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1.
Mol Biol Rep ; 50(2): 1949-1952, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36385664

RESUMO

BACKGROUND: Lactoferrin (LTF) is an iron-binding glycoprotein found in milk and other exocrine secretion with antibacterial activity proposed as an alternative to mastitis treatment or prevention. LTF has been proposed as a candidate gene for mastitis resistance selection. The aim of this paper was to assess LTF promotor to explore variations with potential association to mastitis resistance in dairy cows from Honduras. METHODS: A resequencing of promotor and Exon I of LTF gene in extreme mastitis susceptibility cows (126 Holstein and Holstein crossbred) was performed. RESULTS: Eight polymorphisms were found in promotor region, four of them were novel variations. Two were important by frequency among extreme groups, but a polymorphism in - 421 A/T position was significantly (P = 0.0188) associated to mastitis susceptibility. CONCLUSION: Results support the key role of regulatory region of LTF gene. Some candidate genes are proposed in association with mastitis traits and implications are discussed.


Assuntos
Lactoferrina , Mastite Bovina , Feminino , Bovinos/genética , Animais , Humanos , Lactoferrina/genética , Genótipo , Polimorfismo Genético , Leite , Mastite Bovina/genética , Polimorfismo de Nucleotídeo Único/genética
2.
J Appl Genet ; 58(3): 363-371, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27987181

RESUMO

Cattle temperament is a complex trait, and molecular studies aimed at defining this trait are scarce. We used an interaction networks approach to identify new genes (interacting genes) and to estimate their effects and those of 19 dopamine- and serotonin-related genes on the temperament traits of Charolais cattle. The genes proopiomelanocortin (POMC), neuropeptide Y (NPY), solute carrier family 18, member 2 (SLC18A2) and FBJ murine osteosarcoma viral oncogene homologue (FOSFBJ) were identified as new candidates. Their potential to be associated with temperament was estimated according to their reported biological activities, which included interactions with neural activity, receptor function, targeting or synthesis of neurotransmitters and association with behaviour. Pen score (PS) and exit velocity (EV) measures were determined from 412 Charolais cows to calculate their temperament score (TS). Based on the TS, calm (n = 55; TS, 1.09 ± 0.33) and temperamental (n = 58; TS, 2.27 ± 0.639) cows were selected and genotyped using a 248 single-nucleotide variation (SNV) panel. Of the 248 variations in the panel, only 151 were confirmed to be polymorphic (single-nucleotide polymorphisms; SNPs) in the tested population. Single-marker association analyses between genotypes and temperament measures (EV, PS and/or TS) indicated significant associations of six SNPs from four candidate genes. The markers rs109576799 and rs43696138, located in the DRD3 and HTR2A genes, respectively, were significantly associated with both EV and TS traits. Four markers, rs110365063 and rs137756569 from the POMC gene and rs110365063 and rs135155082 located in SLC18A2 and DRD2, respectively, were associated with PS. The variant rs110365063 located in bovine SLC18A2 causes a change in the amino acid sequence from Ala to Thr. Further studies are needed to confirm the association of genetic profile with cattle temperament; however, our study represents important progress in understanding the regulation of cattle temperament by different genes with divergent functions.


Assuntos
Bovinos/genética , Dopamina/genética , Epistasia Genética , Serotonina/genética , Temperamento , Animais , Comportamento Animal , Feminino , Genótipo , Polimorfismo de Nucleotídeo Único
3.
J Anim Sci ; 94(11): 4570-4582, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27898967

