Sulfur-doped titanium dioxide exhibits a strong visible-light-induced antibacterial effect. The new photocatalyst can effectively kill Micrococcus lylae, a common Gram-positive bacterium. The relationship between sulfur concentration and the bactericidal activity of S-doped TiO2 was investigated. Results from DMPO spin-trapping electron spin resonance measurements confirm the formation of hydroxyl radicals, which is the origin of the considerable bactericidal activity under visible light irradiation.

The challenge in the artificial photosynthesis of fossil resources from CO by utilizing solar energy is to achieve stable photocatalysts with effective CO adsorption capacity and high charge-separation efficiency. A hierarchical direct Z-scheme system consisting of urchin-like hematite and carbon nitride provides an enhanced photocatalytic activity of reduction of CO to CO, yielding a CO evolution rate of 27.2 µmol g h without cocatalyst and sacrifice reagent, which is >2.2 times higher than that produced by g-C N alone (10.3 µmol g h ). The enhanced photocatalytic activity of the Z-scheme hybrid material can be ascribed to its unique characteristics to accelerate the reduction process, including: (i) 3D hierarchical structure of urchin-like hematite and preferable basic sites which promotes the CO adsorption, and (ii) the unique Z-scheme feature efficiently promotes the separation of the electron-hole pairs and enhances the reducibility of electrons in the conduction band of the g-C N . The origin of such an obvious advantage of the hierarchical Z-scheme is not only explained based on the experimental data but also investigated by modeling CO adsorption and CO adsorption on the three different atomic-scale surfaces via density functional theory calculation. The study creates new opportunities for hierarchical hematite and other metal-oxide-based Z-scheme system for solar fuel generation.

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In enteric bacteria the products of two nitrogen regulatory genes, ntrA and ntrC, activate transcription of ginA, the structural gene encoding glutamine synthetase, both in vivo and in vitro. The ntrC product (gpntrC) is a DNA-binding protein, which binds to five sites in the ginA promoter-regulatory region and appears to activate transcription initiation.Using as an assay the stimulation of ginA transcription in a coupled in vitro transcription-translation system, we have partially purified the ntrA gene product (gpntrA). The following evidence is consistent with the view that gpntrA is a or subunit for RNA polymerase! (i) The gpntrA activity copurifies with the 470 holoenzyme (Eo7O) and core (E) forms of RNA polymerase through several steps but can be separated from them by chromatography on heparin agarose. (ii) After further purification by molecular sieve chromatography, the partially purified gpntrA fraction allows transcription ofginA from the same startpoint used in vivo; transcription is dependent on gpntiC and on added E. The gpntrA fraction does not allow transcription from promoters that we have used as controls, including lacUV5. Ea~70 has the reverse specificity.