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Adekolurejo OO, McDermott K, Greathead HMR, Miller HM, Mackie AR, Boesch C. Effect of Red-Beetroot-Supplemented Diet on Gut Microbiota Composition and Metabolite Profile of Weaned Pigs-A Pilot Study. Animals (Basel) 2023; 13:2196. [PMID: 37443994 DOI: 10.3390/ani13132196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 06/20/2023] [Accepted: 06/27/2023] [Indexed: 07/15/2023] Open
Abstract
Red beetroot is a well-recognized and established source of bioactive compounds (e.g., betalains and polyphenols) with anti-inflammatory and antimicrobial properties. It is proposed as a potential alternative to zinc oxide with a focus on gut microbiota modulation and metabolite production. In this study, weaned pigs aged 28 days were fed either a control diet, a diet supplemented with zinc oxide (3000 mg/kg), or 2% and 4% pulverized whole red beetroot (CON, ZNO, RB2, and RB4; respectively) for 14 days. After pigs were euthanized, blood and digesta samples were collected for microbial composition and metabolite analyses. The results showed that the diet supplemented with red beetroot at 2% improved the gut microbial richness relative to other diets but marginally influenced the cecal microbial diversity compared to a zinc-oxide-supplemented diet. A further increase in red beetroot levels (4%-RB4) led to loss in cecal diversity and decreased short chain fatty acids and secondary bile acid concentrations. Also, an increased Proteobacteria abundance, presumably due to increased lactate/lactic-acid-producing bacteria was observed. In summary, red beetroot contains several components conceived to improve the gut microbiota and metabolite output of weaned pigs. Future studies investigating individual components of red beetroot will better elucidate their contributions to gut microbiota modulation and pig health.
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Affiliation(s)
- Opeyemi O Adekolurejo
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, UK
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Katie McDermott
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | | | - Helen M Miller
- Faculty of Biological Sciences, University of Leeds, Leeds LS2 9JT, UK
| | - Alan R Mackie
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, UK
| | - Christine Boesch
- School of Food Science and Nutrition, University of Leeds, Leeds LS2 9JT, UK
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Laird S, Kühn I, Bedford MR, Whitfield H, Miller HM. Sampling duration and freezing temperature influence the analysed gastric inositol phosphate composition of pigs fed diets with different levels of phytase. ACTA ACUST UNITED AC 2019; 5:196-201. [PMID: 31193977 PMCID: PMC6544748 DOI: 10.1016/j.aninu.2018.12.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 12/06/2018] [Accepted: 12/28/2018] [Indexed: 11/30/2022]
Abstract
This experiment was conducted to determine the effects of time and freezing temperature during sampling on gastric phytate (myo-inositol [MYO] hexakisphosphate [InsP6]), lower inositol phosphates (InsP2–5) and MYO concentrations in pigs fed diets containing different levels of phytase. Forty pigs were fed 1 of 4 wheat-barley diets on an ad libitum basis for 28 d. The diets comprised a nutritionally adequate positive control (PC), a similar diet but with Ca and P reduced by 1.6 and 1.24 g/kg, respectively (NC), and the NC supplemented with 500 (NC + 500) or 2,000 (NC + 2000) FTU phytase/kg. At the end of the experiment, chyme were collected from the stomach, thoroughly mixed and 2 subsamples (30 mL) were frozen immediately: one snap-frozen at −79 °C and the other at −20 °C. The remaining chyme were left to sit at room temperature (20 °C) and further subsamples were collected and frozen as above at 5, 10 and 15 min from the point of mixing. There were linear reductions in gastric InsP6 concentration over time during sampling (P < 0.001), irrespective of diet or freezing temperature. Moreover, InsP6 concentration was influenced by a diet × freezing temperature interaction (P < 0.05), with less InsP6 measured in chyme frozen at −20 °C than at −79 °C; however, this difference was greater in the control diets than the phytase supplemented diets. Freezing chyme at −79 °C recovered more ∑InsP2–5 + MYO than freezing at −20 °C in pigs fed phytase supplemented diets; however, this difference was not apparent in the diets without phytase (diet × freezing temperature, P < 0.01). It can be concluded that significant phytate hydrolysis occurs in the gastric chyme of pigs during sampling and processing, irrespective of supplementary phytase activity. Therefore, to minimise post-slaughter phytate degradation and changes in the gastric inositol phosphate profile, chyme should be snap-frozen immediately after collection.
