茶梗固态生料发酵产单宁酶研究

为促进茶梗的高效利用,对黑曲霉利用茶梗固态生料发酵生产单宁酶进行初步研究。结果表明：生料发酵产酶量是熟料发酵方式的3.2倍;茶梗中外加单宁酸对产酶没有明显影响,同时添加无机盐和碳氮源对产酶具有协同效应;蔗糖为产酶最佳碳源,但在产酶初期会对单宁酶的合成产生一定的抑制作用;氯化铵为产酶最佳氮源,在培养基中添加氯化铵既可提前单宁酶合成的时间,又可显著提高酶产量。添加质量分数为7%的蔗糖和氯化铵获得最高酶产量23.6 U·g^-1。试验结果为茶梗固态生料发酵产单宁酶奠定了一定的理论基础,并有助于促进对茶梗的规模化开发和利用。

Tannase Production from Tea Stalks under Non-heat-treated Solid State Fermentation

The tannase production from Aspergillus niger by non-heat-treated solid state fermentation were investigated using tea stalks as substrate. The results showed that non-heat-treated solid state fermentation stimulated the production of tannase by 3.2-fold, when compared to that of heat-treated group. Supplementation with tannic acid was confirmed to have no influence on tannase production. Meanwhile, additional inorganic salts, carbon and nitrogen sources showed synergistic effect on tannase formation. Sucrose supplementation obtained maximum tannase yield, but the enzyme productivity in the initial stage of fermentation was decreased. Additional ammonium chloride played an important role in tannase synthesis process. It not only increased tannase production, but also shortened the fermentation period observably. Moreover, being supplemented with 7% sucrose and ammonium chloride obtained highest tannase production (23.6 U·g^-1). These results demonstrated that using tea stalks as substrate to produce tannase by non-heat-treated solid state fermentation is a good choice, which can provide the theory basis for further study of tannase production. Meanwhile, it will help to promote the large-scale exploitation of tea stalks and to increase the economic value of this agro-residue.