Centre for Marine Science and Innovation, School of Biological, Earth and Environmental Sciences, Faculty of Science, The University of New South Wales, Kensington, NSW 2052, Australia.
Universidade Federal do Rio de Janeiro, Instituto de Biologia, Departamento de Microbiologia Paulo de Goes, LEMM Laboratory, 21941-902, Rio de Janeiro, Brazil.
ISME J. 2024 Jan 8;18(1). doi: 10.1093/ismejo/wrae197.
The basal metazoan phylum Porifera (sponges) is increasingly used as a model to investigate ecological and evolutionary features of microbe-animal symbioses. However, sponges often host complex microbiomes, which has hampered our understanding of their interactions with their microbial symbionts. Here, we describe the discovery and characterization of the simplest sponge holobiont reported to date, consisting of the deep-sea glass sponge Aphrocallistes beatrix and two newly-described microbial symbionts: an autotrophic ammonia-oxidizing archaeon and a bacterial heterotroph. Omics analyses and metabolic modeling revealed the dependency of the ammonia-oxidizing archaea on sponge-derived ammonia to drive primary production, which in turn supports the bacterium's growth by providing the dicarboxylate fumarate. Furthermore, virus-mediated archaeal lysis appears crucial to overcome the bacterium's vitamin B12 auxotrophy. These findings reveal that the exchanges of vitamin B12 and dicarboxylate may be evolutionarily conserved features of symbiosis as they can also be found in interactions between free-living marine bacteria, and between microbes and plants or diatoms.
后生动物门多孔动物（海绵动物）越来越多地被用作研究微生物-动物共生体的生态和进化特征的模型。然而，海绵通常宿主复杂的微生物组，这阻碍了我们对其与微生物共生体相互作用的理解。在这里，我们描述了迄今为止报道的最简单海绵共生体的发现和特征，该共生体由深海玻璃海绵 Aphrocallistes beatrix 和两种新描述的微生物共生体组成：自养氨氧化古菌和细菌异养生物。组学分析和代谢建模揭示了氨氧化古菌对海绵衍生氨的依赖性，以驱动初级生产，这反过来又通过提供二羧酸延胡索酸来支持细菌的生长。此外，病毒介导的古菌裂解似乎对克服细菌的维生素 B12 营养缺陷至关重要。这些发现表明，维生素 B12 和二羧酸的交换可能是共生进化保守的特征，因为它们也可以在自由生活的海洋细菌之间的相互作用，以及在微生物与植物或硅藻之间的相互作用中找到。
