Study On Vanadium Accumulation And Some Biochemical Characteristics Of Saccharomyces Cerevisia

The vanadium is one of the essential trace elements of human body. A large amount ofresearch shows that vanadium plays an important physiological function in animal and thehuman bodies. In addition, vanadium related to withering and death of cell, cancer as wellas nutrition metabolism by acting on the immune system. The shortage of the internalvanadium will cause the metabolism disorder of sugar and fat, and consequently result indiabetes and cardiovascular diseases, while the supply of micro-vanadium in the humanbody will obviously help to treat these diseases. Brewer's yeast is able to assimilate a great number of minerals and trace element intoa nutritious product. In this work, brewer's yeast was used to enrich vanadium by addingNH4VO3into culture media, making inorganic vanadium to be accumulated into cells. From 5 strains of brewer's yeast of stock culture in this laboratory, Saccharo mycesceveisiae RCEF1023 which is suitable for V-rich yeasts fermentation, was selected byresistant screening and flask fermentation. Through liquid culture screening and the orthogonal design experiment ,the recipe offermentive medium was prescribed: 1% glucose, 0. 3% yeast extract, 0.5% peptone , 25%11BX wort. The concentration of vanadium, culture temperature , pH , culture time , inoculmsvolume, volume of medium etc factor were also studied and the primary optimization ofcultivation conditions was selected through fermentation test. The result showed that theoptimal condtions for the enrichment of vanadium into yeast was obtained after 48h at28℃, when inoculms volume was 10% (V/V) with 50mL of culture in 500mL shake flaskswhich was grown in culture fluid containing 40μg/mL V+5. The initial pH was adjusted 6.0.Under the optimal cultivation conditions, the biomass (dry weight) of 100mL fermentationreached 0.663g and enrichment quantity of vanadium was about 587.6μg/g. It was evidentthat the concentration of vanadium, pH and volume of medium greatly affected thebiomass and vanadium content of the brewer's yeast. In order to test the content of the organic vanadium in vanadium-rich brewer's yeast,adopting lixiviation process to separate inorganic vanadium and organic vanadium fromthe vanadium yeast , so the content of organic vanadium in the vanadium yeast could beaccurately determined. The content of organic vanadium in the test was 474.9μg/g.Study on the autolysis condition of vanadium-rich brewer's yeast turned out that theoptimal conditions for antolysis were pH 7.0, 55℃and 24h for acid-heat shiver 3mol/LHCl, 6min soaking, and 3min.heating No significant difference was observed betweenthe two methods in their shiver effect. In addition, with ultraviolet spectrometry scanning within 200~600nm measurementof the ordinary yeast and vanadium-rich yeast, the vanadium-rich yeast has a characteristicabsorption in 311nm. With the determination of infrared spectrometry, the vanadium yeasthas a characteristic absorption in 1794cm-1. The raw protein was further separated into two fractions by Sephadex G-100 gelchromatography. The yield rates of FractionⅠand FractionⅡwere 8.2%,16.0%.Thevanadium content of FractionⅠand FractionⅡwas 1.66μg/mg and 8.08μg/mg. Analyzing of 16 kinds of amino acid, it turned out that the content of Met and Phe invanadium-rich yeast was higher than that in normal yeast. This Experiment has also compared the absorption and utilization betweeninorganic vanadium and vanadium yeast by using moina macrocpa. Taking moinamacrocpa as the animal's model, studying the influence of vanadium yeast and inorganicvanadium from the pharmacodynamics aspect . The result of the toxic test shows thatvanadium-rich brewer's yeast can effectively reduce the toxicity of the vanadium.