ABSTRACT
Abstract The acquired pellicle formation is the first step in dental biofilm formation. It distinguishes dental biofilms from other biofilm types. Objective To explore the influence of salivary pellicle formation before biofilm formation on enamel demineralization. Methodology Saliva collection was approved by Indiana University IRB. Three donors provided wax-stimulated saliva as the microcosm bacterial inoculum source. Acquired pellicle was formed on bovine enamel samples. Two groups (0.5% and 1% sucrose-supplemented growth media) with three subgroups (surface conditioning using filtered/pasteurized saliva; filtered saliva; and deionized water (DIW)) were included (n=9/subgroup). Biofilm was then allowed to grow for 48 h using Brain Heart Infusion media supplemented with 5 g/l yeast extract, 1 mM CaCl2.2H2O, 5% vitamin K and hemin (v/v), and sucrose. Enamel samples were analyzed for Vickers surface microhardness change (VHNchange), and transverse microradiography measuring lesion depth (L) and mineral loss (∆Z). Data were analyzed using two-way ANOVA. Results The two-way interaction of sucrose concentration × surface conditioning was not significant for VHNchange (p=0.872), ∆Z (p=0.662) or L (p=0.436). Surface conditioning affected VHNchange (p=0.0079), while sucrose concentration impacted ∆Z (p<0.0001) and L (p<0.0001). Surface conditioning with filtered/pasteurized saliva resulted in the lowest VHNchange values for both sucrose concentrations. The differences between filtered/pasteurized subgroups and the two other surface conditionings were significant (filtered saliva p=0.006; DIW p=0.0075). Growing the biofilm in 1% sucrose resulted in lesions with higher ∆Z and L values when compared with 0.5% sucrose. The differences in ∆Z and L between sucrose concentration subgroups was significant, regardless of surface conditioning (both p<0.0001). Conclusion Within the study limitations, surface conditioning using human saliva does not influence biofilm-mediated enamel caries lesion formation as measured by transverse microradiography, while differences were observed using surface microhardness, indicating a complex interaction between pellicle proteins and biofilm-mediated demineralization of the enamel surface.
Subject(s)
Animals , Cattle , Saliva/chemistry , Sucrose/chemistry , Tooth Demineralization/microbiology , Biofilms/growth & development , Dental Enamel/microbiology , Reference Values , Saliva/microbiology , Sucrose/analysis , Surface Properties , Microradiography/methods , Dental Enamel/chemistry , Dental Pellicle/microbiology , Pasteurization , HardnessABSTRACT
ABSTRACT Arctium lappa is known to have antioxidant and antidiabetic effects in traditional medicine. Objectives: The aim of this paper was to study the effects of A. lappa root extract (AE) on lipid profile and hepatic enzyme levels in sucrose-induced metabolic syndrome (MS) in female rats. The study used 40 adult female Wistar rats weighing 150 g-250 g randomly divided into five groups: control, metabolic syndrome (MS), metabolic syndrome+AE at 50,100, 200 mg/kg. MS was induced by administering 50% sucrose in drinking water for 6 weeks. AE was intra-peritoneally administered daily at doses of 50,100, and 200 mg/kg for two sequential weeks at the end of the fourth week in metabolic syndrome rats. Twenty-four hours after the last administration of AE, blood was collected and centrifuged, and then the serum was used for the measurement of lipid profile and hepatic enzyme. Serum glucose, insulin, fasting insulin resistance index, body weight, water intake, lipid profile, and hepatic enzymes were significantly increased although food intake was decreased in MS rats compared to the control rats. The lipids and liver enzymes were reduced by AE extracts in the MS group. This study showed that the A. lappa root aqueous extract exhibits a hypolipidemic activity of hyperlipidemic rats. This activity is practically that of a triple-impact antioxidant, hypolipidemic, and hepatoprotective.
Subject(s)
Rats , Sucrose/analysis , Lappa arctium/analysis , Rats, Wistar/classification , Metabolic Syndrome , Liver Function Tests/classificationABSTRACT
BACKGROUND: The Hawthorn (Crateagus sp.) mostly occurs around the temperate region of the world with a high number of species, producing a fruit with numerous beneficial effects for human health. The aim of the study was to determine organic acid and sugar contents in the fruit of a number of hawthorn species grown in Erzincan province of Turkey. RESULTS: Citric acid was the predominant organic acid in all hawthorn species and C. pseudoheterophylla had the highest citric acid content (23.688 g/100 g). There were not statistically significant differences among hawthorn species (except C. atrosanguinea Pojark) in terms of fumaric acid content. C. pontica C.Koch had a higher content of vitamin C (9.418 mg/100 g) compared to other species. Fructose was the predominant sugar component in all species and C. monogyna subsp. monogyna Joiq had the highest fructose content (18.378 g/100 g). CONCLUSIONS: The high fruit quality of the studied species indicates the importance of this fruit in human nutrition as a natural source. The study revealed that there were differences in terms of fruit characteristics among hawthorn species and thus better quality hawthorn genotypes can be selected within the species. Hence, this study is considered to be a valuable reference for forthcoming studies. The high fruit quality of the studied species indicates the importance of this fruit in human nutrition as a natural source.