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Affiliation(s)
- Steven Laird
- Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
| | - Imke Kühn
- AB Vista, Marlborough, SN8 4AN, United Kingdom
| | | | - Hayley Whitfield
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, United Kingdom
| | - Helen M Miller
- Faculty of Biological Sciences, University of Leeds, Leeds, LS2 9JT, United Kingdom
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Abstract
1. The aim of this study was to evaluate the effects of phytase and xylanase and their interaction on laying hen performance, egg quality, phosphorus (P) digestibility, phytate breakdown, volatile fatty acid (VFA) production and peptide YY concentration. 2. Two hundred and forty hens were allocated to cages at 22 weeks of age based on a 3 × 2 arrangement with phytase (0, 300 or 1500 FTU/kg) and xylanase (0 or 12 000 BXU/kg) as factors. 3. Phytase increased hen-day production (P < 0.05), daily egg mass (P < 0.05) and P digestibility with increasing levels of phytase (P < 0.001). Phytase fed at 1500 FTU/kg reduced IP6 and IP5 and increased myo-inositol concentration in gizzard digesta (P < 0.05). Phytase fed at 300 FTU/kg reduced IP6 in ileal digesta (P < 0.05); however, IP6 and IP5 were further reduced and myo-inositol increased when phytase was added at 1500 FTU/kg (P < 0.05). 4. Xylanase improved feed efficiency when phytase was fed at 300 FTU/kg (P < 0.05). In the absence of phytase, xylanase reduced dry matter and Ca digestibilities (P < 0.05). 5. Neither phytase nor xylanase had an effect on peptide YY or caecal VFA concentrations.
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Affiliation(s)
- A E Taylor
- a Faculty of Biological Sciences , University of Leeds , Leeds , UK
| | - M R Bedford
- b AB Vista Feed Ingredients Ltd , Marlborough , UK
| | - S C Pace
- a Faculty of Biological Sciences , University of Leeds , Leeds , UK
| | - H M Miller
- a Faculty of Biological Sciences , University of Leeds , Leeds , UK
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Sargeant HR, Miller HM, Shaw MA. Inflammatory response of porcine epithelial IPEC J2 cells to enterotoxigenic E. coli infection is modulated by zinc supplementation. Mol Immunol 2011; 48:2113-21. [PMID: 21803424 DOI: 10.1016/j.molimm.2011.07.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 06/28/2011] [Accepted: 07/06/2011] [Indexed: 11/25/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhoea in pigs and humans. The duration and severity of diarrhoea can be controlled using zinc supplementation, typically pharmacological levels of zinc oxide in pigs. In this study, IPEC J2 cells were used as an in vitro model of intestinal ETEC infection, with separate and simultaneous zinc treatment. Genomic analysis identified increased expression of a variety of innate immune response genes (NF-κB targets) in response to ETEC exposure, and several stress response genes in response to zinc exposure, provided as ZnO. Expression of genes involved in the innate immune response was reduced when cells were simultaneously exposed to ZnO, and it is suggested that ZnO treatment inhibits the induction of NF-κB in response to pathogens, possibly through up-regulated heat shock proteins. A similar response in vivo with consequent down-regulation in the inflammatory response would reduce further pathogen invasion, maintain normal gut function and maintain growth.
