嗜酸真菌Bispora sp.MEY-1酸性糖苷水解酶的产酶优化及在动物饲料中的应用

Production of Multiple Acidic Glycoside Hydrolases in Acidophilic Fungus Bispora sp.MEY-1 and Their Potential Application in Animal Feed

嗜酸真菌Bisporasp.MEY-1可以分泌多种酸性糖苷水解酶。以不同的农业废弃物和副产品为碳源诱导该菌产酶以提高液体发酵效率并降低生产成本,结果表明0.5%的魔芋粉和9%的麦麸/玉米芯粉/豆粕混合物诱导效果最佳,木聚糖酶、葡聚糖酶、甘露聚糖酶、纤维素酶、淀粉酶、果胶酶、α-半乳糖苷酶、β-半乳糖苷酶、β-葡萄糖苷酶的产量分别为15、50、3.7、5.7、3.2、0.6、3.4、0.1、1.8U·ml-1。菌株MEY-1最适产酶pH为3,温度为30℃。与优良的商业糖苷水解酶生产菌株Trichoderma reesei RUT C30相比,菌株MEY-1分泌的糖苷水解酶偏酸,且在模拟胃肠道条件下保留了更多的木聚糖酶和葡聚糖酶活性,可降低大麦/豆粕饲料的黏度,在动物饲料工业中具有良好的应用前景。

Acidophilic fungus Bisporasp.MEY-1is a multiple acidic glycoside hydrolase producer.To increase fermentation efficiency and reduce production cost,we induced the simultaneous synthesis of various enzymes in submerged cultivation with different agricultural waste and by-products as carbon and nitrogen sources.When the content of konjac flour was 0.5%and the gross content of wheat bran,corncob powder and soybean meal was 9%,high activities of xylanase(15U·ml-1),β-glucanase(50U·ml-1),β-mannanase(3.7U·ml-1),CMCase(5.7U·ml-1),amylase(3.2U·ml-1),pectinase(0.6U·ml-1),α-galacosidase(3.4U·ml-1),β-galacosidase(0.1U·ml-1),andβ-glucosidase(1.8U·ml-1)were achieved.The optimal pH and temperature for enzyme production were determined to be pH 3and 30℃,respectively.Compared with the excellent commercial glycoside hydrolase producer Trichoderma reesei RUT C30,the glycoside hydrolase complex fromBisporasp.MEY-1showed more acidic pH optima,and retained more xylanase and glucanase activities and reduced more viscosity of barley-soybean meal diets under simulated gastric conditions.These properties make Bisporasp.MEY-1apotential strain for extensive application in animal feed.