Saccharomyces Cerevisiae cell wall dietary supplementation on the performance and intestinal mucosa development and integrity of broiler chickens vaccinated against coccidiosis

This study was carried out to verify if Saccharomyces cerevisiae cell wall (SCCW) dietary supplementation (0.2%) was capable of protecting the intestinal mucosa of broiler chickens vaccinated against coccidiosis. Body weight gain, feed intake, feed conversion and intestinal mucosa morphometric parameters and epithelial loss were evaluated. In the experiment,400 day-old male chicks were distributed according to a completely randomized design in a 2x2 factorial arrangement. The following treatments were applied: T1 - no vaccination/ no SCCW supplementation; T2 - no vaccination/SCCW supplementation; T3 - vaccination/no SCCW supplementation; and T4 - vaccination/SCCW supplementation to four replicates of 25 birds each. Birds were vaccinated on the first day of age using a spray vaccine (Coccivac B®, Coopers), containing E. acervulina, E. maxima, E. mivati and E. tenella. S. cerevisiae cell wall was supplied from the first day of age. Live performance, intestinal morphometric parameters and epithelial loss were evaluated at 14, 21 and 28 days of age. Performance was affected by vaccination only at 21-days of age, when body weight gain was reduced in the vaccinated birds, but no body weight difference was observed on day 28. Vaccine also increased the crypt depth (p<0.05) in the duodenum and jejunum, suggesting a high cell activity in the crypt:villus transition area to maintain the epithelial cell turnover. Villi number/area (103,269 µm²) was not affected (p>0.05) by vaccine or cell wall supplementation, and epithelial loss was more pronounced in the duodenum and jejunum. In conclusion, the findings of this study suggest that S. cerevisiae cell wall supplementation may be an useful management tool to maintain the intestinal integrity of broilers vaccinated against coccidiosis.

Development and application of a Saccharomyces cerevisiae-expressed nucleocapsid protein-based enzyme-linked immunosorbent assay for detection of antibodies against infectious bronchitis virus

A Saccharomyces cerevisiae-expressed nucleocapsid (N) polypeptide of the M41 strain of infectious bronchitis virus (IBV) was used as antigen in a recombinant yeast-expressed N protein-based enzyme-linked immunosorbent assay (Y-N-ELISA). The Y-N-ELISA was rapid, sensitive, and specific for detecting chicken serum antibodies to IBV, and it compared favorably with a commercial ELISA.

Inflammation induced by inactivated Aeromonas hydrophila in Nile tilapia fed diets supplemented with Saccharomyces cerevisiae

The inflammatory response and hernatological parameters among Nile tilapia (Oreochromis niloticus) supplemented with Saccharomyces cerevisiae were evaluated six and 24 h after inoculation with inactivated Aeromonas hydrophila into the swim bladder. Six groups were formed (n = 10 each): G1 was treated with non-supplemented feed+injection with 0.65% saline solution; G2 with non-supplemented feed+ inoculation with A. hydrophila: G3 with feed containing 2% yeast+ injection with saline; G4 with feed containing 2% yeast + inoculation with A. hydrophila: G5 with feed containing 0.3% cell wall + injection with saline: and G6 with feed containing 0.3% cell wall + inoculation with A. hydrophila. In the groups inoculated with bacteria, the responses were more intense (P<0.05) than in those injected with saline. The groups receiving supplement that were inoculated with A. hydrophila accumulated a greater total number of cells at the lesion site (P<0.05) than did the non-supplemented groups, after six and 24 h. The groups receiving cell wall presented greater total accumulation of cells (P<0.005) that did those receiving yeast. The differential count showed that there were significantly greater number of thrombocytes (P< 0.05) and lower number of neutrophils, macrophages and lymphocytes (P<0.05) in the groups that received supplement, after 6 and 24 h, in relation to the non-supplemented groups. The values in the erythrocyte count, hemoglobin concentration and blood measurement indices did not differ statistically. The variation in circulating thrombocyte and leukocyte counts suggests that the inflammatory stimulus caused recruitment from reserve compartments to the blood. The groups that received yeast or yeast cell wall supplements presented increased nonspecific acute inflammatory response, thus suggesting that this has a beneficial effect on the immunological defense system. Published by Elsevier B.V.

Conditions affecting production of functional muscle recombinant alpha-tropomyosin in Saccharomyces cerevisiae

Yeasts are attractive hosts for heterologous protein production as they follow the general eukaryotic post-translational modification pattern. The well-known Saccharomyces cerevisiae has been used to produce a large variety of foreign proteins. The proper function of muscle tropomyosin depends on a specific modification at its N-terminus. Although tropomyosin has been produced in different expression systems, only the recombinant protein produced in the yeast Pichia pastoris has native-like functional properties. In this paper we describe the production of functional skeletal muscle tropomyosin in the yeast S. cerevisiae. The recombinant protein was produced in high amounts and production was strongly affected by genetic and environmental factors, including plasmid copy number, promoter strength, and growth media composition. (C) 2003 Elsevier B.V. (USA). All rights reserved.