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Affiliation(s)
- Hannah R Sargeant
- Faculty of Biological Sciences, University of Leeds, Clarendon Road, Leeds LS2 9JT, United Kingdom
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Broom LJ, Miller HM, Kerr KG, Knapp JS. Effects of zinc oxide and Enterococcus faecium SF68 dietary supplementation on the performance, intestinal microbiota and immune status of weaned piglets. Res Vet Sci 2005; 80:45-54. [PMID: 15946717 DOI: 10.1016/j.rvsc.2005.04.004] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2004] [Accepted: 04/15/2005] [Indexed: 10/25/2022]
Abstract
The objective of this study was to determine the effects of zinc oxide (ZnO) and the probiotic Enterococcus faecium SF68 (Cylactin) dietary supplementation on the performance, intestinal microbiota and immune parameters of the weaned piglet reared under commercial conditions. The diets were devoid of antibiotic growth promoters (AGP). Two hundred and eight crossbred piglets were allocated to a 2 x 2 factorial experiment involving two levels of zinc oxide supplementation (0 or 3100 mg ZnO/kg feed), and two levels of E. faecium SF68 supplementation (0 or 1.4 x 10(9)CFU/kg feed (Cylactin ME10)). The diets were offered ad libitum for 20 days post-weaning. Piglet performance was assessed by calculating average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR) on a pen basis. In addition, components of the distal ileal digesta, tissue-associated and mesenteric lymph node (MLN) bacterial populations were enumerated and serum immunoglobulin G (IgG) and intestinal immunoglobulin A (IgA) concentrations were determined on days 6 and 20 post-weaning. Regression analysis was used to determine the relationship between the bacterial populations at the different sites. Supplementation of the post-weaning diet with either ZnO or E. faecium SF68 did not affect piglet performance. E. faecium SF68 did not affect gastrointestinal bacterial populations but did tend to reduce serum IgG (P<0.1) on day 20. Zinc oxide reduced anaerobic (P<0.05) and tended to decrease lactic acid (P<0.1) bacterial translocation to the MLN, and tended to increase intestinal IgA concentration (P<0.1) on day 20. Generally, luminal bacterial populations were found to be poor predictors of tissue-associated or MLN populations. ZnO and E. faecium SF68 dietary supplementation were ineffective under these trial conditions. Further investigations into the possible immunomodulator role of dietary ZnO are warranted.
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Affiliation(s)
- L J Broom
- School of Biology, The University of Leeds, Leeds LS2 9JT, UK.
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Barkley GR, Miller HM, Forbes JM. The ability of laying hens to regulate phosphorus intake when offered two feeds containing different levels of phosphorus. Br J Nutr 2004; 92:233-40. [PMID: 15333154 DOI: 10.1079/bjn20041182] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The ability of laying hens to adjust their intake of available P (AP) was investigated with a maize-soyabean diet fed to forty-eight individually caged birds in a 2 x 4 factorial experiment. From 19 to 25 weeks of age (phase 1) twenty-four birds were fed a normal-P (NP) diet (2.2 g AP/kg DM) and twenty-four were fed a low-P (LP) diet (1.1 g AP/kg). LP eggs were lighter (51 v. 54 (SEM 1.0) g; P<0.05), providing evidence that the LP diet was deficient in AP. From 25 to 28 weeks of age six hens from each phase 1 treatment were fed either the NP or LP diet alone or a choice of the LP and NP feeds or a choice of the LP feed and a phytase-supplemented (PP) feed (LP diet with 400 microbial phytase units/kg). With a choice of the NP and LP feeds, the hens fed the LP diet in phase 1 ate a smaller proportion of the LP feed (34 (SEM 12.0) %) than the hens fed the NP diet in phase 1 (72 (SEM 12.0) %; P<0.05), showing that P deficiency influenced subsequent selection for AP, i.e. an appetite for P was demonstrated. In those birds offered the LP and PP feeds, the presence of phytase in one of the two feeds significantly alleviated the effect of P deficiency on egg and body weights. The proportion of the LP diet chosen was not significantly affected by phase 1 treatment; it was not necessary for the hens to eat more than 50 % of PP feed.
