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Chemolithotrophic biosynthesis of organic carbon associated with volcanic ash in the Mariana Trough, Pacific Ocean

2023; Nature Portfolio; Volume: 4; Issue: 1 Linguagem: Inglês

10.1038/s43247-023-00732-6

2662-4435

Taisi Li, Jiwei Li, Jack Longman, Zhe‐Xuan Zhang, Yuangao Qu, Shun Chen, Shijie Bai, S. Dasgupta, Henchao Xu, Kaiwen Ta, Shuangquan Liu, Xiaotong Peng,

Microbial Community Ecology and Physiology

Abstract Volcanic ash is a major component of marine sediment, but its effect on the deep-sea carbon cycle remains enigmatic. Here, we analyzed mineralogical compositions and glycerol dialkyl glycerol tetraether (GDGT) membrane lipids in submarine tuffs from the Mariana Trough, demonstrating a fraction of organic carbon associated with volcanic ash is produced in situ. This likely derives from chemolithotrophic communities supported by alteration of volcanic material. Tuff GDGTs are characterized by enrichment of branched GDGTs, as in chemolithotrophic communities. Scanning electron microscope, Raman spectrum and nano secondary ion mass spectrometry analysis demonstrates organic carbon exists around secondary heamatite veins in the altered mafic minerals, linking mineral alteration to chemolithotrophic biosynthesis. We estimate organic carbon production of between 0.7 − 3.7 × 10 11 g if all the chemical energy produced by ash alteration was fully utilized by microorganisms. Therefore, the chemolithotrophic ecosystem maintained by ash alteration likely contributes considerably to organic carbon production in the seafloor.