Wu Ping, Rane Niraj R, Xing Chao, Patil Swapnil M, Roh Hyun-Seog, Jeon Byong-Hun, Li Xiaofang
Hebei Key Laboratory of Soil Ecology, Center for Agricultural Resources Research, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Shijiazhuang 050021, China.
Department of Earth Resources and Environmental Engineering, Hanyang University, Seoul 04763, Republic of Korea.
J Hazard Mater. 2022 Aug 5;435:129002. doi: 10.1016/j.jhazmat.2022.129002. Epub 2022 Apr 26.
A comprehensive understanding of the cellular response of microbes to metal stress is necessary for the rational development of microbe-based biosorbents for metal removal. The present study investigated the copper (Cu) sorption and resistance mechanism of Bacillus cereus strain T6, a newly isolated Cu-resistant bacterium, by integrative analyses of physiochemistry, genomics, transcriptomics, and metabolomics. The growth inhibition assay and biosorption determination showed that this bacterium exhibited high tolerance to Cu, with a minimum inhibitory concentration of 4.0 mM, and accumulated Cu by both extracellular adsorption and intracellular binding. SEM microscopic images and FTIR spectra showed significant cellular surface changes at the high Cu level but not at low, and the involvement of surface functional groups in the biosorption of Cu, respectively. Transcriptomic and untargeted metabolomic analyses detected 362 differentially expressed genes and 60 significantly altered metabolites, respectively. Integrative omics analyses revealed that Cu exposure dramatically induced a broad spectrum of genes involved in Cu transport and iron homeostasis, and suppressed the denitrification pathway, leading to significant accumulation of metabolites for metal transporter synthesis, membrane remolding, and antioxidant activities. The results presented here provide a new perspective on the intricate regulatory network of Cu homeostasis in bacteria.
全面了解微生物对金属胁迫的细胞反应对于合理开发用于金属去除的微生物基生物吸附剂至关重要。本研究通过对生理化学、基因组学、转录组学和代谢组学的综合分析，研究了新分离的耐铜细菌蜡样芽孢杆菌T6菌株对铜（Cu）的吸附和抗性机制。生长抑制试验和生物吸附测定表明，该细菌对铜具有高耐受性，最低抑菌浓度为4.0 mM，并通过细胞外吸附和细胞内结合积累铜。扫描电子显微镜图像和傅里叶变换红外光谱分别显示了在高铜水平下细胞表面的显著变化以及表面官能团参与铜的生物吸附。转录组学和非靶向代谢组学分析分别检测到362个差异表达基因和60种显著改变的代谢物。综合组学分析表明，铜暴露显著诱导了一系列参与铜转运和铁稳态的基因，并抑制了反硝化途径，导致参与金属转运蛋白合成、膜重塑和抗氧化活性的代谢物显著积累。本文的结果为细菌中铜稳态的复杂调控网络提供了新的视角。
