Thermophilic fungus Thermomyces lanuginosus CBS 395.62/b strain is able to grow and synthesise extracellular alpha-galactosidase in media containing galactomannan such as locust bean gum (LBG) or guar gum (GG). Production of extracellular alpha-galactosidase was enhanced from 1.2 U/mL to 4-6 U/mL meaning about 3-5 times increase by optimisation of medium composition. This enzyme was purified to homogeneity by partial precipitation with 2-propanol and different liquid chromatographical steps. The developed purification protocol yielded 22% of enzyme activity with 900 purified fold. Molecular mass of the purified alpha-galactosidase enzyme was estimated to be 53 kDa. Maximal catalytic activity of the enzyme was obtained in the acidic pH range between pH 4.6 and 4.8 and in the temperature range 60-66 degrees C. More than 95% of enzyme activity was remaining after 1-day incubation at 70 degrees C and on pH in the range from 4.0 to 7.0. The enzyme activity was significantly stimulated by Mg2+, Mn2+ and K+ ions, while considerably inhibited by the presence of Ca2+ Ag+ and Hg2+. (c) 2009 Elsevier Inc. All rights reserved.