Directed regulation of whole-cell catalysis for high-quality galactonic acid bio-preparation and characterization by Ca2+

Abstract

For value-added utilization for wood constitute of galactose, which is a kind of hard fermentable lignocellulosic C6 sugar compared with glucose and mannose, a simple and efficient bioprocess for directed regulation of galactonic acid bio-preparation with satisfactory yield and efficiency was described by whole-cell catalysis with native bacterial strain of Gluconobacter oxydans. During the whole-cell catalysis, by employing Ca(OH)2 as neutralizer, 97.7 g of high-quality calcium galactonate was prepared efficiently within 24 h with the productivity of 4.1 g/h, and the serious damage to the product quality caused by the by-product of 2-keto-galactonic acid was completely avoided. As results, based on the consumption of sugar, we successfully achieved 96.9% yield of high purity galactose acid (salts). Moreover, the crystal structure of calcium galactonate was especially prepared and detected by mass spectrometry and 13C NMR in view of relevant studies, as well as standard chemical with high purity for the determination and analysis in chemical and biological fluids. Finally, the biotechnology provides a promising approach for utilization of galactose and promotes application of high purity galactonic acid (salts) in chemical and biological fields.