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Id: biblio-951810
Autor: Rungrattanakasin, Budsayachat; Premjet, Siripong; Thanonkeo, Sudarat; Klanrit, Preekamol; Thanonkeo, Pornthap.
Título: Cloning and expression of an endoglucanase gene from the thermotolerant fungus Aspergillus fumigatus DBiNU-1 in Kluyveromyces lactis
Fonte: Braz. j. microbiol;49(3):647-655, July-Sept. 2018. graf.
Idioma: en.
Resumo: Abstract An intronless endoglucanase from thermotolerant Aspergillus fumigatus DBINU-1 was cloned, characterized and expressed in the yeast Kluyveromyces lactis. The full-length open reading frame of the endoglucanase gene from A. fumigatus DBiNU-1, designated Cel7, was 1383 nucleotides in length and encoded a protein of 460 amino acid residues. The predicted molecular weight and the isoelectric point of the A. fumigatus Cel7 gene product were 48.19 kDa and 5.03, respectively. A catalytic domain in the N-terminal region and a fungal type cellulose-binding domain/module in the C-terminal region were detected in the predicted polypeptide sequences. Furthermore, a signal peptide with 20 amino acid residues at the N-terminus was also detected in the deduced amino acid sequences of the endoglucanase from A. fumigatus DBiNU-1. The endoglucanase from A. fumigatus DBiNU-1 was successfully expressed in K. lactis, and the purified recombinant enzyme exhibited its maximum activity at pH 5.0 and 60 °C. The enzyme was very stable in a pH range from 4.0 to 8.0 and a temperature range from 30 to 60 °C. These features make it suitable for application in the paper, biofuel, and other chemical production industries that use cellulosic materials.
Descritores: Aspergillus fumigatus/enzimologia
Proteínas Fúngicas/genética
Proteínas Fúngicas/química
Expressão Gênica
Celulase/genética
Celulase/química
Clonagem Molecular
-Aspergillus fumigatus/genética
Especificidade por Substrato
Estabilidade Enzimática
Kluyveromyces/genética
Kluyveromyces/metabolismo
Proteínas Recombinantes/genética
Proteínas Recombinantes/metabolismo
Proteínas Recombinantes/química
Proteínas Fúngicas/metabolismo
Celulase/metabolismo
Temperatura Alta
Concentração de Íons de Hidrogênio
Responsável: BR1.1 - BIREME


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Id: biblio-828205
Autor: Aliabadi, Nasrin; Aminzadeh, Saeed; Karkhane, Ali Asghar; Haghbeen, Kamahldin.
Título: Thermostable chitinase from Cohnella sp. A01: isolation and product optimization
Fonte: Braz. j. microbiol;47(4):931-940, Oct.-Dec. 2016. tab, graf.
Idioma: en.
Projeto: International Foundation for Science; . Committee on Scientific and Technological Cooperation; . National Institute of Genetic Engineering and Biotechnology.
Resumo: Abstract Twelve bacterial strains isolated from shrimp farming ponds were screened for their growth activity on chitin as the sole carbon source. The highly chitinolytic bacterial strain was detected by qualitative cup plate assay and tentatively identified to be Cohnella sp. A01 based on 16S rDNA sequencing and by matching the key morphological, physiological, and biochemical characteristics. The cultivation of Cohnella sp. A01 in the suitable liquid medium resulted in the production of high levels of enzyme. The colloidal chitin, peptone, and K2HPO4 represented the best carbon, nitrogen, and phosphorus sources, respectively. Enzyme production by Cohnella sp. A01 was optimized by the Taguchi method. Our results demonstrated that inoculation amount and temperature of incubation were the most significant factors influencing chitinase production. From the tested values, the best pH/temperature was obtained at pH 5 and 70 °C, with Km and V max values of chitinase to be 5.6 mg/mL and 0.87 µmol/min, respectively. Ag+, Co2+, iodoacetamide, and iodoacetic acid inhibited the enzyme activity, whereas Mn2+, Cu2+, Tweens (20 and 80), Triton X-100, and EDTA increased the same. In addition, the study of the morphological alteration of chitin treated by enzyme by SEM revealed cracks and pores on the chitin surface, indicating a potential application of this enzyme in several industries.
