A novel low temperature active maltooligosaccharides-forming amylase from Bacillus koreensis HL12 as biocatalyst for maltooligosaccharide production.
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ABSTRACT: Maltooligosaccharide-forming amylases (MFAses) are promising enzymes for a variety of industrial applications. In this study, a maltooligosaccharide-forming amylase (BkAmy) isolated from Bacillus koreensis HL12 was first heterologous expressed and characterized. According to structural-sequence alignment, BkAmy contained seven conserved regions which are the signature of a novel GH13 subfamily. The gene was expressed in Pichia pastoris KM71 as an extracellular protein with a volumetric activity of 3.38 U/mL culture medium after 72 h induction by 3% (w/v) of methanol. The recombinant BkAmy migrated as a single protein band with an expected size approximately of 55 kDa. BkAmy exhibited the highest catalytic activity on soluble starch with a specific activity of 42.2 U/mg at 40 °C, pH 7.0. The enzyme exhibited 65% relative activity at 30 °C, indicating its advantage on application at moderate reaction temperature desirable for energy saving and reduction of side unwanted reactions. The enzyme exhibited a specific cleavage pattern by releasing maltose (G2), maltotriose (G3) and maltotetraose (G4) from cassava starch with the highest yield of 363 mg/g substrate equivalent to 36% conversion using 40 U/g substrate at 60 min. The work demonstrates the potential of this enzyme on maltooligosaccharide production from starch to create high value-added products in starch processing industries.Supplementary information
The online version contains supplementary material available at 10.1007/s13205-022-03188-1.
SUBMITTER: Lekakarn H
PROVIDER: S-EPMC9124740 | biostudies-literature | 2022 Jun
REPOSITORIES: biostudies-literature
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