title: Biological production of optically active muconolactones by Rhodococcus rhodochrous.
abstract: Optically active (-)-3-methylmuconolactone was biologically produced using a mutant strain of Rhodococcus rhodochrous N75 that is capable of metabolizing 4-methylcatechol via a modified ortho-cleavage pathway. The mutant strain (CJ30) was prepared by mutagenesis using N-methyl-N'-nitro-N-nitrosoguanidine and found to be blocked in the degradation of 3-methyl-muconolactone. Cells of the mutant CJ30, which had been previously grown on yeast extract and induced with p-toluate, transformed p-toluate (11.5 mM) to optically active (-)-3-methylmuconolactone with a yield of 53%. The structure of 3-methylmuconolactone was confirmed by NMR spectroscopy and mass spectrometry. Cell-free extracts of R. rhodochrous N75 also transformed a range of 4-alkylcatechols, such as 4-ethylcatechol, 4-iso-propylcatechol, and 4-tert-butylcatechol, to the corresponding 4-alkyl-substituted muconolactones.
authors.affiliation: Institute of Biotechnology, University of Cambridge, UK. ccha@nctr.fda.gov
authors.forename: C J
authors.initials: CJ
authors.lastname: Cha
mesh_terms: D003470:Culture Media; D007783:Lactones / Q000737:chemistry / Q000378:metabolism*; D016296:Mutagenesis; D012240:Rhodococcus / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*; D013237:Stereoisomerism
chemical_list: C116618:3-methylmuconolactone; D003470:Culture Media; D007783:Lactones