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1.
J Dairy Sci ; 104(1): 357-366, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33131815

RESUMO

This study examined the effect of 3-nitrooxypropanol (3-NOP), an investigational substance, on enteric methane emission, milk production, and composition in Holstein dairy cows. Following a 3-wk covariate period, 48 multi- and primiparous cows averaging (± standard deviation) 118 ± 28 d in milk, 43.4 ± 8 kg/d milk yield, and 594 ± 57 kg of body weight were blocked based on days in milk, milk yield, and enteric methane emission and randomly assigned to 1 of 2 treatment groups: (1) control, no 3-NOP, and (2) 3-NOP applied at 60 mg/kg feed dry matter. Inclusion of 3-NOP was through the total mixed ration and fed for 15 consecutive weeks. Cows were housed in a freestall barn equipped with a Calan Broadbent Feeding System (American Calan Inc., Northwood, NH) for monitoring individual dry matter intake and fed ad libitum once daily. Enteric gaseous emissions (methane, carbon dioxide, and hydrogen) were measured using 3 GreenFeed (C-Lock Inc., Rapid City, SD) units. Dry matter intake, cow body weight, and body weight change were not affected by 3-NOP. Compared with the control group, 3-NOP applied at 60 mg/kg feed dry matter decreased daily methane emission, emission yield, and emission intensity by 26, 27, and 29%, respectively. Enteric emission of carbon dioxide was not affected, and hydrogen emission was increased 6-fold by 3-NOP. Administration of 3-NOP had no effect on milk and energy-corrected milk yields and feed efficiency, increased milk fat and milk urea nitrogen concentrations, and increased milk fat yield but had no other effects on milk components. Concentration of C6:0 and C8:0 and the sum of saturated fatty acids in milk fat were increased by 3-NOP. Total trans fatty acids and the sum of polyunsaturated fatty acids were decreased by 3-NOP. In this experiment, 3-NOP decreased enteric methane daily emission, yield, and intensity without affecting dry matter intake and milk yield, but increased milk fat in high-producing dairy cows.


Assuntos
Bovinos/metabolismo , Trato Gastrointestinal/efeitos dos fármacos , Lactação/efeitos dos fármacos , Metano/metabolismo , Leite/química , Propanóis/administração & dosagem , Animais , Dieta/veterinária , Ácidos Graxos/análise , Feminino , Trato Gastrointestinal/metabolismo , Lipídeos/análise , Leite/efeitos dos fármacos , Nitrogênio/análise
2.
J Oral Rehabil ; 45(1): 34-40, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28965355

RESUMO

As the understanding of temporomandibular disorders' (TMDs) aetiologies and treatments develops from non-evidence-based to evidence-based approaches, the availability of sound information will likewise grow and need to be disseminated. The purpose of this study is to describe the content most commonly viewed in YouTube videos related to TMDs or "TMJ" and see whether videos from different sources have different content. Video information was gathered by searching YouTube for the term "TMJ," and data were recorded related to descriptive information as well as content. Statistical analyses included Kruskal-Wallis H Test, Spearman's Rho and univariate logistic regression. The sources of upload were Consumer (n = 62), Professional (n = 29) and News (n = 9). There were almost no statistically significant differences in content distribution among video sources. Videos garnered a total of 4 749 360 views, with an overall median of 7014.5 views. About two-thirds of the videos (68/100) explained what "TMJ" is, with a surprising third of Professional videos (9/29) not covering the subject. Roughly half of the videos mentioned at least one reason "TMJ" occurs (55/100), and seven in ten mentioned some kind of treatment (70/100). Video names mentioned a cure or treatment in 64 cases, while the other 36 referred to TMJ anatomy or "TMJ" aetiology. Future research should focus on ways to popularise professional videos with reliable information for those who are searching on YouTube for advice related to "TMJ."