Subject(s)
Ascorbic Acid/analysis , Citric Acid/analysis , Crataegus/chemistry , Fructose/analysis , Fruit/chemistry , Nutritive Value , Sucrose/analysis , Turkey , Dietary Carbohydrates/analysis , Plant Extracts/analysis , Crops, Agricultural/chemistry , Dicarboxylic Acids/analysis , Glucose/analysisABSTRACT
Sucrose hydrolysis by invertase [EC.3.2.1.26] produces inverted sugar syrup, an ingredient mainly used in the food industry. To properly catalyze hydrolysis, the enzyme should be reused after this reaction. It is advisable to maintain constant activity over a considerable period. Thus, sucrose hydrolysis was performed in a membrane bioreactor - a continuously stirred tank reactor coupled with an ultrafiltration membrane (UFM) which provides good diffusion and high activity per unit volume. Molecular weight cut-off for soluble invertase UFMs was up to 100kDa. This study focused on the role of UFM invertase cut-off as it is the main element in the process. We demonstrated that both the cut-off and chemical nature of the UFM affected specific invertase activity.
A hidrólise da sacarose através da invertase [EC.3.2.1.26] gera xarope de açúcar invertido, que é usado principalmente como ingrediente na indústria alimentícia. Para ter-se uma hidrólise satisfatória, a enzima deve ser reaproveitada após a reação. É desejável que sua atividade seja mantida constante durante um período considerável de reação. A hidrólise da sacarose foi realizada em um reator com membrana (RM) - que é um reator continuamente agitado acoplado a uma membrana de ultrafiltração (MUF) -, porque apresenta efeitos mínimos de difusão e elevada atividade por unidade de volume. O corte molecular da MUF utilizada para reter a invertase solúvel dentro do MR foi de até 100kDa. Como a invertase é o elemento principal deste processo, este trabalho foi focado no papel do corte molecular da MUF na sua atividade. O corte molecular e a natureza química da membrana-UF mostraram afetar a atividade específica da invertase.
Subject(s)
Sucrose/analysis , Membranes , Ultrafiltration/classification , HydrolysisABSTRACT
Levan is an exopolysaccharide of fructose primarily linked by À-(2¨6) glycosidic bonds with some À-(2¨1) branched chains. Due to its chemical properties, levan has possible applications in both the food and pharmaceutical industries. Bacillus subtilis is a promising industrial levan producer, as it ferments sucrose and has a high levan-formation capacity. A new strain of B. subtilis was recently isolated from Japanese food natto, and it has produced levan in large quantities. For future pharmaceutical applications, this study aimed to investigate the effects of levan produced by B. subtilis Natto, mainly as potential hypoglycemic agent, (previously optimized with a molecular weight equal to 72.37 and 4,146 kDa) in Wistar male rats with diabetes induced by streptozotocin and non-diabetic rats and to monitor their plasma cholesterol and triacylglycerol levels. After 15 days of experimentation, the animals were sacrificed, and their blood samples were analyzed. The results, compared using analysis of variance, demonstrated that for this type of levan, a hypoglycemic effect was not observed, as there was no improvement of diabetes symptoms during the experiment. However, levan did not affect any studied parameters in normal rats, indicating that the exopolysaccharide can be used for other purposes.
Subject(s)
Animals , Rats , Bacillus subtilis/isolation & purification , Streptozocin/analysis , Fructans/analysis , Fructose/analysis , Hypoglycemia , Sucrose/analysis , Methodology as a Subject , Rats, WistarABSTRACT
Polyhydroxyalkanoates (PHA) are biodegradable and biocompatible green thermoplastics, synthesized by wide variety of bacteria as an intracellular carbon and energy storage intermediate. They are used as an alternative to nonrenewable petroleum derived plastics. The current interest in these biopolyesters is stimulated by the search for cost-effective capitalized production. This paper attempts to achieve maximized production rate from recombinant system using inexpensive substrate. Molasses from agro-industrial waste was used to produce PHA from recombinant E.coli in batch culture. PHA yield in molasses (3.06g/L ± 0.05-75.5 percent) was higher than that of sucrose (2.5g/L ± 0.05 - 65.1 percent). Properties of the polymer produced from molasses and sucrose were analyzed by DSC, TGA, DTA, GC/MS, TLC and optical rotation studies. The findings suggested that molasses enhanced PHA production in recombinant E.coli.
