Japan Geoscience Union Meeting 2015

Presentation information


Symbol M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS32] Drilling Earth Science

Sun. May 24, 2015 2:15 PM - 4:00 PM 304 (3F)

Convener:*Saneatsu Saito(Japan Agency for Marine-Earth Science and Technology), Katsuyoshi Michibayashi(Institute of Geosciences, Shizuoka University), Tetsuro Hirono(Department of Earth and Space Science, Graduate School of Science, Osaka University), Keita Umetsu(Japan Agency for Marine-Earth Science and Technology), Chair:Arito Sakaguchi(Yamaguchi Univ.), Kentaro Omura(National Research Institute for Earth Science and Disaster Prevention)

3:30 PM - 3:45 PM

[MIS32-20] Intact preservation of environmental samples by freezing under an alternating magnetic field

*Yuki MORONO1, Takeshi TERADA2, Yuhji YAMAMOTO3, Nan XIAO1, Takehiro HIROSE1, Masaya SUGENO4, Norio OHWADA4 (1.Kochi Institute for Core Sample Research, JAMSTEC, 2.Marine Works Japan Ltd., 3.ABI Co. Ltd., 4.Center for Advanced Marine Core Research, Kochi University)

Keywords:Subseafloor sediment, Freezing, Cell Alive System

The study of environmental samples requires a preservation system that stabilizes the sample structure, including cells and biomolecules. To address this fundamental issue, we tested the cell alive system (CAS)-freezing technique for subseafloor sediment core samples. In the CAS-freezing technique, an alternating magnetic field is applied during the freezing process to produce vibration of water molecules and achieve a stable, super-cooled liquid phase. Upon further cooling, the temperature decreases further, achieving a uniform freezing of sample with minimal ice crystal formation. In this study, samples were preserved using the CAS and conventional freezing techniques at 4, -20, -80 and -196 (liquid nitrogen)oC. After 6 months of storage, microbial cell counts by conventional freezing significantly decreased (down to 10.7% of initial), whereas that by CAS-freezing resulted in minimal. When Escherichia coli cells were tested under the same freezing conditions and storage for 2.5 months, CAS-frozen E. coli cells showed higher viability than the other conditions. In addition, an alternating magnetic field does not impact on the direction of remanent magnetization in sediment core samples, although slight partial demagnetization in intensity due to freezing was observed. Consequently, our data indicate that the CAS technique is highly useful for the preservation of environmental samples.