Kim Hiyoung, Ahn Jiyeong, Kim Jaebum, Kang Hahk-Soo
Department of Biomedical Science and Engineering, Konkuk University, Seoul, South Korea.
Microbiol Spectr. 2025 Jan 7;13(1):e0235524. doi: 10.1128/spectrum.02355-24. Epub 2024 Nov 22.
Korea, being surrounded by the sea, provides a rich habitat for marine sponges, which have been a prolific source of bioactive natural products. Although a diverse array of structurally novel natural products has been isolated from Korean marine sponges, their biosynthetic origins remain largely unknown. To explore the biosynthetic potential of Korean marine sponges, we conducted metagenomic analyses of sponges inhabiting the East Sea of Korea. This analysis revealed a symbiotic association of Entotheonella bacteria with Halichondria sponges. Here, we report a new chemically rich Entotheonella variant, which we named . Entotheonella halido. Remarkably, this symbiont makes up 69% of the microbial community in the sponge . Genome-resolved metagenomics enabled us to obtain a high-quality . E. halido genome, which represents the largest (12 Mb) and highest quality among previously reported genomes. We also identified the biosynthetic gene cluster (BGC) of the known sponge-derived Halicylindramides from the . E. halido genome, enabling us to determine their biosynthetic origin. This new symbiotic association expands the host diversity and biosynthetic potential of metabolically talented bacterial genus . Entotheonella symbionts.IMPORTANCEOur study reports the discovery of a new bacterial symbiont . Entotheonella halido associated with the Korean marine sponge . Using genome-resolved metagenomics, we recovered a high-quality . E. halido MAG (Metagenome-Assembled Genome), which represents the largest and most complete . Entotheonella MAG reported to date. Pangenome and BGC network analyses revealed a remarkably high BGC diversity within the . Entotheonella pangenome, with almost no overlapping BGCs between different MAGs. The cryptic and genetically unique BGCs present in the . Entotheonella pangenome represents a promising source of new bioactive natural products.
韩国四面环海，为海洋海绵提供了丰富的栖息地，而海洋海绵一直是生物活性天然产物的丰富来源。尽管从韩国海洋海绵中分离出了各种各样结构新颖的天然产物，但它们的生物合成起源在很大程度上仍不为人知。为了探索韩国海洋海绵的生物合成潜力，我们对栖息在韩国东海的海绵进行了宏基因组分析。该分析揭示了Entotheonella细菌与Halichondria海绵的共生关系。在此，我们报告了一种新的富含化学物质的Entotheonella变体，我们将其命名为Entotheonella halido。值得注意的是，这种共生体占海绵微生物群落的69%。基因组解析宏基因组学使我们能够获得高质量的E. halido基因组，它是先前报道的基因组中最大（12 Mb）且质量最高的。我们还从E. halido基因组中鉴定出了已知海绵衍生的Halicylindramides的生物合成基因簇（BGC），从而能够确定它们的生物合成起源。这种新的共生关系扩展了具有代谢天赋的细菌属Entotheonella共生体的宿主多样性和生物合成潜力。
重要性
我们的研究报告了与韩国海洋海绵相关的新细菌共生体Entotheonella halido的发现。通过基因组解析宏基因组学，我们获得了高质量的E. halido宏基因组组装基因组（MAG），它是迄今为止报道的最大且最完整的Entotheonella MAG。泛基因组和BGC网络分析揭示了Entotheonella泛基因组内显著高的BGC多样性，不同MAG之间几乎没有重叠的BGC。Entotheonella泛基因组中存在的隐秘且遗传独特的BGC代表了新生物活性天然产物的一个有前景的来源。