Descritores: Bacillus/metabolismo
Quitinases/metabolismo
-Fósforo/metabolismo
Temperatura
Bacillus/isolamento & purificação
Bacillus/genética
Bacillus/ultraestrutura
Estabilidade Enzimática/efeitos dos fármacos
Carbono/metabolismo
RNA Ribossômico 16S/genética
Cinética
Quitinases/química
Análise de Sequência de DNA
Ativação Enzimática
Concentração de Íons de Hidrogênio
Íons
Metais
Nitrogênio/metabolismo
Responsável: BR1.1 - BIREME


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Carvalho, Patricia de Oliveira
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Id: biblio-828204
Autor: Araújo, Maria Elisa Melo Branco de; Campos, Paula Renata Bueno; Alberto, Thiago Grando; Contesini, Fabiano Jares; Carvalho, Patrícia de Oliveira.
Título: Synthesis of structured triacylglycerols enriched in n-3 fatty acids by immobilized microbial lipase
Fonte: Braz. j. microbiol;47(4):1006-1013, Oct.-Dec. 2016. tab, graf.
Idioma: en.
Resumo: Abstract The search for new biocatalysts has aroused great interest due to the variety of micro-organisms and their role as enzyme producers. Native lipases from Aspergillus niger and Rhizopus javanicus were used to enrich the n-3 long-chain polyunsaturated fatty acids content in the triacylglycerols of soybean oil by acidolysis with free fatty acids from sardine oil in solvent-free media. For the immobilization process, the best lipase/support ratios were 1:3 (w/w) for Aspergillus niger lipase and 1:5 (w/w) for Rhizopus javanicus lipase using Amberlite MB-1. Both lipases maintained constant activity for 6 months at 4 °C. Reaction time, sardine-free fatty acids:soybean oil mole ratio and initial water content of the lipase were investigated to determine their effects on n-3 long-chain polyunsaturated fatty acids incorporation into soybean oil. Structured triacylglycerols with 11.7 and 7.2% of eicosapentaenoic acid + docosahexaenoic acid were obtained using Aspergillus niger lipase and Rhizopus javanicus lipase, decreasing the n-6/n-3 fatty acids ratio of soybean oil (11:1 to 3.5:1 and 4.7:1, respectively). The best reaction conditions were: initial water content of lipase of 0.86% (w/w), sardine-free faty acids:soybean oil mole ratio of 3:1 and reaction time of 36 h, at 40 °C. The significant factors for the acidolysis reaction were the sardine-free fatty acids:soybean oil mole ratio and reaction time. The characterization of structured triacylglycerols was obtained using easy ambient sonic-spray ionization mass spectrometry. The enzymatic reaction led to the formation of many structured triacylglycerols containing eicosapentaenoic acid, docosahexaenoic acid or both polyunsaturated fatty acids.
Descritores: Triglicerídeos
Hidrolases de Éster Carboxílico/química
Ácidos Graxos Ômega-3
Enzimas Imobilizadas
-Triglicerídeos/química
Estabilidade Enzimática
Ácidos Graxos Ômega-3/síntese química
Cromatografia Gasosa
Espectrometria de Massas por Ionização por Electrospray
Responsável: BR1.1 - BIREME


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Id: lil-788974
Autor: Gururaj, P; Ramalingam, Subramanian; Devi, Ganesan Nandhini; Gautam, Pennathur.
Título: Process optimization for production and purification of a thermostable, organic solvent tolerant lipase from Acinetobacter sp. AU07
Fonte: Braz. j. microbiol;47(3):647-657, July-Sept. 2016. tab, graf.
Idioma: en.
Projeto: Department of Biotechnology, Government of India.
