Streptomyces: a superior source for cholesterol oxidase used in serum cholesterol assay.

The present study compared three cholesterol oxidase sources (Nocardia, Streptomyces, and Pseudomonas sps.) for serum cholesterol assay. We found cholesterol oxidase isolated from Streptomyces was superior than those isolated from Nocardia and Pseudomonas sps. Performances of the reagent contained Streptomyces cholesterol oxidase was excellent and comparable to the performances obtained from reagent contained Nocardia cholesterol oxidase. Moreover, the reagent containing Streptomyces cholesterol oxidase had the lowest cost and had the longest shelf-life ($U.S. 0.17/mL, 10 weeks) compared to the reagent contained Nocardia ($U.S. 0.50/mL, 8 weeks) or Pseudomonas ($U.S. 0.20/mL, 6 weeks) cholesterol oxidase.