Abstract: The present invention relates to novel .alpha.-glucosidase being excellent in stability to heat and pH, and hydrolyzing .alpha.-glucoside linkages to form .alpha.-D-glucose, acting on maltose, maltotriose, maltotetraose, PNPG, PNPG2, isomaltose and sucrose, but hardly acting on maltooligosaccharides with a degree of polymerization of maltopentaoside or more, and completely not acting on soluble starch, as well as to a process for producing the same by use of a strain belonging to the genus Bacillus capable of producing .alpha.-glucosidase. .alpha.-Glucosidase which is useful as a coupling enzyme for quantification such as measurement of .alpha.-amylase activity, or in formation of monosaccharides such as glucose and fructose etc., from oligosaccharides, and enzymatic synthesis of heterooligosaccharides, can be produced easily and inexpensively.

Abstract: The invention relates to a novel pyranose oxidase, a pyranose oxidase gene, and a recombinant DNA, as well as a process for producing the pyranose oxidase by use of a microorganism carrying said recombinant DNA. The process of the invention enables efficient production of the novel pyranose oxidase.