RESUMO

The acidity of a solution is associated with the concentration of Brønsted acids. This work proposes a new non-titrimetric potentiometric method using citrate buffer for the determination of vinegar acidity. The difference between the pH values before and after the addition of a diluted vinegar sample to 10 mmol L-1 citrate buffer (pH 5.5) was related to the acetic acid concentration. The dynamic range of the quadratic analytical curve was from 3.5 to 20 mmol L-1 (R2 = 0.998). The repeatability was 0.8% for acetic acid at 0.01 mol L-1. Comparison with the conventional titration method showed an error between 0.7% and 4.64% (n = 9) for analysis of commercial vinegar samples The behaviour of the system could be explained using the buffering function.

Assuntos

RESUMO

Host plant selection by herbivores is driven by a complex array of cues, including leaf traits and previous leaf damage. Herbivore-associated cues to host selection at the plant and leaf scale aid understanding of mechanisms responsible for host preference that might translate into increased performance, as well as processes structuring herbivore populations mediated by interactions. We investigated how changes induced by a galling insect in the tropical fern Cyathea phalerata act as repellent or attractant cues for sawfly feeding and the effects of leaf size on herbivory levels. We recorded gall abundance, damage by chewers, leaf size, plant nutritional quality, phenolic concentration and leaf anatomical traits between galled and non-galled leaf samples. Galled samples contained less N, higher levels of phenolics and higher C/N ratio. However, leaf-chewing damage did not differ between galled and non-galled leaves. The gall structure was avoided by chewers, as it had high concentrations of phenolics, lignification and suberization. Larger leaves sustained higher gall abundance, but leaf size did not have a significant effect on chewer damage. A co-occurrence index calculated for both guilds indicated that galls and chewers exhibited a distribution that did not differ from random, reinforcing that the two guilds on C. phalerata do not show patterns of repulsion such as those maintained by interspecific competition. Sawflies dismissing chemical cues indicate that the increase in phenolics caused by galling insects does not generate increased protection of the galled pinnules. Our results highlight ferns as key resources for herbivores and as a potential plant group to study new research avenues on plant-insect interactions.

Assuntos

RESUMO

Abstract Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.

Resumo Vinte e três linhagens bacterianas degradadoras de hidrocarbonetos foram isoladas de água subterrânea contaminada por vazamento em posto de combustível no sul da Amazônia, Brasil. Com base na habilidade de degradar hidrocarbonetos (diesel, hexadecano, benzeno, tolueno e xileno), duas linhagens foram selecionadas para estudos posteriores. A amplificação e sequenciamento do gene 16S rRNA demonstrou que essas linhagens pertencem ao gênero Bacillus (Bacillus sp. L26 and Bacillus sp. L30). Análises de GC-MS mostraram que a linhagem L30 foi mais eficiente em degradar n-alcanos (C10-C27) presentes no diesel, após 7 dias de cultivo em meio mineral. Ambas as linhagens produziram biossurfactantes e apresentaram atividade emulsificante, especialmente a linhagem L30. O gene alcano hidroxilase (grupo III), o qual é importante para degradação de alcanos, foram detectados nas linhagens. Como resultado, este estudo indicou que essas linhagens bacterianas podem ser promissoras se aplicadas em processos de biorremediação.

Assuntos

RESUMO

Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.

Assuntos

RESUMO

Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.(AU)

Vinte e três linhagens bacterianas degradadoras de hidrocarbonetos foram isoladas de água subterrânea contaminada por vazamento em posto de combustível no sul da Amazônia, Brasil. Com base na habilidade de degradar hidrocarbonetos (diesel, hexadecano, benzeno, tolueno e xileno), duas linhagens foram selecionadas para estudos posteriores. A amplificação e sequenciamento do gene 16S rRNA demonstrou que essas linhagens pertencem ao gênero Bacillus (Bacillus sp. L26 and Bacillus sp. L30). Análises de GC-MS mostraram que a linhagem L30 foi mais eficiente em degradar n-alcanos (C10-C27) presentes no diesel, após 7 dias de cultivo em meio mineral. Ambas as linhagens produziram biossurfactantes e apresentaram atividade emulsificante, especialmente a linhagem L30. O gene alcano hidroxilase (grupo III), o qual é importante para degradação de alcanos, foram detectados nas linhagens. Como resultado, este estudo indicou que essas linhagens bacterianas podem ser promissoras se aplicadas em processos de biorremediação.(AU)

