DEXTRAN-DEGRADING ENZYMES FROM MOLDS

Abstract

Enzymes capable of degrading dextran, the polymer of glucose produced from sucrose by the action of Leuconostoc mesenteroides and related organisms, are potentially valuable for fundamental research as well as for practical applica-tion. Although the a-i,6-glucopyranosidic linkage is present to the extent of 95 per cent or more in some easily obtainable dextrans, the only other known occurrence of this linkage is the 5 to 10 per cent found in starch, glycogen, and similar polysaccharides. Thus, as has been pointed out previously by Jeanes et al. (1948), dextran provides a unique source of simpler carbohydrates containig the a-1,6-glu-cosidic linkage obtainable through enzymic degradation. Enzymes produced by organisms grown on dextran and capable of cleaving the 1,6 linkage may be useful in studies concerning starch structure. And lastly, as has been indicated already by Ingelman (1948) and by Whiteside-Carlson and Carlson (1952), 'ther types of dextranases offer a means for degrading dextran to molecular size range suitable for use as synthetic blood volume expanders.