92 research outputs found
Production and Partial Characterization of Cellulases from Trichoderma sp. IS-05 Isolated from Sandy Coastal Plains of Northeast Brazil
This study evaluated the production of cellulolytic enzymes by Trichoderma sp. IS-05 strain, isolated from sand dunes, according to its ability to grow on cellulose as carbon source. Wheat bran was tested as the carbon source and peptone tested as the nitrogen source. Different concentrations of carbon and nitrogen were tested using a factorial design to identify optimal cellulase activity production. The results showed that media containing wheat bran 4.0% (w/v) and peptone 0.25% (w/v) lead to the highest production, 564.0 U L−1 of cellulase, obtained after 2 days of fermentation. The pH and temperature profile showed optimal activity at pH 3.0 and 60°C. As for thermostability, the cellulase was most tolerant at 60°C, retaining more than 59.6% of maximal activity even after 4 hours of incubation. The combination of acid pH, high temperature tolerance, and production of cellulase from agro-industrial residues by Trichoderma sp. IS-05 offers possibilities condition for the biomass hydrolysis process to produce bioethanol
A thermotolerant xylan-degrading enzyme is produced by Streptomyces malaysiensis AMT-3 using by-products from the food industry
ABSTRACT: This study evaluated the production of endoxylanases by Streptomyces malaysiensis AMT-3 in submerged fermentation using by-products of the food industry at 28ºC. In shake-flasks experiments, the highest endoxylanase activity of 45.8 U.mL-1 was observed within 6 days in a medium containing (w/v) 2.5% wheat bran and 1.2% corn steep liquor. The same culture conditions were used to evaluate the enzyme production in a 2 L stirred tank reactor under different agitation (300, 450 and 600 rev.min-1) and aeration (30 and 60 L.h-1) conditions. The use of 450 rev.min-1 coupled to an aeration of 90 L.h-1 resulted on 81.3 U.mL-1 endoxylanase activity within 5 days. The effect of temperature and pH on endoxylanase activity and stability showed the highest activity at 60 ºC and pH 6.0. Zymography showed the presence of three xylanolytic bands with molecular masses of 690, 180 and 142 kDa. The results showed that the thermotolerant actinobacterial endoxylanase can be produced in high titers using by-product of the food industry.info:eu-repo/semantics/publishedVersio
Production of thermophilic and acidophilic endoglucanases by mutant Trichoderma atroviride 102C1 using agro-industrial by-products
Many traditional mutagenic strategies have been used to improve cellulase production by microorganisms, especially fungi species. Trichoderma species are among cellulolytic fungi, those that have been most extensively studied, due to their efficient production of these enzymes. In the present study, N-methyl-N´-nitro-N nitrosoguanidine (NTG) was used as mutagenic agent to obtain cellulolytic mutant from wild strain T. atroviride 676. After mutagenic procedures, two strains (102C1 and 104C2) were selected as promising cellulase-producing mutant. The effect of the carbon (sugarcane bagasse: SCB) and nitrogen (corn steep liquor: CSL) sources on endoglucanase production by the mutants 102C1 and 104C2 was studied using submerged cultivations at 28°C. Different concentrations of SCB and CSL were used and nine different media were generated. Mutant 102C1 showed the best results when using 2.5% SCB and 0.7% CSL. A central composite rotational design (CCRD) was performed to estimate optimal conditions of pH and temperature for endoglucanase activity of strain 102C1, which were pH 3.6 and temperature 66°C. The characterization of this acidophilic and thermophilic endoglucanase activity produced by the mutant strain 102C1 allows its use in biotechnological applications, particularly in the hydrolysis of agro industrial residues, such as SCB, for bioethanol production.Keywords: Trichoderma atroviride, CMCase, nitrosoguanidine, sugarcane bagasse, corn steep liquo
Convergência ao padrão IFRS e suavização de resultados em empresas de energia elétrica
The objective of this research is to analyze if there has been an increase in earnings management level (GR) using the income smoothing method in the electricity sector companies listed on the B3 with the adoption of the accounting standards of the IASB. The proposal is timely, since, due to the greater flexibility of the rules, there is the possibility of a greater GR. On the other hand, it is a heavily regulated industry, prompting, in turn, the possibility of this factor inhibiting such practices. Were analyzed the financial statements from 2003 to 2007 as the preconvergence period, and 2010 to 2014 as the post-convergence period. As GR proxy, the variance of waste equation proposed by Chen et al. (2010) and Barth et al. (2008) was considered, with adaptations, where a smaller variability in net profit is seen as practice for greater smoothing results and higher GR. The research findings show a reduction in the level of income smoothing after the adoption of IFRS (International Financial Reporting Standards). In fact, the findings indicate that the adoption of international standards for companies in that sector can improve the quality of accounting information and therefore reduce the earnings management levels, mainly due to the demand for greater disclosure and quality of financial reporting, corroborating with the results of the researches of Barth et al. (2008), Iatridis (2010) and Chen et al. (2010). Keywords: income smothing, electricity sector, international standards.O objetivo da pesquisa é o de analisar se houve um aumento no nível de gerenciamento de resultados (GR) pelo método income smoothing nas companhias do subsetor de energia elétrica listadas na B3 com a adoção das