TY - JOUR
T1 - Optimization of lactulose synthesis from whey lactose by immobilized β-galactosidase and glucose isomerase
AU - Song, Yoon Seok
AU - Lee, Hee Uk
AU - Park, Chulhwan
AU - Kim, Seung Wook
N1 - Funding Information:
This study was supported by Technology Development Program (309016-5) for Agriculture and Forestry, Ministry for Food, Agriculture, Forestry and Fisheries, Republic of Korea and the Advanced Biomass R&D Center (ABC-2010-0029799) of Korea Grant funded by the Ministry of Education, Science and Technology.
PY - 2013
Y1 - 2013
N2 - In the present study, commercially available whey was used as a lactose source, and immobilized β-galactosidase and glucose isomerase were used to synthesize lactulose from whey lactose in the absence of fructose. Optimal reaction conditions, such as lactose concentration, temperature, ionic strength of the buffer, and ratio of immobilized enzymes, were determined to improve lactulose synthesis using immobilized enzymes. Lactulose synthesis using immobilized enzymes improved markedly after optimizing the reaction conditions. When the lactulose synthesis was carried out at 53.5 °C using 20% (w/v) whey lactose, 12 U/ml of immobilized β-galactosidase and 60 U/ml of immobilized glucose isomerase in 100 mM sodium phosphate buffer at pH 7.5, the lactulose concentration and specific productivity were 7.68 g/l and 0.32 mg/U h, respectively. Additionally, when the immobilized enzymes were reused for lactulose synthesis, their catalytic activity was 57.1% after 7 repeated uses.
AB - In the present study, commercially available whey was used as a lactose source, and immobilized β-galactosidase and glucose isomerase were used to synthesize lactulose from whey lactose in the absence of fructose. Optimal reaction conditions, such as lactose concentration, temperature, ionic strength of the buffer, and ratio of immobilized enzymes, were determined to improve lactulose synthesis using immobilized enzymes. Lactulose synthesis using immobilized enzymes improved markedly after optimizing the reaction conditions. When the lactulose synthesis was carried out at 53.5 °C using 20% (w/v) whey lactose, 12 U/ml of immobilized β-galactosidase and 60 U/ml of immobilized glucose isomerase in 100 mM sodium phosphate buffer at pH 7.5, the lactulose concentration and specific productivity were 7.68 g/l and 0.32 mg/U h, respectively. Additionally, when the immobilized enzymes were reused for lactulose synthesis, their catalytic activity was 57.1% after 7 repeated uses.
KW - Glucose isomerase
KW - Lactose
KW - Lactulose
KW - Whey
KW - β-Galactosidase
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U2 - 10.1016/j.carres.2013.01.002
DO - 10.1016/j.carres.2013.01.002
M3 - Article
C2 - 23353997
AN - SCOPUS:84872682822
VL - 369
SP - 1
EP - 5
JO - Carbohydrate Research
JF - Carbohydrate Research
SN - 0008-6215
ER -