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A GCxGC-MS system was employed with a non-polar × mid-polar column set for the metabolic non-target analysis of Cobetia marina, the model bacteria for marine biofouling. C. marina was treated with ozone to investigate the intracellular metabolic state change under oxidative stress. A minimal inhibitory concentration test was involved to guarantee that the applied ozone dosages were not lethal for the cells. In this study, non-target analyses were performed to identify the metabolites according to the NIST database. As a result, over 170 signals were detected under normal living conditions including 35 potential metabolites. By the comparison of ozone-treated and non-treated samples, five compounds were selected to describe observed trends of signals in the contour plots. Oleic acid exhibited a slight growth by increasing ozone dosage. In contrast, other metabolites such as the amino acid l-proline showed less abundance after ozone treatment, which was more evident once ozone dosage was raised. Thus, this work could provide a hint for searching for up/downregulating factors in such environmental stress conditions for C. marina.

Nanoporous (np) gold is a promising catalyst material for selective oxidation reactions. Especially the addition of oxide deposits like ceria (CeO2) promises enhanced morphological stability for high temperature applications. Describing such temperature induced morphological changes in porous materials is challenging. Here, X-ray nanoanalysis is particularly promising due to the high penetration depth that allows studying of the bulk properties with high spatial sensitivity. We applied soft X-ray small angle scattering (SAXS) to determine temperature induced structural changes in nanoporous gold catalysts. The results show that CeO2 deposits enhance the temperature stability of the nanoporous gold catalyst. Moreover, we demonstrate the ability of soft X-rays to selectively provide structural information on the stabilizing cerium oxide deposits via resonant, anomalous SAXS (ASAXS) measurements at the cerium M-edge, revealing no growth of the ceria particles.

3-Hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase was investigated in different organic cosolvents by means of kinetic and calorimetric measurements, molecular dynamics simulations, and small-angle X-ray scattering. The combined experimental and theoretical techniques were essential to complement each other's limitations in the investigation of the complex interaction pattern between the enzyme, different solvent types, and concentrations. In this way, the underlying mechanisms for the loss of enzyme activity in different water-miscible solvents could be elucidated. These include direct inhibitory effects onto the active center and structural distortions.