Insights into Polyphospahte granules: CryoSTEM validation and arsenate bioremediation potential

Bacteria store polymers of inorganic polyphosphate (PolyP) in granules. Our research aims to unveil the PolyP nano-compartments, in radiation-resistant Deinococcus radiodurans (Dr), which are crucial for its stress response, containing metals such as K, Ca, and Mn, as confirmed by X-ray fluorescence imaging (XRF). Cryo-STEM-EDX analyses validated previous XRF results, revealing high P concentration and other metals like K, Na, and Mg. However, signals for Ca, Mn, and Fe were undetectable. Deinococcus indicus, exhibits radiation resistance and tolerance to high arsenic concentrations. Given the chemical similarities between arsenate and phosphate, we hypothesize that arsenate may be store in the nano-compartments, suggesting potential bioremediation applications. Given the growing interest in CryoEM, our proposal is essential for CryoSTEM-EDX validation, ensuring a comprehensive comparison with XRF. Additionally, it explores the potential of nano-compartments for As bioremediation.