ISOLATION OF CUTICLE-DEGRADING BACILLUS-C EREUS NS-11 AND PROPERTIES OF THE ENZYME PRODUCED BY THE BACTERIUM

A wool cuticle-degrading bacterium was isolated from soil and identifi ed as Bacillus cereus (strain NS-11). The cuticle-degrading enzyme pro duced by the bacterium had high activity against wool keratin rather t han casein. The optimum pH of the enzyme was 8, and it was stable betw een pH 5 and 9. The enzyme easily hydrolyzed denatured keratin, such a s that which was chemically modified, but hardly hydrolyzed native ker atin. Amorphous wool keratin was hydrolyzed by the enzyme more quickly with the assistance of hydrogen peroxide, whereas hydrogen peroxide w as of little assistance in the hydrolysis of pulverized wool fibers. H owever, in the presence of hydrogen peroxide the enzyme modified the c uticle components preferentially without damaging the inner components of the wool fibers. The enzyme produced by the isolated strain is thu s expected to be effectual in the shrink proofing of wool without decr easing its tensile-strength or abrasion-resistance.