| 摘要: |
| 【目的】 优化酒酒球菌中β-葡萄糖苷酶的产酶条件，分析β-葡萄糖苷酶的性质，为将其应用于葡萄酒生产提供参考。【方法】 对12株酒酒球菌进行β-葡萄糖苷酶活性测定，选择其中β-葡萄糖苷酶活性最高的菌株CS-7b作为试验菌株，并以商业菌株31-DH为对照，以菌株催化底物对硝基苯酚-β-葡萄糖苷(p-NPG)生成对硝基苯酚的速度衡量β-葡萄糖苷酶活性高低。然后通过单因素试验和正交试验对菌株产β 葡萄糖苷酶的条件进行优化，并探究葡萄酒环境相关因素(pH值、温度、乙醇体积分数、葡萄糖质量浓度)对β 葡萄糖苷酶活性的影响。【结果】 单因素试验确定菌株产β-葡萄糖苷酶培养基的最佳pH值为6.8，最佳碳源为麦芽糖，最佳氮源为酵母浸粉，正交试验进一步确定了各种成分的最佳配比，即每升液体培养基中含麦芽糖7 g，酵母浸粉20 g，MgSO4·7H2O 0.1 g，盐酸半胱氨酸0.5 g，MnSO4·4H2O 0.03 g，培养基起始pH值为6.8,在此条件下，β-葡萄糖苷酶活性可由0.359增加到1.319 μmol/(g·min)。β-葡萄糖苷酶的酶学性质为：最适pH值为5.0，最适温度为37 ℃；当乙醇体积分数大于4%、葡萄糖质量浓度大于1 g/L时，β-葡萄糖苷酶活性开始受到抑制。【结论】 酒酒球菌CS-7b在葡萄酒环境的pH及乙醇体积分数条件下仍可保持一定的β-葡萄糖苷酶活性。 |
| 关键词: 酒酒球菌 β-葡萄糖苷酶 产酶条件优化 酶学性质 |
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| 基金项目:国家“十二五”科技支撑计划项目（2012BAD31B07）；现代农业产业技术体系建设专项（nycytx-30-ch-03） |
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| Optimization of β-glycosidase production of Oenococcus oeni and its enzymology properties |
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WANG Ling,BO Xiao,WCHEN Qiling,et al
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| Abstract: |
| 【Objective】This study optimized the β-glycosidase production and characterized its enzymology properties to provide basis for its application in wine making. 【Method】 Oenococcus oeni CS-7b was selected among twelve tested strains because of its highest enzyme activity.The commercial strain 31 DH was used as control.The enzyme activity was measured according to the production rate of p-nitrophenol (p-NP) with p-nitrophenylβ-glucoside (p-NPG) as the substrate.The enzyme production conditions were optimized by single factor experiment and orthogonal experiment.The effects of environment factors (pH,temperature,alcohol and glucose content) were also investigated.【Result】Single factor experiment showed that the best conditions were pH value 6.8,carbon source maltose,and nitrogen source yeast powder.Then orthogonal experiment determined the best amounts:1 L medium should contain 7 g maltose as carbon source,20 g yeast extract as nitrogen source,MgSO4·7H2O 0.1 g,cysteine hydrochloride 0.5 g,MnSO4·4H2O 0.03 g,and initial pH 6.8.Under optimal conditions,the enzyme activity was increased to 1.319 μmol/(g·min) from the initial of 0.359 μmol/(g·min).Enzymology properties were:β-glycosidase was optimal at pH 5.0 and 37 ℃ and the activity was strongly inhibited by higher concentrations of alcohol (4%) and glucose (1 g/L).【Conclusion】Strain CS-7b retained high glycosidase activity under wine conditions of pH and temperature,suggesting that β-glycosidase activity of Oenococcus oeni had good application potential in wine making industry. |
| Key words: Oenococcus oeni β-glycosidase optimization enzymology properties |