Assuntos
Internet , Transtornos da Articulação Temporomandibular , Articulação Temporomandibular , Medicina Baseada em Evidências , Humanos , Disseminação de Informação , Comportamento de Busca de Informação , Mídias Sociais , Gravação em Vídeo
3.
J Dairy Sci ; 94(5): 2431-9, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21524535

RESUMO

Fifteen ruminally cannulated, nonlactating Holstein cows were used to measure the effects of 2 strains of Saccharomyces cerevisiae, fed as active dried yeasts, on ruminal pH and fermentation and enteric methane (CH(4)) emissions. Nonlactating cows were blocked by total duration (h) that their ruminal pH was below 5.8 during a 6-d pre-experimental period. Within each block, cows were randomly assigned to control (no yeast), yeast strain 1 (Levucell SC), or yeast strain 2 (a novel strain selected for enhanced in vitro fiber degradation), with both strains (Lallemand Animal Nutrition, Montréal, QC, Canada) providing 1 × 10(10) cfu/head per day. Cows were fed once daily a total mixed ration consisting of a 50:50 forage to concentrate ratio (dry matter basis). The yeast strains were dosed via the rumen cannula daily at the time of feeding. During the 35-d experiment, ruminal pH was measured continuously for 7 d (d 22 to 28) by using an indwelling system, and CH(4) gas was measured for 4 d (d 32 to 35) using the sulfur hexafluoride tracer gas technique (with halters and yokes). Rumen contents were sampled on 2 d (d 22 and 26) at 0, 3, and 6h after feeding. Dry matter intake, body weight, and apparent total-tract digestibility of nutrients were not affected by yeast feeding. Strain 2 decreased the average daily minimum (5.35 vs. 5.65 or 5.66), mean (5.98 vs. 6.24 or 6.34), and maximum ruminal pH (6.71 vs. 6.86 or 6.86), and prolonged the time that ruminal pH was below 5.8 (7.5 vs. 3.3 or 1.0 h/d) compared with the control or strain 1, respectively. The molar percentage of acetate was lower and that of propionate was greater in the ruminal fluid of cows receiving strain 2 compared with cows receiving no yeast or strain 1. Enteric CH(4) production adjusted for intake of dry matter or gross energy, however, did not differ between either yeast strain compared with the control but it tended to be reduced by 10% when strain 2 was compared with strain 1. The study shows that different strains of S. cerevisiae fed as active dried yeasts vary in their ability to modify the rumen fermentative pattern in nonlactating dairy cows. Because strain 2 tended (when compared with strain 1) to lower CH(4) emissions but increase the risk of acidosis, it may be prudent to further evaluate this strain in cattle fed high-forage diets, for which the risk of acidosis is low but CH(4) emissions are high.


Assuntos
Acidose/veterinária , Doenças dos Bovinos/prevenção & controle , Metano/biossíntese , Rúmen/metabolismo , Fermento Seco/administração & dosagem , Acidose/prevenção & controle , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos , Dieta/veterinária , Digestão/fisiologia , Feminino , Fermentação/fisiologia , Concentração de Íons de Hidrogênio , Rúmen/química , Saccharomyces cerevisiae , Fermento Seco/classificação
4.
J Anim Sci ; 93(3): 1218-28, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26020898

RESUMO

Two experiments were conducted to evaluate the effect of wheat dried distillers grains with solubles (DDGS) and fibrolytic enzymes (FE) on ruminal fermentation, in situ ruminal and in vivo total tract digestibility, growth performance, and feeding behavior of growing beef cattle. In Exp. 1, 6 ruminally cannulated Angus heifers (average BW of 794 ± 44.2 kg) were used in a 6 × 6 Latin square design with 2 × 3 factorial arrangement of treatments. Treatments were a control diet consisting of 50% barley silage, 10% grass hay, and 40% barley grain-based concentrate (CON) and the CON with 15% DDGS substituted for barley grain (WDG) combined with either 0, 1, or 2 mL FE/kg diet DM, respectively. Inclusion of DDGS increased total tract digestibility of CP ( < 0.01), NDF ( = 0.04), and ADF ( = 0.03). Increasing FE linearly ( = 0.03) increased CP digestibility without affecting the digestibility of other nutrients. There were no effects of DDGS inclusion or FE on ruminal pH or VFA concentration except that propionate was greater ( = 0.04) with the WDG. In situ ruminal DM and NDF disappearance of barley silage was greater ( < 0.04) in heifers fed the WDG than in heifers fed the CON after 24 h of incubation. Increasing FE linearly ( = 0.03) increased in situ NDF disappearance of barley silage after 24 h of incubation. In Exp. 2, 120 weaned steers (initial BW of 289 ± 11.0 kg) were fed diets similar to those in Exp. 1. The steers fed the WDG had greater ( < 0.01) final BW, ADG, DMI, and G:F compared with steers fed the CON. Increasing FE did not alter ADG or G:F but tended ( < 0.07) to linearly decrease DMI. There were interactions ( < 0.02) between DDGS and FE on eating rate and the time spent at the feed bunk. Supplementing FE decreased ( < 0.01) time at the bunk and increased ( < 0.01) eating rate for steers fed the WDG but not for steers fed the CON. Eating rate ( < 0.01) and meal frequency ( = 0.02) were greater but eating duration was shorter ( < 0.01) for steers fed the WDG than for those fed the CON. These results indicate that inclusion of wheat DDGS in a growing diet increased total tract digestibility of NDF and CP and improved the feed efficiency of steers. Moreover, supplementation of FE in barley silage-based growing diets may also have the potential to increase profits, with the evidence of the trend for a decline on DMI without decreasing ADG when adding FE.


