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Production of xylanase by Aspergilli using alternative carbon sources: application of the crude extract on cellulose pulp biobleaching

PEIXOTO-NOGUEIRA, Simone de Carvalho; MICHELIN, Michele; BETINI, Jorge Henrique Almeida; JORGE, Joao Atilio; TERENZI, Hector Francisco; POLIZELI, Maria de Lourdes Teixeira de Moraes
Fonte: SPRINGER HEIDELBERG Publicador: SPRINGER HEIDELBERG
Tipo: Artigo de Revista Científica
ENG
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The ability of xylanolytic enzymes produced by Aspergillus fumigatus RP04 and Aspergillus niveus RP05 to promote the biobleaching of cellulose pulp was investigated. Both fungi grew for 4-5 days in liquid medium at 40A degrees C, under static conditions. Xylanase production was tested using different carbon sources, including some types of xylans. A. fumigatus produced high levels of xylanase on agricultural residues (corncob or wheat bran), whereas A. niveus produced more xylanase on birchwood xylan. The optimum temperature of the xylanases from A. fumigatus and A. niveus was around 60-70A degrees C. The enzymes were stable for 30 min at 60A degrees C, maintaining 95-98% of the initial activity. After 1 h at this temperature, the xylanase from A. niveus still retained 85% of initial activity, while the xylanase from A. fumigatus was only 40% active. The pH optimum of the xylanases was acidic (4.5-5.5). The pH stability for the xylanase from A. fumigatus was higher at pH 6.0-8.0, while the enzyme from A. niveus was more stable at pH 4.5-6.5. Crude enzymatic extracts were used to clarify cellulose pulp and the best result was obtained with the A. niveus preparation, showing kappa efficiency around 39.6% as compared to only 11.7% for that of A. fumigatus.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Conselho Nacional de Desenvolvimento Cientfico e Tecnologico (CNPq)

Molecular characterization of the Aspergillus nidulans fbxA encoding an F-box protein involved in xylanase induction

Colabardini, Ana Cristina; Humanes, Ana Carolina; Gouvea, Paula Fagundes; Savoldi, Marcela; Goldman, Maria Helena S.; von Zeska Kress, Marcia Regina; Bayram, Oezguer; de Castro Oliveira, Juliana Velasco; Gomes, Marcelo Damario; Braus, Gerhard H.; Goldman,
Fonte: ACADEMIC PRESS INC ELSEVIER SCIENCE; SAN DIEGO Publicador: ACADEMIC PRESS INC ELSEVIER SCIENCE; SAN DIEGO
Tipo: Artigo de Revista Científica
ENG
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The filamentous fungus Aspergillus nidulans has been used as a fungal model system to study the regulation of xylanase production. These genes are activated at transcriptional level by the master regulator the transcriptional factor XInR and repressed by carbon catabolite repression (CCR) mediated by the wide-domain repressor CreA. Here, we screened a collection of 42 A. nidulans F-box deletion mutants grown either in xylose or xylan as the single carbon source in the presence of the glucose analog 2-deoxy-D-glucose, aiming to identify mutants that have deregulated xylanase induction. We were able to recognize a null mutant in a gene (fbxA) that has decreased xylanase activity and reduced xInA and xInD mRNA accumulation. The Delta fbxA mutant interacts genetically with creAd-30, creB15, and creC27 mutants. FbxA is a novel protein containing a functional F-box domain that binds to Skp1 from the SCF-type ligase. Blastp analysis suggested that FbxA is a protein exclusive from fungi, without any apparent homologs in higher eukaryotes. Our work emphasizes the importance of the ubiquitination in the A. nidulans xylanase induction and CCR. The identification of FbxA provides another layer of complexity to xylanase induction and CCR phenomena in filamentous fungi. (C) 2011 Elsevier Inc. All rights reserved.; Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)...

