• KSBB Journal
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• v.6 no.3
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• pp.321-325
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• 1991

In thisstudy, effects of medium components on microbial production of L-phenylalanine by Corynebacterium glutamicum were investigated. The effect of carbon source on the production of L-phenylalanine was significant. Molasses enhanced the production of L-phenylalanine compared to sucrose, glucose, fructose, or their mixture. It was noticed that trace salts were required for the cell growth and product formation in the minimal medium, but excess amounts of trace salts had no effect on the production of L-phenylalanine. It was also found that optimum amounts of biotin and thiamine were required for the cell growth and the production of L -phenylalanine.

• Microbiology and Biotechnology Letters
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• v.15 no.2
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• pp.80-83
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• 1987

During the enzymatic production of L-phenylalanine exploiting L-phenylalanine ammonia lyase(E.C 4.3.1.5) and trans-cinnamic acid, the conversion yield of L-phenylalanine and the stability of L-phenylalanine ammonia-lyase per so or induced Rhodotorula glutinis IFO 0559 were investigated. And the glycerol added to the conversion reaction as stabilizer had effect only on L-phenylalanine and made it possible to obtain the 80％ conversion yield from trans-cinnamic acid. In addition, the more rapid and reliable method than the thin layer chromatography for determining the conversion yield will be disscused.

• KSBB Journal
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• v.5 no.2
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• pp.125-131
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• 1990

Microbial production of L-phenylalanine using Corynebacterium glutamicum ATCC 21674, a tyrosine auxotroph resistant to aromatic amino acid analogues, has been studied and kinetic analysis was performed. Even though the strain was reported as a tyrosine auxotroph, it produced tyrosine and was able to grow on the minimal medium where no tyrosine was present. The average specific growth rate at the exponential growth phase was 0.087 hr-1. There was a dissociation of growth from the formation of the product. Linear correlation between biomass production and total CO2 production was obtained. The relationship between CO2 evolution rate and sugar consumption rate was also found to be linear.

• Journal of Microbiology and Biotechnology
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• v.8 no.3
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• pp.237-244
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• 1998

A study was carried out to elucidate the relation between the production of flavonol glycosides and the change of phenylalanine ammonia-lyase activity in cell suspension cultures of Ginkgo biloba by the unassisted and synergistic effects of various factors. The quercetin production showed a mixed-growth-associated pattern in cell suspension cultures. Fluorescent light and UV radiation increased phenylalanine ammonia-lyase (PAL) activity, and resulted in the increase of the production of quercetin and kaempferol ten- and four-fold, respectively, as compared to that obtained in the normal culture condition. The cell growth of Ginkgo biloba was enhanced .at higher temperatures whereas the quercetin production was at its maximum at low temperatures. Moreover, the quercetin production was increased by temperature change during the culture period. In particular, the quercetin production was at the highest level when the culture temperature was elevated from $10^{\circ}C\;to\;30^{\circ}C$. The addition of phenylalanine as a precursor in the culture medium stimulated an 8-fold increase in the production of quercetin; the addition of naringenin caused a l0-fold increase. The quercetin production was also greatly increased by feeding enzyme cofactors such as 2-ketoglutarate and ascorbic acid in the culture medium, but specific PAL activity was not increased except with phenylalanine feeding. The synergistic effect of UV radiation and naringenin feeding was observed, resulting in the increase of flavonol glycoside production at a rate higher than in any other case investigated.

• Microbiology and Biotechnology Letters
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• v.19 no.5
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• pp.433-438
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• 1991

The plasmid pSY130-14 for the high production of phenylalanine is a temperaturecontrollable expression vector composed of the $P_R$ and the $P_L$ promoter and a temperature sensitive repressor, $cI_{857}$ of bacteriophage lambda. Strain AT2471 harbouring plasmid pSY13O- 14 is induced the phenylalanine production by shifting up the incubation temperaure to $38.5^{\circ}C$. Plasmid stability of E. coli AT2471 harbouring pSY130-14 was very low, it was about 30% after 48 h cultivation at $38.5^{\circ}C$ without kanamycin. The plasmid disappeared immediately at $40^{\circ}C$ without kanamycin, and at $40^{\circ}C$ adding kanamycin, the plasmid stability decreased at the beginning, but rose with the extension of the culture time. For the improvement of plasmid stability, the plasmid obtaind was designated as pSY15O-1 by changing origin region (ori) pACYC 177 of pSY130-14 for ori pSC101. E. coli AT2471 harbouring pSY150-1 was stable at $38.5^{\circ}C$ without tetracycline, and the plasrnid stability was about 40% after 48 h cultivation at $40^{\circ}C$.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.13-19
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• 1995

In order to produce phenylalanine without tyrosine co-production, we constructed various temperature-controllable expression vectors by insertion of lower expression of the tyrA gene into the plasmid pSY130-14. And tyrosine revertant to cultivate without addition of tyrosine, was selected from Escherichia coli strain AT2471[tyrA , thi ] by spontaneous mutation. The strain AT2471 harbouring plasmid pSY146A and the tyrosine revertant 5 harbouring plasmid pSY111-14 produced 12 g/l and 15 g/l of phenylalanine respectively in a 2.5 l jar fermenter at a constant temperature of $39^{\circ}C$ after 55 hours cultivation.

