PURIFICATION AND CHARACTERIZATION OF AN ENDO ALPHA-1,3-D-MANNANASE FROM FLAVOBACTERIUM SP AS-9

A novel mannanase that has a strict specificity for the alpha-1,3-mann osidic linkage has been isolated and characterized, The enzyme was pur ified to homogeneity from the cultural supernatant of a soil bacterium , Flavobacterium sp. AS-9 isolated by enrichment culture on Auriculari a mannan of which the structure was an alpha-1,3-linked D-mannan main chain branched with short segments of xylose or glucuronic acid. Purif ied mannanase was optimally active between pH 6 and 8, The apparent mo lecular mass of the enzyme was 94 kDa by SDS gel electrophoresis under reducing conditions and 100 kDa by gel filtration HPLC, The enzyme on ly hydrolyzed alpha-1,3-D-mannan with endo-type action to produce alph a-1,3-mannooligosaccharides of various sizes, The smallest product was alpha-1,3-mannobiose.