Production of a xylose-stimulated beta-glucosidase and a cellulase-free thermostable xylanase by the thermophilic fungus Humicola brevis var. thermoidea under solid state fermentation

Masui, Douglas Chodi; Zimbardi, Ana Lucia Ribeiro Latorre; Souza, Flavio Henrique Moreira de; Guimarães, Luis Henrique Souza; Furriel, Rosa dos Prazeres Melo; Jorge, Joao Atilio
Fonte: SPRINGER; NEW YORK Publicador: SPRINGER; NEW YORK
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Humicola brevis var. thermoidea cultivated under solid state fermentation in wheat bran and water (1:2 w/v) was a good producer of beta-glucosidase and xylanase. After optimization using response surface methodology the level of xylanase reached 5,791.2 +/- A 411.2 U g(-1), while beta-glucosidase production was increased about 2.6-fold, reaching 20.7 +/- A 1.5 U g(-1). Cellulase levels were negligible. Biochemical characterization of H. brevis beta-glucosidase and xylanase activities showed that they were stable in a wide pH range. Optimum pH for beta-glucosidase and xylanase activities were 5.0 and 5.5, respectively, but the xylanase showed 80 % of maximal activity when assayed at pH 8.0. Both enzymes presented high thermal stability. The beta-glucosidase maintained about 95 % of its activity after 26 h in water at 55 A degrees C, with half-lives of 15.7 h at 60 A degrees C and 5.1 h at 65 A degrees C. The presence of xylose during heat treatment at 65 A degrees C protected beta-glucosidase against thermal inactivation. Xylanase maintained about 80 % of its activity after 200 h in water at 60 A degrees C. Xylose stimulated beta-glucosidase activity up to 1.7-fold, at 200 mmol L-1. The notable features of both xylanase and beta-glucosidase suggest that H. brevis crude culture extract may be useful to compose efficient enzymatic cocktails for lignocellulosic materials treatment or paper pulp biobleaching.; Conselho de Desenvolvimento Cientifico e Tecnologico (CNPq); Conselho de Desenvolvimento Cientifico e Tecnologico (CNPq); Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP); Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES); Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)

Production of xylanase and beta-xylosidase from autohydrolysis liquor of corncob using two fungal strains

Michelin, Michele; Polizeli, Maria de Lourdes Teixeira de Moraes; Ruzene, Denise S.; Silva, Daniel P.; Ruiz, Hector A.; Vicente, Antonio A.; Jorge, Joao Atilio; Terenzi, Hector Francisco; Teixeira, Jose A.
Fonte: SPRINGER; NEW YORK Publicador: SPRINGER; NEW YORK
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
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Agroindustrial residues are materials often rich in cellulose and hemicellulose. The use of these substrates for the microbial production of enzymes of industrial interest is mainly due to their high availability associated with their low cost. In this work, corncob (CCs) particles decomposed to soluble compounds (liquor) were incorporated in the microbial growth medium through autohydrolysis, as a strategy to increase and undervalue xylanase and beta-xylosidase production by Aspergillus terricola and Aspergillus ochraceus. The CCs autohydrolysis liquor produced at 200 A degrees C for 5, 15, 30 or 50 min was used as the sole carbon source or associated with untreated CC. The best condition for enzyme synthesis was observed with CCs submitted to 30 min of autohydrolysis. The enzymatic production with untreated CCs plus CC liquor was higher than with birchwood xylan for both microorganisms. A. terricola produced 750 total U of xylanase (144 h cultivation) and 30 total U of beta-xylosidase (96-168 h) with 0.75% untreated CCs and 6% CCs liquor, against 650 total U of xylanase and 2 total U of beta-xylosidase in xylan; A. ochraceus produced 605 total U of xylanase and 56 total U of beta-xylosidase (168 h cultivation) with 1% untreated CCs and 10% CCs liquor against 400 total U of xylanase and 38 total U of beta-xylosidase in xylan. These results indicate that the treatment of agroindustrial wastes through autohydrolysis can be a viable strategy in the production of high levels of xylanolytic enzymes.; State of Sao Paulo Research Foundation (FAPESP)...

