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At least 667 records · Page 37Linked to original sources
PubMed2001

Carbon and char residue yields from rapid pyrolysis of kraft black liquor.

The yields of char residue, fixed carbon, and inorganic carbonate were measured for oxidized black liquor char residues produced in a laboratory laminar entrained-flow reactor (LEFR) at heating rates of 4000-13,000 degrees C/s. The char residue yields at the end of devolatilization thus obtained decreased nearly linearly with temperature, from 75% at 700 degrees C to 58% at 1100 degrees C. There were explainable differences in the char residue yields from the liquor used in this study and those used in other studies. Char residue yields seemed to depend mainly on the temperature to which the particles or droplets were exposed and were not very sensitive to heating rate. Fixed carbon yields behaved similarly to those of the char residue. The fixed carbon remaining at the end of devolatilization decreased from 67% at 700 degrees C to about 45% at 1100 degrees C. The carbonate content in black liquor changed very little before and after devolatilization.

Carbon↗
PubMed2002

Effect of the vesicular-arbuscular mycorrhizal (VAM) fungus Glomus fasciculatum on the essential oil yield related characters and nutrient acquisition in the crops of different cultivars of menthol mint (Mentha arvensis) under field conditions.

The effects of inoculation with vesicular-arbuscular mycorrhizal (VAM) fungus Glomusfasciculatum on the root colonization, growth, essential oil yield and nutrient acquisition of three cultivars of menthol mint (Mentha arvensis); Kalka, Shivalik and Gomti, were studied under field conditions. The VAM inoculation significantly increased the root colonization, plant height, fresh herbage and dry matter yield. oil content and oil yield as compared to non-inoculated cultivars. The effect of VAM inoculation on the root colonization, growth and yield of mint was more pronounced with the cv Shivalik than the cvs Kalka and Gomati, indicating Shivalik as a highly mycorrhizal dependent genotype. VAM inoculation significantly increased the uptake of N, P and K by shoot tissues of mint, but most markedly increased the uptake of P. The VAM-inoculated mint plants depleted the available N, P and K in the rhizosphere soil as compared to non-inoculated control plants, however the extent of nutrient depletion was greater for P than N and K. We conclude that the VAM inoculation could significantly increase the root colonization, growth, essential oil yield and nutrient acquisition of mint for obtaining economic production under field conditions.

Asteraceae↗
PubMed2004

Yield, mushroom size and time to production of Pleurotus cornucopiae (oyster mushroom) grown on switch grass substrate spawned and supplemented at various rates.

To find a cost effective alternative substrate, Pleurotus cornucopiae 608 (yellow basidiomata) was grown on: (1) chopped, pasteurized switch grass (Panicum virgatum, 99%) with 1% ground limestone and (2) a mixture of pasteurized cottonseed hulls (75% dry wt.), 24% chopped wheat straw, and 1% ground limestone (all ingredients wt./wt.). The substrates were spawned at various levels (2.5%, 3.75% or 5% wet wt., crop I) and non-supplemented or supplemented with commercial delayed release nutrient (Campbell's S-41) at various levels (0%, 1.5%, 3%, 4.5%, 6%, 7.5% and 9% dry wt., crop II). Maximum yield (weight of fresh mushrooms harvested at maturity) was obtained on cottonseed hull/wheat straw substrate at a 3.75-5% spawn level and 6% S-41 supplement. On switch grass substrate, increasing spawn levels and supplement levels stimulated yields in a linear fashion. However, maximum yields were only 46% or less for those of similar treatments on cottonseed hull/wheat straw substrate. Yields were three times higher on switch grass that was harvested after the grass had senesced (winter; beige color) compared to material that was harvested when the grass was green (summer; time of flowering). Additional physical processing of the material, such as milling, may improve yield potential of this material.

Agriculture↗
PubMed2002

Excitation functions of 85Rb(p,xn)(85m,g,83,82,81)Sr reactions up to 100 MeV: integral tests of cross section data, comparison of production routes of 83Sr and thick target yield of 82Sr.

