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A phytase from Candida krusei WZ-001 isolated from soil was purified to electrophoretic homogeneity by ion-exchange chromatography, hydrophobic interaction chromatography, and gel filtration. The phytase is composed of two different subunits with molecular masses of 116 kDa and 31 kDa on SDS-PAGE (or 120 kDa and 30 kDa on gel chromatography), with the larger subunit having a glycosylation rate of around 35%. The phytase has an optimum pH of 4.6, an optimum temperature of 40 degrees C and a pI value of 5.5. The phytase activity was stimulated by 2-mercapto-ethanol and dithiothreitol (DTT), and inhibited by Zn2+, Mg2+, iodoacetate, pI value of 5.5. The phytase activity was stimulated by 2-mercapto-ethanol ethanol and dithiothreitol (DTT), and inhibited by Zn2+, Mg2+, iodoacetate, p-chroloromercuribenzoate (pCMB) and phenylmethylsulfonyl fluoride (PMSF). The phytase displayed a broad substrate specificity and the K(m) for phytate was 0.03 mM. Phytate was sequentially hydrolyzed by the phytase. Furthermore, 1D and 2D NMR analyses and bioassay of myoinositol indicated that the end hydrolysis product of phytate was myoinositol 2-monophosphate.

Tris-(8-quinolinolato) aluminum (AlQ 3 ) organic nanoparticles with an average diameter 20 nm were prepared through a reprecipitation method. The AlQ 3 nanoparticles are spherical and the average particle size does not change by varying the aging time. The photoluminescent and electroluminescent properties were investigated via the AlQ 3 nanoparticles and the device based on the AlQ 3 nanoparticles, respectively. Blue shift of both the photoluminescence and electroluminescence spectra for the AlQ 3 nanoparticles was observed. With increasing the driving bias, the maximum EL emission peak of the AlQ 3 nanoparticles was shifted to longer wavelength. The maximum luminance and luminous efficiency of the AlQ 3 nanoparticle-based device are about 600 cd/m 2 at driving bias 16Vand 0.19 cd/A at a current density of 150 mA/cm 2 , respectively. The obvious quantum size effect of electro-luminescence devices with the AlQ 3 nanoparticles has been proved, which will open a useful route and new studying field of organic electronic devices, and the study of the fundamental process connecting both of those more conventional classes of materials, i.e., organic molecular crystals.