Supramolecular organization of photosynthetic membrane proteins in the chlorosome-containing bacterium Chloroflexus aurantiacus

Czech Academy of Sciences Publication Activity Database

Bína, David; Gardian, Zdenko; Vácha, František; Litvín, Radek

2014-01-01

Roč. 122, č. 1 (2014), s. 13-21 ISSN 0166-8595 R&D Projects: GA ČR GBP501/12/G055; GA ČR(CZ) GAP205/11/1164 Institutional support: RVO:60077344 Keywords : Photosynthesis * LH1 * Chlorosome * Chloroflexus aurantiacus Subject RIV: BO - Biophysics Impact factor: 3.502, year: 2014

Xylanases of thermophilic bacteria from Icelandic hot springs

Energy Technology Data Exchange (ETDEWEB)

Pertulla, M; Raettoe, M; Viikari, L [VTT, Biotechnical Lab., Espoo (Finland); Kondradsdottir, M [Dept. of Biotechnology, Technological Inst. of Iceland, Reykjavik (Iceland); Kristjansson, J K [Dept. of Biotechnology, Technological Inst. of Iceland, Reykjavik (Iceland) Inst. of Biotechnology, Iceland Univ., Reykjavik (Iceland)

1993-02-01

Thermophilic, aerobic bacteria isolated from Icelandic hot springs were screened for xylanase activity. Of 97 strains tested, 14 were found to be xylanase positive. Xylanase activities up to 12 nkat/ml were produced by these strains in shake flasks on xylan medium. The xylanases of the two strains producing the highest activities (ITI 36 and ITI 283) were similar with respect to temperature and pH optima (80deg C and pH 8.0). Xylanase production of strain ITI 36 was found to be induced by xylan and xylose. Xylanase activity of 24 nkat/ml was obtained with this strain in a laboratory-scale-fermentor cultivation on xylose medium. [beta]-Xylosidase activity was also detected in the culture filtrate. The thermal half-life of ITI 36 xylanase was 24 h at 70deg C. The highest production of sugars from hydrolysis of beech xylan was obtained at 70deg C, although xylan depolymerization was detected even up to 90deg C. (orig.).

Thermophilic xylanases: from bench to bottle.

Science.gov (United States)

Basit, Abdul; Liu, Junquan; Rahim, Kashif; Jiang, Wei; Lou, Huiqiang

2018-01-17

Lignocellulosic biomass is a valuable raw material. As technology has evolved, industrial interest in new ways to take advantage of this raw material has grown. Biomass is treated with different microbial cells or enzymes under ideal industrial conditions to produce the desired products. Xylanases are the key enzymes that degrade the xylosidic linkages in the xylan backbone of the biomass, and commercial enzymes are categorized into different glycoside hydrolase families. Thermophilic microorganisms are excellent sources of industrially relevant thermostable enzymes that can withstand the harsh conditions of industrial processing. Thermostable xylanases display high-specific activity at elevated temperatures and distinguish themselves in biochemical properties, structures, and modes of action from their mesophilic counterparts. Natural xylanases can be further improved through genetic engineering. Rapid progress with genome editing, writing, and synthetic biological techniques have provided unlimited potential to produce thermophilic xylanases in their natural hosts or cell factories including bacteria, yeasts, and filamentous fungi. This review will discuss the biotechnological potential of xylanases from thermophilic microorganisms and the ways they are being optimized and produced for various industrial applications.

Microbial xylanases: engineering, production and industrial applications.

Science.gov (United States)

Juturu, Veeresh; Wu, Jin Chuan

2012-01-01

Enzymatic depolymerization of hemicellulose to monomer sugars needs the synergistic action of multiple enzymes, among them endo-xylanases (EC 3.2.1.8) and β-xylosidases (EC 3.2.1.37) (collectively xylanases) play a vital role in depolymerizing xylan, the major component of hemicellulose. Recent developments in recombinant protein engineering have paved the way for engineering and expressing xylanases in both heterologous and homologous hosts. Functional expression of endo-xylanases has been successful in many hosts including bacteria, yeasts, fungi and plants with yeasts being the most promising expression systems. Functional expression of β-xylosidases is more challenging possibly due to their more complicated structures. The structures of endo-xylanases of glycoside hydrolase families 10 and 11 have been well elucidated. Family F/10 endo-xylanases are composed of a cellulose-binding domain and a catalytic domain connected by a linker peptide with a (β/α)8 fold TIM barrel. Family G/11 endo-xylanases have a β-jelly roll structure and are thought to be able to pass through the pores of hemicellulose network owing to their smaller molecular sizes. The structure of a β-D-xylosidase belonging to family 39 glycoside hydrolase has been elucidated as a tetramer with each monomer being composed of three distinct regions: a catalytic domain of the canonical (β/α)8--TIM barrel fold, a β-sandwich domain and a small α-helical domain with the enzyme active site that binds to D-xylooligomers being present on the upper side of the barrel. Glycosylation is generally considered as one of the most important post-translational modifications of xylanases, but a few examples showed functional expression of eukaryotic xylanases in bacteria. The optimal ratio of these synergistic enzymes is very important in improving hydrolysis efficiency and reducing enzyme dosage but has hardly been addressed in literature. Xylanases have been used in traditional fields such as food, feed

Characterization of Xylanase Streptomyces spp. SKK1-8

Directory of Open Access Journals (Sweden)

ANJA MERYANDINI

2006-12-01

Full Text Available Streptomyces spp. SKK1-8 producing xylanase was isolated from soil sample from Sukabumi West Java. The xylanase have an optimum condition at pH 6 and 50 °C. Addition of 5 mM Cu2+ decreased the xylanase activity up to about 77%, whereas not by other cations. The xylanase was stable at 3 °C for 48 hours, and the enzyme half lifetime was 1 hour 45 minute at 50 °C. This xylanase showed the highest activity on oatspelt xylan, and their molecular masses were estimated approximately 16.80, 15.21, and 13.86 kDa. HPLC analysis showed that xylosa and arabinosa were the main hydrolytic product of birchwood xylan.

Xylanases and Their Applications in Baking Industry

Directory of Open Access Journals (Sweden)

Masood Sadiq Butt

2008-01-01

Full Text Available Xylan is the second most abundant polysaccharide and a major component of plant cell wall. Cereal xylans contain large quantities of L-arabinose and are therefore, often referred to as arabinoxylans. Xylanases are hydrolytic enzymes, which randomly cleave the β-1,4 backbone of this complex plant cell wall polysaccharide. Different species of Aspergillus and Trichoderma produce these enzymes. Xylanases are of great value in baking as they have been found to improve the bread volume, crumb structure and reduce stickiness. When xylanases are used at optimum levels, they play a significant role in increasing shelf life of bread and reduce bread staling. There is an increasing trend in baking industry towards the application of xylanases in bread production. This review discusses the application of xylanase in the bakery industry, alone and in combination with other enzymes when it shows synergism in the action with them.

Production and characterization of xylanase from Thielaviopsis basicola

Energy Technology Data Exchange (ETDEWEB)

Ghosh, V K; Deb, J K

1988-08-01

The black rot fungus Thielaviopsis basicola has the ability to grow on cellulosic biomass, producing xylanase. Of the four cellulosic substrates tested, rice straw was found to be the best for production of xylanase. A xylanase activity of 34 U/ml was obtained with rice straw which was more than three times that obtained with larchwood xylan. The ..beta..-xylosidase activities obtained with these two substrates were 0.05 U/ml and 0.016 U/ml respectively. Both enzymes are active at pH 5 but the temperature optima of xylanase and ..beta..-xylosidase activities are 60/sup 0/C and 40/sup 0/C respectively. The xylanase activity is stable over a pH range of 4-8 but the stability towards temperature falls sharply above 50/sup 0/C.

The xylanase inhibitor TAXI-III counteracts the necrotic activity of a Fusarium graminearum xylanase in vitro and in durum wheat transgenic plants.

Science.gov (United States)

Moscetti, Ilaria; Faoro, Franco; Moro, Stefano; Sabbadin, Davide; Sella, Luca; Favaron, Francesco; D'Ovidio, Renato

2015-08-01

The xylanase inhibitor TAXI-III has been proven to delay Fusarium head blight (FHB) symptoms caused by Fusarium graminearum in transgenic durum wheat plants. To elucidate the molecular mechanism underlying the capacity of the TAXI-III transgenic plants to limit FHB symptoms, we treated wheat tissues with the xylanase FGSG_03624, hitherto shown to induce cell death and hydrogen peroxide accumulation. Experiments performed on lemmas of flowering wheat spikes and wheat cell suspension cultures demonstrated that pre-incubation of xylanase FGSG_03624 with TAXI-III significantly decreased cell death. Most interestingly, a reduced cell death relative to control non-transgenic plants was also obtained by treating, with the same xylanase, lemmas of TAXI-III transgenic plants. Molecular modelling studies predicted an interaction between the TAXI-III residue H395 and residues E122 and E214 belonging to the active site of xylanase FGSG_03624. These results provide, for the first time, clear indications in vitro and in planta that a xylanase inhibitor can prevent the necrotic activity of a xylanase, and suggest that the reduced FHB symptoms on transgenic TAXI-III plants may be a result not only of the direct inhibition of xylanase activity secreted by the pathogen, but also of the capacity of TAXI-III to avoid host cell death. © 2014 BSPP AND JOHN WILEY & SONS LTD.

Analysis of functional xylanases in xylan degradation by Aspergillus niger E-1 and characterization of the GH family 10 xylanase XynVII.

Science.gov (United States)

Takahashi, Yui; Kawabata, Hiroaki; Murakami, Shuichiro

2013-01-01

Xylanases produced by Aspergillus niger are industrially important and many types of xylanases have been reported. Individual xylanases have been well studied for their enzymatic properties, gene cloning, and heterologous expression. However, less attention has been paid to the relationship between xylanase genes carried on the A. niger genome and xylanases produced by A. niger strains. Therefore, we examined xylanase genes encoded on the genome of A. niger E-1 and xylanases produced in culture. Seven putative xylanase genes, xynI-VII (named in ascending order of the molecular masses of the deduced amino acid sequences), were amplified from the strain E-1 genome using primers designed from the genome sequence of A. niger CBS 513.88 by PCR and phylogenetically classified into three clusters. Additionally, culture supernatant analysis by DE52 anion-exchange column chromatography revealed that this strain produced three xylanases, XynII, XynIII, and XynVII, which were identified by N-terminal amino acid sequencing and MALDI-TOF-MS analyses, in culture when gown in 0.5% xylan medium supplemented with 50 mM succinate. Furthermore, XynVII, the only GH family 10 xylanase in A. niger E-1, was purified and characterized. The purified enzyme showed a single band with a molecular mass of 35 kDa by SDS-PAGE. The highest activity of purified XynVII was observed at 55°C and pH 5.5. The enzyme was stable in the broad pH range of 3-10 and up to 60°C and was resistant to most metal ions and modifying regents. XynVII showed high specificity against beechwood xylan with K m and V max values of 2.8 mg mL(-1) and 127 μmol min(-1)mg(-1), respectively. TLC and MALDI-TOF-MS analyses showed that the final hydrolyzed products of the enzyme from beechwood xylan were xylose, xylobiose, and xylotriose substituted with a 4-o-metylglucuronic acid residue.

Yeast identification in floral nectar of Mimulus aurantiacus (Invited)

Science.gov (United States)

Kyauk, C.; Belisle, M.; Fukami, T.

2009-12-01

Nectar is such a sugar-rich resource that serves as a natural habitat in which microbes thrive. As a result, yeasts arrive to nectar on the bodies of pollinators such as hummingbirds and bees. Yeasts use the sugar in nectar for their own needs when introduced. This research focuses on the identification of different types of yeast that are found in the nectar of Mimulus aurantiacus (commonly known as sticky monkey-flower). Unopened Mimulus aurantiacus flower buds were tagged at Jasper Ridge and bagged three days later. Floral nectar was then extracted and plated on potato dextrose agar. Colonies on the plates were isolated and DNA was extracted from each sample using QIAGEN DNeasy Plant Mini Kit. The DNA was amplified through PCR and ran through gel electrophoresis. The PCR product was used to clone the nectar samples into an E.coli vector. Finally, a phylogenetic tree was created by BLAST searching sequences in GenBank using the Internal Transcribed Space (ITS) locus. It was found that 18 of the 50 identified species were Candida magnifica, 14 was Candida rancensis, 6 were Crytococcus albidus and there were 3 or less of the following: Starmella bombicola, Candida floricola, Aureobasidium pullulans, Pichia kluyvera, Metschnikowa cibodaserisis, Rhodotorua colostri, and Malassezia globosa. The low diversity of the yeast could have been due to several factors: time of collection, demographics of Jasper Ridge, low variety of pollinators, and sugar concentration of the nectar. The results of this study serve as a necessary first step for a recently started research project on ecological interactions between plants, pollinators, and nectar-living yeast. More generally, this research studies the use of the nectar-living yeast community as a natural microcosm for addressing basic questions about the role of dispersal and competitive and facilitative interactions in ecological succession.

Comparison of kinetic characteristics of xylanases from Aspergillus ...

African Journals Online (AJOL)

LAB

2013-05-08

May 8, 2013 ... convert the substrate into products. The xylanase from A. ... be evidence that this enzyme is less active than the xylanase from A. niger. Moreover, the ..... lignocellulosic biomass structural polysaccharides. Biotechnol. Agron.

Purification and characterization of xylanase from Aspergillus ...

African Journals Online (AJOL)

MIET

2013-05-15

May 15, 2013 ... processing (Collins et al., 2005). Frequent ... xylanases (Stricker et al., 2008). The use of cheaper lignocellulosic residues viz. wheat bran, wheat straw, corn cob and sugarcane bagasse can be used as growth ..... Table 3. Effect of different temperature on xylanase activity from A. fumigatus (enzyme reaction.

Degradation of natural cellulose by thermophilic and thermotolerant fungi

Energy Technology Data Exchange (ETDEWEB)

Thakre, A P; Johri, B N

1981-06-01

Aspergillus fumigatus Friesen, Sporotrichum sp., Thermoascus aurantiacus Miche and Torula thermophila Cooney and Emerson were able to degrade filter paper to an appreciable extent. Absidia corymbifera (Cohn) Saccardo et Trotter, Rhizopus microsporus van Tieghem and R. rhizopodiformis (Cohn) Zopf could not degrade filter paper though they were able to grow on the media supplied. The fungi able to degrade filter paper were also capable of elaborating extracellular cellulase and produced sufficient hydrolysis of carboxymethyl cellulose. The Cx enzyme was stable at 45 degrees C for 25 days. An incubation period of 15 to 25 days was sufficient not only to degrade CMC but even more complex substrates, such as jute, cotton and filter paper. The cellulases of these fungi were inductive in nature. (Refs. 11).

Thermophilic and alkalophilic xylanases from several Dictyoglomus isolates

Energy Technology Data Exchange (ETDEWEB)

Mathrani, I M; Ahring, B K [Technical Univ. of Denmark, Lyngby (Denmark). Anaerobic Microbiology/Biotechnology Group

1992-10-01

Supernatant xylanases from three thermophilic and strictly anaerobic Dictyoglomus strains isolated from very different environments were examined: The type species, D. thermophilum[sup T], from a hot-spring in Japan; strain B1, a recently described strictly xylanutilizing Dictyoglomus from a paper-pulp factory in Finland; and strain B4a, isolated from a thermal pool on Iceland. The highest enzymatic activity observed from batch-culture supernatant with 4 g l[sup -1] of beech xylan as growth substrate was 3.8x10[sup -6] kat l[sup -1]. The K[sub m] for the xylanases of strain B1 was 4.7 g beech xylan l[sup -1]. The xylanases of all the isolates had a broad range of activity with respect to pH, showing good activity from pH 5.5 to near 9.0. The xylanases from the three isolates had a very high temperature optimum of 80deg C, maximum temperature for extended activity between 80 and 90deg C, and a thermal half-life of over 1 h at 90deg C for strain B1. The application of thermophilic alkalophilic xylanases to paper pulping was discussed. (orig.).

Purification and Characterization of Streptomyces sp. SKK1-8 xylanase

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Nunuk Widhyastuti

2008-11-01

Full Text Available Streptomyces sp. SKK1-8 is a xylanase produced bacteria. Purified xylanase has an optimum condition at pH 4.5 and 50oC. The molecular mass of purified xylanase were determined to be 14.4 kDa and 13.4 kDa. The xylanase was capable of hydrolysing p-NP-α-L-arabinofuranoside, p-NP-β-D-xylanopiranoside, p-NP-β-D-glucopiranoside, p-NP-α-D-galactopiranoside. The Km and Vmax values at 50oC measured on Birchwood xylan were 0.101 mg/ml and 0.1796 μmoles/minute/ml.

Cloning and expression of chaetomium thermophilum xylanase 11-A

International Nuclear Information System (INIS)

Andleeb, S.; Latif, F.; Afzal, S.; Mukhtar, Z.; Mansoor, S.; Rajoka, I.

2008-01-01

The various thermophilic fungi like Chaetomium thermophile has potential to secrete xylanase and cellulase enzymes. In the present study eukaryotic expression system of Pichia pastoris (yeast) was used to express xylanase gene. The xylanase (Xyn 11-A) gene was isolated from C. thermophile strain NIBGE-1. Primers were designed to amplify the gene, ligated into P. pastoris pPIC3.5K vector, the resultant recombinant clone pSSZ810 was transformed into the genome of P. pastoris GS115 strain through electroporation. Transformants were selected on yeast peptone dextrose medium (YPD) plates containing antibiotic geneticin (100 mg/ml) upto final concentration of 0.75 mg/ml. The maximum activity of xylanase 2.04 U/ml after incubation of 2 hours at 50 degree C was observed in the presence of 100% methanol inducer upto final concentration of 30 macro L (0.5%) as compared to control. HPLC analysis represented high peak of xylose as compared to control. SDS-PAGE indicated approx. 28 kDa protein of expressed xylanase gene. (author)

Extractive fermentation of xylanase from Aspergillus tamarii URM 4634 in a bioreactor.

Science.gov (United States)

da Silva, Anna Carolina; Soares de França Queiroz, Alana Emília; Evaristo dos Santos Nascimento, Talita Camila; Rodrigues, Cristine; Gomes, José Erick Galindo; Souza-Motta, Cristina Maria; Porto de Souza Vandenberghe, Luciana; Valente de Medeiros, Erika; Moreira, Keila Aparecida; Herculano, Polyanna Nunes

2014-08-01

Of the many reported applications for xylanase, its use as a food supplement has played an important role for monogastric animals, because it can improve the utilisation of nutrients. The aim of this work was to produce xylanase by extractive fermentation in an aqueous two-phase system using Aspergillus tamarii URM 4634, increasing the scale of production in a bioreactor, partially characterising the xylanase and evaluating its influence on monogastric digestion in vitro. Through extractive fermentation in a bioreactor, xylanase was obtained with an activity of 331.4 U mL(-1) and 72% yield. The xylanase was stable under variable pH and temperature conditions, and it was optimally active at pH 3.6 and 90 °C. Xylanase activity potentiated the simulation of complete monogastric digestion by 6%, and only Mg2+ inhibited its activity. This process provides a system for efficient xylanase production by A. tamarii URM 4634 that has great potential for industrial use.

Screening and production study of microbial xylanase producers from Brazilian Cerrado.

Science.gov (United States)

Alves-Prado, Heloiza Ferreira; Pavezzi, Fabiana Carina; Leite, Rodrigo Simões Ribeiro; de Oliveira, Valéria Maia; Sette, Lara Durães; Dasilva, Roberto

2010-05-01

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 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, wheat bran, corn straw, corncob, and sugar cane bagasse. Corn straw and wheat bran show a good xylanase activity after 72 h of fermentation. A fungus identified as N. spinosa (strain P2D16) was cultivated on solid-state fermentation using as substrate source wheat bran, wheat bran plus sawdust, corn straw, corncob, cassava bran, and sugar cane bagasse. Wheat bran and corncobs show the better xylanase production after 72 h of fermentation. Both crude xylanases were characterized and a bacterial xylanase shows optimum pH for enzyme activity at 6.0, whereas a fungal xylanase has optimum pH at 5.0-5.5. They were

Xylanases of marine fungi of potential use for biobleaching of paper pulp

Digital Repository Service at National Institute of Oceanography (India)

Raghukumar, C.; Muraleedharan, U.; Gaud, V.R.; Mishra, R.

isolates obtained from marine habitat showed alkaline xylanase activity. The crude enzyme from NIOCC isolate # 3 (Aspergillus niger) with high xylanase activity, cellulase-free and unique properties containing 580 U L-1 of xylanase, could bring about...

Improvement of Xylanase Production by Cochliobolus sativus in Submerged Culture

Directory of Open Access Journals (Sweden)

Yasser Bakri

2008-01-01

Full Text Available The xylanase production by a new Cochliobolus sativus Cs5 strain was improved under submerged fermentation. The xylanase was induced by xylan and repressed by glucose, sucrose, maltose, xylose, starch and cellulose. Highest enzyme production (98.25 IU/mL was recorded when wheat straw (4 % by mass per volume was used as a carbon source after 120 h of incubation. NaNO3 increased xylanase production 5.4-fold as compared to the control. Optimum initial pH was found to be 4.5 to 5. The C. sativus Cs5 strain grown under submerged culture in a simple medium proved to be a promising microorganism for xylanase production.

Xylanase production by a newly isolated Aspergillus niger SS7 in submerged culture.

Science.gov (United States)

Bakri, Yasser; Al-Jazairi, Manal; Al-Kayat, Ghassan

2008-01-01

Xylanase production by a newly isolated Aspergillus niger SS7 was studied in submerged culture. The optimum initial pH for xylanase production was found to be 7.0. Different agricultural and industrial wastes were evaluated for their ability to induce xylanase production by this isolate. The best xylanase production (293.82 IU/ml) was recorded at 3% (w/v) corn cob hulls after 120 h of incubation. The Aspergillus niger SS7 isolate grown in a simple medium, proved to be a promising microorganism for xylanase production.

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

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Punniavan Sakthiselvan

2014-12-01

Full Text Available 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.

Biotechnology of microbial xylanases: enzymology, molecular biology, and application.

Science.gov (United States)

Subramaniyan, S; Prema, P

2002-01-01

Xylanases are hydrolases depolymerizing the plant cell wall component xylan, the second most abundant polysaccharide. The molecular structure and hydrolytic pattern of xylanases have been reported extensively and the mechanism of hydrolysis has also been proposed. There are several models for the gene regulation of which this article could add to the wealth of knowledge. Future work on the application of these enzymes in the paper and pulp, food industry, in environmental science, that is, bio-fueling, effluent treatment, and agro-waste treatment, etc. require a complete understanding of the functional and genetic significance of the xylanases. However, the thrust area has been identified as the paper and pulp industry. The major problem in the field of paper bleaching is the removal of lignin and its derivatives, which are linked to cellulose and xylan. Xylanases are more suitable in the paper and pulp industry than lignin-degrading systems.

Efficiency of new fungal cellulase systems in boosting enzymatic degradation of barley straw lignocellulose

DEFF Research Database (Denmark)

Rosgaard, L.; Pedersen, S.; Meyer, Anne Boye Strunge

2006-01-01

This study examined the cellulytic effects on steam-pretreated barley straw of cellulose-degrading enzyme systems from the five thermophilic fungi Chaetomium thermophilum, Thielavia terrestris, Thermoascus aurantiacus, Corynascus thermophilus, and Myceliophthora thermophila and from the mesophile...... Penicillum funiculosum. The catalytic glucose release was compared after treatments with each of the crude enzyme systems when added to a benchmark blend of a commercial cellulase product, Celluclast, derived from Trichoderma reesei and a P-glucosidase, Novozym 188, from Aspergillus niger. The enzymatic...... treatments were evaluated in an experimental design template comprising a span of pH (3.5-6.5) and temperature (35-65 degrees C) reaction combinations. The addition to Celluclast + Novozym 188 of low dosages of the crude enzyme systems, corresponding to 10 wt % of the total enzyme protein load, increased...

Production of xylanases by an Aspergillus niger strain in wastes grain

Directory of Open Access Journals (Sweden)

Simone Cristine Izidoro

2014-08-01

Full Text Available Many fungi are used in order to extract products from their metabolism through bioprocesses capable of minimizing adverse effects caused by agro-industrial wastes in the environment. The aim of this study was to evaluate the xylanase production by an Aspergillus niger strain, using agro-industrial wastes as substrate. Brewer’s spent grain was the best inducer of xylanase activity. Higher levels of xylanase were obtained when the fungus was grown in liquid Vogel medium, pH 5.0, at 30ºC, during 5 days. The temperature for optimum activity was 50ºC and optimum pH 5.0. The enzyme was stable at 50ºC, with a half-life of 240 min. High pH stability was verified from pH 4.5 to 7.0. These characteristics exhibited by A. niger xylanase turn this enzyme attractive for some industrial applications, such as in feed and food industries. Additionally, the use of brewer’s spent grain, an abundantly available and low-cost residue, as substrate for xylanase production can not only add value and decrease the amount of this waste, but also reduce xylanase production cost.

Thermo-mechanical and micro-structural properties of xylanase containing whole wheat bread

Directory of Open Access Journals (Sweden)

G. Ghoshal

2016-12-01

Full Text Available Xylanase is a hemicellulase that can hydrolyses the complex polysaccharides. Hemicelluloses are main components of cell walls of cereal grains. Moreover, hemicelluloses are considered as potential sources of mono- and oligosaccharides. In this study, influence of xylanase on the physicochemical properties and sensory qualities of the whole wheat bread during storage was investigated. Studies of whole wheat bread on microstructure, texture, thermotics, Scanning Electron Microscopic (SEM, X-Ray Diffraction (XRD were conducted at ambient temperature of 25 and 4 °C respectively. During storage at different temperatures, bread containing xylanase exhibited less firmness but larger volume with whiter crumb color and longer shelf life as compared to control bread. Results of firmness, enthalpy, Fourier Transformation Infra Red (FTIR and X-Ray Diffraction (XRD studies suggested a lower staling rate of bread containing xylanase as compared to control one. Bread containing xylanase showed a smoother surface and more uniform pore size than the control. Significant differences in microstructure of control and bread containing xylanase were observed which might be attributed due to the change in water starch gluten interaction. These differences were also found to be interrelated to the textural properties of bread. Better sensory features were achieved in bread containing xylanase.

Effect of corn cobs concentration on xylanase biosynthesis by ...

African Journals Online (AJOL)

Corn cobs, an indigenous carbon source, were tested as substrate by Aspergillus niger for optimum synthesis of xylanase using the submerged fermentation technique. The trials for xylanase production were conducted at three concentration levels (2.5, 3.0 and 3.5%) of corn cobs, four different fermentation temperatures ...

Production of cellulase-free xylanase by Aspergillus flavus: Effect of ...

African Journals Online (AJOL)

Nelciele

Aspergillus flavus produced high levels of xylanase on agricultural residues with ... addition of 5% glycerol, mannitol or xylitol protected the xylanase from thermal inactivation at 50°C. The .... most often included in nutrient media for microbial.

Synergistic effect of cellulase and xylanase during hydrolysis of natural lignocellulosic substrates.

Science.gov (United States)

Song, Hui-Ting; Gao, Yuan; Yang, Yi-Min; Xiao, Wen-Jing; Liu, Shi-Hui; Xia, Wu-Cheng; Liu, Zi-Lu; Yi, Li; Jiang, Zheng-Bing

2016-11-01

Synergistic combination of cellulase and xylanase has been performed on pre-treated substrates in many previous studies, while few on natural substrates. In this study, three unpretreated lignocellulosic substrates were studied, including corncob, corn stover, and rice straw. The results indicated that when the mixed cellulase and xylanase were applied, reducing sugar concentrations were calculated as 19.53, 15.56, and 17.35mg/ml, respectively, based on the 3,5 dinitrosalicylic acid (DNS) method. Compared to the treatment with only cellulose, the hydrolysis yields caused by mixed cellulase and xylanase were improved by 133%, 164%, and 545%, respectively. In addition, the conversion yield of corncob, corn stover, and rice straw by cellulase-xylanase co-treatment reached 43.9%, 48.5%, and 40.2%, respectively, based on HPLC analysis, which confirmed the synergistic effect of cellulase-xylanase that was much higher than either of the single enzyme treatment. The substrate morphology was also evaluated to explore the synergistic mechanism of cellulase-xylanase. Copyright © 2016 Elsevier Ltd. All rights reserved.

Das Höhlenlangbein Amilenus aurantiacus (Opiliones: Phalangiidae ist Höhlentier des Jahres 2016 in Deutschland

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Zaenker, Stefan

2016-09-01

Full Text Available With the nomination of the ‘Cave Animal of the Year’ the Society of German Cave and Karst Explorers calls public and authorities’ attention to the understudied biodiversity of subterranean ecosystems. Here the Cave Animal of the Year 2016, Amilenus aurantiacus (Simon, 1881, is presented. It is the first time that a harvestman has been chosen. Ist ecology, habitat and morphology are described. New records from Hesse, Bavaria, Baden-Württemberg and North Rhine-Westphalia are listed and discussed.

The Purification and Characterization of Superoxide Dismutase from Chloroflexus aurantiacus and the Effects of UV Radiation on the Activity of SOD and Catalase in Hydrothermal Mats of Yellowstone National Park

Science.gov (United States)

Lancaster, Vanessa; Blankenship, Robert E.; Rothschild, Lynn

2001-01-01

Chloroflexus aurantiacus is a thermotolerant anoxygenic green phototrophic bacterium that is prominent in alkaline hot springs at temperatures between 52 and 60 C. This species often grows in the hyperoxic environment beneath cyanobacterial mats at higher temperatures up to 70 - 72 C. Cf. aurantiacus is an evolutionarily important organism since it is in the earliest branch of the eubacteria that are capable of photosynthesis and many of its characteristics can be found in other diverse groups of phototrophic bacteria. Additional information is contained in the original extended abstract.

Statistical optimization of activity and stability of β-xylanase ...

African Journals Online (AJOL)

STORAGESEVER

2008-10-20

Oct 20, 2008 ... A factorial design was performed to find the best conditions of pH and temperature for β-xylanase activity and to maintain its activity for prolonged periods of time of pure xylanase produced by newly isolated Thermomyces lanuginosus THKU-49. The central composite design (CCD) used for the analysis of ...

Exogenous quinones inhibit photosynthetic electron transfer in Chloroflexus aurantiacus by specific quenching of the excited bacteriochlorophyll c antenna

DEFF Research Database (Denmark)

Frigaard, N-U; Tokita, S; Matsuura, K

1999-01-01

In the photosynthetic green filamentous bacterium Chloroflexus aurantiacus, excitation energy is transferred from a large bacteriochlorophyll (BChl) c antenna via smaller BChl a antennas to the reaction center. The effects of substituted 1,4-naphthoquinones on BChl c and BChl a fluorescence and o...... antenna. Our results provide a model system for studying the redox-dependent antenna quenching in green sulfur bacteria because the antennas in these bacteria inherently exhibit a sensitivity to O(2) similar to the quinone-supplemented cells of Cfx. aurantiacus....... and on flash-induced cytochrome c oxidation were studied in whole cells under aerobic conditions. BChl c fluorescence in a cell suspension with 5.4 microM BChl c was quenched to 50% by addition of 0.6 microM shikonin ((R)-2-(1-hydroxy-4-methyl-3-pentenyl)-5,8-dihydroxy-1, 4-naphthoquinone), 0.9 microM 5......-hydroxy-1,4-naphthoquinone, or 4 microM 2-acetyl-3-methyl-1,4-naphthoquinone. Between 25 and 100 times higher quinone concentrations were needed to quench BChl a fluorescence to a similar extent. These quinones also efficiently inhibited flash-induced cytochrome c oxidation when BChl c was excited...

Cloning and expression of chaetomium thermophilum xylanase 11-A gene in prokaryote

International Nuclear Information System (INIS)

Wajid, S.; Latif, F.; Afzal, S.; Rajoka, I.

2008-01-01

The xylanase gene was cloned into pET32a(+) and expressed in E. coli BL21 under T7 promotor alongwith fusion protein. The SDS-PAGE and western blot analysis showed a protein of 42 kDa. The best expression of xylanase enzyme was found by using xylose as carbon source and lactose as an inducer. The maximum activity of xylanase expressed in E. coli was 6.02 U/mL in the presence of 2% xylose in DS medium. The activity of recombinant xylanase was observed on 1% xylan LB agar plates, showed halos of xylan clearance when lactose was used as an inducer. (author)

Xylanase XYN IV from Trichoderma reesei showing exo- and endo-xylanase activity

Science.gov (United States)

A novel xylanase from Trichoderma reesei Rut C30, named XYN IV, was purified from the cellulolytic system of the fungus. The enzyme was discovered on its ability to attack aldotetraohexenuronic acid (HexA-2Xyl-4Xyl-4Xyl, HexA3Xyl3), releasing the reducing-end xylose residue. XYN IV exhibited catalyt...

A xylanase-aided enzymatic pretreatment facilitates cellulose nanofibrillation.

Science.gov (United States)

Long, Lingfeng; Tian, Dong; Hu, Jinguang; Wang, Fei; Saddler, Jack

2017-11-01

Although biological pretreatment of cellulosic fiber based on endoglucanases has shown some promise to facilitate cellulose nanofibrillation, its efficacy is still limited. In this study, a xylanase-aided endoglucanase pretreatment was assessed on the bleached hardwood and softwood Kraft pulps to facilitate the downstream cellulose nanofibrillation. Four commercial xylanase preparations were compared and the changes of major fiber physicochemical characteristics such as cellulose/hemicellulose content, gross fiber properties, fiber morphologies, cellulose accessibility/degree of polymerization (DP)/crystallinity were systematically evaluated before and after enzymatic pretreatment. It showed that the synergistic cooperation between endoglucanase and certain xylanase (Biobrite) could efficiently "open up" the hardwood Kraft pulp with limited carbohydrates degradation (cellulose nanofibrillation during mild sonication process (90Wh) with more uniform disintegrated nanofibril products (50-150nm, as assessed by scanning electron microscopy and UV-vis spectroscopy). Copyright © 2017 Elsevier Ltd. All rights reserved.

Highly thermostable xylanase production from a thermophilic Geobacillus sp. strain WSUCF1 utilizing lignocellulosic biomass

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Aditya eBhalla

2015-06-01

Full Text Available AbstractEfficient enzymatic hydrolysis of lignocellulose to fermentable sugars requires a complete repertoire of biomass deconstruction enzymes. Hemicellulases play an important role in hydrolyzing hemicellulose component of lignocellulose to xylo-oligosaccharides and xylose. Thermostable xylanases have been a focus of attention as industrially important enzymes due to their long shelf life at high temperatures. Geobacillus sp. strain WSUCF1 produced thermostable xylanase activity (crude xylanase cocktail when grown on xylan or various inexpensive untreated and pretreated lignocellulosic biomasses such as prairie cord grass and corn stover. The optimum pH and temperature for the crude xylanase cocktail were 6.5 and 70ºC, respectively. The WSUCF1 crude xylanase was found to be highly thermostable with half-lives of 18 and 12 days at 60 and 70ºC, respectively. At 70ºC, rates of xylan hydrolysis were also found to be better with the WSUCF1 secretome than those with commercial enzymes, i.e., for WSUCF1 crude xylanase, CellicHTec2, and AccelleraseXY, the percent xylan conversions were 68.9, 49.4, and 28.92, respectively. To the best of our knowledge, WSUCF1 crude xylanase cocktail is among the most thermostable xylanases produced by thermophilic Geobacillus spp. and other thermophilic microbes (optimum growth temperature ≤70ºC. High thermostability, activity over wide range of temperatures, and better xylan hydrolysis than commercial enzymes make WSUCF1 crude xylanase suitable for thermophilic lignocellulose bioconversion processes.

Xylanase-Aided Chlorine Dioxide Bleaching of Bagasse Pulp to Reduce AOX Formation

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Yi Dai

2016-02-01

Full Text Available Xylanase pretreatment was used to improve the chlorine dioxide bleaching of bagasse pulp. The pulp was pretreated with xylanase, which was followed by a chlorine dioxide bleaching stage. The HexA content of the pulp and the AOX content of the bleaching effluent were measured using UV-Vis and GC-MS methods, respectively. The results showed that a good correlation occurred between HexA and kappa number. HexA content of the pulp decreased significantly after the xylanase pretreatment. The AOX content of the bleaching effluent decreased as HexA was removed from the pulp. It was found that AOX could be reduced by up to 29.8%, comparing XD0 with a D0 stage. Fourier transform infrared spectroscopy (FTIR was employed to determine the breakage of chemical bonds in the pulp. It revealed that some lignin and hemicellulose were removed after xylanase treatment. The GC-MS results showed that some toxic chloride such as 2,4,6-trichlorophenol could be completely removed after xylanase pretreatment.

Agro-residues as Alternative for Xylanase Production by Filamentous Fungi

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Adriana Knob

2014-07-01

Full Text Available Agro-industrial wastes are the most abundant renewable resource on earth and are available in large quantities. However, the disposal of these wastes presents an increasing environmental problem. Recently, there has been a great interest in the exploitation of these wastes as low-cost raw materials for the production of value-added compounds as microbial enzymes by submerged or solid-state fermentation systems. This review focuses on alternatives for xylanase production using agro-residues as substrates. In recent years, the interest in xylanase, which plays an important role in the breakdown of xylan, has markedly increased due to its wide variety of biotechnological applications. Among several agro-industrial residues that have been intensively investigated, many, such as wheat bran, wheat straw, and sugarcane bagasse, are suitable and result in high yields of xylanase, leading to low production costs. In addition, many relatively unexplored residues, such as oil palm wastes, sorghum straw, and coffee by-products, are some of the most promising substrates for xylanase production, requiring further assessment.

Production and properties of two types of xylanases from alkalophilic thermophilic Bacillus spp

Energy Technology Data Exchange (ETDEWEB)

Okazaki, W; Akahoshi, R; Akiba, T; Horikoshi, K

1984-05-01

Four strains (W1, W2, W3, and W4) of alkalophilic thermophilic bacteria which produced xylanase were isolated from soils. They were aerobic, spore-forming. Gram-positive, and rod-shaped bacteria and hence identified as the genus Bacillus. The optimal temperatures for growth of the four strains were between 45/sup 0/C and 50/sup 0/C and pH optima were between 9.0 and 10.0. No growth occurred below pH 7.0 or above 55/sup 0/C. The four strains produced xylanases in medium containing xylan or xylose under these conditions. The optimal pH and temperature for activities of the four xylanases ranged from 6.0 to 7.0 and from 65/sup 0/C to 70/sup 0/C, respectively. The four xylanases were stable in the wide pH range from 4.5 to 10.5 at 45/sup 0/C for 1 h. All xylanases split xylan to yield xylose and xylobiose.

Autohydrolysis of plant xylans by apoplastic expression of thermophilic bacterial endo-xylanases

DEFF Research Database (Denmark)

Borkhardt, Bernhard; Harholt, Jesper; Ulvskov, Peter Bjarne

2010-01-01

The genes encoding the two endo-xylanases XynA and XynB from the thermophilic bacterium Dictyoglomus thermophilum were codon optimized for expression in plants. Both xylanases were designed to be constitutively expressed under the control of the CaMV 35S promoter and targeted to the apoplast....... Transient expression in tobacco and stable expression in transgenic Arabidopsis showed that both enzymes were expressed in an active form with temperature optima at 85 °C. Transgenic Arabidopsis accumulating heterologous endo-xylanases appeared phenotypically normal and were fully fertile. The highest...... xylanase activity in Arabidopsis was found in dry stems indicating that the enzymes were not degraded during stem senescence. High levels of enzyme activity were maintained in cell-free extracts from dry transgenic stems during incubation at 85 °C for 24 h. Analysis of cell wall polysaccharides after heat...

The Protective Roles of the Antioxidant Enzymes Superoxide Dismutase and Catalase in the Green Photosynthetic Bacterium Chloroflexus Aurantiacus

Science.gov (United States)

Blankenship, Robert E.; Rothschild, Lynn (Technical Monitor)

2004-01-01

The purpose of this study was to examine the biochemical response of the green thermophilic photosynthetic bacterium Chloroflexus aurantiacus to oxidative stress. Lab experiments focused primarily on characterizing the antioxidant enzyme superoxide dismutase and the response of this organism to oxidative stress. Experiments in the field at the hotsprings in Yellowstone National Park focused on the changes in the level of these enzymes during the day in response to oxidants and to the different types of ultraviolet radiation.

Domain-swapping of mesophilic xylanase with hyper-thermophilic glucanase

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Liu Liangwei

2012-06-01

Full Text Available Abstract Background Domain fusion is limited at enzyme one terminus. The issue was explored by swapping a mesophilic Aspergillus niger GH11 xylanase (Xyn with a hyper-thermophilic Thermotoga maritima glucanase (Glu to construct two chimeras, Xyn-Glu and Glu-Xyn, with an intention to create thermostable xylanase containing glucanase activity. Results When expressed in E. coli BL21(DE3, the two chimeras exhibited bi-functional activities of xylanase and glucanase. The Xyn-Glu Xyn moiety had optimal reaction temperature (Topt at 50 °C and thermal in-activation half-life (t1/2 at 50 °C for 47.6 min, compared to 47 °C and 17.6 min for the Xyn. The Glu-Xyn Xyn moiety had equivalent Topt to and shorter t1/2 (5.2 min than the Xyn. Both chimera Glu moieties were more thermostable than the Glu, and the three enzyme Topt values were higher than 96 °C. The Glu-Xyn Glu moiety optimal pH was 5.8, compared to 3.8 for the Xyn-Glu Glu moiety and the Glu. Both chimera two moieties cooperated with each other in degrading substrates. Conclusions Domain-swapping created different effects on each moiety properties. Fusing the Glu domain at C-terminus increased the xylanase thermostability, but fusing the Glu domain at N-terminus decreased the xylanase thermostability. Fusing the Xyn domain at either terminus increased the glucanase thermostability, and fusing the Xyn domain at C-terminus shifted the glucanase pH property 2 units higher towards alkaline environments. Fusing a domain at C-terminus contributes more to enzyme catalytic activity; whereas, fusing a bigger domain at N-terminus disturbs enzyme substrate binding affinity.

High genetic diversity and different distributions of glycosyl hydrolase family 10 and 11 xylanases in the goat rumen.

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Guozeng Wang

Full Text Available BACKGROUND: The rumen harbors a complex microbial ecosystem for efficient hydrolysis of plant polysaccharides which are the main constituent of the diet. Xylanase is crucial for hemicellulose hydrolysis and plays an important role in the plant cell wall degradation. Xylanases of ruminal strains were widely studied, but few studies have focused on their diversity in rumen microenvironment. METHODOLOGY/PRINCIPAL FINDINGS: We explored the genetic diversity of xylanases belonging to two major glycosyl hydrolase families (GH 10 and 11 in goat rumen contents by analyzing the amplicons generated with two degenerate primer sets. Fifty-two distinct GH 10 and 35 GH 11 xylanase gene fragments (similarity <95% were retrieved, and most had low identities with known sequences. Based on phylogenetic analysis, all GH 10 xylanase sequences fell into seven clusters, and 88.5% of them were related to xylanases from Bacteroidetes. Five clusters of GH 11 xylanase sequences were identified. Of these, 85.7% were related to xylanases from Firmicutes, and 14.3% were related to those of rumen fungi. Two full-length xylanase genes (one for each family were directly cloned and expressed in Escherichia coli. Both the recombinant enzymes showed substantial xylanase activity, and were purified and characterized. Combined with the results of sheep rumen, Bacteroidetes and Firmicutes are the two major phyla of xylan-degrading microorganisms in rumen, which is distinct from the representatives of other environments such as soil and termite hindgut, suggesting that xylan-degrading microorganisms are environment specific. CONCLUSION/SIGNIFICANCE: The numerous new xylanase genes suggested the functional diversity of xylanase in the rumen microenvironment which may have great potential applications in industry and agriculture. The phylogenetic diversity and different distributions of xylanase genes will help us understand their roles in plant cell wall degradation in the rumen

Production of beta-xylanase and beta-xylosidase by the extremely halophilic archaeon Halorhabdus utahensis

DEFF Research Database (Denmark)

Wainø, M.; Ingvorsen, K.

2003-01-01

-xylosidase stabilities, approximately 55% and 83% of the initial beta-xylanase and beta-xylosidase activities, respectively, remained after 24 h incubation at 20% NaCl. The enzymes were also shown to be slightly thermophilic: P-xylanase activity exhibiting two optima at 55degrees and 70degreesC, while beta......The extremely halophilic archaeon, Halorhabdus utahensis, isolated from the Great Salt Lake, Utah, produced beta-xylanase and beta-xylosidase activities. Both enzymes were active over a broad NaCl range from near zero to 30% NaCl when tested with culture broth. A broad NaCl optimum was observed...... for beta-xylanase activity between 5% and 15% NaCl, while beta-xylosidase activity was highest at 5% NaCl. Almost half of the maximum activities remained at 27%-30% NaCl for both enzyme activities. When dialyzed culture supernatant and culture broth were employed for determination of beta-xylanase and beta...

Cloning, sequencing and expression of a novel xylanase cDNA from ...

African Journals Online (AJOL)

A strain SH 2016, capable of producing xylanase, was isolated and identified as Aspergillus awamori, based on its physiological and biochemical characteristics as well as its ITS rDNA gene sequence analysis. A xylanase gene of 591 bp was cloned from this newly isolated A. awamori and the ORF sequence predicted a ...

Induction and catabolite repression of cellulase and xylanase synthesis in the selected white-rot basidiomycetes

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Aza Kobakhidze

2016-09-01

Full Text Available This paper reports regulation of endoglucanase (EC 3.2.1.4 and xylanase (EC 3.2.1.8 production in submerged cultivation of four white-rot basidiomycetes. Among carbon sources tested, the Avicel-based medium provided the highest levels of both hydrolases activities in all fungal cultures. However, the maximum endoglucanase and xylanase activities of the tested basidiomycetes varied from 3.9 U/ml and 7.4 U/ml in Fomes fomentarius to 34.2 U/ml and 29.5 U/ml in Pseudotrametes gibbosa, respectively (P. gibbosa specific cellulase and xylanase activities achieved 8.55 and 7.38 U/mg, respectively. Replacement of Avicel in the medium with carboxymethyl cellulose or xylan significantly lowered the enzyme yield of the tested fungi. Moreover, xylan did not ensure high xylanase activity of these fungi. Lignocellulosic substrates used as a carbon source provided poorer productivity (the specific CMCase activity was 1.12–3.62 U/mg and the specific xylanase activity was 1.95–3.32 U/mg. Expression of endoglucanase and xylanase synthesis in Panus lecometei and P. gibbosa was inducible; supplementation of the glycerol-containing medium with Avicel accompanied with a sharp increase of the fungal specific CMCase and xylanase activities from 0.02–0.04 U/mg to 1.30–8.55 U/mg. Supplementation of the Avicel-induced cultures with glucose or glycerol caused a catabolite repression of the cellulase and xylanase formation by P. gibbosa and P. lecometei. The enzyme synthesis resumed only after depletion of easily metabolizable carbon source, glucose or glycerol, from the medium. The data received suggest that in the tested fungi endoglucanase and xylanase synthesis is under control by a common regulatory mechanism.

A novel cellulase free alkaliphilic xylanase from alkali tolerant Penicillium citrinum: production, purification and characterization.

Science.gov (United States)

Dutta, T; Sengupta, R; Sahoo, R; Sinha Ray, S; Bhattacharjee, A; Ghosh, S

2007-02-01

The enzymatic hydrolysis of xylan has potential economic and environment-friendly applications. Therefore, attention is focused here on the discovery of new extremophilic xylanase in order to meet the requirements of industry. An extracellular xylanase was purified from the culture filtrate of P. citrinum grown on wheat bran bed in solid substrate fermentation. Single step purification was achieved using hydrophobic interaction chromatography. The purified enzyme showed a single band on SDS-PAGE with an apparent molecular weight of c. 25 kDa and pI of 3.6. Stimulation of the activity by beta mercaptoethanol, dithiotheritol (DTT) and cysteine was observed. Moderately thermostable xylanase showed optimum activity at 50 degrees C at pH 8.5. Xylanase purified from P. citrinum was alkaliphilic and moderately thermostable in nature. The present work reports for the first time the purification and characterization of a novel endoglucanase free alkaliphilic xylanase from the alkali tolerant fungus Penicillium citrinum. The alkaliphilicity and moderate thermostability of this xylanase may have potential implications in paper and pulp industries.

Benefits from additives and xylanase during enzymatic hydrolysis of bamboo shoot and mature bamboo.

Science.gov (United States)

Li, Kena; Wang, Xiao; Wang, Jingfeng; Zhang, Junhua

2015-09-01

Effects of additives (BSA, PEG 6000, and Tween 80) on enzymatic hydrolysis of bamboo shoot and mature bamboo fractions (bamboo green, bamboo timber, bamboo yellow, bamboo node, and bamboo branches) by cellulases and/or xylanase were evaluated. The addition of additives was comparable to the increase of cellulase loadings in the conversion of cellulose and xylan in bamboo fractions. Supplementation of xylanase (1 mg/g DM) with cellulases (10 FPU/g DM) in the hydrolysis of bamboo fractions was more efficient than addition of additives in the production of glucose and xylose. Moreover, addition of additives could further increase the glucose release from different bamboo fractions by cellulases and xylanase. Bamboo green exhibited the lowest hydrolyzability. Almost all of the polysaccharides in pretreated bamboo shoot fractions were hydrolyzed by cellulases with the addition of additives or xylanase. Additives and xylanase showed great potential for reducing cellulase requirement in the hydrolysis of bamboo. Copyright © 2015 Elsevier Ltd. All rights reserved.

A multipurpose immobilized biocatalyst with pectinase, xylanase and cellulase activities

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Gupta Munishwar

2007-06-01

Full Text Available Abstract Background The use of immobilized enzymes for catalyzing various biotransformations is now a widely used approach. In recent years, cross-linked enzyme aggregates (CLEAs have emerged as a novel and versatile biocatalyst design. The present work deals with the preparation of a CLEA from a commercial preparation, Pectinex™ Ultra SP-L, which contains pectinase, xylanase and cellulase activities. The CLEA obtained could be used for any of the enzyme activities. The CLEA was characterized in terms of kinetic parameters, thermal stability and reusability in the context of all the three enzyme activities. Results Complete precipitation of the three enzyme activities was obtained with n-propanol. When resulting precipitates were subjected to cross-linking with 5 mM glutaraldehyde, the three activities initially present (pectinase, xylanase and cellulase were completely retained after cross-linking. The Vmax/Km values were increased from 11, 75 and 16 to 14, 80 and 19 in case of pectinase, xylanase and cellulase activities respectively. The thermal stability was studied at 50°C, 60°C and 70°C for pectinase, xylanase and cellulase respectively. Half-lives were improved from 17, 22 and 32 minutes to 180, 82 and 91 minutes for pectinase, xylanase and cellulase respectively. All three of the enzymes in CLEA could be reused three times without any loss of activity. Conclusion A single multipurpose biocatalyst has been designed which can be used for carrying out three different and independent reactions; 1 hydrolysis of pectin, 2 hydrolysis of xylan and 3 hydrolysis of cellulose. The preparation is more stable at higher temperatures as compared to the free enzymes.

Production of xylanases and cellulases by aspergillus fumigatus ms16 using crude lignocellulosic substrates

International Nuclear Information System (INIS)

Naseeb, S.; Sohai, M.; Ahmad, A.; Khan, S.A.

2015-01-01

Xylanolytic and cellulolytic potential of a soil isolate, Aspergillus fumigatus (MS16) was studied by growing it on a variety of lignocellulosics, purified cellulose and xylan supplemented media. It was noted that carboxymethyl cellulose, salicin and xylan induce the -glucosidase and xylanase, respectively production of endoglucanase. The study revealed that Aspergillus fumigatus (MS16) co-secretes xylanase and cellulase in the presence of xylan; the ratio of the two enzymes was influenced by the initial pH of the medium. The maximum titers of xylanase and cellulase were noted at initial pH of 5.0. Relatively higher titers of both the enzymes were obtained when the fungus was cultivated at 35 degree C. Whereas, cellulase production was not detected when the fungus was cultivated at 40 degree C. The volumetric productivity (Qp) of xylanase was much higher than cellulases. The organism produced 2-3 folds higher titers of xylanase when grown on lignocellulosic materials in submerged cultivation than under solid-state cultivation, suggesting a different pattern of enzyme production in presence and in absence of free water. The partial characterization of enzymes showed that xylanase from this organism has -glucosidase. The higher melting temperature than endoglucanase and optimum temperature for activity was higher for xylanases than cellulases, whereas the optimum pH differed slightly i.e. in the range of 4.0-5.0. Enzyme preparation from this organism was loaded on some crude substrates and it showed that the enzyme preparation can be used to hydrolyze a variety of vegetable and agricultural waste materials. (author)

The Use of Xylanases from Different Microbial Origin in Bread Baking and Their Effects on Bread Qualities

Science.gov (United States)

Al-Widyan, Omar; Khataibeh, Moayad H.; Abu-Alruz, Khaled

Effects of xylanases on bread quality were examined. Enzymes used were endo-xylanase (EC 3.2.1.8) from different sources of microorganisms. Baked loaves were assessed for Loaves volume, colour and staling rate. Xylanases produced from rumen microorganisms M6 had clearly positive effects on loaf volume of bread as well as anti-firming potential. M3 (produced from Trichoderma longibrachiatum) improved crumb softness. The use of xylanase for breadmaking lowered firmness of bread crumb effectively compared with control loaf. It can be summarized that xylanases had significant positive effects on bread characteristics. In particular, they had advantage in retarding the staling rate of bread. It is recommended that the optimum dosage of enzymes, method of application in industrial scale especially with xylanase should be studied further in order to gain the great advantages of enzyme addition in breadmaking.

Improvement of xylanase production by a parasexual cross between Aspergillus niger strains

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Octavio Loera

2003-03-01

Full Text Available A diploid strain (D4 isolated via parasexual recombination between two Aspergillus niger xylanase overproducing mutants was characterised in terms of enzyme production and catabolite repression by glucose. This strain increased xylanase production (607 nkat/ml, which was nearly 100% higher than titers achieved by the wild type strain (305 nkat/ml and 28% higher than the best mutant used to induce parasexual cycle. Diploid D4 was also less sensitive to carbon catabolite repression by glucose, since xylanolytic activity was detected under conditions normally repressing production by the wild type strain. No decrease in maximal xylanase levels was observed in the presence of glucose for diploid D4.Um cepa diplóide (D4 isolada por combinação parasexual entre dois Aspergillus niger, mutantes superprodutores de xylanase foi caracterizado através da produção de (607 nkat/ml e repressão catabólica por glicose. Essa cepa aumenta a produção de xylanase em mais de 100% em comparação com uma cepa selvagem (305 nkat/ml e 28% superior do que o melhor mutante usado para induzir o ciclo parasexual. A cepa diplóide D4 foi também menos sensível a repressão catabólica pela glicose, sendo que a atividade xylanolitica foi detectada sob condições normalmente de produção repressiva pela cepa selvagem. Não foi observado um decréscimo na produção máxima de xylanase em presença de glicose para o diplóide D4.

Purification and Characterization of Haloalkaline, Organic Solvent Stable Xylanase from Newly Isolated Halophilic Bacterium-OKH

Science.gov (United States)

Sanghvi, Gaurav; Jivrajani, Mehul; Patel, Nirav; Jivrajani, Heta; Bhaskara, Govinal Badiger; Patel, Shivani

2014-01-01

A novel, alkali-tolerant halophilic bacterium-OKH with an ability to produce extracellular halophilic, alkali-tolerant, organic solvent stable, and moderately thermostable xylanase was isolated from salt salterns of Mithapur region, Gujarat, India. Identification of the bacterium was done based upon biochemical tests and 16S rRNA sequence. Maximum xylanase production was achieved at pH 9.0 and 37°C temperature in the medium containing 15% NaCl and 1% (w/v) corn cobs. Sugarcane bagasse and wheat straw also induce xylanase production when used as carbon source. The enzyme was active over a range of 0–25% sodium chloride examined in culture broth. The optimum xylanase activity was observed at 5% sodium chloride. Xylanase was purified with 25.81%-fold purification and 17.1% yield. Kinetic properties such as Km and Vmax were 4.2 mg/mL and 0.31 μmol/min/mL, respectively. The enzyme was stable at pH 6.0 and 50°C with 60% activity after 8 hours of incubation. Enzyme activity was enhanced by Ca2+, Mn2+, and Mg2+ but strongly inhibited by heavy metals such as Hg2+, Fe3+, Ni2+, and Zn2+. Xylanase was found to be stable in organic solvents like glutaraldehyde and isopropanol. The purified enzyme hydrolysed lignocellulosic substrates. Xylanase, purified from the halophilic bacterium-OKH, has potential biotechnological applications. PMID:27350996

Efficient utilization of xylanase and lipase producing thermophilic ...

African Journals Online (AJOL)

Efficient utilization of xylanase and lipase producing thermophilic marine actinomycetes ( Streptomyces albus and Streptomyces hygroscopicus ) in the production of ecofriendly alternative energy from waste.

Cellulase and Xylanase Production from Three Isolates of Indigenous Endophytic Fungi

Science.gov (United States)

Yopi; Tasia, W.; Melliawati, R.

2017-12-01

Cellulases and hemicellulases have good potential to be used in energy production, in pulp, paper, textile industries, as well as in animal feed industries. Moreover, its utilization in food industries also cannot be ignored, among others, cellulase and xylanase roles in bakery, wine, and fruit and vegetables juice production. One of the potential enzyme source is endophytic fungi. Object of this study is to explore the potency of endophytic fungi isolated from medicinal plants as source of cellulolytic and xylanolytic enzymes. HL.47F.216 is endophytic fungi isolated from traditional medicinal plants ironwood tree was determined as xylanase producer. HL.51F.235 from pin-flower tree is cellulase producer, while CBN.6F.29 which produces both xylanase and cellulase is originated from Madagascar periwinkle. HL.47F.216 showed 2.5 cm in clear zone diameter and its xylanase activity was 0.262 U/mL with optimum condition pH 7 at 50°C. HL.51F.235 showed 2.4 cm clear zone diameter and 0.239 U/mL of cellulase activity at pH 5 and 70°C. CBN.6F.29 showed 2.8 cm and 0.394 U/mL (pH 5, 40°C) for its cellulase activity, while 2.3 cm and 0.439 U/mL (pH 8, 70°C) for its xylanase activity. Xylanase from HL.47F.216 and CBN.6F.29 showed low molecular masses of 20 kDa and 37-50 kDa, respectively. Molecular masses for cellulases from HL.51F.235 and CBN.6F.29 were 25 and 50 kDa for HL.51F.235 and 100 kDa for CBN.6F.29. Based on macroscopic and microscopic identification, fungal isolate CBN.6F.29 is a member of Class Coelomycetes, while HL.47F.216 was Acremonium sp. and HL.51F.235 was Aspergillus nigri.

Utilization of deoiled Jatropha curcas seed cake for production of xylanase from thermophilic Scytalidium thermophilum.

Science.gov (United States)

Joshi, Chetna; Khare, S K

2011-01-01

Jatropha curcas is a major biodiesel crop. Large amount of deoiled cake is generated as by-product during biodiesel production from its seeds. Deoiled J. curcas seed cake was assessed as substrate for the production of xylanase from thermophilic fungus Scytalidium thermophilum by solid-state fermentation. The seed cake was efficiently utilized by S. thermophilum for its growth during which it produced good amount of heat stable extracellular xylanase. The solid-state fermentation conditions were optimized for maximum xylanase production. Under the optimized conditions viz. deoiled seed cake supplemented with 1% oat-spelt xylan, adjusted to pH 9.0, moisture content 1:3 w/v, inoculated with 1×10(6) spores per 5 g cake and incubated at 45 °C, 1455 U xylanase/g deoiled seed cake was obtained. The xylanase was useful in biobleaching of paper pulp. Solid-state fermentation of deoiled cake appears a potentially viable approach for its effective utilization. Copyright © 2010 Elsevier Ltd. All rights reserved.

Purification and characterization of a thermostable hypothetical xylanase from Aspergillus oryzae HML366.

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He, Haiyan; Qin, Yongling; Li, Nan; Chen, Guiguang; Liang, Zhiqun

2015-03-01

In the current study, fermentation broth of Aspergillus oryzae HML366 in sugar cane bagasse was subjected to ultrafiltration and ion exchange chromatography, and two xylanases, XynH1 and XynH2, were purified. Time-of-flight mass spectrometry coupled with SDS-PAGE analysis revealed that XynH1 is identical to the hypothetical A. oryzae RIB40 protein XP_001826985.1, with a molecular weight of 33.671 kDa. Likewise, XynH2 was identified as xylanase XynF1 with a molecular weight of 35.402 kDa. Sequence analysis indicated that XynH1 belongs to glycosyl hydrolases family 10. The specific activity of XynH1 was measured at 476.9 U/mg. Optimal xylanase activity was observed at pH 6.0, and enzyme remained active within pH 4.0-10.0 and at a temperature below 70 °C. Mg(2+), Mn(2+), Ca(2+), and K(+) enhanced the XynH1 xylanase activity to 146, 122, 114, and 108%, respectively. XynH1 hydrolyzed Birchwood xylan and Larchwood xylan effectively. The K m and V max of XynH1 values determined were 1.16 mM and 336 μmol/min/mg with Birchwood xylan as the substrate. A. oryzae HML366 xylanase XynH1 showed superior heat and pH tolerance, therefore may have significant applications in paper and biofuel industries. These studies constitute the first investigation of the xylanase activities of the hypothetical protein XP_001826985.1 form A. oryzae.

Xylanase supplementation on enzymatic saccharification of dilute acid pretreated poplars at different severities

Science.gov (United States)

Chao Zhang; Xinshu Zhuang; Zhao Jiang Wang; Fred Matt; Franz St. John; J.Y. Zhu

2013-01-01

Three pairs of solid substrates from dilute acid pretreatment of two poplar wood samples were enzymatically hydrolyzed by cellulase preparations supplemented with xylanase. Supplementation of xylanase improved cellulose saccharification perhaps due to improved cellulose accessibility by xylan hydrolysis. Total xylan removal directly affected enzymatic cellulose...

Simultaneous Silencing of Xylanase Genes in Botrytis cinerea

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Néstor García

2017-12-01

Full Text Available The endo-β-1,4-xylanase BcXyn11A is one of several plant cell-wall degrading enzymes that the phytopathogenic fungus Botrytis cinerea secretes during interaction with its hosts. In addition to its enzymatic activity, this protein also acts as an elicitor of the defense response in plants and has been identified as a virulence factor. In the present work, other four endoxylanase coding genes (Bcxyn11B, Bcxyn11C, Bcxyn10A, and Bcxyn10B were identified in the B. cinerea genome and the expression of all five genes was analyzed by Q-RT- PCR in vitro and in planta. A cross-regulation between xylanase genes was identified analyzing their expression pattern in the ΔBcxyn11A mutant strain and a putative BcXyn11A-dependt induction of Bcxyn10B gene was found. In addition, multiple knockdown strains were obtained for the five endoxylanase genes by transformation of B. cinerea with a chimeric DNA construct composed of 50-nt sequences from the target genes. The silencing of each xylanase gene was analyzed in axenic cultures and during infection and the results showed that the efficiency of the multiple silencing depends on the growth conditions and on the cross-regulation between them. Although the simultaneous silencing of the five genes was observed by Q-RT-PCR when the silenced strains were grown on medium supplemented with tomato extract, the endoxylanase activity measured in the supernatants was reduced only by 40%. Unexpectedly, the silenced strains overexpressed the Bcxyn11A and Bcxyn11C genes during the infection of tomato leaves, making difficult the analysis of the role of the endo-β-1,4-xylanases in the virulence of the fungus.

Production and characterization of thermostable xylanase from ...

African Journals Online (AJOL)

ajl2

2013-02-20

Feb 20, 2013 ... produced from Trichoderma (Huitron et al., 2008). Only a ... around their colonies against a red background, were selected and .... Resistance to antibiotic ..... Xylanases of marine fungi potential use for biobleaching of paper.

Xylanase production by a local fungal isolate, Aspergillus niger USM AI 1 via solid state

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Ibrahim Che Omar

2005-03-01

Full Text Available Isolate USM A1 I which was identified to be Aspergillus niger was selected as a potential producer of xylanase via a solid state fermentation system (SSF using palm kernel cake (PKC as substrate. The modification of the physical conditions of the SSF system indicated that the xylanase activity was 23.97 U/g PKC at the moisture ratio of 1:0.75 of PKC: moistening agent with the inoculum size of 1¥104 spores/ml and cultivated at the ambient temperature (28±3ºC. The supplementation of additional carbon and nitrogen sources in the PKC medium could enhance enzyme productivity. The maximum production of xylanase and growth obtained with the supplementation of xylose at 0.75% (w/w were 25.40 U/g and 1.69 mg glucosamine/ g PKC. Moreover, the presence of NaNO3 at 0.075% (w/w as additional nitrogen source further enhanced xylanase production to 33.99 U/g PKC although the growth remained unchanged at about 1.67 mg glucosa- mine/g PKC. The optimized conditions showed an increased xylanase production by 157% compared to before the optimization of the SSF system. The xylanase productivity was 23.12 U/mg glucosamine after optimization and 11.72 U/mg glucosamine before optimization.

Production, Purification, and Characterization of a Major Penicillium glabrum Xylanase Using Brewer's Spent Grain as Substrate

Science.gov (United States)

Beitel, Susan Michelz; Fortkamp, Diana; Terrasan, César Rafael Fanchini; de Almeida, Alex Fernando

2013-01-01

In recent decades, xylanases have been used in many processing industries. This study describes the xylanase production by Penicillium glabrum using brewer's spent grain as substrate. Additionally, this is the first work that reports the purification and characterization of a xylanase using this agroindustrial waste. Optimal production was obtained when P. glabrum was grown in liquid medium in pH 5.5, at 25 °C, under stationary condition for six days. The xylanase from P. glabrum was purified to homogeneity by a rapid and inexpensive procedure, using ammonium sulfate fractionation and molecular exclusion chromatography. SDS-PAGE analysis revealed one band with estimated molecular mass of 18.36 kDa. The optimum activity was observed at 60 °C, in pH 3.0. The enzyme was very stable at 50 °C, and high pH stability was verified from pH 2.5 to 5.0. The ion Mn2+ and the reducing agents β-mercaptoethanol and DTT enhanced xylanase activity, while the ions Hg2+, Zn2+, and Cu2+ as well as the detergent SDS were strong inhibitors of the enzyme. The use of brewer's spent grain as substrate for xylanase production cannot only add value and decrease the amount of this waste but also reduce the xylanase production cost. PMID:23762855

Production, Purification, and Characterization of a Major Penicillium glabrum Xylanase Using Brewer's Spent Grain as Substrate

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Adriana Knob

2013-01-01

Full Text Available In recent decades, xylanases have been used in many processing industries. This study describes the xylanase production by Penicillium glabrum using brewer's spent grain as substrate. Additionally, this is the first work that reports the purification and characterization of a xylanase using this agroindustrial waste. Optimal production was obtained when P. glabrum was grown in liquid medium in pH 5.5, at 25 °C, under stationary condition for six days. The xylanase from P. glabrum was purified to homogeneity by a rapid and inexpensive procedure, using ammonium sulfate fractionation and molecular exclusion chromatography. SDS-PAGE analysis revealed one band with estimated molecular mass of 18.36 kDa. The optimum activity was observed at 60 °C, in pH 3.0. The enzyme was very stable at 50 °C, and high pH stability was verified from pH 2.5 to 5.0. The ion Mn2+ and the reducing agents β-mercaptoethanol and DTT enhanced xylanase activity, while the ions Hg2+, Zn2+, and Cu2+ as well as the detergent SDS were strong inhibitors of the enzyme. The use of brewer's spent grain as substrate for xylanase production cannot only add value and decrease the amount of this waste but also reduce the xylanase production cost.

