Enzymatic Conversion of D-Glucose to D-Fructose Part I. Identification of Active Bacterial Strain and Confirmation of D-Fructose Formation

Enzymes which catalyze the interconversion of free aldopentose and ketopentose have been demonstrated in several bacterial strains. Concerning the conversion of free hexoses, however, the cases reported are few. Palleroni and Doudoroff1) described mannose isomerase in Pseudomonas saccharophila, which converted mannose to fructose. Marshall and Kooi2) then reported the ability of Pseudomonas hydrophila to isomerise D-glucose to D-fructose. Recently, Bartfay3) suggested the presence of glucose isomerase in barley malt. This report presents the results of investigation on a bacterial strain which also has glucose isomerization activity. METHODS Isolation of Strain. Humus collected from the outskirts of Tokyo and other places were dispersed in sterile water and one drop each of the supernatant was inoculated into 10ml portions of liquid medium in test tubes, which contained D-xylose as sole carbon source (Table I). These tubes were maintained at 30°C for 2~3 days