| abstract |
Mutant microbial strains, which are capable of overproducing phenylalanine ammonia-lyase and are useful for the production of L-phenylalanine, may be selected by growing cells on a minimal nutritional medium containing, as substantially the sole carbon source, a phenylalanine analogue, said phenylalanine analogue being a substrate for PAL and the PAL-catalyzed breakdown of said phenylalanine analogue being the rate-determining step for its.overall metabolism. |