Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q9UIJ5 (Rec)
 58,342 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ninety-six strains of Salmonella senftenberg, isolated between 1984 and 1986 from different parts of England and Wales, were tested for their biochemical reactions and biotyped according to the method of Duguid and others (1975). Nine biogroups were identified on the basis of their metabolism of L-tartrate, D-tartrate, Bitter's xylose and Stern's glycerol. In addition, fumaric, oxalic, succinic, glutaric, malonic, maleic, L-malic, L-aspartic, lactic and formic acids were used but did not increase the discrimination. Three biogroups (7, 2 and 5) accounted for 79 per cent of the cultures examined.
Vet Rec 1991 Dec 14
PMID:Differentiation of Salmonella senftenberg into biogroups. 178 18

Two recombinant plasmids, pSNL1 and pSNL2, carrying structural genes for L-arabinose utilization were isolated from a Bacillus subtilis gene library. Both plasmids complemented araD mutations in a Rec- B. subtilis strain and in Escherichia coli. Moreover, pSNL1 also complemented araB mutations in both species and efficiently transformed araA Rec+ B. subtilis strains to Ara+. Detailed physical mapping of both plasmids in addition to transformation experiments involving defined restriction fragments from the pSNL1 insert unambiguously determined the gene order to be araD, araB, and araA, an order different from that found in E. coli.
 ...
PMID:Cloning and characterization of araA, araB, and araD, the structural genes for L-arabinose utilization in Bacillus subtilis. 250 Apr 24

When arabinose-grown Escherichia coli B/r is ultraviolet (UV) irradiated in the logarithmic phase of growth, the dose inactivation curve for both colony formation and deoxyribonucleic acid (DNA) synthesis (based on the relative rates of synthesis) is exponential in nature. When protein synthesis is inhibited before UV-irradiation, both inactivation curves have a large shoulder. Pre-irradiation inhibition of protein synthesis increases considerably the colony-forming ability of a UV-irradiated Hcr(-) and Rec(-) strain of E. coli B/r. However, with the repair-deficient strains, both the shoulder and slope of the survival curve are affected. We investigated the effect of UV irradiation on DNA synthesis in Hcr(-) bacteria and found that pre-irradiation inhibition of protein synthesis increases UV resistance of DNA replication in this strain also. The results suggest that inhibition of protein synthesis before irradiation increases UV resistance in E. coli B/r by a mechanism which is independent of both the excision and recombination repair systems.
 ...
PMID:Relation between survival and deoxyribonucleic acid replication in ultraviolet-irradiated resistant and sensitive strains of Escherichia coli B-r. 457 Jul 72

Exocrine pancreatic insufficiency in the dog has been assessed by the oral administration of the synthetic peptide N-benzoyl-L-tyrosyl-p-aminobenzoic acid (BT-PABA), a specific substrate for pancreatic chymotrypsin. The subsequent assay of PABA in either the plasma or the urine clearly differentiated control animals from those with exocrine pancreatic insufficiency (EPI), the results being unaffected by combination of this pancreatic function with a xylose absorption test. Possible interference with the specificity of the peptide test for the diagnosis of EPI was examined in six animals with small intestinal disease. In a group of four animals, with features resembling chronic tropical sprue in man, the results were comparable to those of the control group. In the fifth case, however, the results were indistinguishable from those of the EPI group, the estimation of sodium PABA absorption and the assay of proteolytic activity in the duodenal juice demonstrating that this was due to defective hydrolysis of the peptide. In the sixth case, diffuse intestinal lymphosarcoma and a marked villous atrophy were associated with an apparent reduction in the absorption of sodium PABA. However, although the plasma PABA concentrations following oral BT-PABA were subnormal, they were distinctly higher than those of the EPI group. These findings suggest that small intestinal abnormalities do not affect PABA absorption sufficiently to interfere with the specificity of the peptide test for the detection of severe EPI in the dog. This insufficiency may occasionally be secondary to small intestinal disease.
Vet Rec 1981 Apr 04
PMID:Specificity of the BT-PABA test for the diagnosis of exocrine pancreatic insufficiency in the dog. 697 20

