洋底深部极端环境硫酸盐还原真菌的发现及其异化硫酸盐还原机理和原位作用模拟研究

硫酸盐还原菌(SRM)在硫的生物地球化学循环中发挥极为重要的驱动作用。迄今报道的SRM全部为原核的细菌和古菌，未见硫酸盐还原真菌(SRF)的报道。我们近期研究惊奇发现，一些定居于洋底深部沉积物的古老真菌能够进行厌氧硫酸盐还原产硫化氢，但尚不完全清楚该环境的SRF类群及其异化硫酸盐还原机理和在原位环境硫循环中的作用。本项目拟利用我们已获得的洋底深部环境真菌为材料，采用同位素示踪等方法，发现并确证SRF种类；利用多维组学及基因编辑等技术，研究和发现SRF的异化硫酸盐还原机理及其特点；模拟原位条件培养含SRF的洋底沉积样品，探究和了解SRF在洋底深部极端环境硫循环中的作用。该项目的实施，不仅能够发现新的硫酸盐还原微生物类群、新的硫酸盐还原途径及其遗传基础，并有望从新的角度诠释真菌在洋底极端环境中的生存机理，为研究元素生物地球化学循环的驱动机理开启一个新方向。

Sulfate reducing bacteria (SRM) play an important driving role in the biogeochemical cycle of sulfur. So far, all SRMs have been reported to be bacteria and archaea of prokaryotes, and no sulfate-reducing fungi (SRF) have been reported. Our recent research has surprisingly revealed that some ancient fungi that inhabited in deep subseafloor sediments are able to perform anaerobic sulfate reduction to produce hydrogen sulfide. However, it is not clear about the species and mechanism of dissimilatory sulfate reduction of SRF and their roles in sulfur cycle in the in-situ environment. This project intends to discover and prove SRF species from our collected fungal species with isotope tracer techniques. The mechanism and characteristics of SRF will be studied and disclosed using multidimensional omics and gene editing techniques. The subseafloor sediment samples containing SRF will be cultivated under simulated in-situ conditions to explore and understand the role of SRF in sulfur cycle in deep subseafloor environments. The implementation of this project can not only discover new sulfate-reducing microbial groups, novel sulfate-reducing pathways and their genetic basis, but also be expected to interpret the survival mechanism of fungi in the extreme subseafloor environment from a new perspective, so as to open a new direction for the study of the driving mechanism of element biogeochemical cycle.