马铃薯早疫病病菌产生细胞壁降解酶的条件研究

Study on conditions of cell wall degrading enzymes produced from Alternaria solani

为明确马铃薯早疫病病菌产生细胞壁降解酶的条件,采用液体培养基培养病菌。结果表明,病菌在改良的Marcus液体培养基中能产生多聚半乳糖醛酸酶(PG)、果胶甲基半乳糖醛酸酶(PMG)、纤维二糖水解酶(Cx)和β-葡萄糖苷酶(βG)细胞壁降解酶。其中,果胶酶(PG、PMG)的活性较高,纤维素酶(Cx、βG)的活性较低。病菌产生果胶酶的适宜条件为培养液初始p H为4.0,30℃持续振荡培养4 d,纤维素酶初始p H为5.0,25℃持续振荡6 d。

Production conditions of cell-wall degrading enzymes from Alternaria soloni of potato early blight were studied by pathogen inducing and culture with improving Marcus liquid medium. The results showed that a series of cell-wall de- grading enzymes from Alternaria solani could be induced to produce, such as polygalacturonase （PG）, pectin methyl- galacturonase （PMG）, cellobiohydrolase （Cx） and β-glucosidase （βG）. Enzyme activity of PG and PMG were significantly higher than that of Cx and βG. Optimal conditions of pectinase （PG and PMG） production were 30 ℃, pH 4.0 and shak- ing cultivation for 4 days. Optimal conditions of cellulase （Cx and βG） production were 25 ℃, pH 5.0 and shaking culti- vation for 6 days.