Breath hydrogen excretion over a period of three hours was measured to evaluate carbohydrate malassimilation in healthy cats treated orally with antibiotics. Both an absorbable carbohydrate (xylose) and a non-absorbable carbohydrate (lactulose) were administered during the tests to evaluate the changes in the intestinal mucosa and the population of bacteria within the intestinal lumen. Overall, the effects of oxytetracycline and metronidazole on breath hydrogen excretion were not significantly different. However, the treatment effect with an antibiotic did significantly change breath hydrogen excretion after xylose administration (P < 0.05) within groups. Similarly, with each antibiotic, breath hydrogen excretion was affected significantly (P < 0.001) by the time after the administration of the carbohydrate. Treatment with each antibiotic also interacted significantly with this time effect (P < 0.05) within groups. After lactulose administration, there was a trend within groups for the type of antibiotic to interact with the treatment effect on breath hydrogen excretion (P = 0.09). After oxytetracycline treatment, more hydrogen was exhaled during the first 120 minutes after lactulose administration than in the pre-antibiotic test, whereas after metronidazole treatment, less hydrogen was exhaled between 60 and 180 minutes after lactulose, administration. After treatment with either oxytetracycline or metronidazole, more hydrogen was exhaled after xylose administration. Obligate anaerobes could be isolated from samples of small intestinal fluid obtained endoscopically after oxytetracycline treatment, but they could not be isolated after treatment with metronidazole.
Vet Rec 1996 Jun 29
PMID:Breath hydrogen excretion by healthy cats after oral administration of oxytetracycline and metronidazole. 881 57

Recombinant Zymomonas mobilis CP4:pZB5 was grown with pH control in batch and continuous modes with either glucose or xylose as the sole carbon and energy source. In batch cultures in which the ratio of the final cell mass concentration to the amount of sugar in the medium was constant (i.e., under conditions that promote "coupled growth"), maximum specific rates of glucose and xylose consumption were 8.5 and 2.1 g/(g of cell.h), respectively; maximum specific rates of ethanol production for glucose and xylose were 4.1 and 1.0 g/(g of cell.h), respectively; and average growth yields from glucose and xylose were 0.055 and 0.034 g of dry cell mass (DCM)/g of sugar, respectively. The corresponding value of YATP for glucose and xylose was 9.9 and 5.1 g of DCM/mol of ATP, respectively. YATP for the wild-type culture CP4 with glucose was 10.4 g of DCM/mol of ATP. For single substrate chemostat cultures in which the growth rate was varied as the dilution rate (D), the maximum or "true" growth yield (max Yx/s) was calculated from Pirt plots as the inverse of the slope of the best-fit linear regression for the specific sugar utilization rate as a function of D, and the "maintenance coefficient" (m) was determined as the y-axis intercept. For xylose, values of max Yx/s and m were 0.0417 g of DCM/g of xylose (YATP = 6.25) and 0.04 g of xylose/(g of cell.h), respectively. However, with glucose there was an observed deviation from linearity, and the data in the Pirt plot was best fit with a second-order polynomial in D. At D > 0.1/h, YATP = 8.71 and m = 2.05 g of glu/(g of cell.h) whereas at D < 0.1/h, YATP = 4.9 g of DCM/mol of ATP and m = 0.04 g of glu/(g of cell.h). This observation provides evidence to question the validity of the unstructured growth model and the assumption that Pirt's maintenance coefficient is a constant that is independent of the growth rate. Collectively, these observations with individual sugars and the values assigned to various growth and fermentation parameters will be useful in the development of models to predict the behavior of rec Zm in mixed substrate fermentations of the type associated with biomass-to-ethanol processes.
 ...
PMID:Comparative energetics of glucose and xylose metabolism in recombinant Zymomonas mobilis. 1084 96