Effects of structure and xylanase treatment of brewers' spent grain on performance and nutrient availability in broiler chickens.

Science.gov (United States)

Denstadli, V; Westereng, B; Biniyam, H G; Ballance, S; Knutsen, S H; Svihus, B

2010-06-01

1. A factorial (2 x 3) feeding trial was set up to investigate the effects of coarse or finely ground brewers' spent grain (BSG) and xylanase treatment, either with no xylanase, top-dressed with xylanase or pre-treated with xylanase. 2. The experimental diets shared the same basal formulation and were fed to male broiler chickens (Ross 308) housed in individual cages from 12 to 29 d of age. 3. Xylanase pre-treatment reduced the dietary concentration of arabinoxylan by 15-30%. Pellet durability increased when BSG was ground. 4. Feed utilisation was significantly higher (6%) when the birds were given coarse BSG rather than ground BSG, whereas there was no significant effect of enzyme treatment. Apparent metabolisable energy was unaffected by the dietary treatments. 5. The overall starch digestibility was high (99%), with no dietary differences, whereas ileal protein digestibility was low (57%). Xylanase top-dressing tended to improve ileal protein digestibility but, in general, xylanase treatment had no major effect on overall performance in male broilers given diets with BSG.

Reuse of wastewater from pulp industry for the optimization of fungal xylanase production

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Geisiany Maria de Queiroz-Fernandes

2017-05-01

Full Text Available The production of enzymes using agro-industrial waste is a low cost alternative for the reuse of byproducts, with the subsequent impact decrease on the environment. Current analysis produced xylanase using fungus Aspergillus niger, with two types of wastewater generated during the pulp chemical bleaching phase as inducers. Xylanase was produced by submerged liquid fermentation and factorial design optimized parameters that influence production (concentration of wastewater and production period. Initial culture conditions (pH, temperature and agitation were optimized independently. Alkaline wastewater was more effective than acidic wastewater for the induction of xylanase in optimized conditions: 50% of culture medium, 7-day production, 30°C, pH 6.0 and agitation at 160 rpm. Despite different results, acidic and alkaline wastewaters induced xylanase production by A. niger when employed in concentrations lower than or equal to 50% of culture medium and in the most optimal conditions described above. Alkaline wastewater is highlighted as the most efficient for such production.

Xylanase production from marine derived Trichoderma pleuroticola 08ÇK001 strain isolated from Mediterranean coastal sediments.

Science.gov (United States)

Korkmaz, Melih N; Ozdemir, Sennur C; Uzel, Ataç

2017-10-01

Xylanases constitutes one the most important enzymes with diverse applications in different industries such as bioethanol production, animal feedstock production, production of xylo-oligosaccharides, baking industry, paper and pulp industry, xylitol production, fruit juice, and beer finishing, degumming, and agriculture. Currently, industrial xylanases are mainly produced by Aspergillus and Trichoderma members. Since the marine environments are less studied compared to terrestrial environments and harbors great microbial diversity we aimed to investigate the xylanase production of 88 marine-derived filamentous fungal strains. These strains are semi-quantitatively screened for their extracellular xylanase production and Trichoderma pleuroticola 08ÇK001 xylanase activity was further characterized. Optimum pH and temperature was determined as 5.0 and 50 °C, respectively. The enzyme preparation retained 53% of its activity at pH 5.0 after 1 h and have found resistant against several ions and compounds such as K + , Ba 2+ , Na + , β-mercaptoethanol, Triton X-100 and toluene. This study demonstrates that marine-derived fungal strains are prolific sources for xylanase production and presents the first report about the production and characterization of xylanase from a marine derived T. pleuroticola strain. The characteristics of T. pleuroticola 08ÇK001 xylanase activity indicate possible employment in some industrial processes such as animal feed, juice and wine industries or paper pulping applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Phylogenetic diversity and environment-specific distributions of glycosyl hydrolase family 10 xylanases in geographically distant soils.

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Guozeng Wang

Full Text Available BACKGROUND: Xylan is one of the most abundant biopolymers on Earth. Its degradation is mediated primarily by microbial xylanase in nature. To explore the diversity and distribution patterns of xylanase genes in soils, samples of five soil types with different physicochemical characters were analyzed. METHODOLOGY/PRINCIPAL FINDINGS: Partial xylanase genes of glycoside hydrolase (GH family 10 were recovered following direct DNA extraction from soil, PCR amplification and cloning. Combined with our previous study, a total of 1084 gene fragments were obtained, representing 366 OTUs. More than half of the OTUs were novel (identities of <65% with known xylanases and had no close relatives based on phylogenetic analyses. Xylanase genes from all the soil environments were mainly distributed in Bacteroidetes, Proteobacteria, Acidobacteria, Firmicutes, Actinobacteria, Dictyoglomi and some fungi. Although identical sequences were found in several sites, habitat-specific patterns appeared to be important, and geochemical factors such as pH and oxygen content significantly influenced the compositions of xylan-degrading microbial communities. CONCLUSION/SIGNIFICANCE: These results provide insight into the GH 10 xylanases in various soil environments and reveal that xylan-degrading microbial communities are environment specific with diverse and abundant populations.

Developing a xylanase XYNZG from Plectosphaerella cucumerina for baking by heterologously expressed in Kluyveromyces lactis.

Science.gov (United States)

Zhan, Fei Xiang; Wang, Qin Hong; Jiang, Si Jing; Zhou, Yu Ling; Zhang, Gui Min; Ma, Yan He

2014-12-16

Xylanase can replace chemical additives to improve the volume and sensory properties of bread in the baking. Suitable baking xylanase with improved yield will promote the application of xylanase in baking industry. The xylanase XYNZG from the Plectosphaerella cucumerina has been previously characterized by heterologous expression in Pichia pastoris. However, P. pastoris is not a suitable host for xylanase to be used in the baking process since P. pastoris does not have GRAS (Generally Regarded As Safe) status and requires large methanol supplement during the fermentation in most conditions, which is not allowed to be used in the food industry. Kluyveromyces lactis, as another yeast expression host, has a GRAS status, which has been successfully used in food and feed applications. No previous work has been reported concerning the heterologous expression of xylanase gene xynZG in K. lactis with an aim for application in baking. The xylanase gene xynZG from the P. cucumerina was heterologously expressed in K. lactis. The recombinant protein XYNZG in K. lactis presented an approximately 19 kDa band on SDS-PAGE and zymograms analysis. Transformant with the highest halo on the plate containing the RBB-xylan (Remazol Brilliant Blue-xylan) was selected for the flask fermentation in different media. The results indicated that the highest activity of 115 U/ml at 72 h was obtained with the YLPU medium. The mass spectrometry analysis suggested that the hydrolytic products of xylan by XYNZG were mainly xylobiose and xylotriose. The results of baking trials indicated that the addition of XYNZG could reduce the kneading time of dough, increase the volume of bread, improve the texture, and have more positive effects on the sensory properties of bread. Xylanase XYNZG is successfully expressed in K. lactis, which exhibits the highest activity among the published reports of the xylanase expression in K. lactis. The recombinant XYNZG can be used to improve the volume and sensory

Xylanases, nucleic acids encoding them and methods for making and using them

Energy Technology Data Exchange (ETDEWEB)

Gray, Kevin A.; Dirmeier, Richard

2018-02-27

The invention relates to enzymes having xylanase, mannanase and/or glucanase activity, e.g., catalyzing hydrolysis of internal .beta.-1,4-xylosidic linkages or endo-.beta.-1,4-glucanase linkages; and/or degrading a linear polysaccharide beta-1,4-xylan into xylose. Thus, the invention provides methods and processes for breaking down hemicellulose, which is a major component of the cell wall of plants, including methods and processes for hydrolyzing hemicelluloses in any plant or wood or wood product, wood waste, paper pulp, paper product or paper waste or byproduct. In addition, methods of designing new xylanases, mannanases and/or glucanases and methods of use thereof are also provided. The xylanases, mannanases and/or glucanases have increased activity and stability at increased pH and temperature.

Xylanases, nucleic acids encoding them and methods for making and using them

Science.gov (United States)

Gray, Kevin A; Dirmeier, Reinhard

2013-07-16

The invention relates to enzymes having xylanase, mannanase and/or glucanase activity, e.g., catalyzing hydrolysis of internal .beta.-1,4-xylosidic linkages or endo-.beta.-1,4-glucanase linkages; and/or degrading a linear polysaccharide beta-1,4-xylan into xylose. Thus, the invention provides methods and processes for breaking down hemicellulose, which is a major component of the cell wall of plants, including methods and processes for hydrolyzing hemicelluloses in any plant or wood or wood product, wood waste, paper pulp, paper product or paper waste or byproduct. In addition, methods of designing new xylanases, mannanases and/or glucanases and methods of use thereof are also provided. The xylanases, mannanases and/or glucanases have increased activity and stability at increased pH and temperature.

Production and characterization of xylanase from Bacillus thermoalkalophilus grown on agricultural wastes

Energy Technology Data Exchange (ETDEWEB)

Rajaram, S.; Varma, A. (Jawaharlal Nehru Univ., New Delhi (India). School of Life Sciences)

1990-10-01

Bacillus thermoalkalophilus isolated from termite-infested mound soils of the semi-arid zones of India had the ability to produce good amounts of xylanase(s) from cheap agricultural wastes. Of the two hemicellulosic substrates tested, bagasse was found to be the better inducer for xylanase production. Alkali treatment of bagasse and rice husk had varied effects on enzyme production. The enzyme preparation had activity optima at 60deg C and 70deg C and a half-life of 60 min at 65deg C. The enzyme was stable for 24 h over a pH range of 4.0-6.0, while maximum activity was observed at pH 6.0-7.0. Enzyme production and activity were inhibited by the end-product of xylan hydrolysis, xylose. (orig.).

Purification and characterization of xylanase from Aspergillus ...

African Journals Online (AJOL)

Xylanase was subjected to a three-step purification scheme involving ammonium sulphate precipitation, gel filtration chromatography and anion exchange chromatography. Purity was verified by running the extracted protein on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and a single band was ...

A novel halotolerant xylanase from marine isolate Bacillus subtilis cho40: gene cloning and sequencing

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, R.; Verma, P.; Deobagkar, D.

A novel halotolerant xylanase from marine bacterium Bacillus subtilis cho40 isolated from Chorao island of Mandovi estuary Goa, India has been reported. Extracellular xylanase was produced by using agricultural residue such as wheat bran as carbon...

Cloning and expression of an endo-1,4-β-xylanase from the coffee berry borer, Hypothenemus hampei

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Padilla-Hurtado Beatriz

2012-01-01

Full Text Available Abstract Background The coffee berry borer, Hypothenemus hampei, reproduces and feeds exclusively on the mature endosperm of the coffee seed, which has a cell wall composed mainly of a heterogeneous mixture of hemicellulose polysaccharides, including arabinoxylans. Xylanases are digestive enzymes responsible for the degradation of xylan based polymers, hydrolyzing them into smaller molecules that are easier to assimilate by insects. We report the cloning, expression and enzymatic characterization of a xylanase gene that was identified in the digestive tract of the coffee berry borer. Methods The complete DNA sequence encoding a H. hampei xylanase (HhXyl was obtained using a genome walking technique in a cDNA library derived from the borer digestive tract. The XIP-I gene was amplified from wheat (Triticum aestivum variety Soisson. A Pichia pastoris expression system was used to express the recombinant form of these enzymes. The xylanase activity and XIP-I inhibitory activity was quantified by the 3,5-dinitrosalicylic (DNS. The biological effects of XIP-I on borer individuals were evaluated by providing an artificial diet enriched with the recombinant XIP-I protein to the insects. Results The borer xylanase sequence contains a 951 bp open reading frame that is predicted to encode a 317-amino acid protein, with an estimated molecular weight of 34.92 kDa and a pI of 4.84. Bioinformatic analysis revealed that HhXyl exhibits high sequence homology with endo-β-D-xylanases of Streptomyces bingchenggensis from glycosyl hydrolase 10 (GH10. The recombinant xylanase showed maximal activity at pH 5.5 and 37°C. XIP-I expressed as a recombinant protein inhibited HhXyl activity in vitro and caused individual H. hampei mortality in bioassays when included as a supplement in artificial diets. Conclusion A xylanase from the digestive tract of the coffee berry borer was identified and functionally characterized. A xylanase inhibitor protein, XIP-I, from wheat was

Statistical optimization of thermo-alkali stable xylanase production from Bacillus tequilensis strain ARMATI

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Ameer Khusro

2016-07-01

Conclusions: The cellulase-free xylanase showed an alkali-tolerant and thermo-stable property with potentially applicable nature at industrial scale. This statistical approach established a major contribution in enzyme production from the isolate by optimizing independent factors and represents a first reference on the enhanced production of thermo-alkali stable cellulase-free xylanase from B. tequilensis.

Heterologous Expression of Xylanase II from Aspergillus usamii in Pichia pastoris

OpenAIRE

Zhou, Chenyan; Wang, Yongtao; Wu, Minchen; Wang, Wu; Li, Dongfeng

2009-01-01

To efficiently produce xylanase for food processing industry, a gene encoding xylanase II (XynII) from Aspergillus usamii has been cloned into the vector pPIC9K and integrated into the genome of Pichia pastoris KM71 by electroporation. By means of minimal dextrose (MD) plates and PCR, the recombinant P. pastoris strains (His+Muts) have been obtained. Activity assay and SDS-PAGE demonstrate that XynII was extracellularly expressed in P. pastoris with the induction of methanol. In shake flask c...

Optimization of biosynthesis conditions and catalitic behavior evaluation of cellulase-free xylanase produced by a new Streptomyces sp. strain

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GABRIELA BAHRIM

2011-07-01

Full Text Available Cellulase-free xylanase by Streptomyces sp.P12-137 was obtained bycultivation on the wheat bran as the sole carbon source. The effect of carbon and nitrogen sources and a ratio of them on the cellulase-free xylanase production was investigated. The new isolate Streptomyces sp. strain was able to grow in submerged system and to produce an increased level of xylanase. Wheat bran induced xylanase biosynthesis yield at a high level (9.27 UA/ml. For economical reasons cultivation was achieved on a cheap fermentative medium represented by agro-industrial wastes. The optima of the pH and temperature of the crude xylanase activity were 5.5 and 70°C,respectively.

Xylanase, CM-cellulase and avicelase production by the thermophilic fungus Sporotrichum thermophile

Energy Technology Data Exchange (ETDEWEB)

Margaritis, A; Merchant, R; Yaguchi, M

1983-01-01

When wheat straw was used as C source, S. thermophile produced large amounts of xylanase extracellularly in addition to CM-cellulase and Avicelase. These enzymes were isolated by alcohol precipitation, desalting, and column chromatography. The molecular weights were estimated to be 25,0065,000 and 84,000 for xylanase, CM-cellulase, and Avicelase, respectively. Serine and threonine were the most abundant amino acids and these enzymes are very acidic proteins.

Influence of agitation speeds and aeration rates on the Xylanase activity of Aspergillus niger SS7

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Yasser Bakri

2011-08-01

Full Text Available In this study, the effect of agitation and aeration rates on xylanase activity of Aspergillus niger SS7 in 3-litre stirred tank bioreactor was investigated. The agitation rates tested were 100, 200 and 300 rpm at each airflow rates of 0.5, 1.0 and 1.5 vvm. The maximum xylanase activity in mono- agitator system was at the agitation speed of 200 rpm and aeration rate of 1.0 vvm. In bi-agitator system, at low agitation speed (100 rpm, the xylanase activity was enhanced by 13% compared to mono- agitator system for an aeration rate of 1.0 vvm. Xylanase productivity in continuous culture was higher by approximately 3.5 times than in batch culture.

Thermoactive cellulase-free xylanase production from alkaliphilic ...

African Journals Online (AJOL)

STORAGESEVER

2010-01-04

Jan 4, 2010 ... The enzymatic hydrolysis of xylan, a major hemicellulose ... agar (glucose replaced by 1.0% w/v Birch-Wood Xylan (BW-X, ..... Thermal stability was determined by preincubating the xylanase at pH 9.0; at 60.0°C for 1 h.

Solid-state Fermentation of Xylanase from Penicillium canescens 10-10c in a Multi-layer-packed Bed Reactor

Science.gov (United States)

Assamoi, Antoine A.; Destain, Jacqueline; Delvigne, Frank; Lognay, Georges; Thonart, Philippe

Xylanase is produced by Penicillium canescens 10-10c from soya oil cake in static conditions using solid-state fermentation. The impact of several parameters such as the nature and the size of inoculum, bed-loading, and aeration is evaluated during the fermentation process. Mycelial inoculum gives more production than conidial inoculum. Increasing the quantity of inoculum enhances slightly xylanase production. Forced aeration induces more sporulation of strain and reduces xylanase production. However, forced moistened air improves the production compared to production obtained with forced dry air. In addition, increasing bed-loading reduces the specific xylanase production likely due to the incapacity of the Penicillium strain to grow deeply in the fermented soya oil cake mass. Thus, the best cultivation conditions involve mycelial inoculum form, a bed loading of 1-cm height and passive aeration. The maximum xylanase activity is obtained after 7 days of fermentation and attains 10,200 U/g of soya oil cake. These levels are higher than those presented in the literature and, therefore, show all the potentialities of this stock and this technique for the production of xylanase.

Emerging role of N- and C-terminal interactions in stabilizing (β/α8 fold with special emphasis on Family 10 xylanases

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Amit Bhardwaj

2012-09-01

Full Text Available Xylanases belong to an important class of industrial enzymes. Various xylanases have been purified and characterized from a plethora of organisms including bacteria, marine algae, plants, protozoans, insects, snails and crustaceans. Depending on the source, the enzymatic activity of xylanases varies considerably under various physico-chemical conditions such as temperature, pH, high salt and in the presence of proteases. Family 10 or glycosyl hydrolase 10 (GH10 xylanases are one of the well characterized and thoroughly studied classes of industrial enzymes. The TIM-barrel fold structure which is ubiquitous in nature is one of the characteristics of family 10 xylanases. Family 10 xylanases have been used as a “model system” due to their TIM-barrel fold to dissect and understand protein stability under various conditions. A better understanding of structure-stability-function relationships of family 10 xylanases allows one to apply these governing molecular rules to engineer other TIM-barrel fold proteins to improve their stability and retain function(s under adverse conditions. In this review, we discuss the implications of N-and C-terminal interactions, observed in family 10 xylanases on protein stability under extreme conditions. The role of metal binding and aromatic clusters in protein stability is also discussed. Studying and understanding family 10 xylanase structure and function, can contribute to our protein engineering knowledge.

EMERGING ROLE OF N- AND C-TERMINAL INTERACTIONS IN STABILIZING (β;/α8 FOLD WITH SPECIAL EMPHASIS ON FAMILY 10 XYLANASES

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Amit Bhardwaj

2012-09-01

Full Text Available Xylanases belong to an important class of industrial enzymes. Various xylanases have been purified and characterized from a plethora of organisms including bacteria, marine algae, plants, protozoans, insects, snails and crustaceans. Depending on the source, the enzymatic activity of xylanases varies considerably under various physico-chemical conditions such as temperature, pH, high salt and in the presence of proteases. Family 10 or glycosyl hydrolase 10 (GH10 xylanases are one of the well characterized and thoroughly studied classes of industrial enzymes. The TIM-barrel fold structure which is ubiquitous in nature is one of the characteristics of family 10 xylanases. Family 10 xylanases have been used as a “model system” due to their TIM-barrel fold to dissect and understand protein stability under various conditions. A better understanding of structure-stability-function relationships of family 10 xylanases allows one to apply these governing molecular rules to engineer other TIM-barrel fold proteins to improve their stability and retain function(s under adverse conditions. In this review, we discuss the implications of N-and C-terminal interactions, observed in family 10 xylanases on protein stability under extreme conditions. The role of metal binding and aromatic clusters in protein stability is also discussed. Studying and understanding family 10 xylanase structure and function, can contribute to our protein engineering knowledge.

Xylanase, protease and superdosing phytase interactions in broiler performance, carcass yield and digesta transit time

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Tiago T. dos Santos

2017-06-01

Full Text Available The interaction of xylanase, protease and superdosing (1,500 FTU/kg phytase in a 2 × 2 × 2 factorial arrangement was studied in broilers fed sorghum-based diets. A total of 2,800 one-day-old unsexed Ross 308 chicks were housed in 56 pens with 50 birds per pen, with or without inclusion of xylanase, protease and phytase, totaling 8 treatments and 7 replicates per treatment. Body weight (BW and feed intake (FI were measured at 21 and 42 days of age, and mortality corrected feed conversion ratio (FCR was calculated for each period and cumulatively. Tibia ash and carcass yield were determined in 2 birds per replicate at 21 and 42 days of age, respectively. Digesta transit time was determined at 21, 28, 35 and 42 days of age using 5 birds per replicate. Results showed that superdosing phytase increased BW and FI at 42 days of age (P < 0.05 and xylanase improved FCR (P < 0.05. Xylanase and phytase also positively influenced carcass yield and breast weight, respectively. Overall, inclusion of superdosing phytase increased transit time when included in a diet containing xylanase, and no change with protease inclusion. In conclusion, the beneficial effects of xylanase, protease and superdosing phytase in broiler performance were not additive. This limitation is likely not related to the lack of efficacy of any one of the individual enzymes but to a limitation of the bird to respond additively to successive additions of enzymes.

Alkalistable endo-β-1,4-xylanase production from a newly isolated alkalitolerant Penicillium sp. SS1 using agro-residues.

Science.gov (United States)

Bajaj, Bijender Kumar; Sharma, Mukul; Sharma, Sunny

2011-09-01

Thermostable and alkalitolerant xylanases have got intense research focus due to their vast applications in various industries including pulp and paper, food, feed, textile, biofuel, etc. In the present investigation, a Penicillum sp. SS1 isolated from degrading woody material was found to produce moderately thermoactive and alkalistable endo-β-1,4-xylanase (xylanase). Maximum xylanase production was observed after fourth day of fermentation (43.84 IU/ml). The organism produced substantial quantities of xylanase using agricultural residues like wheat bran (20.6 IU/ml), rice bran (21.8 IU/ml) and sawdust (10.7 IU/ml) as carbon sources. The enzyme preparation was totally free of filter paper activity (FPase) and possessed negligible carboxymethyl cellulase (CMCase) activity; this could be an important feature of enzyme if the intended application of enzyme is in pulp and paper industries. Among nitrogen sources examined, yeast extract supported maximum xylanase production (45.74 IU/ml), and was followed by soybean meal (22.2 IU/ml) and ammonium sulphate (20 IU/ml). Maximum xylanase production was observed at initial medium pH 9 (25.6 IU/ml); however, at pH 8 and 10 also significantly high enzyme titre was observed (24 and 21.2 IU/ml, respectively). Thus, Penicillium sp. SS1 displayed capability of growing and producing xylanase at high alkaline pH (8-10). Maximum xylanase activity was reported at 50 °C, however, significantly high activity was observed at 60 °C (65.4%), however, at 70-80 °C activity was lost considerably. At 50-60 °C the enzyme retained very high activity up to 30-60 min (91-100%), however, prolonged incubation (90 min) caused considerable activity reduction (residual activity 63-68%).