RESUMO

The objective of this study was to perform a genomewide association study (GWAS) for growth traits in Charolais beef cattle and to identify SNP markers and genes associated with these traits. Our study included 855 animals genotyped using 76,883 SNP from the GeneSeek Genomic Profiler Bovine HD panel. The examined phenotypic data included birth, weaning, and yearling weights as well as pre- and postweaning ADG. After quality control, 68,337 SNP and 823 animals were retained in the analysis. The association analysis was performed using the principal components method via the egscore function of the GenABEL version 1.8-0 package in the R environment. Eighteen SNP located in 13 BTA were associated with growth traits ( < 5 × 10). The most important genes in these genomic regions were (), (), (), (), and ( [angiotensinase C]), due to their relationships with perinatal and postnatal survival, bone growth, cell adhesion, regulation of adipogenesis, and appetite. In conclusion, this study is the first to describe a GWAS conducted in beef cattle in Mexico and represents a basis for further and future research. This study detected new QTL associated with growth traits and identified 5 positional and functional candidate genes that are potentially involved in variations of the analyzed traits. Future analyses of these regions could help to identify useful markers for marker-assisted selection and will contribute to the knowledge of the genetic basis of growth in cattle and be a foundation for genomic predictions in Mexican Charolais cattle.


Assuntos
Bovinos/genética , Estudo de Associação Genômica Ampla/veterinária , Animais , Bovinos/crescimento & desenvolvimento , Feminino , Genoma , Genômica , Genótipo , Masculino , México , Fenótipo , Polimorfismo de Nucleotídeo Único , Gravidez
4.
Genet Mol Res ; 15(3)2016 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-27706683

RESUMO

Polymorphisms in candidate genes can produce significant and favorable changes in the phenotype, and therefore are useful for the identification of the best combination of favorable variants for marker-assisted selection. In the present study, an assessment to evaluate the effect of 11 single nucleotide polymorphisms (SNPs) in candidate genes on live weight traits of registered Brahman cattle was performed. Data from purebred bulls were used in this assessment. The dataset included birth (BW), weaning (WW), and yearling (YW) weights. A panel of 11 SNP markers, selected by their formerly reported or apparent direct and indirect association with live weight traits, was included in an assessment previously confirming their minimum allele frequency (<0.05). Live weights were adjusted BW (aBW), WW (aWW), and YW (aYW) using a generalized linear model, which included the fixed effects of herd and season of birth and the random effect of the sire and year of birth. An SNP in a growth hormone gene (GH4.1) was significantly related to aWW (P = 0.035) with an estimate substitution effect of 3.97 kg (P = 0.0210). In addition, a leptin SNP (LEPg.978) was significantly associated with aYW (P = 0.003) with an estimate substitution effect of 9.57 kg (P = 0.0007). The results suggest that markers GH4.1 and LEPg.978 can be considered as candidate loci for assisted genetic improvement programs in Mexican Brahman cattle.


Assuntos
Peso Corporal , Hormônio do Crescimento/genética , Leptina/genética , Polimorfismo de Nucleotídeo Único , Característica Quantitativa Herdável , Alelos , Animais , Cruzamento , Bovinos , Feminino , Expressão Gênica , Frequência do Gene , Loci Gênicos , Marcadores Genéticos , Modelos Lineares , Masculino , México , Modelos Genéticos
5.
Trop Anim Health Prod ; 48(8): 1729-1738, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27696327

RESUMO

Genetic trends are commonly used to verify genetic improvement; however, there are few reports on beef cattle in Mexico. Data from 1998 to 2013 from four Charolais bull breeding farms were examined to verify the genetic responses to different breeding management and selection criteria. Analysis included the comparison of regression lines of breeding values for birth (BW), weaning (WW) and yearling weights (YW), and maternal weaning weight (MWW) on the year of birth of the animals. Results revealed differential genetic progress for BW and YW and indicated that the overall analysis may have diluted the perception of genetic progress from the farmer's point of view. The use of breeding values as a tool for selection is effective to achieve genetic progress, even in negatively correlated traits, such as birth weight and yearling weight.


