title: Improvement in the resting-cell bioconversion of penicillin G to deacetoxycephalosporin G by addition of catalase.
abstract: OBJECTIVE
  To improve the resting cell bioconversion of penicillin G to deacetoxycephalosporin G (DAOG) by elimination of an oxidizing intermediate which inactivates the enzyme during the reaction.
  
  
  RESULTS
  Resting cells of Streptomyces clavuligerus strain NP1 were incubated with penicillin G, required co-factors and decane in the presence of catalase or superoxide dismutase, and production of DAOG was measured. Catalase stimulated the bioconversion but superoxide dismutase did not.
  
  
  CONCLUSIONS
  Production of hydrogen peroxide during the ring expansion reaction is at least partially responsible for enzyme inactivation.
  
  
  CONCLUSIONS
  Catalase addition improves the bioconversion and will contribute to the eventual replacement of the current multi-step, expensive and environmentally-unfriendly chemical ring expansion by a biological route.
authors.affiliation: Biology Department, Massachusetts Institute of Technology, Cambridge, MA, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Gao
authors.forename: A L
authors.initials: AL
authors.lastname: Demain
mesh_terms: D000473:Alkanes / Q000737:chemistry; D001711:Biotransformation; D002374:Catalase / Q000378:metabolism*; D002511:Cephalosporins / Q000096:biosynthesis*; D010400:Penicillin G / Q000378:metabolism*; D010406:Penicillins / Q000378:metabolism*; D013302:Streptomyces / Q000201:enzymology / Q000378:metabolism*
chemical_list: D000473:Alkanes; D002511:Cephalosporins; D010406:Penicillins; C405006:deacetoxycephalosporin G; D002374:Catalase; D010400:Penicillin G