The beta+ emitter 83Sr (T(1/2) = 32.4 h, Ebeta+ = 1.23 MeV, Ibeta+ = 24%) is a potentially useful radionuclide for therapy planning prior to the use of the beta+ emitter 89Sr (T(1/2) = 50.5 d). In order to investigate its production possibility, cross section measurements on the 85Rb(p,xn)-reactions, leading to the formation of the isotopes (85m,g)Sr, 83Sr, 82Sr and 81Sr, were carried out using the stacked-foil technique. In a few cases, the products were separated via high-performance liquid chromatography. For 82Sr, both gamma-ray and X-ray spectrometry were applied; in other cases only gamma-ray spectrometry was used. From the measured excitation functions, the expected yields were calculated. For the energy range Ep = 37 --> 30 MeV the 83Sr yield amounts to 160 MBq/microA h and the level of the 85gSr (T(1,2) = 64.9 d) and 82Sr (T(1/2) = 25.5 d) impurities to <0.25%. In integral tests involving yield measurements radiostrontium was chemically separated and its radioactivity determined. The experimental production data agreed within 10% with those deduced from the excitation functions. The results of the 85Rb(p,3n)83Sr reaction were compared with the data on the production of 83Sr via the 82Kr(3He,2n)-process. In the energy range E3Hc = 18 --> 10 MeV the theoretical yield of 83Sr amounts to 5 MBq/microA h and the 82Sr impurity to about 0.2%. The method of choice for the production of 83Sr is thus the 85Rb(p,3n)-process, provided a 40 MeV cyclotron is available. During this study some supplementary information on the yield and purity of 82Sr was also obtained.

Cyclotrons↗
PubMed1998

Yield measurements for the 11B(p,n)11C and the 10B(d,n)11C nuclear reactions.

The yields from the 11B(p,n)11C nuclear reactions have been measured over the energy range of 0-28.6 MeV. The yields from the 10B(d,n)11C nuclear reactions have been measured over the energy range of 0-21.5 MeV. Cross-section values were derived from the yield data. The yield measurements were carried out on sealed samples of boron powder isotopically enriched to greater than 93%. The target holders were constructed of aluminum and each contained 50 mg of boron powder to achieve high energy resolution, but with sufficient material to ensure accurate cross-section measurements. 11C yields were determined by decay-curve analysis. Our data show that at energies below 5 MeV, the 11B(p,n)11C nuclear reaction can be expected to produce 250 mCi of 11C (based on a 30 min irradiation at a beam current of 100 microA).

Aluminum↗
PubMed1998

Factors affecting the yield of cardiac valve allografts from living unrelated donors.

OBJECTIVE: Allografts are the valve of choice for fertile women, patients with infective endocarditis and those with small aortic roots. However, the supply of valves is problematic and widespread usage is restricted by limited availability. Allograft valves are available from cadaveric donors and from the explanted hearts of transplant recipients. Potentially, hearts from these patients could be an excellent source of usable aortic and pulmonary valves. However, little information is available on the suitability of such donors, the procurement rate of allograft valves from this source, or the factors that limit the yield of implantable valves from explanted hearts. METHOD: In order to examine some of these issues, we have carried out a retrospective study on the explanted hearts offered to the East Anglian Tissue Bank by Papworth hospital. Papworth hospital carries out approximately 90 heart and heart/lung transplants per year. Over a 2 year period, the tissue bank was offered 72 hearts from this programme. RESULTS: Of the 72 hearts offered, 58 were accepted for subsequent dissection and further examination. A total of 14 hearts were refused. The main reasons for refusal were extensive cardiectomy trauma (4 hearts) and abnormal valve morphology (four hearts). Of the 116 valves from those hearts accepted for dissection, 55 valves were rejected upon further examination. Reasons for rejection included: cardiectomy trauma (26 valves), abnormal morphology (22 valves), procurement/dissection trauma (7 valves). Of the 61 valves banked, four were subsequently rejected due to positive or incomplete microbiology. Procurement trauma fell to 0% in the last 12 months of the study but cardiectomy trauma remained constant and was related to previous cardiac surgery. Overall, the yield of implantable valves was 0.8 valves/donor. However, the yield showed considerable variation, from 1.0 valves/donor for donors diagnosed as cardiomyopathy to 0.5 valves/donor for donors with ischaemic heart disease who had undergone previous cardiac surgery. CONCLUSION: It is possible to predict the likely yield of explanted heart valves from different groups of heart transplant recipients, based on diagnosis and previous history. The yield of usable valves could be increased by avoidance of injury, both during cardiectomy and subsequent removal of the valves; this is achievable through appropriate training.

Adolescent↗
PubMed1976

Effect of feeding fat to dairy cows receiving a fat-deficient basal diet. I. Milk yield and composition.