Assuntos

RESUMO

This study analyzes the lipid composition and the oxidative stability of oils of Sapindaceae and Meliaceae seeds. The oil content ranged from 14.7% (Guarea guidonia) to 30.1% (Allophylus puberulus and Paullinia elegans). Ten fatty acids were identified in seed oils. Guarea guidonia seeds accumulated mainly oleic (44.9%) and linoleic (24.1%) acid, whereas the unusual gondoic and paullinic acids were identified in A. puberulus (15.8%; 8.9%) and P. elegans (14.4%; 44.2%), respectively. The oil of P. elegans had the highest oxidative stability (16.2 h.). Tocopherol predominated in A. puberulus (10.4 mg/100 g) and tocotrienol predominated in G. guidonea and P. elegans (2.6 mg/100 g). The vitamers α-tocopherol, γ-tocopherol, and γ-tocotrienol were found in the studied oils. ß-carotene was predominantly detected in the oil of A. puberulus seeds (22.4 µg/g). Guarea guidonia seed oil has a high potential in food due to richness in essential fatty acids. In turn, A. puberulus and P. elegans oils could be suggested for other industrial purposes (e.g., biodiesel, varnishes, paints, soaps, or oleochemicals) due to their content of long-chain fatty acids.

RESUMO

Abstract Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.

Resumo Vinte e três linhagens bacterianas degradadoras de hidrocarbonetos foram isoladas de água subterrânea contaminada por vazamento em posto de combustível no sul da Amazônia, Brasil. Com base na habilidade de degradar hidrocarbonetos (diesel, hexadecano, benzeno, tolueno e xileno), duas linhagens foram selecionadas para estudos posteriores. A amplificação e sequenciamento do gene 16S rRNA demonstrou que essas linhagens pertencem ao gênero Bacillus (Bacillus sp. L26 and Bacillus sp. L30). Análises de GC-MS mostraram que a linhagem L30 foi mais eficiente em degradar n-alcanos (C10-C27) presentes no diesel, após 7 dias de cultivo em meio mineral. Ambas as linhagens produziram biossurfactantes e apresentaram atividade emulsificante, especialmente a linhagem L30. O gene alcano hidroxilase (grupo III), o qual é importante para degradação de alcanos, foram detectados nas linhagens. Como resultado, este estudo indicou que essas linhagens bacterianas podem ser promissoras se aplicadas em processos de biorremediação.

RESUMO

BACKGROUND: Normal B lymphoid maturation occurs in bone marrow (BM) throughout life, but immature B-cell progenitors (BCPs) are more numerous in children than in adults. To assess the normal values according to age became important as BCPs are decreased in myelodysplastic syndromes and have been considered an important diagnostic and prognostic feature in these clonal disorders. METHODS: in a multicenter retrospective study from the Brazilian Group of Flow Cytometry we analyzed the variation of BCPs in normal BM according to age and technical peculiarities of each laboratory. We analysed of 45 BM donors and 89 cases examined for elucidation of transitory reactive cytopenias presenting a normal BM immunophenotyping. BCPs were enumerated as CD19+ /CD34+ /CD45dim /CD10+ cells (panel 1) or CD19+ /CD34+ /CD45dim cells (panel 2) among the total nucleated non-erythroid cells and as percentage of CD34+ cells. RESULTS: we included 134 cases. Panel 1 was applied in 88 cases and panel 2 was used in 46. Age range: 10 months to 89 years. In a multiple regression, % BCPs/total nucleated cells was an exponential function of age. Age explained alone 49.4% of the variance, while 'panel used' explained 1.8% and 'laboratory' explained 0.7%. Age explained only 24.9% of the variance of BCPs/CD34+ cells. CONCLUSIONS: in normal individuals, BM B-cell precursors varied mainly according to age, but were also dependent on technical peculiarities of operators and equipments. Analysis by phenotype and as percentage of total nucleated cells was more accurate and less susceptible to variation than evaluating % BCPs/total CD34+ cells. © 2017 International Clinical Cytometry Society.

Assuntos

RESUMO

Abstract Twenty-three hydrocarbon-degrading bacteria strains were isolated from gas station leaking-contaminated groundwater located in the Southern Amazon, Brazil. Based on hydrocarbon (diesel, hexadecane, benzene, toluene and xylene) degradation ability, two strains were selected for further study. The amplification and sequencing of the 16S rRNA gene showed that these two strains belonged to the genus Bacillus (Bacillus sp. L26 and Bacillus sp. L30). GC-MS analysis showed that strain L30 was the most effective in degrading n-alkane (C10-C27) from diesel after 7 days of cultivation in mineral medium. Both strains produced biosurfactants and showed emulsification activity, specially the strain L30. Alkane hydroxylase gene (group III), which is important for alkane biodegradation, was present in strains. As a result, this study indicated that these bacteria could have promising applications in hydrocarbon bioremediation.

