Hydrolysis of the potato glycoalkaloid alpha-chaconine by filamentous fungi.
Three strains of filamentous fungi have been isolated from potato sprouts to obtain an enzyme degrading the glycoalkaloids. All of the strains hydrolyzed alpha-chaconine and not alpha-solanine when grown on the sprouts. From strain HP341, identified as Plectosphaerella cucumerina, the enzyme hydrolyzing alpha-chaconine was purified on columns of DEAE-Toyopearl and Phenyl-Toyopearl. The partially purified enzyme hydrolyzed alpha-chaconine to beta1-chaconine but not to beta2- or gamma-chaconine, suggesting that the enzyme is a rhamnosidase specific for the hydrolysis of the rhamnose (C1-C4) glucose linkage in alpha-chaconine. Conversion of alpha-chaconine to beta1-chaconine may be the first step of detoxification for filamentous fungi to grow on potato sprouts that accumulated antifungal alpha-chaconine.
Oda
Yuji
Y
Department of Upland Agriculture Research, National Agricultural Research Center for Hokkaido Region, Memuro, Kasai, Hokkaido 082-0071, Japan. yujioda@affrc.go.jp
Saito
Katsuichi
K
Ohara-Takada
Akiko
A
Mori
Motoyuki
M