Subject(s)
Biopolymers/analysis , Escherichia coli Proteins , Molasses/analysis , Pseudomonas , Polyhydroxyalkanoates/analysis , Polymers/analysis , Sucrose/analysis , Biodegradation, Environmental , Methods , MethodsABSTRACT
The aim of this research was to analyze and compare 17 honey samples, 11 organic and six non-organic Apis mellifera honey. The samples were analyzed concerning moisture, hydroxymethylfurfural, diastase index, water activity, color, total sugar, reducing sugar, sucrose, ash, viscosity, electrical conductivity, pH, acidity, and formol index. With the exception of acidity, reducing sugar and diastase index, the averages of other parameters were different between the two groups. All samples of organic honey presented moisture values between 23.50 and 24.40 percent. Among the nonorganic honey samples, two presented apparent sucrose amount upper the maximum limit established by the Brazilian Legislation. According to the quantitative analysis of pollen sediments in the honey samples and frequency of pollen types in 17 honey samples, 41.20 percent were classified as unifioral, and the remainder as polifioral.
O objetivo deste trabalho foi analisar e comparar 17 amostras de Apis mellifera mel, sendo 11 orgânicos e seis não orgânicos. As amostras foram analisadas quanto à umidade, hidroximetilfurfural, índice de diastase, atividade de água, cor, açúcares totais, açúcares redutores, sacarose, cinzas, viscosidade, condutividade elétrica, pH, acidez e índice de formol. Com exceção da acidez, açúcar redutor e índice de diastase as médias dos demais parâmetros analisados diferiram entre os dois grupos. Todas as amostras de mel orgânico analisadas apresentaram valores de umidade entre 23,50 to 24,40 por cento. Das amostras de mel não orgânico analisadas, duas apresentaram quantidades de sacarose aparente acima do limite máximo estabelecido pela legislação brasileira. De acordo com as análises quantitativas dos sedimentos polínicos e a frequência dos tipos polínicos observados nas 17 amostras de mel analisadas, 41,20 por cento foram classificadas como monofloral e o restante como polifloral.
Subject(s)
Animals , Honey/analysis , Pollen/chemistry , Chemical Phenomena , Electric Conductivity , Formaldehyde/analysis , Humidity , Hydrogen-Ion Concentration , Sucrose/analysisABSTRACT
The aim of this study was to create a synthetic juice (SJ) to be used as a surrogate for natural orange juices in erosion studies, verifying its erosive potential. The SJ was formulated based on the chemical composition of orange juices from different locations. Forty enamel and 40 root dentin specimens were randomly assigned into 4 experimental groups (n=10): SJ; 1% Citric Acid (CA); Minute Maid Original® (MM) and Florida Natural Original® (FN). The specimens were immersed in their respective solutions for 5 min, 6x/day for 5 days, in an erosion-remineralization cycling model. Enamel specimens were analyzed by surface Knoop microhardness and optical profilometry and dentin specimens only by optical profilometry. Outcomes were analyzed statistically by ANOVA followed by Tukey’s test considering a significance level of 5%. For enamel, the surface loss and microhardness changes found for MM and SJ groups were similar (p>0.05) and significantly lower (p<0.01) than those found in the CA group. For dentin, CA promoted significantly greater (p<0.01) surface loss compared with all the other groups. No significant difference (p>0.05) was observed in dentin surface loss between MM and SJ. In conclusion, CA was the most erosive solution, and SJ had a similar erosive potential to that of MM natural orange juice.