Assuntos
Bovinos/crescimento & desenvolvimento , Digestão/efeitos dos fármacos , Enzimas/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Rúmen/efeitos dos fármacos , Triticum , Ração Animal/análise , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Bovinos/fisiologia , Celulase/administração & dosagem , Celulase/farmacologia , Dieta/veterinária , Suplementos Nutricionais , Digestão/fisiologia , Grão Comestível , Endo-1,4-beta-Xilanases/administração & dosagem , Endo-1,4-beta-Xilanases/farmacologia , Enzimas/administração & dosagem , Comportamento Alimentar/fisiologia , Feminino , Fermentação/efeitos dos fármacos , Fermentação/fisiologia , Masculino , Rúmen/metabolismo , Silagem
5.
Animal ; 9(10): 1740-6, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26051447

RESUMO

The objectives of this study were to determine: (1) the effect of wheat dried distillers grain with solubles (DDGS) inclusion, and (2) dietary feed enzyme (FE; Econase XT) supplementation in a finishing diet containing wheat DDGS on fatty acid profile of the pars costalis diaphragmatis muscle of beef cattle. A total of 160 crossbred yearling steers with initial BW of 495 ± 38 kg were blocked by BW and randomized into 16 pens (10 head/pen). The pens were randomly assigned to one of the four treatments: (1) control (CON; 10% barley silage and 90% barley grain-based concentrate, dry matter (DM) basis); (2) diet containing 30% wheat DDGS in place of barley grain without FE (WDG); (3) WDG diet supplemented with low FE (WDGL; 1 ml FE/kg DM); and (4) WDG diet supplemented with high FE (2 ml FE/kg DM). The pars costalis diaphragmatis muscle samples were collected from cattle at slaughter at the end of the finishing period (120 days) with a targeted live weight of 650 kg. No differences in organic matter intake, final BW and average daily gain were observed among treatments. However, steers fed WDG had greater (P<0.01) feed conversion ratio than those fed CON, and increasing FE application in wheat DDGS-based diets tended (P<0.10) to linearly decrease feed conversion ratio. In assessing the effects of including WDG diets without FE, concentration of total polyunsaturated fatty acids (PUFA) in muscle tended to be greater (P<0.10) for steers fed WDG than steers fed CON. In addition, inclusion of wheat DDGS into the diet increased (P<0.05) concentration of CLA and vaccenic acid (VA) in muscle and also resulted in a higher (P<0.05) ratio of n-6/n-3 PUFA compared with that from steers fed CON diet. Increasing FE application in wheat DDGS-based diets did not modify the concentrations of individual or total fatty acids. These results suggest that inclusion of wheat DDGS in finishing diets may improve fatty acid profile of beef muscle which could benefit human health.


Assuntos
Bovinos/fisiologia , Dieta/veterinária , Suplementos Nutricionais , Ácidos Graxos/análise , Carne Vermelha/normas , Silagem/análise , Ração Animal , Animais , Grão Comestível , Ácidos Graxos Ômega-3/análise , Hordeum , Masculino , Músculos/anatomia & histologia , Triticum
6.
N Z Med J ; 100(831): 554-7, 1987 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-3451139

RESUMO

This study describes the long term outcome for patients admitted for treatment of alcoholism at Mahu clinic, Sunnyside Hospital, Christchurch. Details of 1000 consecutive admissions were recorded from March 1972 to October 1976. This included 616 patients with the data base taken from the first admission as some were readmitted. After known deaths were excluded in October 1983, 100 patients were randomly selected for followup until October 1984. Followup time varied from 8-12.5 years. Forty percent were found to be recovered. Implications for improved salvage rates are discussed.


