Immunochemical Identification of a New Thermostable β-Galactosidase from a Bacillus Species

Abstract

A recently found Bacillus strain produces a new thermostable β-galactosidase (1). The enzyme was purified by sodium dodecyl sulfate (SDS) Polyacrylamide gel electrophoresis and monospecific antiserum against it was produced in rabbits. Crude extracts from more than 30 strains belonging to different thermophilic Bacillus species were analyzed for content of β-galactosidase. The moleuclar weight of these β-galactosidases were determined after SDS Polyacrylamide gel electrophoresis and their identity to the new enzyme was analyzed with the monospecific antiserum. Four of these strains contained this new enzyme and the moleuclar weight of the active monomer was determined as 120,000. Three other classes of thermostable β-galactosidases were found. They have molecular weights of 70,000, 150,000 and 200,000 and show no immunological identity to the new enzyme.