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Affiliation(s)
- G R Barkley
- Centre for Animal Sciences, School of Biology, University of Leeds, LS2 9JT, UK
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Wilkinson J, Miller HM, McCracken K, Knox A, McNab J, Rose S. Effect of specific weight on the metabolizable energy content of four cultivars of wheat grain in ewes. Anim Feed Sci Technol 2003. [DOI: 10.1016/s0377-8401(03)00047-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Abstract
We studied the effects of feed intake and fatness on metabolic clearance rate (MCR) and half-life of progesterone in 40 ovariectomized gilts (10x4 littermates). One gilt from each litter was randomly allocated to each of four treatments in a randomized block design. Gilts were reared to be either lean (Ln), 113 kg BW and 10 mm backfat measured 65 mm from the midline at the level of the last rib (P2), or fat (F), 124 kg BW and 20 mm P2 backfat. They were ovariectomized and fitted with bilateral jugular catheters. Fat and Ln gilts were then fed either low (1.15 x maintenance energy, L), or high (2.30 x maintenance energy, H) feed intakes. Gilts received an i.m. injection of 130 mg of progesterone on two consecutive days (d1 and 2). From d 3, progesterone was infused at 5.4 mg/h (130 mg/d) for 60 h. Blood samples for progesterone analysis were taken during the last 24 h of infusion and for a further 72 h. Gilts were then slaughtered, and livers were sampled for microsomal studies. Fatness did not affect any aspect of progesterone metabolism measured. Postprandial MCR was greater in H than in L gilts, 103.0 vs. 76.1 mL x min(-1) x kg BW(-1) (P<.01), respectively. Feed intake did not affect the disappearance rate constant of progesterone (mean -.019), and the estimated half-life of progesterone was 36.5 h. High-intake gilts had larger proportional liver size (P<.001) than L gilts. Microsomal metabolism of progesterone and P450 enzyme concentration were similar across treatments. We conclude that increasing feed intake increases MCR of progesterone and could be used to manipulate progesterone concentration in sows.
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Affiliation(s)
- H M Miller
- Department of Animal Physiology and Nutrition, University of Leeds, UK.
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Miller HM, Tarver JD. The future population of Botswana. East Afr Econ Rev 1991; 7:85-91. [PMID: 12344802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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Affiliation(s)
- T Wolde-Michael
- School of Agriculture and Forestry, University of Melbourne, Parkville, Victoria
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Tarver JD, Miller HM. Rural-urban migration in a developing country: Botswana, Africa. Afr Q 1987; 24:22-33. [PMID: 12281861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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Holmes JH, Prasetyo S, Miller HM, Scheurmann EA. Effect of chronic heat load during pregnancy on birth weight, behaviour and body composition of Australian feral goat kids. Trop Anim Health Prod 1986; 18:185-90. [PMID: 3765120 DOI: 10.1007/bf02359533] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Six feral does maintained at elevated ambient temperatures (27.2 degrees - 34.8 degrees) for the last half of pregnancy had rectal temperatures (Tr) elevated by 0.4 degrees above 10 unstressed does. Heat-stressed twin-bearers were 0.15 degrees hotter than single-bearers and bore lighter kids (1.70 kg), than unstressed does (2.24 kg) while singles were less affected (2.22 kg versus 2.28 kg). Birth weight was more highly correlated (P less than 0.001) with the daily minimum Tr of the dam than with the mean or maximum Tr. Kids from heated does stood and began sucking as quickly as control kids but during the first six hours scored significantly (P less than 0.01) lower on a scale of general activity. There were no significant differences in body content of nitrogen, fat and ash or, when birth weight was considered, weight of hide, CNS and liver.
