Contribution of the Kodama and 4S pathways to the dibenzothiophene biodegradation in different coastal wetlands under different C/N ratios.

Dibenzothiophene (DBT) degradation mechanisms and the transformation of pathways during the incubation of three types of coastal sediments with C/N ratios ranging from 1 to 9 were investigated. The DBT degradation efficiencies were clearly improved with increasing C/N ratio in reed wetland sediments, tidal wetlands sediments and estuary wetland sediments. The quantitative response relationships between DBT degradation rates and related functional genes demonstrate that the Kodama pathway-related gene groups were dominant factors at low C/N ratios, while the 4S-related gene groups mainly determined the degradation rate when the C/N ratio was up to 5. Network analysis also shows that the pathway shifts from the Kodama pathway to the 4S pathway occurred through changes in the connections between functional genomes and rates. Furthermore, there were competition and collaboration between the Kodama and 4S pathways. The 4S pathway-related bacteria were more active in estuary wetland sediments compared with reed wetland sediments and tidal wetland sediments. The higher degradation efficiency in estuary wetland sediments may indicate the greater participation of the 4S pathway in the DBT biodegradation reaction. And the effects of ring cleavage of Kodama pathway caused more complete metabolizing of DBT.

A chemically induced, room temperature, single source precursor to CuS (covellite) nanomaterials: synthesis and reactivity of [Cu(S2CNHBz)]n.

Addition of two equivalents of NaS2CNHBz to CuSO4 affords the yellow diamagnetic coordination polymer [Cu(S2CNHBz)]n (1), resulting from intramolecular electron-transfer and concomitant formation of the thiourea, (BzNH)2CS. 1 reacts with PPh3 and 1,1'-bis(diphenylphosphino)ferrocene (dppf) in CH2Cl2 to give monomeric [Cu(κ2-S2CNHBz)(PPh3)2] (2) and [Cu(κ2-S2CNHBz)(κ2-dppf)] (3), respectively, both of which have been crystallographically characterised. While 1 is thermally stable in dimethylsulfoxide (DMSO) up to ca. 70 °C, addition of nBuNH2 to 1 leads to its rapid decomposition to afford CuS (covellite) nanomaterials; indeed in neat nBuNH2, covellite formation is rapid at room temperature. Thus, 1 serves as an effective low-temperature base-induced single source precursor to covellite nanomaterials.