O objetivo deste estudo foi criar um suco sintético (SJ) para ser usado como substituto do suco de laranja natural em estudos de erosão dental, verificando o seu potencial erosivo. O SJ foi formulado com base na composição química de sucos de laranja de diferentes locais. Quarenta espécimes de esmalte e 40 de dentina radicular foram aleatoriamente alocados em 4 grupos experimentais (n=10): SJ; 1% Citric acid (CA); Minute Maid Original® (MM) e Florida Natural Original® (FN). Os espécimes foram imersos nas suas respectivas soluções por 5 min, 6x/dia por 5 dias, em um modelo de ciclagem de erosão-remineralização. Os espécimes de esmalte foram analisados por microdureza de superfície Knoop e perfilometria ótica, enquanto que os espécimes de dentina foram analisados somente por perfilometria. Os resultados foram analisados estatisticamente com o teste de ANOVA, seguido pelo teste de Tukey, considerando um nível de significância de 5%. Para o esmalte, a perda superficial e as alterações de microdureza encontradas para os grupos MM e SJ foram similares (p>0,05) e significantemente menores (p<0,01) do que as encontradas para o grupo CA. Para dentina, CA promoveu significantemente (p<0,01) a maior perda de superfície quando comparada aos outros grupos. Não foram encontradas diferenças significantes (p>0,05) entre a perda de superfície de dentina dos grupos MM e SJ. Concluiu-se que CA foi a solução mais erosiva e SJ apresentou um potencial erosivo semelhante ao do suco de laranja natural MM.
Subject(s)
Humans , Beverages , Citrus sinensis , Fruit , Tooth Erosion/etiology , Ascorbic Acid/analysis , Beverages/analysis , Chemistry, Pharmaceutical , Calcium/analysis , Citric Acid/analysis , Citric Acid/pharmacology , Citrus sinensis/chemistry , Dental Enamel/drug effects , Dental Enamel/pathology , Dentin/drug effects , Dentin/pathology , Fruit/chemistry , Glucose/analysis , Hardness , Materials Testing , Magnesium/analysis , Phosphorus/analysis , Potassium/analysis , Sucrose/analysis , Time Factors , Tooth RemineralizationABSTRACT
Invertase, whether adsorbed on styrene-divinylbenzene copolymers or otherwise, was used for continuous sucrose hydrolysis using a cell-type membrane reactor (CTMR), coupled with an ultra (UF-100kDa), or a microfiltration (MF- pore diameter of 5 µm) membrane. In all tests, the pH (5.5), temperature (30 ºC), reaction volume (10 mL) and agitation (100 rpm) were set constant; whereas, variable parameters were: feeding rate (0.4, 0.8 and 1.6 h-1), inlet sucrose concentration (2.5, 6.5, 50 and 100 mM) and enzyme/resin ratio (1.64 mg or 3.28 mg of protein per 25, 50 or 100 mg of resin). The best result (yield of 100 percent, steady-state duration over 20h and specific reaction rate over 243 x 10-3 mmol/h.mE) was obtained when insoluble invertase (1.64 mg protein/100 mg resin) was used to convert 50 mM or 100 mM of sucrose solution at 0.4 h-1 using a UF-CTMR.
Invertase, na forma adsorvida ou não em copolímeros de estireno-divinilbenzeno, foi usada para a hidrólise contínua de sacarose utilizando um reator com membrana (RM), acoplado a uma membrana de ultrafiltração (UF-100kDa), ou de microfiltração (MF - um diâmetro de poro de 5µm). Em todos os testes, o pH (5,5), a temperatura (30ºC), o volume reacional (10mL) e a agitação (100 rpm) foram mantidas constantes; os parâmetros variados foram: a vazão de alimentação (0,4; 0,8 e 1,6 h-1), a concentração de sacarose alimentada (2,5; 6,5; 50 e 100 mM) e a relação enzima/resina (1,64 mg ou 3,28 mg de proteína por 25, 50 ou 100 mg de resina). O melhor resultado (um rendimento de 100 por cento, um período de estado estacionário acima de 20h e uma taxa de reação específica maior de 243 x 10-3 mmol/h.mE) foi obtido quando a invertase insolúvel (1,64 mg de proteína/100 de mg resina) foi usado para converter 50 mM ou 100 mM de solução de sacarose a 0,4 h-1 usando UF-RM.
