Li Qianqian, Cooper Rebecca E, Wegner Carl-Eric, Küsel Kirsten
Institute of Biodiversity, Friedrich Schiller University Jena, 07743 Jena, Germany.
The German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, 04103 Leipzig, Germany.
Microorganisms. 2020 Feb 25;8(3):314. doi: 10.3390/microorganisms8030314.
Iron-rich pelagic aggregates (iron snow) are hot spots for microbial interactions. Using iron snow isolates, we previously demonstrated that the iron-oxidizer sp. C25 triggers sp. C61 aggregation by producing the infochemical 2-phenethylamine (PEA). Here, we showed slightly enhanced aggregate formation in the presence of PEA on different spp. but not other iron-snow microorganisms, including sp. C78 and sp. PN-J47. Next, we sequenced the sp. C61 genome to reconstruct its metabolic potential. Pangenome analyses of spp. genomes revealed the core genome contained 65 gene clusters associated with aggregation, including autoaggregation, motility, and biofilm formation. Screening the sp. C61 genome revealed the presence of autotransporter, flagellar, and extracellular polymeric substances (EPS) production genes. RNA-seq analyses of sp. C61 incubations (+/- 10 µM PEA) indicated genes involved in energy production, respiration, and genetic processing were the most upregulated differentially expressed genes in the presence of PEA. Additionally, genes involved in flagellar basal body synthesis were highly upregulated, whereas the expression pattern of biofilm formation-related genes was inconclusive. Our data shows aggregation is a common trait among spp. and PEA stimulates the central cellular metabolism, potentially advantageous in aggregates rapidly falling through the water column.
富含铁的远洋聚集体（铁雪）是微生物相互作用的热点。利用铁雪分离株，我们之前证明了铁氧化菌sp. C25通过产生信息化学物质2-苯乙胺（PEA）触发sp. C61聚集。在这里，我们发现，在PEA存在的情况下，不同菌株的聚集体形成略有增强，但包括sp. C78和sp. PN-J47在内的其他铁雪微生物则没有。接下来，我们对sp. C61基因组进行测序，以重建其代谢潜力。对多个菌株基因组的泛基因组分析表明，核心基因组包含65个与聚集相关的基因簇，包括自聚集、运动性和生物膜形成。对sp. C61基因组的筛选揭示了自转运蛋白、鞭毛和细胞外聚合物（EPS）产生基因的存在。对sp. C61培养物（±10 µM PEA）的RNA测序分析表明，在PEA存在的情况下，参与能量产生、呼吸和基因加工的基因是上调最明显的差异表达基因。此外，参与鞭毛基体合成的基因高度上调，而生物膜形成相关基因的表达模式尚无定论。我们的数据表明，聚集是多个菌株的共同特征，PEA刺激细胞的核心代谢，这在聚集体快速穿过水柱时可能具有优势。