Screening and Production Study of Microbial Xylanase Producers from Brazilian Cerrado

Alves-Prado, Heloiza Ferreira; Pavezzi, Fabiana Carina; Ribeiro Leite, Rodrigo Simoes; de Oliveira, Valeria Maia; Sette, Lara Duraes; DaSilva, Roberto
Fonte: Humana Press Inc Publicador: Humana Press Inc
Tipo: Artigo de Revista Científica Formato: 333-346
ENG
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Hemicelluloses are polysaccharides of low molecular weight containing 100 to 200 glycosidic residues. In plants, the xylans or the hemicelluloses are situated between the lignin and the collection of cellulose fibers underneath. The xylan is the most common hemicellulosic polysaccharide in cell walls of land plants, comprising a backbone of xylose residues linked by beta-1,4-glycosidic bonds. So, xylanolytic enzymes from microorganism have attracted a great deal of attention in the last decade, particularly because of their biotechnological characteristics in various industrial processes, related to food, feed, ethanol, pulp, and paper industries. A microbial screening of xylanase producer was carried out in Brazilian Cerrado area in Selviria city, Mato Grosso do Sul State, Brazil. About 50 bacterial strains and 15 fungal strains were isolated from soil sample at 35 A degrees C. Between these isolated microorganisms, a bacterium Lysinibacillus sp. and a fungus Neosartorya spinosa as good xylanase producers were identified. Based on identification processes, Lysinibacillus sp. is a new species and the xylanase production by this bacterial genus was not reported yet. Similarly, it has not reported about xylanase production from N. spinosa. The bacterial strain P5B1 identified as Lysinibacillus sp. was cultivated on submerged fermentation using as substrate xylan...

Production, purification and characterization of a minor form of xylanase from Aspergillus versicolor

Carmona, E. C.; Fialho, M. B.; Buchgnani, E. B.; Coelho, G. D.; Brocheto-Braga, M. R.; Jorge, J. A.
Fonte: Elsevier B.V. Publicador: Elsevier B.V.
Tipo: Artigo de Revista Científica Formato: 359-364
ENG
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A strain of Aspergillus versicolor produces a xylanolytic complex containing two components, the minor component being designated xylanase II. The highest production of xylanase II was observed in cultures grown for 5 days in 1% wheat bran as carbon source, at pH 6.5. Xylanase II was purified 28-fold by DEAE-Sephadex and HPLC GF-5 10 gel filtration. Xylanase II was a monomeric glycoprotein, exhibiting a molecular mass of 32 kDa with 14.1% of carbohydrate content. Optimal pH and temperature values for the enzyme activity were about 6.0-7.0 and 55 degreesC, respectively. Xylanase II thermoinactivation at 50degreesC showed a biphasic curve. The ions Hg2+, Cu2+ and the detergent SDS were strong inhibitors, while Mn2+ ions and dithiothreitol were stimulators of the enzyme activity. The enzyme was specific for xylans, showing higher specific activity on birchwood xylan. The Michaelis-Menten constant (K-m) for birchwood xylan was estimated to be 2.3 mg ml(-1) while maximal velocity (V-max) was 233.1 mumol mg(-1) min(-1) of protein. The hydrolysis of oat spell xylan released only xylooligosaccharides. Published by Elsevier Ltd.

