Molybdenum isotope signature of microbial nitrogen utilization in siboglinid tubeworms

Type Article
Date 2023-07
Language English
Author(s) Wang Xudong1, 2, Xu Ting3, Peckmann Jörn4, Bayon Germain5, Jia Zice1, Gong Shanggui1, Li Jie1, Cordes Erik6, Sun Yanan3, Tao Jun7, Chen Duofu1, Feng Dong1, 2
Affiliation(s) 1 : Shanghai Engineering Research Center of Hadal Science and Technology, College of Marine Sciences, Shanghai Ocean University, Shanghai 201306, China
2 : Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266061, China
3 : Department of Ocean Science, Division of Life Science, and Hong Kong Branch of the Southern Science and Engineering Guangdong Laboratory, The Hong Kong University of Science and Technology, Hong Kong, China
4 : Institute for Geology, Center for Earth System Research and Sustainability, Universität Hamburg, 20146 Hamburg, Germany
5 : Univ Brest, CNRS, Ifremer, Geo-Ocean, F-29280 Plouzané, France
6 : Department of Biology, Temple University, Philadelphia, Pennsylvania 19122, USA
7 : MLR Key Laboratory of Marine Mineral Resources, Guangzhou Marine Geological Survey, China Geological Survey, Guangzhou 510070, China
Source Geology (0091-7613) (Geological Society of America), 2023-07 , Vol. 51 , N. 7 , P. 698-702
DOI 10.1130/G51077.1

Many chemosynthesis-based communities prospering in deep-sea environments rely on the metabolic activity of sulfide-oxidizing bacteria. This is the case for vestimentiferan siboglinid tubeworms, whose demand for nutrition is satisfied predominantly by their endosymbiotic bacteria harbored in a specialized organ called the trophosome. Such chemosymbiosis leads to a significantly lower nitrogen isotope composition of the trophosome than in other types of soft tissue. However, the specific process of nitrogen utilization by siboglinids remains unclear. As a key element in the relevant enzymes (nitrogenase and nitrate reductase), molybdenum (Mo) is indispensable in the biogeochemical cycling of nitrogen. The Mo isotope composition (δ98Mo) of siboglinids is thus a potential proxy for decoding the processes involved in nitrogen metabolism. In this study, we found δ98Mo values along the chitinous tube of the vestimentiferan siboglinid Paraescarpia echinospica from the Haima seeps of the South China Sea as negative as −4.59‰ (−1.13‰ ± 1.75‰, 1SD, n = 19)—the lowest δ98Mo value ever reported for any kind of natural material. It is suggested that this extremely negative Mo isotope composition is caused by preferential utilization of isotopically light Mo by the tubeworm's endosymbionts or epibionts during nitrate reduction. Such Mo isotope signature could provide a means for identifying siboglinid tubeworms, a group of annelids that has previously escaped unambiguous identification due to the lack of mineralized skeleton, in the rock record.

Full Text
File Pages Size Access
Publisher's official version 5 1 MB Open access
Top of the page

How to cite 

Wang Xudong, Xu Ting, Peckmann Jörn, Bayon Germain, Jia Zice, Gong Shanggui, Li Jie, Cordes Erik, Sun Yanan, Tao Jun, Chen Duofu, Feng Dong (2023). Molybdenum isotope signature of microbial nitrogen utilization in siboglinid tubeworms. Geology, 51(7), 698-702. Publisher's official version : , Open Access version :