| Fuzhuan Brick Tea is one kind of the post fermentation tea which was formed by unique fermentation process through multipling dominant bacteria,many scholars believe that the ‘Jinhua’ fungi is Eurotium cristatum. Eurotium cristatum owns unique metabolism process which has some health protection functions of increasing the effect of appetite, lowering blood pressure and dilute lipid. At the same time, different nutrients substances and external culture conditions will have an effect on the growth of Eurotium cristatum and fungus process of Fuzhuan Brick Tea, it leads to the changes of functional ingredients and the quality of the Fuzhuan Brick Tea.The sporulation rule and the change of yellow pigment and the relationship between sporulation and yellow pigment of the Eurotium cristatum under different nutrients and culture conditions is studied in this paper,using the Eurotium cristatum. combined with thin layer chromatography(TLC),high performance liquid chromatography(HPLC) and infrared spectrum(IR) on the yellow pigment and lipid-lowering substances is studied. The following results are obtained.1.Combined with colony morphology, colony diameter, absorbance of yellow pigment, the number of sexual spores and asexual spores of the Eurotium cristatum, the optimum condition was obtained through changing CZG medium carbon source(sucrose and glucose) and the concentration of carbon source(1%,3%, 5%, 7%, 10%-90%), nitrogen source(sodium nitrate, ammonium nitrate,ammonium sulfate) and nitrogen source concentration(0.1%, 0.3%, 0.5%, 0.7%,1%, 3%-11%), inorganic salt(sodium chloride, potassium chloride) and inorganic salt concentration(1%-17%), culture temperature(15℃, 20℃, 25℃,28℃, 32℃, 35℃, 40℃) and medium p H(3-9) which produced sporulation rule and yellow pigment of Eurotium cristatum in different conditions.The single factor and orthogonal experiments showed that the best condition was 3%of sucrose, 0.7% of ammonium nitrate, 3% of potassium chloride, temperature of28℃, p H was 7. Meanwhile, the content of yellow pigment was proportional to the number of sexual spore, however, it was inversely proportional to the number of asexual spores. 1%-20% of carbon source, 0.1%-0.7% of nitrogen source,1%-5% of inorganic salt, 15℃-28℃of culture temperature, p H was 7, the reproduction of the Eurotium cristatum is mainly to sexual spore which is not almost asexual spores; however, 20%-90% of carbon source, 0.7%-11% of nitrogen source, 5%-15% of inorganic salt, 15℃-28℃of culture temperature, p H was 3-7 and 7-9, the reproduction of the Eurotium cristatum is mainly to producing asexual spore, and the number of asexual spores is more than sexual spores.2. Liquid Fermentation Technology was used on the research of lovastatin,which was a kind of lipid-lowering substance produced by the Eurotium cristatum. With lovastatin(chromatographically pure) as reference, the analysis of TLC and HPLC showed that the content of extract of Eurotium cristatum was6.199mg/L. So the Eurotium cristatum had the ability to produce lovastatin.3. The study on yellow pigment produced by Eurotium cristatum(1) The yellow pigment was extracted by using ligroin. After the processes of filtering and vacuum concentration, crude yellow pigment was extracted with a product rate of 1.25%. The bacteriostatic test of yellow pigment showed that yellow pigment had a significant inhibitory effected on Staphylococcus aureus, and the diameter of bacteriostasis circle was(10.57 ± 0.35)mm, the minimal inhibitory concentrations(MIC) was less than 0.5%; however the inhibitory effected on Escherichia coli was not significant, whose bacteriostasis circle diameter was(0.70±0.31)mm and the MIC was greater than 3%.(2) Thin-layer chromatography was used on the isolation and purification of crude yellow pigment. The results showed that the optimal eluent for thin-layer was a compound of petroleum ether,acetone,methanol with a ratio of 10:1:2.After chromatographic development, 6 stripes were showed whose Rf value in turn was 0.84, 0.48, 0.40, 0.38, 0.30, 0.24. Then the secondary chromatographic development was executed with the same eluent on the 3nd stripe(Rf 0.40) and the 4th stripe(Rf 0.38). As a result, 2 stripes was expended from the 3nd stripe whose Rf value were 0.64, 0.34, and 3 stripes was expended from the 4th stripe whose Rf value were 0.74, 0.45, 0.31.(3) The 5 stripes separated secondarily were scanned by UV scanning and infrared scanning. The results of UV scanning showed that all of the 5 pigments has absorption peak in the vicinity of 213 nm, besides, the pigment with a Rf value of 0.64 had 3 absorption peaks in the range of 250-300 nm and the other 4pigments contained 2 absorption peaks in this range. Excluding the pigment who had a Rf value of 0.34, all the other 4 pigments had absorption peaks in the range above 300 nm. On the other side, the IR results showed that the 4-1pigment contains O–H, –CH3, –CH2, C=O, C–O, 4-1pigment may be the anthraquinone derivatives, 4-2 pigment contains O–H, –CH3, –CH2, C=O and C=C of polyaromatic ring, 4-2 pigment may be the heterocyclic substances, the 4-3pigment contains O–H, –CH3, C=O, C–O, C–N, 4-3 pigment may be the amide class material, The 3-1 pigment contains O–H, –CH3, C=O, C–O, 3-1 pigment may be the phenolic substances. |
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