The effects of supplementing a basal diet, in which the low level of fatty acids limited milk production, with soya oil, a palm oil/palmitic acid mixture and tallow, on the yield of milk and of its constituents, and on the composition of the milk, are reported. The yields of milk and milk fat were greatly increased by all the oil-supplemented diets; the mean daily yield of solids-not-fat (SNF) was also increased, but supplementation with soya oil caused the yield of crude protein (CP) to decrease, whereas the other fat-rich concentrate mixtures gave the same mean yield of protein as did the low-fat, control diet. All 3 oil-supplemented diets lowered the proportion of CP in the milk, but the SNF content was unchanged by any treatment. Dietary soya oil tended to lower the proportion of fat in the milk, whilst the palm oil/palmitic acid mixture raised it, with the tallow exerting no effect. The results are discussed in relation to previous work in which these dietary oils have been used, but in which the intake of fatty acids from the control diets did not limit milk production to the extent reported here.

Animals↗
PubMed1984

Projection of lactation milk yield from part records in crossbred dairy cows.

First lactation records of a total of 242 Jersey (JH), Brown Swiss (BH) and Holstein-Friesian (FH) halfbreeds from Hariana cows were studied for projecting 300 d milk yield from 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38 and 40 weeks' milk yield. The correlation coefficients between 300 d milk yield and part records ranged from 0.84 to 0.9 in the JH, 0.80 to 0.90 in the BH and 0.72 to 0.86 in the FH groups. Prediction equations and standard errors of estimation for prediction of 300 d milk yield for an individual animal are presented. It is suggested that part records up to 16, 22 and 22 weeks may be used for projecting 300 d yield with sufficient accuracy in the JH, BH and FH groups respectively.

Animals↗
PubMed2002

Effect of frequency of milking on yield, composition and processing quality of milk.

The objective was to determine the effect of once-daily milking (ODM) and omitting one evening milking each week (13TWM), in late lactation on milk production, composition and processability. Seventy-two cows were assigned to three treatments (ODM, 13TWM and twice-daily milking [TDM]) from 4 October to 12 December. Cows were on average 218 d into lactation at the start of the trial, and all cows were managed similarly throughout the trial. Milk yields and gross milk composition of cows on all treatments were measured, and milk samples for detailed compositional and processability analysis were collected from TDM and ODM treatments at two consecutive milkings and at one milking each week, respectively. Milk yield was significantly reduced (P < 0.001) and milk fat and protein concentrations were increased (P < 0.01) with ODM compared with TDM. Milk yield and fat and protein concentrations of milk from TDM and 13TWM herds were similar. Casein concentrations in ODM and TDM milks were similar, but ODM milk had a higher (P < 0.05) whey protein content. Somatic cell count of ODM and TDM milks was similar. Rennet coagulation time (RCT) and curd firmness (A60) of milk were not affected by milking frequency. However, rate of curd aggregation (K20) of ODM milk was reduced (P < 0.05) compared with that of TDM milk. Plasmin activity in ODM milk was numerically higher than in TDM milk, but the effect was not significant. ODM milk had higher NAGase activity than TDM milk (P < 0.01). In conclusion, once daily milking reduced milk yield by 29% and did not adversely affect the processability of milk. Moreover, one evening milking per week could be eliminated without adverse effects on milk yield or composition.

Acetylglucosaminidase↗
PubMed2005

Effect of different milking routines on milking-related release of the hormones oxytocin, prolactin and cortisol, and on milk yield and milking performance in Murrah buffaloes.

Milking-related release of oxytocin, prolactin, and cortisol was studied following three premilking treatments. Six Murrah buffaloes were treated with direct application of milking cluster (O), a 1-min pre-stimulation (M), and combined feeding and pre-stimulation (MF). Machine milk yield, stripping yield and milk composition were recorded. Milk ejection occurred significantly earlier with MF than M and O (P<0.05; 2.50, 5.10 and 6.33 min, respectively). In all treatments, milk ejection occurred with small increases >3-5 ng/l in oxytocin concentration. Increase in oxytocin concentration over a threshold level and milk ejection occurred simultaneously and were closely correlated (r=0.83, P<0.05). There was a positive correlation between total time oxytocin concentration remained elevated over threshold levels and machine yield (r=0.86, P<0.05). For treatment O, milk ejection was inhibited during machine milking, while a marked increase in oxytocin occurred during hand stripping (6 and 16 ng/l, respectively). For treatment M, mean oxytocin concentrations remained unchanged during prestimulation but increased during subsequent machine milking and hand stripping (6.38, 18.06 and 12.36 ng/l, respectively). For treatment MF, although there was a 3.6-fold increase during pre-stimulation, oxytocin increased by 10-fold and 3-fold during machine milking and hand stripping, and was significant for machine milking (P<0.05, 17.32, 47.86, 18.13 ng/l, respectively). Milk-ejection-related cortisol release was visible only in treatment MF. For treatments O and M, prolactin concentration increased prior to the increase in oxytocin. The stripping yield was higher, and fat content in the stripping yield significantly lower, for treatment O indicating incomplete milking. Thus buffaloes are easily disturbed even by small changes in milking routines.

