Food Science and Biotechnology
→ Food Science and Biotechnology 2020 ; 29(5): 667-674
Properties of recombinant 4-α-glucanotransferase from Bifidobacterium longum subsp. longum JCM 1217 and its application
Da-Woon Jeong1 • Hyun-Mo Jeong1 • Yu-Jeong Shin1 • Seung-Hye Woo1 • Jae-Hoon Shim1
1 Department of Food Science and Nutrition, and The Korean Institute of Nutrition, Hallym University, Chuncheon 24252, Republic of Korea
To determine the physiochemical properties ofthe 4-α-glucanotransferase from Bifidobacterium sp., thebllj_0114 gene encoding 4-α-glucanotransferase was cloned from Bifidobacterium longum subsp. longum JCM1217 and expressed in Escherichia coli. The amino acid sequence alignment indicated that the recombinant protein,named BL-αGTase, belongs to the glycoside hydrolase (GH) family 77. BL-αGTase was purified using nickel- nitrilotriacetic acid affinity chromatography and charac-terized using various substrates. The enzyme catalyzed the disproportionation activity, which transfers a glucosyl unit from oligosaccharides to acceptor molecules, and had the highest activity at 40 °C and pH 6.0. In the presence of 5 mM metal ions, in particular Cu2+, Zn2+, and Fe2+, BL-αGTase activity was reduced. To determine whether BL-αGTase can be used to generate thermoreversible gels, potato starch was treated with BL-αGTase for variousreaction times. The BL-αGTase-treated starches showedsol–gel reversibility and melted at 59.6–75.7 °C.
Bifidobacterium longum · 4-αglucanotransferase · Thermoreversible gel · Transglycosylation
Food Science and Biotechnology 2020 ; 29(5): 667-674