Marine Biological Association of the UK, The Laboratory, Citadel Hill, Plymouth, UK.
School of Biological and Marine Sciences, University of Plymouth, Plymouth, UK.
Biol Lett. 2020 Sep;16(9):20200368. doi: 10.1098/rsbl.2020.0368. Epub 2020 Sep 23.
Microbial colonization and degradation of particulate organic matter (POM) are important processes that influence the structure and function of aquatic ecosystems. Although POM is readily used by aquatic fungi and bacteria, there is a limited understanding of POM-associated interactions between these taxa, particularly for early-diverging fungal lineages. Using a model ecological system with the chitin-degrading freshwater chytrid fungus and chitin microbeads, we assessed the impacts of chytrid fungi on POM-associated bacteria. We show that the presence of chytrids on POM alters concomitant bacterial community diversity and structure, including differing responses between chytrid life stages. We propose that chytrids can act as ecosystem facilitators through saprotrophic feeding by producing 'public goods' from POM degradation that modify bacterial POM communities. This study suggests that chytrid fungi have complex ecological roles in aquatic POM degradation not previously considered, including the regulation of bacterial colonization, community succession and subsequent biogeochemical potential.
微生物对颗粒态有机物（POM）的定殖和降解是影响水生生态系统结构和功能的重要过程。尽管 POM 很容易被水生真菌和细菌利用，但对于早期分化的真菌类群，人们对 POM 相关的这些类群之间的相互作用的了解有限。本研究使用一种具有几丁质降解淡水壶菌和几丁质微珠的模型生态系统，评估了壶菌真菌对 POM 相关细菌的影响。研究结果表明，POM 上存在的壶菌会改变伴随的细菌群落多样性和结构，包括壶菌生活史阶段的不同反应。本研究提出，壶菌可以通过从 POM 降解中产生“公共产品”来进行腐生营养，从而改变细菌对 POM 的群落，以此作为生态系统的促进者。本研究表明，壶菌真菌在水生 POM 降解中具有复杂的生态作用，这是以前未被考虑的，包括对细菌定殖、群落演替和随后的生物地球化学潜力的调节。
