Isolation and Purification of Gonyautoxins from Two Strain of Alexandrium minutum Halim

Aim To study isolation and purification of Gonyautoxins from two differentstrains of Alexandrium minutum Halim. Methods Ethanol extracts of the two culture strains ofAlexandrium minutum Halim were fractionated by gel filtration and ion exchange chromatography toobtain gonyautoxins. The toxin profiles were tested by HPLC method. Results Both strains containgonyautoxin-1, gonyautoxin-2, gonyautoxin-3 and gonyautoxin-4. The total gonyautoxin content ofAmtk4 strain is almost 10 times higher than that of Amtk2 strain. Conclusion Alexandrium minutumHalim Amtk4 strain is suitable for the preparation of Gonyautoxins.

Preliminary Study on the Separation of Lysozyme,Ovotransferrin and Ovalbumin from Egg White

[Objective] A study on separation process of lysozyme, ovotransferrin and ovalbumin from egg white. [Method] The proteins were separated by ammonium sul-fates and ion-exchange chromatography. Purity of the proteins was assayed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis （SDS-PAGE）. [Result] The results showed that the proteins were electrophoresis-pure. The specific activity of lysozyme was increased from 144.13 to 2 235 U/mg, and purification factor was 15-fold. Lysozyme recovery rate was estimated to be 15.76%. Bacteriostasis rate of ovotransferrin was 48.84%. [Conclusion] The procedure for separating lysozyme, ovotransferrin and ovalbumin from egg white was simple, fast, low-cost and suitable for industrilization.

Research on Bipolar Membrane Electrodialysis for Ion Exchange of Molecular Sieves

In view of the problems associated with large amount of discharged wastewater and serious pollution in the existing technology for removing sodium species from molecular sieves,this research work introduces the bipolar membrane electrodialysis into the process of removing sodium species from molecular sieves,and proposes a novel method of cleanly removing sodium from molecular sieves.The results show that the technology for removing sodium ions from the molecular sieves with an indirect electrodialysis process is feasible,and can recover Na OH solution.The bipolar membrane electrodialysis is especially suitable for treating the USY,ZSM-5 and Beta molecular sieves with high acid-resistance,and the physicochemical properties and catalytic performance of the prepared molecular sieves are roughly equivalent to those of the ammonium ion-exchange method.In comparison with the ammonium ion-exchange method,the process is clean and environmentally friendly,which consumes less water,and does not discharge wastewater to exhibit a rosy prospect of industrial application.

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＋.