Assuntos
Alcoolismo/terapia , Hospitalização , Adulto , Alcoolismo/mortalidade , Feminino , Seguimentos , Unidades Hospitalares , Humanos , Institucionalização , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Prognóstico , Qualidade de Vida , Recidiva
7.
N Z Med J ; 92(670): 323-5, 1980 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-6934433

RESUMO

The following report contains a summary of the analysis of 1000 consecutive inpatient admissions to Mahu Clinic, an alcohol treatment unit. The results obtained show an average of four and half months abstinence after discharge from the clinic with a 48.8 percent long term recovery rate. This reflects the acceptance of recovery following relapse in alcoholism.


Assuntos
Alcoolismo/reabilitação , Fatores Etários , Consumo de Bebidas Alcoólicas , Alcoolismo/mortalidade , Feminino , Seguimentos , Humanos , Masculino , Fatores Sexuais , Inquéritos e Questionários
8.
N Z Med J ; 103(882): 1-3, 1990 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-2304671

RESUMO

Six hundred and sixteen alcoholics were admitted to an inpatient alcoholism clinic (Mahu clinic, Sunnyside Hospital, Christchurch) between 1972 and 1976. The national register of deaths was searched for deaths of these patients up until 30 September 1983. Eighty-three deaths were recorded which, when compared with the general population, matched for age and sex, yielded a standardised mortality ratio of 1.6, that is 60% higher than expected. However because the patients were nearly all under 65 years of age the absolute death rate was not high--98% survived one year and 86% survived ten years. Similarly the excess death rate was quite low at 6 extra deaths per 1000 alcoholic years.


Assuntos
Alcoolismo/mortalidade , Hospitalização , Análise Atuarial , Adolescente , Adulto , Idoso , Causas de Morte , Feminino , Seguimentos , Unidades Hospitalares , Humanos , Masculino , Pessoa de Meia-Idade , Nova Zelândia , Distribuição de Poisson , Análise de Regressão , Fatores de Risco , Fatores Sexuais , Fatores de Tempo
9.
Appl Ergon ; 2(3): 162-70, 1971 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15676697

RESUMO

This article describes an investigation of engineering-drawing comprehension. A variety of subjects was used so that results would have a wider application.

10.
J Anim Sci ; 92(2): 724-32, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24398831

RESUMO

The study addressed the importance of yeast (Saccharomyces cerevisiae) viability for reducing the incidence of subacute ruminal acidosis (SARA) and improving total tract nutrient digestibility in beef heifers. Six ruminally cannulated beef heifers (680 ± 50 kg BW) were used in a replicated 3 × 3 Latin square design and were fed a diet consisting of 40% barley silage, 10% chopped grass hay, and 50% barley grain-based concentrate (DM basis). Treatments were 1) no yeast (Control), 2) active dried yeast (ADY; 4 g providing 10(10) cfu/g; AB Vista, Marlborough, UK), and 3) killed dried yeast (KDY; 4 g autoclaved ADY). The treatments were directly dosed via the ruminal cannula daily at the time of feeding. The periods consisted of 2 wk of adaptation (d 1 to 14) and 7 d of measurements (d 15 to 21). Ruminal pH was continuously measured (d 15 to 21) using an indwelling system. Ruminal contents were sampled on d 15 and 17 at 0, 3, 6, 9, and 12 h after feeding. Total tract nutrient digestibility was measured using an external marker (YbCl3) from d 15 to 19. No treatment difference was observed for DMI (P = 0.86). Yeast supplementation (ADY and KDY) tended to increase total tract digestibility of starch (P = 0.07) whereas no effects were observed on digestibility of other nutrients. Both ADY and KDY elevated minimum (P < 0.01) and mean ruminal pH (P = 0.02) whereas no effects were observed on maximum pH (P = 0.12). Irrespective of its viability, yeast supplementation was effective in reducing time that ruminal pH was below 5.8 (P < 0.01) and 5.6 (P < 0.01). No treatment differences were observed for the ruminal VFA profile and lactate concentration. No treatment differences were observed on the relative population size of Streptococcus bovis, Fibrobacter succinogenes, and Megasphaera elsdenii (P > 0.10); however, the proportion of Ruminococcus flavefaciens in solid fraction of digesta was greater with KDY (P = 0.05). The study demonstrates the positive effects of yeast, irrespective of its viability, in reducing the severity of SARA. However, further studies are required to evaluate the importance of yeast viability for other dietary conditions, particularly when the risk of acidosis is high.


