Abstract：
Dimethylsulfoniopropionate (DMSP), a key organic sulfur compound in marine and subseafloor sediments, is degraded by phytoplankton and bacteria, resulting in the release of the climate-active volatile gas dimethylsulfide (DMS). However, it remains unclear if dominant eukaryotic fungi in subseafloor sediments possess specific abilities and metabolic mechanisms for DMSP degradation and DMS formation. Our study provides the first evidence that fungi from coal-bearing sediments ∼2 km below the seafloor, such as Aspergillus spp., Chaetomium globosum, Cladosporium sphaerospermum, and Penicillium funiculosum, can degrade DMSP and produce DMS. In Aspergillus sydowii 29R-4-F02, which exhibited the highest DMSP-dependent DMS production rate (16.95 pmol/μg protein/min), two DMSP lyase genes, dddP and dddW, were identified. Remarkably, the dddW gene, previously observed only in bacteria, was found to be crucial for fungal DMSP cleavage. These findings not only extend the list of fungi capable of degrading DMSP, but also enhance our understanding of DMSP lyase diversity and the role of fungi in DMSP decomposition in subseafloor sedimentary ecosystems.
摘要：
二甲基磺丙酸酯（DMSP），海洋和海底沉积物中的一种关键有机硫化合物，被浮游植物和细菌降解，导致气候活性挥发性气体二甲基硫醚（DMS）的释放。然而,目前尚不清楚海底沉积物中的优势真核真菌是否具有DMSP降解和DMS形成的特定能力和代谢机制。我们的研究提供了第一个证据，即海底以下约2公里的含煤沉积物中的真菌，如曲霉属。,球形毛壳，sphaerospermum枝孢霉,和青霉，可以降解DMSP并产生DMS。在sydowii曲霉29R-4-F02中，表现出最高的DMSP依赖性DMS生产率（16.95pmol/μg蛋白/min），两个DMSP裂解酶基因，dddP和ddW，已确定。值得注意的是,dddW基因,以前只在细菌中观察到，发现对真菌DMSP裂解至关重要。这些发现不仅扩展了能够降解DMSP的真菌名单，而且还增强了我们对海底沉积生态系统中DMSP裂解酶多样性以及真菌在DMSP分解中的作用的理解。
