Studies On Cultivation Of Chromium-enriched Spirulina Platensis And Inhibition Of Its Proteins On α-Glucosidase Activity

In this paper, Spirulina platensis was used as experimental material. The effects of chromium (Ⅲ) with different concentration and adding method of on the growth of Spirulina platensis were investigated. And the cultivation of chromium-enriched Spirulina platensis was optimized by orthogonal experimental design method. The combination of chromium (Ⅲ) and Spirulina platensis was analysed by Atomic emission spectrum and Infrared spectrum. Ammonium sulfate precipitation method and Sephadex gel column chromatography were used to extract proteins from chromium-enriched Spirulina platensis. And then the inhibition on a-glucosidase activity for these proteins was tested. The main results were as follows:(1) The effects of chromium (Ⅲ) with different concentration and adding method of on the growth of Spirulina platensis were investigated. On the base of the single factor experiments, the method of orthogonal experimental design with three factors and three levels was adopted. The optimal combination of chromium (Ⅲ) concentration,adding method and medium pH depended on experimental intention. To improve the growth of Spirulina platensis, the optimal cultivation is:300mg/L chromium concentration (CrCl3·6H2O), six times adding method,9pH.(2) Inductively coupled plasma atomic emission spectrometer and Infrared spectroscopy were used to analyse the combination of chromium (Ⅲ) and Spirulina platensis. During the bioaccumulated process of chromium (Ⅲ) by Spirulina platensis,70.2%are turned into organic chromium (Ⅲ). Chromium in total protein is68.4%of organic chromium. It is found that chromium has a combination with Spirulina platensis, and it mainly combines with the protein. Compared infrared spectra of diagram, the effects of chromium (Ⅲ) enrichment on the algal cell molecular functional group structure were investigated. It is found that telescopic vibration of Cr-O made absorption peaks shifted from536.00cm-1to574.81cm-1, but other functional peaks were without displacement. These results indicated that the chromium enter into the algal cells without hurt in the molecular functional group structure. (3) Different saturation ammonium sulfate precipitation method and Sephadex G-200column chromatography were used to extract proteins from chromium-enriched Spirulina platensis. And then the chromium content in protein and the inhibition on a-glucosidase activity for these proteins were tested. The protein which was extracted by50%saturation ammonium sulfate on a-glucosidase activity is higher than the others, its IC50is about69.87mg/mL. The experimental results showed that differente kinds of protein could bond chromium to different extents, and have inhibition on a-glucosidase activity differently. The inhibitory effect of protein on a-glucosidase is related to the type and concentration of the protein. It has no direction relation with the content of protein and chromium.