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Isolation and cloning of the gene that encodes the lipase of the fungus endomelanconiopsis endophytica
No full textScientific discoveries and technological advances in the field of molecular biology of
proteins, especially in the late 19th and early 20th century, contributed to the
employment of biocatalysts by industries. This way, enzymes started to occupy an
important role in economically profitable activities. Lipases are among the hydrolytic
enzymes of great interest, because they are versatile biocatalysts, capable to
catalyze various reactions, both in aqueous and organic medium with water content
restricted. Although lipase are widely distributed, it can be said that these enzymes
are the most studied and exploited for its expression and production by fungi. In
microorganisms, lipases are able to show phospholipid activity, being used as a
defense mechanism, since when secreted, they provide competition with the
microflora; facilitate the digestion of lipids and fatty acids released assist in tissue
adhesion, cell-cell and cell-host. In this work, we isolated the lipase gene of the
fungus Endomelanconiopsis endophytica through several molecular biology tools,
such as the extraction of mRNA and synthesis of double stranded cDNA.As descobertas científicas e os avanços tecnológicos no campo da biologia
molecular de proteínas, principalmente no final do século XIX e início do século XX,
contribuíram para o emprego de biocatalizadores pelas indústrias. Assim as enzimas
passaram a ocupar um papel importante em atividades economicamente lucrativas.
As lipases estão entre as enzimas hidrolíticas de grande interesse, são
biocatalisadores versáteis, capazes de catalisar diferentes reações, tanto em meio
aquoso como em meio orgânico com teor de água restrito. Apesar das lipases
estarem amplamente distribuídas, pode-se dizer que estas enzimas são mais
estudadas e exploradas quanto a sua expressão e produção por fungos. Nos
microrganismos, as lipases podem apresentar atividade fosfolipídica, sendo
utilizadas como mecanismo de defesa, visto que quando secretadas, proporcionam
competição com a microflora; facilitam a digestão dos lipídeos e os ácidos graxos
livres liberados auxiliam na adesão tecidual célula-célula e célula-hospedeiro. Neste
trabalho isolamos o gene da lipase do fungo Endomelanconiopsis endophytica
através de diversas ferramentas de biologia molecular, como a extração do mRNA e
síntese de cDNA dupla fita
Prospecção, caracterização e purificação de lipase microbiana
No full textLipases are enzymes which catalyze the synthesis and hydrolysis of glycerides in triacylglycerols and fatty acids. Its use as a biological catalyst has taken various applications in the pharmaceutical and food industries. Your source may be either animal, plant and microbial. With great emphasis on the latter due to the advantages as a means of obtaining, handling and great diversity, which makes filamentous fungi an interesting source of lipases. The search for new sources provides several jobs with specific objectives. Thus the aim of this study was to evaluate and select among two collections of filamentous fungi, potential producers of lipases. For this study, 316 strains were actually tested for lipolytic activity in liquid culture medium inducing lipase (olive oil). Of this total, 298 (94%) were positive and their lipase activity observed from the hydrolysis reaction with the substrate p-NPP with reading in the spectrophotometer at 410 nm. Only isolates exhibiting activity above 7000 U / ml were selected. Thus, only six isolates showed activities considered good and underwent further testing with enzyme activity in palm oil. The most promising strain was identified through molecular techniques as Endomelanconiopsis endophytica, producing an activity of 7895 U/mL for the olive oil and 10,727 U/mL for palm oil. The crude
extract was then purified by ion exchange chromatography, resulting in three enzymes active form (two of 60 and one of 46 kDa) quantified by SDS-PAGE. And their identity verified by mass spectral and N-terminal sequencing by Edmann degradation. Two of them were presented blocked and the 46 kDa its sequence was obtained. Thus the study sought to contribute to the discovery of new lipases with biotechnological potential, contributing to a future database protein.
Keywords: lipases, filamentous fungi, submerged fermentation, purificationAs lipases são enzimas que catalisam a síntese e a hidrólise de triacilglicerídeos em glicerídeos e ácidos graxos. Sua utilização como catalisador biológico tem tomado vários aplicações na indústria farmacêutica e alimentar. Sua fonte pode ser tanto de origem animal, vegetal e microbiológica. Com grande destaque para a última devido às vantagens como forma de obtenção, manuseio e grande diversidade, o que torna os fungos filamentosos uma ampla fonte de lipases. A busca por novas fontes proporciona vários trabalhos com objetivos específicos. Assim o objetivo do trabalho foi selecionar e avaliar dentre duas coleções de fungos filamentosos, possíveis produtores de lipases. Para este estudo, 316 isolados foram efetivamente testados quanto à atividade lipolítica em meio de cultura líquido indutor de lipase (óleo de oliva). Desse total, 298 (94%) apresentaram-se lipase positivos e suas atividade verificada a partir da reação de hidrólise com o substrato p-NPP com leitura no espectrofotômetro a 410 nm. Como forma de seleção, apenas os isolados que apresentaram atividade acima de 7000 U/ml foram selecionados. Com isso, somente seis isolados apresentaram atividades consideradas boas e foram submetidas a novos ensaios com a atividade enzimática em
óleo de dendê. A cepa mais promissora foi identificada através de técnicas moleculares como Endomelanconiopsis endophytica, produzindo uma atividade de 7895 U/mL para o óleo de oliva e 10727 U/mL para o óleo de dendê. O extrato bruto foi então purificado através da cromatografia de troca iônica, resultando em três enzimas de forma ativa (duas de 60 e uma de 46 kDa) quantificada em SDS-PAGE. E suas identidades verificadas através do espectro de massa e do sequenciamento do N-terminal, pela degradação de Edmann. Duas delas apresentaram-se bloqueadas e a de 46 kDa foi obtida sua sequência. Assim o estudo procurou contribuir para a descoberta de novas lipases com o potencial biotecnológico, contribuindo para um futuro banco de dados protéico.
Palavras-chave: lipases extracelulares, fungos filamentosos, fermentação submersa; purificaçã
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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