Lake Suigetsu is a small tectonic lake in central Japan containing annually laminated (varved) sediment. An ongoing international project is combining over 600 radiocarbon ages from terrestrial leaf macrofossils with varve ages from the core (SG06) to generate a terrestrial radiocarbon calibration model stretching back to the limit of radiocarbon dating (c. 50, 000 BP). This core chronology provides an ideal basis for quantitative studies of climate change and palaeoenvironmental reconstruction. The present study aimed to identify and elucidate the diversity of the microbial communities down the sediment core with the intention to develop novel biomarkers for past climate change using a culture-dependent approach. Lake sediment samples taken at 932.44, 1363.76 and 2434 cm composite depths, representing c. 6860, 10911 and 23600 years before present were subjected to dispersion and differential centrifugation (DDC) coupled with selective isolation. A total of 204 representative isolates were further identified using 16S rRNA gene sequencing, with 139 found to reside within 18 genera belonging to the class Actinobacteria. Five genera were recovered solely from the 932.44 cm sample, with eight genera residing within the 1363.76 cm sample. Only two genera were recovered from all three samples. This may suggest that the development of the prokaryotic community during and post-deposition could be influenced by climatic conditions at the time of deposition and/or community development during burial. Results support the use of prokaryotic communities as potential palaeoenvironmental indicators.
|Publication status||Published - 2011|
|Event||16th International Symposium on the Biology of Actinomycetes - Vallarta, Mexico|
Duration: 1 Jan 2011 → …
|Conference||16th International Symposium on the Biology of Actinomycetes|
|Period||1/01/11 → …|