Subject(s)
Membrane Filters/analysis , Hydrolysis , Sucrose/analysis , Enzymes , Food Technology/methodsABSTRACT
Objectives: To determine the pH and sucrose concentrations (SC) of pediatric liquid drugs of long-term use by children in order to evaluate the potential risk for dental caries and dental erosion. Methods: After assessing the pH, we analyzed 71 aqueous medicine samples for sucrose by the Lane-Eynon general volumetric method. The pH and SC values (mean ± standard deviation (SD) were calculated according to therapeutic action. Results: The highest and the lowest SC values (mean ± SD) were found in respiratory (37.75 percent ± 17.23 percent) and endocrine drugs (11.97 percent ± 15.16 percent) (p < 0.01). The values for medicines prescribed for daily ingestion were 47.15 percent ± 9.57 percent, whereas for twice daily and three or four times a day, these numbers were 24.42 percent ± 18.03 percent and 34.43 percent ± 14.83 percent, respectively (p < 0.01). The SC (mean ± SD)) values were higher in syrups (36.32 percent ± 17.62 percent) than in other formulations (p > 0.05). The overall pH (mean ± SD) was 5.89 ± 2.02 (range 2.3 ± 0.01 to 10.6 ± 0.02). In products with acidic pH, the SC (mean ± SD) was significantly lower (22.14 percent ± 15.72 percent) than in nonacidic medicines (39.22 percent ± 15.82 percent) (p < 0.001). Conclusions: It can be concluded that the pediatric medicines studied have a high SC and low pH, which vary according to therapeutic class, daily dose, and brand. Caution about dental caries, dental erosion, and systemic diseases such as diabetes mellitus is warranted when these medicines are ingested frequently.
Objetivos: Determinar el pH y las concentraciones de sacarosa de medicamentos pediátricos líquidos de uso oral a largo plazo, para evaluar el riesgo potencial de caries y erosión dental. Métodos: Se analizaron 71 muestras de medicamentos líquidos; después de evaluar el pH, se determinó la sacarosa por el método volumétrico de Lane&Eynon. El pH y los valores de sacarosa (media ± desviación estándar [DE]) se calcularon de acuerdo con la acción terapéutica. Resultados: El valor de sacarosa más alto (media ± DE) se encontró en los medicamentos respiratorios (37,75 por ciento ± 17,23 por ciento) y el más bajo en los endocrinos (11,97 por ciento 15,16 por ciento ±) (p < 0,01). Los medicamentos recetados para ingerir una vez al día tuvieron valores de 47,15 por ciento ± 9,57 por ciento; los que se administran dos veces al día, 24,42 por ciento ± 18,03 por ciento, y los recetados tres o cuatro veces al día, 34,43 por ciento ± 14,83 por ciento (p < 0,01). Los valores de sacarosa fueron mayores en jarabes (36,32 por ciento ± 17,62 por ciento) que en otras formas farmacéuticas (p > 0,05). El pH general fue 5,89 ± 2,02 (recorrido 2,3 ± 0,01 a 10,6 ± 0,02). La sacarosa fue significativamente inferior en los productos con el pH ácido (22,14 por ciento ± 15,72 por ciento) que en los medicamentos no ácidos (39,22 por ciento ± 15,82 por ciento) (p < 0,001). Conclusiones: Los medicamentos pediátricos estudiados tienen una concentración de sacarosa alta y un pH bajo, los cuales varían según la clase terapéutica, la dosis diaria y la marca. Cuando estos medicamentos se ingieren con frecuencia, se debe tener cuidado con la caries y la erosión dental, así como con las enfermedades sistémicas como la diabetes mellitus.
Subject(s)
Humans , Child , Pharmaceutical Preparations/chemistry , Sucrose/analysis , Administration, Oral , Hydrogen-Ion Concentration , Pharmaceutical Preparations/administration & dosage , Time FactorsABSTRACT
The strain Klebsiella sp. K18 produces the enzyme glucosyltransferase and catalyses the conversion of sucrose to palatinose, an alternative sugar that presents low cariogenicity. Response Surface Methodology was successfully employed to determine the optimal concentration of culture medium components. Maximum glucosyltransferase production (21.78 U mL-1) was achieved using the optimized medium composed by sugar cane molasses (80 g L-1), bacteriological peptone (7 g L-1) and yeast extract (20 g L-1), after 8 hours of fermentation at 28ºC. The conversion of sucrose to palatinose was studied utilizing immobilized cells in calcium alginate. The effects of the alginate concentration (2-4%), cell mass concentration (20-40%) and substrate concentration (25-45%) were evaluated and the yield of palatinose was approximately 62.5%.
A linhagem Klebsiella sp. K18 produz a enzima glicosiltransferase que catalisa a conversão de sacarose em palatinose, um açúcar alternativo que apresenta baixa cariogenicidade. Metodologia de Superfície de Resposta foi empregada com sucesso para determinar a concentração ótima dos componentes do meio de cultivo. A máxima produção deglicosiltransferase (21,78 U mL-1) foi obtida utilizando o meio de cultivo otimizado composto por melaço de cana de açúcar (80 g L-1), peptona bacteriológica (7 g L-1) e extrato de levedura (20 g L-1), após 8 horas de fermentação a 28ºC. A conversão desacarose em palatinose foi estudada utilizando células imobilizadas em alginato de cálcio. Os efeitos da concentração de alginato (2-4%), concentração de massa celular (20-40%) e concentração de substrato (25-45%) foram avaliados e a porcentagem de palatinose foi de aproximadamente 62,5%.
