Production, purification and characterization of cholesterol oxidase from a newly isolated Streptomyces sp

World J Microbiol Biotechnol. 2013 Nov;29(11):2077-85. doi: 10.1007/s11274-013-1371-8. Epub 2013 May 23.

Abstract

Cholesterol oxidase production (COD) by a new isolate characterized as Streptomyces sp. was studied in different production media and fermentation conditions. Individual supplementation of 1 % maltose, lactose, sucrose, peptone, soybean meal and yeast extract enhanced COD production by 80-110 % in comparison to the basal production medium (2.4 U/ml). Supplementation of 0.05 % cholesterol (inducer) enhanced COD production by 150 %. COD was purified 14.3-fold and its molecular weight was found to be 62 kDa. Vmax (21.93 μM/min mg) and substrate affinity Km (101.3 μM) suggested high affinity of the COD for cholesterol. In presence of Ba(2+) and Hg(2+) the enzyme activity was inhibited while Cu(2+) enhanced the activity nearly threefold. Relative activity of the enzyme was found maximum in triton X-100 whereas sodium dodecyl sulfate inactivated the enzyme. The enzyme activity was also inhibited by the thiol-reducing reagents like Dithiothreitol and β-mercaptoethanol. The COD showed moderate stability towards all organic solvents except acetone, benzene and chloroform. The activity increased in presence of isopropanol and ethanol. The enzyme was most active at pH 7 and 37 °C temperature. This organism is not reported to produce COD.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / chemistry
  • Bacterial Proteins / isolation & purification
  • Bacterial Proteins / metabolism
  • Cholesterol / metabolism*
  • Cholesterol Oxidase / biosynthesis
  • Cholesterol Oxidase / chemistry*
  • Cholesterol Oxidase / isolation & purification
  • Cholesterol Oxidase / metabolism*
  • Chromatography, Affinity
  • Culture Media
  • Electrophoresis, Polyacrylamide Gel
  • Enzyme Stability
  • Fermentation
  • Oxidation-Reduction
  • Phylogeny
  • Soil Microbiology
  • Streptomyces / classification
  • Streptomyces / enzymology*
  • Streptomyces / isolation & purification
  • Substrate Specificity
  • Temperature

Substances

  • Bacterial Proteins
  • Culture Media
  • Cholesterol
  • Cholesterol Oxidase