• Microbiology and Biotechnology Letters
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• v.21 no.6
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• pp.527-533
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• 1993

Aminolevulinic acid(ALA) was shown to be synthesized via active pathways of either C4 or C5 ALA biosynthesis in cells of a photosynthetic bacterium, Rhodocyclus gelatinosus KUP-74, where the C5 pathway was appeared to be preferntially expressed in the cells. It was strongly suggested that L-glutamine might be utilized more effectively than L-glutamate to synthesize ALA via C5 pathway in this bacterium from the fact of relationship between the cellular uptake rates of glutamate and its Gamma-derivaties and corresponded ALA productivities in vitro and in vivo.

• Applied Biological Chemistry
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• v.37 no.6
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• pp.427-432
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• 1994

The effectiveness of the resting cells of a photosynthetic bacterium, Rhodocyclus gelatinosus KUP-74, was investigated on the production of extracellular ${\delta}-aminolevulinate$ (ALA). The ALA generating system with 1.05 mg cells per milliliter required 6 hr-incubation to obtain maximal yield of extracellular ALA. Under this condition ALA inducers, i.e., levulinate or L-glutamate showed relatively low effects to increase extracellular ALA production. Instead, the volume of the system and proper cell density appeared to be important factors for effective production of the ALA. The life-span of the resting cells was remarkably extended to maintain stable production of the ALA by immobilization of cells.

• Journal of Microbiology and Biotechnology
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• v.3 no.4
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• pp.244-251
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• 1993

A novel system has been developed to produce ${\delta}-aminolevulinic$ acid (ALA) using the intact cells of late logarithmic phase of Rhodocyclus gelatinosus KUP-74. The system was shown optimum yield of extracellular ALA under a condition of anaerobic light irradiation (4 Klux) at $30^{\circ}C$ with no variation in cell mass. The rate of extracellular ALA formation was stimulated by low doses of either $C_4\;or\;C_5$ ALA biosynthetic precursors, where 5 mM ($C_4) and 3 mM ($C_5) of each precursors were appeared to generate the maximum rates of 3.3 and 4.0 nmoles of ALA per 0.35 mg cells per hr, respectively. Half-life of the system was 10 hr in a sense of an ability of portage transport of L-glutamate, and sequential dose of this compound was resulted in promising recovery of the ALA.

• Applied Biological Chemistry
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• v.38 no.1
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• pp.1-6
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• 1995

An optimal condition for the continuous production of ${\delta}-aminolevulinate$(ALA) was investigated using high concentrated resting cells of Rhodocyclus gelatinosus KUP-74. The increase of the amount of extracellular ALA versus the concentration of resting cells showed rectangular hyperbolic pattern until 20 mg cells/ml, but no further increase in the ALA amount by increasing its concentration was occurred. The highest yield of the extracellular ALA was observed after 3 hr of incubation of 1 ml reaction system containing 20 mg cells, 4 mM levulinate and 5 mM L-glutamate. On the other hand, the immobilized cells prepared by Ca-alginate inclusive method needed to incubate for 6 hr with 6 mM levulinate and 10 mM L-glutamate to give maximal yield of the extracellular ALA. In addition, under these conditions the resulted continuous productivities of the ALA by immobilized cells and highly concentrated resting cells were appeared 50 percent decreases after incubations for 185 hr and 100 hr, respectively, and the method of the cells to be immobilized was more efficient to recover the extracellular ALA produced.

• Applied Biological Chemistry
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• v.35 no.3
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• pp.210-217
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• 1992

A photosynthetic bacterium strain KUP-74 producing high amount of S-amino-levulinic acid(ALA) was isolated from soils, which was identified as Rhodocyclus gelatinosus. After 10 days cultivation under anaerobic-light condition at $30^{\circ}C$, 4 Klux and pH 6.8, 5 mg/l of ALA was formed extracellularly. ALA productions were increased up to 8 mg/l and 12 mg/l in cell cultivations either by the addition of 0.5% glycerol (v/v) or 10 mM of glycine and succinic acid, respectively, using Lascelles basal medium eliminated L-glutamic acid. By cultivation in the presence of 30 mM each D,L-glutamic acids and D,L-glutamines the yield of ALA showing a late induction phenomenon was reached the maximum value of 21 mg/l. Different culture times were needed to generate maximum ALA yields by the addition of initial precursors of $C_4$ and $C_5$ pathways in basal medium, as being 107 h and 262 h, respectively. 40 mg/l yield of ALA was observed by cell cultivation with the basal medium containing each 10 mM levulinic acid(LA) and glycine simultaneously.