title: Effects of ascorbic acid on α-l-arabinofuranosidase and α-l-arabinopyranosidase activities fromBifidobacterium longumRD47 and its application to whole cell bioconversion of ginsenoside.
abstract: Bifidobacterium longumRD47 was cultured in 24 kinds of modified MRS broths containing various ingredients to select the most promising source that induces microbial enzymes. Among the various ingredients, ascorbic acid significantly enhanced α-l-arabinofuranosidase and α-l-arabinopyranosidase activities inBifidobacterium longumRD47. Addition of 2 % ascorbic acid (w/v) to MRS showed the maximum enzyme activities. Both whole cell and disrupted cell homogenates showed efficient ρ-nitrophenyl-β-d-glucopyranoside and ρ-nitrophenyl-β-d-glucofuranoside hydrolysis activities. The initially enhanced α-l-arabinopyranosidase and α-l-arabinofuranosidase activities by ascorbic acid were maintained over the cell disruption process. The optimal pH of α-l-arabinofuranosidase and α-l-arabinopyranosidase was 5.0 and 7.0, respectively. Both enzymes showed the maximum activities at 40.0 °C. Under the controlled condition usingBifidobacterium longumRD47, ginsenoside Rb2, and Rc were converted to ginsenoside Rd.
authors.affiliation: Department of Food and Nutrition, Research Institute of Human Ecology, Seoul National University, 222 Dong 524Ho, Seoul, 151-742 Republic of Korea ; Laboratory of Renewable Resources Engineering, Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, IN 47907-2022 USA.
authors.forename: Seockmo
authors.initials: S
authors.lastname: Ku
authors.affiliation: Department of Food and Nutrition, Research Institute of Human Ecology, Seoul National University, 222 Dong 524Ho, Seoul, 151-742 Republic of Korea.
authors.forename: Hyun Ju
authors.initials: HJ
authors.lastname: You
authors.affiliation: Department of Hotel Culinary Arts, Yeonsung University, Anyang, 430-749 Republic of Korea.
authors.forename: Myeong Soo
authors.initials: MS
authors.lastname: Park
authors.affiliation: Department of Food and Nutrition, Research Institute of Human Ecology, Seoul National University, 222 Dong 524Ho, Seoul, 151-742 Republic of Korea ; Research Center, BIFIDO Co. Ltd., Hongcheon, 250-804 Republic of Korea.
authors.forename: Geun Eog
authors.initials: GE
authors.lastname: Ji
keywords: Ascorbic acid; Bifidobacterium; Bioconversion; Ginsenosides; α-l-Arabinofuranosidase; α-l-Arabinopyranosidase