生态环境学报 ›› 2025, Vol. 34 ›› Issue (1): 99-107.DOI: 10.16258/j.cnki.1674-5906.2025.01.011

• 研究论文【环境科学】 • 上一篇    下一篇

趋磁细菌Magnetospirillum gryphiswaldense MSR-1对镉的生物吸附初步研究

曹振宇1,2(), 涂晨1,2, 刘颖1,2, 韩军超1,3, 邢倩雯1,4, 骆永明1,2,*   

  1. 1.土壤与农业可持续发展国家重点实验室（中国科学院南京土壤研究所），江苏 南京 210008
    2.中国科学院大学，北京 100049
    3.南京信息工程大学环境科学与工程学院，江苏 南京 210044
    4.湖南师范大学地理科学学院，湖南 长沙 410081
  • 收稿日期:2024-02-11 出版日期:2025-01-18 发布日期:2025-01-21
  • 通讯作者: * 骆永明。
  • 作者简介:曹振宇（1998年生），男，硕士研究生，研究方向为镉污染的生物修复技术。E-mail: caozhenyu21@mails.ucas.ac.cn
  • 基金资助:
    国家重点研发计划项目(2022YFD1700104);中国科学院南京土壤研究所“十四五”自主部署项目(ISSASIP2204);中国建筑生态环保工程研究中心(土壤修复技术与装备);中国建筑第八工程局有限公司项目(CSCEC-PT-009)

Preliminary Study on the Biosorption of Cadmium by Magnetospirillum gryphiswaldense MSR-1

CAO Zhenyu1,2(), TU Chen1,2, LIU Ying1,2, HAN Junchao1,3, XING Qianwen1,4, LUO Yongming1,2,*   

  1. 1. State Key Laboratory of Soil and Sustainable Agriculture (Institute of Soil Science, Chinese Academy of Sciences), Nanjing 210008, P. R. China
    2. University of Chinese Academy of Sciences, Beijing 100049, P. R. China
    3. School of Environmental Science and Engineering, Nanjing University of Information Science & Technology, Nanjing 210044, P. R. China
    4. School of Geographical Sciences, Hunan Normal University, Changsha 410081, P. R. China
  • Received:2024-02-11 Online:2025-01-18 Published:2025-01-21

RichHTML

PDF

摘要：

趋磁细菌由于其独有的趋磁运动能力，展现出成为新型可回收生物吸附材料的潜力。但有关趋磁细菌对Cd(Ⅱ) 的吸附去除应用研究仍非常有限，趋磁细菌对Cd(Ⅱ) 的吸附特征与机理尚不明确。选用趋磁细菌模式菌株Magnetospirillum gryphiswaldense MSR-1，采用扫描电子显微镜（SEM）对MSR-1吸附Cd(Ⅱ) 前后的形态进行了表征；通过批吸附实验研究了不同溶液pH值、Cd(Ⅱ) 初始浓度、细菌生物量和温度等反应条件对MSR-1吸附Cd(Ⅱ) 的影响；利用动力学模型、等温吸附模型模拟了吸附过程；采用傅里叶变换红外光谱（FTIR）、顺序洗脱法等方法初步探究了MSR-1对Cd(Ⅱ) 吸附的机理。结果表明，吸附Cd后的MSR-1菌体表面形貌改变并出现破损。MSR-1对Cd(Ⅱ) 的吸附效率主要受pH、初始Cd(Ⅱ) 浓度和细菌生物量等因素影响。当pH为8.0、Cd(Ⅱ) 初始浓度为1 mg·L−1、温度为30 ℃、吸附时间为1 h、细菌生物量（湿质量）为3.33 g·L−1时，MSR-1对Cd(Ⅱ) 的吸附效率可达87.8%。Cd(Ⅱ) 浓度在0.5—20 mg·L−1时，随着Cd(Ⅱ) 浓度的升高，MSR-1对Cd(Ⅱ) 的吸附量逐渐增大，最大吸附量达1.20 mg·g−1。MSR-1对Cd(Ⅱ)的吸附过程遵循准二级动力学方程和Langmuir等温模型。羟基、酰胺I基团和羧基等基团参与了MSR-1吸附Cd(Ⅱ) 的过程。MSR-1对Cd(Ⅱ) 吸附机制可涉及物理吸附、离子交换、络合作用和胞内积累，其中离子交换作用为最主要的吸附机制，贡献占比为74.9%。综上，趋磁细菌MSR-1对Cd(Ⅱ) 有较好的吸附去除能力，为未来作为有潜力的可回收生物吸附材料，用于Cd污染水体和土壤的生物修复提供数据支持和理论依据。

关键词: 趋磁细菌, 镉, 生物吸附作用, 离子交换, 影响因子

Abstract:

Addressing the challenge of environmental cadmium (Cd) pollution, microbial adsorption technology has emerged as a promising, cost-effective and eco-friendly method for Cd removal, drawing significant attention. However, the separation and recovery of microbial adsorbents from environmental media remains a challenge. In this regard, magnetotactic bacteria, leveraging their unique magnetotaxis capability, exhibit a promising capacity as recyclable bioadsorbents for Cd removal. Research on utilizing magnetotactic bacteria for Cd(II) removal remains limited, however, with the adsorption mechanisms of these bacteria for Cd(II) not yet fully understood. To address this gap, the model magnetotactic strain Magnetospirillum gryphiswaldense MSR-1 was selected for evaluation in this study. The morphology of MSR-1 before and after Cd(II) adsorption was characterized by utilizing scanning electron microscopy (SEM). Batch adsorption experiments were conducted to investigate the impact of pH, Cd(II) concentrations, microbial biomass and temperature on Cd(II) adsorption efficiency. Kinetic models and adsorption isotherm models were applied to elucidate the adsorption process. Additionally, Fourier transform infrared spectroscopy (FTIR) and sequential elution methods were utilized to delineate the adsorption mechanisms. Our findings revealed that elevated Cd(II) concentrations induced noticeable changes and damage to the surface of MSR-1 cells. Optimal adsorption conditions were determined as a pH of 8.0, a Cd(II) concentration of 1 mg·L−1, a temperature of 30 ℃, an adsorption duration of 1 hour, and a microbial biomass of 3.33 g·L−1 (wet weight), achieving an impressive Cd(II) adsorption efficiency of 87.8%. With increasing Cd(II) concentration from 0.5 to 20 mg·L−1, the adsorption capacity of MSR-1 exhibited a progressive increase, peaking at 1.20 mg·g−1. The adsorption kinetics of MSR-1 towards Cd(II) were accurately described by the pseudo-second-order kinetic model and the Langmuir isotherm model. Notably, functional groups including hydroxyl, amide I and carboxyl groups were involved in the adsorption process. The mechanism in Cd(II) adsorption by MSR-1 mainly includes physical adsorption, ion exchange, complexation and intracellular accumulation, with ion exchange being the dominant process, contributing to 74.9% of the process. In summary, the magnetotactic bacteria MSR-1 exhibits a notable adsorption capacity for Cd(II), providing data support and a theoretical basis for its future potential as a recyclable bioadsorbent material for the bioremediation of Cd-contaminated water and soil.

Key words: magnetotactic bacteria, cadmium, biosorption effect, ion exchange, factors

中图分类号: