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Id: biblio-1015723
Autor: Wang, Jiayi; Lu, Lei; Feng, Fujuan.
Título: Combined strategies for improving production of a thermo-alkali stable laccase in Pichia pastoris
Fonte: Electron. j. biotechnol;28:7-13, July. 2017. tab, graf, ilus.
Idioma: en.
Projeto: National Natural Science Foundation of China; . Fundamental Research Funds for the Central Universities.
Resumo: Background: Laccases are copper-containing enzymes which have been used as green biocatalysts for many industrial processes. Although bacterial laccases have high stabilities which facilitate their application under harsh conditions, their activities and production yields are usually very low. In this work, we attempt to use a combinatorial strategy, including site-directed mutagenesis, codon and cultivation optimization, for improving the productivity of a thermo-alkali stable bacterial laccase in Pichia pastoris. Results: A D500G mutant of Bacillus licheniformis LS04 laccase, which was constructed by site-directed mutagenesis, demonstrated 2.1-fold higher activity when expressed in P. pastoris. The D500G variant retained similar catalytic characteristics to the wild-type laccase, and could efficiently decolorize synthetic dyes at alkaline conditions. Various cultivation factors such as medium components, pH and temperature were investigated for their effects on laccase expression. After cultivation optimization, a laccase activity of 347 ± 7 U/L was finally achieved for D500G after 3 d of induction, which was about 9.3 times higher than that of wild-type enzyme. The protein yield under the optimized conditions was about 59 mg/L for D500G. Conclusions: The productivity of the thermo-alkali stable laccase from B. licheniformis expressed in P. pastoris was significantly improved through the combination of site-directed mutagenesis and optimization of the cultivation process. The mutant enzyme retains good stability under high temperature and alkaline conditions, and is a good candidate for industrial application in dye decolorization.
Descritores: Pichia/metabolismo
Lacase/biossíntese
Lacase/genética
Bacillus licheniformis/enzimologia
-Temperatura Ambiente
Leveduras
Estabilidade Enzimática
Catálise
Mutagênese
Lacase/metabolismo
Corantes/metabolismo
Concentração de Íons de Hidrogênio
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-999077
Autor: Teodoro, Thaís Silva; Oliveira, Fernanda de; Poffo, Caroline; Braga, Laís Pacenko; Arbigaus, Auriciane; Rampinelli, Jamile Rosa; Wisbeck, Elisabeth; Bonatti-Chaves, Mariane; Furlan, Sandra Aparecida.
Título: The influence of Tween 80 on laccase production by Pleurotus sajor-caju and the efficiency of crude enzyme broth in the removal of bisphenol-A / Influência do Tween 80 na produção de lacases de Pleurotus sajor-caju e eficiência do caldo enzimático bruto na remoção de bisfenol-A
Fonte: Arq. Inst. Biol;85:e1022017, 2018. tab, graf.
Idioma: en.
Projeto: CNPq; . FAP.
Resumo: Bisphenol-A is currently considered an environmental pollutant, capable of interfering in the endocrine system of organisms and causing alterations in its development and reproductive system. An alternative method to the chemical treatment of this pollutant has been the use of oxidative enzymes, especially laccases produced by fungi. In order to reduce production costs, agro-industrial waste can be used in the culture medium composition. Nonionic surfactants, which are only slightly toxic to biological membranes, can be applied, as well as Tween 80, to facilitate the excretion of these enzymes into the culture medium. The objectives of this work were: a) characterize the immersion water of banana straw used in the formulation of the culture medium; b) evaluate laccase production by Pleurotus sajor-caju in culture medium with and without addition of Tween 80, through shaken flasks; c) evaluate the efficiency of the crude enzyme broth in degrading bisphenol-A. The shaken flasks were incubated at 30°C for 12 days. The immersion water had a C:N ratio of 13.8, ash percentage of 28.6%, and pH close to neutrality. The addition of Tween 80 on the culture medium (7.5%, m/v) yielded laccase activity and productivity values equal to 3,016.47 U L-1 and 502.7 U L-1 day-1, respectively. These values were 50 and 33.5 times higher than those obtained in the culture medium without addition of Tween 80 for laccase activity and productivity, respectively. The crude enzyme broth degraded 100% of bisphenol-A after 48 hours, regardless of concentration (500, 750 and 1,000 mg L-1).(AU)

O bisfenol-A é considerado um poluente ambiental capaz de interferir no sistema endócrino dos organismos, ocasionando alterações em seu desenvolvimento e sistema de reprodução. Um método alternativo ao tratamento químico desse tipo de poluente tem sido a utilização de enzimas oxidativas, especialmente as lacases, produzidas por fungos. A fim de diminuir custos de produção, resíduos agroindustriais podem compor o meio de cultivo. Assim, surfactantes não iônicos e pouco tóxicos para as membranas biológicas, como o Tween 80, podem ser utilizados para facilitar a excreção dessas enzimas para o meio de cultivo. Os objetivos deste trabalho foram: caracterizar quimicamente o resíduo água de imersão de palha de bananeira, usado na formulação do meio de cultivo; avaliar a produção de lacase por Pleurotus sajor-caju em meio de cultivo líquido (frascos Erlenmeyer) com e sem adição de Tween 80; e avaliar a eficiência do caldo enzimático bruto em degradar bisfenol-A. Os frascos foram incubados a 30°C, por 12 dias. A água de imersão apresentou relação C:N 13,8, percentual de cinzas 28,6% e pH próximo da neutralidade. O cultivo adicionado de Tween 80 (7,5%, m/v) propiciou valores de atividade e produtividade em lacase iguais a 3.016,47 U L-1 e 502,7 U L-1 dia-1, respectivamente. Esses valores são 50 e 33,5 vezes maiores que os obtidos no cultivo sem adição de Tween 80, para atividade e produtividade em lacase, respectivamente. O caldo enzimático bruto degradou 100% do bisfenol-A após 48 horas, independentemente da concentração (500, 750 e 1.000 mg L-1).(AU)
Descritores: Polissorbatos
Tensoativos
Pleurotus
Sistema Endócrino
-Musa
Lacase
Poluentes Ambientais
Enzimas
Responsável: BR1942.1 - NID - Biblioteca - Núcleo de Informação e Documentação


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Id: biblio-988465
Autor: Flórez Sampedro, Laura; Zapata, Wildeman; Orozco, Lina P; Mejía, Amanda I; Arboleda, Carolina; Rugeles, María T.
Título: In vitro anti-HIV-1 activity of the enzymatic extract enriched with laccase produced by the fungi Ganoderma sp. and Lentinus sp / Actividad anti-VIH-1 in vitro del extracto enzimático enriquecido con lacasa producido por los hongos Ganoderma sp. y Lentinus sp
Fonte: Vitae (Medellín);23(2):109-118, 2016. Ilustraciones.
Idioma: en.
Resumo: Background: Natural compounds are a good source for the development of antiretroviral drugs with low cytotoxicity. The laccase enzyme, produced by fungi of the genera Ganoderma sp. and Lentinus sp., inhibits the reverse transcriptase (RT) of the human immunodeficiency virus 1 (HIV-1), in cell-free models in vitro. Objetives: In this study we evaluated the anti-HIV-1 activity of the enzymatic extracts (EE) enriched with laccase, produced by two native species of fungi of the same genera in an in vitro cell culture model. Methods: The inhibition of viral replication was performed using the U373-MAGI cell line infected with recombinant viruses in the presence/absence of the EE and 48 hpi, the percentage of infected cells was evaluated by flow cytometry for green fluorescent protein ­GFP­ and ELISA for p24. The inhibition of the RT was determined by quantification of early and late products of reverse transcription using quantitative PCR. Results: The EEs from Ganoderma sp. and Lentinus sp. inhibited the replication of HIV-1 between 80 and 90% and decreased the production of early and late transcripts between 55,5%-91,3% and 82,1%-93,6% respectively. The EE from Lentinus sp. had the best selectivity index (SI: 8.3). Conclusions: These results suggest the potential anti-HIV-1 activity of the EE for the exploration of an alternative therapy against HIV-1 infection.

Antecedentes: Los compuestos naturales son una buena fuente para el desarrollo de fármacos antirretrovirales con baja citotoxicidad. La enzima lacasa, producida por hongos del género Ganoderma sp. y Lentinus sp., inhibe la transcriptasa reversa (TR) del virus de la inmunodeficiencia humana tipo 1 (VIH-1), en modelos in vitro, libres de células. Objetivos: En este estudio se evaluó la actividad anti-VIH-1 del extracto enzimático (EE) enriquecido con lacasa, producida por dos especies nativas de hongos de los mismos géneros en un modelo in vitro de cultivo celular. Métodos: La inhibición de la replicación viral se realizó usando la línea celular U373-MAGI infectada con virus recombinantes en la presencia/ ausencia del EE y 48 hpi, el porcentaje de células infectadas se evaluó mediante citometría de flujo para GFP y ELISA para p24. La inhibición de la TR se determinó mediante la cuantificación de los productos tempranos y tardíos de la transcripción reversa utilizando una PCR cuantitativa. Resultados: El EE de Ganoderma sp. y Lentinus sp. inhibió la replicación del VIH-1 entre el 80 y 90% y disminuyó la producción de transcriptos tempranos y tardíos entre el 55,5% -91,3% y 82,1% -93,6%, respectivamente. El EE de Lentinus sp. mostró el mejor índice de selectividad (IS: 8.3). Conclusiones: Estos resultados sugieren el potencial anti-VIH-1 del EE para la exploración de una terapia alternativa contra la infección por el VIH-1.
Descritores: Antivirais
HIV-1
-Produtos Biológicos
Lentinula
Ganoderma
Lacase
Limites: Seres Humanos
Tipo de Publ: Artigo Clássico
Responsável: CO56.3 - Biblioteca


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Id: biblio-833153
Autor: Fabrini, Fabricia Flores; Avelino, Katielle Vieira; Marim, Renan Alberto; Cardoso, Bruna Karen; Colauto, Giani Andrea Linde; Colauto, Nelson Barros; Valle, Juliana Silveira do.
Título: Produção de lacase de Pycnoporus sanguineus em meio de cultivo à base de melaço soja / Laccase production by Pycnoporus sanguineus in culture media with soybean molasses / Producción de lacasa de Pycnoporus sanguineus en medio de cultivo con melaza de soja
Fonte: Arq. ciênc. vet. zool. UNIPAR;19(3):159-164, jul.-set. 2016. graf.
Idioma: pt.
Resumo: Lacases são polifenol oxidases que utilizam a capacidade redox de íons cobre para reduzir oxigênio a água e oxidar um substrato fenólico. A síntese e secreção de lacases de basidiomicetos dependem de vários fatores como os nutrientes presentes no meio de cultura. Visando à produção de lacase, Pycnoporus sanguineus foi cultivado em meio contendo melaço de soja como única fonte de carbono, ureia como fonte de nitrogênio suplementar em diferentes concentrações (0,6; 1,2; 2,4; 4,8 e 9,6 g/L de nitrogênio) e diferentes concentrações de CuSO4 (0, 150, 200, 250 e 300 µM). O extrato enzimático produzido nas melhores condições de cultivo foi utilizado para a descoloração dos corantes remazol azul brilhante R (antraquinona), amarelo 145, preto 5, vermelho 195 (azo) e verde malaquita (trifenilmetano). As concentrações de nitrogênio não afetaram a produção de lacase, exceto a maior concentração (9,6 g/L) que reduziu a atividade enzimática. A adição de cobre ao meio de cultivo (150 µM) aumentou a atividade de lacase em 112%. A maior atividade de lacase (~34300 U/L) promoveu a descoloração dos corantes remazol azul brilhante R (67,5%) e verde malaquita (28,3%) em 24h, sendo os corantes azo descoloridos apenas parcialmente. Concluiu-se que o melaço de soja é um resíduo agroindustrial adequado para produção de lacase de P. sanguineus com potencial para degradação de corantes.

Laccases are multicopper oxidases using the redox ability from copper ions to reduce oxygen to water, while oxidizing a phenolic substrate. Laccase synthesis and secretion in basidiomycetes depend on the conditions provided and on the nutrients present in the culture medium. Pycnoporus sanguineus was cultivated in medium containing soybean molasses as the sole carbon source, with urea as the source of supplemental nitrogen at different concentrations (0.6, 1.2, 2.4, 4.8 and 9.6 g/L nitrogen), and different CuSO4 concentrations (0, 150, 200, 250 and 300 µM). The enzymatic extract produced under the best cultivation conditions was used for the depigmentation of remazole brilliant blue R (anthraquinone), yellow 145, black 5, red 195 (azo) and malachite green (triphenylmethane). Nitrogen concentrations did not affect laccase production, except for the higher concentration (9.6 g/L) reducing enzymatic activity. The addition of copper to the culture medium (150 µM) increased laccase activity by 112%. The highest laccase activity (~34300 U/L) promoted the depigmentation of remazol brilliant blue R (67.5%) and malachite green (28.3%) dyes in 24 hours. Azo dyes were only partially discolored. Therefore, it can be considered that soybean molasses is an agro-industrial byproduct suitable for the production of P. sanguineus laccase with potential for dye degradation.

Lacasas son polifenoles oxidasas que utilizan la capacidad redox de iones de cobre para reducir el oxígeno del agua y oxidar un sustrato fenólico. La síntesis y secreción de lacasas de basidiomicetos dependen de las condiciones como los nutrientes presentes en el medio de cultura. Buscando la producción de lacasa, se cultivó Pycnoporus sanguineus en medio que contenía melaza de soja como única fuente de carbono, urea como fuente de nitrógeno suplementar a diferentes concentraciones (0,6, 1,2, 2,4, 4,8 y 9,6 g/L de nitrógeno) y diferentes concentraciones de CuSO4 (0, 150, 200, 250 y 300 µM). El extrato enzimático producido en mejores condiciones de cultivo ha sido utilizado para la decoloración de los colorantes remazol azul brillante R (antraquinona), amarillo 145, negro 5, rojo 195 (azoico) y verde malaquita (trifenilmetano). Las concentraciones de nitrógeno no afectaron la producción de lacasa, excepto la mayor concentración (9,6 g/L) que redujo la actividad enzimática. La adición de cobre al medio de cultivo (150 µM) aumentó la actividad de la lacasa en un 112%. La mayor actividad de lacasa (~34300 U/L) promovió la decoloración de los colorantes remazol azul brillante R (67,5%) y verde malaquita (28,3%) en 24h, siendo que los colorantes azoicos fueran parcialmente decolorados. Se concluye que la melaza de soja es un desecho agroindustrial adecuado para la producción de lacasa de P. sanguineus con potencial para degradación de colorantes.
Descritores: Lacase/síntese química
Melaço/provisão & distribuição
Pycnoporus/enzimologia
-Feijão de Soja/enzimologia
Responsável: BR1532.9 - CEDIC - Coordenadoria de Editoração e Divulgação Científica


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Id: lil-748256
Autor: Gomaa, Ola M.; Momtaz, Osama A..
Título: Copper induction and differential expression of laccase in Aspergillus flavus
Fonte: Braz. j. microbiol;46(1):285-292, 05/2015. tab, graf.
Idioma: en.
Resumo: Aspergillus flavus was isolated from soil and exhibited laccase activity under both constitutive and copper induced conditions. Spiking the medium with 1 mM copper sulfate resulted in an increase in the activity which reached 51.84 U/mL, a distinctive protein band was detected at 60 kDa. The extracellular enzyme was purified 81 fold using gel filtration chromatography and resulted in two different laccase fractions L1 and L2, the latter had a higher enzymatic activity which reached 79.57 U/mL and specific activity of 64.17 U/μg protein. The analysis of the spectrum of the L2 fraction showed a shoulder at 330 nm which is characteristic for T2/T3 copper centers; both copper and zinc were detected suggesting that this is an unconventional white laccase. Primers of laccase gene were designed and synthesized to recover specific gene from A. flavus. Sequence analysis indicated putative laccase (Genbank ID: JF683612) at the amino acid level suggesting a close identity to laccases from other genera containing the copper binding site. Decolorization of textile waste water under different conditions showed possible application in bioremediation within a short period of time. The effect of copper on A. flavus was concentration dependent.
Descritores: Aspergillus flavus/efeitos dos fármacos
Aspergillus flavus/enzimologia
Cobre/metabolismo
Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos
Lacase/biossíntese
Ativação Transcricional/efeitos dos fármacos
-Aspergillus flavus/genética
Aspergillus flavus/isolamento & purificação
Cromatografia em Gel
Meios de Cultura/química
DNA Fúngico/genética
Eletroforese em Gel de Poliacrilamida
Resíduos Industriais
Lacase/química
Lacase/isolamento & purificação
Dados de Sequência Molecular
Peso Molecular
Análise de Sequência de DNA
Homologia de Sequência de Aminoácidos
Microbiologia do Solo
Análise Espectral
Purificação da Água
Responsável: BR1.1 - BIREME


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Id: lil-748250
Autor: Yan, Jinping; Chen, Yuhui; Niu, Jiezhen; Chen, Daidi; Chagan, Irbis.
Título: Laccase produced by a thermotolerant strain of Trametes trogii LK13
Fonte: Braz. j. microbiol;46(1):59-65, 05/2015. tab, graf.
Idioma: en.
Projeto: Yunnan Provincial Science and Technology Department.
Resumo: Thermophilic and thermotolerant micro-organisms strains have served as the natural source of industrially relevant and thermostable enzymes. Although some strains of the Trametes genus are thermotolerant, few Trametes strains were studied at the temperature above 30 °C until now. In this paper, the laccase activity and the mycelial growth rate for Trametes trogii LK13 are superior at 37 °C. Thermostability and organic cosolvent tolerance assays of the laccase produced at 37 °C indicated that the enzyme possessed fair thermostability with 50% of its initial activity at 80 °C for 5 min, and could remain 50% enzyme activity treated with organic cosolvent at the concentration range of 25%–50% (v/v). Furthermore, the test on production of laccase and lignocellulolytic enzymes showed the crude enzymes possessed high laccase level (1000 U g−1) along with low cellulose (2 U g−1) and xylanase (140 U g−1) activity. Thus, T. trogii LK13 is a potential strain to be applied in many biotechnological processes.
Descritores: Lacase/metabolismo
Trametes/enzimologia
Trametes/crescimento & desenvolvimento
-Análise por Conglomerados
DNA Fúngico/química
DNA Fúngico/genética
DNA Espaçador Ribossômico/química
DNA Espaçador Ribossômico/genética
Estabilidade Enzimática
Lacase/química
Microscopia
Dados de Sequência Molecular
Filogenia
Análise de Sequência de DNA
Solventes
Temperatura Ambiente
Trametes/citologia
Trametes/efeitos da radiação
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


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Id: lil-734576
Autor: Kuhar, Francisco; Papinutti, Leandro.
Título: Optimization of laccase production by two strains of Ganoderma lucidum using phenolic and metallic inducers / Optimización de la producción de lacasa por dos cepas de Ganoderma lucidum utilizando inductores fenólicos y metálicos
Fonte: Rev. argent. microbiol;46(2):144-149, jun. 2014. tab, ilus, graf.
Idioma: en.
Resumo: Ganoderma lucidum (Curtis) P. Karst es un hongo causante de pudrición blanca, capaz de degradar la lignina de la madera y otros sustratos en los que crece. En este trabajo se evaluó la capacidad de dos cepas de esta especie de producir la enzima ligninolítica lacasa. Asimismo, se ensayó la inducción de esta enzima con diferentes compuestos fenólicos e iones metálicos, y se encontró que el ácido ferúlico y el cobre fueron los mejores inductores de la lacasa entre los agentes evaluados. También se encontró que los dos tipos de inductores (fenólicos y metálicos) producen distintos patrones electroforéticos de actividad lacasa. Las concentraciones óptimas de los inductores fueron establecidas mediante un diseño factorial. Se estimó la estabilidad térmica de la lacasa en un amplio rango de pH ácidos, y se comprobó que a pH más altos la enzima es más termoestable.

Ganoderma lucidum (Curtis) P. Karst is a white rot fungus that is able to degrade the lignin component in wood. The ability of two strains of this species to produce the ligninolytic enzyme laccase was assessed. After the evaluation of induction with heavy metals and phenolic compounds, it was found that among the tested substances, copper and ferulic acid are the best laccase inducers. It was also observed that the two types of inducers (phenolic and metallic) produce different electrophoretic patterns of laccase activity. Optimized concentrations of inducers were obtained through a factorial design and the thermal stability of optimized supernatants was studied at a wide range of acidic pH. We found that the enzyme is more thermostable at higher pH values.
Descritores: Lacase/biossíntese
Reishi/efeitos dos fármacos
Reishi/metabolismo
-Ácidos Cumáricos
Cobre/farmacologia
Manganês/farmacologia
Fenóis/farmacologia
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: AR1.2 - Instituto de Investigaciónes Epidemiológicas


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Id: lil-709455
Autor: Feng, Bao Zhen; Li, Peiqian.
Título: Cloning, characterization and expression of a novel laccase gene Pclac2 from Phytophthora capsici
Fonte: Braz. j. microbiol;45(1):351-358, 2014. ilus.
Idioma: en.
Projeto: Program of University of Science and Technology of Shanxi Province; . Natural Science Foundation for Young Scientists of Shanxi Province. 2013021024-6; . Yuncheng University.
Resumo: Laccases are blue copper oxidases (E.C. 1.10.3.2) that catalyze the one-electron oxidation of phenolics, aromatic amines, and other electron-rich substrates with the concomitant reduction of O2 to H2O. A novel laccase gene pclac2 and its corresponding full-length cDNA were cloned and characterized from Phytophthora capsici for the first time. The 1683 bp full-length cDNA of pclac2 encoded a mature laccase protein containing 560 amino acids preceded by a signal peptide of 23 amino acids. The deduced protein sequence of PCLAC2 showed high similarity with other known fungal laccases and contained four copper-binding conserved domains of typical laccase protein. In order to achieve a high level secretion and full activity expression of PCLAC2, expression vector pPIC9K with the Pichia pastoris expression system was used. The recombinant PCLAC2 protein was purified and showed on SDS-PAGE as a single band with an apparent molecular weight ca. 68 kDa. The high activity of purified PCLAC2, 84 U/mL, at the seventh day induced with methanol, was observed with 2,2'-azino-di-(3-ethylbenzothialozin-6-sulfonic acid) (ABTS) as substrate. The optimum pH and temperature for ABTS were 4.0 and 30 ºC, respectively . The reported data add a new piece to the knowledge about P. Capsici laccase multigene family and shed light on potential function about biotechnological and industrial applications of the individual laccase isoforms in oomycetes.
Descritores: Lacase/genética
Lacase/metabolismo
Phytophthora/enzimologia
-Clonagem Molecular
Sequência Conservada
Estabilidade Enzimática
Expressão Gênica
Concentração de Íons de Hidrogênio
Lacase/química
Lacase/isolamento & purificação
Peso Molecular
Fases de Leitura Aberta
Estrutura Terciária de Proteína
Phytophthora/genética
Pichia/genética
Sinais Direcionadores de Proteínas/genética
Proteínas Recombinantes/química
Proteínas Recombinantes/genética
Proteínas Recombinantes/isolamento & purificação
Proteínas Recombinantes/metabolismo
Homologia de Sequência de Aminoácidos
Temperatura Ambiente
Tipo de Publ: Research Support, Non-U.S. Gov't
Responsável: BR1.1 - BIREME


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Id: lil-676891
Autor: Camassola, Marli; Rosa, Letícia O. da; Calloni, Raquel; Gaio, Tamara A; Dillon, Aldo J. P.
Título: Secretion of laccase and manganese peroxidase by Pleurotus strains cultivate in solid-state using Pinus spp. sawdust
Fonte: Braz. j. microbiol;44(1):207-213, 2013. ilus, graf, tab.
Idioma: en.
Resumo: Pleurotus species secrete phenol oxidase enzymes: laccase (Lcc) and manganese peroxidase (MnP). New genotypes of these species show potential to be used in processes aiming at the degradation of phenolic compounds, polycyclic aromatic hydrocarbons and dyes. Hence, a screening of some strains of Pleurotus towards Lcc and MnP production was performed in this work. Ten strains were grown through solid-state fermentation on a medium based on Pinus spp. sawdust, wheat bran and calcium carbonate. High Lcc and MnP activities were found with these strains. Highest Lcc activity, 741 ± 245 U gdm-1 of solid state-cultivation medium, was detected on strain IB11 after 32 days, while the highest MnP activity occurred with strains IB05, IB09, and IB11 (5,333 ± 357; 4,701 ± 652; 5,999 ± 1,078 U gdm-1, respectively). The results obtained here highlight the importance of further experiments with lignocellulolytic enzymes present in different strains of Pleurotus species. Such results also indicate the possibility of selecting more valuable strains for future biotechnological applications, in soil bioremediation and biological biomass pre-treatment in biofuels production, for instance, as well as obtaining value-added products from mushrooms, like phenol oxidase enzymes.
Descritores: Compostos Fenólicos/análise
Técnicas In Vitro
Lacase/análise
Lacase/isolamento & purificação
Manganês/análise
Manganês/isolamento & purificação
Oxirredutases/análise
Peroxidase/análise
Peroxidase/isolamento & purificação
Pinus/genética
Pleurotus/isolamento & purificação
-Biodegradação Ambiental
Ativação Enzimática
Genótipo
Métodos
Responsável: BR32.1 - Serviço de Biblioteca e Informação Biomédica


