Bio-removal of rare earth elements from hazardous industrial waste of CFL bulbs by the extremophile red alga Galdieria sulphuraria

Anjali Singh; Mária Čížková; Vít Náhlík; Dana Mezricky; Dominik Schild; Marian Rucki; Milada Vítová

doi:10.3389/fmicb.2023.1130848

Bio-removal of rare earth elements from hazardous industrial waste of CFL bulbs by the extremophile red alga Galdieria sulphuraria

Front Microbiol. 2023 Feb 13:14:1130848. doi: 10.3389/fmicb.2023.1130848. eCollection 2023.

Authors

Anjali Singh¹, Mária Čížková¹, Vít Náhlík^{1

2}, Dana Mezricky³, Dominik Schild³, Marian Rucki⁴, Milada Vítová^{1

5}

Affiliations

¹ Laboratory of Cell Cycles of Algae, Centre Algatech, Institute of Microbiology, Czech Academy of Sciences, Třeboň, Czechia.
² Faculty of Fisheries and Protection of Waters, South Bohemian Research Center of Aquaculture and Biodiversity of Hydrocenoses, Institute of Aquaculture and Protection of Waters, University of South Bohemia, České Budějovice, Czechia.
³ Institute of Medical and Pharmaceutical Biotechnology, IMC FH Krems, Krems, Austria.
⁴ Laboratory of Predictive Toxicology, National Institute of Public Health, Prague, Czechia.
⁵ Centre for Phycology, Institute of Botany, Czech Academy of Sciences, Třeboň, Czechia.

Abstract

In recent decades, a shift has been seen in the use of light-emitting diodes over incandescent lights and compact fluorescent lamps (CFL), which eventually led to an increase in wastes of electrical equipment (WEE), especially fluorescent lamps (FLs) and CFL light bulbs. These widely used CFL lights, and their wastes are good sources of rare earth elements (REEs), which are desirable in almost every modern technology. Increased demand for REEs and their irregular supply have exerted pressure on us to seek alternative sources that may fulfill this demand in an eco-friendly manner. Bio-removal of wastes containing REEs, and their recycling may be a solution to this problem and could balance environmental and economic benefits. To address this problem, the current study focuses on the use of the extremophilic red alga, Galdieria sulphuraria, for bioaccumulation/removal of REEs from hazardous industrial wastes of CFL bulbs and the physiological response of a synchronized culture of G. sulphuraria. A CFL acid extract significantly affected growth, photosynthetic pigments, quantum yield, and cell cycle progression of this alga. A synchronous culture was able to efficiently accumulate REEs from a CFL acid extract and efficiency was increased by including two phytohormones, i.e., 6-Benzylaminopurine (BAP - Cytokinin family) and 1-Naphthaleneacetic acid (NAA - Auxin family).

Keywords: Galdieria sulphuraria; Rhodophyta; bio-removal; compact fluorescent lamp; extremophile; industrial wastes; plant hormones.