Biomining the Future, UV Induced Mutagenesis on Shewanella Oneidensis to Promote Rare Earth Element Extraction in Coal

SCIENCE

Michael Martinez

Elements that can produce greater battery efficiency in advanced technology and be of use in national defense are in high demand (Jaroni et. al 2019). Major countries like the United States (U.S) and China use rare earth elements (REEs) to advance their technological powers. These REE are lanthanides, elements 57-71 including scandium and yttrium. REEs are difficult to extract with conventional methods and have proven to not be cost efficient to mine. Ten years ago, China realized it was able to control the REE market. China undercut REE prices and outcompeted other countries. China currently mines and controls approximately 90% of the world’s available REE supply. As such, there is a large chance of the U.S not having access to significant REE in the near future. Alaska does show promise in helping boost the REE supply of the U.S and providing economic opportunity to the state. The Bokan Mountain in Alaska has an REE deposit and Ucore Rare Metals Project is acting to begin REE extractions by 2024 (DOE OEERE, 2020). Having an available REE supply in the United States would encourage industries to continue growing nationally including: electric vehicles, national defense, renewable energy and space technology.

REEs are in great demand and are only expected to increase due to the multitude of uses. In a recent study, bacteria Candida bombicola was used to extract REE from coal fly ash and the results showed that 67.7% of ytterbium as well as 64.6% of erbium were extracted (Park & Liang, 2019). An Alaskan study between the University of Alaska Fairbanks and University of Alaska Anchorage showed Shewanella oneidensis MR-1 was able to biomine up to 75.3% for specific neodymium. 98.4% of total REE was also able to be biomined with S. oneidensis MR-1 at around circumneutral pH from mine grade coal which contains more REE (Sachan, 2019). This project seeks to further investigate the biomining capabilities of S. oneidensis MR-1 by producing gain of function mutations to extract highly valued heavy REE from Alaskan coal. Heavy REE are of interest because they are less abundant than light REE and are crucial in developing new technology due to their magnetic properties. For example, holmium is a heavy REE that has the strongest magnetic properties and is able to help create magnetic fields used within hybrid vehicles as well as wind turbines (Department of Natural Resources and Mines Queensland, 2014).

Microbes offer an alternative method to extract REEs that may be more efficient and more environmentally friendly than current technologies. Acid mine drainage is a conventional method of extracting REEs where mine drainage is spread over a large land area and this can cause leakage into the surrounding environment if not properly contained. Heap leaching is another method which uses bacteria, but related problems from heap leaching include: bacteria being released into the surrounding ecosystem, weather affecting bacterial performance outside and water sources for humans becoming contaminated (Reichardt, 2008). Future green mining and space mining cannot be done with conventional methods. Microorganisms may bring industry into a new age of green biomining on Earth and in space. Microbes provide a form of green biotechnology where REEs can be extracted from coal through a redox cycling process at a circumneutral pH. S. oneidensis MR-1 is a microbe that can survive both oxic and anoxic conditions and force the redox cycling of iron within coal. This process weathers the coal from the inside out so more REEs are released into the media.

Profile

Name: Michael Martinez, Undergraduate Student

Institution: University of Alaska Anchorage

Major: Chemistry

Mentor: Brandon Briggs, bbriggs6@alaska.edu

Award: Apprenticeship

Funding Period: 2020 to 2021