We found a match
Your institution may have access to this item. Find your institution then sign in to continue.
- Title
Stereo-selective conversion of mandelonitrile to ( R)-(−)-mandelic acid using immobilized cells of recombinant Escherichia coli.
- Authors
Pawar, Sandip; Meena, Vachan; Kaushik, Shubhangi; Kamble, Ashwini; Kumar, Sandeep; Chisti, Yusuf; Banerjee, U.
- Abstract
Immobilized cells of a recombinant Escherichia coli expressing nitrilase from Pseudomonas putida were used to catalyze the hydrolysis of mandelonitrile (2-hydroxy-2-phenylacetonitrile) to ( R)-(−)-mandelic acid. The cells had been immobilized by entrapment in an alginate matrix. Conditions for the hydrolysis reaction were optimized in shake flasks and in a packed bed reactor. In shake flasks the best conditions for the reaction were a temperature of 40 °C, pH 8, biocatalyst bead diameter of 4.3 mm, sodium alginate concentration in the gel matrix of 2 % (w/v, g/100 mL), a cell dry mass concentration in the bead matrix of 20 mg/mL, an initial substrate concentration of 50 mM and a reaction time of 60 min. Under these conditions, the conversion of mandelonitrile was nearly 95 %. In the packed bed reactor, a feed flow rate of 20 mL/h at a substrate concentration of 200 mM proved to be the best at 40 °C, pH 8, using 4.3 mm beads (2 % w/v sodium alginate in the gel matrix, 20 mg dry cell concentration per mL of gel matrix). This feed flow rate corresponded to a residence time of 0.975 h in the packed bed.
- Publication
3 Biotech, 2012, Vol 2, Issue 4, p319
- ISSN
2190-572X
- Publication type
Article
- DOI
10.1007/s13205-012-0058-4