Affiliation:
1. Galdieria, Co., Ltd., Yokohama 2300046, Kanagawa, Japan
Abstract
The red microalga Galdieria sp. is an extremophile that inhabits acidic hot sulphur springs and grows heterotrophically to a high cell density. These characteristics make Galdieria suitable for commercial applications as stable mass production is the key to success in the algae business. Galdieria has great potential as a precious metal adsorbent to provide a sustainable, efficient and environmentally benign method for urban mining and artisanal small-scale gold mining. The efficiency and selectivity in capturing precious metals, gold and palladium from metal solutions by a Galdieria-derived adsorbent was assessed relative to commercially used adsorbents, ion exchange resin and activated charcoal. As it is only the surface of Galdieria cells that affect metal adsorption, the cell content was analysed to determine the manner of utilisation of those metabolites. Galdieria was shown to be protein-rich and contain beneficial metabolites, the levels of which could shift depending on the growth conditions. Separating the cell content from the adsorbent could improve the adsorption efficiency and reduce CO2 emissions during the metal collection process. The commercial applications of Galdieria appear promising: growth is quick and dense; the precious metal adsorption capacity is highly efficient and selective in acidic conditions, especially at low metal concentrations; and the cell content is nutrient-rich.
Subject
Inorganic Chemistry,Organic Chemistry,Physical and Theoretical Chemistry,Computer Science Applications,Spectroscopy,Molecular Biology,General Medicine,Catalysis
Reference43 articles.
1. Biosorption: Critical Review of Scientific Rationale, Environmental Importance and Significance for Pollution Treatment;Gadd;J. Chem. Technol. Biotechnol.,2009
2. Removal of Microplastics from the Environment. A Review;Padervand;Environ. Chem. Lett.,2020
3. A Novel Role for Methyl cysteinate, a Cysteine Derivative, in Cesium Accumulation in Arabidopsis thaliana;Adams;Sci. Rep.,2017
4. Hewitt, A., Keel, T., Tauber, M., and Le-Fiedler, T. (2015). The Ups and Downs of Gold Recycling, World Gold Council.
5. Interaction of Saccharomyces cerevisiae with Gold: Toxicity and Accumulation;Karamushka;Biometals,1999