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Duttera MJ, Hummel GR, Brown EE, Miller HM. Entry into practice: problems encountered by rural and urban physicians. J Med Assoc Ga 1983; 72:775-8. [PMID: 6655377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Duttera MJ, Hummel GR, Brown EE, Miller HM. Entry into practice: problems in making the transition. J Fam Pract 1983; 17:529-532. [PMID: 6886654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Miller HM. Staffing a regional neonatal unit. Midwives Chron 1980; 93:352-353. [PMID: 6904799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
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Packer JE, Heighway CJ, Miller HM, Dobson BC. Free-radical reductions of arenediazonium ions in aqueous solution. IV. Kinetics of reactions of para-substituted diazonium ions with benzyl alcohol, isopropyl alcohol and methanol. Aust J Chem 1980. [DOI: 10.1071/ch9800965] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Electron-withdrawing
substituents are shown to increase the chain length of free-radical hydro-dediazoniation
reactions, but the actual reaction step causing the substituent effect depends
on the relative rates of propagation and termination reactions. With benzyl
alcohol as reducing agent the rate of the slow propagation step is increased,
while with isopropyl alcohol the rate of the termination step is decreased.
Rate constants for some reactions of radicals with diazonium ions are reported,
and the nature of some of these reactions and their implication for an
understanding of the homolysis of aromatic diazo compounds are discussed.
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Gardner EW, Miller HM, Lowney ED. Folded skin associated with underlying nevus lipomatosus. Arch Dermatol 1979; 115:978-9. [PMID: 464627] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
A mentally retarded female infant had abnormalities of the feet, hemiplegia, and an underlying nevus lipomatosus. To our knowledge, this represents the second reported case of marked folding of the skin; with an underlying nevus lipomatosus; this case demonstrated an association of this cutaneous disorder with multiple defects, including chromosomal abnormalities, which have not been previously reported.
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Miller HM, Woodhouse SP. Long chain fatty acid inhibition of sodium plus potassium-activated adenosine triphosphatase from rat heart. Aust J Exp Biol Med Sci 1977; 55:741-52. [PMID: 149532 DOI: 10.1038/icb.1977.69] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Long chain fatty acids were found to inhibit (Na+ + K+)-ATPase prepared from rat heart. Unsaturated and polyunsaturated fatty acids were more inhibitory than saturated fatty acids with myristic acid being the most inhibitory saturated fatty acid tested and linoleic the most inhibitory unsaturated fatty acid. As an example of fatty acid modification of the enzyme, inhibition of (Na+ + K+)-ATPase by oleate was examined. When compared to ouabain, inhibition of (Na+ + K+)-ATPase by oleate was found to be similar in that both were dependent on K+ concentration, but, in contrast to the almost instantaneous inhibition by ouabain, oleate inhibition was a slow process requiring over 20 min incubation at 37 degrees to produce maximum inhibition. Inhibition of rat heart (Na+ + K+)-ATPase by oleate was found to be readily reversible by washout. In the presence of albumin an oleate/albumin molar ratio greater than 7.5 was required for inhibition to occur. The activity of rat heart (Na+ + K+)-ATPase had a temperature optimum above 40 degrees and a discontinuous Arrhenius' plot with a transition temperature of 25 degrees. In the presence of oleate, however, the enzyme's optimum temperature decreased to below 40 degrees, the activation energy of the reaction at temperatures below 25 degrees was lowered from 24.7 kcal/mol to 12.6 kcal/mol and the enzyme had a linear Arrhenius' plot. The possibility of in vivo inhibition of cardiac (Na+ + K+)-ATPase under conditions of elevated fatty acids is discussed.
