The enantioselective hydrolysis of different (RS)-1,2-O-isopropylidene glycerol esters has been achieved with whole cells of Bacillus coagulans NCIMB 9365 furnishing the (S)-alcohol as the major enantiomer. The reaction is catalysed by a thermostable cell-bound carboxylesterase and improvement of the enantioselectivity has been achieved by heat treatment of the whole cells, which causes the knock-outs a non-enantioselective competing enzyme. Thermally-treated cells hydrolysed (RS)-1,2-O-isopropylidene glycerol esters with high enantioselectivity, the highest enantiomeric ratio (80-100) being observed for the benzoate. The biocatalyst displayed good stability and could be re-used after filtration for 12 cycles before showing significant loss of activity; repeated biotransformation batches allowed the recovery of 9.55 g/L of enantiomerically pure (S)-isopropylideneglycerol benzoate starting from 24.0 g/L of the racemic mixture. (C) 2005 Elsevier Ltd. All rights reserved.
Enhanced enantioselectivity of Bacillus coagulans in the hydrolysis of 1,2-O-isopropylidene glycerol esters by thermal knock-out of undesired enzymes / D. Romano, F. Falcioni, D. Mora, F. Molinari, A. Buthe, M. Ansorge Schumacher. - In: TETRAHEDRON-ASYMMETRY. - ISSN 0957-4166. - 16:4(2005), pp. 841-845. [10.1016/j.tetasy.2004.12.021]
Enhanced enantioselectivity of Bacillus coagulans in the hydrolysis of 1,2-O-isopropylidene glycerol esters by thermal knock-out of undesired enzymes
D. Romano;D. Mora;F. Molinari;
2005
Abstract
The enantioselective hydrolysis of different (RS)-1,2-O-isopropylidene glycerol esters has been achieved with whole cells of Bacillus coagulans NCIMB 9365 furnishing the (S)-alcohol as the major enantiomer. The reaction is catalysed by a thermostable cell-bound carboxylesterase and improvement of the enantioselectivity has been achieved by heat treatment of the whole cells, which causes the knock-outs a non-enantioselective competing enzyme. Thermally-treated cells hydrolysed (RS)-1,2-O-isopropylidene glycerol esters with high enantioselectivity, the highest enantiomeric ratio (80-100) being observed for the benzoate. The biocatalyst displayed good stability and could be re-used after filtration for 12 cycles before showing significant loss of activity; repeated biotransformation batches allowed the recovery of 9.55 g/L of enantiomerically pure (S)-isopropylideneglycerol benzoate starting from 24.0 g/L of the racemic mixture. (C) 2005 Elsevier Ltd. All rights reserved.Pubblicazioni consigliate
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