Metal Sulfide Biomineralization by Magnetotactic Bacteria

Download or read book Metal Sulfide Biomineralization by Magnetotactic Bacteria written by Yeseul Park and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Biomineralization of metal sulfides has been broadly observed in microbial cultures and in nature. However, only a few cases have been reported as biologically-controlled processes, such as greigite produced by magnetotactic bacteria. I discovered a new type of intracellular metal sulfide biomineralization, while studying the impact of copper on greigite biomineralization by the magnetotactic bacterium Desulfamplus magnetovallimortis strain BW-1.The newly discovered metal sulfide biominerals are nanoscopic particles and have an interesting crystal structure and organization. These spherical or ellipsoidal particles are composed of 1-2 nm-sized sub-grains of hexagonal copper sulfide that remains in a metastable state. The particles are located in the periplasmic space, surrounded by an organic substance. Based on these observations, it was concluded that the biomineral produced and conserved is a result of biological control. Proteomics studies with cellular and particulate samples identified several proteins associated with the process. The initial result showed that two periplasmic proteins, a heavy metal resistant protein, and a DegP-like protease, are likely working together to react to the envelope stress caused by copper. Such intracellular biomineralization is organism-specific and only initiated by the increase of copper ions, but not by other metal ions like nickel, zinc, or cobalt. Overall, my work reveals unknown features of metal sulfide biomineralization, specifically within magnetotactic bacteria.