菌株MP-24产单宁酶的条件优化和生物转化茶多酚
发布时间：2018-10-09 20:27
【摘要】：单宁酶,即单宁酰基水解酶(E.C.3.1.1.20),可以水解单宁酸中的酯键,将单宁酸完全水解为没食子酸和葡萄糖。单宁酶被广泛应用于食品、饲料、制药,饮料、酿造和化工等行业。本研究对产单宁酶菌株MP-24进行初步鉴定,优化其固体发酵培养基配方和发酵条件,并应用于茶多酚和茶汤的生物转化,采用HPLC和LC-MS分析法分析单宁酶转化产物,检测转化产物的抗氧化活性。对菌株MP-24进行结合形态学观察和ITS序列分析之后,初步鉴定其为青霉属(Penicillium)真菌。对该菌株固体发酵产单宁酶的固体发酵培养基配方和培养方法进行单因素-响应面优化过后的单宁酶固体发酵培养基和培养条件为：茶叶4.5 g,单宁酸0.5 g,α-乳糖0.25g,无机盐溶液(1.070% NH4Cl,4.1%(w/w)MgSO4·7H2O,0.1% NaCl, pH 6.057)9.45 mL,接种量2.0 mL,28℃发酵96h。最佳发酵酶活的预测值为31.28962 U/gds.实测值为30.37 U/gds。同优化前产率10.42 U/gds相比,提高到了约2.91倍。利用菌株MP-24固体发酵产生的单宁酶对茶多酚进行生物转化,发现其对茶汤转溶效果显著,明显提高茶汤澄清度。用HPLC方法和LC-MS分析方法分析其转化产物,之后用抗超氧阴离子自由基的测定、羟自由基测定、DPPH自由基清除率的测定和总抗氧化能力(T-AOC)测定等4种抗氧化活性分析方法分析其转化产物的抗氧化活性,经过生物转化的茶汤和茶多酚的抗氧化活性有一定程度的提高。本研究鉴定了一株从黑茶中分离筛选的产单宁酶菌株MP-24,优化了其固体培养基与培养条件,明确了MP-24所产单宁酶对茶多酚有一定的转化作用,并可提高茶汤的澄清度与抗氧化活性。本研究的结果为单宁酶的生产和应用提供了理论参考和基础。
[Abstract]:Tannase (E.C.3.1.1.20) can hydrolyze ester bond in tannic acid and completely hydrolyze tannic acid into Gallic acid and glucose. Tannase is widely used in food, feed, pharmaceutical, beverage, brewing and chemical industries. In this study, the tannase producing strain MP-24 was preliminarily identified, its solid fermentation medium formulation and fermentation conditions were optimized, and applied to the biotransformation of tea polyphenols and tea soup. HPLC and LC-MS analysis were used to analyze the transforming products of tannase. The antioxidant activity of the transformed product was determined. The strain MP-24 was identified as Penicillium (Penicillium) after morphological observation and ITS sequence analysis. The formula and culture method of solid fermentation medium for producing tannase by solid fermentation of the strain were optimized by single factor-response surface, and the culture conditions were as follows: tea 4.5 g, tannic acid 0.5 g, 伪 -lactose 0.25 g, tea 4.5 g, tannin 0.5 g, 伪 -lactose 0.25 g. Inorganic salt solution (1.070% NH4Cl,4.1% (w / w) MgSO4 7H 2O 0.1% NaCl, pH 6.057) was inoculated with 9.45 mL, for 96 h at 2.0 mL,28 鈩，
本文编号：2260671
[Abstract]:Tannase (E.C.3.1.1.20) can hydrolyze ester bond in tannic acid and completely hydrolyze tannic acid into Gallic acid and glucose. Tannase is widely used in food, feed, pharmaceutical, beverage, brewing and chemical industries. In this study, the tannase producing strain MP-24 was preliminarily identified, its solid fermentation medium formulation and fermentation conditions were optimized, and applied to the biotransformation of tea polyphenols and tea soup. HPLC and LC-MS analysis were used to analyze the transforming products of tannase. The antioxidant activity of the transformed product was determined. The strain MP-24 was identified as Penicillium (Penicillium) after morphological observation and ITS sequence analysis. The formula and culture method of solid fermentation medium for producing tannase by solid fermentation of the strain were optimized by single factor-response surface, and the culture conditions were as follows: tea 4.5 g, tannic acid 0.5 g, 伪 -lactose 0.25 g, tea 4.5 g, tannin 0.5 g, 伪 -lactose 0.25 g. Inorganic salt solution (1.070% NH4Cl,4.1% (w / w) MgSO4 7H 2O 0.1% NaCl, pH 6.057) was inoculated with 9.45 mL, for 96 h at 2.0 mL,28 鈩，
本文编号：2260671
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