Laboratoire de Sciences de la Terre, Université de Lyon, Ecole Normale Supérieure de Lyon, CNRS, Université Lyon 1, Lyon, France.
Geobiology. 2011 Mar;9(2):196-204. doi: 10.1111/j.1472-4669.2010.00270.x. Epub 2011 Jan 14.
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 mM) 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.
X 射线吸收光谱学是一种成熟的方法，可用于探测各种系统中局部结构和电子原子环境。我们使用 X 射线近边结构（XANES）光谱学实时监测在高压条件下 Shewanella oneidensis MR-1 活体培养物中硒的原位还原。高质量的 XANES 数据表明，Shewanella oneidensis MR-1 将亚硒酸盐 Se(IV)还原为红色元素硒 Se(0)，最高可达 150 MPa，没有任何中间氧化还原态。MR-1 在 0.1 至 60 MPa 之间还原所有提供的亚硒酸盐（5-10 mM）。高于 60 MPa，亚硒酸盐还原产率随压力呈线性下降，活性计算在 155 ± 5 MPa 时停止。对原位测量后回收的培养物的分析表明，活性的降低与生存能力的降低有关。这项研究强调了 XANES 光谱学在实时探测活体样品中广泛金属和类金属元素原位微生物氧化还原转化方面的有前途的潜力，包括在高压下。
