Interaction of Pseudomonas putida with kaolinite and montmorillonite: a combination study by equilibrium adsorption, ITC, SEM and FTIR.
Interaction of Pseudomonas putida with kaolinite and montmorillonite: a combination study by equilibrium adsorption, ITC, SEM and FTIR.
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DOI：
10.1016/j.colsurfb.2008.01.008
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发表时间：
2008-06
期刊：
影响因子：
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通讯作者：
Xingmin Rong;Qiaoyun Huang;Xiao-min He;Hao Chen;P. Cai;W. Liang
中科院分区：
文献类型：
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作者：
Xingmin Rong;Qiaoyun Huang;Xiao-min He;Hao Chen;P. Cai;W. Liang
采用平衡吸附等温滴定量热法(ITC)、傅里叶变换红外光谱(FTIR)和扫描电子显微镜(SEM)技术研究恶臭假单胞菌在高岭石和蒙脱石上的吸附。恶臭假单胞菌在高岭石上具有较高的亲和力和较大的吸附量。大部分被吸附的细菌细胞(88.7%)可以被水从蒙脱石中释放出来，而细菌只有一小部分(9.3%)从高岭石表面解吸。细菌细胞较多地与高岭石形成聚集体，而较大的细菌-蒙脱石颗粒内的细胞较少。细菌在高岭石上的吸附比在蒙脱石上更有利于吸附。根据我们的发现，非静电力在高岭石和蒙脱石对细菌的吸附中起着比静电力更重要的作用。细菌在粘土矿物上的吸附使水分子的红外吸收带发生了明显的移动，说明了细菌-粘土矿物吸附过程中氢键的重要性。本文首次报道了25℃、pH 7.0时，高岭石和蒙脱石对细菌的吸附热分别为−4.1±2.1×10−8和−2.5±1.4×10−8mJ−1。细菌-矿物相互作用的吸附热高于已报道的细菌-生物分子相互作用的吸附热值，但低于细菌共聚体的吸附热值。细菌-矿物的吸附热随温度的升高而增大，提示恶臭假单胞菌在粘土矿物上的吸附可能涉及焓-熵补偿机制。这项研究获得的数据将为更好地理解土壤和相关环境中矿物-微生物相互作用的机制提供有价值的信息。
Equilibrium adsorption along with isothermal titration calorimetry (ITC), Fourier transform infrared spectra (FTIR) and scanning electron microscopy (SEM) techniques were employed to investigate the adsorption of Pseudomonas putida on kaolinite and montmorillonite. A higher affinity as well as larger amounts of adsorption of P. putida was found on kaolinite. The majority of sorbed bacterial cells (88.7%) could be released by water from montmorillonite, while only a small proportion (9.3%) of bacteria desorbed from kaolinite surface. More bacterial cells were observed to form aggregates with kaolinite, while fewer cells were within the larger bacteria–montmorillonite particles. The sorption of bacteria on kaolinite was enthalpically more favorable than that on montmorillonite. Based on our findings, it is proposed that the non-electrostatic forces other than electrostatic force play a more important role in bacterial adsorption by kaolinite and montmorillonite. Adsorption of bacteria on clay minerals resulted in obvious shifts of infrared absorption bands of water molecules, showing the importance of hydrogen bonding in bacteria–clay mineral adsorption. The enthalpies of −4.1±2.1×10−8and −2.5±1.4×10−8mJcell−1for the adsorption of bacteria on kaolinite and montmorillonite, respectively, at 25°C and pH 7.0 were firstly reported in this paper. The enthalpy of bacteria–mineral adsorption was higher than that reported previously for bacteria–biomolecule interaction but lower than that of bacterial coaggregation. The bacteria–mineral adsorption enthalpies increased at higher temperature, suggesting that the enthalpy–entropy compensation mechanism could be involved in the adsorption of P. putida on clay minerals. Data obtained in this study would provide valuable information for a better understanding of the mechanisms of mineral–microorganism interactions in soil and associated environments.