title: Detection of a cephalosporin C acetyl esterase in the carbamate cephalosporin antibiotic-producing culture, Streptomyces clavuligerus.
abstract: The possible role of a cephalosporin C acetyl esterase in the formation of the beta-lactam antibiotic A16886A, 7-(5-amino-5-carboxyvaleramido)-3-carbamoyloxy-methyl-3-cephem-4-carboxylic acid, by Streptomyces clavuligerus was studied. Addition of dl-valine-(14)C-1 to a fermentation of Cephalosporium acremonium gave cephalosporin C-(14)C-9 (I). The formation of deacetylcephalosporin C-(14)C-9 from I occurred at a greater rate in broths of S. clavuligerus than in the broths of C. acremonium, or in the autoclaved broths of S. clavuligerus. Diisopropylfluorophosphate partially inhibited the deacetylation of I in S. clavuligerus broth. An intracellular cephalosporin C esterase in S. clavuligerus could not be demonstrated. Although A16886A has been chemically synthesized from deacetylcephalosporin C, this reaction could not be demonstrated with S. clavuligerus.
mesh_terms: D000115:Acetylesterase / Q000378:metabolism*; D000215:Acylation; D002219:Carbamates / Q000096:biosynthesis; D002247:Carbon Isotopes; D002511:Cephalosporins / Q000096:biosynthesis*; D003470:Culture Media; D003864:Depression, Chemical; D007531:Isoflurophate / Q000494:pharmacology; D008738:Methyl Ethers / Q000096:biosynthesis; D009994:Osmolar Concentration; D013302:Streptomyces / Q000187:drug effects / Q000201:enzymology* / Q000378:metabolism
chemical_list: D002219:Carbamates; D002247:Carbon Isotopes; D002511:Cephalosporins; D003470:Culture Media; D008738:Methyl Ethers; D007531:Isoflurophate; D000115:Acetylesterase