Assuntos
Criação de Animais Domésticos , Peso ao Nascer , Peso Corporal , Bovinos/fisiologia , Animais , Cruzamento , Bovinos/genética , Fazendas , Feminino , Masculino , México , Seleção Genética , Clima Tropical
6.
Poult Sci ; 95(10): 2449-54, 2016 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-27418659

RESUMO

The objective was to characterize texture properties of raw and cooked broiler fillets (Pectoralis major) with the wooden breast condition (WBC) using the instrumental texture techniques of Meullenet-Owens Razor Shear (MORS) and Texture Profile Analysis (TPA). Deboned (3 h postmortem) broiler fillets were collected from a commercial plant and categorized as normal, moderate, or severe WBC based on the incidence and severity of diffuse hardened areas throughout fillets and the degree of palpable hardness. The fillets were then either stored at 4°C overnight or in a -20°C freezer. The MORS and TPA of the raw samples were determined at 24 h postmortem for fresh samples and after thawing overnight for frozen samples. The same measurements were also taken after the samples were cooked to 78°C. Regardless of freshness (fresh vs. frozen-thawed), cooking (raw vs. cooked), and degree of WBC, both MORS force and energy of the WBC samples were higher than that of the normal samples (P < 0.05). For TPA adhesiveness and resilience, there were no differences between normal and WBC samples (P > 0.05). However, average TPA hardness and chewiness measurements of the fillets with WBC were higher than the normal fillets (P < 0.05). Regardless of texture measurement, there were no interactions between freshness and the wooden condition or no differences between moderate and severe WBC fillets (P > 0.05). These results demonstrate that there are significant differences in instrumental texture properties between normal fillets and those exhibiting the WBC. The WBC fillets required more force to cut through, harder, and chewier than normal breast muscles. These results suggest that cooked WBC meat would likely be tougher than cooked normal meat.


Assuntos
Culinária , Armazenamento de Alimentos , Carne/análise , Músculos Peitorais/fisiologia , Animais , Galinhas , Congelamento
7.
Genet Mol Res ; 15(1)2016 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-26909995

RESUMO

The aim of this study was to analyze the allelic frequency distribution and segregation among breeds and/or between different cattle genetic groups of four novel single nucleotide polymorphisms of the bovine DRD1 and DRD5 genes and one reported SNP from the DRD4 gene. One hundred and nine-animals from ten different cattle breeds were genotyped and allelic frequencies for each locus were estimated. There were significant differences in the allelic frequencies (P < 0.05) among breeds for the DRD1 and DRD5 markers. The allelic frequencies for markers DRD1-825A>G and DRD5-378C>T were also significantly different between groups differing in genetic background. Because differences in temperament have been reported between Bos taurus taurus and B. taurus indicus breeds and their crosses, further studies are needed to investigate if any association exists between described markers and cattle behavior traits.


Assuntos
Polimorfismo de Nucleotídeo Único , Característica Quantitativa Herdável , Receptores Dopaminérgicos/genética , Temperamento , Alelos , Animais , Comportamento Animal , Cruzamento , Bovinos , Feminino , Frequência do Gene , Genótipo , Masculino , Fenótipo , Análise de Componente Principal , Isoformas de Proteínas/genética
8.
Genet Mol Res ; 9(2): 875-83, 2010 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-20467980

RESUMO

The IGF1 gene (insulin-like growth factor 1) is a candidate gene for marker-assisted selection strategies. A single nucleotide polymorphism in the promoter region (IGF1/SnaBI) has been reported to be associated with production traits in several cattle breeds. Here, we report its allelic frequencies in Charolais and Beefmaster breeds; we confirm its association with three growth traits: weaning weight, weaning weight adjusted to 210 days and preweaning weight gain in the Charolais breed. In addition, we designed a strategy to search these breeds for new polymorphisms in four coding regions of the gene. A C/A transversion was detected in intron 4, but it was not associated with the growth traits. A single nucleotide polymorphism (IGF1/SnaBI) is proposed as a selection marker for Mexican Charolais cattle; validation of its association with weaning weight, weaning weight adjusted to 210 days and preweaning weight gain, could complement the genetic evaluations of this breed through marker-assisted management strategies.


