Abstract Aims We sought to characterize the antibiotic susceptibility of strains of Stenotrophomonas maltophilia isolated from clinical samples, and the role of Stenotrophomonas maltophilia biofilm in antibiotic resistance. Methods Fifty-one clinical Stenotrophomonas maltophilia isolates were obtained from patients with nosocomial infection in the surgical wards and ICUs of six general hospitals in Tianjin, China. In vitro models of Stenotrophomonas maltophilia biofilms were established and confirmed by scanning electron microscopy and fluorescence microscopy with silver staining. The minimal inhibitory concentrations and biofilm inhibitory concentrations of commonly used antibiotics were determined. Results 47 of 51 strains were resistant to three or more antibiotics. 42 of 51 strains formed Stenotrophomonas maltophilia biofilms in vitro. Stenotrophomonas maltophilia biofilm formation greatly reduced sensitivity to most tested antibiotics, but not to levofloxacin. However, in the presence of erythromycin scanning electron microscopy revealed that levofloxacin inhibited Stenotrophomonas maltophilia biofilm formation. Factorial ANOVA revealed that erythromycin enhanced susceptibility to levofloxacin, cefoperazone/sulbactam, and piperacillin (p < 0.05), and an ΔE model revealed that levofloxacin and erythromycin acted synergistically in biofilms, suggesting specific use of combined macrolide therapy may represent an effective treatment for Stenotrophomonas maltophilia infection. Conclusions Antibiotics could act synergistically to combat the protection conferred to clinical isolates of Stenotrophomonas maltophilia by biofilms. Macrolide antibiotics may be effective where used in combination.

Sugarcane smut disease caused by the fungus Sporisorium scitamineum is one of the important fungal diseases affecting sugarcane yield and sucrose content around the world. Cultivar resistance is the most appropriate control method for this disease. In this study, 37 BC1 lines chosen from the crossing YC96-40 (F1 of Erianthus arundinaceus) × CP84-1198 (commercial sugarcane cultivar) and 42 BC2 lines chosen from the crossing YCE01-116 (BC1 of E. arundinaceus) × Neijiang57-416 (commercial sugarcane cultivar) were evaluated for smut resistance using artificial inoculation. The results showed that of 79 tested BC1 and BC2 lines of E. arundinaceus, 10 (12.7%) were highly to moderately resistant to smut. BC1 of E. arundinaceus had more resistant lines than BC2 of E. arundinaceus. Of the 37 tested BC1 lines of E. arundinaceus, seven (18.9%) were highly to moderately resistant, while three (7.1%) of the 42 tested BC2 lines of E. arundinaceus were highly to moderately resistant to smut. The resistant lines identified in this study could be used as sources of smut resistance in sugarcane breeding programs.

High catalytic activity for CO oxidation can be obtained on TiO2 nanotubes (NTs) -supported copper oxide (CuO/TiO2 NTs). But the relatively low thermal stability limits its practical application. Via cerium oxide modification, catalysts with enhanced catalytic activity and higher thermal stability can be obtained. The prepared materials are characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), and temperature-programmed reduction (TPR). Catalytic performance for low-temperature CO oxidation is studied by using a microreactor-GC system. Obtained results indicate that CuO/TiO2 NTs exhibit higher thermal stability and higher catalytic activity for CO oxidation after cerium oxide is added.

A novel alkaline lipase-producing strain 1-7 identified as Acinetobacter calcoaceticus was isolated from soil samples collected from Bohai Bay, China, using an olive oil alkaline plate, which contained olive oil as the sole carbon source. The lipase from strain 1-7 showed the maximum activity at pH 9.0 under 40ºC. One interesting feature of this enzyme is that it exhibits lipase activity over a broad range of temperatures and good stability. It is also stable at a broad range of pHs from 4.0 to 10.0 for 24 h. Its catalytic activity was highly enhanced in the presence of Ca2+, Mg2+ and K+, but partially inhibited by Cu2+, Al3+, Fe3+ , Ba2+and Zn2+. The fact that it displays marked stability and activity in the presence of TritonX-100, Tween-20, Tween-80, SDS, Hydrogen peroxide, Sodium perborate, Sodium hypochlorite, Sodium citrate, Sodium taurocholate, Glycerine and NaCl suggests that this lipase is suitable as an additive in detergent formulations.