PURIFICATION AND SOME PROPERTIES OF ALPHA-AMYLASE FROM BACILLUS-SUBTILIS X-23 THAT GLUCOSYLATES PHENOLIC-COMPOUNDS SUCH AS HYDROQUINONE

Six hundred strains of soil microorganisms were screened for the produ ction of hydroquinone glucosylating enzyme (HGE). One of these strains , Bacillus subtilis strain X-23, produced an enzyme that glucosylated hydroquinone in the culture filtrate. The HGE was successively purifie d by ammonium sulfate fractionation, and Q-Sepharose, Phenyl-Toyopearl , and Superose 12 column chromatographies. The molecular weight was es timated as 65 kDa by SDS-polyacrylamide gel electrophoresis, and 54 kD a by gel filtration. Based on an analysis of the hydrolytic products f rom soluble starch, HGE was considered to be a kind of alpha-amylase. The structure of the hydroquinone glucoside produced by HGE was identi fied as 4-hydroxyphenyl-O-alpha-D-glucopyranoside by alpha- and beta-g lucosidase treatments, and H-1-NMR and C-13-NMR.