Xylanase production by Aspergillus awamori under solid state fermentation conditions on tomato pomace

Umsza-Guez, Marcelo A.; Díaz, Ana B.; Ory, Ignacio de; Blandino, Ana; Gomes, Eleni; Caro, Ildefonso
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: 1585-1597
ENG
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); In this work, tomato pomace, a waste abundantly available in the Mediterranean and other temperate climates agro-food industries, has been used as raw material for the production of some hydrolytic enzymes, including xylanase, exo-polygalacturonase (exo-PG), cellulase (CMCase) and α-amylase. The principal step of the process is the solid state fermentation (SSF) of this residue by Aspergillus awamori. In several laboratory experiments, maximum xylanase and exo-PG activities were measured during the first days of culture, reaching values around 100 and 80 IU/gds (international units of enzyme activity per gram of dried solid), respectively. For CMCase and α-amylase production remained almost constant along fermentation, with average values of 19 and 21.5 IU/gds, respectively. Experiments carried out in a plate-type bioreactor at lab scale showed a clear positive effect of aeration on xylanase and CMCase, while the opposite was observed for exo-PG and α-amylase. In general, xylanase was the enzyme produced in higher levels, thus the optimum conditions for the determination of the enzyme activity was characterized. The xylanase activity shows an optimum pH of 5 and an optimum temperature of 50 ºC. The enzyme is activated by Mg2+...

Xylanase production by Bacillus circulans D1 using maltose as carbon source

Bocchini, D. A.; Gomes, E.; Da Silva, R.
Fonte: Humana Press Inc Publicador: Humana Press Inc
Tipo: Artigo de Revista Científica Formato: 29-37
ENG
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Bacillus circulans D1 is a good producer of extracellular thermostable xylanase. Xylanase production in different carbon sources was evaluated and the enzyme synthesis was induced by various carbon sources. It was found that D-maltose is the best inducer of the enzyme synthesis ( 7.05 U/ mg dry biomass at 48 h), while D-glucose and D-arabinose lead to the production of basal levels of xylanase. The crude enzyme solution is free of cellulases, even when the microorganism was cultivated in a medium with D-cellobiose. When oat spelt xylan was supplemented with D-glucose, the repressive effect of this sugar on xylanase production was observed at 24 h, only when used at 5.0 g/ L, leading to a reduction of 60% on the enzyme production. on the other hand, when the xylan medium was supplemented with D- xylose ( 3.0 or 5.0 g/ L), this effect was more evident ( 80 and 90% of reduction on the enzyme production, respectively). Unlike that observed in the xylan medium, glucose repressed xylanase production in the maltose medium, leading to a reduction of 55% on the enzyme production at 24 h of cultivation. Xylose, at 1.0 g/ L, induced xylanase production on the maltose medium. on this medium, the repressive effect of xylose, at 3.0 or 5.0 g/ L...

Triagem, seleção, produção e caracterização da enzima xilanase a partir de leveduras silvestres; Screening, selection, production and characterization of the enzyme xylanase from wild yeasts

Felipe Bastos Motta
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 24/04/2008 PT
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A endo-1,4-ß-xilanase (E.C. 3.2.1.8), comumente chamada de xilanase, possui grande aplicação em diferentes tipos de indústrias tais como a de ração animal, alimentos, têxteis, de papel, de produção de etanol a partir de biomassa, entre outras. Isso se deve ao fato de que esta enzima atua na hidrólise da xilana, o segundo mais abundante polissacarídeo encontrado na natureza, que está presente ligado a hemicelulose da parece celular de plantas. O objetivo deste trabalho foi selecionar, através do método de screening em placas de Petri, e avaliar a atividade enzimática de leveduras silvestres isoladas de diversas regiões do Brasil (Mata Atlântica, Floresta Amazônica, Cerrado e Pantanal) quanto à produção de xilanase. Para o screening em placas, utilizou-se um meio de cultura no qual a única fonte de carbono era a xilana para induzir a produção da enzima. De um total de 349 microrganismos analisados, foram obtidas 84 cepas produtoras, porém somente 37 possuíam um índice de relação enzimática (diâmetro do halo descolorido / diâmetro da colônia) maior que 2,5. Em função deste resultado prosseguiu-se com a seleção dos melhores microrganismos para a produção da enzima em meio líquido. Após observações preliminares apenas 9 cepas obtiveram um crescimento satisfatório em meio líquido a 30ºC e 150 rpm. Estes foram avaliados em dois meios de culturas diferentes em relação à atividade enzimática do caldo enzimático à 50ºC por 5 min em shaker. Dentre estes...

