Probiotic extraction of rare earth metals for tech.

Introduction:

Rare earth metals (REE) have been long used in the tech industry for the manufacturing of electronics and energy technologies such as turbine generators, battery anodes, electric motors, etc. These applications put a great strain on the global REE supply chain. As the global demand for sustainable energy grows, finding a reliable and sustainable source of REEs becomes increasingly important. Current refining methods generate a great amount of toxic waste, are unsustainable, and are cost-inefficient. This has resulted in an increased interest in biological methods (Bioleaching) being used for the extraction of REEs in addition to the conventional methods and possibly replacing them.

This new study aims to meet the surging demand for rare earth metals by developing a whole-genome knockout collection of Gluconobacter oxydans, a highly promising bacteria for REE bioleaching, such that it is economic, efficient, and clean enough to meet the environmental standards. The paper’s senior author Buz Barstow remarked "We're trying to come up with an environmentally friendly, low-temperature, low-pressure method for getting rare earth elements out of a rock,"

G. oxydans is known for producing a rock-dissolving acid called biolixiviant, which the bacteria uses to extract phosphates from rare earth elements. The researchers have begun to manipulate the genes of G. oxydans to increase the efficiency with which the elements are extracted.

To do so, the researchers used a technology called Knockout Sudoku, which Barstow helped develop, to disable the 2,733 genes in G. oxydans' genome one by one. The team curated mutants, each with a specific gene knocked out, to determine which genes play roles in extracting elements from rock.

The study has helped prove the potential of G.oxydans in improving the bioleaching game, moreover, the creation of the whole-genome knockout collection can be used for further studies and the development of industrially relevant applications of similar acetic acid bacteria.

Reference:

Generation of a Gluconobacter oxydans knockout collection for improved extraction of rare earth elements, Nature Communications (2021). DOI : 10.1038/s41467-021-27047-4

by Bishakha choudhury