title: Studies on the cell-free biosynthesis of beta-lactam antibiotics.
abstract: Cell walls of Cephalosporium acremonium mycelia were lysed by enzyme preparations from either Helix pomatia (snail) digestive juice or Cytophaga. The yield of protoplasts depended on the lytic-enzyme preparation and the age of the culture, and it increased after the mycelia were pretreated with dithiothreitol. A cell-free preparation, obtained by osmotic lysis of protoplasts, synthesized labelled penicillin N from L-[14C]valine. Approx. 0.03-0.06% of the amino acid was incorporated into penicillin N. Under conditions of penicillin N synthesis, the broken-protoplast preparation failed to produce significant amounts of cephalosporin C or its precursors, deacetylcephalosporin C and deacetoxycephalosporin C.
mesh_terms: D000164:Acremonium / Q000378:metabolism*; D002474:Cell-Free System; D002511:Cephalosporins / Q000096:biosynthesis; D002845:Chromatography; D010406:Penicillins / Q000096:biosynthesis* / Q000302:isolation & purification; D011523:Protoplasts; D014633:Valine / Q000378:metabolism
chemical_list: D002511:Cephalosporins; D010406:Penicillins; D014633:Valine