MOE Laboratory of Biosystem Homeostasis and Protection, College of Life Sciences, Zhejiang University, Hangzhou, China.
Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou, China.
Environ Pollut. 2022 Aug 1;306:119362. doi: 10.1016/j.envpol.2022.119362. Epub 2022 Apr 27.
Co-contamination of organic pollutants and heavy metals is universal in the natural environment. Dibutyl phthalate (DBP), a typical plasticizer, frequently coexists with cadmium (Cd) in nature. However, little attention has been given to the impacts of co-contamination by DBP and Cd on microbial communities or the responses of microbes. To address this, a microcosm experiment was conducted by supplying the exogenous DBP-degrading bacterium Glutamicibacter nicotianae ZM05 to investigate the interplay among DBP-Cd co-contamination, the exogenous DBP-degrading bacterium G. nicotianae ZM05, and indigenous microorganisms. To adapt to co-contamination stress, microbial communities adjust their diversity, interactions, and functions. The stability of the microbial community decreased under co-contamination, as evidenced by lower diversity, simpler network, and fewer ecological niches. Microbial interactions were strengthened, as evidenced by enriched pathways related to microbial communications. Meanwhile, interactions between microorganisms enhanced the environmental fitness of the exogenous DBP-degrading bacterium ZM05. Based on co-occurrence network prediction and coculture experiments, metabolic interactions between the non-DBP-degrading bacterium Cupriavidus metallidurans ZM16 and ZM05 were proven. Strain ZM16 utilized protocatechuic acid, a DBP downstream metabolite, to relieve acid inhibition and adsorbed Cd to relieve toxic stress. These findings help to explain the responses of bacterial and fungal communities to DBP-Cd co-contamination and provide new insights for the construction of degrading consortia for bioremediation.
有机污染物和重金属的共污染在自然环境中普遍存在。邻苯二甲酸二丁酯（DBP）是一种典型的增塑剂，在自然界中经常与镉（Cd）共存。然而，人们对 DBP 和 Cd 的共污染对微生物群落的影响以及微生物的反应关注甚少。为了解决这个问题，通过提供外源性 DBP 降解菌谷氨酸棒杆菌 ZM05 进行了一个微宇宙实验，以研究 DBP-Cd 共污染、外源性 DBP 降解菌 G. nicotianae ZM05 和土著微生物之间的相互作用。为了适应共污染压力，微生物群落调整其多样性、相互作用和功能。共污染下微生物群落的稳定性下降，表现为多样性降低、网络简化和生态位减少。微生物相互作用增强，证据是与微生物通信相关的途径得到了富集。同时，微生物之间的相互作用增强了外源性 DBP 降解菌 ZM05 的环境适应性。基于共现网络预测和共培养实验，证明了非 DBP 降解菌铜绿假单胞菌 ZM16 和 ZM05 之间存在代谢相互作用。菌株 ZM16 利用 DBP 的下游代谢物原儿茶酸来缓解酸抑制，并吸附 Cd 以缓解毒性胁迫。这些发现有助于解释细菌和真菌群落对 DBP-Cd 共污染的响应，并为生物修复中降解菌联合体的构建提供新的见解。
