Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Repression of biosynthetic enzyme synthesis in Pseudomonas putida is incomplete even when the bacteria are growing in a nutritionally complex environment. The synthesis of four of the enzymes of the arginine biosynthetic pathway (N-acetyl-alpha-glutamokinase/N-acetylglutamate-gamma-semialdehyde dehydrogenase, ornithine carbamoyltransferase and acetylornithine-delta-transaminase) could be repressed and derepressed, but the maximum difference observed between repressed and derepressed levels for any enzyme of the pathway was only 5-fold (for ornithine carbamoyltransferase). No repression of five enzymes of the pyrimidine biosynthetic pathway (aspartate carbamoyltransferase, dihydro-orotase, dihydro-orotate dehydrogenase, orotidine-5'-phosphate pyrophosphorylase and orotidine-5'-phosphate decarboxylase) could be detected on addition of pyrimidines to minimal asparagine cultures of P. putida A90, but a 1-5- to 2-fold degree of derepression was found following pyrimidine starvation of pyrimidine auxotrophic mutants of P. putida A90. Aspartate carbamoyltransferase in crude extracts of P. putida A90 was inhibited in vitro by (in order of efficiency) pyrophosphate, CTP, UTP and ATP, at limiting but not at saturating concentrations of carbamoyl phosphate.
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PMID:Regulation of arginine and pyrimidine biosynthesis in Pseudomonas putida. 17 12

A freshwater Spirillum sp., which apparently belongs to a niche of low nutritional status (Matin & Veldkamp, 1978), accumulated poly-beta-hydroxybutyric acid (PHB) during lactate-limited growth in continuous culture. The PHB content varied in a complex manner with the dilution rate (D), but was greatest at the lowest D value examined: about 18% (w/w) at D = 0.025 h-1. It is not known what mechanism accounted for PHB accumulation during carbon-limited growth. The resistance of cultures of Spirillum sp. to starvation after growth at various D values was compared with that of a Pseudomonas sp. which appears to belong to relatively richer environments (Matin & Veldkamp, 1978) and does not accumulate PHB. In Spirillum sp., resistance correlated directly with the PHB content of the culture subjected to starvation, whereas in Pseudomonas sp. it increased with RNA content. Further, after growth at D = 0.03 to 0.05 h-1, the Spirillum sp. was much more resistant to starvation than was the Pseudomonas sp. Since the microflora of oligotrophic environments are probably often subjected to starvation conditions, PHB accumulation by Spirillum sp. during growth in such environments may assist survival. PHB in Spirillum sp. was rapidly degraded during starvation but it had no sparing effect on RNA degradation. It is not known how PHB enhanced resistance to starvation.
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PMID:Selective advantage of a Spirillum sp. in a carbon-limited environment. Accumulation of poly-beta-hydroxybutyric acid and its role in starvation. 22 10

The lipid-containing bacteriophage PR4 is of special intest because it can replicate in various gram-negative bacteria, including Escherichia coli, that carry one of a group of drug resistance plasmids. PR4 grown in E. coli strain PS2R contains about 10% lipid by weight, with the negatively charged phospholipid phosphatidylglycerol being the most abundant lipid in the virion. We now report the following. (i) PR4 attaches to E. coli with an attachment rate constant of Ka approximately 6.2 X 10(-10) ml/min, which is about twice that of the enveloped phage phi6 (to Pseudomonas phaseolicola), but a factor of 5 less than that of phage PM2 (to Pseudomonas BAL-31). (ii) Use of an E. coli glycerol auxotroph indicated that a normal amount of PR4 replication occurs only if glycerol starvation (inhibition of all phospholipid synthesis) begins no earlier than about halfway through the lytic cycle. (iii) Use of an E. coli fatty acid synthesis temperature-sensitive mutant and an E. coli phosphatidylethanolamine synthesis temperature-sensitive mutant indicate that PR4 replication can occur in the absence of either normal fatty acid synthesis or normal phospholipid synthesis if the infection takes place prior to the termination of overall cell growth and the onset of cell death, (iv) Whereas PR4 burst size in nutrient media at 30 degrees C to 42%C is about 40, the burst size at 20 degrees C is less than 3, Temperature-shift experiments show that the temperature late in infection determines the burst size.
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PMID:Effects of temperature and host cell genetic characteristics on the replication of the lipid-containing bacteriophage PR4 in Escherichia coli. 32 29

