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Microbial synthesis of unique nanoscale minerals - challenges and prospects

Maliszewska Irena, Kocek Daria, Wanarska Ewelina

Physicochemical Problems of Mineral Processing

2020

Vol. 56, iss. 6

244--256

In this review, we highlight new insights and place the molecular mechanisms of the biogenesis of nanomaterials such as silicified frustules, coccoliths, magnetosomes and bacterial nanowires in the context of the complex biology of a microbial cell. The silicified frustules are formed by diatoms, which are a widespread group of organisms found in the oceans, fresh water, soil and wet surfaces. They are especially important in the oceans, where it is estimated that they contribute to 45% of total primary ocean production. Coccolith is a collective term that designates all of the biomineralized, calcified scales produced by extant and extinct haptophytes (single-celled algae). The orientation of magnetotactic bacteria is based on the presence of unique organelles, magnetosomes, which are intracellular, membrane-enclosed, nanometre-sized crystals of magnetic iron minerals. The discovery of bacterial conductive structures, called nanowires, has fascinated scientists for almost a decade. Nanowires enable bacteria to transfer electrons over micrometer distances to extracellular electron acceptors such as insoluble metal oxides or electrodes. The possible applications of these extremely interesting nanomaterials in different areas of life is also considered.

Derived marine microfossils in loesses of the last glaciation and their significance in the reconstruction of loess-forming processes in central-eastern Europe

Paruch-Kulczycka J., Chlebowski R., Lindner L.

Geological Quarterly

2003

Vol. 47, No 2

119-132

Documented examples of type sections with Pleistocene deposits in southern Poland (Tłumaczów, Branice, Wożuczyn, Tyszowce, Hrubieszów) and southwestern Ukraine (Bojanice, Horokhov, Zhorniv) indicate that loesses of the last glaciation (Vistulian, Valdayan) contain derived marine microfossils of Cretaceous age. The microfossil assemblages studied are richly represented by foraminifers, which are mostly well-preserved, and derived mainly Cretaceous, forms. Suitable Late Cretaceous exposures are nearby, around data shows that these rocks and their debris, and the overlying Pleistocene tills and sands, which are older than the loesses, represent one of the main sources of the loess silt. This fact and the heavy mineral content are evidence of the participation of local material in loess-forming processes in central-eastern Europe. The spatial distribution of the sections studied in relation to the determined sources of loess material indicate that the accumulation of the loesses took place mainly in the presence of western and/or northwestern winds in the lower parts of the atmosphere.