State Key Laboratory of Food Science and Technology, Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, Jiangsu 214122, China.
J Food Sci. 2012 Aug;77(8):M505-15. doi: 10.1111/j.1750-3841.2012.02705.x. Epub 2012 Jul 18.
The production and application of novel β-glucosidase from Trichosporon asahii were studied. The β-glucosidase yield was improved by response surface methodology, and the optimal media constituents were determined to be dextrin 4.67% (w/v), yeast extract 2.99% (w/v), MgSO(4) 0.01% (w/v), and K(2) HPO(4) 0.02% (w/v). As a result, β-glucosidase production was enhanced from 123.72 to 215.66 U/L. The effects of different enological factors on the activity of β-glucosidases from T. asahii were investigated in comparison to commercial enzymes. β-Glucosidase from T. asahii was activated in the presence of sugars in the range from 10% to 40% (w/v), with the exception of glucose (slight inhibition), and retained higher relative activities than commercial enzymes under the same conditions. In addition, ethanol, in concentrations between 5% and 20% (v/v), also increased the β-glucosidase activity. Although the β-glucosidase activity decreased with decreasing pH, the residual activity of T. asahii was still above 50% at the average wine pH (pH 3.5). Due to these properties, extracellular β-glucosidase from T. asahii exhibited a better ability than commercial enzymes in hydrolyzing aromatic precursors that remained in young finished wine. The excellent performs of this β-glucosidase in wine aroma enhancement and sensory evaluation indicated that the β-glucosidase has a potential application to individuate suitable preparations that can complement and optimize grape or wine quality during the winemaking process or in the final wine.
The present study demonstrated the usefulness of response surface methodology based on the central composite design for yield enhancement of β-glucosidase from T. asahii. The investigation of the primary characteristics of the enzyme and its application in young red wine suggested that the β-glucosidase from T. asahii can provide more impetus for aroma improvement in the future.
研究了从里氏木霉中生产和应用新型β-葡萄糖苷酶。通过响应面法提高了β-葡萄糖苷酶的产量，并确定最佳培养基成分为糊精 4.67%（w/v）、酵母提取物 2.99%（w/v）、MgSO4 0.01%（w/v）和 K2HPO4 0.02%（w/v）。结果，β-葡萄糖苷酶的产量从 123.72 U/L 提高到 215.66 U/L。与商业酶相比，研究了不同的酿酒因素对里氏木霉β-葡萄糖苷酶活性的影响。从里氏木霉中提取的β-葡萄糖苷酶在 10%至 40%（w/v）范围内的糖存在下被激活，除葡萄糖（轻微抑制）外，在相同条件下保持比商业酶更高的相对活性。此外，在 5%至 20%（v/v）之间的乙醇浓度也增加了β-葡萄糖苷酶的活性。尽管β-葡萄糖苷酶的活性随 pH 值降低而降低，但在平均葡萄酒 pH 值（pH 3.5）下，里氏木霉的残留活性仍高于 50%。由于这些特性，与商业酶相比，来自里氏木霉的细胞外β-葡萄糖苷酶在水解仍存在于年轻成品酒中的芳香前体方面表现出更好的能力。该β-葡萄糖苷酶在葡萄酒香气增强和感官评价中的出色表现表明，该β-葡萄糖苷酶在葡萄酒酿造过程或最终葡萄酒中具有补充和优化葡萄或葡萄酒质量的潜在应用。
本研究表明，基于中心复合设计的响应面法可用于提高里氏木霉β-葡萄糖苷酶的产量。对酶的主要特性及其在年轻红葡萄酒中的应用的研究表明，未来里氏木霉β-葡萄糖苷酶可为香气改善提供更多动力。