Produção, purificação e caracterização de xilanase termoestável produzida por Cryptococcus flavescens e expressão em Pichia pastoris; Production, purification and characterization of thermostable xylanase produced by Cryptococcus flavescens and expression in Pichia pastoris

Cristiane Conte Paim de Andrade
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 23/05/2014 PT
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Xilanases são enzimas que hidrolisam as ligações glicosídicas entre as unidades de xilose que compõem a xilana, o principal constituinte hemicelulósico. Devido à grande disponibilidade desse tipo de material na natureza, as xilanases podem ser empregadas em diversos ramos, como nas indústrias têxtil, de alimentos e de rações, na bioconversão de resíduos lignocelulósicos, no clareamento de papel e polpa, e no tratamento de resíduos. Visando descrever novas enzimas para futuras aplicações, este trabalho teve como objetivo purificar e caracterizar a xilanase produzida pelo basidiomiceto Cryptococcus sp. LEB-AY10, uma levedura previamente isolada da Mata Atlântica e selecionada pela produção de enzima termoestável. Para tanto, o micro-organismo foi inicialmente identificado em nível de espécie e depositado como C. flavescens LEB-AY10 (CCT 7725); em sequência, foi estudada a produção da enzima utilizando, como substrato, bagaço de cana-de-açúcar, pré-tratado por explosão a vapor em três diferentes condições, bem como suas respectivas frações solúveis, e suplementados com melaço ou componentes sintéticos. Tendo sido definida a metodologia de tratamento do bagaço, técnicas de planejamento experimental foram utilizadas para estudar a influência das variáveis de cultivo e aumentar a atividade da xilanase produzida. Nas condições otimizadas...

Bleach boosting and direct brightening by multiple xylanase treatments during peroxide bleaching of kraft pulps

Wong, Ken K. Y.; Martin, Lori A.; Gama, F. M.; Saddler, John N.; De Jong, Ed
Fonte: John Wiley & Sons Publicador: John Wiley & Sons
Tipo: Artigo de Revista Científica
Publicado em /05/1997 ENG
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The effects of multiple xylanase treatments were assessed during the peroxide bleaching of three pulps: Douglas-fir (kraft); Western hemlock (oxygen delignified kraft); and trembling Aspen (kraft). The addition of a xylanase treatment stage, either before or after the peroxide bleaching stage(s), resulted in the enhanced brightening of all pulps. A higher brightness was achieved using two enzyme treatments, one before and one after the peroxide stage(s). Both bleach boosting and direct brightening seemed to contribute to the enhancement of peroxide bleaching. Compared to xylanase prebleaching, xylanase posttreatment of the peroxide bleached pulps solubilized less lignin and chromophores and made smaller amounts of these materials alkaline soluble. Nevertheless, the final brightness achieved by xylanase posttreatment was similar or superior to that achieved with xylanase prebleaching of the corresponding unbleached pulps.

A new strategy for xylanase production using wheat straw autohydrolysis liquor as substrate

Michelin, Michele; Polizeli, Maria de Lourdes T. M.; Ruzene, Denise S.; Silva, Daniel Pereira da; Vicente, A. A.; Jorge, João A.; Terenzi, Héctor F.; Teixeira, J. A.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Conferência ou Objeto de Conferência
Publicado em /09/2008 ENG
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Agro-industrial residues are lignocellulosic materials with a high content of cellulose, hemicellulose and lignin. If such residues can be produced in bioprocesses (e.g. xylanase production) there is an attractive possibility of their integral use in biotechnological processes. In general, xylanase biosynthesis is induced by its substrate – xylan, but the high xylan content of some wastes such as corn cobs and wheat bran makes them an accessible and cheap source of inducers. Another alternative to improve the xylanase production, which is the main goal of this work, is the treatment of lignocellulosic materials in autohydrolysis processes which, under optimized conditions, lead to the solubilization of hemicelluloses (liquid phase, liquor) that may be favorable to xylanase production. The inclusion of these components in the nutrient medium composition can be a strategy to optimize the microbial xylanase biosynthesis. The best conditions for xylanase production were observed when the microorganism was cultivated in birchwood xylan for 6 days; however, satisfactory results were obtained using a combination of 1% wheat bran with 2% or 10% autohydrolysis liquor, for 5 days fermentation, once the xylanase production was around 86-87% of production with xylan. Besides...