Assuntos
Fator de Crescimento Insulin-Like I/genética , Polimorfismo Genético , Alelos , Criação de Animais Domésticos/métodos , Animais , Peso Corporal , Cruzamento , Bovinos , Feminino , Frequência do Gene , México , Especificidade da Espécie , Aumento de Peso/genética
9.
Arch. latinoam. nutr ; 58(3): 303-308, sept. 2008. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-588727

RESUMO

Los alimentos de origen vegetal en especial las frutas y los vegetales presentes en la dieta de acuerdo a estudios epidemiológicos realizados, pueden ejercer un efecto protector contra algunas enfermedades tales como el cáncer y trastornos cardiovasculares. Esta propiedad se debe a la presencia de compuestos bioactivos con capacidad antioxidante como la vitamina C, E, b-caroteno, y una mezcla compleja de compuestos fenólicos. El objetivo de este trabajo fue estudiar en una serie de productos de origen vegetal, la relación entre el contenido de polifenoles totales y la actividad antioxidante. Los polifenoles fueron determinados luego de su extracción en solución metanólica por el método de Folin-Ciocalteau. La actividad antioxidante fue evaluada usando los métodos del b-caroteno/linoleato, el poder reductor, y la actividad antirradical. Los productos estudiados fueron las semillas y/o pericarpios de: Theobroma cacao (cacao), Campsiandra comosa Benth (chiga), Sorghum bicolor, L. Moench (sorgo), Melicoccus bijugatus (mamón). El pericarpio del mamón presentó el más bajo contenido de polifenoles (1,40 EAGg/100g) y el cacao el más alto (6,66 EAGg/100g). El poder reductor del cacao resultó ser el más alto y equivalente al poder reductor de 5,80g de ácido ascórbico /100g, seguido por la chiga. Asimismo, las semillas de chiga y de cacao presentaron una actividad antioxidante, comparable a la del butil hidroxianisol antioxidante sintético. El mayor poder antirradical lo presentó la semilla de chiga con un EC50 de 2,67 g/gDPPH. El contenido de polifenoles totales se correlaciona bien con la actividad antioxidante; asimismo, estas semillas o granos podrían tener los efectos beneficiosos para la salud atribuidos a otras frutas y vegetales.


Foods from plant origin not only provide human diet with certain antioxidant vitamins (C, E and β-carotene), but also a complex mixture of polyphenols, with antioxidant activity. Numerous studies have been focused on the protective and preventing effect of this antioxidant activity on certain degenerative illnesses such as cardiovascular, cancer, and neurological diseases, cataracts and oxidative stress dysfunctions. The objective of this work was to evaluate total polyphenol content and antioxidant activity of several seeds, nuts, or grains such as Theobroma cacao, Campsiandra comosaBenth (chiga), Sorghum bicolor, L. Moench, Melicoccus bijugatus (genip). Total polyphenol content was assessed by the Folin-Ciocalteau method and the antioxidant activity by the β.carotene/linoleate, reducing power, and the anti-radical activity methods. Results showed genip pericarp with the lowest polyphenol content (1.40 gGAE/100g), and cacao beans with the highest (6.66 gGAE/100g). Reducing power of cacao beans was also the highest and similar to the reducing power of 5,80g ascorbic acid /100g, followed by Campsiandra comosa. Moreover, Campsiandra comosa and cacao seeds presented an antioxidant activity comparable to that of the butylhydroxianisol, a synthetic antioxidant. The highest anti-radical activity was shown by Campsiandra comosa with an EC50 of 2.67 g/gDPPH. Total polyphenol content shows a good correlation with the antioxidant activity. Moreover, these seeds might have the same health beneficial effects attributed to other fruits and vegetables.


Assuntos
Antioxidantes/análise , Cacau , Compostos Fenólicos , Planticorpos , Sorghum , Análise de Alimentos
10.
Appl Microbiol Biotechnol ; 80(1): 167-77, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18523764

RESUMO

Native strains of Trichoderma isolated from sorghum and common bean crop soils were investigated to assess their biocontrol potential over the phytopathogenic fungus Macrophomina phaseolina, isolated from diseased plants. The Trichoderma strains were characterized with a polyphasic approach, which combined the analysis of their morphological characteristics, enzymatic activity, macro- and microculture test results, rDNA restriction patterns (AFLP), ITS1-5.8S-ITS2 rDNA sequences, and protein profiles. The integration of these data sets can be used to select new isolates as biological control agents against native fungal phytopathogens. In general, we observed a positive correlation between the secretion of beta-1,3-glucanase and N-acetylhexosaminidase, and the biocontrol capacities of all the Trichoderma isolates. Strains with the best hyperparasitic behavior against M. phaseolina isolated from diseased bean and sorghum were Trichoderma sp. (TCBG-2) and Trichoderma koningiopsis (TCBG-8), respectively.


