Abstract
Acidithiobacillus ferrooxidans is an acidophilic and chemolithotrophic sulfur- and iron-oxidizing bacterium that has been widely used in the bioleaching process for extracting metals. Extracellular polymeric substances (EPS) are essential for bacteria-ore interactions, and the regulation of EPS synthesis could be an important way of influencing the efficiency of the bioleaching process. Therefore, exploring and utilizing the regulatory pathways of EPS synthesis to improve the bacterial bioleaching capability have posed a challenge in the study and application of bioleaching bacteria. Here, several engineering strains were constructed using genetic manipulation methods. And we revealed the regulatory function of the AfeI/R quorum sensing (QS) system in EPS synthesis and biofilm formation of A. ferrooxidans, and the AfeI/R-mediated EPS synthesis could influence bacteria-substrate interactions and the efficiency of bioleaching. Finally, an AfeI/R-mediated bioleaching model was proposed to illustrate the role of QS system in this process. This study provided new insights into and clues for developing highly efficient bioleaching bacteria and modulating the bioleaching process.
Highlights
Bioleaching refers to the direct or indirect actions dissolution of the metal in the ores by microorganisms, and this technology has been rapidly developed and widely used in the production of nonferrous metals over the past few decades [1,2,3].The use of microorganisms in ore processing has some distinct advantages compared to traditional physicochemical methods [4,5,6]
We focused on the genetic manipulation of A. ferrooxidans, and successfully developed the afeI/R
As shown in the electrophoresis gel results (Figure 1B), the DNA fragments amplified from the genome of ∆qs-I were smaller than those amplified from the wide type strain using the primer pairs, P1F/R and P2F/R
Summary
Bioleaching refers to the direct or indirect actions dissolution of the metal in the ores by microorganisms, and this technology has been rapidly developed and widely used in the production of nonferrous metals (gold, copper, uranium, etc.) over the past few decades [1,2,3].The use of microorganisms in ore processing has some distinct advantages compared to traditional physicochemical methods [4,5,6]. Bioleaching refers to the direct or indirect actions dissolution of the metal in the ores by microorganisms, and this technology has been rapidly developed and widely used in the production of nonferrous metals (gold, copper, uranium, etc.) over the past few decades [1,2,3]. On the one hand, bioleaching reduces production costs, because it does not require a large amount of energy during the roasting or smelting process [4,5,6]. On the other hand, bioleaching is significantly advantageous in extracting metals from certain low-grade ores [4,5,6]. The application of bioleaching technology has been extended from biomining to the treatment of metal-containing wastes, such as sewage sludge, mine tailings, and printed circuit boards [7,8,9]. Due to the insufficient understanding of bioleaching bacteria, the conditions of most bioleaching plants are far from optimal, so the study of the physiological metabolism of bioleaching bacteria is necessary [10,11]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
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.
