title: Synthesis and characterisation of galactosyl glycerol by β-galactosidase catalysed reverse hydrolysis of galactose and glycerol.
abstract: A study of an enzymatic method for the production of galactosylglycerol is described. The effects of enzyme sources, enzyme amount, reaction temperature, reaction time, substrate ratio of glycerol to galactose, buffer content and pH on galactosylglycerol yield (mg/ml) were investigated. Under the optimum reaction conditions of β-galactosidases from Kluyveromyces lactis 240 U/ml, temperature 40 °C, time 24 h, buffer amount 60% (percent volume of buffer to that of substrates, pH 6.5), and the substrate molar ratio of 10 (glycerol16 mmol:galactose 1.6 mmol), the yield of galactosylglycerol was up to 116.47 mg/ml (galactose conversion 55.88%). The product was purified by activated charcoal and Sephadex G-15 column chromatography, up to 96%. The purified galactosylglycerol was fully characterised by MS and NMR, and identified as a mixture of (2R)- and (2S)- 3-O-β-D-galactopyranosyl-glycerol.
authors.affiliation: College of Food Science and Technology, Nanjing Agricultural University, Nanjing 210095, PR China.
authors.forename: Wei
authors.initials: W
authors.lastname: Wei
authors.forename: Danping
authors.initials: D
authors.lastname: Qi
authors.forename: Hai-zhen
authors.initials: HZ
authors.lastname: Zhao
authors.forename: Zhao-xin
authors.initials: ZX
authors.lastname: Lu
authors.forename: Fengxia
authors.initials: F
authors.lastname: Lv
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Bie
mesh_terms: D055162:Biocatalysis; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism; D005690:Galactose / Q000737:chemistry* / Q000378:metabolism; D005990:Glycerol / Q000737:chemistry* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007700:Kinetics; D007716:Kluyveromyces / Q000201:enzymology*; D001616:beta-Galactosidase / Q000737:chemistry* / Q000378:metabolism
chemical_list: D005656:Fungal Proteins; D001616:beta-Galactosidase; D005990:Glycerol; D005690:Galactose
keywords: Characterisation; Galactosylglycerol; Reverse hydrolysis; β-Galactosidase