Assuntos
Antibiose , Ascomicetos/fisiologia , Fabaceae/microbiologia , Doenças das Plantas/microbiologia , Microbiologia do Solo , Sorghum/microbiologia , Trichoderma/isolamento & purificação , Trichoderma/fisiologia , Análise do Polimorfismo de Comprimento de Fragmentos Amplificados , DNA Fúngico/genética , DNA Ribossômico/genética , DNA Espaçador Ribossômico/genética , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , Trichoderma/classificação , Trichoderma/genética
11.
Arch Latinoam Nutr ; 58(3): 303-8, 2008 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-19137995

RESUMO

Foods from plant origin not only provide human diet with certain antioxidant vitamins (C, E and beta-carotene), but also a complex mixture of polyphenols, with antioxidant activity. Numerous studies have been focused on the protective and preventing effect of this antioxidant activity on certain degenerative illnesses such as cardiovascular, cancer, and neurological diseases, cataracts and oxidative stress dysfunctions. The objective of this work was to evaluate total polyphenol content and antioxidant activity of several seeds, nuts, or grains such as Theobroma cacao, Canpsiandra comosa Benth (chiga), Sorghum bicolor, L. Moench, Melicoccus bijugatus (genip). Total polyphenol content was assessed by the Folin-Ciocalteau method and the antioxidant activity by the beta carotene/linoleate, reducing power, and the anti-radical activity methods. Results showed genip pericarp with the lowest polyphenol content (1.40 gGAE/100 g), and cacao beans with the highest (6.66 gGAE/100 g). Reducing power of cacao beans was also the highest and similar to the reducing power of 5.80 g ascorbic acid/100 g, followed by Campsiandra comosa. Moreover, Campsiandra comosa and cacao seeds presented an antioxidant activity comparable to that of the butylhydroxianisol, a synthetic antioxidant. The highest anti-radical activity was shown by Campsiandra comosa with an EC50 of 2.67 g/gDPPH. Total polyphenol content shows a good correlation with the antioxidant activity. Moreover, these seeds might have the same health beneficial effects attributed to other fruits and vegetables.


Assuntos
Antioxidantes/análise , Flavonoides/análise , Frutas/química , Nozes/química , Fenóis/análise , Sementes/química , Cacau/química , Carica/química , Humanos , Polifenóis , Sorghum/química , beta Caroteno/química
12.
Int J Cosmet Sci ; 27(2): 107-14, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18492160

RESUMO

The objective of the present work was to evaluate the possible use of Myrosma cannifolia starch L.F. Maranthaceae ('Guapo'), as a raw material in heterogeneous systems or powdered cosmetic and pharmaceutical products formulation. The starch chemical and physical characteristics, physico-chemical properties, and rheological behaviour, previously studied, were considered. Flowing characteristics, particle size distribution, water absorption capacity at 25 degrees C (ambient temperature), and toxicity were assessed. Results showed that Myrosma starch complies with the USP and British pharmacopoeia, and presented a normal particle distribution. More than 25% of the granules had a diameter >23.81 mum and the average size of particles was >16.92 mum. When compared with talc, 'guapo' starch presented higher values for water absorption capacity and flowing characteristics. Starch showed negative local toxicity, and low acute toxicity in vitro on two human dermis cell types. The amylographic study and the difractograms suggest the possible use of this starch in heterogeneous systems. A facial transparent powder was formulated and some of its properties were determined by sensorial analysis. It was concluded that the M. cannifolia starch presents certain characteristics useful in the formulation of new powdered products.

