Contextualized Class Improves Perception of Students About Spectrophotometry in Biochemistry Laboratory Practices

Practical work in the laboratory occupies a considerable proportion of students’ time in Pharmacy courses. Thus, it is vital for students who are taking courses in health science to experience handling practices thinking about its practical application. However, students have difficulty in correlating the knowledge acquired in other disciplines - especially, Analytical Chemistry - to Biochemistry. Here, we use an existing laboratory practice and contextualized it using a case-oriented examination and a dynamic discussion about spectrophotometry as a routine analysis in scientific research. With this goal, a group of students was submitted to a traditional practical class (control group, n= 65) while another one was submitted to an contextualized practical class (experimental group, n= 30). After a practical test, the scores of both groups were compared to each other. The results suggested that the contextualization of the practical classes could provide conditions to obtain technical competence of the students, increasing their comprehension about the relevance of interdisciplinary concepts and its applications.As aulas práticas ocupam uma considerável proporção do tempo dos estudantes do curso de Farmácia. Assim, torna-se vital que os alunos dos cursos de saúde participem de aulas laboratoriais que os remetam a uma aplicação prática. Entretanto, os estudantes têm dificuldade em correlacionar o conhecimento adquirido em outras disciplinas - especialmente Química Analítica - com Bioquímica. Neste trabalho, utilizou-se uma aula prática existente (tradicional) e uma aula prática contextualizada com um caso clínico, seguida de uma orientação dinâmica sobre espectrofotometria como análise de rotina em pesquisa científica. Com este objetivo, um grupo de estudantes foi submetido à aula prática tradicional (grupo controle, n= 65) enquanto outro foi submetido à aula prática contextualizada (grupo experimental, n= 30). Após a avaliação prática, as pontuações de ambos os grupos foram comparadas entre si. Os resultados sugerem que a contextualização das aulas práticas fornece condições para que os alunos adquiram competência técnica, aumentando sua compreensão acerca da relevância de conceitos interdisciplinares e suas aplicações

Characterization of Rubus fruticosus mitochondria and salicylic acid inhibition of reactive oxygen species generation at Complex III/Q cycle: potential implications for hypersensitive response in plants

In addition to adenosine triphosphate (ATP) production, mitochondria have been implicated in the regulation of several physiological responses in plants, such as programmed cell death (PCD) activation. Salicylic acid (SA) and reactive oxygen species (ROS) are essential signaling molecules involved in such physiological responses; however, the mechanisms by which they act remain unknown. In non-photosynthesizing tissues, mitochondria appear to serve as the main source of ROS generation. Evidence suggests that SA and ROS could regulate plant PCD through a synergistic mechanism that involves mitochondria. Herein, we isolate and characterize the mitochondria from non-photosynthesizing cell suspension cultures of Rubus fruticosus. Furthermore, we assess the primary site of ROS generation and the effects of SA on isolated organelles. Mitochondrial Complex III was found to be the major source of ROS generation in this model. In addition, we discovered that SA inhibits the electron transport chain by inactivating the semiquinone radical during the Q cycle. Computational analyses confirmed the experimental data, and a mechanism for this action is proposed.CAPESCNPqFAPES

Biochemical traits useful for the determination of genetic variation in a natural population of Myracrodruon urundeuva

