Ceria-Catalyzed Hydrolytic Cleavage of Sulfonamides.

Nanoceria is a promising nanomaterial for the catalytic hydrolysis of a wide variety of substances. In this study, it was experimentally demonstrated for the first time that CeO2 nanostructures show extraordinary reactivity toward sulfonamide drugs (sulfadimethoxine, sulfamerazine, and sulfapyridine) in aqueous solution without any illumination, activation, or pH adjustment. Hydrolytic cleavage of various bonds, including S-N, C-N, and C-S, was proposed as the main reaction mechanism and was indicated by the formation of various reaction products, namely, sulfanilic acid, sulfanilamide, and aniline, which were identified by HPLC-DAD, LC-MS/MS, and NMR spectroscopy. The kinetics and efficiency of the ceria-catalyzed hydrolytic cleavage were dependent on the structure of the sulfonamide molecule and physicochemical properties of Nanoceria prepared by three different precipitation methods. However, in general, all three ceria samples were able to cleave SA drugs tested, proving the robust and unique surface reactivity toward these compounds inherent to cerium dioxide. The demonstrated reactivity of CeO2 to molecules containing sulfonamide or even sulfonyl (and similar) functional groups may be significant for both heterogeneous catalysis and environmentally important degradation reactions.

Miscanthus x giganteus stress tolerance and phytoremediation capacities in highly diesel contaminated soils.

Second generation biofuel crop Miscanthus x giganteus (Mxg) was studied as a candidate for petroleum hydrocarbons (PHs) contaminated soil phytomanagement. The soil was polluted by diesel in wide concentration gradient up to 50 g⋅kg-1 in an ex-situ pot experiment. The contaminated soil/plant interactions were investigated using plant biometric and physiological parameters, soil physico-chemical and microbial community's characteristics. The plant parameters and chlorophyll fluorescence indicators showed an inhibitory effect of diesel contamination; however much lower than expected from previously published results. Moreover, lower PHs concentrations (5 and 10 g⋅kg-1) resulted in positive reinforcement of electron transport as a result of hormesis effect. The soil pH did not change significantly during the vegetation season. The decrease of total organic carbon was significantly lower in planted pots. Soil respiration and dehydrogenases activity increased with the increasing contamination indicating ongoing PHs biodegradation. In addition, microbial biomass estimated by phospholipid fatty acids increased only at higher PHs concentrations. Higher dehydrogenases values were obtained in planted pots compared to unplanted. PHs degradation followed the first-order kinetics and for the middle range of contamination (10-40 g⋅kg-1) significantly lower PHs half-lives were determined in planted than unplanted soil pointing on phytoremediation. Diesel degradation was in range 35-70 % according to pot variant. Results confirmed the potential of Mxg for diesel contaminated soils phytomanagement mainly in PHs concentrations up to 20 g⋅kg-1 where phytoremediation was proved, and biomass yield was reduced only by 29 %.

Constructed wetlands for the treatment of household organic micropollutants with contrasting degradation behaviour: Partially-saturated systems as a performance all-rounder.

The degradability of specific organic micropollutants in constructed wetlands (CWs) may differ depending on the prevalence of oxic or anoxic conditions. These conditions are governed, among other factors, by the water saturation level in the system. This study investigated the removal of three environmentally-relevant organic micropollutants: bisphenol-group plasticizer bisphenol S (BPS), household-use insecticide fipronil (FPN) and non-steroidal anti-inflammatory drug ketoprofen (KTP) in the model CWs set up in an outdoor column system. BPS and KTP, in contrast to FPN, exhibit higher biodegradability potential under oxic conditions. The experimental CWs were operated under various saturation conditions: unsaturated, partially saturated and saturated, and mimicked the conditions occurring in unsaturated, partially-saturated intermittent vertical-flow CWs and in horizontal-flow CWs, respectively. The CWs were fed with synthetic household wastewater with the concentration of the micropollutants at the level of 30-45 µg/L. BPS and KTP exhibited contrasting behaviour against FPN in the CWs in the present experiment. Namely, BPS and KTP were almost completely removed in the unsaturated CWs without a considerable effect of plants, but their removal in saturated CWs was only moderate (approx. 50%). The plants had only a pronounced effect on the removal of BPS in saturated systems, in which they enhanced the removal by 46%. The removal of FPN (approx. 90%) was the highest in the saturated and partially-saturated CWs, with moderate removal (66.7%) in unsaturated systems. Noteworthy, partially-saturated CWs provided high or very high removal of all three studied substances despite their contrasting degradability under saturated and unsaturated conditions. Namely, their removal efficiencies in planted CWs were 95.9%, 94.5% and 81.6%, for BPS, KTP and FPN, respectively. The removal of the micropollutants in partially-saturated CWs was comparable or only slightly lower than in the best treatment option making it the performance all-rounder for the compounds with contrasting biodegradability properties.

Mucus-derived exosome-like vesicles from the Spanish slug (Arion vulgaris): taking advantage of invasive pest species in biotechnology.

The slug Arion vulgaris has attracted major attention as one of the worst invasive herbivore pests in Europe and is renowned for the stiff mucus it secretes for locomotion. In this study we focused on the isolation and characterisation of extracellular vesicles, specifically exosomes and exosome-like vesicles, from Arion secretions. We developed a method for slug mucus collection and subsequent vesicle isolation by ultracentrifugation. The isolated vesicles with an average diameter of ~ 100 nm carry abundant proteins and short RNAs, as well as adhesion molecules similar to mammalian galectins. We demonstrated that the slug extracellular vesicles are internalised by plant cells and human cancer cells in in vitro assays and are loadable by bioactive compounds, which makes them an interesting tool for utilisation in biotechnology.