Commonwealth Scientific and Industrial Research Organisation (CSIRO), Floreat WA 6014, Australia.
Published: February 2018
AI Article Synopsis
Article Abstract
Biomining with acidophilic microorganisms has been used at commercial scale for the extraction of metals from various sulfide ores. With metal demand and energy prices on the rise and the concurrent decline in quality and availability of mineral resources, there is an increasing interest in applying biomining technology, in particular for leaching metals from low grade minerals and wastes. However, bioprocessing is often hampered by the presence of inhibitory compounds that originate from complex ores. Synthetic biology could provide tools to improve the tolerance of biomining microbes to various stress factors that are present in biomining environments, which would ultimately increase bioleaching efficiency. This paper reviews the state-of-the-art tools to genetically modify acidophilic biomining microorganisms and the limitations of these tools. The first part of this review discusses resilience pathways that can be engineered in acidophiles to enhance their robustness and tolerance in harsh environments that prevail in bioleaching. The second part of the paper reviews the efforts that have been carried out towards engineering robust microorganisms and developing metabolic modelling tools. Novel synthetic biology tools have the potential to transform the biomining industry and facilitate the extraction of value from ores and wastes that cannot be processed with existing biomining microorganisms.
Aim: This project evaluated a biologically mediated strategy to solubilize several rare earth elements and critical raw materials, including scandium, from bauxite residue. This work seeks to expand on previous research on contact leaching with bauxite.
Methods And Results: In this study, Gluconobacter oxydans was shown to secrete mixed organic acids, including gluconic acid, which was superior to pure gluconic acid in the dissolution of bauxite residue, even at low molarities.
Harsh climatic conditions and lack of topsoil in China's cold resistance zone pose challenges for ecological restoration of open-pit mine dumps, leading researchers to develop synthetic soil using mineral black clay.
The introduction of an ecological restoration bacteria (ERB) consortium significantly altered the native bacterial community structure, increasing diversity by combating the dominance of inhibitory bacteria.
This microbial alteration improved soil composition and plant diversity, promoting the growth of Salsola collina and Medicago sativa, enhancing nutrient cycling, and fostering beneficial plant-microbe interactions for successful ecological remediation.
* E-waste recycling is crucial due to the environmental and health risks posed by heavy metals and pollutants, and heterotrophic microbes offer potential solutions for eco-friendly metal recovery through their natural metal-binding biomolecules.
* The review discusses current challenges in using organic acid and biocyanide leaching for metal recovery, as well as innovative methods and emerging technologies that can improve the efficiency and impact of these biological approaches.
Acidithiobacillus ferrooxidans is an acidophilic chemolithoautotroph that plays an important role in biogeochemical iron and sulfur cycling and is a member of the consortia used in industrial hydrometallurgical processing of copper. Metal sulfide bioleaching is catalyzed by the regeneration of ferric iron; however, bioleaching of chalcopyrite, the dominant unmined form of copper on Earth, is inhibited by surface passivation. Here, we report the implementation of CRISPR interference (CRISPRi) using the catalytically inactive Cas12a (dCas12a) in A.
