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Monitoring microbial redox transformations of metal and metalloid elements under high pressure using in situ X‐ray absorption spectroscopy
Author(s) -
PICARD A.,
DANIEL I.,
TESTEMALE D.,
KIEFFER I.,
BLEUET P.,
CARDON H.,
OGER P. M.
Publication year - 2011
Publication title -
geobiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.859
H-Index - 72
eISSN - 1472-4669
pISSN - 1472-4677
DOI - 10.1111/j.1472-4669.2010.00270.x
Subject(s) - shewanella oneidensis , xanes , selenium , metalloid , redox , hydrostatic pressure , chemistry , shewanella , absorption (acoustics) , absorption spectroscopy , x ray absorption spectroscopy , spectroscopy , in situ , metal , analytical chemistry (journal) , materials science , inorganic chemistry , environmental chemistry , bacteria , geology , paleontology , physics , organic chemistry , quantum mechanics , composite material , thermodynamics
X‐ray absorption spectroscopy is a well‐established method for probing local structural and electronic atomic environments in a variety of systems. We used X‐ray absorption near‐edge structure (XANES) spectroscopy for monitoring in real‐time conditions selenium reduction in situ in live cultures of Shewanella oneidensis MR‐1 under high hydrostatic pressure. High‐quality XANES data show that Shewanella oneidensis MR‐1 reduces selenite Se(IV) to red elemental selenium Se(0) up to 150 MPa without any intermediate redox state. MR‐1 reduces all selenite provided (5–10 m m ) between 0.1 and 60 MPa. Above 60 MPa the selenite reduction yield decreases linearly with pressure and the activity is calculated to stop at 155 ± 5 MPa. The analysis of cultures recovered after in situ measurements showed that the decrease in activity is linked to a decrease in viability. This study emphasizes the promising potential of XANES spectroscopy for real‐time probing in situ microbial redox transformations of a broad range of metal and metalloid elements in live samples, including under high hydrostatic pressure.