Inducing and isolation of antibacterial peptides from oriental fruit fly, Bactrocera dorsalis Hendel

One antibacterial activity fraction from an immunized dipteran insect, Bactrocera dorsalis, was isolated and purified by prepurification, ion-exchange chromatography, gel filtration chromatography and reverse-phase high performance liquid chromatography （HPLC）. The final purified fraction was checked on the Smart system HPLC and was judged as a pure fraction. The results of physical and biological analysis revealed that this fraction is heat stable and showed strong activities against Gram-positive bacterial growth. It possesses antibicrobial peptide properties and is worth further investigation.

Purification and crystallization of xylitol from fermentation broth of corncob hydrolysates

Xylitol,a five-carbon sugar alcohol,is a valuable sugar substitute,and widely used in the pharmaceutical,odontological and food industry due to its interesting properties.In the past decades,the xylitol industry has grown rapidly and more attention has been focused on xylitol purification,which possesses an important proportion of the whole industry.In our paper,the purification and crystallization of xylitol fermentation broth by biotechnology using corncob hydrolysates as substance were studied.An initial xylitol fermentation broth was decolored with activated carbon(1%M-1,60℃,165 rpm),desalted with a combination of two ionexchange resins(732 and D301),and residual sugars were separated with UBK-555(Ca^(2+)).Then the solution was vacuum-concentrated up to supersaturation(750 g/L xylitol).After adding 1%xylitol crystal seeds,the supersaturated solution was cooled to-20℃for 48 h.The crystalline xylitol of a regular tetrahedral shape with purity 95%and crystallization yield 60.2%was obtained from the clarified xylitol fermentation broth.An intact,economical and environmental-friendly route of purification and crystallization of xylitol from fermentation of corncob hydrolysates was obtained,and its experimental procedure and data provided a sound basis for large-scale industrial production.

Existing form of Mo(Ⅵ)in acidic sulfate solution

The existing form of molybdenum in acidic sulfate solution was studied by means of ion exchange, infrared （IR） spectra and X-ray photoelectron spectroscopy （XPS）. The results indicate that the anionic molybdenum species are predominant in acidic sulfate solution, and Mo（VI） can combine with sulfate radical to form heteropoly acid anions [Mo205（804）2]2- and [MoO2（HSO4）4]2-. With the decrease in solution pH from 1.92 to 0.06, the existing form of Mo（VI） changes from MovO21（OH）3^3- to [Mo205（S04）2]2- and then becomes [MoOz（HSO4）4]2-, which results in the decrease in the resin adsorption capacity for molybdenum.

Removal of Zn2＋ from aqueous solution by biomass of Agaricus bisporus

Abstract Biosorption of Zn2＋ from aqueous solutions by biomass of Agaricus bisporus was investigated. The removal rates of Zn2＋ by A. parameters （e.g., solution pH, initial Zn2＋ concentration） were A. bisporus＇s biosorption by bisporus under different bio-sorbent dosage and studied. The inhibition of anionic ligands EDTA （Ethylene Diamine Tetraacetic Acid）, acetate and citrate） implied that EDTA and citrate might be used as eluting reagents. Regular and simultaneous solution pH change and light metal ions release after biosorption indicated that an ion exchange mechanism was involved. From FT-IR （Fourier Transform Infrared） spectroscopy, the main functional groups participated in biosorption were found. Biosorption of Znz＋ byd. bisporus could be well described by the Freundlich and Langmuir models. In conclusion, the biomass of A. bisporus showed high potential for the treatment of wastewater containing Zn2＋.