This study examined the continuous cofermentation performance characteristics of a dilute-acid "prehydrolysate-adapted" recombinant Zymomonas 39676:pZB4L and builds on the pH-stat batch fermentations with this recombinant that we reported on last year. Substitution of yeast extract by 1% (w/v) corn steep liquor (CSL) (50% solids) and Mg (2 mM) did not alter the cofermentation performance. Using declared assumptions, the cost of using CSL and Mg was estimated to be 12.5 cents/gal of ethanol with a possibility of 50% cost reduction using fourfold less CSL with 0.1% diammonium phosphate. Because of competition for a common sugar transporter that exhibits a higher affinity for glucose, utilization of glucose was complete whereas xylose was always present in the chemostat effluent. The ethanol yield, based on sugar used, was 94% of theoretical maximum. Altering the sugar ratio of the synthetic dilute acid hardwood prehydrolysate did not appear to significantly change the pattern of xylose utilization. Using a criterion of 80% sugar utilization for determining the maximum dilution rate (Dmax), changing the composition of the feed from 4% xylose to 3%, and simultaneously increasing the glucose from 0.8 to 1.8% shifted Dmax from 0.07 to 0.08/h. With equal amounts of both sugars (2.5%), Dmax was 0.07/h. By comparison to a similar investigation with rec Zm CP4:pZB5 with a 4% equal mixture of xylose and glucose, we observed that at pH 5.0, the Dmax was 0.064/h and shifted to 0.084/h at pH 5.75. At a level of 0.4% (w/v) acetic acid in the CSL-based medium with 3% xylose and 1.8% glucose at pH 5.75, the Dmax for the adapted recombinant shifted from 0.08 to 0.048/h, and the corresponding maximum volumetric ethanol productivity decreased 45%, from 1.52 to 0.84 g/(L.h). Under these conditions of continuous culture, linear regression of a Pirt plot of the specific rate of sugar utilization vs D showed that 4 g/L of acetic acid did not affect the maximum growth yield (0.030 g dry cell mass/g sugar), but did increase the maintenance coefficient twofold, from 0.46 to 1.0 g of sugar/(g of cell.h).
 ...
PMID:Continuous fermentation studies with xylos-utilizing recombinant Zymomonas mobilis. 1084 97

In pH-controlled batch fermentations with pure sugar synthetic hardwood hemicellulose (1% [w/v] glucose and 4% xylose) and corn stover hydrolysate (8% glucose and 3.5% xylose) lacking acetic acid, the xylose-utilizing, tetracycline (Tc)-sensitive, genomically integrated variant of Zymomonas mobilis ATCC 39676 (designated strain C25) exhibited growth and fermentation performance that was inferior to National Renewable Energy Laboratory's first-generation, Tc-resistant, plasmid-bearing Zymomonas recombinants. With C25, xylose fermentation following glucose exhaustion was markedly slower, and the ethanol yield (based on sugars consumed) was lower, owing primarily to an increase in lactic acid formation. There was an apparent increased sensitivity to acetic acid inhibition with C25 compared with recombinants 39676:pZB4L, CP4:pZB5, and ZM4:pZB5. However, strain C25 performed well in continuous fermentation with nutrient-rich synthetic corn stover medium over the dilution range 0.03-0.06/h, with a maximum process ethanol yield at D = 0.03/h of 0.46 g/g and a maximum ethanol productivity of 3 g/(L x h). With 0.35% (w/v) acetic acid in the medium, the process yield at D = 0.04/h dropped to 0.32 g/g, and the maximum productivity decreased by 50% to 1.5 g/(L x h). Under the same operating conditions, rec Zm ZM4:pZB5 performed better; however, the medium contained 20 mg/L of Tc to constantly maintain selective pressure. The absence of any need for antibiotics and antibiotic resistance genes makes the chromosomal integrant C25 more compatible with current regulatory specifications for biocatalysts in large-scale commercial operations.
 ...
PMID:Fermentation performance assessment of a genomically integrated xylose-utilizing recombinant of Zymomonas mobilis 39676. 1196 41