Production of xylanase and β-xylosidase from autohydrolysis liquor of corncob using two fungal strains

Michelin, Michele; Polizeli, Maria de Lourdes T. M.; Ruzene, Denise S.; Silva, Daniel Pereira da; Ruiz, Héctor A.; Vicente, A. A.; Jorge, João A.; Terenzi, Héctor F.; Teixeira, J. A.
Fonte: Springer Verlag Publicador: Springer Verlag
Tipo: Artigo de Revista Científica
Publicado em //2012 ENG
Relevância na Pesquisa
37.41247%
Agroindustrial residues are materials often rich in cellulose and hemicellulose. The use of these substrates for the microbial production of enzymes of industrial interest is mainly due to their high availability associated with their low cost. In this work, corncob (CCs) particles decomposed to soluble compounds (liquor) were incorporated in the microbial growth medium through autohydrolysis, as a strategy to increase and undervalue xylanase and b-xylosidase production by Aspergillus terricola and Aspergillus ochraceus. The CCs autohydrolysis liquor produced at 200 C for 5, 15, 30 or 50 min was used as the sole carbon source or associated with untreated CC. The best condition for enzyme synthesis was observed with CCs submitted to 30 min of autohydrolysis. The enzymatic production with untreated CCs plus CC liquor was higher than with birchwood xylan for both microorganisms. A. terricola produced 750 total U of xylanase (144 h cultivation) and 30 total U of b-xylosidase (96–168 h) with 0.75% untreated CCs and 6% CCs liquor, against 650 total U of xylanase and 2 total U of b-xylosidase in xylan; A. ochraceus produced 605 total U of xylanase and 56 total U of b-xylosidase (168 h cultivation) with 1% untreated CCs and 10% CCs liquor against 400 total U of xylanase and 38 total U of b-xylosidase in xylan. These results indicate that the treatment of agroindustrial wastes through autohydrolysis can be a viable strategy in the production of high levels of xylanolytic enzymes.

Comparison between continuous and batch processing to produce xylanase by penicillium canescens 10-10c

Bakri,Y.; Akeed,Y.; Thonart,P.
Fonte: Brazilian Society of Chemical Engineering Publicador: Brazilian Society of Chemical Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2012 EN
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Penicillium canescens 10-10c strain was cultivated on barley straw hydrolysate as a soluble nutrient source and as inducer for xylanase production. Barley straw hydrolysate was obtained by treatment of barley straw with NaOH or hot water. In shake flask cultures, NaOH treatment was found to increase the biomass production, but was not accompanied by an increase in xylanase production. The best xylanase production (54 U/ml) was observed on hydrolyzed extract from barley straw treated with hot water (100 ºC) for 3 hours. Enzyme production was further improved by scaling up the cultivation process to a 3-L stirred tank bioreactor. For batch cultivations in the bioreactor, the maximum xylanase productivity reached 1.31 and 0.46 U/ml/h, respectively, after 96 and 168 hours of cultivation. However, xylanase productivity reached 3.46 U/ml/h in the continuous culture. These results suggest that xylanase can be produced efficiently by Penicillium canescens 10-10c in continuous culture from an inexpensive source such as barley straw hydrolysate.

