PECTIN LYASE IS A KEY ENZYME IN THE MACERATION OF POTATO-TUBER

The maceration of potato tuber (Solanum tuberosum cv Bintje) by techni cal enzyme preparations was examined with the aid of fluorescence micr oscopy using fluorescein diacetate as a dye. Treatment with Pectinex U ltra-SP-L from Aspergillus aculeatus resulted in a higher release of s ingle viable cells and smaller clumps of cells than treatment with Roh ament P from Aspergillus niger. Fractions with high pectin lyase and l ow polygalacturonase activity obtained by anion exchange chromatograph y of Pectinex Ultra SP-L showed the highest degree of maceration. When two different cloned polygalacturonases (PG1 and PG2) and a cloned pe ctin lyase (PL1) from A aculeatus were examined, the highest degree of maceration was observed with PL1. In conclusion, pectin lyase is prob ably the main enzyme in Pectinex Ultra-SP-L responsible for the macera tion of potato tuber.