Three isolates, a Pseudomonas sp., a Bacillus sp. and an Arthrobacter sp., which had been isolated from a meadow soil at Devon Island, Canada, were subjected to starvation under varying conditions. The viabilities of the three isolates during starvation for 30 days in a carbon-free medium was assessed after the organisms had been grown continuously at varying rates in carbon- and nitrogen-limited media at 5 and 15 degrees C. Pseudomonas M216 was the most resistant to starvation stress, Bacillus M153 the least, and Arthrobacter M51 was intermediate in its response. Cells grown and starved at 5 degrees C survived longer than those at 15 degrees C. Carbon-limited Bacillus and Arthrobacter cells grown at high rates prior to starvation survived longer than those grown slowly, while in nitrogen-limited Arthrobacter the reverse was observed. The pattern of endogenous metabolism of the three isolates during starvation at 15 degrees C for 10 days was similar to that observed in other organisms. Levels of endogenous substrates such as carbohydrate and protein showed a rapid decrease in the initial 20 h of starvation, followed by a gradual decline over the remainder of the starvation period. The rates of endogenous metabolism of the isolates were positively correlated with their survival rates during starvation.
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PMID:Effect of starvation on survival of three bacterial isolates from an arctic soil. 74 9

The complex problems of microbiological degradation of synthetic plastics and a fairly wide variety of 62 testing materials, belonging to 14 major groups of plastics, are described. Adaequate and reliable testing techniques had to be devised. Drawing on the experiences of H. Braun, 1930, and of Bushnell and Haas, 1941, as to the metabolism of bacteria and the utilization of certain hydrocarbons by microorganisms, and previous research work by A. Schwartz in Berlin, 1959-60, on microbial corrosion of plastics, methods of laboratory testing were developed. The bacteriological technique was based on selection of aerobic microorganisms, which were, by starvation, adapted to use the plastic materials as their only carbon source; foreign carbon sources had to be strictly eliminated; emphasis was laid on proper, double control cultures. The test organisms involved included P. aeruginosa and fluorescens strains, also a certain species of Candida, and mixtures of soil, sewage and garbage organisms grown on exposed plastic surfaces. By means of series of passages the selective adaptation and conservation of these organisms was continued up to 4 1/2 years. An anaerobic adaptation method for Desulfovibrio desulfuricans was developed and used successfully. After preliminary experimentation (Soil burial, sewage and garbage exposure tests) in the laboratory as well as in the open, a large scale Field testing programme under realistic and to some extent extreme conditions was implemented: Nine different plastic materials comprising eight plain high polymer plastics and for comparison one synthetic Cellulose derivate, together with glass control samples, were exposed in twelve different sewage, garbage, and soil media over a period of 3 months to 2 years, and subsequently examined. On the basis of the bacteriological results obtained from the adaptation series the test materials were classified into three categories, corresponding to the stimulation of bacterial growth: Group one, which allowed strong proliferation, included certain types of plasticized P.V.C. and Cellulose esters, as expected, and, as a new result, Polyurethane rubber; the latter showed clear signs of surface corrosion. Group two, which induced a clear but moderate growth, comprised a nylon trade type of Polyamide. Gruop three, allowing weak but still recognisable growth, included Formaldehyde pressure resing (Bakelite). This was surprising as it was thought that the formaldehyde and phenol components would exert a bacteriocidic or at least bacteriostatic effect. The results of the long and time consuming adaptation series with Pseudomonas aeruginosa were confirmed by the manometric dissimilation method of O. Warburg by means of the Braun/Melsungen apparatus. With this subtle but elegant procedure results and graphical recordings were obtained within hours and days...
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PMID:[Mutual relations between plastic materials and bacteria (author's transl)]. 82 69

We investigated the degradation of radioisotopically labeled intracellular protein in starved, intact cells of Pseudomonas putida P2 (ATCC 25571) and the regulation of this process. Intracellular protein isotopically labeled with L-[4,5-3H]leucine during log-phase growth at 30 C is degraded at rates of 1 to 2%/h in log-phase cells and 7 to 9%/h in starved cells. Rifampin, chloramphenicol, and tosyllysine chloromethylketone lower the rate of protein degradation by starved cells. Addition to starved cells of a nutrient upon which the culture is induced for growth rapidly lowers the rate of protein degradation from 7 to 9%/h to less than 1.5%/h. A nutrient that is oxidized but that cannot immediately support growth also lowers the rate of starvation-induced protein degradation. Proteolytic activity of cell extracts requires a divalent metal ion and may be inhibited up to 60% by tosyllysine chloromethylketone or p-toluenesulfonyl fluoride. Rifampin and chloramphenicol have no effect. In contrast to intact cells, extracts of growing or starving cells degrade protein at equivalent rates. We also investigated the stabilities of the inducible transport system and of four inducible intracellular enzymes of L-arginine catabolism. These include: the membrane-associated, L-arginine-specific transport system; L-arginine oxidase (oxidase); alpha-ketoarginine decarboxylase (decarboxylase); gamma-guanidinobutyraldehyde dehydrogenase ( dehydrogenase); and gamma-guanidinobutyrate amidinohydrolase (hydrolase). In starved cells, the rates of loss of activities were: transport and dehydrogenase activities, stable; oxidase and decarboxylase activities, 20 to 30%/h; hydrolase activity, 5 to 8%/h. Chloramphenicol decreases the rate of loss of oxidase, decarboxylase, and hydrolase activity, whereas p-toluenesulfonyl fluoride lowers the rate of loss of decarboxylase but not of oxidase or hydrolase activity. Addition to starved cells of a nutrient for which they are already induced for growth (e.g., malate, a noninducer of arginine catabolic enzymes) decreases the rate of loss of oxidase and decarboxylase activity but not that of the hydrolase.
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PMID:Physiological consequences of starvation in Pseudomonas putida: degradation of intracellular protein and loss of activity of the inducible enzymes of L-arginine catabolism. 119 37