Assuntos
Ração Animal/análise , Bovinos/fisiologia , Dieta/veterinária , Digestão/fisiologia , Rúmen/fisiologia , Leveduras/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Animais , DNA Bacteriano/genética , Feminino , Fermentação , Reação em Cadeia da Polimerase , Rúmen/microbiologia
11.
J Anim Sci ; 92(9): 3978-87, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24987082

RESUMO

Two experiments were conducted to evaluate the effects of adding an exogenous fibrolytic enzyme (FE) on ruminal pH and fermentation, digestibility, and growth performance of feedlot beef cattle fed a finishing diet containing wheat dried distillers grains with solubles (DDGS). In Exp. 1, 4 ruminally cannulated Angus heifers (average BW of 807 ± 93.9 kg) were used in a replicated 4 × 4 Latin square design. Treatments were 1) control (CON; 10% barley silage and 90% barley grain-based concentrate), 2) CON diet substituting 30% wheat DDGS for barley grain (WDG), 3) WDG diet supplemented with low FE (WDGL), and 4) WDG diet supplemented with high FE (WDGH). Heifers fed WDG had less (P = 0.01) total tract DM digestibility than heifers fed CON. Increasing FE linearly (P < 0.05) increased starch digestibility without affecting digestibility of other nutrients. Addition of FE also reduced (P = 0.03) ruminal ammonia-N (NH3-N) concentration but did not affect VFA concentration. Moreover, application of FE to wheat DDGS linearly increased in situ ruminal DM (P < 0.01) and NDF (P = 0.02) disappearance after 48 h of incubation. In Exp. 2, 160 yearling steers (initial BW = 495 ± 37.9 kg) were fed the same diets as in Exp. 1. No differences in DMI, final BW, ADG, dietary NEg, or carcass characteristics were observed among diets. However, the steers fed WDG had less (P < 0.05) G:F and greater number of (P < 0.01) abscessed livers than steers fed CON. Increasing FE application in wheat DDGS diets did not affect DMI, final BW, or ADG but tended (P < 0.09) to linearly improve feed efficiency and decreased (P = 0.03) the incidence of abscessed livers. These results demonstrated adverse effects of including wheat DDGS in finishing diets on feed digestion, feed efficiency, and animal health. Application of FE in wheat DDGS-based diets potentially improved starch digestion, protein metabolism in the rumen, feed efficiency, and animal health.


Assuntos
Bovinos/crescimento & desenvolvimento , Celulase/farmacologia , Digestão/fisiologia , Fermentação/fisiologia , Hordeum/química , Rúmen/fisiologia , Xilosidases/farmacologia , Amônia/metabolismo , Animais , Dieta/veterinária , Suplementos Nutricionais , Digestão/efeitos dos fármacos , Fermentação/efeitos dos fármacos , Abscesso Hepático , Masculino , Triticum/química
12.
Vet Rec ; 134(19): 508, 1994 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-8073600
15.
Environ Sci Technol ; 43(15): 5599-604, 2009 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-19731650

RESUMO

High nitrogen (N) loading to coastal aquatic systems can be expressed as increased algal production and subsequent low dissolved oxygen. In April, 2008, predictions for extreme flood stage for the Lower Mississippi River triggered the opening of the Bonnet Carré Spillway, a major release valve for the river. The spillway diverted approximately 8 km3 of water over one month of operation into Lake Pontchartrain with a concomitant 10000 t of NO3-N. Satellite imagery, physical, water quality, and chlorophyll a (chl a) measurements show that the Mississippi River plume mixed with < 40% of the lake during this time, and much of the nutrient load was transported to the coastal ocean. Nitrate, dissolved reactive phosphorus (P), and dissolved silica (Si) concentrations were 4.8, 5.0, and 3.2 times higher, respectively, within the river plume when compared with those of the lake water. Despite the high nutrient concentrations within the river plume, phytoplankton biomass, evidenced by chl a concentrations, was low. Much of the nutrient load appeared to bypass the lake and was transported to the coastal ocean during the opening of the diversion. The potential removal of a total of 7.6% of the N load from the Mississippi River during the one month of flood level flow may have been a contributing factor in the lower than predicted hypoxia zone off the Louisiana coast during the summer of 2008.


