compost metagenome Raw sequence reads. compost metagenome

Humic substances (HS) could be utilized by humic reducing microorganisms (HRMs) as terminal acceptors. They can accept/donate electrons and greatly affect the redox conversion of inorganic and organic pollutants under reducing conditions. However, the response of HRMs to the electron transfer capacities (ETC) of HS remains poorly understood. Here, we assessed the response of HRMs to the accepting and donating capacities of humic and fulvic acids during seven compostings at three phases. We foundThe results showed that the electron accepting capacity and electron donating capacity of HS were notdidn’t increasedincrease along with the composting process, whileand it showed a significant correlation to with the aromaticity, carboxylic C content and the molecular weight of HS. Composting increased the abundance and diversity of the HRMs. 11 key HRMs were found significantly influenced the ETC-related composition and structures of HS. According to the relationships between the key HRMs and environmental parameters, a regulating method to enhance the ETC of HS was proposed.

腐殖物质（HS）可被腐殖质还原微生物（HRMs）用作末端电子受体。这类物质既能够接受也能够供出电子，在还原环境下对无机与有机污染物的氧化还原转化过程产生显著影响。然而，目前学界对腐殖质还原微生物响应腐殖物质电子转移能力（ETC）的机制仍缺乏深入认知。

本研究针对覆盖三个堆肥阶段的七次堆肥过程，评估了腐殖质还原微生物对腐殖酸与富里酸的电子接受能力及电子供出能力的响应情况。研究结果显示，腐殖物质的电子接受能力与电子供出能力并未随堆肥进程提升，反而与腐殖物质的芳香性、羧基碳含量及分子量呈现显著相关性。堆肥过程提升了腐殖质还原微生物的丰度与多样性。本研究共鉴定出11株关键腐殖质还原微生物，它们可显著影响与电子转移能力相关的腐殖物质组成及结构特征。基于关键腐殖质还原微生物与环境参数间的关联关系，本研究提出了一种提升腐殖物质电子转移能力的调控方法。