Animals↗
PubMed2006

Effects of genetic polymorphisms at the growth hormone gene on milk yield in Serra da Estrela sheep.

The five exons and the 5' and 3'-untranslated regions (5'-UTR and 3'-UTR) of the oGH gene were screened for mutations using PCR-single strand conformation polymorphism (PCR-SSCP) procedures in 523 Serra da Estrela ewes and were found to be highly polymorphic. The region extending across and between the GH2-N and GH2-Z copies was sequenced allowing the design of primers for the specific PCR amplification of each copy. These were cloned and sequenced in 20 animals representative of all SSCP patterns. The corresponding genotypes were established for each copy following nucleotide sequencing of SSCP alleles. Twenty-four polymorphic sites were found at the GH2-N (or GH1) and fourteen at the GH2-Z copies. Eight amino acid substitutions were predicted at the GH2-N and six at the GH2-Z copies. Milk yield adjusted to 150 lactation days was analysed for the genotype of each oGH gene copy taken separately or together (associated genotypes) by restricted maximum likelihood (REML) through a univariate best linear unbiased prediction (BLUP) animal model with repeated measures. Significant associations between genotypes and milk yield were observed. Within GH2-N genotypes there was a milk yield differential of 21.4+/-0.2 l/150 d between the most (N7) and the least (N5) productive ones. Within GH2-Z genotypes there was a differential of 21.6+/-0.2 l/150 d between the most (Z8) and the least (Z1) productive ones. The effect of associated GH2-N and GH2-Z genotypes revealed a differential of 39.6+/-0.3 l/150 d between the most (N1+Z7) and the least (N3+Z2) productive associated genotypes. The results show that GH2-N and GH2-Z genotypes significantly affect milk yield in Serra da Estrela ewes. Moreover, the apparent joint effect of GH2-N and GH2-Z genotype could improve milk yield in 25% as compared with the mean milk production of the analysed population.

3' Untranslated Regions↗
PubMed1997

Effect of unilateral once or twice daily milking of cows on milk yield and udder characteristics in early and late lactation.

Twelve multiparous British Friesian cows in early (40 +/- 23 d in milk; n = 6) or late (216 +/- 17 d in milk; n = 6) lactation were used to study the effects of milking frequency on yield, udder volume and milk storage within the udder. After a 2 week control period of twice daily milking, diagonally opposed udder halves within a cow were milked once or twice daily for 3 weeks. Milk yield was 28-38% lower from the halves that were milked once daily than from halves that were milked twice daily. The loss of milk yield, expressed as a decrease in the relative milk yield quotient (an index that accounts for pretreatment differences), was greater for cows in early than in late lactation (0.59 v. 0.68). Empty udder-half volume was not decreased by once daily milking, suggesting that no cell loss occurred. Instead, once daily milking reduced the secretion efficiency (units of milk per unit of empty udder-half volume) by 46 and 27% respectively in early and late lactation; thus, at least part of the loss was due to reduced metabolic activity of the mammary epithelium. There were positive correlations between the relative milk yield quotient and the proportion (r = 0.804) or volume (r = 0.644) of cisternal milk in the glands that were milked once daily. These results confirm that, during extended milking intervals, milk loss was smallest for cows that stored a larger proportion of milk in the gland cistern.

Animals↗
PubMed1999

Effects of calcium soaps of rapeseed fatty acids and protected methionine on milk yield and composition in dairy cows.