Assuntos
Planejamento em Desastres/métodos , Inundações , Água Doce , Biomassa , Clorofila/análise , Clorofila A , Ecossistema , Hipóxia , Louisiana , Nitratos/química , Fósforo/análise , Fósforo/química , Fitoplâncton/metabolismo , Rios , Dióxido de Silício/química , Poluentes Químicos da Água/análise
16.
J Appl Bacteriol ; 74(4): 353-9, 1993 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8486540

RESUMO

Bacteria that use sorbitol, xylitol, maltitol and dulcitol (galactitol) were isolated from the sheep rumen following enrichments in which bacteria were grown in rumen fluid medium where the sugar alcohol was the only added energy source. Only isolates obtained with sorbitol and maltitol grew sufficiently rapidly to be considered for enrichment by the sugar alcohol in vivo. Isolate SS2, a strain of Selenomonas ruminantium var. lactilytica which grew on sorbitol at 0.87 h-1, was selected for further study and a rifampicin-resistant mutant, SS2/R5, was isolated to facilitate tracking in the mixed population. Despite an initial transient increase in numbers, a significant population of S. ruminantium SS2/R5 failed to establish in sheep which were dosed twice daily with 10 g of sorbitol. Continuous infusion of sorbitol increased numbers only slightly compared with twice-daily dosing. In vitro experiments indicated that strain SS2/R5 grew less well in the presence of other rumen organisms, particularly ciliate protozoa, than in pure culture. Furthermore, the concentration of sorbitol in vivo was lower than predicted from in vitro experiments, indicating that sorbitol was absorbed rapidly from the rumen. Similar observations were made with xylitol, dulcitol and maltitol. Proposed enrichment strategies that use sugar alcohols or other materials to support the growth of introduced bacteria will thus have to take account of the combined problems of microbe-microbe interactions and the loss of the compounds by absorption from the rumen.


Assuntos
Bactérias Anaeróbias Gram-Negativas/isolamento & purificação , Bactérias Anaeróbias Gram-Negativas/metabolismo , Rúmen/microbiologia , Álcoois Açúcares/metabolismo , Animais , Galactitol/metabolismo , Bactérias Anaeróbias Gram-Negativas/crescimento & desenvolvimento , Maltose/análogos & derivados , Maltose/metabolismo , Ovinos , Sorbitol/metabolismo , Xilitol/metabolismo
17.
Appl Environ Microbiol ; 59(9): 3147-9, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8215385

RESUMO

Treatment of Trypticase peptides with acetic anhydride, succinic anhydride, or maleic anhydride inhibited their breakdown to ammonia by rumen microorganisms by an average of 89% after 12 h of incubation in vitro. All three treatments gave similar protection. Acetylation also protected dipeptides containing lysine and methionine from degradation. However, more effective protection was obtained by linking lysine and methionine as N-epsilon-methionyl lysine.


Assuntos
Peptídeos/metabolismo , Rúmen/microbiologia , Anidridos Acéticos , Sequência de Aminoácidos , Animais , Caseínas , Dipeptídeos/química , Dipeptídeos/metabolismo , Anidridos Maleicos , Peptídeos/química , Hidrolisados de Proteína , Ovinos , Anidridos Succínicos
18.
Biochem Biophys Res Commun ; 263(1): 58-62, 1999 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-10486253

RESUMO

The potential for two complementary fragments of DNA from a clone from the ruminal bacterium Prevotella albensis to encode sequences with homology to at least part of functional proteins is described. One strand contains a sequence with high homology to dnaK, a member of the hsp70 family, and the other strand contains a sequence with some homology to glutamate dehydrogenase genes. Overlapping of these two genes on opposite strands has been reported in eukaryotic species, and is now reported for the first time in a bacterial species. Further investigation of previously described dnaK genes demonstrates that it is more widespread than might be anticipated, with all thirty other dnaK genes investigated also retaining long sequences encoding at least part of a sequence with high homology to a glutamate dehydrogenase gene.


