Li Yuqian, Chen Haomin, Li Wei, Xi Beidou, Huang Caihong
State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China.
J Hazard Mater. 2025 Mar 15;486:137144. doi: 10.1016/j.jhazmat.2025.137144. Epub 2025 Jan 6.
The remediation of sites co-contaminated with polycyclic aromatic hydrocarbons (PAHs) and heavy metals (HMs) poses challenges for efficient and ecofriendly restoration methods. In this study, three strains (Pseudomonas sp. PDC-1, Rhodococcus sp. RDC-1, and Enterobacter sp. EDC-1) were isolated from sites contaminated with PAHs and HMs. The constructed bacteria consortium was then immobilized using biochar, bentonite, and peat. The immobilized bacteria consortium (IBC) demonstrated efficient removal ability of phenanthrene (58.1 %-73.4 %) and benzo[a]pyrene (69.6 %-83.5 %) during 60 days. Additionally, the IBC decreased soil bacterial richness and diversity, but increased the relative abundance of Proteobacteria phylum and Ochrobactrum genus, which were capable of degrading PAHs. Soil microbial co-occurrence network with IBC was classified into three main modules, and 14 genera were identified as keystone taxa linked to PAHs degradation and HMs resistance. The IBC enhanced the dioxygenase metabolic pathways for PAHs degradation, including phthalic acid and salicylic acid pathways, which became the main driving factor affecting PAHs removal efficiency based on the structural equation modeling analysis. This study confirmed the potential application of the constructed IBC in the bioremediation of soil co-contaminated with PAHs-HMs, and provides insights into key removal mechanism and main driving factor of the enhanced elimination of PAHs.
多环芳烃（PAHs）和重金属（HMs）共同污染场地的修复对高效且环保的修复方法构成了挑战。在本研究中，从受PAHs和HMs污染的场地分离出三株菌株（假单胞菌属PDC-1、红球菌属RDC-1和肠杆菌属EDC-1）。然后使用生物炭、膨润土和泥炭固定构建的细菌联合体。固定化细菌联合体（IBC）在60天内对菲（58.1% - 73.4%）和苯并[a]芘（69.6% - 83.5%）表现出高效的去除能力。此外，IBC降低了土壤细菌的丰富度和多样性，但增加了能够降解PAHs的变形菌门和苍白杆菌属的相对丰度。与IBC相关的土壤微生物共现网络被分为三个主要模块，14个属被确定为与PAHs降解和HMs抗性相关的关键分类群。基于结构方程模型分析，IBC增强了PAHs降解的双加氧酶代谢途径，包括邻苯二甲酸和水杨酸途径，这成为影响PAHs去除效率的主要驱动因素。本研究证实了构建的IBC在PAHs-HMs共同污染土壤生物修复中的潜在应用，并为PAHs强化去除的关键去除机制和主要驱动因素提供了见解。