The 2,4-dichlorophenoxyacetic acid (2,4-D) degrading pseudomonad, Pseudomonas cepacia DBO1(pRO101), was inoculated at approximately 10(7) CFU/g into sterile and non-sterile soil amended with 0, 5 or 500 ppm 2,4-D and the survival of the strain was studied for a period of 44 days. In general, the strain survived best in sterile soil. When the sterile soil was amended with 2,4-D, the strain survived at a significantly higher level than in non-amended sterile soil. In non-sterile soil either non-amended or amended with 5 ppm 2,4-D the strain died out, whereas with 500 ppm 2,4-D the strain only declined one order of magnitude through the 44 days. The influence of 0, 0.06, 12 and 600 ppm 2,4-D on short-term (48 h) survival of P. cepacia DBO1(pRO101) inoculated to a level of 6 x 10(4), 6 x 10(6) or 1 x 10(8) CFU/g soil was studied in non-sterile soil. Both inoculum level and 2,4-D concentration were found to have a positive influence on numbers of P. cepacia DBO1(pRO101). At 600 ppm 2,4-D growth was significant irrespective of the inoculation level, and at 12 ppm growth was stimulated at the two lowest inocula levels. P. cepacia DBO1(pRO101) was able to survive for 15 months in sterile buffers kept at room temperature. During this starvation, cells shrunk to about one third the volume of exponentially growing cells.
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PMID:Growth and survival of Pseudomonas cepacia DBO1 (pRO101) in soil amended with 2,4-dichlorophenoxyacetic acid. 128 55

Under iron-starvation conditions of growth, Pseudomonas fluorescens CHA0, a soil isolate involved in phytopathogenic fungi antagonisms, produced, together with pyoverdine, a second iron-chelating compound which was purified and identified by spectroscopy, HPLC and 1H-NMR to be salicylic acid. Mutants unable to synthesize pyoverdine overproduced this compound by a factor of 9-14. The biosynthesis of salicylic acid was under iron control; it was fully inhibited by 5 microM added iron in the growth medium. In contrast, salicylic acid of either bacterial or commercial origin facilitated labeled iron incorporation in iron-starved cells. Based on these two relationships observed with bacterial iron metabolism it is concluded that salicylic acid has a siderophore function for this strain.
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PMID:Iron metabolism in Pseudomonas: salicylic acid, a siderophore of Pseudomonas fluorescens CHAO. 129 72

Favourable mutations involving the two dehalogenases (DehI and DehII) of Pseudomonas putida PP3 and derivative strains containing the cloned gene for DehI (dehI) occurred in response to specific environmental conditions, namely: starvation conditions; the presence of dehalogenase substrates (halogenated alkanoic acids--HAAs) which were toxic to P. putida; and/or the presence of a potential growth substrate. Fluctuation tests showed that these mutations were environmentally directed by the presence of HAAs. The mutations were associated with complex DNA rearrangements involving the movement of dehI located on a transposon DEH. Some mutations resulted in switching off the expression of either one or both of the dehalogenases, events which were effective in protecting P. putida from toxic compounds in its growth environment. Other mutations partially restored P. putida's dehalogenating capability under conditions where toxic substrates were absent. Restoration of the capability to untilize HAAs was favoured when normal growth substrates were present in the environment.
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PMID:Environmentally directed mutations in the dehalogenase system of Pseudomonas putida strain PP3. 133 36

The oprO gene of Pseudomonas aeruginosa codes for a polyphosphate-specific porin and terminates 458 bp upstream of the start codon for the phosphate-specific porin OprP. OprO was found to be expressed only under phosphate-starvation conditions in both wild-type and oprP::Tn501 mutant P. aeruginosa strains. However, unlike the rest of the genes of the Pho regulon, including oprP, expression of oprO required cells to be in the stationary growth phase in addition to phosphate starvation. Wild-type P. aeruginosa cells were grown in fermentor culture under these conditions and fractionated by selective solubilization in octylpolyoxyethylene detergent solution. Solubilized OprO was separated from OprP by application to a Mono Q FPLC column and elution with a salt gradient and shown to be functionally identical to cloned OprO produced in Escherichia coli. DNA sequencing of oprO showed the gene product to be highly homologous to OprP, with 76% identity and 16% conserved substitutions. Most genes of the Pho regulon possess a modified -35 region called the Pho box. Two such elements, separated by 4 bp were found in oprO. DNA sequencing also revealed a second Pho box in the oprP gene with the same spacing.
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PMID:Polyphosphate-selective porin OprO of Pseudomonas aeruginosa: expression, purification and sequence. 140 71


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