Ecofriendly application of cellulase and xylanase producing marine ...

African Journals Online (AJOL)

windows

2012-06-05

Jun 5, 2012 ... producing marine Streptomyces clavuligerus as enhancer in ... pretreatment of cellulase, xylanase and the combination of enzymes. ... Energy from biomass holds a promising scope under ... investment, simplification of the fermentation media, ... biodegradation of lignocellulosic residues and enhanced ...

Polypeptides having xylanase activity and polynucleotides encoding same

Energy Technology Data Exchange (ETDEWEB)

Spodsberg, Nikolaj

2018-02-06

The present invention relates to isolated polypeptides having xylanase activity and polynucleotides encoding the polypeptides. The invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides.

Sequential and simultaneous strategies for biorefining of wheat straw using room temperature ionic liquids, xylanases and cellulases.

Science.gov (United States)

Husson, Eric; Auxenfans, Thomas; Herbaut, Mickael; Baralle, Manon; Lambertyn, Virginie; Rakotoarivonina, Harivoni; Rémond, Caroline; Sarazin, Catherine

2018-03-01

Sequential and simultaneous strategies for fractioning wheat straw were developed in combining 1-ethyl-3-methyl imidazolium acetate [C2mim][OAc], endo-xylanases from Thermobacillus xylanilyticus and commercial cellulases. After [C2mim][OAc]-pretreatment, hydrolysis catalyzed by endo-xylanases of wheat straw led to efficient xylose production with very competitive yield (97.6 ± 1.3%). Subsequent enzymatic saccharification allowed achieving a total degradation of cellulosic fraction (>99%). These high performances revealed an interesting complementarity of [C2mim][OAc]- and xylanase-pretreatments for increasing enzymatic digestibility of cellulosic fraction in agreement with the structural and morphological changes of wheat straw induced by each of these pretreatment steps. In addition a higher tolerance of endo-xylanases from T. xylaniliticus to [C2mim][AcO] until 30% v/v than cellulases from T. reesei was observed. Based on this property, a simultaneous strategy combining [C2mim][OAc]- and endo-xylanases as pretreatment in a one-batch produced xylose with similar yield than those obtained by the sequential strategy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of pH on production of xylanase by Trichoderma reesei on xylan- and cellulose-based media

Energy Technology Data Exchange (ETDEWEB)

Bailey, M.J. (VTT, Biotechnical Lab., Espoo (Finland)); Buchert, J. (VTT, Biotechnical Lab., Espoo (Finland)); Viikari, L. (VTT, Biotechnical Lab., Espoo (Finland))

1993-11-01

Trichoderma reesei VTT-D-86271 (Rut C-30) was cultivated on media based on cellulose and xylan as the main carbon source in fermentors with different pH minimum controls. Production of xylanase was favoured by a rather high pH minimum control between 6.0 and 7.0 on both cellulose- and xylan-based media. Although xylanase was produced efficiently on cellulose as well as on xylan as the carbon source, significant production of cellulase was observed only on the cellulose-based medium and best production was at lower pH (4.0 minimum). Production of xylanase at pH 7.0 was shown to be dependent on the nature of the xylan in the cultivation medium but was independent of other organic components. Best production of xylanase was observed on insoluble, unsubstituted beech xylan at pH 7.0. Similar results were obtained in laboratory and pilot (200-1) fermentors. Downstream processing of the xylanase-rich, low-cellulase culture filtrate presented no technical problems despite apparent autolysis of the fungus at the high pH. Enzyme produced in the 200-1 pilot fermentor was shown to be suitable for use in enzyme-aided bleaching of kraft pulp. Due to the high xylanase/cellulase ratio of enzyme activities in the culture filtrate, pretreatment for removal of cellulase activity prior to pulp bleaching was unnecessary. (orig.)

The expression of a xylanase targeted to ER-protein bodies provides a simple strategy to produce active insoluble enzyme polymers in tobacco plants.

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Immaculada Llop-Tous

Full Text Available BACKGROUND: Xylanases deserve particular attention due to their potential application in the feed, pulp bleaching and paper industries. We have developed here an efficient system for the production of an active xylanase in tobacco plants fused to a proline-rich domain (Zera of the maize storage protein γ-zein. Zera is a self-assembling domain able to form protein aggregates in vivo packed in newly formed endoplasmic reticulum-derived organelles known as protein bodies (PBs. METHODOLOGY/PRINCIPAL FINDINGS: Tobacco leaves were transiently transformed with a binary vector containing the Zera-xylanase coding region, which was optimized for plant expression, under the control of the 35S CaMV promoter. The fusion protein was efficiently expressed and stored in dense PBs, resulting in yields of up to 9% of total protein. Zera-xylanase was post-translationally modified with high-mannose-type glycans. Xylanase fused to Zera was biologically active not only when solubilized from PBs but also in its insoluble form. The resistance of insoluble Zera-xylanase to trypsin digestion demonstrated that the correct folding of xylanase in PBs was not impaired by Zera oligomerization. The activity of insoluble Zera-xylanase was enhanced when substrate accessibility was facilitated by physical treatments such as ultrasound. Moreover, we found that the thermostability of the enzyme was improved when Zera was fused to the C-terminus of xylanase. CONCLUSION/SIGNIFICANCE: In the present work we have successfully produced an active insoluble aggregate of xylanase fused to Zera in plants. Zera-xylanase chimeric protein accumulates within ER-derived protein bodies as active aggregates that can easily be recovered by a simple density-based downstream process. The production of insoluble active Zera-xylanase protein in tobacco outlines the potential of Zera as a fusion partner for producing enzymes of biotechnological relevance. Zera-PBs could thus become efficient and low

Cellulase-poor xylanases produced by Trichoderma reesei RUT C-30 on hemicellulose substrates

Energy Technology Data Exchange (ETDEWEB)

Gamerith, G.; Groicher, R. (Lenzing AG (Austria). Dept. of Research and Development); Zeilinger, S.; Herzog, P.; Kubicek, C.P. (Technische Univ., Vienna (Austria). Abt. fuer Mikrobielle Biochemie)

1992-12-01

Hemicellulose components from industrial viscose fibre production are characterized by a lower cellulose content than commerical xylan and the pressence of a carboxylic acid fraction originating from the alkaline degradation of carbohydrates during the process. This substrate, after neutralization, can be used by Trichoderma reesei RUT C-30 for the production of cellulase-poor xylanases, useful for the pulp and paper industry. The yields of xylanase ranged up to almost 400 units/ml, with a ratio of carboxymethylcellulase/xylanase of less than 0.015. This crude xylanase enzyme mixture was shown to be superior to that obtained on beech-wood xylan when used for bleaching and, particularly, upgrading of hard-wood chemical pulp by selective removal of the xylan components. Biochemical studies indicate that the low cellulase production by T. reesei grown on these waste hemicelluloses is the result of a combination of at least three factors: (a) The comparatively low content of cellulose in these hemicellulosic wastes, (b) the inhibitory action of the carboxylic acid fraction present in the hemicellulosic wastes on growth and sporulation of T. reesei, and (c) the use of a mycelial inoculum that is unable to initiate the atack on the cellulose components within the carbon source. (orig.).

Inexpensive, rapid procedure for bulk purification of cellulase-free. beta. -1,4-D-xylanase of high specific activity

Energy Technology Data Exchange (ETDEWEB)

Tan, L.U.L.; Yu, E.K.C.; Louis-Seize, G.W.; Saddler, J.N.

1987-01-01

A process has been developed for the bulk purification of cellulase-free ..beta..-14-D-xylanase from the fungus Tirchoderma harzianum E58. The process involved the primary step of ultrafiltering the culture filtrate via a 10,000-molecular-weight cut-off membrane to separate the cellulase (retentate) and xylanase (permeate) fractions. The cellulase component was concentrated by 40- to 60-fold, resulting in an enzyme complex that could effectively hydrolyze high concentrations of cellulose and xylan to glucose and xylose. The xylanase was concentrated and solvent exchanged by adsorption to a cationic exchanger, SP-ZetaPrep 250, followed by elution with a pH change in the buffer to give a purified and concentrated xylanase complex dissolved in a low-salt buffer. The resultant xylanase system was pure by the criteria of sodium dodecyl sulfate polyacrylamide electrophoresis, had a very high specific activity of 2400 IU/mg protein, was virtually free of filter paper activity, and had a ratio of contaminating filter paper activity of 2 x 10/sup -6/. Approximately 3.3 g protein, which contained in excess of 7 x 10/sup 6/ IU xylanase activity was obtained from 17 L original culture filtrate. The process scheme was designed to facilitate scale-up to an industrial level of production.

Partial purification and characterization of xylanase produced from aspergillus niger using wheat bran

International Nuclear Information System (INIS)

Ahmad, Z.; Butt, M.S.

2013-01-01

In present exploration, purification and characterization of xylanase was carried out to find its optimum conditions for maximum functionality. The xylanase (EC 3.2.1.8) synthesized by Aspergillus niger in submerged fermentation was partially purified and characterized for different parameters like temperature, pH and heat stability. The molecular mass determined through SDS-PAGE was found 30 kDa. The specific activity of the enzyme was raised from 41.85 to 613.13 with 48.63% yield just in a two step partial purification comprising ammonium sulphate precipitation and Sephadex gel filteration column chromatography. The partially purified enzyme was found to be optimally active at 60 degree C and 7.5 pH. Conclusively, for the application of xylanase in food, feed or paper manufacturing processes, it is necessary to consider its optimum pH and temperature. (author)

Production of xylanases by mangrove fungi from the Philippines and their application in enzymatic pretreatment of recycled paper pulps.

Science.gov (United States)

Torres, Jeremy Martin O; Dela Cruz, Thomas Edison E

2013-04-01

Mangrove fungi are vastly unexplored for enzymes with industrial application. This study aimed to assess the biocatalytic activity of mangrove fungal xylanases on recycled paper pulp. Forty-four mangrove fungal (MF) isolates were initially screened for xylanolytic activity in minimal medium with corn cob xylan as the sole carbon source. Eight MF were further cultivated under submerged fermentation for the production of crude xylanases. These crude enzymes were then characterized and tested for the pretreatment of recycled paper pulps. Results showed that 93 % of the tested MF isolates exhibited xylanolytic activity in solid medium. In submerged fermentation, salinity improved the growth of the fungal isolates but did not influence xylanase production. The crude xylanases were mostly optimally active at 50 °C and pH 7. Changes in pH had a greater effect on xylanase stability than temperature. More than half of the activity was lost at pH 9 for majority of the crude enzymes. However, two thermophilic xylanases from Fusarium sp. KAWIT-A and Aureobasidium sp. 2LIPA-M and one alkaliphilic xylanase from Phomopsis sp. MACA-J were also produced. All crude enzymes exhibited cellulase activities ranging from 4 to 21 U/ml. Enzymatic pretreatment of recycled paper pulps with 5 % consistency produced 70-650 mg of reducing sugars per gram of pulp at 50 °C after 60 min. The release of high amounts of reducing sugars showed the potential of mangrove fungal crude xylanases in the local paper and pulp industry. The diverse properties shown by the tested crude enzymes also indicate its potential applications to other enzyme-requiring industries.

Disruption of the L-arabitol dehydrogenase encoding gene in Aspergillus tubingensis results in increased xylanase production

NARCIS (Netherlands)

Nikolaev, I.; Hansen, S.; Madrid, S.; de Vries, R.P.

2013-01-01

Fungal xylanases are of major importance to many industrial sectors, such as food and feed, paper and pulp, and biofuels. Improving their production is therefore highly relevant. We determined the molecular basis of an improved xylanase-producing strain of Aspergillus tubingensis that was generated

Paddy Husk as Support for Solid State Fermentation to Produce Xylanase from Bacillus pumilus

Directory of Open Access Journals (Sweden)

Ranganathan KAPILAN

2011-03-01

Full Text Available To optimize culture conditions for xylanase production by solid state fermentation (SSF using Bacillus pumilus, with paddy husk as support, solid medium contained 200 g of paddy husk with 800 mL of liquid fermentation medium [xylan, 20.0 g/L; peptone, 2.0 g/L; yeast extract, 2.5 g/L; K2HPO4, 2.5 g/L; KH2PO4, 1.0 g/L; NaCl, 0.1 g/L; (NH42SO4, 2.0 g/L, CaCl2·2H2O, 0.005 g/L; MgCl2·6H2O, 0.005 g/L; and FeCl3, 0.005 g/L] at pH 9.0 was applied. The highest xylanase activity (142.0 ±0.47 U/g DM] was obtained on the 6th day at 30°C. The optimized paddy husk to liquid fermentation medium ratio was 2:9, and the optimized culture temperature was 40°C. When commercial Birchwood xylan was replaced with different concentrations of corncob, xylanase production was maximized (224.2 U/g DM in the medium with 150 g/L corncob. Xylanase production was increased by sucrose, fructose and arabinose, whereas reduced by glucose, galactose, lactose and amylose. When organic nitrogen sources were replaced with locally available nitrogen sources such as groundnut powder or sesame seedcake powder or coconut seedcake powder or soy meal powder, the highest xylanase production (290.7 U/g DM was obtained in the medium with soy meal powder and 16.0 g/L of soy meal powder was the optimum (326.5±0.34 U/g DM. Based on the optimization studies, B. pumilus produced 2.3 times higher xylanase activity. The medium cost was reduced from 2 458.3 to 178.3 SLR/kg and the total activity which could be obtained from 1 kg of the medium was increased from 48 624 to 220 253 Units.

Modeling process for bioproduction of xylanase by Streptomyces spp. p12-137 on lignocelluloses agro-wastes

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Gigi COMAN

2012-12-01

Full Text Available The production of xylanase without cellulase is required for the prebleaching of pulps, paper and food industry. The strain Streptomyces spp.P12-137 developed from the spores of the wild type organism was used in this work. Cultures in Erlenmeyer flasks, under shaking condition (150 rpm at temperature and pH values (28°C, 5.0 respectively revealed a xylanase activity of 27.77 IU·mL-1 after 120 h fermentation. This study demonstrates that Streptomyces spp. P12-137 is able to produce xylanase when wheat bran is used as a substrate. Fermentation was performed in a glass bioreactor withforced aeration. Data obtained have been compared to data from mathematical model obtained by numerical simulation using Matlab 7.9.0.529 (MathWorks, Inc. USA. The numerical simulation of the bioprocess could be a useful tool for adopting a control strategy to achieve increased xylanases yields under pilot or industrial conditions.

Variation in levels of non-starch polysaccharides and endogenous endo-1,4-β-xylanases affects the nutritive value of wheat for poultry.

Science.gov (United States)

Cardoso, V; Fernandes, E A; Santos, H M M; Maçãs, B; Lordelo, M M; Telo da Gama, Luis; Ferreira, L M A; Fontes, C M G A; Ribeiro, T

2018-04-01

1. Endo-1,4-β-xylanase is known to improve the nutritive value of wheat-based diets for poultry by degrading dietary arabinoxylans. However, broilers' response to supplementation of wheat-based diets with exogenous endo-1,4-β-xylanase is not always observed. 2. In this study, 108 different wheat lots were analysed for levels of extract viscosity as well as for endogenous endo-1,4-β-xylanase activity, and the impact of these two variables in animal performance was tested. 3. Results revealed that endogenous endo-1,4-β-xylanase activity and extract viscosity content varied widely among different wheat lots. Thus, a trial was conducted to evaluate the efficacy of exogenous enzyme supplementation in broiler diets using wheats with different levels of extract viscosity and endogenous endo-1,4-β-xylanase activity. 4. The data revealed that exogenous enzyme supplementation was only effective when the wheat present in the diet had high levels of extract viscosity (14.8 cP) with low endogenous endo-1,4-β-xylanase activity (347.0 U/kg). Nevertheless, it is apparent that exogenous microbial xylanases reduce digesta extract viscosity and feed conversion ratio independently of the endogenous properties presented by different wheat lots. 5. The data suggest that extract viscosity and/or endogenous endo-1,4-β-xylanase activity affect the response to enzyme supplementation by poultry fed on wheat-based diets.

Bifunctional xylanases and their potential use in biotechnology

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, R.; Numan, M.Th.

. J Chromatography 919:389–394 33. Hong SY, Lee JS, Cho KM, Math RK, Kim YH, Hong SJ, Cho YU, Kim H, Yun HD (2006) Assembling a novel bifunctional cel- lulase–xylanase from Thermotoga maritima by end-to-end fusion. Biotechnol Lett 28:1857–1862 34...

Development of a bifunctional xylanase-cellulase chimera with enhanced activity on rice and barley straws using a modular xylanase and an endoglucanase procured from camel rumen metagenome.

Science.gov (United States)

Khalili Ghadikolaei, Kamran; Akbari Noghabi, Kambiz; Shahbani Zahiri, Hossein

2017-09-01

The camel rumen metagenome is an untapped source of glycoside hydrolases. In this study, novel genes encoding for a modular xylanase (XylC) and a cellulase (CelC) were isolated from a camel rumen metagenome and expressed in Escherichia coli BL21 (DE3). XylC with xylanase (Xyn), CBM, and carbohydrate esterase (CE) domains was characterized as a β-1,4-endoxylanase with remarkable catalytic activity on oat-spelt xylan (K cat  = 2919 ± 57 s -1 ). The implication of XylC's modular structure in its high catalytic activity was analyzed by truncation and fusion construction with CelC. The resulting fusions including Cel-CBM, Cel-CBM-CE, and Xyn-CBM-Cel showed remarkable enhancement in CMCase activity with K cat values of 742 ± 12, 1289 ± 34.5, and 2799 ± 51 s -1 compared to CelC with a K cat of 422 ± 3.5 s -1 . It was also shown that the bifunctional Xyn-CBM-Cel with synergistic xylanase/cellulase activities was more efficient than XylC and CelC in hydrolysis of rice and barley straws.

Effect of Cellulases and Xylanases on Refining Process and Kraft Pulp Properties.

Directory of Open Access Journals (Sweden)

Kamila Przybysz Buzała

Full Text Available Samples of bleached kraft pine cellulosic pulp, either treated with an enzyme preparation (a Thermomyces lanuginosus xylanase, an Aspergillus sp. cellulase, and a multienzyme preparation NS-22086 containing both these activities or untreated, were refined in a laboratory PFI mill. The treatment with cellulases contained in the last two preparations significantly improved the pulp's susceptibility to refining (the target freeness value of 30°SR was achieved in a significantly shorter time, increased water retention value (WRV and fines contents while the weighted average fiber length was significantly reduced. These changes of pulp parameters caused deterioration of paper strength properties. The treatment with the xylanase, which partially hydrolyzed xylan, small amounts of which are associated with cellulose fibers, only slightly loosened the structure of fibers. These subtle changes positively affected the susceptibility of the pulp to refining (refining energy was significantly reduced and improved the static strength properties of paper. Thus, the treatment of kraft pulps with xylanases may lead to substantial savings of refining energy without negative effects on paper characteristics.

Thermal-induced conformational changes in the product release area drive the enzymatic activity of xylanases 10B: Crystal structure, conformational stability and functional characterization of the xylanase 10B from Thermotoga petrophila RKU-1

International Nuclear Information System (INIS)

Santos, Camila Ramos; Meza, Andreia Navarro; Hoffmam, Zaira Bruna; Silva, Junio Cota; Alvarez, Thabata Maria; Ruller, Roberto; Giesel, Guilherme Menegon; Verli, Hugo; Squina, Fabio Marcio; Prade, Rolf Alexander; Murakami, Mario Tyago

2010-01-01

Research highlights: → The hyperthermostable xylanase 10B from Thermotoga petrophila RKU-1 produces exclusively xylobiose at the optimum temperature. → Circular dichroism spectroscopy suggests a coupling effect of temperature-induced structural changes with its enzymatic behavior. → Crystallographic and molecular dynamics studies indicate that conformational changes in the product release area modulate the enzyme action mode. -- Abstract: Endo-xylanases play a key role in the depolymerization of xylan and recently, they have attracted much attention owing to their potential applications on biofuels and paper industries. In this work, we have investigated the molecular basis for the action mode of xylanases 10B at high temperatures using biochemical, biophysical and crystallographic methods. The crystal structure of xylanase 10B from hyperthermophilic bacterium Thermotoga petrophila RKU-1 (TpXyl10B) has been solved in the native state and in complex with xylobiose. The complex crystal structure showed a classical binding mode shared among other xylanases, which encompasses the -1 and -2 subsites. Interestingly, TpXyl10B displayed a temperature-dependent action mode producing xylobiose and xylotriose at 20 o C, and exclusively xylobiose at 90 o C as assessed by capillary zone electrophoresis. Moreover, circular dichroism spectroscopy suggested a coupling effect of temperature-induced structural changes with this particular enzymatic behavior. Molecular dynamics simulations supported the CD analysis suggesting that an open conformational state adopted by the catalytic loop (Trp297-Lys326) provokes significant modifications in the product release area (+1,+2 and +3 subsites), which drives the enzymatic activity to the specific release of xylobiose at high temperatures.

