Karboune Salwa, Geraert Pierre-André, Kermasha Selim
Department of Food Science and Agricultural Chemistry, McGill University, 21,111 Lakeshore, Ste. Anne de Bellevue, Quebec H9X 3V9, Canada.
J Agric Food Chem. 2008 Feb 13;56(3):903-9. doi: 10.1021/jf072847l. Epub 2008 Jan 5.
The presence of endo-1,4-beta-D-glucanase, cellobiohydrolase, and beta-glucosidase activities in a multi-enzymatic complex system from Penicillium funiculosum was investigated. The interesting feature of these enzymes is their synergistic action for the hydrolysis of the native cellulose into glucose units. Both endo-1,4-beta-D-glucanase and cellobiohydrolase showed broader pH activity profiles, with pH optima of 4.0 and 4.0-5.0, respectively. However, beta-glucosidase activity showed a narrow pH-activity profile, with an optimum pH of 4.5. The different cellulolytic activities were stable in the acidic pH range of 2.5-6.0 and showed a similar optimal temperature of 60 degrees C. Although beta-glucosidase has shown a close catalytic efficiency as that of endo-1,4-beta-D-glucanase, its thermal stability was lower. However, the thermal stability profile of cellobiohydrolase was close to that of endo-1,4-beta-D-glucanase. The results also revealed the presence of high levels of endo-1,3-1,4-beta-D-glucanase, endo-1,3-beta- d-glucanase, and pectinase activities in the multi-enzymatic cellulolytic complex system. Moreover, the investigated multi-enzymatic complex system was effective in degrading the nonstarch polysaccharides of soybean meal.
研究了绳状青霉多酶复合体系中内切-1,4-β-D-葡聚糖酶、纤维二糖水解酶和β-葡萄糖苷酶的活性。这些酶的有趣之处在于它们协同作用将天然纤维素水解成葡萄糖单元。内切-1,4-β-D-葡聚糖酶和纤维二糖水解酶均表现出较宽的pH活性谱,最适pH分别为4.0和4.0 - 5.0。然而,β-葡萄糖苷酶活性表现出较窄的pH活性谱,最适pH为4.5。不同的纤维素分解活性在2.5 - 6.0的酸性pH范围内稳定,且显示出相似的最佳温度60℃。尽管β-葡萄糖苷酶的催化效率与内切-1,4-β-D-葡聚糖酶相近,但其热稳定性较低。然而,纤维二糖水解酶的热稳定性谱与内切-1,4-β-D-葡聚糖酶相近。结果还揭示了在多酶纤维素分解复合体系中存在高水平的内切-1,3-1,4-β-D-葡聚糖酶、内切-1,3-β-D-葡聚糖酶和果胶酶活性。此外,所研究的多酶复合体系在降解豆粕非淀粉多糖方面是有效的。