The objective of this study was to determine the effects of supplementing the diets of dairy cows with Ca soaps of rapeseed fatty acids (CSRFA) and rumen-protected (RP) methionine on their milk yield and composition, including milk protein fractions and fatty acids. Twelve Polish Red Lowland cows were used in a complete balanced two period changeover experiment. The four treatment diets were a control consisting of a total mixed ration of grass silage and concentrates, and the total mixed ration supplemented with RP methionine, CSRFA or RP methionine plus CSRFA. Dry matter intake was not affected by diet. Milk yield increased when cows were given the diet with CSRFA, but supplementation of diets with RP methionine did not affect milk yield. Milk protein content, but not milk protein yield, decreased when CSRFA was given. The addition of RP methionine to the control diet and the CSRFA diet produced similar increases in the milk protein content. Supplementation of the diet with CSRFA significantly changed the milk fatty acid profile: the proportions of 10:0, 12:0, 14:0, 15:0 and 16:0 in milk fat decreased, but those of 18:0 and cis-18:1 increased. We conclude that CSRFA can be used in practical dairy diets to increase milk yield and manipulate its fatty acid composition.

Animals↗
PubMed1993

Continuous-wave quantum yields of various cobalamins are influenced by competition between geminate recombination and cage escape.

Quantum yields of photolysis of the cobalt-carbon bond for three cobalamin compounds were measured with a continuous-wave laser at 442 nm under both aerobic and anaerobic conditions. Aerobically, the initial homolysis product, Co(II) cobalamin, is trapped by oxygen to form aquocobalamin. Use of an excess of the radical trapping reagent 2,2,6,6-tetramethyl-1-piperidinyloxyl, under anaerobic conditions, scavenges the carbon radical and allows detection of the cobalt(II) photoproduct. Quantum yields measured under anaerobic conditions for 5'-deoxyadenosylcobalamin (phi (Co-C alpha),442 = 0.20 +/- 0.03) and methylcobalamin (phi (Co-C alpha),442 = 0.35 +/- 0.03) are in agreement with the values obtained under aerobic conditions (phi (Co-C alpha),442 = 0.19 +/- 0.04 and phi (Co-C alpha),442 = 0.36 +/- 0.04, respectively). Additionally, the quantum yield values for 5'-deoxyadenosylcobalamin and its base-off derivative (phi (Co-C alpha),442 = 0.045 +/- 0.015) match those obtained on a nanosecond time scale [Chen, E., & Chance, M. R. (1990) J. Biol. Chem. 256, 12987-12994]. A comparison of quantum yields obtained anaerobically for 5'-deoxyadenosylcobalamin and methylcobalamin in H2O versus ethylene glycol shows a 4-fold decrease for the former cobalamin and no change for the latter. These quantum yields are evaluated in terms of time-independent radical separation distances.

Aerobiosis↗
PubMed1993

Oxidative refolding of insulin-like growth factor 1 yields two products of similar thermodynamic stability: a bifurcating protein-folding pathway.

Can one protein sequence encode two structures? Oxidative folding of human insulin-like growth factor 1 (IGF-1), a globular protein of 70 residues, is shown to yield two products of similar thermodynamic stability. This observation is of particular interest in light of the recent demonstration that two of the three disulfide bonds in native IGF-1 rearrange in the presence of dithiothreitol [Hober, S., et al. (1992) Biochemistry 31, 1749-1756]. Kinetics of the IGF-1 folding pathway were monitored by high-performance liquid chromatography (rp-HPLC). Disulfide-pairing schemes of intermediates and products were established by peptide mapping. Two disulfide isomers were obtained as products: one with native insulin-like pairing [6-48; 18-61; 47-52] (designated native IGF-1; 60% yield) and the other with alternative pairing [6-47; 18-61; 48-52] (designated IGF-swap; 40% yield). The predominant early intermediate contains the single disulfide 18-61, which is shared in common by the two products. Relative yields of native IGF-1 and IGF-swap are independent of protein concentration under dilute conditions. In the absence of an added thiol reagent, each isomer is stable indefinitely at neutral pH; in the presence of an added thiol reagent, the two isomers interconvert with an Arrhenius activation barrier of 12 kcal/mol. Interconversion does not require complete reduction and yields the same ratio of products as initial folding, demonstrating thermodynamic control. Spectroscopic studies using circular dichroism (CD), infrared spectroscopy (FTIR), two-dimensional 1H-NMR (2D-NMR), and photochemical dynamic nuclear polarization (photo-CIDNP) suggest that IGF-1 and IGF-swap adopt similar secondary structures but distinct tertiary folds. Implications of these observations for understanding the topology of protein-folding pathways are discussed.

