时间：2019年12 月30日 10：50-11：50
Viruses have been found everywhere that life has been found, including deep subsurface environments. While there is a good understanding that microorganisms play an important role shaping geological processes on Earth, the impact of viruses on these processes is only recently starting to be understood. However, there is still very little known about viruses within Earth’s subsurface. Our recent findings from deep subseafloor sediments suggest that viruses may be more important than previously expected. I recently developed a new method for the detection of viruses from sediment containing substantially lower biomass than previously possible. This new method can detect up to 200x more viruses compared to previous methods. Because previous publications highly underestimated subsurface virus abundance, the global abundance of subsurface viruses must be revised using the new method. Based on these results, viruses may be a globally important contributor of organic carbon in the subsurface. Virus infection in deep subsurface microbial communities may also be important. Recently, I discovered the deepest viruses ever studied from deep subseafloor sediment. Fourteen novel virus genomes were metagenomically reconstructed from coal bed layers collected from 2km below the seafloor (IODP Exp. 337, Shimokita, Japan). Five of the virus genomes were also detected as integrated into bacterial genomes, suggesting the possible presence of virus infection and interactions such as lateral gene transfer in the subseafloor. The roles of viruses in the functioning of the deep subsurface ecosystem remain to be further explored, especially with regard to cell mortality and carbon cycling. My future research program intends to investigate the nature and function of viral infection under the extreme conditions of energy limitation in the deep subsurface, which remains an important topic in the next decade of investigations into deep subsurface life.
Donald Pan specializes in interdisciplinary research. His research focuses on viruses in subsurface environments by merging the fields of virology, microbiology, bioinformatics, geology, chemistry, and oceanography. He was a postdoctoral fellow at the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), where he worked with Drs. Ken Takai and Fumio Inagaki. While he was working in Japan, he participated in IODP Expeditions and helped the Japanese ocean drilling community with creating a new framework for “scientific ocean drilling beyond 2023”. Donald Pan received his PhD from the United States at the University of Nebraska, where he studied viruses in terrestrial groundwater aquifers and their influence on water quality. He received a Bachelors Degree from the University of California Berkeley where he studied Microbial Biology and Astrophysics. He worked at NASA where he participated in astrobiology and bioengineering projects. In addition to science research, Donald also has an interest in using science to solve societal problems. He was selected as a “Future Leader” of the Science & Technology in Society Forum, and he has also studied water policy and management in Central Europe.