• Food Science and Biotechnology
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• v.18 no.4
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• pp.954-958
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• 2009

Effects of controlled- and uncontrolled-pH operations on phenylalanine ammonia lyase (PAL) production by a recombinant Escherichia coli strain were investigated at uncontrolled-pH ($pH_{UC}$) and controlled-pH ($pH_C$) of 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, and 8.5 in bioreactor systems. The results showed that the recombinant PAL activity was improved significantly by controlled pH strategy. Among the $pH_C$ operations, the highest PAL activities were obtained under $pH_C$ 7.5 strategy where cell mass ($OD_{600\;nm}$) and PAL activity was 1.3 and 1.8 fold higher than those of $pH_{UC}$, respectively. The maximum PAL activity reached 123 U/g. The $pH_C$ 7.5 strategy made recombinant plasmid more stable and therefore allowed easier expression of PAL recombinant plasmid, which increased PAL production. It was indicated that the new approach (controlled-pH strategy) obtained in this work possessed a high potential for the industrial production of PAL, especially in the biosynthesis of L-phenylalanine.

• The Korean Journal of Food And Nutrition
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• v.9 no.1
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• pp.21-28
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• 1996

This study was attempted to investigate the production of L-tyrosine by Brevibacterium flavum ATCC 14067. To select the strain which produce more L-tyrosine, mutants were induced by N-methyl-N'-nitro-nitrosoguanidine (NTG) treatment and phenylalanine auxotrophic mutants were induced by NTG and penicillin treatments. PFP resistant mutant was isolated from a phenylalanine auxotroph by retreatment with NTG and screened for increase of L-tyrosine production. PFP-326 mutant resistant to PPP (100ug/ml) was derived from phenylalanine auxotroph by mutagenesis with NTG and PFP-106 mutant resistant to PFP (1201g/ml) was derived from PFP-326 by mutagenesis with NTG. The composition of media for L-tyrosine production in strain PFP-106 was studied. PFP-106 mutant strain produced 50mg 11 of L-tyrosine while the parent strain produced 0.56mg 11 of L-tyrosine. The optimum composition of medium for L-tyrosine by strain PFP-106 was 10cA sucrose as carbon source, 3% ammonium sulfate as nitrogen source. The optimum cultural condition for producing L-tyrosine by strain PFP-106 was L-phenylalanine at a concentration of 1000g/mg.

• Korean Journal of Pharmacognosy
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• v.27 no.4
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• pp.301-308
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• 1996

Hairy roots induced from stems of Rubia cordifolia var. pratensis were cultured in the liquid medium under a variety of auxins to find the optimal condition for the growth and production of pigments. Culture of the hairy roots on NN liquid medium containing NAA 0.5 mg/l was best for growth of hairy roots. Production of yellow anthraquinone derivatives and purpurin in hairy roots was enhanced by the culture on NN liquid medium without auxins. Effects of L-phenylalanine, L-tyrosine and juglone, synthesized via the shikimic acid pathway, on growth and production of pigments in hairy roots were studied in the present study. Concentration of exogeneous L-phenylalanine. L-tyrosine and juglone in liquid culture system of hairy root containing NAA 0.1 mg/l was decreased quickly in its early stages of the culture period. Addition of juglone to NN liquid medium containing NAA 0.1 mg/l enhanced the productivity of pigments in hairy roots.

• Applied Biological Chemistry
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• v.31 no.4
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• pp.376-381
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• 1988

The optimal reaction conditions were investigated to produce L-phenylalanine from transcinnamic acid and ammonia by Rhodotorula glutinis IFO 0559. The highest amount of L-phenylalanine was produced when the reaction mixture containing 200mM of traps-cinnamic acid, 4M of $NH_4OH$, 250mM of $(NH_4)_2SO_4$, 0.005% of cetylpyridinium chloride (pH 10.5) and 50mg/ml of dry cell was used. Among the nonaqueous organic solvents, petroleum ether was the most effective on the production of L-phenylalanine. The optimal concentration of petroleum ether in the reaction mixture was 50%. Under the optimal conditions, 21.1g/l of L-phenylalanine was produced in 12hr, and the yield was 63.9% based on transcinnamic acid.