Biotechnology Letters, Vol.37, No.7, 1431-1437, 2015
Biotransformation of sucrose into hexyl-alpha-d-glucopyranoside and -polyglucosides by whole cells of Microbacterium paraoxydans
To determine the transglycosylation activity of cell-bound enzymes from Microbacterium paraoxydans to catalyze the synthesis of hexyl-alpha-d-glucoside (HG) and -polyglucosides using sucrose as a glycosyl donor. Maximum HG yield (14.8 %) was achieved at 0.96 water activity in 12 h with sucrose at 0.5 M with lyophilized cells (equivalent to 8 IU alpha-glucosidase activity). The synthesized alkyl-glucosides and-polyglucosides were characterized by ESI-MS. Structural elucidation of the main product (purified by solid phase chromatography) was done by HSQC (2D NMR) which was confirmed as 1-hexyl-alpha-d-glucopyranoside. The synthesis was scaled up in a fed-batch reactor, with continuous feeding of whole cells every 6 h and a total yield of similar to 44 % was obtained for hexyl-glucoside and -polyglucosides under the optimized conditions. Synthesis of HG, hexyl di- and tri-glucosides has been achieved using a novel method.
Keywords:Alkyl glucosides;A-glucosidase;Hexyl-alpha-D-glucopyranoside;Hexyl-polyglucosides;Microbacterium paraoxydans;Transglycosylation;Whole-cell catalysis