Strain Improvement of Rhodotorula graminis for Production of a Novel l-Phenylalanine Ammonia-Lyase
AUTOR(ES)
Orndorff, Steve A.
RESUMO
l-Phenylalanine ammonia-lyase (PAL; EC 4.3.1.5) from Rhodotorula rubra has been used in the commercial manufacture of l-phenylalanine from trans-cinnamic acid. In this study, R. graminis PAL was investigated. Mutant strain GX6000 was isolated after ethyl methanesulfonate mutagenesis of wild-type R. graminis GX5007 by selecting for resistance to phenylpropiolic acid, an analog of trans-cinnamic acid. Mutant strain GX6000 produced inducible PAL at levels four- to fivefold higher than had wild-type R. graminis. Furthermore, this strain had several other physiological traits that make it more commercially useful than R. rubra. For example, during fermentation, the PAL half-life was three- to fivefold longer, PAL specific activity was six to seven times higher, and PAL synthesis was significantly less inhibited by temperatures above 30°C. Induction of PAL in strain GX6000 appeared to be less tightly regulated; l-leucine acted synergistically with l-phenylalanine, the physiological inducer, to increase the PAL specific activity and titer to 165 U/g (dry weight) and 3,000 U/liter, respectively, a 40% increase over the effect of l-phenylalanine alone. Strain GX6000 PAL showed significantly greater stability in bioreactors for the synthesis of l-phenylalanine, a finding that is consistent with the stability properties observed during fermentation.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=202586Documentos Relacionados
- Production of l-Phenylalanine from trans-Cinnamic Acid with Rhodotorula glutinis Containing l-Phenylalanine Ammonia-Lyase Activity
- Regulation of L-phenylalanine ammonia-lyase by L-phenylalanine and nitrogen in Neurospora crassa.
- Regulation of L-phenylalanine ammonia-lyase from Rhizoctonia solani.
- l-Phenylalanine Ammonia-lyase (Maize): Partial Purification and Response to Gibberellic Acid and Cycloheximide of l-Phenylalanine and l-Tyrosine Ammonia-lyase Activities 1
- l-Phenylalanine Ammonia-Lyase (Maize): Evidence for a Common Catalytic Site for l-Phenylalanine and l-Tyrosine 1