Utilização da levedura desidratada (Saccharomyces cerevisiae) para leitões na fase inicial

Foi conduzido um experimento com o objetivo de avaliar o efeito da adição de diferentes níveis de levedura (Saccharomyces cerevisiae) desidratada na ração sobre o desempenho e a morfologia intestinal de leitões na fase inicial. Foram utilizados 280 leitões (fêmeas e machos castrados) de uma linha genética comercial de suínos, desmamados com 21 dias de idade e distribuídos em 20 baias, de acordo com o delineamento em blocos ao acaso, com 5 repetições e 4 tratamentos experimentais (0, 5, 10 e 15% de adição de levedura). Aos 45 dias de idade, três leitões de cada tratamento foram abatidos e colhidas amostras do duodeno e do jejuno para estudo da morfologia intestinal. Os níveis crescentes de levedura desidratada nas rações não afetaram (P>0,05) o ganho de peso, o consumo de ração e a conversão alimentar dos leitões. Com relação à morfologia do duodeno e do jejuno, também não houve efeito (P>0,05) dos níveis de levedura estudados sobre a altura das vilosidades, das profundidades das criptas e da relação vilosidade/cripta. Os resultados permitiram concluir que a levedura desidratada pode ser adicionada em até 15% nas rações de suínos na fase inicial.

Effect of acibenzolar-S-methyl and Saccharomyces cerevisiae on the activation of Eucalyptus defences against rust

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Susceptibility of Saccharomyces cerevisiae and lactic acid bacteria from the alcohol industry to several antimicrobial compounds

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Quantificação da floculação de Saccharomyces cerevisiae por bactérias contaminantes da fermentação alcoólica

O assentamento de células de leveduras no fundo das dornas e perdas de células nas centrífugas podem ser causadas por bactérias floculantes, contaminantes naturais da fermentação alcoólica industrial. Estes problemas levam a queda no rendimento e produtividade do etanol. O presente trabalho visa a caracterização da floculação de Saccharomyces cerevisiae por Lactobacillus fermentum CCT 1396. As células de leveduras e bactérias foram misturadas e a floculação das células quantificadas por espectrofotometria. Concentrações de bactérias numa faixa de 0,4 a 3,8g/L (biomassa seca) foram testadas a fim de determinar a ótima concentração de bactérias necessária para provocar a floculação das leveduras. O efeito de pH na floculação das células de leveduras e bactérias foi determinado. 1,38g/L de bactéria foi necessário para a floculação, de 65,4g/L de células de levedura com tempo de contato entre as células (sob agitação) de 15 minutos e repouso de 20 minutos. No pH 3,0 pouco efeito na floculação celular foi detectado e as células continuaram floculadas, mas na faixa de pH 2,0 -- 2,5 a floculação foi próxima de zero. Esta técnica pode ser utilizada para o controle da floculação de leveduras de indústrias de produção de álcool, para determinar a origem desta floculação, já que trata-se de uma técnica fácil, econômica e rápida.

Direct observation of oxidative stress on the cell wall of Saccharomyces cerevisiae strains with atomic force microscopy

We imaged pores on the surface of the cell wall of three different industrial strains of Saccharomyces cerevisiae using atomic force microscopy. The pores could be enlarged using 10 mM diamide, an SH residue oxidant that attacks surface proteins. We found that two strains showed signs of oxidative damage via changes in density and diameter of the surface pores. We found that the German strain was resistant to diamide induced oxidative damage, even when the concentration of the oxidant was increased to 50 mM. The normal pore size found on the cell walls of American strains had diameters of about 200nm. Under conditions of oxidative stress the diameters changed to 400nm.This method may prove to be a useful rapid screening process (45-60 min) to determine which strains are oxidative resistant, as well as being able to screen for groups of yeast that are sensitive to oxidative stress. This rapid screening tool may have direct applications in molecular biology (transference of the genes to inside of living cells) and biotechnology (biotransformations reactions to produce chiral synthons in organic chemistry.

A theoretical study on cytosine tautomers in aqueous media by using continuum models

B3LYP/6-31 + + G** and MP2/6-31 + + G** calculations have been carried out to study six tautomers of the nucleic acid base cytosine in aqueous media. Solvent effects have been analyzed using the self-consistent reaction field theory with two continuum methods. Relative stabilities and optimized geometries have been calculated for the tautomers and compared with experimental data. The present results show the importance of electrostatic solvent effects in determining observable properties of the cytosine tautomers. The amino-oxo form (C1) is the most abundant tautomer in aqueous media while the other amino-oxo form (C4) is the most energetically favored when solvent effects are included. These results can be justified by the larger values of the dipole moments for both C1 and C4 tautomers. Theoretical and experimental results of the harmonic vibrational frequencies and rotational constants show good agreement. (C) 2000 Elsevier B.V. B.V. All rights reserved.

