Browsing by Author "Kohl, Jana"

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Open Access
Intracellular bioaccumulation of the rare earth element Gadolinium in ciliate cells resulting in biogenic particle formation and excretion
(2023) Kohl, Jana; Schweikert, Michael; Klaas, Norbert; Lemloh, Marie-Louise
Ciliates are abundant unicellular organisms capable of resisting high concentrations of metal ions in the environment caused by various anthropogenic activities. Understanding the cellular pathways involved in resistance to and detoxification of elements is required to predict the impact of ciliates on environmental element cycles. Here, we investigated the so far unknown process of tolerance, cellular uptake and bioaccumulation of the emerging rare earth element gadolinium (Gd) in the common ciliate Tetrahymena pyriformis. Gd treatment results in the intracellular formation and excretion of biogenic Gd-containing particles. This cellular process effectively removes dissolved Gd from the organic growth medium by 53.37% within 72 h. Based on light and electron microscopic observations, we postulate a detoxification pathway: Cells take up toxic Gd 3+ ions from the medium by endocytosis, process them into stable Gd-containing particles within food vacuoles, and exocytose them. Stable biogenic particles can be isolated, which are relatively homogeneous and have a diameter of about 3 µm. They consist of the elements Gd, C, O, P, Na, Mg, K, and Ca. These findings broaden the view of metal ion accumulation by protists and are of relevance to understand environmental elemental cycles and may inspire approaches for metal recovery or bioremediation.
Open Access
Unicellular organisms with versatile solutions at the micro‐scale : functional materials and principles in ciliates
(2023) Dörr, Lennart; Kohl, Jana; Schweikert, Michael; Lemloh, Marie‐Louise
Nature's diversity offers an abundance of promising solutions for novel bioinspired functional materials and systems. In particular, single‐celled organisms exhibit solutions and material properties that are realized at the nano‐ and micro‐scales. Ciliates are ubiquitous unicellular eukaryotes that are well‐adapted to a wide range of environmental conditions. They have developed a large variety of interesting and highly specialized characteristics with unique properties and design. In this review, the background of selected ciliate characteristics is highlighted with respect to material properties and structure‐function relationships. Hierarchically complex mineralized structures, highly efficient sensors for movement and protection, shape‐memory structures, as well as survival and detoxification strategies are to be emphasized. Proposed future bioinspired applications of these properties of ciliates expand the possibilities to more sustainable materials and development processes.