This chapter discusses the ecological and physiological impacts of lanthanides on algae as primary producers in aquatic environments. Although lanthanides are nonessential elements for living organisms, their bioaccumulation is a common phenomenon. Here, we critically review the ecological effects of increasing levels of lanthanides directly reaching water systems through mining, application of fertilizers, and the production of advanced technologies. We describe interactions between lanthanides and algae, with a particular focus on various applications including fertilizers, tracers, bioindicators, bioremediation, and recycling. We examine the stimulatory effects of low levels of lanthanides versus their toxicity at higher levels and discuss mechanisms by which they may affect the algal cell. This chapter highlights the importance of a better understanding of the biological roles of lanthanides.
Part of the book: Lanthanides
The genus Galdieria refers to red algae and includes microscopic inhabitants of highly acidic (pH 1–2), often volcanic habitats. They are thermophilic or thermo-tolerant organisms, some of them surviving temperatures up to 56°C. As other extremophilic microorganisms, they exhibit unique features derived from their modified metabolisms. In this chapter, we will review the special abilities of Galdieria species such as metabolic flexibility to grow photoautotrophically, heterotrophically or mixotrophically, ability to utilize a whole range of unusual carbon sources, capability of surviving extreme environments or their extremely high resistance to metals. We will discuss the potential of Galdieria for applications in biotechnology, for example, phycocyanin production, nutrient removal from urban wastewaters, bio-mining, treatment of acidic mine drainage, selective metal precipitation, bioremediation of acidic metal-contaminated areas or recovery of critical and scarce metals from secondary sources.
Part of the book: Microalgae - From Physiology to Application