Subject(s)
Alginates , Cariogenic Agents , Fermentation , Glycosyltransferases/analysis , In Vitro Techniques , Klebsiella/enzymology , Molasses/analysis , Sucrose/analysis , Saccharum/enzymology , Chromatography, High Pressure Liquid , Methods , MethodsABSTRACT
For studying the quality of Yemeni green coffee and the impact of environemental and cultural condations, seventeen samples of coffee fruits have been sampled from main regions of coffee productions. Green coffee has been evaluated for chemical characterizations such as water content, caffeine, trigonellin, chlorogenic acids, fat, and sucrose contents. etc. These analysis were conducted in the Chemical Technology Laboratory of CIRAD [Centre de Cooperation International en Recherche Agronomique pour Ie Developpement], Montpellier-France. Areas of production influencing the quality of coffee and non-irrigated coffee in marginal rainfall areas usually show the greatest seasonal quality on coffee quality. The best quality is obtained from selective picking in which only red ripe cherries are gathered, by hand in successive picking rounds until most of the crop has been harvested. High variations of chemical composition of coffee have been observed between samples collected from different regions of coffee production, which reflect the high effects of cultural, post harvesting treatments and climate conditions of coffee growing area on coffee quality. The principal result's of these analysis are presented and discussed in relation to the orighm of samples and the effect of cultural, environmental and possessing conditions on coffee quality. Recommendations and actions to be undertaken in different level of coffee production for preserving and improving coffee quality in Yemen were discussed
Subject(s)
Caffeine/analysis , Sucrose/analysis , Ecological and Environmental PhenomenaABSTRACT
A polyphasic approach was applied to characterize 35 G. diazotrophicus isolates obtained from sugarcane varieties cultivated in Brazil. The isolates were analyzed by phenotypic (use of different carbon sources) and genotypic tests (ARDRA and RISARFLP techniques). Variability among the isolates was observed in relation to the carbon source use preference. Glucose and sucrose were used by all isolates in contrast to myo-inositol, galactose and ribose that were not metabolized. The results of the analysis showed the presence of two groups clustered at 68 percent of similarity. The genetic distance was higher when RISA-RFLP analysis was used. Analysis of 16S rDNA sequences from isolates showed that all of them belonged to the G. diazotrophicus species. Neither effect of the plant part nor sugarcane variety was observed during the cluster analysis. The observed metabolic and genetic variability will be helpful during the strain selection studies for sugarcane inoculation in association with sugarcane breeding programs.
Foi realizado a caracterização polifásica de 35 isolados obtidos de variedades de cana-de-açúcar cultivadas no Brasil, através de testes fenotípicos (uso de fontes diferentes de carbono) e genotípicos (técnicas de ARDRA e RISA-RFLP). Houve variação entre os isolados com relação à utilização de fontes de carbono. Glicose e sacarose foram usadas por todos isolados, diferentemente de mio-inositol, galactose e ribose que não foram metabolizados. Os resultados da análise polifásica dos dados confirmam a formação de dois grupos, que apresentaram 68 por cento de similaridade. Observou-se maior distância genética entre os isolados quando a técnica de RISA-RFLP foi aplicada. O sequênciamento da região 16S do rDNA mostrou que todos os isolados pertencem à espécie G. diazotrophicus. Não foi observado efeito da parte da planta ou variedade de cana-de-açúcar no agrupamento dos isolados. Em conjunto, esses resultados poderão auxiliar no estudo de seleção de estirpes para inoculação em cana-de-açúcar, orientando programas de melhoramento vegetal.
Subject(s)
Genetic Variation , Gluconacetobacter/genetics , Gluconacetobacter/isolation & purification , Glucose/analysis , Herb-Drug Interactions , In Vitro Techniques , Nitrogen Fixation , Phenotype , Sucrose/analysis , Methods , Saccharum , Serial Passage , MethodsABSTRACT
Se determinó la presencia de plomo en muestras de azúcar de caña de procedencia nacional, mediante un nuevo ensayo por espectrofotometría de Absorción Atómica Electrotérmica (EAAE). Se utilizaron dos métodos espectrofotométricos, el método de espectrofotometría de Absorción Atómica de Flama (EAAF) y el electrotérmico, para determinar la sensibilidad de ambos métodos en la cuantificación de plomo en caña de azucar.
