Li Yunshi, Niu Haoyuan, Li Shuang, Yue Ming, Zhang Gaosen
Key Laboratory of Resource Biology and Biotechnology in Western China, Xi'an 710069, China.
Department of Life Science, Northwest University, Xi'an 710069, China.
Microorganisms. 2024 Dec 18;12(12):2620. doi: 10.3390/microorganisms12122620.
Microbial adsorption is a cost-effective and environmentally friendly remediation method for heavy metal pollution. The adsorption mechanism of cadmium (Cd) by bacteria inhabiting extreme environments is largely unexplored. This study describes the biosorption of Cd by sp. M1-B02, which was isolated from the moraine on the north slope of Mount Everest and has a good potential for biosorption. The difference in Cd adsorption of the strain after UV irradiation stimulation indicated that the adsorption reached 68.90% in 24 h, but the adsorption after UV irradiation increased to 80.56%. The genome of strain M1-B02 contained antioxidant genes such as , , , and heavy metal repair genes such as RS14805, , . Hydroxyl, nitro, and etceteras bonds on the bacterial surface were involved in Cd adsorption through complexation reactions. The metabolites of the strains were significantly different after 24 h of Cd stress, with pyocyanin, L-proline, hypoxanthine, etc., being downregulated and presumably involved in Cd biosorption and upregulated after UV-C irradiation, which may explain the increase in Cd adsorption capacity of the strain after UV-C irradiation, while the strain improved the metabolism of the antioxidant metabolite carnosine, indirectly increasing the adsorption capacity of the strains for Cd.
微生物吸附是一种具有成本效益且环境友好的重金属污染修复方法。栖息于极端环境中的细菌对镉（Cd）的吸附机制在很大程度上尚未得到探索。本研究描述了从珠穆朗玛峰北坡冰碛中分离出的菌株sp. M1 - B02对Cd的生物吸附情况，该菌株具有良好的生物吸附潜力。紫外线照射刺激后该菌株对Cd的吸附差异表明，未照射时24小时内吸附率达68.90%，但紫外线照射后的吸附率增至80.56%。菌株M1 - B02的基因组包含抗氧化基因如 、 、 以及重金属修复基因如RS14805、 、 。细菌表面的羟基、硝基等键通过络合反应参与Cd吸附。Cd胁迫24小时后菌株的代谢产物有显著差异，绿脓菌素、L - 脯氨酸、次黄嘌呤等下调，推测参与Cd生物吸附，紫外线C照射后上调，这可能解释了紫外线C照射后菌株Cd吸附能力的增加，同时该菌株改善了抗氧化代谢物肌肽的代谢，间接增加了菌株对Cd的吸附能力。
