PURIFICATION AND PROPERTIES OF BETA-FRUCTOFURANOSIDASE FROM AUREOBASIDIUM SP ATCC-20524

Purification and properties of two beta-fructofuranosidases, which produce 1-kestose (1F-beta-fructofuranosyl-sucrose) from sucrose, from Aureobasidium sp. ATCC 20524 are reported. The enzymes were purified to homogeneity by fractionations involving ethanol, calcium acetate and ammonium sulfate and DEAE-Cellulofine and Sephadex G-200 chromatography. Molecular weights of the enzymes were estimated to be about 318000 (P-1) and 346000 (P-2) daltons by gel filtration. The enzymes were glycoproteins that contained about 30% (w/v) (P-1) and 53% (w/v) (P-2) carbohydrate. The optimum pH for the enzymatic reactions were 4.5-5.5 (P-1) and 4.5-6 (P-2). The enzymes were stable over a wide pH range (4-9). The optimum reaction temperatures for both enzymes were 50-55-degrees-C and they retained more than 94% (P-1) and 98% (P-2) activities at 50-degrees-C after 15 min. The K(m) values for sucrose were 0.47 M (P-1) and 0.65 M (P-2). The enzymes were inhibited by mercury, copper and lead ions as well as p-chloromercuribenzoate.