Thermal-induced conformational changes in the product release area drive the enzymatic activity of xylanases 10B: Crystal structure, conformational stability and functional characterization of the xylanase 10B from Thermotoga petrophila RKU-1

Energy Technology Data Exchange (ETDEWEB)

Santos, Camila Ramos; Meza, Andreia Navarro [Laboratorio Nacional de Biociencias (LNBio), Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP (Brazil); Hoffmam, Zaira Bruna; Silva, Junio Cota; Alvarez, Thabata Maria; Ruller, Roberto [Laboratorio Nacional de Ciencia e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP (Brazil); Giesel, Guilherme Menegon; Verli, Hugo [Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS (Brazil); Squina, Fabio Marcio [Laboratorio Nacional de Ciencia e Tecnologia do Bioetanol (CTBE), Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP (Brazil); Prade, Rolf Alexander [Department of Microbiology and Molecular Genetics, Oklahoma State University, Stillwater, OK (United States); Murakami, Mario Tyago, E-mail: mario.murakami@lnbio.org.br [Laboratorio Nacional de Biociencias (LNBio), Centro Nacional de Pesquisa em Energia e Materiais, Campinas, SP (Brazil)

2010-12-10

Research highlights: {yields} The hyperthermostable xylanase 10B from Thermotoga petrophila RKU-1 produces exclusively xylobiose at the optimum temperature. {yields} Circular dichroism spectroscopy suggests a coupling effect of temperature-induced structural changes with its enzymatic behavior. {yields} Crystallographic and molecular dynamics studies indicate that conformational changes in the product release area modulate the enzyme action mode. -- Abstract: Endo-xylanases play a key role in the depolymerization of xylan and recently, they have attracted much attention owing to their potential applications on biofuels and paper industries. In this work, we have investigated the molecular basis for the action mode of xylanases 10B at high temperatures using biochemical, biophysical and crystallographic methods. The crystal structure of xylanase 10B from hyperthermophilic bacterium Thermotoga petrophila RKU-1 (TpXyl10B) has been solved in the native state and in complex with xylobiose. The complex crystal structure showed a classical binding mode shared among other xylanases, which encompasses the -1 and -2 subsites. Interestingly, TpXyl10B displayed a temperature-dependent action mode producing xylobiose and xylotriose at 20 {sup o}C, and exclusively xylobiose at 90 {sup o}C as assessed by capillary zone electrophoresis. Moreover, circular dichroism spectroscopy suggested a coupling effect of temperature-induced structural changes with this particular enzymatic behavior. Molecular dynamics simulations supported the CD analysis suggesting that an open conformational state adopted by the catalytic loop (Trp297-Lys326) provokes significant modifications in the product release area (+1,+2 and +3 subsites), which drives the enzymatic activity to the specific release of xylobiose at high temperatures.

Screening of Thermophilic Bacteria Produce Xylanase from Sapan Sungai Aro Hot Spring South Solok

Science.gov (United States)

Irdawati, I.; Syamsuardi, S.; Agustien, A.; Rilda, Y.

2018-04-01

xylanase is one of the enzymes with great prospects as hemicellulose hydrolyzing enzyme. Global annual market demand for this enzyme reach US 200 million. This enzyme catalyzes the xylan (hemicellulose) reactions breaking into xilooligosakarida and xylose. Xylanase can be applied to various industrial sectors such as bread, sugar xylose, biofuels, especially in bleaching paper (bleaching) pulp. Xylanase Isable to replace conventional chemical bleaching using chlorine that is not friendly for the environment. Currently xylanase production is extracted from the thermophilic bacteria for enzyme stability at high temperatures that are suitable for industrial applications. Thermophilic bacteria can be isolated from a hot spring, one of the which is a source of Sapan Sungai Aro Hot Spring, located in the district South Solok. The aim of this study was to select and identification of thermophilic bacteria can produce xylanase.This roomates is a descriptive study, which was Carried out in the Laboratory of Microbiology, Mathematic and Science Faculty of Padang State University, and Laboratory of Bacteriology, BasoVeterinary Research Center. The research procedure consisted of the preparation and sterilization of materials and tools, medium manufacturing, regeneration, selection and identification. Selection is performed by using a semiquantitative screening plate that contains xylan substrate. Identification is based on microscopic and biochemical characteristics until the genus level.Selection results Showed 12 out of 16 isolates had xilanolitik activity, with the highest activity is SSA2 with xilanolitik index of 0.74. The top five index producehigestxilanolitik isolates that are SSA2, SSA3 and SSA4 identified as Bacillus sp. 1., and SSAS6 and SSA7 is Bacillus sp. 2.

Preparation of arabinoxylobiose from rye xylan using family 10 Aspergillus aculeatus endo-1,4-ß-d-xylanase

NARCIS (Netherlands)

Rantanen, H.; Virkki, L.; Tuomainen, P.; Kabel, M.A.; Schols, H.A.; Tenkanen, M.

2007-01-01

Commercial xylanase preparation Shearzyme®, which contains the glycoside hydrolase family 10 endo-1,4-ß-d-xylanase from Aspergillus aculeatus, was used to prepare short-chain arabinoxylo-oligosaccharides (AXOS) from rye arabinoxylan (AX). A major AXOS was formed as a hydrolysis product. Longer AXOS

High xylanase production by Trichoderma viride using pineapple ...

African Journals Online (AJOL)

Xylanases are hydrolases which depolymerize the xylan components present in plants cell wall. Commercial applications for these enzymes include its use in the pulp bleaching, food and animal feed industries, among others. Recently, there is a great interest on the exploitation of agro-industrial wastes as low-cost raw ...

Screening of culture condition for xylanase production by ...

African Journals Online (AJOL)

The study demonstrated not only the importance of the nature of the substrate in obtaining a system resistant to catabolic repression, but also the importance of the culture conditions for biosynthesis of this enzyme. T. viride showed a high potential for xylanase production under the conditions presented in these assays.

Enhanced production of xylanase from locally isolated fungal strain using agro-industrial residues under solid-state fermentation.

Science.gov (United States)

Abdullah, Roheena; Nisar, Kinza; Aslam, Aafia; Iqtedar, Mehwish; Naz, Shagufta

2015-01-01

This study is related to the isolation of fungal strain for xylanase production using agro-industrial residues. Forty fungal strains with xylanolytic potential were isolated by using xylan agar plates and quantitatively screened in solid-state fermentation. Of all the tested isolates, the strain showing highest ability to produce xylanase was assigned the code Aspergillus niger LCBT-14. For the enhanced production of the enzyme, five different fermentation media were evaluated. Out of all media, M4 containing wheat bran gave maximum enzyme production. Effect of different variables including incubation time, temperature, pH, carbon and nitrogen sources has been investigated. The optimum enzyme production was obtained after 72 h at 30°C and pH 4. Glucose as a carbon source while ammonium sulphate and yeast extract as nitrogen sources gave maximum xylanase production (946 U/mL/min). This study was successful in producing xylanase by A. niger LCBT-14 economically by utilising cheap indigenous substrate.

Isolation, Purification, and Characterization of Xylanase Produced by a New Species of Bacillus in Solid State Fermentation

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Rajashri D. Kamble

2012-01-01

Full Text Available A thermoalkalophilic new species of Bacillus, similar to Bacillus arseniciselenatis DSM 15340, produced extracellular xylanase under solid state fermentation when wheat bran is used as carbon source. The extracellular xylanase was isolated by ammonium sulfate (80% precipitation and purified using ion exchange chromatography. The molecular weight of xylanase was ~29.8 ;kDa. The optimum temperature and pH for the enzyme activity were 50°C and pH 8.0. The enzyme was active on birchwood xylan and little active on p-nitrophenyl xylopyranoside but not on Avicel, CMC, cellobiose, and starch, showing its absolute substrate specificity. For birchwood xylan, the enzyme gave a Km 5.26 ;mg/mL and Vmax 277.7 ;μmol/min/mg, respectively. In addition, the xylanase was also capable of producing high-quality xylo-oligosaccharides, which indicated its application potential not only in pulp biobleaching processes but also in the nutraceutical industry.

Potential of Laceyella sacchari strain B42 crude xylanase in ...

African Journals Online (AJOL)

rajmac

2013-02-06

Feb 6, 2013 ... sacchari strain B42. Maximal xylanase production was achieved at the incubation period of 48 h with ... chemicals for pulp processing and bleaching. The major ... industrial enzyme with great biotechnological application.

Evaluation of the effect of different wheats and xylanase supplementation on performance, nutrient and energy utilisation in broiler chicks

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Gemma González-Ortiz

2016-09-01

Full Text Available The aim of this study was to evaluate the performance, nutrient utilisation and energy metabolism of broiler chicks fed 8 different wheat samples, supplemented or not with xylanase. Seven-hundred sixty eight male broilers (1-day-old were distributed to 16 experimental treatments (6 replicates per treatment. The treatments were in a factorial arrangement with 8 different wheats and 2 levels of xylanase (0 or 16,000 BXU/kg. The predicted apparent metabolisable energy (AME of the wheat samples ranged from 13.0 to 13.9 MJ/kg and all diets were formulated to contain the same amount of wheat. Body weight gain (BWG and feed intake (FI were measured at 21 d, as was jejunal digesta viscosity, and feed conversion ratio (FCR calculated. On day 24, one representative bird per pen was selected to calculate whole body energetics. At 21 d, 3 chicks per replicate were randomly allocated to metabolism cages for energy and nutrient utilisation determinations, and were continued on the experimental diets until 24-d-old. No interactions were observed for any performance response variables, ileal nutrient utilisation or digesta viscosity. Xylanase improved BWG and reduced FCR and digesta viscosity (P < 0.05. Wheat influenced dry matter (DM utilisation and xylanase increased ileal digestible energy (P = 0.04. Xylanase also improved (P < 0.05 DM and nitrogen retention. Apparent metabolisable energy and AME corrected for nitrogen (AMEn were subject to an interaction whereby wheats 2 and 6, which returned the lowest AME and AMEn values, responded to xylanase supplementation and the remainder did not. Net energy for production and the efficiency of energy use for production were not influenced by xylanase, but were affected by wheat (P < 0.05. Despite the significant differences between wheats with regards to their nutrient utilisation and energy metabolism in birds, xylanase removed this variance and resulted in more homogeneous performance.

Optimization of xylanase production by Mucor indicus, Mucor hiemalis, and Rhizopus oryzae through solid state fermentation

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Sanaz Behnam

2016-03-01

Full Text Available Introduction: Xylan is the main hemicellulosic polymer in a number of lignocelluloses which can be hydrolyzed by xylanolytic enzymes. One of the main ways for enzymes production is solid state fermentation (SSF. The ability of three fungal strains (Mucor indicus, Mucor hiemalis, and Rhizopus oryzae for xylanase production on wheat bran by SSF was investigated. Materials and methods: The effects of cultivation temperature, medium moisture content, and cultivation time on the enzyme production were investigated. Experiments were designed with an orthogonal central composite design on three variables using response surface methodology (RSM. Analysis of variance was applied and the enzyme production was expressed with a mathematical equation as a function of the three factors. The optimum operating conditions for the enzyme production was obtained. Results: For xylanase production by M. indicus, M. hiemalis and R. oryzae the optimum temperatures were 40.0, 43.4 and 43.4ºC respectively. These values were 49.8, 54.2 and 71.8% for moisture percent and 51.3, 53.2 and 53.5 h for cultivation time. The highest enzyme activities per g of dry substrate (gds were 43.1, 43.8 and 25.9 U/gds for M. indicus, M. hiemalis and R. oryzae respectively. Discussion and conclusion: All the fungi were able to produce xylanase. Maximum xylanase production was predicted by M. indicus and M. hiemalis at similar optimum conditions, while R. oryzae produced relatively lower xylanase activity even at the best condition. 

Production of Sporotrichum thermophile xylanase by solid state fermentation utilizing deoiled Jatropha curcas seed cake and its application in xylooligosachharide synthesis.

Science.gov (United States)

Sadaf, Ayesha; Khare, S K

2014-02-01

De-oiled Jatropha curcas seed cake, a plentiful by-product of biodiesel industry was used as substrate for the production of a useful xylanase from Sporotrichum thermophile in solid state fermentation. Under the optimized conditions, 1025U xylanase/g (deoiled seed cake) was produced. The xylanase exhibited half life of 4h at 45°C and 71.44min at 50°C respectively. It was stable in a broad pH range of 7.0-11.0. Km and Vmax were 12.54mg/ml and 454.5U/ml/min respectively. S. thermophile xylanase is an endoxylanase free of exoxylanase activity, hence advantageous for xylan hydrolysis to produce xylooligosachharides. Hydrolysis of oat spelt xylan by S. thermophile xylanase yielded 73% xylotetraose, 15.4% xylotriose and 10% xylobiose. The S. thermophile endoxylanase thus seem potentially useful in the food industries. Copyright © 2013 Elsevier Ltd. All rights reserved.

Xylanase from Fusarium heterosporum: Properties and influence of ...

African Journals Online (AJOL)

Unioeste

2014-02-26

Feb 26, 2014 ... influence of thiol compounds on xylanase activity. Paulo Ricardo ... and the extraction of plant oil, coffee and starch (Ahmed ... of F. heterosporum on 5 g of various carbon sources ... brewing residue under solid-state fermentation (fungal strain and .... active within the acidic pH range of 4.5 to 5.5 and.

Comparison of kinetic characteristics of xylanases from Aspergillus ...

African Journals Online (AJOL)

Arabinoxylans are the predominant non-starch polysaccharides of the cell walls of wheat grain, and can contribute up to 3% of the total polysaccharide content of the flour. Endo-(1-4)-β-xylanase is able to hydrolyze the glycosidic bonds between two xylose units in the xylan backbone during baking process. The use of ...

High xylanase production by Trichoderma viride using pineapple ...

African Journals Online (AJOL)

SAM

2014-05-28

May 28, 2014 ... T. viride xylanase was stable at 40°C, showing the half-life (T1/2) value of ... Many studies have demonstrated that the pulp ... disposed in the environment without an adequate .... one-way analysis of variance and compared through the Tukey test, .... production by T. harzianum with wheat straw increases.

Production of Xylanase by Recombinant Bacillus subtilis DB104 Cultivated in Agroindustrial Waste Medium

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Is Helianti

2016-07-01

Full Text Available A recombinant Bacillus subtilis DB104 strain harbouring recombinant plasmid pSKE194 containing an Open Reading Frame (ORF of endoxylanase and its indigenous promoter from the wild-type B. subtilis AQ1 strain was constructed. This recombinant B. subtilis DB104 strain had higher endoxylanase activity than the nonrecombinant B. subtilis DB104 strain in standard media, such as Luria Bertani (LB and LB with xylan. The agroindustrial wastes corncobs and tofu liquid waste were chosen as cost-effective carbon and nitrogen sources, respectively, to test the economics of xylanase production using the recombinant B. subtilis DB104 at a larger scale. Submerged fermentation using a 4.5 L working volume fermentor with tofu liquid waste and 4% corncobs produced maximum xylanase activity of 1296 ± 1.2 U/mg (601.7 ± 0.6 U/mL after 48-hour fermentation at 37°C with 150 rpm agitation; this is more than twofold higher than the activity produced in an Erlenmeyer flask. This is the first report of high xylanase activity produced from recombinant B. subtilis using inexpensive medium. During fermentation, the xylanase degrades corncobs into xylooligosaccharides, showing its potential as an enzyme feed additive or in xylooligosaccharide production.

Heterologous expression of chaetomium thermophilum xylanase 11-a (ctx 11-a) gene

International Nuclear Information System (INIS)

Wajid, S.; Shahid, S.; Mukhtar, Z.; Mansoor, S.

2009-01-01

Chaetomium has a potential source of xylanase and cellulase enzymes, both of which are required in the treatment of fibre in the poultry feed. The titre of the enzymes needs to be enhanced by using recombinant DNA technology for fulfilling the requirement of the industries. Efforts are made to construct prokaryotic and eukaryotic expression cassettes that can be cloned under specific strong promoters i.e., T7 and AOX1, respectively, and the enhancer elements to get the maximum gene expression. In the present study BL21 E. coli and GS115 Pichia pastoris strains are used as model organisms to express the CtX 11-A gene in the presence of 1 mM IPTG and 100% methanol upto final concentration of 0.5. In case of BL21 expression, the maximum xylanase activity was observed after 1.5 h in the presence of 1% xylose, which was 2.302 U/ml and after 7 h in the presence of 0.5% lactose, was 1.708 U/ml. However, in Pichia pastoris the maximum production of xylanase was 2.904 and 0.006 U/ml as compared to control 0.484 and 0.06 U/ml, respectively. (author)

Polypeptides having xylanase activity and polynucleotides encoding same

Energy Technology Data Exchange (ETDEWEB)

Spodsberg, Nikolaj; Shaghasi, Tarana

2017-06-20

The present invention relates to polypeptides having xylanase activity, catalytic domains, and carbohydrate binding domains, and polynucleotides encoding the polypeptides, catalytic domains, and carbohydrate binding domains. The present invention also relates to nucleic acid constructs, vectors, and host cells comprising the polynucleotides as well as methods of producing and using the polypeptides, catalytic domains, and carbohydrate binding domains.

Evaluation of xylanases from Aspergillus niger and Trichoderma sp ...

African Journals Online (AJOL)

Despite being present in relatively low amounts, pentosans and hemicelluloses play an important role in dough rheology and bread properties. The aim of this work is to understand how the xylanases from Aspergillus niger and Trichoderma sp. influence dough rheology, such as elasticity, extensibility, strength and stability.

Molecular Dynamics Approach in Designing Thermostable Aspergillus niger Xylanase

Science.gov (United States)

Malau, N. D.; Sianturi, M.

2017-03-01

Molecular dynamics methods we have applied as a tool in designing thermostable Aspergillus niger Xylanase, by examining Root Mean Square Deviation (RMSD) and The Stability of the Secondary Structure of enzymes structure at its optimum temperature and compare with its high temperature behavior. As RMSD represents structural fluctuation at a particular temperature, a better understanding of this factor will suggest approaches to bioengineer these enzymes to enhance their thermostability. In this work molecular dynamic simulations of Aspergillus niger xylanase (ANX) have been carried at 400K (optimum catalytic temperature) for 2.5 ns and 500K (ANX reported inactive temperature) for 2.5 ns. Analysis have shown that the Root Mean Square Deviation (RMSD) significant increase at higher temperatures compared at optimum temperature and some of the secondary structures of ANX that have been damaged at high temperature. Structural analysis revealed that the fluctuations of the α-helix and β-sheet regions are larger at higher temperatures compared to the fluctuations at optimum temperature.

Enzymatic saccharification of seaweeds into fermentable sugars by xylanase from marine Bacillus sp. strain BT21.

Science.gov (United States)

Parab, Pankaj; Khandeparker, Rakhee; Amberkar, Ujwala; Khodse, Vishwas

2017-10-01

Enzymatic hydrolysis of seaweed biomass was studied using xylanase produced from marine bacteria Bacillus sp. strain BT21 through solid-state fermentation of wheat bran. Three types of seaweeds, Ahnfeltia plicata , Padina tetrastromatica and Ulva lactuca , were selected as representatives of red, brown, and green seaweeds, respectively. Seaweed biomass was pretreated with hot water. The efficiency of pretreated biomass to release reducing sugar by the action of xylanase as well as the type of monosaccharide released during enzyme saccharification of seaweed biomass was studied. It was seen that pretreated biomass of seaweed A. plicata, U. lactuca , and P. tetrastroma , at 121 °C for 45 min, followed by incubation with 50 IU xylanase released reducing sugars of 233 ± 5.3, 100 ± 6.1 and 73.3 ± 4.1 µg/mg of seaweed biomass, respectively. Gas chromatography analysis illustrated the release of xylose, glucose, and mannose during the treatment process. Hot water pre-treatment process enhanced enzymatic conversion of biomass into sugars. This study revealed the important role of xylanase in saccharification of seaweed, a promising feedstock for third-generation bioethanol production.

Optimization of moistening solution concentration on xylanase activity in solid state fermentation from oil palm empty fruit bunches

Science.gov (United States)

Mardawati, Efri; Parlan; Rialita, Tita; Nurhadi, Bambang

2018-03-01

Xylanase is an enzyme used in the industrial world, including food industry. Xylanase can be utilized as a 1,4-β-xylosidic endo-hydrolysis catalyst of xylanase, a hemicellulose component for obtaining a xylose monomer. This study aims to determine the optimum concentration of the fermentation medium using Response Surface Method (RSM) in the production of xylanase enzyme from oil palm empty fruit bunches (OPEFB) through solid state fermentation process. The variables varied in this study used factor A (ammonium sulphate concentration 1.0-2.0 g/L), B (concentration of potassium dihydrogen phosphate 1.5-2.5 g/L) and C (urea concentration 0.2 – 0.5 g/L). The data was analysed by using Design Expert version 10.0.1.0 especially CCD with total 17 running including 3 times replicated of canter point. Trichoderma viride was used for the process production of xylanase enzyme. The ratio between substrate and moistening solution used was 0.63 g / mL with temperature of 32.80C, 60 h incubation time. The analysis of enzyme activity was done by DNS method with 1% xylan as substrate. Analysis of protein content in enzyme was done by Bradford method. The optimum of moistening solution concentration in this fermentation was obtained. They are, the ammonium sulphate concentration of 1.5 g/L, potassium dihydrogen phosphate 2.0 g/L and urea 0.35 g/L with activity of 684.70 U/mL, specific activity enzyme xylanase 6261.58 U/mg, protein content 0.1093 U/mg, the model was validated using experiment design with perfect reliability value 0.96.

Engineering improved thermostability of the GH11 xylanase from Neocallimastix patriciarum via computational library design.

Science.gov (United States)

Bu, Yifan; Cui, Yinglu; Peng, Ying; Hu, Meirong; Tian, Yu'e; Tao, Yong; Wu, Bian

2018-04-01

Xylanases, which cleave the β-1,4-glycosidic bond between xylose residues to release xylooligosaccharides (XOS), are widely used as food additives, animal feeds, and pulp bleaching agents. However, the thermally unstable nature of xylanases would hamper their industrial application. In this study, we used in silico design in a glycoside hydrolase family (GH) 11 xylanase to stabilize the enzyme. A combination of the best mutations increased the apparent melting temperature by 14 °C and significantly enhanced thermostability and thermoactivation. The variant also showed an upward-shifted optimal temperature for catalysis without compromising its activity at low temperatures. Moreover, a 10-fold higher XOS production yield was obtained at 70 °C, which compensated the low yield obtained with the wild-type enzyme. Collectively, the variant constructed by the computational strategy can be used as an efficient biocatalyst for XOS production at industrially viable conditions.

(Trametes sp.) in the production of cellulase and xylanase

African Journals Online (AJOL)

Nanda

2016-05-18

May 18, 2016 ... in solid-sate fermentation (SSF), in this work, the production of cellulase and xylanase by the fungus ... sugars can be converted to ethanol, lactic acid and ... substances; clarification of juices and wines; improving ..... SSF processes has a marked effect on growth kinetics, ..... Overview of applied solid-state.

Characterization of Two Endo-β-1, 4-Xylanases from Myceliophthora thermophila and Their Saccharification Efficiencies, Synergistic with Commercial Cellulase

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Abdul Basit

2018-02-01

Full Text Available The xylanases with high specific activity and resistance to harsh conditions are of high practical value for biomass utilization. In the present study, two new GH11 xylanase genes, MYCTH_56237 and MYCTH_49824, have been cloned from thermophilic fungus Myceliophthora thermophila and expressed in Pichia pastoris. The specific activities of purified xylanases reach approximately 1,533.7 and 1,412.5 U/mg, respectively. Based on multiple template-based homology modeling, the structures of their catalytic domains are predicted. Enzyme activity was more effective in 7.5 L fermentor, yielding 2,010.4 and 2,004.2 U/mL, respectively. Both enzymes exhibit optimal activity at 60°C with pH of 6.0 and 7.0, respectively. Their activities are not affected by EDTA and an array of metal ions. The kinetic constants have been determined for MYCTH_56237 (Km = 8.80 mg/mL, Vmax = 2,380 U/mg and MYCTH_49824 (Km = 5.67 mg/mL, Vmax = 1,750 U/mg. More importantly, both xylanases significantly cooperate with the commercial cellulase Celluclast 1.5 L in terms of the saccharification efficiency. All these biochemical properties of the xylanases offer practical potential for future applications.

