title: Phenylalanine ammonia lyase production by gamma irradiated and analog-resistant mutants of Rhodotorula glutinis.
abstract: Mutants resistant to phenylalanine analogs (L-tyrosine, p-fluoro-D, L-phenylalanine (PFP) and trans-cinnamic acid) were isolated from a wild type strain of Rhodotorula glutinis A-97 by mutagenic treatment with gamma radiation and screened for phenylalanine ammonia lyase (PAL) production. One such mutant, gammaT11 (resistant to L-tyrosine), exhibited four times the PAL activity of the parent wild strain A-97. Mutant isolate gammaTFP5.6 which was selected as L-tyrosine and PFP resistant isolate, produced inducible PAL activity at levels 5.94-fold higher than the wild-type A-97 and 2.66-fold higher than its parent mutant isolate gammaT5 which was resistant to L-tyrosine. The mutant isolate gammaTC5d which was resistant to L-tyrosine and trans-cinnamic acid, exhibited 3.48 and 1.56-fold increase in PAL activity compared to the parent wild strain A-97 and its parent mutant isolate gammaT5, respectively. Different media have been examined for the induction of PAL.
authors.affiliation: National Center for Radiation Research and Technology, Nasr City, Cairo, Egypt.
authors.forename: A I
authors.initials: AI
authors.lastname: El-Batal
authors.forename: M A
authors.initials: MA
authors.lastname: Abo-State
authors.forename: A
authors.initials: A
authors.lastname: Shihab
mesh_terms: D002934:Cinnamates / Q000494:pharmacology; D003470:Culture Media; D004352:Drug Resistance, Microbial; D005720:Gamma Rays; D009154:Mutation; D010650:Phenylalanine Ammonia-Lyase / Q000096:biosynthesis*; D012248:Rhodotorula / Q000187:drug effects / Q000201:enzymology* / Q000235:genetics / Q000528:radiation effects; D014443:Tyrosine / Q000494:pharmacology; D010135:p-Fluorophenylalanine / Q000494:pharmacology
chemical_list: D002934:Cinnamates; D003470:Culture Media; C029010:cinnamic acid; D014443:Tyrosine; D010135:p-Fluorophenylalanine; D010650:Phenylalanine Ammonia-Lyase