Characterization of a thermostable endo-β-1,4-D-galactanase from the hyperthermophile Thermotoga maritima

Abstract

A putative endo-β-1,4-D-galactanase gene of Thermotoga maritima was cloned and overexpressed in Escherichia coli. The recombinant enzyme hydrolyzed pectic galactans and produced D-galactose, β-1,4-D-galactobiose, β-1,4-D-galactotriose, and β-1,4-D-galactotetraose. The enzyme displayed optimum activity at 90°C and pH 7.0. It was slowly inactivated above pH 8.0 and below pH 5.0 and stable at temperatures up to 80°C.