Comparison of several ethanol productions using xylanase, inorganic salts, surfactant

Science.gov (United States)

Wu, Yan; Lu, Jie; Yang, Rui-feng; Song, Wen-jing; Li, Hai-ming; Wang, Hai-song; Zhou, Jing-hui

2017-03-01

Liquid hot water (LHW) pretreatment is an effective and environmentally friendly method to produce bioethanol with lignocellulosic materials. Corn stover was pretreated with liquid hot water (LHW) and then subjected to semi-simultaneous saccharification and fermentation (S-SSF) to obtain high ethanol concentration and yield. The present study aimed to confirm the effect of several additives on the fermentation digestibility of unwashed WIS of corn stover pretreated with LHW. So we also investigated the process, such as enzyme addition, inorganic salts, surfactant and different loading Triton. Results show that high ethanol concentration is necessary to add xylanase in the stage of saccharification. The ethanol concentration increased mainly with magnesium ion on fermentation. Comparing with Tween 80, Span 80 and Polyethylene glycol, Triton is the best surfactant. In contrast to using xylanase and Triton respectively, optimization can make up the lack of stamina and improve effect of single inorganic salts.

Suitable conditions for xylanases activities from Bacillus sp. GA2(1 and Bacillus sp. GA1(6 and their properties for agricultural residues hydrolysis

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Sudathip Chantorn

2016-04-01

Full Text Available Bacillus sp. GA2(1 and Bacillus sp. GA1(6 were isolated from soybean field in Khon Kaen province, Thailand. Crude enzymes from both isolates showed the activities of cellulase, xylanase, and mannanase at 37°C for 24 h. The highest xylanase activities of Bacillus sp. GA2(1 and Bacillus sp. GA1(6 were 1.58±0.25 and 0.82±0.16 U/ml, respectively. The relative xylanase activities from both strains were more than 60% at pH 5.0 to 8.0. The optimum temperature of xylanases was 50°C in both strains. The residual xylanase activities from both strains were more than 70% at 60°C for 60 min. Five agricultural wastes (AWs, namely coffee residue, soybean meal, potato peel, sugarcane bagasse, and corn cobs, were used as substrates for hydrolysis properties. The highest reducing sugar content of 101±1.32 µg/ml was obtained from soybean meal hydrolysate produced by Bacillus sp. GA2(1 xylanase.

Optimization of Xylanase production from Penicillium sp.WX-Z1 by a two-step statistical strategy: Plackett-Burman and Box-Behnken experimental design.

Science.gov (United States)

Cui, Fengjie; Zhao, Liming

2012-01-01

The objective of the study was to optimize the nutrition sources in a culture medium for the production of xylanase from Penicillium sp.WX-Z1 using Plackett-Burman design and Box-Behnken design. The Plackett-Burman multifactorial design was first employed to screen the important nutrient sources in the medium for xylanase production by Penicillium sp.WX-Z1 and subsequent use of the response surface methodology (RSM) was further optimized for xylanase production by Box-Behnken design. The important nutrient sources in the culture medium, identified by the initial screening method of Placket-Burman, were wheat bran, yeast extract, NaNO(3), MgSO(4), and CaCl(2). The optimal amounts (in g/L) for maximum production of xylanase were: wheat bran, 32.8; yeast extract, 1.02; NaNO(3), 12.71; MgSO(4), 0.96; and CaCl(2), 1.04. Using this statistical experimental design, the xylanase production under optimal condition reached 46.50 U/mL and an increase in xylanase activity of 1.34-fold was obtained compared with the original medium for fermentation carried out in a 30-L bioreactor.

Optimisation of amylase and xylanase addition in dependance of white flour amylase activity

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Lončar Davor M.

2016-01-01

Full Text Available In this study the effect of different quantities of added amylase to white wheat flours characterized with different activities of naturally existing amylases is tested. Response surface methodology is chosen to test the effects of main applied technological parameters on bread quality responses. Independent variables are chosen to be: quantity of added amylase and bulk fermentation time, while analysed responses are: specific volume, grain structure, bulk fermentation. Bread quality responses are statistically significant, while predicted and observed responses correspond very well, which allows good prediction of bread quality parameters based on applied technological parameters and flour characteristics. Score analysis shows that optimum quantity of amylase addition regarding bread quality depends on the activity of naturally existing amylases. Optimal quantity of added xylanase in bread samples made from both flour types is 0.004%. Xylanase improved properties of white wheat bread and higher effect is experienced with flour that has more active naturally existing amylases. Addition of amylase has statistically significantly increased a* values of crust. Addition of xylanase has statistically significantly decreased values of b* in comparison to the respective bread sample with only added amylase.

Ultrasounds pretreatment of olive pomace to improve xylanase and cellulase production by solid-state fermentation.

Science.gov (United States)

Leite, Paulina; Salgado, José Manuel; Venâncio, Armando; Domínguez, José Manuel; Belo, Isabel

2016-08-01

Olive mills generate a large amount of waste that can be revaluated. This work aim to improve the production lignocellulolytic enzymes by solid-state fermentation using ultrasounds pretreated olive mill wastes. The composition of olive mill wastes (crude and exhausted olive pomace) was compared and several physicochemical characteristics were significantly different. The use of both wastes in SSF was evaluated and a screening of fungi for xylanase and cellulase production was carried out. After screening, the use of exhausted olive pomace and Aspergillus niger led to the highest enzyme activities, so that they were used in the study of ultrasounds pre-treatment. The results showed that the sonication led to a 3-fold increase of xylanase activity and a decrease of cellulase activity. Moreover, the liquid fraction obtained from ultrasounds treatment was used to adjust the moisture of solid and a positive effect on xylanase (3.6-fold increase) and cellulase (1.2-fold increase) production was obtained. Copyright © 2016 Elsevier Ltd. All rights reserved.

EFFECT OF XYLANASE ADDED TO A RYE-BASED DIET ON NUTRIENT UTILIZATION IN PIGS

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Jaroslav Heger

2012-02-01

Full Text Available The effect of enzyme xylanase derived from Trichoderma longibrachiatum supplemented to a rye-based diet on apparent ileal digestibility of amino acids and non-starch polysaccharides constituting sugars was studied. Enzymes supplementation at 200 mg.kg−1 increased (P˂0.05 the digestibility of total amino acids from 67.1 to 70.8. When the dietary concentration of enzyme increased from 0 to 100 mg.kg-1, the ileal digestibility of the NSP constituents gradually increased as well. No further increase was observed with the supplementation level of 200 mg.kg-1. The improvement in the digestibility of arabinose and xylose (685%, P˂0.05 was much higher in comparison with remaining sugars (110%, P˂0.05. The apparent ileal digestibility of galactose was positively influenced by xylanase but it remained negative in all dietary treatments, presumably due to the high concentration of galactose in endogenous secretions. It is concluded that xylanase effectively degrades non-starch polysaccharides in upper digestive tract and marginally improves amino acid availability in young pigs.

Xylanase production by a thermo-tolerant Bacillus species under solid-state and submerged fermentation

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Uma Gupta

2009-12-01

Full Text Available Effects of xylose on xylanase production by a thermophilic Bacillus sp showed diverse patterns on corn cob (CC and wheat bran (WB as sole carbon sources in solid- state fermentation (SSF and submerged fermentation (SmF. Supplementation of these media with either mineral salt solution (MSS or yeast extract peptone (YEP also exerted variable effects. While under SSF, xylose stimulated xylanase synthesis by 44.01%, on wheat bran supplemented with MSS, it decreased the enzyme activity by 12.89% with YEP supplementation. In SmF, however the enzyme synthesis was stimulated by xylose on supplementation with both MSS and YEP by 41.38% and 27.47%, respectively. On corn cob under SSF, xylose repression was significant both with MSS (26.92% and YEP (23.90% supplementation. Repression by xylose also took place on corn cob and YEP (19.69% under SmF, while significant stimulation (28.55% was observed by MSS supplementation. The possible role of media composition and fermentation conditions in the regulation of xylanase synthesis by xylose is discussed.

Enzymic hydrolysis of xylans. I. A high xylanase and beta-xylosidase producing strain of Aspergillus niger

Energy Technology Data Exchange (ETDEWEB)

Conrad, D.

1981-01-01

Aspergillus niger, strain 110.42 (CBS) was selected as a producer of high xylanolytic activities. The time course of xylanase and beta-xylosidase production as well as the effect of pH and temperature on the activity of these enzymes were studied. High-performance liquid chromatography analysis of the enzymic degradation of arabinoxylan showed a nearly complete conversion to pentose sugars. Aspects of using crude xylanase preparations for enzymic saccharification of xylans are discussed.

Improvement for enhanced xylanase production by Cellulosimicrobium cellulans CKMX1 using central composite design of response surface methodology.

Science.gov (United States)

Walia, Abhishek; Mehta, Preeti; Guleria, Shiwani; Shirkot, Chand Karan

2015-12-01

The effects of yeast extract (X 1 ), NH 4 NO 3 (X 2 ), peptone (X 3 ), urea (X 4 ), CMC (X 5 ), Tween 20 (X 6 ), MgSO 4 (X 7 ), and CaCO 3 (X 8 ) on production of xylanase from Cellulosimicrobium cellulans CKMX1 were optimized by statistical analysis using response surface methodology (RSM). The RSM was used to optimize xylanase production by implementing the Central composite design. Statistical analysis of the results showed that the linear, interaction and quadric terms of these variables had significant effects. However, only the linear effect of X 4 , X 5 , interaction effect of X 1 X 7 , X 1 X 8 , X 2 X 3 , X 2 X 8 , X 3 X 6 , X 3 X 8 , X 4 X 6 , X 4 X 7 , X 5 X 7 , X 5 X 8 and quadratic effect of X 3 2 , X 5 2 and X 7 2 found to be insignificant terms in the quadratic model and had no response at significant level. The minimum and maximum xylanase production obtained was 331.50 U/g DBP and 1027.65 U/g DBP, respectively. The highest xylanase activity was obtained from Run No. 30, which consisted of yeast extract (X 1 ), 1.00 g (%); NH 4 NO 3 (X 2 ), 0.20 g (%); peptone (X 3 ), 1.00 g (%); urea (X 4 ), 10 mg (%); CMC (X 5 ), 1.00 g (%); Tween 20 (X 6 ), 0.02 mL (%); CaCO 3 (X 7 ), 0.50 g (%) and MgSO 4 (X 8 ), 9.0 g (%). The optimization resulted in 3.1-fold increase of xylanase production, compared with the lowest xylanase production of 331.50 U/g DBP after 72 h of incubation in stationary flask experiment. Application of cellulase-free xylanase in pulp biobleaching from C. cellulans CKMX1 under C-E P -D sequence has been shown to bring about a 12.5 % reduction of chlorine, decrease of 0.8 kappa points (40 %), and gain in brightness was 1.42 % ISO points in 0.5 % enzyme treated pulp as compared to control.

Optimization of Xylanase Production through Response Surface Methodology by Fusarium sp. BVKT R2 Isolated from forest soil and its applications in saccharification

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Ramanjaneyulu Golla

2016-09-01

Full Text Available AbstractXylanses are hydrolytic enzymes with wide applications in several industries like biofuels, paper and pulp, deinking, food and feed. The present study was aimed at hitting at high yield xylanase producing fungi from natural resources. Two highest xylanase producing fungal isolates - Q12 and L1were picked from collection of 450 fungal cultures for the utilization of xylan. These fungal isolates - Q12 and L1 were identified basing on ITS gene sequencing analysis as Fusarium sp. BVKT R2 (KT119615 and Fusarium strain BRR R6 (KT119619, respectively with construction of phylogenetic trees. Fusarium sp. BVKT R2 was further optimized for maximum xylanase production and the interaction effects between variables on production of xylanase were studied through response surface methodology. The optimal conditions for maximal production of xylanase were sorbitol 1.5%, yeast extract 1.5%, pH of 5.0, Temperature of 32.5ºC, and agitation of 175 rpm. Under optimal conditions, the yields of xylanase production by Fusarium sp. BVKT R2 was as high as 4560 U/ml in SmF. Incubation of different lignocellulosic biomasses with crude enzyme of Fusarium sp. BVKT R2 at 37°C for 72 h could achieve about 45% saccharification. The results suggest that Fusarium sp. BVKT R2 has potential applications in saccharification process of biomass.Key words: Fusarium sp., Optimization, Response Surface Methodology, Saccharification, Submerged fermentation, Xylanase

Improvement of the catalytic efficiency of a hyperthermophilic xylanase from Bispora sp. MEY-1.

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Xiaoyu Wang

Full Text Available Extremophilic xylanases have attracted great scientific and industrial interest. In this study, a GH10 xylanase-encoding gene, Xyl10E, was cloned from Bispora sp. MEY-1 and expressed in Pichia pastoris GS115. Deduced Xyl10E shares the highest identities of 62% and 57% with characterized family GH10 xylanases from Talaromyces leycettanus and Penicillium canescens (structure 4F8X, respectively. Xyl10E was most active at 93 to 95°C and pH 4.0, retained more than 75% or 48% of the initial activity when heated at 80°C or 90°C for 30 min, respectively, and hardly lost activity at pH 1.0 to 7.0, but was completely inhibited by SDS. Two residues, A160 and A161, located on loop 4, were identified to play roles in catalysis. Mutants A160D/E demonstrated higher affinity to substrate with lower Km values, while mutants A161D/E mainly displayed elevated Vmax values. All of these mutants had significantly improved catalytic efficiency. According to the molecular dynamics simulation, the mutation of A160E was able to affect the important substrate binding site Y204 and then improve the substrate affinity, and the mutation of A161D was capable of forming a hydrogen bond with the substrate to promote the substrate binding or accelerate the product release. This study introduces a highly thermophilic fungal xylanase and reveals the importance of loop 4 for catalytic efficiency.

One-step purification and characterization of cellulase-free xylanase produced by alkalophilic Bacillus subtilis ash

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Ashwani Sanghi

2010-06-01

Full Text Available The present study describes the one-step purification and characterization of an extracellular cellulase-free xylanase from a newly isolated alkalophilic and moderately thermophilic strain of Bacillus subtilis ASH. Xylanase was purified to homogeneity by 10.5-fold with ~43% recovery using ion-exchange chromatography through CM-Sephadex C-50. The purified enzyme revealed a single band on SDS-PAGE gel with a molecular mass of 23 kDa. It showed an optimum pH at 7.0 and was stable over the pH range 6.0-9.0. The optimum temperature for enzyme activity was 55 ºC. The purified xylanase did not lose any activity up to 45 ºC, however, it retained 80% and 51% of its activity after pre-incubation at 55 ºC and 60 ºC, respectively. The enzyme obeyed Michaelis-Menton kinetics towards birch wood xylan with apparent Km 3.33 mg/ml and Vmax 100 IU/ml. The enzyme was strongly inhibited by Hg2+ and Cu2+ while enhanced by Co2+ and Mn2+. The purified enzyme could be stored at 4 ºC for six weeks without any loss of catalytic activity. The faster and economical purification of the cellulase-free xylanase from B. subtilis ASH by one-step procedure together with its appreciable stability at high temperature and alkaline pH makes it potentially effective for industrial applications.

Interaction studies of resistomycin from Streptomyces aurantiacus AAA5 with calf thymus DNA and bovine serum albumin

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Vijayabharathi, R.; Sathyadevi, P.; Krishnamoorthy, P.; Senthilraja, D.; Brunthadevi, P.; Sathyabama, S.; Priyadarisini, V. Brindha

2012-04-01

Resistomycin, a secondary metabolite produced by Streptomyces aurantiacus AAA5. The binding interaction of resistomycin with calf thymus DNA (CT DNA) and bovine serum albumin (BSA) was investigated by spectrophotometry, spectrofluorimetry, circular dichroism (CD) and synchronous fluorescence techniques under physiological conditions in vitro. Absorption spectral studies along with the fluorescence competition with ethidium bromide measurements and circular dichroism clearly suggest that the resistomycin bind with CT DNA relatively strong via groove binding. BSA interaction results revealed that the drug was found to quench the fluorescence intensity of the protein through a static quenching mechanism. The number of binding sites 'n' and apparent binding constant 'K' calculated according to the Scatchard equation exhibit a good binding property to bovine serum albumin protein. In addition, the results observed from synchronous fluorescence measurements clearly demonstrate the occurrence of conformational changes of BSA upon addition of the test compound.

Effect of combined xylanase and phytase on growth performance, apparent total tract digestibility, and carcass characteristics in growing pigs fed corn-based diets containing high-fiber coproducts.

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Jang, Y D; Wilcock, P; Boyd, R D; Lindemann, M D

2017-09-01

Phytate has been shown to be an antinutrient, and the feeding of high levels of phytase can break down phytate to improve nutrient utilization and pig performance. Dietary xylanase targets arabinoxylan breakdown, thereby improving energy utilization in pigs. However, the effects of simultaneous supplementation have not been clearly determined. Crossbred pigs ( = 45; mean initial weight, 26.4 ± 0.2 kg) were allotted to 1 of 9 treatments to evaluate the effects of both xylanase (endo-1,4-β xylanase [EC 3.2.1.8]) and phytase (6-phytase [EC 3.1.3.26]) supplementation as follows: 1) positive control (PC), a corn-soybean meal-based diet with 15% corn distillers dried grains with solubles, 15% wheat middlings, and 13% corn germ meal; 2) negative control (NC), ME was reduced by 103 kcal/kg from the PC diet by replacement of fat with corn starch; 3) NC + phytase (500 phytase units (FTU)/kg diet); 4) NC + phytase (1,000 FTU/kg diet); 5) NC + phytase (2,000 FTU/kg diet); 6) NC + xylanase (24,000 xylanase units [BXU]/kg diet); 7) NC + phytase (500 FTU/kg diet) + xylanase (24,000 BXU/kg diet); 8) NC + phytase (1,000 FTU/kg diet) + xylanase (24,000 BXU/kg diet); and 9) NC + phytase (2,000 FTU/kg diet) + xylanase (24,000 BXU/kg diet). All diets were formulated to meet nutrient requirements before phytase and xylanase addition to the diets. There were no significant interactions between xylanase and phytase supplementation on growth performance, carcass characteristics, and apparent total tract digestibility (ATTD). The ADG ( phytase level increased. The ATTD of P increased as phytase supplementation level increased ( phytase level increased. Estimated carcass lean percentage and lean gain increased ( phytase level increased. Xylanase supplementation had no effect on growth performance, ATTD, and carcass characteristics. The results demonstrated an improved nutrient digestibility, performance, and carcass response to phytase supplementation beyond P provision because all diets

Effect of Aspergillus niger xylanase on dough characteristics and bread quality attributes.

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Ahmad, Zulfiqar; Butt, Masood Sadiq; Ahmed, Anwaar; Riaz, Muhammad; Sabir, Syed Mubashar; Farooq, Umar; Rehman, Fazal Ur

2014-10-01

The present study was conducted to investigate the impact of various treatments of xylanase produced by Aspergillus niger applied in bread making processes like during tempering of wheat kernels and dough mixing on the dough quality characteristics i.e. dryness, stiffness, elasticity, extensibility, coherency and bread quality parameters i.e. volume, specific volume, density, moisture retention and sensory attributes. Different doses (200, 400, 600, 800 and 1,000 IU) of purified enzyme were applied to 1 kg of wheat grains during tempering and 1 kg of flour (straight grade flour) during mixing of dough in parallel. The samples of wheat kernels were agitated at different intervals for uniformity in tempering. After milling and dough making of both types of flour (having enzyme treatment during tempering and flour mixing) showed improved dough characteristics but the improvement was more prominent in the samples receiving enzyme treatment during tempering. Moreover, xylanase decreased dryness and stiffness of the dough whereas, resulted in increased elasticity, extensibility and coherency and increase in volume & decrease in bread density. Xylanase treatments also resulted in higher moisture retention and improvement of sensory attributes of bread. From the results, it is concluded that dough characteristics and bread quality improved significantly in response to enzyme treatments during tempering as compared to application during mixing.

Catalytic performance of corn stover hydrolysis by a new isolate Penicillium sp. ECU0913 producing both cellulase and xylanase.

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Shi, Qian-Qian; Sun, Jie; Yu, Hui-Lei; Li, Chun-Xiu; Bao, Jie; Xu, Jian-He

2011-07-01

A fungal strain, marked as ECU0913, producing high activities of both cellulase and xylanase was newly isolated from soil sample collected near decaying straw and identified as Penicillium sp. based on internal transcribed spacer sequence homology. The cultivation of this fungus produced both cellulase (2.40 FPU/ml) and xylanase (241 IU/ml) on a stepwisely optimized medium at 30 °C for 144 h. The cellulase and xylanase from Penicillium sp. ECU0913 was stable at an ambient temperature with half-lives of 28 and 12 days, respectively. Addition of 3 M sorbitol greatly improved the thermostability of the two enzymes, with half-lives increased by 2.3 and 188-folds, respectively. Catalytic performance of the Penicillium cellulase and xylanase was evaluated by the hydrolysis of corn stover pretreated by steam explosion. With an enzyme dosage of 50 FPU/g dry substrate, the conversions of cellulose and hemicellulose reached 77.2% and 47.5%, respectively, without adding any accessory enzyme.

Influence of xylanase addition on the characteristics of loaf bread prepared with white flour or whole grain wheat flour

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Leandra Zafalon Jaekel

2012-12-01

Full Text Available The aim of this study was to verify the influence of the addition of the enzyme xylanase (four concentrations: 0, 4, 8, and 12 g.100 kg-1 flour on the characteristics of loaf bread made with white wheat flour or whole grain wheat flour. Breads made from white flour and added with xylanase had higher specific volumes than those of the control sample (no enzyme; however, the specific volume did not differ significantly (p < 0.05 among the breads with different enzyme concentrations. All formulations made from whole grain wheat flour and added with xylanase also had specific volumes significantly higher than those of the control sample, and the highest value was found for the 8 g xylanase.100 kg-1 flour formulation. With respect to moisture content, the formulations with different enzyme concentrations showed small significant differences when compared to the control samples. In general, breads made with the addition of 8 g enzyme.100 kg-1 flour had the lowest firmness values, thus presenting the best technological characteristics.

Constitutive expression of the xylanase inhibitor TAXI-III delays Fusarium head blight symptoms in durum wheat transgenic plants.

