The polysaccharides of galactose present in the pectin of the plant cell wall are degraded by endo-beta-1,4-galactanases. The filamentous fungus Penicillium purpurogenum, which grows on a number of natural carbon sources, among them sugar beet pulp which contains pectin, has a gene (ppgal1) coding an endo-beta-1,4-galactanase (PpGAL1). This enzyme was expressed heterologously in Pichia pastoris. It has a molecular mass of 38 kDa, a pH optimum of 4-4.5, and an optimal temperature of 60 A degrees C. It is 100 % stable for up to 24 h at pH 4-4.5 and 40 A degrees C. These stability properties, which exceed those from other endo-beta-1,4-galactanases reported to date, make it particularly suitable for industrial processes requiring acidic conditions and temperatures up to 40 A degrees C. PpGAL1 is, therefore, a potentially effective tool in the food industry and in other biotechnological applications.