IDENTIFICATION OF A NEW TYPE OF AMYLASE AND MUTAGENESIS OF STRAIN ZX99 SECRETING THE ENZYME FOR PRODUCTION OF ISOMALTOOLIGOSACCHARIDE / 微生物学通报

ABSTRACT

This paper reported a new type of amylase (neoamylase) secreted by a Bacillus strain ZX99. The enzyme was a kind of ectoenzyme that could catalyze starch into isomalto-oligosaccharide effectively, but could not act on pullulan as substrate. The strain Bacillus ZX99 was mutated by ultraviolet ray and a mutant strain BS3.232 was screened. The activity of the neoamylase produced from BS3.232 increased by 60% over that from ZX99 under the same conditions. The results of thin-layer chromatography of products from starch and pullulan catalyzed by the enzyme demonstrated that the enzyme was different from neopullulanase and can be used to produce isomaltooligosaccharide from starch, including isomaltose, panose, isomaltotriose, isomaltotetose.