Resumo Vinte e três linhagens bacterianas degradadoras de hidrocarbonetos foram isoladas de água subterrânea contaminada por vazamento em posto de combustível no sul da Amazônia, Brasil. Com base na habilidade de degradar hidrocarbonetos (diesel, hexadecano, benzeno, tolueno e xileno), duas linhagens foram selecionadas para estudos posteriores. A amplificação e sequenciamento do gene 16S rRNA demonstrou que essas linhagens pertencem ao gênero Bacillus (Bacillus sp. L26 and Bacillus sp. L30). Análises de GC-MS mostraram que a linhagem L30 foi mais eficiente em degradar n-alcanos (C10-C27) presentes no diesel, após 7 dias de cultivo em meio mineral. Ambas as linhagens produziram biossurfactantes e apresentaram atividade emulsificante, especialmente a linhagem L30. O gene alcano hidroxilase (grupo III), o qual é importante para degradação de alcanos, foram detectados nas linhagens. Como resultado, este estudo indicou que essas linhagens bacterianas podem ser promissoras se aplicadas em processos de biorremediação.

RESUMO

Foi conduzido um ensaio de digestibilidade para determinar o valor nutritivo do resíduo desidratado de cervejaria (RDC) e outro para verificar o desempenho de coelhos em crescimento alimentados com rações contendo diferentes níveis de RDC e a viabilidade econômica da utilização do RDC. No ensaio de digestibilidade, foram utilizados 20 coelhos, de ambos os sexos, da raça Nova Zelândia Branco, com idade média de 45 dias, distribuídos em delineamento experimental inteiramente ao acaso, com dois tratamentos, sendo uma dieta referência e outra dieta teste, na qual o RDC substituiu a ração referência em nível de 30%. Os coeficientes de digestibilidade aparente (CDA) da matéria seca (MS), da energia bruta (EB), da proteína bruta (PB) do RDC foram de 49,97%, 49,34%, e 71,06%, respectivamente, com valores de energia digestível (ED) e proteína digestível (PD) do RDC, com base na matéria seca, de 2330,60kcal/kg e 15,75%. No experimento de desempenho, foram avaliadas rações com níveis de inclusão de RDC de 0%, 5%, 10%, 15%, 20% e 25%. Foram utilizados 120 coelhos da raça Nova Zelândia Branco, 60 machos e 60 fêmeas, com 32 dias de idade, em delineamento experimental inteiramente ao acaso, com seis tratamentos e 10 repetições, sendo a unidade experimental constituída por dois animais. Não foram observadas diferenças no desempenho dos coelhos alimentados com ração contendo níveis crescentes de RDC, exceto para a conversão alimentar aos 70 dias, que apresentou efeito quadrático no período dos 32 aos 70 dias de idade, com a pior conversão alimentar ao nível de 16,95% de RDC. No entanto, houve redução linear nos custos com alimentação, por quilo de ganho de peso dos animais. Conclui-se que o resíduo desidratado de cervejaria apresenta CDA equivalente aos ingredientes convencionais, podendo ser incluído até o nível máximo estudado de 25% nas rações de coelhos em crescimento, sem prejudicar o desempenho.(AU)

Two experiments were conducted, being a digestibility assay in order to determine the nutritive value of dehydrated diets containing different levels of DBR, and the economic viability of the use of DRC brewer residue (DBR) and other assays to verify the performance of growing rabbits fed. In the digestibility experiment, twenty White New Zealand rabbits were used, with an average age of 45 days, of both genders, distributed in a completely randomized design with four treatments, one reference diet and other test diets, in which the DBR replaced the basal diet at 30% level. The apparent digestibility coefficients (ADC) of dry matter (DM), gross energy (GE), crude protein (CP) of DBR were, respectively, 49.97%, 49.34% and 71.06%. The values of digestible energy (DE) and digestible protein (DP) of the DBR, based on dry matter, were 2330.60kcal/kg and 15.75%. In the performance experiment, diets with levels of DBR inclusion of 0%, 5%, 10%, 15%, 20% and 25% were evaluated. One hundred and twenty 32 days old New Zealand White rabbits were used, being 60 males and 60 females, distributed in a completely randomized design with six treatments and ten replicates, and the experimental unit consisted of two animals. No differences (P>0.05) were observed in the performance of rabbits fed diets containing increasing levels of dehydrated brewer residue, except for feed conversion at 70 days which presented a quadratic effect, with the worst results at the level of 16.95% of the DBR inclusion in the diet. It is concluded that the dehydrated brewer residue has good nutritional value and can be included up to the maximum level studied of 25% in the diets of growing rabbits, with no damage to its performance.(AU)

Assuntos