title: In vitro transformation of ampicillin to cephalexin by free and immobilized cells of Streptomyces sp.
abstract: In vitro transformation of ampicillin to cephalexin was studied using calcium alginate-immobilized and free Streptomyces sp. strain DRS-1 packed in glass columns. Tris-HCl buffer containing ampicillin was continuously circulated through the columns for four cycles, each cycle (with fresh ampicillin) being continued for 5 h. The pattern of product formation was identical in both cases, i.e. in each cycle, after reaching a certain concentration, its formation did not increase. Product formation was always higher with immobilized cells. Conversion of ampicillin to cephalexin by the strain was affected by cell and substrate concentration.
authors.affiliation: Biochemistry Division, Regional Research Laboratory, Assam, India.
authors.forename: D
authors.initials: D
authors.lastname: Roy
authors.forename: A
authors.initials: A
authors.lastname: Guha
authors.forename: M K
authors.initials: MK
authors.lastname: Roy
authors.forename: A C
authors.initials: AC
authors.lastname: Ghosh
mesh_terms: D000464:Alginates; D000667:Ampicillin / Q000737:chemistry / Q000378:metabolism*; D001711:Biotransformation; D018914:Cells, Immobilized; D002506:Cephalexin / Q000737:chemistry / Q000378:metabolism*; D002511:Cephalosporins / Q000737:chemistry / Q000378:metabolism*; D007218:Industrial Microbiology; D010406:Penicillins / Q000737:chemistry / Q000378:metabolism*; D013302:Streptomyces / Q000254:growth & development* / Q000378:metabolism*
chemical_list: D000464:Alginates; D002511:Cephalosporins; D010406:Penicillins; D000667:Ampicillin; D002506:Cephalexin