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Abstract
The surface topography of the intact 70S ribosomes and free 30S and 50S subunits from Bacillus stearothermophilus strain 2184 was investigated by lactoperoxidase-catalyzed iodination. Two-dimensional polyacrylamide gel electrophoresis was employed to separate ribosomal proteins for analysis of their reactivity. Free 50S subunits incorporated about 18% more 125I than did 50S subunits derived from 70S ribosomes, whereas, free 30S subunits and 30S subunits derived from 70S ribosomes incorporated similar amounts of 125I. Iodinated 70S ribosomes and subunits retained 62-78% of the protein synthesis activity of untreated particles and sedimentation profiles showed no gross conformational changes due to iodination. The proteins most reactive to enzymatic iodination were S4, S7, S10 and Sa of the small subunit and L2, L4, L5/9, L6 and L36 of the large subunit. Proteins S2, S3, S7, S13, Sa, L5/9, L10, L11 and L24/25 were labeled substantially more in the free subunits than in the 70S ribosome. Other proteins, including S5, S9, S12, S15/16, S18 and L36 were more extensively iodinated in the 70S ribosomes than in the free subunits. The locations of tyrosine residues in some homologous ribosomal proteins from B. stearothermophilus and E. coli are compared.
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Abstract
1. The rate of protein breakdown was determined on growing and non-growing cultures of thermophilic and mesophilic fungi. 2. In growing cells protein breakdown was negligible. 3. In non-growing cells the breakdown rate of total protein varied between 5.2%/h and 6.7%/h. These values were found to be dependent on both the temperature of the protein breakdown assay and the temperature of growth of the organism. 4. The rate of breakdown of soluble protein in thermophilic fungi was 9-15%/h whereas the rate in mesophilic fungi for the soluble protein fraction was only 4%/h.
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Abstract
Ribosomes and ribosomal subunits from the thermophile Penicillium duponti were found to be more thermostable than the corresponding particles from the mesophile Penicillium notatum. The thermostability of the ribosomes from both organisms was dependent on magnesium ion concentration. The dissociation of the 80-S ribosomes into 60-S and 40-S subunits occurred at higher magnesium ion concentrations for the mesophile than the thermophile.
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Abstract
During the first 50 days of a long-term period of incubation of lake sediments with inorganic mercury (Hg(2+)), low concentrations of methylinercury were observed to build up. Upon continued incubation there was a rapid decrease in amount of methylmercury in the system and a concomitant evolution of volatile inorganic mercury (Hg(0)). Transfer of the mixed culture to growth media containing methylmercury resulted in the degradation of methylmercury and the volatilization of Hg(0). Four bacterial isolates were obtained from the mixed culture which, in pure culture, rapidly degraded methylmercury to methane and Hg(0). The presence of methane in head space gases was confirmed by flameionization gas chromatography, and the presence of Hg(0) in head space gases was confirmed by mass spectrometry.
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Miller HM, Shepherd MG. Purification and properties of 6-phosphogluconate dehydrogenase from Penicillium duponti and Penicillium notatum. Can J Microbiol 1972; 18:1289-98. [PMID: 5052896 DOI: 10.1139/m72-199] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
6-Phosphogluconate dehydrogenase was isolated and partially purified from the thermophilic fungus Penicillium duponti and the mesophilic fungus Penicillium notatum. The specific activities of the purified enzymes were 17.5 and 22.0 respectively. Optimal activity was obtained at pH 8.0 for both enzymes. Non-linear Arrhenius plots were found for both enzymes with breaks at 30 °C for P. duponti 6-phosphogluconate dehydrogenase and 19 °C for P. notatum 6-phosphogluconate dehydrogenase. The thermal inactivation of 6-phosphogluconate dehydrogenase from both fungi exhibited first order kinetics, and the rate of inactivation for the thermophilic enzyme between 25 °C and 45 °C was only 25% that of the mesophilic enzyme. 6-Phosphogluconate dehydrogenase from both sources was protected from thermal inactivation by 6-phosphogluconic acid, high salt concentration, and high protein concentration. The thermophilic enzyme was found to be more resistant to the denaturants urea, acetamide, and sodium dodecylsulfate.
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Miller HM. THE SPECIALIZED DENTAL LIBRARY. Bull Med Libr Assoc 1941; 29:159-62. [PMID: 16016499 PMCID: PMC233424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Affiliation(s)
- H M Miller
- Library Committee, North Pacific College of Dentistry, Portland, Oregon
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