Os objetivos deste trabalho foram analisar sementes de 20 árvores de aroeira (Myracrodruon urundeuva Fr. All.) de uma mesma população na região de Selvíria, MS, quanto ao seu conteúdo de proteínas, lipídios e carboidratos, e os níveis de variação genética existentes em relação a esses compostos. O delineamento experimental usado foi o inteiramente casualizado com 20 tratamentos (famílias) e duas repetições. Foram detectados quatro tipos de proteínas: albumina (35,0 a 107,3 mg/g de semente); globulina (3,4 a 9,3 mg/g); prolamina (60,0 a 135,2 mg/g) e glutelina (118,0 a 286,0 mg/g). Os teores lipídicos apresentaram uma variação de 200 a 334 mg/g de semente. Os açúcares totais apresentaram uma variação de 26,5 a 46,3 mg/g de semente, com predominância dos polióis: arabinitol, manitol, glucitol e xilitol. Os principais carboidratos detectados foram glicose e arabinose. A hidrólise total dos açúcares indicou a presença de arabinana neutra e oligossacarídeos de xilana. O conteúdo de amido variou entre 0,35 e 1,58 mg/g de semente. Os caracteres bioquímicos estudados mostraram grande variabilidade genética, indicando que a coleta de sementes em várias árvores constitui uma amostragem mais representativa da população, tanto para fins de conservação como para o melhoramento genético.The objectives of this work were to analyze seeds from 20 trees of aroeira (Myracrodruon urundeuva Fr. All.) of a natural population located in the region of Selvíria, State of Mato Grosso do Sul, Brazil, in order to evaluate their protein, lipid and carbohydrate contents, and to estimate their genetic variation. A completely randomized experimental design consisting of 20 treatments (families) was set up, with two replications. Four types of proteins were detected: albumin (35.0 to 107.3 mg/g seed), globulin (3.4 to 9.3 mg/g), prolamin (60.0 to 135.2 mg/g) and glutelin (118.0 to 286.0 mg/g). The lipid content varied between 200 and 334 mg/g seed. The total sugars also varied (26.5 to 46.3 mg/g seed), with a predominance of polyols (arabinitol, mannitol, glucitol and xylitol). The main monosaccharides detected were glucose and arabinose. Total hydrolysis of the sugars indicated the presence of neutral arabinan and xylan oligosaccharides. The starch content varied from 0.35 to 1.58 mg/g seed. These biochemical traits showed considerable genetic variability, indicating that only the collection of seeds from many different trees can provide a representative sample of the population for conservation and genetic improvement

Biochemical traits useful for the determination of genetic variation in a natural population of Myracrodruon urundeuva

Os objetivos deste trabalho foram analisar sementes de 20 árvores de aroeira (Myracrodruon urundeuva Fr. All.) de uma mesma população na região de Selvíria, MS, quanto ao seu conteúdo de proteínas, lipídios e carboidratos, e os níveis de variação genética existentes em relação a esses compostos. O delineamento experimental usado foi o inteiramente casualizado com 20 tratamentos (famílias) e duas repetições. Foram detectados quatro tipos de proteínas: albumina (35,0 a 107,3 mg/g de semente); globulina (3,4 a 9,3 mg/g); prolamina (60,0 a 135,2 mg/g) e glutelina (118,0 a 286,0 mg/g). Os teores lipídicos apresentaram uma variação de 200 a 334 mg/g de semente. Os açúcares totais apresentaram uma variação de 26,5 a 46,3 mg/g de semente, com predominância dos polióis: arabinitol, manitol, glucitol e xilitol. Os principais carboidratos detectados foram glicose e arabinose. A hidrólise total dos açúcares indicou a presença de arabinana neutra e oligossacarídeos de xilana. O conteúdo de amido variou entre 0,35 e 1,58 mg/g de semente. Os caracteres bioquímicos estudados mostraram grande variabilidade genética, indicando que a coleta de sementes em várias árvores constitui uma amostragem mais representativa da população, tanto para fins de conservação como para o melhoramento genético.The objectives of this work were to analyze seeds from 20 trees of aroeira (Myracrodruon urundeuva Fr. All.) of a natural population located in the region of Selvíria, State of Mato Grosso do Sul, Brazil, in order to evaluate their protein, lipid and carbohydrate contents, and to estimate their genetic variation. A completely randomized experimental design consisting of 20 treatments (families) was set up, with two replications. Four types of proteins were detected: albumin (35.0 to 107.3 mg/g seed), globulin (3.4 to 9.3 mg/g), prolamin (60.0 to 135.2 mg/g) and glutelin (118.0 to 286.0 mg/g). The lipid content varied between 200 and 334 mg/g seed. The total sugars also varied (26.5 to 46.3 mg/g seed), with a predominance of polyols (arabinitol, mannitol, glucitol and xylitol). The main monosaccharides detected were glucose and arabinose. Total hydrolysis of the sugars indicated the presence of neutral arabinan and xylan oligosaccharides. The starch content varied from 0.35 to 1.58 mg/g seed. These biochemical traits showed considerable genetic variability, indicating that only the collection of seeds from many different trees can provide a representative sample of the population for conservation and genetic improvement.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq

Increased Malbranchea pulchella β-glucosidase production and its application in agroindustrial residue hydrolysis: A research based on experimental designs