13.
Appl Microbiol Biotechnol ; 64(5): 675-85, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-14740190

RESUMO

Trichoderma harzianum is a widely distributed soil fungus that antagonizes numerous fungal phytopathogens. The antagonism of T. harzianum usually correlates with the production of antifungal activities including the secretion of fungal cell walls that degrade enzymes such as chitinases. Chitinases Chit42 and Chit33 from T. harzianum CECT 2413, which lack a chitin-binding domain, are considered to play an important role in the biocontrol activity of this strain against plant pathogens. By adding a cellulose-binding domain (CBD) from cellobiohydrolase II of Trichoderma reesei to these enzymes, hybrid chitinases Chit33-CBD and Chit42-CBD with stronger chitin-binding capacity than the native chitinases have been engineered. Transformants that overexpressed the native chitinases displayed higher levels of chitinase specific activity and were more effective at inhibiting the growth of Rhizoctonia solani, Botrytis cinerea and Phytophthora citrophthora than the wild type. Transformants that overexpressed the chimeric chitinases possessed the highest specific chitinase and antifungal activities. The results confirm the importance of these endochitinases in the antagonistic activity of T. harzianum strains, and demonstrate the effectiveness of adding a CBD to increase hydrolytic activity towards insoluble substrates such as chitin-rich fungal cell walls.


Assuntos
Antifúngicos/metabolismo , Celulose/metabolismo , Quitinases/metabolismo , Trichoderma/enzimologia , Botrytis/crescimento & desenvolvimento , Quitinases/genética , Cinética , Micélio/crescimento & desenvolvimento , Controle Biológico de Vetores/métodos , Phytophthora/crescimento & desenvolvimento , Estrutura Terciária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Rhizoctonia/crescimento & desenvolvimento , Transformação Genética/genética , Transformação Genética/fisiologia , Trichoderma/genética
14.
Appl Environ Microbiol ; 67(9): 4279-85, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11526034

RESUMO

We isolated spontaneous mutants from Saccharomyces cerevisiae (baker's yeast V1) that were resistant to 2-deoxy-D-glucose and had improved fermentative capacity on sweet doughs. Three mutants could grow at the same rate as the wild type in minimal SD medium (0.17% Difco yeast nitrogen base without amino acids and ammonium sulfate, 0.5% ammonium sulfate, 2% glucose) and had stable elevated levels of maltase and/or invertase under repression conditions but lower levels in maltose-supplemented media. Two of the mutants also had high levels of phosphatase active on 2-deoxy-D-glucose-6-phosphate. Dough fermentation (CO2 liberation) by two of the mutants was faster and/or produced higher final volumes than that by the wild type, both under laboratory and industrial conditions, when the doughs were supplemented with glucose or sucrose. However, the three mutants were slower when fermenting plain doughs. Fermented sweet bakery products obtained with these mutants were of better quality than those produced by the wild type, with regard to their texture and their organoleptic properties.


Assuntos
Desoxiglucose/farmacologia , Mutação , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/crescimento & desenvolvimento , Pão , Meios de Cultura , Farmacorresistência Fúngica , Fermentação , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo
15.
J Am Chem Soc ; 123(15): 3493-8, 2001 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-11472121

RESUMO

Dimerization of calix[4]arene ureidopeptides is demonstrated for the first time. Two calix[4]arenes tetrasubstituted in the upper rim with -NHCONH(L)LeuNHC(8)H(17) (1) and -NHCONH(L)Leu(D)Leu-OMe (2) were prepared and studied by NMR, circular dicroism, and gel permeation chromatography. Compound 2 self-assembles through urea-urea hydrogen bonds, as well as by an additional set of hydrogen bonds provided by the peptide side chains, with participation of the ester carbonyls. The absence of such group in 1 causes the monomer structure to be favored in this case.

16.
J Agric Food Chem ; 49(4): 1861-6, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11308337

RESUMO

Spontaneous yeast mutants isolated in continuous culture as resistant to toxic amino acid analogues, able to increase up to 40 times their free amino acid pool of Thr, up to 160 times their pool of Met, or up to 20 times their pool of Lys, were characterized with regard to properties of industrial interest. Growth rate, mu (h(-1)), and biomass yield, Y (g/L), of the amino acid overproducing mutants (AA(S)) were in many cases similar to those of the wild type, whereas their free amino acid content was substantially increased in laboratory and industrial media (molasses). Doughs fermented with 3% baker's yeast and 0.5% AA(S) mutants produced bakery products that displayed texture similar to those fermented with 3.5% baker's yeast, but the former had a considerable improvement of their taste and aroma. On the other hand, bread content of the essential amino acids Lys, Met, and Thr provided by yeast was also increased.


