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For steady electroconversion to value-added chemical products with high efficiency, electrocatalyst reconstruction during electrochemical reactions is a critical issue in catalyst design strategies. Here, we report a reconstruction-immunized catalyst system in which Cu nanoparticles are protected by a quasi-graphitic C shell. This C shell epitaxially grew on Cu with quasi-graphitic bonding via a gas–solid reaction governed by the CO (g) - CO2 (g) - C (s) equilibrium. The quasi-graphitic C shell-coated Cu was stable during the CO2 reduction reaction and provided a platform for rational material design. C2+ product selectivity could be additionally improved by doping p-block elements. These elements modulated the electronic structure of the Cu surface and its binding properties, which can affect the intermediate binding and CO dimerization barrier. B-modified Cu attained a 68.1% Faradaic efficiency for C2H4 at −0.55 V (vs RHE) and a C2H4 cathodic power conversion efficiency of 44.0%. In the case of N-modified Cu, an improved C2+ selectivity of 82.3% at a partial current density of 329.2 mA/cm2 was acquired. Quasi-graphitic C shells, which enable surface stabilization and inner element doping, can realize stable CO2-to-C2H4 conversion over 180 h and allow practical application of electrocatalysts for renewable energy conversion.

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Five novel species of the genus Nocardiopsis isolated from hypersaline soils and emended description of Nocardiopsis salina Li et al. 2004

Staphylococcus aureus is a versatile human pathogen that produces diverse virulence factors, and its biofilm cells are difficult to eradicate due to their inherent ability to tolerate antibiotics. The anti-biofilm activities of the spent media of 252 diverse endophytic microorganisms were investigated using three S. aureus strains. An attempt was made to identify anti-biofilm compounds in active spent media and to assess their anti-hemolytic activities and hydrophobicities in order to investigate action mechanisms. Unlike other antibiotics, actinomycin D (0.5 μg ml(-1)) from Streptomyces parvulus significantly inhibited biofilm formation by all three S. aureus strains. Actinomycin D inhibited slime production in S. aureus and it inhibited hemolysis by S. aureus and caused S. aureus cells to become less hydrophobic, thus supporting its anti-biofilm effect. In addition, surface coatings containing actinomycin D prevented S. aureus biofilm formation on glass surfaces. Given these results, FDA-approved actinomycin D warrants further attention as a potential antivirulence agent against S. aureus infections.

A novel halophilic actinomycete, designated strain YIM 93223 T , was isolated from a salt lake in Xinjiang Province, north-west China, and was subjected to a polyphasic taxonomic study. The isolate grew at 25-45 6C, at pH 6-8 and in the presence of 1-15 % (w/v) NaCl; no growth was observed in the absence of NaCl. Strain YIM 93223T contained meso-diaminopimelic acid, glutamic acid and alanine as cell-wall amino acids, and glucose and galactose as major whole-cell-wall sugars. Major fatty acids were iso-C 16 : 0 , C 16 : 0 and

Nesterenkonia sandarakina sp. nov. and Nesterenkonia lutea sp. nov., novel actinobacteria, and emended description of the genus Nesterenkonia

A moderately halophilic actinomycete strain, designated YIM 90010 T , was isolated from a soil sample collected from a hypersaline habitat in Xinjiang Province, China, and then investigated using a polyphasic taxonomic approach. The strain produced abundant aerial mycelia and fragmented substrate mycelia on most media tested; the optimum NaCl concentration for growth was 10 % (w/v) and the optimum growth temperature and pH were 28 6C and 7?2, respectively. Chemotaxonomically and phylogenetically, the strain was related to members of the genus Nocardiopsis. The isolate contained chemotaxonomic markers that were diagnostic for the genus Nocardiopsis, i.e. meso-diaminopimelic acid, no diagnostic sugars, and MK-10(H 6 ), ) and MK-12 as the predominant menaquinones. The major fatty acids were iso-and anteiso-branched acids combined with tuberculostearic acid (Me C 18 : 0 ), straight-chain saturated fatty acids and unsaturated fatty acids. The G+C content was 73?1 mol%. Phylogenetic analysis confirmed that strain YIM 90010T was a member of the genus Nocardiopsis and most closely related to Nocardiopsis kunsanensis (97?6 % similarity) and Nocardiopsis xinjiangensis (98?1 % similarity). It can be differentiated from these species by using phenotypic characteristics, phylogenetic analysis and DNA-DNA hybridization results. On the basis of the polyphasic evidence, a novel species, Nocardiopsis salina sp. nov., is proposed. The type strain of the species is YIM 90010 T (=KCTC 19003 T =CCTCC AA 204009 T ).The genus Nocardiopsis was first described by Meyer (1976) and currently comprises 18 species with validly published names (Meyer, 1976;Grund & Kroppenstedt, 1990;Yassin et al., 1993Yassin et al., , 1997Al-Tai & Ruan, 1994; Evtushenko et al., 2000;Chun et al., 2000; Peltola et al., 2001;Al-Zarban et al., 2002; Kämpfer et al., 2002; Schippers et al., 2002;M. G. Li et al., 2003; Hozzein et al., 2004;Sabry et al., 2004). During our taxonomic study on extremophilic actinomycetes, we used phenotypic and genotypic approaches to facilitate the characterization of one moderately halophilic actinomycete, strain YIM 90010Strain YIM 90010 T was isolated from a saline soil sample by using modified International Streptomyces Project (ISP) 5 medium supplemented with 20 % (w/v) NaCl. The soil sample was collected from the same source as described previously (Cui et al., 2001;M. G. Li et al., 2003; W. J. Li et al., 2003a, b, c). The strain was maintained on ISP 2 and ISP 5 slants containing 10 % (w/v) NaCl at 4 u C and as 20 % (w/v) glycerol suspensions at 220 uC. Biomass for chemical and molecular studies was obtained by cultivation in shake flasks (about 150 r.p.m.) using modified ISP 5 medium [10 % (w/v) NaCl, pH 7?0] broth at 28 u C for 1 week.The morphological characteristics of strain YIM 90010 T were observed by using light microscopy (model BH 2; Olympus) and scanning electron microscopy with a JEOL model JSM5600LV after 14 days growth on ISP 5 medium containing 10 % (w/v) NaCl. Cultural characteristics were determined afte...