哈茨木霉CGMCC 2979生物转化栀子中的京尼平苷制备京尼平

采用微生物直接转化药材的方法，将栀子中的京尼平苷转化为京尼平，无需糖苷酶和京尼平苷的制备. 在培养温度为30 ℃，pH 6.1以及栀子载量为80 g/L的条件下，48 h京尼平苷的转化率为97.8%. 转化后的京尼平通过XAD-16N大孔树脂偶联硅胶层析的方法，制备得到纯度大于95%的京尼平，收率为62.3%. 在催化、转化机制研究中，从哈茨木霉CGMCC2979的发酵液中分离得到了分子量为74.4 kDa的京尼平苷β-葡萄糖苷酶，该酶最优催化条件为50 ℃和pH 4.0-5.0. K_m和V_max分别为3.6 mmol/L和775 μmol/h/mg蛋白. 本文提供了一种简便、高效制备京尼平的新方法.

Biotransformation of geniposide in Gardenia jasminoides to genipin by Trichoderma harzianum CGMCC 2979

Trichoderma harzianum (T. harzianum) CGMCC 2979 was used to transform the geniposide in Gardenia jasminoides (G. jasminoides) to genipin, dispensing the use of purified enzyme and the extraction of geniposide from the raw material. At 30 ℃, pH 6.1, and an initial G. jasminoides concentration of 80 g dried fruit per liter of medium, the geniposide-to-genipin conversion rate reached 97.8% after 48 h of fermentation. The genipin was purified from the fermentation broth by a combined method of XAD-16N-resin and silica-gel chromatography, yielding a total recovery of 62.3%. A 74.4-kDa geniposide-β-glucosidase implicated in the transformation of geniposide to genipin was purified from T. harzianum CGMCC 2979. It had optimum activity at 50 ℃ and pH 4.0-5.0. The K_m and V_max of the enzyme for geniposide were 3.6 mmol/L and 775 μmol/h/mg protein, respectively. The simple, direct, and efficient biotransformation of geniposide in G. jasminoide to genipin by T. harzianum CGMCC 2979 that is described in this study could represent an alternative and effective method for producing genipin.