Iogen Corporation of Ottawa, Canada, has recently built a 50 t/d biomass-to-ethanol demonstration plant adjacent to its enzyme production facility. Iogen has partnered with the University of Toronto to test the C6/C5 cofermentation performance characteristics of National Renewable Energy Laboratory's metabolically engineered Zymomonas mobilis using its biomass hydrolysates. In this study, the biomass feedstock was an agricultural waste, namely oat hulls, which was hydrolyzed in a proprietary two-stage process involving pretreatment with dilute sulfuric acid at 200-250 degrees C, followed by cellulase hydrolysis. The oat hull hydrolysate (OHH) contained glucose, xylose, and arabinose in a mass ratio of about 8:3:0.5. Fermentation media, prepared from diluted hydrolysate, were nutritionally amended with 2.5 mL/L of corn steep liquor (50% solids) and 1.2 g/L of diammonium phosphate. The estimated cost for large-scale ethanol production using this minimal level of nutrient supplementation was 4.4cents/gal of ethanol. This work examined the growth and fermentation performance of xylose-utilizing, tetracycline-resistant, plasmid-bearing, patented, recombinant Z. mobilis cultures: CP4:pZB5, ZM4:pZB5, 39676:pZB4L, and a hardwood prehydrolysate-adapted variant of 39676:pZB4L (designated as the "adapted" strain). In pH-stat batch fermentations with unconditioned OHH containing 6% (w/v) glucose, 3% xylose, and 0.75% acetic acid, rec Zm ZM4:pZB5 gave the best performance with a fermentation time of 30 h, followed by CP4:pZB5 at 48 h, with corresponding volumetric productivities of 1.4 and 0.89 g/ (L x h), respectively. Based on the available glucose and xylose, the process ethanol yield for both strains was 0.47 g/g (92% conversion efficiency). At 48 h, the process yield for rec Zm 39676:pZB4L and the adapted strain was 0.32 and 0.34 g/g, respectively. None of the test strains was able to ferment arabinose. Acetic acid tolerance appeared to be a major determining factor in cofermentation performance.
 ...
PMID:Comparative ethanol productivities of different Zymomonas recombinants fermenting oat hull hydrolysate. 1196 42

IOGEN Corporation of Ottawa, Canada, has recently built a 40t/d biomass-to-ethanol demonstration plant adjacent to its enzyme production facility. It has partnered with the University of Toronto to test the C6/C5 cofermenta-tion performance characteristics of the National Renewable Energy Labora-tory's metabolically engineered Zymomonas mobilis using various biomass hydrolysates. IOGEN's feedstocks are primarily agricultural wastes such as corn stover and wheat straw. Integrated recombinant Z. mobilis strain AX101 grows on D-xylose and/or L-arabinose as the sole carbon/energy sources and ferments these pentose sugars to ethanol in high yield. Strain AX101 lacks the tetracycline resistance gene that was a common feature of other recombinant Zm constructs. Genomic integration provides reliable cofermentation performance in the absence of antibiotics, another characteristic making strain AX101 attractive for industrial cellulosic ethanol production. In this work, IOGEN's biomass hydrolysate was simulated by a pure sugar medium containing 6% (w/v) glucose, 3% xylose, and 0.35% arabinose. At a level of 3 g/L (dry solids), corn steep liquor with inorganic nitrogen (0.8 g/L of ammonium chloride or 1.2 g/L of diammonium phosphate) was a cost-effective nutritional supplement. In the absence of acetic acid, the maximum volumetric ethanol productivity of a continuous fermentation at pH 5.0 was 3.54 g/L x h. During prolonged continuous fermentation, the efficiency of sugar-to-ethanol conversion (based on total sugar load) was maintained at >85%. At a level of 0.25% (w/v) acetic acid, the productivity decreased to 1.17 g/L x h at pH 5.5. Unlike integrated, xylose-utilizing rec Zm strain C25, strain AX101 produces less lactic acid as byproduct, owing to the fact that the Escherichia coli arabinose genes are inserted into a region of the host chromosome tentatively assigned to the gene for D-lactic acid dehydrogenase. In pH-controlled batch fermentations with sugar mixtures, the order of sugar exhaustion from the medium was glucose followed by xylose and arabinose. Both the total sugar load and the sugar ratio were shown to be important determinants for efficient cofermentation. Ethanol at a level of 3% (w/v) was implicated as both inhibitory to pentose fermentation and as a potentiator of acetic acid inhibition of pentose fermentation at pH 5.5. The effect of ethanol may have been underestimated in other assessments of acetic acid sensitivity. This work underscores the importance of employing similar assay conditions in making comparative assessments of biocatalyst fermentation performance.
 ...
PMID:Performance testing of Zymomonas mobilis metabolically engineered for cofermentation of glucose, xylose, and arabinose. 1201 70


1 2 Next >>