Subject(s)
Lead Poisoning , Lead/analysis , Sucrose/analysis , Saccharum/adverse effectsABSTRACT
A conversão do amido, armazenado nas frutas durante seu desenvolvimento, em açúcares, é desempenhada por várias enzimas, constituindo-se em um dos principais processos do amadurecimento. A função das enzimas hidrolíticas, 'alfa'-amilase e 'beta'-amilase, no metabolismo amido-sacarose durante o amadurecimento de bananas, foi avaliada através da determinação dos perfis de transcrição e tradução dos seus genes. Utilizando-se da expressão heteróloga de clones de cDNA das amilases, foi possível obter as proteínas recombinantes, inclusive na sua forma enzimaticamente ativa, bem como induzir a produção de anticorpos policlonais em coelhos, com os quais pode-se acompanhar a variação nos níveis de expressão de cada uma das duas enzimas. O tratamento de bananas com o hormônio etileno induziu a antecipação dos processos de degradação do amido e síntese de açúcares. em relação ao grupo de frutas controle. Enquanto no grupo controle, as variações nos níveis de proteína e transcrição relativos à 'alfa'-amilase sugerem que há redução na expressão do gene, no grupo tratado com etileno não foi possível detectar a expressão da proteína, apesar dos incrementos na transcrição e atividade. Tal fato pode ser associado à degradação do grânulo de amido e conseqüente solubilização de proteínas ligadas à sua superfície e ao provável aumento no turnover de proteínas promovidos pelo etileno. Em resposta ao tratamento com etileno, houve antecipação dos picos de atividade relacionados especificamente com a 'beta'-amilase, o mesmo ocorreu na detecção do transcrito e sua proteína. Tais resultados, sugerem que em bananas, os padrões de expressão e atividade da 'beta'-amilase estão diretamente relacionados à degradação do amido, respondendo também às variações hormonais na fruta, não sendo possível afirmar o mesmo para 'alfa'-amilase...
Subject(s)
Amylases , Starch/metabolism , Cloning, Molecular , Food Chemistry , Sucrose/analysis , Zingiberales , Molecular Biology/methods , Transcription, GeneticABSTRACT
Protocormos in vitro de Phalaenopsis de tres meses de edad se transfirieron a contenedores RITA® con el fin depropagarlos masivamente. Los factores evaluados fueron la concentración de sacarosa en el medio y la frecuencia de inmersión. Se dispusieron cinco pares de contenedores RITA® con medio de cultivo líquido a concentraciones de sacarosa de 0, 15, 30, 45 y 60 g/L. El medio utilizado fue el MS a la mitad de la concentración de las sales, suplementado con vitaminas y tidiazuron (5 mg/L). El experimento se realizó en dos etapas, cada una con duración de dos meses. La primera etapa con una frecuencia de inmersión de cuatro horas y la segunda con una frecuencia de inmersión de ocho horas, ambas con un tiempo de inmersión de un minuto. Los resultados mostraron que la mejor respuesta proliferativa, con 8,2 protocormos adventicios por protocormo por mes, se obtuvo en el medio con 15 g/L de sacarosa y un tiempo de inmersión de un minutocada cuatro horas.
In order to massively propagate Phalaenopsis orchids, three months old in vitro protocorms were transferred to RITA® vessels. The evaluation factors were the sucrose concentration in the culture medium and the frequency immersion. There was a set of five pairs of RITA® vessels with liquid culture medium containing sucrose at 0, 15, 30, 45, 60 g/L. A half-strength MS medium plus vitamins, supplemented with vitamins and thidiazuron (5 mg/L) was used. The experiment had two stages, each lasting two months. Each stage had a one minute immersion. The first stage had a four hour immersion frequency and the second one had an eight hour immersion frequency. Results showed that the best proliferating response was reached in a 15 g/L of sucrose medium with one minute of immersion time every four hours, resulting in 8,2 adventitious protocorms per protocorm per month.
Subject(s)
Immersion , Orchidaceae/growth & development , Sucrose/analysis , Sucrose/adverse effectsABSTRACT
Magnetic Resonance Imaging (MRI) was employed to monitor changes in image intensities in stems of sugarcane which reflect on the increase in sucrose concentration. Contrast in images originates in the increase of sucrose concentration in the aqueous phase of the predominant parenchyma cells and physiological changes. In matured stems mixed MR intensity patterns were observed in transverse planes. We associate this due to the reflection of vascular bundles in ground parenchyma cells which constitute 80% sucrose storage.