Avaliação da produção de leite e contagem de células somáticas em bovinos leiteiros suplementads com Saccharomyces cerevisiae como fonte de zinco orgânico

The aim of the evaluation of milk production and somatic cell count of dairy cow supplemented with Saccharomyces cerevisiae as a source of organic zinc for 180 days, 25 Holstein cows were selected, randomly chosen from a flock of 189 lactating cows. The animals were distributed in two groups, namely group 1 (G1) which holded 10 cows supplemented and group 2 (G2) with 15 animals without supplementation. The production of milk was measured by the control official milkman of the Assocition Paranaense of Creators of Bovine of the Holstein in seven moments during the 180 days. The samples of milk were collected of each animal, being submitted to the electronic counting of somatic cells. The results demonstrate that the supplemented of organic zinc didn't alter the production of milk, however it was capable to maintain low the counting of somatic cells. The data of the present work suggest that to use supplemented of organic zinc in the diet of cows milk, increase the quality of the produced milk and consequently the remuneration for the producer.

The Saccharomyces cerevisiae COQ10 gene encodes a START domain protein required for function of coenzyme Q in respiration

Deletion of the Saccharomyces cerevisiae gene YOL008W, here referred to as COQ10, elicits a respiratory defect as a result of the inability of the mutant to oxidize NADH and succinate. Both activities are restored by exogenous coenzyme Q(2). Respiration is also partially rescued by COQ2, COQ7, or COQ8/ABC1, when these genes are present in high copy. Unlike other coq mutants, all of which lack Q(6), the coq10 mutant has near normal amounts of Q(6) in mitochondria. Coq10p is widely distributed in bacteria and eukaryotes and is homologous to proteins of the aromatic-rich protein family Pfam03654 and to members of the START domain superfamily that have a hydrophobic tunnel implicated in binding lipophilic molecules such as cholesterol and polyketides. Analysis of coenzyme Q in polyhistidine-tagged Coq10p purified from mitochondria indicates the presence 0.032-0.034 mol of Q(6)/mol of protein. We propose that Coq10p is a Q(6)-binding protein and that in the coq10 mutant Q(6) it is not able to act as an electron carrier, possibly because of improper localization.

Dihydrolipoyl dehydrogenase as a source of reactive oxygen species inhibited by caloric restriction and involved in Saccharomyces cerevisiae aging

Replicative life span in Saccharomyces cerevisiae is increased by glucose (G1c) limitation [ calorie restriction (CR)] and by augmented NAD(+). Increased survival promoted by CR was attributed previously to the NAD(+)-dependent histone deacetylase activity of sirtuin family protein Sir2p but not to changes in redox state. Here we show that strains defective in NAD(+) synthesis and salvage pathways (pnc1 Delta, npt1 Delta, and bna6 Delta) exhibit decreased oxygen consumption and increased mitochondrial H2O2 release, reversed over time by CR. These null mutant strains also present decreased chronological longevity in a manner rescued by CR. Furthermore, we observed that changes in mitochondrial H2O2 release alter cellular redox state, as attested by measurements of total, oxidized, and reduced glutathione. Surprisingly, our results indicate that matrix-soluble dihydrolipoyl-dehydrogenases are an important source of CR-preventable mitochondrial reactive oxygen species (ROS). Indeed, deletion of the LPD1 gene prevented oxidative stress in npt1 Delta and bna6 Delta mutants. Furthermore, pyruvate and alpha-ketoglutarate, substrates for dihydrolipoyl dehydrogenase-containing enzymes, promoted pronounced reactive oxygen release in permeabilized wild-type mitochondria. Altogether, these results substantiate the concept that mitochondrial ROS can be limited by caloric restriction and play an important role in S. cerevisiae senescence. Furthermore, these findings uncover dihydrolipoyl dehydrogenase as an important and novel source of ROS leading to life span limitation.

Higher respiratory activity decreases mitochondrial reactive oxygen release and increases life span in Saccharomyces cerevisiae

Increased replicative longevity in Saccharomyces cerevisiae because of calorie restriction has been linked to enhanced mitochondrial respiratory activity. Here we have further investigated how mitochondrial respiration affects yeast life span. We found that calorie restriction by growth in low glucose increased respiration but decreased mitochondrial reactive oxygen species production relative to oxygen consumption. Calorie restriction also enhanced chronological life span. The beneficial effects of calorie restriction on mitochondrial respiration, reactive oxygen species release, and replicative and chronological life span could be mimicked by uncoupling agents such as dinitrophenol. Conversely, chronological life span decreased in cells treated with antimycin (which strongly increases mitochondrial reactive oxygen species generation) or in yeast mutants null for mitochondrial superoxide dismutase (which removes superoxide radicals) and for RTG2 (which participates in retrograde feedback signaling between mitochondria and the nucleus). These results suggest that yeast aging is linked to changes in mitochondrial metabolism and oxidative stress and that mild mitochondrial uncoupling can increase both chronological and replicative life span.