Abstract:

Ammonia-oxidizing archaea (AOA) play crucial roles in marine carbon and nitrogen cycles by fixing inorganic carbon and performing the initial step of nitrification. Evaluation of carbon and nitrogen metabolism popularly relies on functional genes such as amoA and accA. Increasing studies suggest that quorum sensing (QS) mainly studied in biofilms for bacteria may serve as a universal communication and regulation mechanism among prokaryotes; however, this has yet to be demonstrated in marine planktonic archaea. To bridge this knowledge gap, we employed a combination of metabolic activity markers (amoA, accA, and grs) to elucidate the regulation of AOA-mediated nitrogen and carbon processes, including their interactions with the surrounding heterotrophic population. Through co-transcription investigations linking metabolic markers to potential key QS genes, we discovered that QS molecules could regulate AOA's carbon, nitrogen, and lipid metabolisms under different conditions. Interestingly, specific AOA ecotypes showed a preference for employing distinct QS systems and a distinct QS circuit involving typical population. Overall, our data demonstrate that QS orchestrates nitrogen and carbon metabolism, including the exchange of organic metabolites between AOA and surrounding heterotrophic bacteria. This aspect has been previously overlooked in marine AOA research.

Biography

Professor Dr. Chuanlun Zhang received his Ph.D. from Texas A&M University in 1994, worked as a postdoctoral fellow at the Oak Ridge National Laboratory from 1994 to 1998, taught as an assistant professor in the Department of Geology at University of Missouri from 1998 to 2002 and as an associate and full professor (tenured) at the University of Georgia from 2002 to 2014. He also served as a chair professor at the State Key Laboratory of Marine Geology in Tongji University in China from 2008 to 2012. He was invited to join the Southern University of Science and Technology of China in 2017 to lead a program in Microbial Oceanography and Geomicrobiology and serves as the vice chair of the Department of Ocean Science and Engineering.

Professor Zhang has been dedicating his career to biogeochemical and geomicrobiological research as well as student training for over 20 years. His research interests include the role that microorganisms play in the environment and energy transfer, life evolution and global climate change, and technology driven paradigm shift in ocean ecological research. His research strength lies in integration of lipid biomarkers, stable isotopes and molecular DNA to study microbial (particularly archaeal) activities in carbon and nitrogen cycles. Major research topics include, but are not limited to, geomicrobiology in ocean trenches, deep subsurface, hot springs and other extreme environments; biogeochemistry associated with marine gas hydrates; genomics of marine and terrestrial archaea; development and application of climate and environmental proxies; and applying drone array technologies for monitoring ocean environment change and collecting water samples for simultaneous examination of ecological changes across time and space.

Prof. Zhang has published over 300 peer-reviewed papers in international journals of earth and life sciences (eg. “Science”, “PNAS”, “Nature Ecol. Evol.”, “Mol. Biol. Evol.”, “Geology”, “Geochim. Cosmochim. Acta”, “ISME J”,“Environ. Microbiol.” ), with over 11830 citations and an H-index of 63 (Google Scholar). He was selected to be among the top 2% of global scientists for the years 2019 and 2020 and 2023.

Dr. Zhang is the Chief Editor for the Biology of Archaea specialty in Frontiers in Microbiology (FM) and on editorial boards for Archaea and SCIENCE CHINA Earth Sciences. In June of 2016, he was elected as the Vice Chair (2018) and Chair (2020) of the Gordon Research Conference on Ocean Biogeochemistry.

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