Assuntos
Proteínas de Bactérias/genética , DNA Bacteriano/genética , Proteínas de Escherichia coli , Prevotella/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Primers do DNA/genética , DNA Antissenso/genética , Glutamato Desidrogenase/genética , Proteínas de Choque Térmico HSP70/genética , Dados de Sequência Molecular , Rúmen/microbiologia , Homologia de Sequência de Aminoácidos , Especificidade da Espécie
19.
J Appl Bacteriol ; 75(2): 129-34, 1993 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8407673

RESUMO

The Gram-negative rumen bacteria Fibrobacter succinogenes S85, Prevotella ruminicola M384 and Veillonella parvula L59 were grown in media containing successively increasing concentrations of the ionophores, monensin and tetronasin. All three species became more resistant to the ionophore with which they were grown. Increased resistance to one ionophore caused increased resistance to the other, and cross-resistance to another ionophore--lasalocid--and an antibiotic--avoparcin. Recovery of tetronasin-resistant bacteria from the rumen of monensin-fed sheep increased and vice versa, indicating that similar cross-resistance occurred in vivo.


Assuntos
Antibacterianos/farmacologia , Bacteroides/efeitos dos fármacos , Bactérias Anaeróbias Gram-Negativas/efeitos dos fármacos , Ionóforos/farmacologia , Monensin/farmacologia , Rúmen/microbiologia , Veillonella/efeitos dos fármacos , Animais , Bacteroides/crescimento & desenvolvimento , Contagem de Colônia Microbiana , Resistência Microbiana a Medicamentos , Fermentação/efeitos dos fármacos , Furanos/farmacologia , Bactérias Anaeróbias Gram-Negativas/crescimento & desenvolvimento , Ovinos , Veillonella/crescimento & desenvolvimento
20.
Appl Environ Microbiol ; 64(8): 2836-43, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9687438

RESUMO

The influence of peptides and amino acids on ammonia assimilation and de novo synthesis of amino acids by three predominant noncellulolytic species of ruminal bacteria, Prevotella bryantii B14, Selenomonas ruminantium HD4, and Streptococcus bovis ES1, was determined by growing these bacteria in media containing 15NH4Cl and various additions of pancreatic hydrolysates of casein (peptides) or amino acids. The proportion of cell N and amino acids formed de novo decreased as the concentration of peptides increased. At high concentrations of peptides (10 and 30 g/liter), the incorporation of ammonia accounted for less than 0.16 of bacterial amino acid N and less than 0.30 of total N. At 1 g/liter, which is more similar to peptide concentrations found in the rumen, 0.68, 0.87, and 0.46 of bacterial amino acid N and 0.83, 0.89, and 0.64 of total N were derived from ammonia by P. bryantii, S. ruminantium, and S. bovis, respectively. Concentration-dependent responses were also obtained with amino acids. No individual amino acid was exhausted in any incubation medium. For cultures of P. bryantii, peptides were incorporated and stimulated growth more effectively than amino acids, while cultures of the other species showed no preference for peptides or amino acids. Apparent growth yields increased by between 8 and 57%, depending on the species, when 1 g of peptides or amino acids per liter was added to the medium. Proline synthesis was greatly decreased when peptides or amino acids were added to the medium, while glutamate and aspartate were enriched to a greater extent than other amino acids under all conditions. Thus, the proportion of bacterial protein formed de novo in noncellulolytic ruminal bacteria varies according to species and the form and identity of the amino acid and in a concentration-dependent manner.


Assuntos
Aminoácidos/biossíntese , Bactérias Anaeróbias Gram-Negativas/metabolismo , Prevotella/metabolismo , Rúmen/microbiologia , Streptococcus bovis/metabolismo , Amônia/metabolismo , Animais , Caseínas/metabolismo , Meios de Cultura , Bactérias Anaeróbias Gram-Negativas/crescimento & desenvolvimento , Nitrogênio/metabolismo , Peptídeos/metabolismo , Prevotella/crescimento & desenvolvimento , Hidrolisados de Proteína/metabolismo , Ovinos , Streptococcus bovis/crescimento & desenvolvimento
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