normas contábeis do IASB. A referida proposta é oportuna, uma vez que, em razão da maior flexibilidade das normas, há possibilidade de maior GR. Por outro lado, trata-se de subsetor fortemente regulamentado, instigando, por seu turno, se esse fator poderia inibir tais práticas. Foram analisadas as demonstrações financeiras de 2003 a 2007 como pré-convergência e de 2010 a 2014 como pós-convergência. Como proxy de GR, foi considerada a variância dos resíduos da equação proposta por Chen et al. (2010) e Barth et al. (2008), com adaptações, em que uma menor variabilidade no lucro líquido é vista como prática de maior suavização de resultados e maior GR. Os achados da pesquisa evidenciam uma redução no nível de income smoothing a partir da adoção das IFRS (International Financial Reporting Standards). Com efeito, as conclusões permitem inferir que a adoção dessas normas nas empresas do referido subsetor pode melhorar a qualidade da informação contábil e, por conseguinte, reduzir os níveis de gerenciamento de resultados, principalmente pela exigência de maior evidenciação e qualidade dos relatórios contábeis, o que corrobora os resultados das pesquisas de Barth et al. (2008), Iatridis (2010) e Chen et al. (2010).Palavras-chave: suavização de resultados, setor elétrico, normas internacionais
ANÁLISE DAS UNIDADES DE CONSERVAÇÃO NO MUNICÍPIO DE APARECIDA DE GOIÂNIA: RELATO DE UMA EXPERIÊNCIA DE EXTENSÃO UNIVERSITÁRIA: Analysis of conservation units in the municipality of aparecida of goiânia: report of an experience of university extension
Esse artigo tem como objetivo revelar uma experiência de extensão universi- tária que teve como foco analisar a importância da vegetação em áreas urbanas e urbanizadas. Para alcançar o objetivo aplicou-se a metodologia Hands-on a partir das atividades de extensão do projeto Aprender Fazendo para estudantes do ensino médio de escolas públicas e estudantes do ensino superior da Universidade Federal de Goiás, Aparecida de Goiânia. Os principais resultados revelaram práticas multi- disciplinares de ensino através de atividades em campo. Desse modo, na perspectiva das geociências, realizou-se análises integradas da paisagem nas Unidades de Con- servação e da relação entre a geologia local, preservação dos solos com a presença de vegetação nativa e das nascentes. Na perspectiva da cartografia, os estudantes do ensino superior elaboraram mapeamentos temáticos que foram analisados por estu- dantes do ensino médio
Molecular epidemiological investigation of Mayaro virus in febrile patients from Goiania City, 2017-2018.
Mayaro virus (MAYV) has historically been associated with sylvatic transmission; however, urban outbreaks have been reported in Brazil, including cases of co-detection with dengue virus (DENV). Therefore, we performed a molecular survey to investigate MAYV circulation and cocirculation with DENV within Goiania, a major city in Central-West Brazil. Among 375 subjects with arbovirus-like symptoms, 259 were positive for DENV and 26 for MAYV. Of these, 17 were coinfected with DENV-2, suggesting co-transmission of the viruses. The most common complaints at the time of inclusion were myalgia, headache, fever, arthralgia, retro-orbital pain, and skin rash. No specific symptoms were associated with MAYV when either detected alone or co-detected with DENV, compared to that when DENV was detected alone. Most MAYV-infected subjects were women with no recent travel history to rural/sylvatic areas. Phylogenetic reconstruction indicated that the MAYV identified in this study is closely related with a lineage observed in Peru, belonging to genotype D. Our results corroborate the growing circulation of MAYV in urban environments in Brazil and reinforce the need to implement laboratory diagnosis in the Unified Health System, considering that the clinical manifestations of Mayaro fever are similar to those of other arboviruses, particularly dengue. Furthermore, most cases occurred in association with DENV-2. Further phylogenetic studies are needed to evaluate MAYV, which has not been widely examined
Transtorno bipolar em crianças: análise de relato de caso 2018-2023
O transtorno bipolar em crianças é uma realidade clínica que demanda atenção especializada. A compreensão dos sintomas, fatores de risco, prevalência e desafios diagnósticos é fundamental para proporcionar intervenções precoces e adequadas, visando melhorar a qualidade de vida desses jovens e reduzir o impacto a longo prazo dessa condição psiquiátrica. Trata-se de um estudo cujo objetivo foi objetivo revisar relatos de caso publicados entre 2018 e 2023 sobre transtorno bipolar em crianças, identificando o estado da arte desses estudos. Para isso, se realizou uma revisão sistemática de literatura utilizando as bases de dados Medical Literature Analysis and Retrieval System Online (MEDLINE), Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e Scientific Electronic Library Online (SCIELO). Com a análise e interpretação qualitativa dos resultados, a principal conclusão deste estudo é que o transtorno bipolar na infância é uma condição complexa, manifestando-se com comportamentos consistentes com o Transtorno de Conduta e sendo influenciado por fatores ambientais, familiares e genéticos. O tratamento eficaz requer uma abordagem multidisciplinar, integrando intervenções farmacológicas e não farmacológicas, personalizadas conforme as necessidades individuais. A supervisão familiar é crucial para a adesão ao tratamento, mas reconhece-se a necessidade contínua de pesquisa para aprimorar as estratégias terapêuticas diante da diversidade de casos
Estimating the global conservation status of more than 15,000 Amazonian tree species
Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century
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