S-adenosylmethionine is one of very important pharmaceutics because of its biological functions, such as transmethylation, trans-sulfuration and trans-aminopropyl. A strain which producing S-adenosylmethionine was isolated from lees and the optimization of fermentation conditions and medium components were carried out. The medium contains per liter: sucrose 4g, NH4NO3 5g, KH2PO4 0.8g, K2HPO4 0.8g, yeast extracts 3g, DL-methionine 4g, MgSO4·7H2O 0.4g, ZnSO4·7H2O 0.3g, FeSO4·7H2O 0.2g, CaCl2 0.3g, initial pH 5.0, 50mL medium in 500mL flask. The culture was performed at 30℃ and 200rpm for 24h which yielded 1213μg S-adenosylmethionine /mL culture broth.S-adenosylmethionine was extracted by breaking the cellswall using ethyl acetate and 0.35M sulfuric acid and purified by ion exchange chromatograph. γ-polyglutamic acid was purified from fermentation broth of Bacillus subtilis nattor NUST365. Then γ-polyglutamic acid and S-adenosylmethionine were mixtured to prepare γ-polyglutamic acid-adenosylmethionine which was characterized by ultraviolet absorbtion spectrum, high performance liquid chromatograph and nuclear magnetic resonance. The results show there is an interaction between γ-polyglutamic acid and S-adenosylmethionine which indicates γ-polyglutamic acid-adenosylmethionine is made. |