Adsorption of Benzoapyrene Degrading Bacteria on Different Inorganic Mineral Colloids

Based on isothermal adsorption experiments, Ex-DLVO theory, Fourier transform infrared spectroscopy (FTIR) and other means were used to explore the interface interaction mechanism between typical soil colloids (kaolinite, montmorillonite and hematite) and Paracoccus aminovorans HPD-2, which is a highly efficient degrading bacteria of benzoapyrene. The results show that the isotherm adsorption curves of the three typical soil inorganic colloids on HPD-2 cells were all in accordance with Langmuir adsorption model, and the theoretical maximum adsorption capacity was hematite >> montmorillonite > kaolinite. The Ex-DLVO theory results show that the adsorption process of hematite on HPD-2 cells was spontaneous, while the adsorption of kaolinite and montmorillonite on degrading bacteria needed to cross the energy barrier. The electrostatic force between colloidal particles and cells played a key role in the adsorption process, which was much stronger than van der Waals force and hydrophobic force. FTIR results show that the interaction of kaolinite and montmorillonite on HPD-2 was mainly due to the change of protein configuration on cell surface, and the interaction was weak. In addition to hydrogen bond, strong P-OFe bond was formed between hematite and strain HPD-2. The results elucidate the mechanisms of interface interaction between inorganic mineral colloids with different properties and HPD-2 and can provide theoretical basis for the studies on the effect mechanism of inorganic colloids on the degrading microorganisms viability and colonization on their surface.