Microbiological Synthesis
Mostrando 13-24 de 32 artigos, teses e dissertações.
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13. Microbiological Method for the Determination of l-Tryptophan
Sebek, Oldrich K. (The Upjohn Company, Kalamazoo, Mich.). Microbiological method for the determination of l-tryptophan. J. Bacteriol. 90:1026–1031. 1965.—The ability of Chrombacterium violaceum to utilize l-tryptophan for the synthesis of a purple pigment, violacein, served as a basis for the development of a quantitative estimation of this amino acid. T
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14. Measurement of Microbial Activity and Growth in the Ocean by Rates of Stable Ribonucleic Acid Synthesis
A relatively simple and extremely sensitive technique for measuring rates of stable ribonucleic acid (RNA) synthesis was devised and applied to bacterial cultures and seawater samples. The procedure is based upon the uptake and incorporation of exogenous radiolabeled adenine into cellular RNA. To calculate absolute rates of synthesis, measurements of the spe
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15. Sensitive biological detection method for tetracyclines using a tetA-lacZ fusion system.
A sensitive microbiological detection system for tetracyclines, utilizing an Escherichia coli strain containing a cloned tetA-lacZ gene fusion, is described. Expression of beta-galactosidase by the fusion plasmid pUB3610 remained subject to regulatory control by the TetR repressor protein, with the presence of tetracyclines in the growth medium leading to a
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16. Microbiological Systems in Organic Synthesis: Preparative-Scale Resolution of (RS)-Glaucine by Fusarium solani and Stereospecific Oxidation of (R)-(−)-Glaucine by Aspergillus flavipes
The destructive resolution of (6aR,S)-glaucine (Ic) was accomplished by oxidation of the (6aS)-(+)-enantiomer (Ia), using Fusarium solani ATCC 12823 to yield the unnatural alkaloid (6aR)-(−)-glaucine (Ib). Eighteen cultures were examined for their ability to metabolize the (6aR)-(−)-enantiomer (Ib), and Aspergillus flavipes ATCC 1030 was found to catalyz
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17. Microbiological Production of Carotenoids: VIII. Influence of Hydrocarbon on Carotenogenesis by Mated Cultures of Blakeslea trispora
Synthesis of β-carotene by mated strains of Blakeslea trispora in shaken-flask culture was considerably enhanced by adding either 5% kerosene after 2 days of fermentation or acid-refined kerosene at the start of fermentation to a grain-based medium that also contained a natural lipid, nonionic detergent, and β-ionone; average yields of 17,500 μg per g of
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18. Biosynthesis of Biotin in Microorganisms V. Control of Vitamer Production
Use of a yeast-lactobacillus differential microbiological assay permitted investigation into the synthesis of biotin vitamers by a variety of bacteria. A major portion of the biotin activity was found extracellularly. The level of total biotin (assayable with yeast) greatly exceeded the level of true biotin (assayed with lactobacillus). Values for intracellu
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19. Microbial transformations of warfarin: stereoselective reduction by Nocardia corallina and Arthrobacter species.
The microbiological metabolism of warfarin was examined as a model of metabolism in higher organisms, including humans, and to determine the chirality of microbial reductases for application in organic synthesis. Nineteen cultures were examined based on their reported abilities to reduce ketonic substrates, and several were shown to catalyze the desired reac
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20. Enhancement of β-Carotene Synthesis by Citrus Products
β-Ionone, a stimulatory compound in the microbiological production of β-carotene by mated cultures of Blakeslea trispora, could be replaced with low-cost agricultural by-products (citrus oils, citrus pulp, or citrus molasses) with as good or better carotene yields. Peak yields (81 to 129 mg of carotene per g of dry solids) were achieved in 5 days. The vari
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21. Biosynthesis of Biotin: Synthesis of 7,8-Diaminopelargonic Acid in Cell-Free Extracts of Escherichia coli
Cell-free extracts prepared from a biotin auxotroph of Escherichia coli were active in catalyzing the synthesis of 7,8-diaminopelargonic acid, an intermediate of the biotin pathway, from 7-oxo-8-aminopelargonic acid. The product was identified on the basis of its chromatographic characteristics and its biotin activities for biotin auxotrophs of E. coli. Enzy
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22. Overproduction of 3'-aminoglycoside phosphotransferase type I confers resistance to tobramycin in Escherichia coli.
Escherichia coli HM69, isolated from urine, was resistant to high levels of kanamycin (MIC, > 1,000 micrograms/ml) and a low level of tobramycin (MIC, 8 micrograms/ml). Phosphocellulose paper-binding assays and molecular cloning indicated that resistance to both aminoglycosides was due to synthesis of a 3'-aminoglycoside phosphotransferase type I, an enzyme
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23. EFFECT OF URIC ACID ON RIBOFLAVINE PRODUCTION BY INTESTINAL COLIFORM BACTERIA
Lau, H. S. (University of Kentucky, Lexington), and R. F. Wiseman. Effect of uric acid on riboflavine production by intestinal coliform bacteria. J. Bacteriol. 87:337–340. 1964.—Cultures of Escherichia coli, Aerobacter aerogenes, and Paracolobactrum species, isolated from human feces and from intestinal contents of rats, were tested for riboflavine synth
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24. Opine Synthesis in Wild-Type Plant Tissue
Opine production is associated with crown gall tissue, a neoplastic growth caused by infection of dicotyledonous plants with Agrobacterium tumefaciens. Recent publications have claimed that tissues of certain monocotyledonous plants can also be infected by Agrobacterium. Following infection, a part of the Agrobacterium Ti plasmid, T-DNA, is integrated into t