Galactosidases are industrially important enzymes that hydrolyze galactosidic bonds in carbohydrates. Identifying new galactosidases with distinct functional characteristics is of paramount importance. In this study, we report the finding of a novel β-galactosidase PoβGal35A from the fungus Penicillium oxalicum. PoβGal35A belongs to the glycoside hydrolase family 35 (GH35), functions optimally at 70 °C and pH 5.0, and exhibits a specific high activity (191 ± 6.2 U/mg) towards pNPβgal. Ca2+, Fe3+and Ba2+ ions enhance the activity of the enzyme, whereas Cu2+ and Hg2+ significantly reduce it. This enzyme releases galactose from β-1,3-galactan, β-1,4-galactan, β-1,6-galactan, as well as arabinogalactan from larchwood (LWAG). In addition, PoβGal35A acts synergistically with arabinosidase to degrade LWAG. These results suggest that PoβGal35A is a high activity exo-β-1,3/4/6-galactanase that can be used to establish glycan blocks in glycoconjugates, and thus provides a new tool for biotechnological applications.
Keywords: GH35; Galactan; Larchwood arabinogalactan; Penicillium oxalicum; β-galactosidase.
© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.