Some enzymatic properties of cholesterol oxidase produced by Brevibacterium sp

Abstract

In this study we determined some properties of the cholesterol oxidase from a Brevibacterium strain isolated from buffalos milk and identified the cholesterol degradation products by the bacterial cell. A small fraction of the enzyme synthesized by cells cultured in liquid medium for 7days was released into the medium whereas a larger fraction remained bound to the cell membrane. The extraction of this fraction was efficiently accomplished in 1 mM phosphate buffer, pH 7.0, containing 0.7% Triton X-100. The enzyme stability under freezing and at 45 o C was improved by addition of 20% glycerol. The optimum temperature and pH for the enzyme activity were 53°C and 7.5, respectively. The only steroidal product from cholesterol oxidation by the microbial cell and by the crude extract of the membrane-bound enzyme was 4-colesten-3-one. Chromatographic analysis showed that minor no steroidal compounds as well as 4-colesten-3-one found in the reaction media arose during fermentation process and were extracted together with the enzyme in the buffer solution. Cholesterol oxidation by the membrane-bound enzyme was a first order reaction type.

Optimization of cholesterol oxidase production and 16S rRNA partial sequence of Bacillus cereus strain KAVK4 isolated from butter

“…Some microorganisms were effectively produced cholesterol oxidase based on the temperature. The optimum temperature for this enzyme production Rhodoccococus equi was at 47°C and Corynebacterium cholesterolicum production of this enzyme was at 40°C respectively (Salva et al, 1999). Streptomyces fradiae and Brevibacterium sp.…”

Recent advances in cholesterol biosensor

“…and have shown that detergent is required for the extraction of ChOx and the activity depends on the concentration of detergent (Triton X-100). They have brought out that enzyme loses its complete activity at 0% concentration of detergent (Salva et al, 1999). Gadda et al have characterized cholesterol oxidase and have studied the effect of detergent, alcohol and phosphate upon ChOx activity.…”

Medium optimization by orthogonal array and response surface methodology for cholesterol oxidase production by Streptomyces lavendulae NCIM 2499

“…Cholesterol oxidase (COD; EC 1.1.3.6), is a bifunctional enzyme, which catalyzes the oxidation of cholesterol (5-cholesten-3-ol) to the temporary intermediate 5-cholesten-3-one with the reduction of molecular oxygen to hydrogen peroxide, and the isomerization of the Δ 5 -bond to Δ 4 -bond (4-cholesten-3-one) (Salva et al, 1999;Yamashita et al, 1998). It was observed that there is an increase in cardiovascular diseases and cardiac arrest is a major cause of death all over the world (Davisa et al, 1995).…”