Improvement of selectivity in 3-ketocellobiose production from cellobiose by Agrobacterium tumefaciens

Abstract

Agrobacterium tumefaciens cells were treated by three different methods, ethylenediaminetetraacetic acid- (EDTA) treatment, cold osmotic shock-treatment and toluene-treatment, and cellobiose was transformed to 3-ketocellobiose using the cells as catalyst. The EDTA-treatment was the best among the methods for improving the selectivity in the transformation. The effect of the EDTA concentration during the treatment at 30°C on the selectivity was examined, and 10 mmol/l or lower EDTA was sufficient for the improvement. The cells were treated at different temperatures and at 5 mmol/l EDTA, and the cells treated at 45°C exhibited the highest selectivity in the transformation.