Community differences and potential function along the particle size spectrum of microbes in the twilight zone

作者：Yue Zhang, Hongbin Liu, Hongmei Jing · 发表于：Microbiome · 年份：2025 · DOI：10.1186/s40168-025-02116-8 · 被引用次数：6 · 研究领域：Microbial Community Ecology and Physiology、Marine and coastal ecosystems、Methane Hydrates and Related Phenomena

BACKGROUND: The twilight zone, which extends from the base of the euphotic zone to a depth of 1000 m, is the major area of particulate organic carbon (POC) remineralization in the ocean. However, little is known about the microbial community and metabolic activity that are directly associated with POC remineralization in this consistently underexplored realm. Here, we utilized a large-volume in situ water transfer system to collect the microbes on different-sized particles from the twilight zone in three regions and analyzed their composition and metabolic function by metagenomic analysis. RESULTS: Distinct prokaryotic communities with significantly lower diversity and less endemic species were detected on particles in the South East Asian Time-series Study (SEATS) compared with the other two regions, perhaps due to the in situ physicochemical conditions and low labile nutrient availability in this region. Observable transitions in community composition and function at the upper and lower boundaries of the twilight zone suggest that microbes respond differently to (and potentially drive the transformation of) POC through this zone. Substantial variations among different particle sizes were observed, with smaller particles typically exhibiting lower diversity but harboring a greater abundance of carbon degradation-associated genes than the larger particles. Such a pattern might arise due to the relatively larger surface area of the smaller particles relative to their volume, w...