Abstract
Bacterial contact leaching of ores is more effective than non-contact leaching. Adhesion is the first step for leaching bacteria to form a biofilm on a mineral surface. Extracellular polymeric substances (EPS) are pivotal for mediating bacterial adhesion to a substratum. In order to clarify the role of EPS, we measured the adhesion forces between chalcopyrite-, sulfur- or FeSO4·7H2O-grown cells of Acidithiobacillus ferrooxidans and chalcopyrite by an atomic force microscope (AFM) before and after EPS removal. Surface properties of these cells were assessed by measurements of the contact angle, zeta potential, Fourier transform infrared spectroscopy (FTIR) and acid-base titration. Bacterial attachment to chalcopyrite was monitored for 140 min. The results indicate that the EPS control the surface properties of the cells. In addition, the surface properties are decisive for adhesion. The adhesion forces and the amounts of attached cells decreased dramatically after removing EPS, which was not dependent on the preculture.
Highlights
Understanding bacterial attachment to mineral surfaces is important for bioleaching and the control of acid mine drainage [1,2]
Attachment to minerals, the initial step for bacteria to interact with minerals, is dependent on the preculture conditions such as the ionic strength, pH and energy source
extracellular polymeric substances (EPS) are mainly composed of carbohydrates, proteins, lipids, uronic acids and extracellular DNA
Summary
Understanding bacterial attachment to mineral surfaces is important for bioleaching and the control of acid mine drainage [1,2]. Attachment to minerals, the initial step for bacteria to interact with minerals, is dependent on the preculture conditions such as the ionic strength, pH and energy source. These factors induce bacterial surface hydrophobicity, electrical properties and surface functions [1,3,4], thereby determining how bacteria attach to mineral surfaces. Extracellular polymeric substances (EPS), which cover bacterial cells, are important for mediating attachment on minerals and, leaching the minerals [5,6,7]. The EPS from iron(II) sulfate- or pyrite-grown cells of
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
