TOF-SESANS probing of variations in size polydispersity of bacteria along Hg and SiO2NPs simultaneous biosorption: a follow-up of proposal 2024196

High Hg levels in Amazonian aquatic media indicate heavy metal (HM) pollution and stimulate this biosorption research. Bacterial biosorption is first and strongly controlled by morphological parameters such as the (S⁄V) ratio. Via TOF-SANS we monitored the morphological changes of Klebsiella pneumoniae (KP) driven by Hg+SiO2NPs inputs over time, from the bacterial wall up to their minimal radius (~150 nm). To access larger sizes than experiment 2024196 (KP length ~ 4 um), we propose time-resolved a TOF-SESANS monitoring of structural changes in KP driven by Hg+SiO2NPs inputs over time (8 and 16 ppm Hg). We hypothesise that KP can initially encapsulate Hg increasing their S/V ratio and enhancing their absorption capacity. SESANS is critical as it provides access to measure KP’s size time-variations of length, diameter, and S/V ratio. Samples will contain Hg-resistant non-virulent KP strains, and SiO2NPs, inside 100 % D2O Hg-rich Na-phosphate buffers, totalling 4 time-resolved TOF-SESANS measurements (Mix samples). Other 6 measurements on starting components at 100% D2O will quantify each component's effects on Mix samples. An alternated collection of data over 3 h/sample will replicate the same time-framework of TOF-SANS experiment. BioCOSHH RA got approved for KP strains of experiment 2024196. The importance of this proposal resides in understanding bacterial structure variations in response to chemical changes over time, aiming for future applications in bioremediation.