Amino Acid Sequence↗
PubMed2002

Effects of chemical modification, tropomyosin, and myosin subfragment 1 on the yield strength and critical concentration of F-actin.

The effects of coupling with tetramethylrhodamine-5-iodoacetamide and of the decoration with tropomyosin and with myosin subfragment 1 on the elastic properties of F-actin filament are investigated. At 22 degrees C, in 15 mM orthophosphate and 3 mM MgCl2, tetramethylrhodamine F-actin displays a yield strength of 3.69 +/- 0.213 pN and an elastic modulus by stretching of 0.91 MPa. Decoration with tropomyosin increases the yield strength of tetramethylrhodamine F-actin to 10.51 +/- 0.24 pN and the elastic modulus by stretching to 23-75 MPa. Mixtures of myosin subfragment 1 and tetramethylrhodamine F-actin at the 0.2:1, 0.4:1, 0.6:1, 0.8:1, and 1:1 molar ratios are also studied. Both yield strength and the elastic modulus by stretching are found to increase progressively with the ratio. At the 1:1 molar ratio, the yield strength is 15.81 +/- 0.26 pN and the elastic modulus by stretching is 13.45 to 40 MPa. Decoration of tetramethylrhodamine F-actin with both tropomyosin and myosin subfragment 1, at the 1:1 molar ratio with the actin monomer, produces filaments with an yield strength of 22.3 +/- 0.48 pN.

Actins↗
PubMedDate not supplied

Effect of protease inhibitors on yield of HSV-1-based viral vectors.

The ability to obtain high titer replication-defective herpes simplex virus (HSV) recombinant vectors will dramatically affect their use in gene therapy clinical trials. A variety of techniques and reagents have been employed to increase the overall yield of the vector. The effects of protease inhibitors on the yield of an HSV-1-based viral vector were examined. Experiments were conducted using a commercial protease inhibitor cocktail typically used in mammalian cell culture for protein production. Contrary to our expectation for enhanced vector yield, the results showed a dramatic reduction in vector yield. Moreover, it was found that AEBSF is the only component in the protease cocktail responsible for the low vector yield. On the basis of our hypothesis regarding the mode of action of AEBSF, we suggest that it should not be included in protease inhibitor cocktails designed for use in cultures aimed at production of viral vectors derived from HSV-1 or possibly several other vectors.

Culture Media↗
PubMedDate not supplied

Altered glucose transport and shikimate pathway product yields in E. coli.

Different glucose transport systems are examined for their impact on phosphoenolpyruvate availability as reflected by the yields of 3-dehydroshikimic acid and byproducts 3-deoxy-d-arabino-heptulosonic acid, 3-dehydroquinic acid, and gallic acid synthesized by Escherichia coli from glucose. 3-Dehydroshikimic acid is an advanced shikimate pathway intermediate in the syntheses of a spectrum of commodity, pseudocommodity, and fine chemicals. All constructs carried plasmid aroF(FBR) and tktA inserts encoding, respectively, a feedback-insensitive isozyme of 3-deoxy-d-arabino-heptulosonic acid 7-phosphate synthase and transketolase. Reliance on the native E. coli phosphoenolpyruvate:carbohydrate phosphotransferase system for glucose transport led in 48 h to the synthesis of 3-dehydroshikimic acid (49 g/L) and shikimate pathway byproducts in a total yield of 33% (mol/mol). Use of heterologously expressed Zymomonas mobilis glf-encoded glucose facilitator and glk-encoded glucokinase resulted in the synthesis in 48 h of 3-dehydroshikimic acid (60 g/L) and shikimate pathway byproducts in a total yield of 41% (mol/mol). Recruitment of native E. coli galP-encoded galactose permease for glucose transport required 60 h to synthesize 3-dehydroshikimic acid (60 g/L) and shikimate pathway byproducts in a total yield of 43% (mol/mol). Direct comparison of the impact of altered glucose transport on the yields of shikimate pathway products synthesized by E. coli has been previously hampered by different experimental designs and culturing conditions. In this study, the same product and byproduct mixture synthesized by E. coli constructs derived from the same progenitor strain is used to compare strategies for increasing phosphoenolpyruvate availability. Constructs are cultured under the same set of fermentor-controlled conditions.

3-Deoxy-7-Phosphoheptulonate Synthase↗