title: Cholesterol oxidase production from entrapped cells of Streptomyces sp.
abstract: Production of cholesterol oxidase (COD) under batch conditions through Ca-alginate immobilized cells of Streptomyces sp. was investigated. The process was studied for optimal immobilization conditions, beads operational stability and comparisons were made with the COD production via free cells. Influence of Na-alginate concentration (1-5 g L(-1) ) and initial biomass loading on enzyme production were studied. Effects of initial pH of the production medium, temperature, shaker speed, as well as reuse of beads on the COD production were also investigated. It was observed that COD production with immobilized cells (5.6 U ml(-1) ) was higher in comparison to free cells (4.5 U ml(-1) ) under optimized conditions. The maximum COD production by free cells was observed with initial pH 7.0, rpm 200 after 96 h of incubation while immobilized cells sustain a broad pH range 6.0-9.0, rpm 300 for maximum production after 72 h. The immobilized and free cells produced maximum COD in the culture incubated at 37 and 30 °C, respectively. Other parameters bead size and Na-alginate concentration found to be optimum with 1.5 mm and 4% w/v, respectively. Scanning electron microscope study of the immobilized cells indicated that the cells in Ca-alginate beads remained in normal shape with no alterations in the morphology.
authors.affiliation: Microbiology Division, CSIR-Central Drug Research Institute, Lucknow, India.
authors.forename: Ram
authors.initials: R
authors.lastname: Niwas
authors.forename: Vineeta
authors.initials: V
authors.lastname: Singh
authors.forename: Rajbir
authors.initials: R
authors.lastname: Singh
authors.forename: Garima
authors.initials: G
authors.lastname: Pant
authors.forename: Kalyan
authors.initials: K
authors.lastname: Mitra
authors.forename: Chandra Kant Mani
authors.initials: CK
authors.lastname: Tripathi
mesh_terms: D000464:Alginates; D018914:Cells, Immobilized / Q000378:metabolism*; D002789:Cholesterol Oxidase / Q000378:metabolism*; D003470:Culture Media / Q000737:chemistry; D020723:Glucuronic Acid; D006603:Hexuronic Acids; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D013302:Streptomyces / Q000378:metabolism* / Q000648:ultrastructure; D013696:Temperature
chemical_list: D000464:Alginates; D003470:Culture Media; D006603:Hexuronic Acids; D020723:Glucuronic Acid; D002789:Cholesterol Oxidase
keywords: Cholesterol oxidase; Immobilization; Scanning electron microscopy; Sodium alginate; Streptomyces sp.