Induction of xylanase in thermophilic fungi Scytalidium thermophilum and Sporotrichum thermophile

Joshi,Chetna; Khare,Sunil Kumar
Fonte: Instituto de Tecnologia do Paraná - Tecpar Publicador: Instituto de Tecnologia do Paraná - Tecpar
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2012 EN
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Regulation of xylanase production in two thermophilic fungi Scytalidium thermophilum and Sporotrichum thermophile was investigated. The expression of xylanase was found to be inducible in both the cases. Various carbon sources were tested so as to identify the inducers. Soy flour and oat spelt xylan induced maximum level of xylanase in Scytalidium thermophilum and Sporotrichum thermophile respectively. Induction of xylanase in Scytalidium thermophilum led to simultaneous induction of cellulase. The zymography of enzyme preparations revealed that different carbon sources caused differential expression of multiple isoforms of xylanase in Scytalidium thermophilum, but same isoforms were expressed by Sporotrichum thermophile irrespective of the carbon source used.

Xylanase production by Trichoderma harzianum rifai by solid state fermentation on sugarcane bagasse

Rezende,Maria Inês; Barbosa,Aneli de Melo; Vasconcelos,Ana Flora Dalberto; Endo,Asae Sakurada
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2002 EN
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Sugarcane bagasse was used as substrate for xylanase production by means of a strain of Trichoderma harzianum Rifai isolated from decaying Aspidosperma sp. (peroba) wood. The bagasse was washed, dried, milled and wetted with minimal salts medium and the cultures grown at 28 ± 2ºC for 7 days. Two extraction methods were tested for enzyme recovery: (A) Tween 80, 0.1% (v/v), in physiological saline, and (B) 50mM sodium acetate buffer, pH 5.0, under agitation (180rpm) for 15, 30 and 60min. After a single extraction, both extraction methods recovered an average of 15U/ml of xylanase activity, independent on the time of shaking. A second and third extraction recovered 10.4 and 6.6U/ml xylanase, respectively. The effect of volume size for extraction, and sugarcane bagasse concentration, on xylanase production were also investigated. The growth profile of Trichoderma harzianum was followed over 20 days on 14% (w/v) bagasse, and highest xylanase activity (288U/ml) appeared on the seventh day. The enzymatic extract after precipitation with ammonium sulphate was submitted to electrophoresis on polyacrylamide gels and showed 4 protein-staining bands, one of which exhibited xylanase activity.

Production and characterization of an enzyme complex from a new strain of Clostridium thermocellum with emphasis on its xylanase activity

Vieira,Werner Bessa; Moreira,Leonora Rios de Souza; Monteiro Neto,Amadeu; Ferreira Filho,Edivaldo Ximenes
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2007 EN
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A new bacterial strain (ISO II) was isolated from manure cow and identified as phylogenetically close to the thermophilic cellulolytic bacterium Clostridium thermocellum. The new strain produced extracellular xylanase, pectinase, mannanase and cellulase activities when grown in liquid culture medium containing banana stem as carbon source. The enzyme production profile after growth on banana stem showed that xylanase and cellulase activities were detected in different incubation periods. An enzyme complex containing xylanase, cellulase and mannanase activities was isolated from culture supernatant samples of strainISO II. The complex was partially purified by ultrafiltration and gel filtration chromatography on Sephacryl S-300. Zymogram analysis after SDS-PAGE presented at least 05 subunits with xylanase activity. The enzyme showed single protein and xylanase activity bands after electrophoresis under non-denaturing conditions. The hydrolysis of xylan was optimal at temperature range of 55-75ºC and pH 6.0. Xylanase activity was quite stable at 65ºC, retaining 80% of its original activity after 12 h incubation. The apparent Km values, using insoluble and soluble arabinoxylans as substrates, were 1.54 and 11.53 mg/mL, respectively. Xylanase was activated by dithiothreitol...