β-Glucosidases are a limiting factor in the conversion of cellulose to glucose for the subsequent ethanol production. Here, β-glucosidase production by Malbranchea pulchella was optimized using Composite Central Designs and Response Surface Methodologies from a medium designed. The coefficient of determination (R2) was 0.9960, F-value was very high, and the lack of fit was found to be non-significant. This indicates a statistic valid and predictive result. M. pulchella enzymatic extract was successfully tested as an enzymatic cocktail in a mixture design using sugarcane bagasse, soybean hull and barley bagasse. We proved that the optimization of the β-glucosidase production and the application in hydrolysis using unexpansive biomass and agricultural wastes can be accomplished by means of statistical methodologies. The strategy presented here can be useful for the improvement of enzyme production and the hydrolysis process, arising as an alternative for bioeconomy

Characterization of a novel sugar transporter involved in sugarcane bagasse degradation in Trichoderma reesei

Abstract Background Trichoderma reesei is a saprophytic fungus implicated in the degradation of polysaccharides present in the cell wall of plants. T. reesei has been recognized as the most important industrial fungus that secretes and produces cellulase enzymes that are employed in the production of second generation bioethanol. A few of the molecular mechanisms involved in the process of biomass deconstruction by T. reesei; in particular, the effect of sugar transporters and induction of xylanases and cellulases expression are yet to be known. Results In our study, we characterized a novel sugar transporter, which was previously identified by our group through in silico analysis of RNA-seq data. The novel T. reesei 69957-sugar transport system (Tr69957) is capable of transporting xylose, mannose, and cellobiose using a T. reesei 69957-sugar transport system in Saccharomyces cerevisiae. The deletion of Tr69957 in T. reesei affected the fungal growth and biomass accumulation, and the sugar uptake in the presence of mannose, cellobiose, and xylose. Molecular docking studies revealed that Tr69957 shows reduced protein–ligand binding energy for interactions towards disaccharides in comparison with monosaccharides. Furthermore, the deletion of Tr69957 affected the gene expression of cellobiohydrolases (cel7a and cel6a), β-glucosidases (cel3a and cel1a), and xylanases (xyn1 and xyn2) in the cultures of parental and mutant strains in the presence of cellobiose and sugarcane bagasse (SCB). Conclusion The transporter Tr69957 of T. reesei can transport cellobiose, xylose, and mannose, and can affect the expression of a few genes encoding enzymes, such as cellulases and xylanases, in the presence of SCB. We showed for the first time that a filamentous fungus (T. reesei) contains a potential mannose transporter that may be involved in the degradation of cellulose

Comparison of <i>Trichoderma longibrachiatum</i> Xyloglucanase Production Using Tamarind (<i>Tamarindus indica</i>) and Jatoba (<i>Hymenaea courbaril</i>) Seeds: Factorial Design and Immobilization on Ionic Supports

Xyloglucan (XG) is the predominant hemicellulose in the primary cell wall of superior plants. It has a fundamental role in controlling the stretching and expansion of the plant cell wall. There are five types of enzymes known to cleave the linear chain of xyloglucan, and the most well-known is xyloglucanase (XEG). The immobilization process can be used to solve problems related to stability, besides the economic benefits brought by the possibility of its repeated use and recovery. Therefore, this study aims at the optimization of the xyloglucanase production of Trichoderma longibrachiatum using a central composite rotatable design (CCRD) with tamarind and jatoba seeds as carbon sources, as well as XEG immobilization on ionic supports, such as MANAE (monoamine-N-aminoethyl), DEAE (diethylaminoethyl)-cellulose, CM (carboxymethyl)-cellulose, and PEI (polyethyleneimine). High concentrations of carbon sources (1.705%), at a temperature of 30 °C and under agitation for 72 h, were the most favorable conditions for the XEG activity from T. longibrachiatum with respect to both carbon sources. However, the tamarind seeds showed 23.5% higher activity compared to the jatoba seeds. Therefore, this carbon source was chosen to continue the experiments. The scaling up from Erlenmeyer flasks to the bioreactor increased the XEG activity 1.27-fold (1.040 ± 0.088 U/mL). Regarding the biochemical characterization of the crude extract, the optimal temperature range was 50–55 °C, and the optimal pH was 5.0. Regarding the stabilities with respect to pH and temperature, XEG was not stable for prolonged periods, which was crucial to immobilizing it on ionic resins. XEG showed the best immobilization efficiency on CM-cellulose and DEAE-cellulose, with activities of 1.16 and 0.89 U/g of the derivative (enzyme plus support), respectively. This study describes, for the first time in the literature, the immobilization of a fungal xyloglucanase using these supports