Abstract
Experiments on the decomposition of riboflavin glucosyl compounds were carried out with cell-free extracts of Leuconostoc mesenteroides NRRL B-1299 (=IAM 1151) grown on sucrose. Riboflavin glucoside (B2-gl), riboflavin isomaltoside (B2-gl-gl), riboflavin isomaltotrioside (B2-gl-gl-gl) and higher members of riboflavin oligoglucosyl compound (B2-(gl)n) were principally decomposed by the action of intracellular extract, according to the following routes:
B2-gl→B2
B2-gl-gl→B2-gl→B2
B2-gl-gl-gl→B2-gl-gl→B2
B2-(gl)n→B2-(gl)n-1→
The activity revealing decomposition of riboflavin glucosyl compounds and the activity revealing formation of riboflavin glucosyl compounds were separated from each other by the ammonium sulfate precipitation method. It was observed that an oligo-α-1, 6-glucosidase-like enzyme existed in the ammonium sulfate fraction having the decomposing activity of riboflavin glucosyl compounds. Oligo-α-1, 6-glucosidase-like enzyme which was prepared from dextran-synthesizing cells of Leuc. mesenteroides readily hydrolyzed isomaltose and isomaltotriose to glucose, but scarcely maltose, sucrose, dextran, amylose, amylopectin or glycogen.