Xylanase production with xylan rich lignocellulosic wastes by a local soil isolate of Trichoderma viride

Goyal,Meenakshi; Kalra,K.L.; Sareen,V.K.; Soni,G.
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2008 EN
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In the present study, cultural and nutritional conditions for enhanced production of xylanase by a local soil isolate of Trichoderma viride, using various lignocellulosic substrates in submerged culture fermentation have been optimized. Of the lignocellulosics used, maize straw was the best inducer followed by jowar straw for xylanase production. The highest activity achieved was between 14 to 17 days of fermentation. A continuous increase in xylanase production was observed with increasing level of lignocellulosics in the medium and highest activity was observed with maize straw at 5% level. Xylanase production with higher levels of lignocellulosics (3 to 5%) of maize, jowar and barseem was found to be higher as compared to that with commercial xylan as carbon source. Sodium nitrate was the best nitrogen source among the six sources used. Maximum xylanase production was achieved with initial medium pH of 3.5-4.0 and incubation temperature of 25ºC.The enzyme preparation was effective in bringing about saccharification of different lignocellulosics. The xylanase production could be further improved by using alkali treated straw as carbon source.

Xylanase production by Aspergillus awamori under solid state fermentation conditions on tomato pomace

Umsza-Guez,Marcelo A.; Díaz,Ana B.; Ory,Ignacio de; Blandino,Ana; Gomes,Eleni; Caro,Ildefonso
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2011 EN
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In this work, tomato pomace, a waste abundantly available in the Mediterranean and other temperate climates agro-food industries, has been used as raw material for the production of some hydrolytic enzymes, including xylanase, exo-polygalacturonase (exo-PG), cellulase (CMCase) and α-amylase. The principal step of the process is the solid state fermentation (SSF) of this residue by Aspergillus awamori. In several laboratory experiments, maximum xylanase and exo-PG activities were measured during the first days of culture, reaching values around 100 and 80 IU/gds (international units of enzyme activity per gram of dried solid), respectively. For CMCase and α-amylase production remained almost constant along fermentation, with average values of 19 and 21.5 IU/gds, respectively. Experiments carried out in a plate-type bioreactor at lab scale showed a clear positive effect of aeration on xylanase and CMCase, while the opposite was observed for exo-PG and α-amylase. In general, xylanase was the enzyme produced in higher levels, thus the optimum conditions for the determination of the enzyme activity was characterized. The xylanase activity shows an optimum pH of 5 and an optimum temperature of 50 ºC. The enzyme is activated by Mg2+...

Molecular characterization of a Xylanase-producing fungus isolated from fouled soil

Sakthiselvan,Punniavan; Naveena,Balakrishnan; Partha,Nagarajan
Fonte: Sociedade Brasileira de Microbiologia Publicador: Sociedade Brasileira de Microbiologia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
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Xylanase (EC 3. 2. 1. 8), hydrolyzes xylo-oligosaccharides into D-xylose and required for complete hydrolysis of native cellulose and biomass conversion. It has broad range of applications in the pulp and paper, pharmaceutical and Agri-food industries. Fifty fungal species were isolated from the fouled soil around an oil refinery and screened for the production of xylanase enzyme by enrichment culture techniques. The isolated fungal strain was identified as Hypocrea lixii SS1 based on the results of biochemical tests and 18s rRNA sequencing. The phylogenetic tree was constructed using the MEGA 5 software. Further, Hypocrea lixii SS1 was tested for the ability to utilize the sunflower oil sludge (waste from the oil industry) as the sole carbon source for xylanase production. The growth characteristics of Hypocrea lixii SS1 were also studied and maximum growth was found on the 7th day of incubation. The fungus showed a remarkable xylanase production of 38.9 U/mL. Xylanase was purified using a combination of 0-50% NH4SO2 precipitation, DEAE-sepharose and Sephacryl S-200 chromatography. Single peak obtained in RP-HPLC confirms the purity of xylanase. Further the enzyme produced was affirmed as xylanase with its molecular weight (29 kDa) using SDS-PAGE.