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Id: lil-671882
Autor: Revollo Escudero, Enrique Luis; Serna Daza, Oriana Danuta; Hernández Torres, Jorge.
Título: Caracterización de actinobacterias raras, degradadoras de lignocelulosa: demostración de actividad lacasa en dos aislados de Tsukamurella sp y Cellulosimicrobium sp / Characterization of lignocellulose-degrading rare actinobacteria: demostration of laccase activity in two isolates of Tsukamurella sp and Cellulosimicrobium sp
Fonte: Rev. colomb. biotecnol;14(2):70-80, dic. 2012. ilus, tab.
Idioma: es.
Resumo: Las características fisicoquímicas de la lignina y su compactación con la celulosa han dificultado la explotación biotecnológica de enormes cantidades de biomasa vegetal. Las lacasas constituyen una subfamilia de oxidasas multicobre que intervienen en la despolimerización de la lignina. Si bien han sido ampliamente caracterizadas en los hongos, los estudios de la diversidad y las funcionalidades de las lacasas en los procariotas se han centrado especialmente en isoformas enzimáticas de Streptomyces sp. En este trabajo se aislaron 20 cepas de actinobacterias del suelo. La actividad lacasa de 17 de ellas fue evidenciada en ensayos cualitativos con guayacol y dos cepas seleccionadas fueron caracterizadas en detalle. Las pruebas morfológicas y el análisis de las secuencias del gen 16S rRNA apuntan a que estos dos aislados pertenecen a los géneros Tsukamurella y Cellulosimicrobium. En cultivo sumergido con agitación, AC01 (Tsukamurella sp.) expresó una máxima actividad de oxidación de ABTS (2,2'-azino-bis-(3-etilbenzotiazolin-6-sulfonato) de 108 U/L. Por otra parte, AC18 (Cellulosimicrobium sp.) que había exhibido una actividad oxidativa de guayacol superior a las 16 cepas restantes y demostró ser resistente a niveles tóxicos de cobre, logró un valor máximo de oxidación del ABTS de 0,56 U/L. Estos resultados sugieren que en el aislado AC18 operaría un fenómeno de especificidad de sustrato o de inductor, regulador de la expresión y de la actividad lacasa cuantificable. La caracterización genómica y funcional de las lacasas de nuevas actinobacterias lignocelulósicas ampliará la gama de centros redox con aplicaciones biotecnológicas específicas, además de facilitar el establecimiento de sus relaciones evolutivas con las eucariotas.

The physicochemical characteristics of lignin and its compaction with cellulose have restricted the biotechnological exploitation of enormous amounts of plant biomass. Laccases are a subfamily of multicopper oxidases involved in lignin depolymerization. Although they have been extensively characterized in fungi, studies of the diversity and functions of laccases in prokaryotes are mainly on enzyme isoforms of Streptomyces sp. In this work we isolated 20 strains of soil actinomycetes. The laccase activity of 17 of them was evidenced in qualitative assays with guaiacol, and two selected strains were characterized in detail. The morphological evidence and the analysis of the 16S rRNA gene sequences suggest that these two isolates belong to the genera Tsukamurella and Cellulosimicrobium. In submerged cultures with shaking, AC01 (Tsukamurella sp.) exhibited a maximal oxidation activity of ABTS (2,2 '-azino-bis-(3-ethylbenzthiazoline-6-sulfonate) of 108 U/L. On the other hand, AC18 (Cellulosimicrobium sp.) that exhibited a higher oxidative activity of guaiacol than the other 16 isolated strains and showed resistance to toxic levels of copper, reached a maximum ABTS oxidation rate of 0.56 U/L. These results suggest that in AC18 operates a mechanism of substrate or inducer specificity, regulating the measurable laccase activity and laccase gene expression. Genomic and functional characterization of laccases of new ligninolytic actinomycetes may help to extend the range of redox centers with specific biotechnological applications, as well as establishing their evolutionary relationships with eukaryotes.
Descritores: Actinobacteria
Enzimas
Lacase
Lignina
-Biomassa
Celulose
Fungos
Responsável: CO326 - Departamento de Biología



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