1) a comparison of the qualitative (phylogenetic) information derived from rDNA sequence analysis of past diatoms, dinoflagellates and GSB vs. their specific lipid biomarkers (i.e.