Enzymatic Analysis, Quantitative Determination of L-Glutamic Acid by L-Glutamic Acid Decarboxylase (from E. coli)

Seidman, Murry; Blish, M. J.

doi:10.1021/jf60076a007

Cited by 6 publications

(3 citation statements)

References 8 publications

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“…One merit of the present system is that no complicated procedures are required. For example, amino acids are commonly detected by chromatographic separation followed by derivatization , and enzymatic reactions . Both methods require strict control of experimental conditions and complex sample treatment.…”

Section: Discussionmentioning

confidence: 99%

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Charge-Selective Aggregation Behavior of Thermoresponsive Polyelectrolytes Having Low Charge Density in Aqueous Solutions of Organic Counterions

2023

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The aggregation behavior of thermoresponsive polyelectrolytes with low charge density in aqueous solutions of organic counterions was investigated. We synthesized two thermoresponsive polyelectrolytes: anionic poly(N-isopropylacrylamide-co-(3-sulfopropyl)acrylamide potassium) (P-NIP-SPAK) and cationic poly(N-isopropylacrylamide-co-(3-acrylamidepropyl)trimethylammonium chloride) (P-NIP-AAPTAC). The polyelectrolytes remained soluble in their aqueous solutions even above the lower critical soluble temperature of P-NIP owing to the strong hydration property of the ionic groups. The aggregation occurred when organic counterions were added to the solution. In these solution systems, the concentration of counterions exceeds those of ionic groups introduced into the polyelectrolytes. The aggregation behavior is attributed to the salting-out effect of counterions accommodated near the polyelectrolyte surface by electrostatic interaction. This aggregation behavior was utilized for the charge-selective recognition of amino acids. P-NIP-SPAK aggregated only when basic amino acids were added under acidic conditions, whereas P-NIP-AAPTAC aggregated only when acidic amino acids were added under basic conditions. The results herein demonstrate that P-NIP-SPAK and P-NIP-AAPTAC have the potential to be used as charge-selective polymer sensors for amino acids without having to strictly control the experimental conditions.

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Section: Discussionmentioning

confidence: 99%

“…For example, amino acids are commonly detected by chromatographic separation followed by derivatization 43,44 and enzymatic reactions. 45 Both methods require strict control of experimental conditions and complex sample treatment. By contrast, the present method requires simple mixing and heating procedures.…”

Section: ■ Conclusionmentioning

confidence: 99%

Charge-Selective Aggregation Behavior of Thermoresponsive Polyelectrolytes Having Low Charge Density in Aqueous Solutions of Organic Counterions

2023

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“…Glucose was determined by the modified anthrone method of Ecker and Lockhart (4). Nonlabeled L-glutamate was measured by the specific decarboxylase-manometric technique of Seidman and Blish (14).…”

Section: Methodsmentioning

confidence: 99%

Energy Requirement for l -Glutamate Uptake and Utilization by Hansenula subpelliculosa Cells

Shieh

Hedrick

1966

J Bacteriol

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Energy requirement for L-glutamate uptake and utilization by Hansenula subpelliculosa cells. J. Bacteriol. 92:1638-1644. 1966.-Cells of the yeast Hansenula subpelliculosa require an energy source for the uptake of glutamate. A lag period of 20 to 40 min was required after the addition of glucose to the cells before glutamate uptake was initiated. When cells were preincubated in glucose, and washed with distilled water prior to the addition of glutamate, there was no lag period. Preincubation in glucose and glutamate lowered both the rate and the total uptake of glutamate as compared with cells preincubated in glucose alone. This is attributed to the partial utilization of the glucose-metabolite by glutamate or to the partial saturation of binding sites by glutamate during the preincubation period. Transport of glutamate by these yeast cells appears to be via a carrier, where energy is required for the binding of the amino acid to nonspecific binding sites. In addition to total uptake, some aspects of the Ct4-glutamate utilization were measured. Of the total uptake, 58% was metabolized and converted to C02, 25.2% remained in the soluble pool, and 16.8% was incorporated into trichloroacetic acid-insoluble products. When the available energy source was depleted, the processes of uptake, metabolism, and incorporation ceased, even though there was an ample supply of glutamate present within the cells. Removal of cells from glutamate and addition of glucose reinitiated the incorporation of glutamate into proteins and other trichloroacetic acid-insoluble compounds. Therefore, an additional energy source is required with this species of yeast for glutamate uptake, for the priming of mechanisms required for its metabolism, and for its incorporation. Cells of the yeast Hansenula subpelliculosa strain Y 1683 can readily use L-proline as a sole source of carbon, but they cannot use L-glutamic

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Immobilization of Brevibacterium flavum cells on collagen for the production of glutamic acid in a recycle reactor

Constantinides

Bhatia

Vieth

1981

Biotech & Bioengineering

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SummaryIn this study, live cells of Brevibacterium j7avum were immobilized for the production of glutamic acid. The reason for such a choice was that glutamic acid fermentation is an extensively studied fermentation and one which requires the viability of entire cellular faculties for the acid production. Brevibacterium flavum was chosen because it is an industrially used bacterium, and is very potent vis a vis glutamic acid production. Studies were performed to find aeration and agitation conditions for optimal growth and glutamic acid productivity. Experiments were also done to find the optimum harvesting time. The cell activity peaks during the run of fermentation, and the time at which the peak occurs, was found. Conventional methods for immobilizing the cells on collagen were found to be lacking.The pH and drying were the two main reasons for loss of viability of the cells; the latter being more important. A modified immobilization procedure has been devised, which can immobilize live cells at any given pH and ionic strength, in contrast to the conventional method which requires the pH to be above 1 1 or below 3. This new method involves dialysis of collagen in suitable dialysis bags against water at pH 7 (or buffer at any desired pH). The dialysed collagen blended at 20,000 rpm, resulted in a very smooth dispersion, unnoticeably different from collagen dispersion prepared at pH 11. The dispersed collagen was then cast and dried at an elevated temperature, and high air flow rate over the cast membrane, decreasing the time of drying from 6-8 hr (in the conventional method) to 1.5-2 hr. The membrane has been tested for glutamic acid producing capabilities in a column reactor with the membrane spirally wound. The reactor has been operated under continuous conditions for 5-10 days with stable activities.

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Enzymatic Analysis, Quantitative Determination of L-Glutamic Acid by L-Glutamic Acid Decarboxylase (from E. coli)

Abstract: and 1.6 mg. of toxaphene-i.e., 106%was recovered. A 45-gram butterfat sample, to which no toxaphene was added, was carried through the same procedure and no measurable interferences were encountered.

Cited by 6 publications

References 8 publications

Charge-Selective Aggregation Behavior of Thermoresponsive Polyelectrolytes Having Low Charge Density in Aqueous Solutions of Organic Counterions

Charge-Selective Aggregation Behavior of Thermoresponsive Polyelectrolytes Having Low Charge Density in Aqueous Solutions of Organic Counterions

Energy Requirement for l -Glutamate Uptake and Utilization by Hansenula subpelliculosa Cells

Immobilization of Brevibacterium flavum cells on collagen for the production of glutamic acid in a recycle reactor

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