# Dysprosium Absorption of Aluminum Tolerant- and Absorbing-Yeast
## 1 Introduction  
Rare metals, including lithium, beryllium, titan, vanadium, chromium, manganese, cobalt, nickel, gallium, germanium, rubidium, strontium, zirconium, niobium, molybdenum, palladium, indium, antimony, tellurium, cesium, barium, hafnium, tantalum, tungsten, thenium, plating, thallium, bismuth, and rare earth elements (REEs) composed of scandium, yttrium and 15 lanthanide elements, are globally scarce and are difficult to replace with other metals in many cases [1]. In particular, REEs are due to the useful features they possess, rare metals are also important for high-tech industries, such as the automobile industry, digital consumer electronics, and information-related devices because they exhibit magnetism, fluorescence, and superconductivity due to their characteristic electron orbitals [2, 3]. As powerful magnetic and superconductive materials are essential for the development of advanced industries that require high energy efficiency, REEs are indispensable ingredients in the manufacture of these products. For these reasons, rare metals, including REEs, are called the vitamins of industry, and the demand for rare metals is increasing due to the ongoing development of these high-tech industries [1]. Recently, the international prices of rare metals have markedly increased because they are required by many members of the high-tech industry, but their supply system is weak. A stable supply system for rare metals is crucial for the development of global science and technology industries. Moreover, large amounts of rare metals are accumulated in high-tech products, and they can be regarded as resources. Therefore, the efficient recovery of rare metals from nature, wastewater, and discarded high-tech products is veryimportant in terms of resource recovery, environmental cleanup, and also sustainable development goals (SDGs). Recently, the biosorption of REEs from REE-containing materials has become a booming process due to its high efficiency, cost effectiveness, versatility, and non-involvement of hazardous chemicals compared to physical or chemical processes, such as co-precipitation, solvent extraction, solid-phase extraction, and ion exchange, which include different organic-inorganic pollutants, toxic metals, and metalloids [4, 5]. Biosorption uses biological methods, such as the metal-binding capacities of different biological materials present in living and non-living biomass, e.g., plant materials, industrial, and agricultural waste, as well as microorganisms such as algae, fungi, bacteria, and yeasts, and recent literature reports have focused on biosorption for the removal of rare earth metals present in bacterial culture [6], the batch culture of brown algae [7] and the biomass of plants [8]. However, the more promising works seem to explore the removal and recovery of REEs from very dilute solutions by biosorption.  
Lanthanides are highly limited resources, and there is a need to establish highly technological apparatus for their removal [9]. Easy and ecological recovery systems for lanthanides would be incredibly useful for the building of smart cities. One particular REE, dysprosium (Dy), is experiencing a rise in demand due to its heat-resistant and powerful magnetic properties. In this study, we attempt to isolate yeast strains that can absorb Dy in order to establish a new recovery system for Dy using the bioresources of liquid waste with low Dy concentrations, such as mine drainage, ore waste, and industrial waste solutions. In this paper, we describe the screening of Dy-absorbing yeast strains and the characteristics for Dy absorption in the selected aluminum (Al)-tolerant and -absorbing strains, which have been previously isolated [10].