Structural and functional characteristics of archaeal community on carbonatite surface weathered for different time

Abstract:

[Background] Archaea, the pioneer on the surface of carbonatite, promote the chemical weathering of carbonatite and the formation of soil and play an essential part in biogeochemical process of elements. [Objective] To reveal the structure and ecological functions of the archaeal community on the carbonatite surface weathered for different time.[Methods] A total of 18 samples were collected from the surface of abandoned carbonatite tombstones (weathered for 19-213 years) in Huaxi District, Guizhou Province, and the structural and functional characteristics of archaeal community were analyzed by metagenomic sequencing. [Results] The dominant archaeal phylum was Euryarchaeota, followed by Thaumarchaeota, unclassified Archaea, Bathyarchaeota, and Crenarchaeota. At the genus level, Methanosarcina, Methanothrix, Methanoperedens,Nitrosocosmicus, Nitrososphaera and others unidentified genera were dominant. C/N, C/P and N/P were the main environmental factors that significantly affected the archaeal community on the carbonatite surface. In addition, archaeal community on the surface of carbonatite had diverse functions, particularly metabolism. Euryarchaeota and Thaumarchaeota were the dominant functional groups in the cycling of C, N, and S. The weathering degree of carbonatite significantly increased and the relative abundance of Euryarchaeota and Crenarchaeota obviously decreased over time. Moreover, the relative abundance of Thaumarchaeota had no significant change over time. [Conclusion] In summary, we believed that the survival strategy of the archaeal community changed from an r-strategy (Euryarchaeota) to a K-strategy (Thaumarchaeota) with the weathering.