| Title |
Characterization of the Depth-Related Changes in the Microbial Communities in Lake Hovsgol Sediment by 16S rRNA Gene-Based Approaches |
| Author |
Young-Do Nam1,2, Youlboong Sung1, Ho-Won Chang1, Seong Woon Roh1, Kyoung-Ho Kim1, Sung-Keun Rhee3, Jung-Chan Kim4, Joo-Yong Kim4, Jung-Hoon Yoon1, and Jin-Woo Bae1,2,5* |
| Address |
1Biological Resource Center, KRIBB, Daejeon 305-806, Republic of Korea, 2Korea University of Science and Technology, Daejeon 305-333, Republic of Korea, 3Department of Microbiology, Chungbuk National University, Chungbuk 361-763, Republic of Korea, 4Korea Institute of Geoscience and Mineral Resources, Daejeon 305-350, Republic of Korea, 5Environmental Biotechnology National Core Research Center, Gyeongsang National University, Jinju 660-701, Republic of Korea |
| Bibliography |
Journal of Microbiology, 46(2),125-136, 2008,
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| DOI |
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| Key Words |
Lake Hovsgol, sediment, DGGE, microbial diversity, 16S rRNA gene |
| Abstract |
The undisturbed sediment of Lake Hovsgol (Mongolia) is scientifically important because it represents a record of the environmental changes that took place between the Holocene (the present age) and Pleistocene (the last ice age; 12,000 14C years before present day). Here, we investigated how the current microbial
<br>communities change as the depth increases by PCR-denaturing gradient gel electrophoresis (DGGE) analysis of the 16S rRNA genes of the microbial communities. The microbial diversity, as estimated by the Shannon index, decreased as the depth increased. In particular, significant changes in archaeal diversity were observed in the middle depth (at 39~42 cm depth of total 60 cm depth) that marks the border between the Holocene and Pleistocene. Phylotype belonging to Beta- and Gamma-Proteobacteria were the predominant bacteria and most of these persisted throughout the depth examined. However, as the depth increased, some bacteria
<br>(some genera belonging to Beta-Proteobacteria, Nitrospira, and OP8-9) were not detectable while others (some genera belonging to Alpha-, Beta-, Gamma-Proteobacteria) newly deteced by DGGE. Crenarchaea were the predominant archaea and only one phylotype belonging to Euryarchaea was found. Both the
<br>archaeal and bacterial profiles revealed by the DGGE band patterns could be grouped into four and three subsets, respectively, subsets that were largely divided by the border between the Holocene and Pleistocene. Thus, the diversity of the current microbial communities in Lake Hovsgol sediments decreases with increasing
<br>depth. These changes probably relate to the environmental conditions in the sediments, which were shaped by the paleoclimatic events taking place between the Holocene and Pleistocene. |
