School of Life Sciences, School of Marine Science and Engineering, Nanjing Normal University, Nanjing 210023, China.
School of Life Sciences, School of Marine Science and Engineering, Nanjing Normal University, Nanjing 210023, China; School of Life Sciences, Key Laboratory of Agricultural Environmental Pollution Prevention and Control in Red Soil Hilly Region of Jiangxi Province, Jinggangshan University, Ji'an 343009, China.
Sci Total Environ. 2022 Feb 1;806(Pt 4):150911. doi: 10.1016/j.scitotenv.2021.150911. Epub 2021 Oct 12.
Cadmium (Cd) pollution is a pressing environmental issue that must be addressed. In recent years, microbial mineralization biotechnology has been developed into an effective and eco-friendly heavy metal bioremediation solution. In the present research, RNA-Seq technology was utilized to reveal the molecular mechanism through which Bacillus velezensis LB002 induced the mineralization and Cd fixation under high-concentration Cd stress. The metabolic pathways involved in the genes that were significant differentially expressed in the process of bacterial mineralization were also investigated. The results showed that the physiological response of bacteria to Cd toxicity may include bacterial chemotaxis, siderophore complexation, and transport across cell membranes. Bacteria subjected to high-concentration Cd stress can up-regulate genes of argH, argF, hutU, hutH, lpdA, and acnA related to arginine synthesis, histidine metabolism, and citric acid cycle metabolism pathways, inducing vaterite formation and Cd fixation. Thus, the toxicity of Cd was decreased and bacteria were allowed to grow. Real-time quantitative polymerase chain reaction (RT-qPCR) results confirmed the data obtained by RNA-Seq, indicating that bacteria can reduce Cd toxicity by regulating the expression of related genes to induce mineralization. A basic bioremediation strategy to deal with high-concentration heavy-metal pollution was proposed from the perspective of gene regulation.
镉（Cd）污染是一个亟待解决的环境问题。近年来，微生物矿化生物技术已发展成为一种有效且环保的重金属生物修复解决方案。本研究利用 RNA-Seq 技术揭示了在高浓度 Cd 胁迫下，解淀粉芽孢杆菌 LB002 诱导矿化和 Cd 固定的分子机制，并研究了细菌矿化过程中显著差异表达基因所涉及的代谢途径。结果表明，细菌对 Cd 毒性的生理响应可能包括细菌趋化性、铁载体络合和跨细胞膜运输。处于高浓度 Cd 胁迫下的细菌可以上调与精氨酸合成、组氨酸代谢和柠檬酸循环代谢途径相关的 argH、argF、hutU、hutH、lpdA 和 acnA 基因，诱导方解石的形成和 Cd 固定。从而降低 Cd 的毒性，使细菌得以生长。实时定量聚合酶链反应（RT-qPCR）结果证实了 RNA-Seq 获得的数据，表明细菌可以通过调节相关基因的表达来诱导矿化，从而降低 Cd 的毒性。从基因调控的角度提出了一种基本的生物修复策略来处理高浓度重金属污染。