Subject(s)
Magnetic Resonance Imaging , Poaceae/chemistry , Sucrose/analysisABSTRACT
Selecionou-se e treinou-se uma equipe de 10 julgadores capazes de avaliar a doçura, empregando a técnica de tempo-intensidade. Por meio da técnica de escala relativa foram determinadas as concentraçöes de 7 substâncias doces equivalentes em doçura soluçäo de 5 por cento de sacarose, obtendo-se as seguintes intensidades relativas: 1 para a sacarose, 11 para frutose, 0,5 para o sorbitol, 0,3 para a lactose, 129 para o aspartame, 23 para o ciclamato e 144 para o esteviosídeo. Com a soluçäo de de 0,034 por cento de esteviosídeo equivalente em doçura à soluçäo de 5 por cento de sacarose estudou-se a qualidade de doçura por meio da técnica tempo-intensidade. O esteviosídeo apresentou curva de intensidade de doçura em funçäo do tempo semelhante da sacarose e sabor residual doce mais persistente. Este resultado vem mostrar que a equipe do ITAL é capaz de fornecer resposta semelhante àquela descrita na literatura viabilizando o uso da técnica tempo-intensidade
Subject(s)
Sucrose/analysis , Taste , Time Factors , Sucrose/chemistryABSTRACT
O esvaziamento gástrico (EG) de soluçöes de sacarose e de maltose em diferentes concentraçöes, marcadas com fenol vermelho (6mg por cento), foi determinado em 144 ratos Wistar machos. Foi avaliada a retençäo gástrica (RG), após 15 minutos da infusäo orogástrica, de soluçöes de sacarose e de maltose nas concentraçöes de 2,5 por cento, 5 por cento e 10 por cento, empregado inicialmente 1 ml e noutra observaçäo 2 ml/100 g de peso do animal. Para cada volume e concentraçäo foram utilizados 12 animais. Foram determinadas as atividades das dissacridases, lactase, sacarase e maltase no intestino delgado de outros oito ratos Wistar machos, submetidos às mesmas condiçöes do estudo. Os resultados mostrarom uma relaçäo da atividade da maltose com a da atividade da maltose com a da sacarose de 4:1. Por outro lado, a RG das soluçöes de maltose a 5 por cento e 10 por cento foi significativamente maior que a de sacarose nas mesmas concentraçöes, independente do volume utilizado. Em concentraçäo a 2,5 por cento näo houve diferença significativa entre as RG das duas soluçöes. Para explicar os resultados, é proposto que o EG mais rápido da soluçäo de sacarose nas concentraçöes a 5 por cento e 10 por cento comparado à soluçäo de maltose nas mesmas concentraçöes, resulta de uma possível saturaçäo da sacarose, com interrupçäo na regulaçäo do EG, gerada a partir de receptores intestinais
Subject(s)
Rats , Animals , Male , Disaccharidases/analysis , Gastric Emptying/physiology , Intestinal Mucosa/physiology , Maltose/analysis , Sucrose/analysis , Intestinal Mucosa/enzymology , Rats, WistarABSTRACT
Dentre 16 cepas de fungos testados, foram selecionadas 4 cepas como melhores produtoras da atividade sacarose fosforitase.Scytalidium sp e Colletotrichum gloesporioides apresentaram atividade sacarose fosforitase predominantemente intracelular, enquanto que em Sclerotinia sclerotiorum e Monilia sitophila, a atividade foi predominante extracellular.Altos valores de temperatura ótimas 50ºC e 40ºC foram encontrados respectivamente para a enzima de M.sitophila e para as outras 3 cepas selecionadas.Como sacarose fosforilase de M.sitophila foi a mais termoestável, retendo 90-95 por cento de sua atividade fosforolítica inicial após pré-tratamento na ausência de substrato, a 50ºC-70ºC durante 30 minutos, ela foi selecionada para estudos posteriores.A maior produçäo da enzima (340 UI/L de meio cultivado ou 0, 336 UI/mg de proteínas) foi obtida no início da fase estacionária de crescimento da M.sitophila cultivada em extrato de inhame com 0, 15 por cento de sulfato de amônio, à temperatura ambiente(28ºC-30ºC) e agitaçäo continua.Foram afetuados estudos preliminares de imobilizaçäo do extrato bruto da sacarose fosforilase, por adsorçäo em DEAE-celulose e ligaçäo covalente em quitosana.o melhor resultado foi obtido com o derivado imobilizado em quitosana o qual reteve 12 por cento de proteínas e 216 por cento da atividade específica inicial