Resumo: ABSTRACT The purpose of this study was to isolate, purify and optimize the production conditions of an organic solvent tolerant and thermostable lipase from Acinetobacter sp. AU07 isolated from distillery waste. The lipase production was optimized by response surface methodology, and a maximum production of 14.5 U/mL was observed at 30 ºC and pH 7, using a 0.5% (v/v) inoculum, 2% (v/v) castor oil (inducer), and agitation 150 rpm. The optimized conditions from the shake flask experiments were validated in a 3 L lab scale bioreactor, and the lipase production increased to 48 U/mL. The enzyme was purified by ammonium sulfate precipitation and ion exchange chromatography and the overall yield was 36%. SDS-PAGE indicated a molecular weight of 45 kDa for the purified protein, and Matrix assisted laser desorption/ionization time of flight analysis of the purified lipase showed sequence similarity with GDSL family of lipases. The optimum temperature and pH for activity of the enzyme was found to be 50 ºC and 8.0, respectively. The lipase was completely inhibited by phenylmethylsulfonyl fluoride but minimal inhibition was observed when incubated with ethylenediaminetetraacetic acid and dithiothreitol. The enzyme was stable in the presence of non-polar hydrophobic solvents. Detergents like SDS inhibited enzyme activity; however, there was minimal loss of enzyme activity when incubated with hydrogen peroxide, Tween 80 and Triton X-100. The kinetic constants (Km and Vmax) revealed that the hydrolytic activity of the lipase was specific to moderate chain fatty acid esters. The Vmax, Km and Vmax/Km ratio of the enzyme were 16.98 U/mg, 0.51 mM, and 33.29, respectively when 4-nitrophenyl palmitate was used as a substrate.
Descritores: Compostos Orgânicos
Solventes
Proteínas de Bactérias/isolamento & purificação
Proteínas de Bactérias/biossíntese
Acinetobacter/enzimologia
Lipase/isolamento & purificação
Lipase/biossíntese
-Compostos Orgânicos/química
Solventes/química
Especificidade por Substrato
Temperatura
Proteínas de Bactérias/química
Estabilidade Enzimática
Cinética
Cromatografia por Troca Iônica
Ativação Enzimática
Espaço Extracelular/enzimologia
Concentração de Íons de Hidrogênio
Íons
Lipase/química
Lipólise
Metais
Peso Molecular
Responsável: BR1.1 - BIREME


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Id: lil-780826
Autor: Fonseca, María Isabel; Tejerina, Marcos Raúl; Sawostjanik-Afanasiuk, Silvana Soledad; Giorgio, Ernesto Martin; Barchuk, Mónica Lucrecia; Zapata, Pedro Darío; Villalba, Laura Lidia.
Título: Preliminary studies of new strains of Trametes sp. from Argentina for laccase production ability
Fonte: Braz. j. microbiol;47(2):287-297, Apr.-June 2016. tab, graf.
Idioma: en.
Resumo: Abstract Oxidative enzymes secreted by white rot fungi can be applied in several technological processes within the paper industry, biofuel production and bioremediation. The discovery of native strains from the biodiverse Misiones (Argentina) forest can provide useful enzymes for biotechnological purposes. In this work, we evaluated the laccase and manganese peroxidase secretion abilities of four newly discovered strains of Trametes sp. that are native to Misiones. In addition, the copper response and optimal pH and temperature for laccase activity in culture supernatants were determined.The selected strains produced variable amounts of laccase and MnP; when Cu2+ was added, both enzymes were significantly increased. Zymograms showed that two isoenzymes were increased in all strains in the presence of Cu2+. Strain B showed the greatest response to Cu2+ addition, whereas strain A was more stable at the optimal temperature and pH. Strain A showed interesting potential for future biotechnological approaches due to the superior thermo-stability of its secreted enzymes.
Descritores: Proteínas Fúngicas/metabolismo
Lacase/metabolismo
Trametes/enzimologia
-Argentina
Temperatura
Estabilidade Enzimática
Proteínas Fúngicas/genética
Proteínas Fúngicas/química
Lacase/genética
Lacase/química
Trametes/isolamento & purificação
Trametes/genética
Responsável: BR1.1 - BIREME


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ASTOLFI-FILHO, SPARTACO
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Id: biblio-1022139
Autor: Santa-Rosa, Pamella S; Souza, Anita L; Roque, Rosemary A; Andrade, Edmar V; Astolfi-Filho, Spartaco; Mota, Adolfo J; Nunes-Silva, Carlos G.
Título: Production of thermostable ß-glucosidase and CMCase by Penicillium sp: LMI01 isolated from the Amazon region
Fonte: Electron. j. biotechnol;31:84-92, Jan. 2018. graf, tab, ilus.
Idioma: en.
Projeto: Fundação de Amparo a Pesquisa do Amazonas, FAPEAM - PAPPE Integração; . Coordenação de Aperfeiçoamento de Pessoal Nível Superior, CAPES; . Conselho Nacional de Desenvolvimento Científico e Tecnológico, CNPq.
Resumo: Background: Cellulolytic enzymes of microbial origin have great industrial importance because of their wide application in various industrial sectors. Fungi are considered the most efficient producers of these enzymes. Bioprospecting survey to identify fungal sources of biomass-hydrolyzing enzymes from a high-diversity environment is an important approach to discover interesting strains for bioprocess uses. In this study, we evaluated the production of endoglucanase (CMCase) and ß-glucosidase, enzymes from the lignocellulolytic complex, produced by a native fungus. Penicillium sp. LMI01 was isolated from decaying plant material in the Amazon region, and its performance was compared with that of the standard isolate Trichoderma reesei QM9414 under submerged fermentation conditions. Results: The effectiveness of LMI01 was similar to that of QM9414 in volumetric enzyme activity (U/mL); however, the specific enzyme activity (U/mg) of the former was higher, corresponding to 24.170 U/mg of CMCase and 1.345 U/mg of ß-glucosidase. The enzymes produced by LMI01 had the following physicochemical properties: CMCase activity was optimal at pH 4.2 and the ß-glucosidase activity was optimal at pH 6.0. Both CMCase and ß-glucosidase had an optimum temperature at 60°C and were thermostable between 50 and 60°C. The electrophoretic profile of the proteins secreted by LMI01 indicated that this isolate produced at least two enzymes with CMCase activity, with approximate molecular masses of 50 and 35 kDa, and ß-glucosidases with molecular masses between 70 and 100 kDa. Conclusions: The effectiveness and characteristics of these enzymes indicate that LMI01 can be an alternative for the hydrolysis of lignocellulosic materials and should be tested in commercial formulations.
Descritores: Penicillium/enzimologia
Celulase/biossíntese
beta-Glucosidase/biossíntese
-Oligossacarídeos
Temperatura
Trichoderma/enzimologia
Estabilidade Enzimática
Celulase/metabolismo
beta-Glucosidase/metabolismo
Ecossistema Amazônico
Biocatálise
Fermentação
Concentração de Íons de Hidrogênio
Hidrólise
Lignina/metabolismo
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-1022044
Autor: Revin, Victor; Atykyan, Nelli; Lyovina, Ekaterina; Dragunova, Yuliya; Ushkina, Victoriya.
Título: Effect of ultraviolet radiation on physiological and biochemical properties of yeast Saccharomyces cerevisiae during fermentation of ultradispersed starch raw material
Fonte: Electron. j. biotechnol;31:61-66, Jan. 2018. graf, ilus, tab.
Idioma: en.
Projeto: Ministry of Education and Science of the Russian Federation.
Resumo: Background: Study of correlation between pretreatment of yeast with ultraviolet radiation and efficiency of further fermentation of wort made of ultrafine grain particles to ethanol. Results: We investigated three races of industrial yeast Saccharomyces cerevisiae (native and irradiated by ultraviolet). Physiological properties during fermentation of starchy wort were tested in all variants. It was shown that activation of the yeast by ultraviolet radiation allows to further increase the ethanol yield by 25% on average compared with the native yeast races when using thin (up to micro- and nano-sized particles) or standard grain grinding. Conclusions: Using mechanical two-stage grinding of starchy raw materials and ultraviolet pretreatment of yeast, the efficiency of saccharification of starch and fermentation of wort to ethanol was increased.
Descritores: Saccharomyces cerevisiae/efeitos da radiação
Raios Ultravioleta
Leveduras/efeitos da radiação
Etanol/efeitos da radiação
-Saccharomyces/metabolismo
Amido
Temperatura
Leveduras/metabolismo
Estabilidade Enzimática
Etanol/metabolismo
Fermentação
Glucose
Amilases
Responsável: CL1.1 - Biblioteca Central


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Id: biblio-1021034
Autor: Mihálik, Daniel; Gubisová, Marcela; Kraic, Ján; Hudcovicová, Martina; Havrlentová, Michaela; Moravcíková, Jana; Glasa, Miroslav; Matusíková, Ildikó.
Título: Introduction of a synthetic Thermococcus-derived α-amlyase gene into barley genome for increased enzyme thermostability in grains
Fonte: Electron. j. biotechnol;30:1-5, nov. 2017. ilus, tab, graf.
Idioma: en.
Projeto: Slovak Research and Development Agency.
Resumo: Background: The enzymes utilized in the process of beer production are generally sensitive to higher temperatures. About 60% of them are deactivated in drying the malt that limits the utilization of starting material in the fermentation process. Gene transfer from thermophilic bacteria is a promising tool for producing barley grains harboring thermotolerant enzymes. Results: Gene for α-amylase from hydrothermal Thermococcus, optimally active at 75­85°C and pH between 5.0 and 5.5, was adapted in silico to barley codon usage. The corresponding sequence was put under control of the endosperm-specific promoter 1Dx5 and after synthesis and cloning transferred into barley by biolistics. In addition to model cultivar Golden Promise we transformed three Slovak barley cultivars Pribina, Levan and Nitran, and transgenic plants were obtained. Expression of the ~50 kDa active recombinant enzyme in grains of cvs. Pribina and Nitran resulted in retaining up to 9.39% of enzyme activity upon heating to 75°C, which is more than 4 times higher compared to non-transgenic controls. In the model cv. Golden Promise the grain α-amylase activity upon heating was above 9% either, however, the effects of the introduced enzyme were less pronounced (only 1.22 fold difference compared with non-transgenic barley). Conclusions: Expression of the synthetic gene in barley enhanced the residual α-amylase activity in grains at high temperatures.
Descritores: Sementes/enzimologia
Hordeum/enzimologia
Thermococcus/metabolismo
alfa-Amilases/metabolismo
-Sementes/genética
Sementes/microbiologia
Transformação Genética
Hordeum/genética
Hordeum/microbiologia
Cerveja
Estabilidade Enzimática
Plantas Geneticamente Modificadas/enzimologia
Clonagem Molecular
Técnicas de Transferência de Genes
alfa-Amilases/genética
Fermentação
Termotolerância
Temperatura Alta
Concentração de Íons de Hidrogênio
Responsável: CL1.1 - Biblioteca Central


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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
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-1008980
Autor: Tang, Feng; Chen, Daiwen; Yu, Bing; Luo, Yuheng; Zheng, Ping; Mao, Xiangbing; Yu, Jie; He, Jun.
Título: Improving the thermostability of Trichoderma reesei xylanase 2 by introducing disulfide bonds
Fonte: Electron. j. biotechnol;26:52-59, Mar. 2017. ilus, tab, graf.
Idioma: en.
Projeto: Fok Ying Tung Education Foundation; . "Prominent Young Scientist Fund" of Sichuan Province.
Resumo: Background: Xylanases are considered one of the most important enzymes in many industries. However, their low thermostability hampers their applications in feed pelleting, pulp bleaching, and so on. The main aim of this work was to improve the thermostability of Trichoderma ressei xylanase 2 (Xyn2) by introducing disulfide bonds between the N-terminal and α-helix and the ß-sheet core. Results: In this work, two disulfide bonds were separately introduced in the Xyn2 to connect the N-terminal and α-helix to the ß-sheet core of Xyn2. The two disulfide bonds were introduced by site-directed mutagenesis of the corresponding residues. The half-life of the mutants Xyn2C14­52 (disulfide bond between ß-sheets B2 and B3) and Xyn2C59­149 (disulfide bond between ß-sheets A5 and A6) at 60°C was improved by approximately 2.5- and 1.8-fold compared to that of the wild type Xyn2. In addition, the enzyme's resistance to alkali and acid was enhanced. Conclusion: Our results indicated that the connection of the N-terminal and α-helix to the ß-sheet core is due to the stable structure of the entire protein.
Descritores: Trichoderma/enzimologia
Xilosidases/metabolismo
Dissulfetos/metabolismo
-Espectrometria de Massas
Temperatura
Trichoderma/genética
Trichoderma/metabolismo
Xilanos/metabolismo
Xilosidases/genética
Estabilidade Enzimática
Cinética
Mutagênese Sítio-Dirigida
Concentração de Íons de Hidrogênio
Mutação
Responsável: CL1.1 - Biblioteca Central



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