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Conditions and Activity Analysis of Cell Wall Degrading Enzymes Produced from Corynespora cassiicola of Brown Spot of Cucumber |
LIU Zhi-heng, QI Ye, HUANG Xin-yang, YANG Hong, HOU Yue, ZHANG Rui |
College of Plant Protection, Shenyang Agricultural University, Shenyang 110161, Liaoning, China |
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Abstract A series of cell wall degrading enzymes(CWDEs)including polygalacturonase(PG), polymethyl-galacturonase(PMG), polygalacturonic acid trans-eliminase(PGTE), pectin methyl- trans-eliminase(PMTE)carboxymethyl cellulase(Cx)and β-glucosidase were found both in vitro and vivo from Corynespora cassiicola of brown spot of cucumber. Based on the cell wall degrading enzymes produced in vitro conditions, in vivo after inoculation of bacteria cell wall-degrading enzymes and in vivo produced outside the cell wall-degrading enzyme activity comparison study, the results show that every kind of cell wall degrading enzyme has a specific optimal culture conditions. Shake culture make more for the production of cell-wall degradation compared to the stationary culture. The activities of Cx and β- glucosidase reached a peak when cultured 9 d, PG and PMG reached a peak when cultured 12 d, while PGTE and PMTE reached a peak when cultured 15 d. PG and PMG showed maximum activities at 25 ℃ culture temperature. PGTE, PMTE, Cx and β-glucosidase showed maximum activities at 28 ℃ culture temperature. PG, PMG, Cx and β-glucosidase showed maximum activities at culture pH 6. PGTE and PMTE showed maximum activities at culture pH 8. Four kinds of pectinase showed maximum activities in the third day after inoculation. Two kinds of cellulase showed maximum activities in the fifthday after inoculation. The activity of cell wall degrading enzymes in vivo and in vitro was significantly different.
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Received: 06 November 2010
Published: 06 January 2011
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