ENZYMATIC DEGRADATION OF EGG-YOLK CHOLESTEROL

The capacity of four cholesterol oxidases from Nocardia erythropolis ( Ne), Streptomyces species(Ss), Brevibacterium species (Bs) and Pseudom onas fluorescens (Pf) to degrade cholesterol in egg yolk at 4, 25 and 37 degrees C has been determined. The effects of enzyme/substrate conc entration and incubation temperature on the enzymatic activity of thes e cholesterol oxidases have also been investigated. The cholesterol de grading capacity of these enzymes follows the sequence Pf>Ne>Ss>Bs. Up to 93.4% cholesterol was degraded by cholesterol oxidases from P. flu orescens and Streptomyces species after 72 h of incubation at 37 degre es C. At 4 degrees C, P. fluorescens cholesterol oxidase could degrade up to 64.9% cholesterol after 48 h.