Assuntos
Aminoácidos/metabolismo , Pão/normas , Saccharomyces cerevisiae/metabolismo , Biomassa , Pão/microbiologia , Fermentação , Aditivos Alimentares , Mutação , Valor Nutritivo , Saccharomyces cerevisiae/crescimento & desenvolvimento , Olfato , Paladar
17.
Rev Iberoam Micol ; 17(1): S31-6, 2000 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-15762779

RESUMO

The use of the fungal genus Trichoderma to control fungal plant diseases is a promising alternative to the use of chemical compounds. The aim of this work has been to obtain Trichoderma strains with improved capacity as biological control agents. To do so, the hydrolytic capacity on fungal cell walls of strains of the fungus Trichoderma harzianum has been increased. On one hand, transformation experiments with genes which coded for chitinases and glucanases have been carried out in T. harzianumstra ins. On the other hand, the medium composition has also been modified in order to eliminate proteolytic degradation of some of the overproduced enzymes. Finally, hybrid chitinolytic enzymes with substrate-binding domains have been produced as an alternative to obtain improved biocontrol strains. The transformant strains, when compared with the wild type, showed improved antifungal capacity against the phytopathogenic fungus Rhizoctonia solani, in in vitro experiments.

18.
Arch Latinoam Nutr ; 50(3): 286-90, 2000 Sep.
Artigo em Espanhol | MEDLINE | ID: mdl-11347300

RESUMO

A comparison between the chemical composition and physical characteristics of ñame congo (Dioscorea bulbifera) and mapuey (Dioscorea trifida) white and purple varieties, was made. The tubers were evaluated for their physical attributes (morphology, size and weight). The chemical analysis was done according to AOAC methods (1990) and the pasting properties of the flours were evaluated using the Brabender Viscoamilograph. The mapuey tubers have an elongated shape, with one end wider while ñame congo presents a rounded shape. The results of the chemical analysis show that mapuey tubers have more proteins content (p < or = 0.05) than either purple mapuey tubers purple or ñame congo tubers. The flours overall viscosity, measured at the same concentration, was higher for white mapuey varieties. The gelatinization temperature range was similar among the flours. The negative breakdown datas suggest that the flours viscosity increases during the gelatinization process of all flours. Neither suspensions showed a viscosity peak. Set-back and consistency were lower in the ñame congo flour. The absence of a viscosity peak and the high temperature stability of the ñame congo flour make it an ideal ingredient for instant soup mixes. The flours high viscosity level developed by white and purple mapuey varieties should make it a suitable sauces thickener.


Assuntos
Farinha/análise , Verduras/anatomia & histologia , Verduras/química , Reologia , Viscosidade
20.
Arch Latinoam Nutr ; 47(1): 81-4, 1997 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-9429649

RESUMO

High cholesterol saturated lipids ingestion has been linked to the increment of coronary diseases, particularly atherosclerosis. In this study, samples of viscera and chicken meat, as well as manufactured chicken products are characterized from the point of view of their sterol content, specially cholesterol, with the purpose to determine their nutritional quality and to contribute with the development of Venezuelan food composition tables. Gas-liquid chromatography was the method chosen for the separation and quantification of cholesterol and fitosterols eventually present. The method involves lipids extraction, direct saponification, extraction of the unsaponifiable matter and its injection in the gas chromatograph. The average cholesterol values in mg/100 g. wet sample were: 31.13 (manufactured chicken breast); 57,35 (ham like type of product made with chicken); 69.02 (chicken sausages); 60.46 (chicken "bologna").


Assuntos
Galinhas , Colesterol/isolamento & purificação , Produtos da Carne/análise , Carne/análise , Animais , Venezuela
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