Marinimicrobia are widespread from the marine surface to the hadal zone. Major clades of Marinimicrobia have evolved to different ecotypes along with energy gradients, but their genomes in deeper waters and sediments have rarely been studied. Here we obtained 11 Marinimicrobia draft genomes from the water column in the full-ocean depth and the hadal sediments in the Mariana Trench. All the predicted genomic capabilities of the metagenome-assembled genomes (MAGs) are indicative of heterotrophic lifestyle. The MAGs from the hadal depths are distinct from those from the mesopelagic and bathypelagic depths by enrichment of the genes involved in amino acids metabolism and mismatch repair. Compared with the MAGs from waters, those from the sediments were dramatically expanded by acquiring the genes responsible for chemotaxis, mobility and the two-component systems. Marinimicrobia were apparently differentiated in the environments with different depths, organic matters and electronic acceptors. Our results also posit a potential evolutionary relationship between the species inhabiting the waters and sediments, indicating the occurrence of allopatric speciation in Marinimicrobia.

Marinimicrobia从海面到海底带广泛分布。Marinimicrobia的主要进化枝已随能量梯度演变成不同的生态类型，但在更深水域和沉积物中的基因组却很少被研究。在这里，我们从水柱中获得了11个Marinimicrobia草稿基因组，这些基因组位于整个海洋深度和Mariana海沟中的海生沉积物中。元基因组组装的基因组（MAGs）的所有预测的基因组能力都表明异养生活。通过丰富参与氨基酸代谢和错配修复的基因，来自海底深度的MAG与中，深海和深海的MAG截然不同。与来自水中的MAG相比，通过获取负责趋化性的基因，来自沉积物的MAG大大扩展了，移动性和两部分系统。Marinimicrobia在具有不同深度，有机物质和电子受体的环境中明显存在差异。我们的结果还提出了栖息在水域和沉积物中的物种之间潜在的进化关系，这表明马里尼微生物中发生了异源物种。