title: Biodegradation of cytotoxic 7-Ketocholesterol by Pseudomonas aeruginosa PseA.
abstract: The present study aims to degrade 7-Ketocholesterol (7KC), a major oxysterol implicated in many age-related disorders, through microbial means and find candidate enzymes involved for further application in food systems and as a therapeutic. During initial screening of previously isolated bacteria from our laboratory, Pseudomonas aeruginosa PseA was found to be a potential degrader strain using 7KC as a sole carbon source. Under optimized conditions, it is able to degrade 88% of an initial concentration of 1000ppm (1g/l) 7KC. Preliminary in vitro studies with extra-cellular extract has shown degradation of the compound, thus reinforcing the occurrence of suitable enzymatic systems involved in the process. We have been able to identify cholesterol oxidase as one such potential enzyme. Some intermediate products of degradation have also been identified. This is the first detailed report of 7KC degradation by a P. aeruginosa strain.
authors.affiliation: Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India.
authors.forename: Shubhrima
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Enzyme and Microbial Biochemistry Laboratory, Department of Chemistry, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India. Electronic address: skkhare@chemistry.iitd.ac.in.
authors.forename: S K
authors.initials: SK
authors.lastname: Khare
mesh_terms: D001673:Biodegradation, Environmental; D002789:Cholesterol Oxidase / Q000096:biosynthesis; D007653:Ketocholesterols / Q000378:metabolism*; D011550:Pseudomonas aeruginosa / Q000378:metabolism*
chemical_list: D007653:Ketocholesterols; D002789:Cholesterol Oxidase; C003001:7-ketocholesterol
keywords: 7-Ketocholesterol; Biodegradation; Cytotoxic; Enzyme; Pseudomonas