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Moscetti, Ilaria; Tundo, Silvio; Janni, Michela; Sella, Luca; Gazzetti, Katia; Tauzin, Alexandra; Giardina, Thierry; Masci, Stefania; Favaron, Francesco; D'Ovidio, Renato

2013-12-01

Cereals contain xylanase inhibitor (XI) proteins which inhibit microbial xylanases and are considered part of the defense mechanisms to counteract microbial pathogens. Nevertheless, in planta evidence for this role has not been reported yet. Therefore, we produced a number of transgenic plants constitutively overexpressing TAXI-III, a member of the TAXI type XI that is induced by pathogen infection. Results showed that TAXI-III endows the transgenic wheat with new inhibition capacities. We also showed that TAXI-III is correctly secreted into the apoplast and possesses the expected inhibition parameters against microbial xylanases. The new inhibition properties of the transgenic plants correlate with a significant delay of Fusarium head blight disease symptoms caused by Fusarium graminearum but do not significantly influence leaf spot symptoms caused by Bipolaris sorokiniana. We showed that this contrasting result can be due to the different capacity of TAXI-III to inhibit the xylanase activity of these two fungal pathogens. These results provide, for the first time, clear evidence in planta that XI are involved in plant defense against fungal pathogens and show the potential to manipulate TAXI-III accumulation to improve wheat resistance against F. graminearum.

The Influence of Xylanase Supplementation on Dough Rheology Concerning its Consistograph Parameters

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Rodica Chereji

2010-05-01

Full Text Available In this study we determined the influence of xylanase supplementation on dough rheology concerning its consistograph parameters: maximum pressure (Pr max, (mb and water absorption (Wa, %. The consistograph analyses were conducted at constant hydration and consistency of 500UF. Determinations were made on 4 types of flour and optimal enzyme dosages were determined. Then we added the optimal enzyme dose for each type of flour as follows: F1, F2, F3, F4: P1-8100U.FXU/100kg flour, P2-16200U.FXU/100kg flour, P3-24300U.FXU/100kg flour. Fungal xylanase used in these concentrations led to the improvement of bread quality properties: finer texture of the crumb, extending freshness of bread, improving the colour and flavour, improving the slicing ability.

The influence of sorbitol on the production of cellulases and xylanases in an airlift bioreactor.

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Ritter, Carla Eliana Todero; Fontana, Roselei Claudete; Camassola, Marli; da Silveira, Maurício Moura; Dillon, Aldo José Pinheiro

2013-11-01

The production of cellulases and xylanases by Penicillium echinulatum in an airlift bioreactor was evaluated. In batch production, we tested media with isolated or associated cellulose and sorbitol. In fed-batch production, we tested cellulose addition at two different times, 30 h and 48 h. Higher liquid circulation velocities in the downcomer were observed in sorbitol 10 g L(-1) medium. In batch production, higher FPA (filter paper activity) and endoglucanase activities were obtained with cellulose (7.5 g L(-1)) and sorbitol (2.5 g L(-1)), 1.0 U mL(-1) (120 h) and 6.4 U m L(-1) (100 h), respectively. For xylanases, the best production condition was cellulose 10 g L(-1), which achieved 5.5 U mL(-1) in 64 h. The fed-batch process was favorable for obtaining xylanases, but not for FPA and endoglucanases, suggesting that in the case of cellulases, the inducer must be added early in the process. Copyright © 2013 Elsevier Ltd. All rights reserved.

Homologue expression of a fungal endo-1,4-β-D- xylanase using ...

African Journals Online (AJOL)

Jane

2011-03-07

Mar 7, 2011 ... Hemicellulose is the second source of renewable organic carbon on earth, with a high potential for the recovery of ... SSF, solid-state fermentation; XE, xylanase extract. .... Active fractions were pooled, concentrated and.

Concurrent production of cellulase and xylanase from Trichoderma reesei NCIM 1186: enhancement of production by desirability-based multi-objective method.

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Jampala, Preethi; Tadikamalla, Satish; Preethi, M; Ramanujam, Swathy; Uppuluri, Kiran Babu

2017-05-01

Application of multiple response optimizations using desirability function in the production of microbial metabolites improves economy and efficiency. Concurrent production of cellulase and xylanase in Trichoderma reesei NCIM 1186 using an agricultural weed, Prosopis juliflora pods, was studied. The main aim of the study was to optimize significant medium nutrient parameters for maximization of cellulase and xylanase by multi-objective optimization strategy using biomass. Process parameters such as the nutrient concentrations (pods, sucrose, and yeast extract) and pH were investigated to improve cellulase and xylanase activities by one factor at a time approach, single response optimization and multi-objective optimization. At the corresponding optimized process parameters in single response optimization, the maximum cellulase activity observed was 3055.65 U/L where xylanase highest activity was 422.16 U/L. Similarly, the maximum xylanase activity, 444.94 U/L, was observed with the highest cellulase activity of 2804.40 U/L. The multi-objective optimization finds a tradeoff between the two objectives and optimal activity values in between the single-objective optima were achieved, 3033.74 and 439.13 U/L for cellulase and xylanase, respectively.

Enhancement of Cellulase and Xylanase Production Using pH-Shift and Dissolved Oxygen Control Strategy with Streptomyces griseorubens JSD-1.

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Zhang, Dan; Luo, Yanqing; Chu, Shaohua; Zhi, Yuee; Wang, Bin; Zhou, Pei

2016-01-01

In this study, the production of cellulase and xylanase by Streptomyces griseorubens JSD-1 was improved by integrating the pH-shift and dissolved oxygen (DO)-constant control strategies. The pH-shift control strategy was carried out by analyzing the specific cell growth rate (μ) and specific enzyme formation rate (Q p) of S. griseorubens JSD-1. The pH was controlled at 8.0 during the first 48 h to maintain high cell growth, which then shifted to 7.5 after 48 h to improve the production of cellulase and xylanase. Using this method, the maximum activities of cellulase, xylanase, and filter paper enzyme (FPase) increased by 47.9, 29.5, and 113.6 %, respectively, compared to that obtained without pH control. On the basis of pH-shift control, the influence of DO concentrations on biomass and enzyme production was further investigated. The maximum production of cellulase, xylanase, and FPase reached 114.38 ± 0.96 U mL(-1), 330.57 ± 2.54 U mL(-1), and 40.11 ± 0.38 U mL(-1), which were about 1.6-fold, 0.6-fold, and 3.2-fold higher than that of neutral pH without DO control conditions. These results supplied a functional approach for improving cellulase and xylanase production.

Molecular Cloning and Sequencing of AlkalophilicCellulosimicrobium cellulans CKMX1 Xylanase Gene Isolated from Mushroom Compost and Characterization of the Gene Product

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Abhishek Walia

2015-12-01

Full Text Available ABSTRACT A xylanolytic bacterium was isolated from mushroom compost by using enrichment technique. Results from the metabolic fingerprinting, whole-cell fatty acids methyl ester analysis and 16S rDNA sequencing suggested the bacterium to be Cellulosimicrobium cellulans CKMX1. Due to the xylanolytic activity of this bacterium, isolation and characterization of the xylanase gene were attempted. A distinct fragment of about 1671 bp was successfully amplified using PCR and cloned into Escherichia coli DH5α. A BLAST search confirmed that the DNA sequence from the amplified fragment was endo-1, 4-beta-xylanase, which was a member of glycoside hydrolase family 11. It showed 98% homology withCellulosimicrobium sp. xylanase gene (Accession no. FJ859907.1 reported from the gut of Eisenia fetida in Korea. In silicophysico-chemical characterization of amino acid sequence of xylanase showed an open reading frame encoding a 556 amino acid sequence with a molecular weight of 58 kDa and theoretical isolectric point (pI of 4.46 was computed using Expasy's ProtParam server. Secondary and homology based 3D structure of xylanase was analysed using SOPMA and Swiss-Prot software.

Kinetics and substrate selectivity of a Triticum aestivum xylanase inhibitor (TAXI) resistant D11F/R122D variant of Bacillus subtilis XynA xylanase

DEFF Research Database (Denmark)

Rasmussen, Louise Enggaard; Sørensen, Jens F.; Meyer, Anne S.

2010-01-01

This study examined the kinetics and substrate selectivity of a GH11 Bacillus subtilis XynA xylanase (BsX) sensitive to inhibition by TAXI and an engineered variant, which is much less inhibited by TAXI (BsX(mut)). The main purpose of the work was to elucidate any influence of the structural point...

Xylanase production by Trichoderma longibrachiatum

Energy Technology Data Exchange (ETDEWEB)

Royer, J C; Nakas, J P [State Univ. of New York, Syracuse, NY (USA). Coll. of Environmental Science and Forestry

1989-07-01

Xylan comprises up to 25% of hardwood biomass and is found in a variety of agricultural residues. It therefore represents a significant renewable resource which should be utilized to improve the economics of bioconversion of plant biomass to useful products. Before fermentation to fuels or solvents, xylan must be hydrolysed to xylose or short-chain oligomers of xylose. The effects of carbon source, substrate concentration, culture pH, and spore inoculum concentration on production of extracellular xylanase and cellulase were examined. Very low enzyme activities were obtained with growth on glucose, xylose, and cellobiose, while significantly higher levels were produced from lactose and arabinose. Higher levels of both enzymes were generated from alpha cellulose, wood pulp, and fibrous paper waste than from purified xylan. (author).

Characterization of a novel xylanase gene from rumen content of Hu sheep.

Science.gov (United States)

Wang, Qian; Luo, Yang; He, Bo; Jiang, Lin-Shu; Liu, Jian-Xin; Wang, Jia-Kun

2015-12-01

A novel xylanase gene, xyn-lxy, was cloned from a metagenomic fosmid library, which was previously constructed from the rumen contents of Hu sheep and was functionally characterized in Escherichia coli. The open reading frame was composed of 1923 bp and encoded for 640 amino acids, including a catalytic domain of glycosyl hydrolase family 10 and carbohydrate-binding module 9. The gene showed 97 % identity with uncultured bacterium Contig1552 but low similarity with xylanases from known cellulolytic-degrading microorganisms in the rumen. The recombinant XYN-LXY showed a specific activity of 664.7 U mg(-1). The optimal temperature and pH of the enzyme were 50 °C and 6.0, respectively. Specifically, XYN-LXY was exclusively activated by Mn(2+) among all of the cations and reducing agents tested in this study. An enzymatic hydrolysis assay revealed that XYN-LXY degraded birchwood xylan into xylooligosaccharide with a low degree of polymerization. After incubation for 4 h, the concentration of the dominant product, xylobiose, was 2.297 ± 0.175 mg ml(-1) (74.07 % of total product) followed by xylose with a concentration of 0.656 ± 0.010 mg ml(-1) (21.14 % of total product). The XYN-LXY exhibited deep degradation effects on the xylan substrate, which were rarely observed with endo-xylanase, making it a promising candidate for industrial application, especially in biofuel production.

Optimization of Cellulase and Xylanase Production by Micrococcus Species under Submerged Fermentation

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Ziyanda Mmango-Kaseke

2016-11-01

Full Text Available This paper reports on the optimization of culture conditions for cellulase and xylanase production by bacterial isolate from lignocellulosic biomass. The bacterial isolate was screened for cellulase and xylanase production on carboxyl methyl cellulose (CMC and birch wood xylan as substrates, respectively. One bacterial isolate showing the highest halo zone diameter (isolate PLY1 was selected for detailed studies. The analysis of the 16S ribosomal ribonucleic acid (rRNA gene nucleotide sequence of PLY1 revealed it to have 98% similarity to Micrococcus luteus strain Fse9 and the sequence was deposited in the GenBank as Micrococcus luteus strain SAMRC-UFH3 with accession number KU171371. Cellulase production was achieved in the presence of CMC (1% w/v under an incubation temperature of 25 °C (198 U/mL, pH 5 (173 U/mL, agitation speed 50 rpm (173 U/mL and incubation period of 96 h (102 U/mL. Xylanase was produced maximally when birch wood xylan (1% w/v was used as the substrate at 25 °C (1007 U/mL, pH 10 (2487 U/mL, 200 rpm (1814 U/mL, and under an incubation period of 84 h (1296 U/mL. Our findings showed that Micrococcus sp. SAMRC-UFH3 appears to be a potentially important candidate for lignocellulosic waste degradation and other relevant industrial applications.

CLONING, PURIFICATION AND CHARACTERIZATION OF HALOTOLERANT XYLANASE FROM Geobacillus Thermodenitrificans C5

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Muhammad Irfan

2016-06-01

Full Text Available High levels of extracellular xylanase activity (994.50 IU/ml produced by Geobacillus thermodenitrificans C5 originated gene was detected when it was expressed in E. coli BL21 host. Thermostable xylanase (GthC5Xyl was purified to homogeneity and showed a molecular mass of approximately 44 kDa according to SDS-PAGE. The specific activity of the purified GthC5Xyl was up to 1243.125IU/mg with a 9.89-fold purification. The activity of GthC5Xyl was stimulated by CoCl2, MnSO4, CuSO4, MnCl2 but was inhibited by FeSO4, Hg, CaSO4. GthC5Xyl showed resistant to SDS, Tween 20, Triton X-100, β- Mercaptoethanol, PMSF, DTT, NEM and DEPC, SDS, and EDTA. A greater affinity for oat spelt xylan was exhibited by GthC5Xyl with maximum enzymatic activity at 60°C and 6.0 pH. The activity portrayed by GthC5Xyl was found to be acellulytic with stability at high temperature (70°C-80°C and low pH (4.0 to 8.0. Xylobiose and xylopentose were the end products of proficient oat spelt xylanase hydrolysis by GthC5Xyl. High SDS resistance and broader stability of GthC5Xyl proves it to be worthy of impending application in numerous industrial processes especially textile, detergents and animal feed industry.

Enhanced sugar production from pretreated barley straw by additive xylanase and surfactants in enzymatic hydrolysis for acetone-butanol-ethanol fermentation.

Science.gov (United States)

Yang, Ming; Zhang, Junhua; Kuittinen, Suvi; Vepsäläinen, Jouko; Soininen, Pasi; Keinänen, Markku; Pappinen, Ari

2015-01-01

This study aims to improve enzymatic sugar production from dilute sulfuric acid-pretreated barley straw for acetone-butanol-ethanol (ABE) fermentation. The effects of additive xylanase and surfactants (polyethylene glycol [PEG] and Tween) in an enzymatic reaction system on straw hydrolysis yields were investigated. By combined application of 2g/100g dry-matter (DM) xylanase and PEG 4000, the glucose yield was increased from 53.2% to 86.9% and the xylose yield was increased from 36.2% to 70.2%, which were considerably higher than results obtained with xylanase or surfactant alone. The ABE fermentation of enzymatic hydrolysate produced 10.8 g/L ABE, in which 7.9 g/L was butanol. The enhanced sugar production increased the ABE yield from 93.8 to 135.0 g/kg pretreated straw. The combined application of xylanase and surfactants has a large potential to improve sugar production from barley straw pretreated with a mild acid and that the hydrolysate showed good fermentability in ABE production. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preservation of Bacillus pumilus PU4-2 xylanases by immobilization technique into pollard and cation addition

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T Haryati

2010-03-01

Full Text Available Utilization of by-product from agriculture as alternative source of feedstuff has been widely practiced. However their usage is limited due to high fiber content and low nutrient digestibility. The use of specific hydrolizing enzymes, xylanases are gaining importance because of their wide application in various industrial sectors especially in bioconversion of hemicellulosic material. This experiment was done to evaluate the effect of cation addition and immobilization of enzyme into pollard on stability of B. pumilus xylanase. The enzyme extract was purified by precipitation with 75% ammonium sulphate. Four kinds of cation (Ca2+, Fe3+, Mg2+, Zn2+ were added to the purified enzyme, at concentration of 1m M and stored at 4 and 27˚C. For immobilization process, the optimum enzyme concentration that will be added to pollard has been evaluated by analysis of xylanase activity and their recovery. The specific activity of enzyme after precipitation increased 1.8 times, from 420.3 to 765.2 U/mg protein. All cations act as activator which relative activity become 130.6; 139.0; 103.8 and 163.5% respectively. Concentration of 0.5mM Ca2+ and Fe3+ were most able to keep xylanases activity stable at 4˚C. The optimum composition of enzymes and pollard was 1.5 ml for 5 gram of pollard with recovery of xylanases activity of 82.2%. In immobilized enzyme, the activity of enzyme without cation addition is higher than that with addition of Ca2+ and Fe3+. Activity of enzyme stored at 4˚C is more stable than that at 27˚C. Immobilized enzyme is more stable for storage, which lasted for 7 weeks at 27˚C and 12 weeks at 4˚C compared to liquid enzyme which lasted for only 7 days at 27˚C and 13 days at 4˚C.

The Botrytis cinerea xylanase Xyn11A contributes to virulence with its necrotizing activity, not with its catalytic activity

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González Celedonio

2010-02-01

Full Text Available Abstract Background The Botrytis cinerea xylanase Xyn11A has been previously shown to be required for full virulence of this organism despite its poor contribution to the secreted xylanase activity and the low xylan content of B. cinerea hosts. Intriguingly, xylanases from other fungi have been shown to have the property, independent of the xylan degrading activity, to induce necrosis when applied to plant tissues, so we decided to test the hypothesis that secreted Xyn11A contributes to virulence by promoting the necrosis of the plant tissue surrounding the infection, therefore facilitating the growth of this necrotroph. Results We show here that Xyn11A has necrotizing activity on plants and that this capacity is conserved in site-directed mutants of the protein lacking the catalytic activity. Besides, Xyn11A contributes to the infection process with the necrotizing and not with the xylan hydrolyzing activity, as the catalytically-impaired Xyn11A variants were able to complement the lower virulence of the xyn11A mutant. The necrotizing activity was mapped to a 30-amino acids peptide in the protein surface, and this region was also shown to mediate binding to tobacco spheroplasts by itself. Conclusions The main contribution of the xylanase Xyn11A to the infection process of B. cinerea is to induce necrosis of the infected plant tissue. A conserved 30-amino acids region on the enzyme surface, away from the xylanase active site, is responsible for this effect and mediates binding to plant cells.

Xylanase production from Thermomyces lanuginosus VAPS-24 using low cost agro-industrial residues via hybrid optimization tools and its potential use for saccharification.

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Kumar, Vishal; Chhabra, Deepak; Shukla, Pratyoosh

2017-11-01

The xylanase production from Thermomyces lanuginosus VAPS-24 has been optimized using OFAT (One factor at a time) approach using agro-industrial substrates. Further, central composite design (CCD) has been employed to optimize various process parameters such as temperature (45-55°C), carbon source concentration (1.5-2.5%), fermentation time (72-120h) and production medium pH (6-8). Maximum xylanase yield after RSM optimization was approximately double (119.91±2.53UmL -1 ) than un-optimized conditions (61.09±0.91UmL -1 ). Several hybrid statistical tools such as Genetic Algorithm-Response Surface Methodology (GA-RSM), Artificial Neural Network (ANN), Genetic Algorithm-Artificial Neural Network (GA-ANN) were employed to obtain more optimized process parameters to maximize the xylanase production and observed an increase of 10.50% xylanase production (132.51±3.27UmL -1 ) as compared to RSM response (119.91±2.53UmL -1 ). The various pretreated and untreated agricultural residues were subjected to saccharification by using crude xylanase in which the pretreated rice straw yielded maximum fermentable sugars 126.89mgg -1 . Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of high level of cellulase-free xylanase by the thermophilic fungus Thermomyces lanuginosus in laboratory and pilot scales using lignocellulosic materials

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Gomes, J [Institute of Biotechnology, Technical Univ. of Graz (Austria); Purkarthofer, H [Institute of Biotechnology, Technical Univ. of Graz (Austria); Hayn, M [Institute of Biochemistry, Univ. of Graz (Austria); Kapplmueller, J [Voest-Alpine Industrieanlagen GmbH, Zellstofftechnik und Biomasseverwertung, Linz (Austria); Sinner, M [Voest-Alpine Industrieanlagen GmbH, Zellstofftechnik und Biomasseverwertung, Linz (Austria); Steiner, W [Institute of Biotechnology, Technical Univ. of Graz (Austria)

1993-08-01

Thermomyces lanuginosus, isolated from self-heated jute stacks in Bangladesh, was able to produce a very high level of cellulase-free xylanase in shake cultures using inexpensive lignocellulosic biomass. Of the nine lignocellulosic substrates tested, corn cobs were found to be the best inducer of xylanase activity. The laboratory results of xylanase production have been successfully scaled up to VABIO (Voest-Alpine Biomass Technology Center) scale using a 15-m[sup 3] fermentor for industrial production and application of xylanase. In addition, some properties of the enzyme in crude culture filtrate produced on corn cobs are presented. The enzyme exhibited very satisfactory storage stability at 4-30 C either as crude culture filtrate or as spray- or freeze-dried powder. The crude enzyme was active over a broad range of pH and had activity optima at pH 6.5 and 70-75 C. The enzyme was almost thermostable (91-92%) at pH 6.5 and 9.0 after 41 h preincubation at 55 C and lost only 20-33% activity after 188 h. In contrast, it was much less thermostable at pH 5.0 and 11.0 Xylanases produced on different lignocellulosic substrates exhibited differences in thermostability at 55 C and pH 6.5. (orig.)

Structural Insights into the Thermophilic Adaption Mechanism of Endo-1,4-β-Xylanase from Caldicellulosiruptor owensensis.

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Liu, Xin; Liu, Tengfei; Zhang, Yuebin; Xin, Fengjiao; Mi, Shuofu; Wen, Boting; Gu, Tianyi; Shi, Xinyuan; Wang, Fengzhong; Sun, Lichao

2018-01-10

Xylanases (EC 3.2.1.8) are a kind of enzymes degrading xylan to xylooligosaccharides (XOS) and have been widely used in a variety of industrial applications. Among them, xylanases from thermophilic microorganisms have distinct advantages in industries that require high temperature conditions. The CoXynA gene, encoding a glycoside hydrolase (GH) family 10 xylanase, was identified from thermophilic Caldicellulosiruptor owensensis and was overexpressed in Escherichia coli. Recombinant CoXynA showed optimal activity at 90 °C with a half-life of about 1 h at 80 °C and exhibited highest activity at pH 7.0. The activity of CoXynA activity was affected by a variety of cations. CoXynA showed distinct substrate specificities for beechwood xylan and birchwood xylan. The crystal structure of CoXynA was solved and a molecular dynamics simulation of CoXynA was performed. The relatively high thermostability of CoXynA was proposed to be due to the increased overall protein rigidity resulting from the reduced length and fluctuation of Loop 7.

Aspects microbiologiques de la production par fermentation solide des endo-beta-1,4-xylanases de moisissures : le cas de Penicillium canescens

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Assamoi AA.

2009-01-01

Full Text Available Microbial aspects of endo-β-1,4-xylanase production in solid-state fermentation by Penicillia: the case of Penicillium canescens. Production of xylanases by Penicillium canescens 10-10c is the research object in Walloon Center of Industrial Biology. Previous works used submerged or liquid fermentation. The actual works are oriented more and more towards solid fermentation from agricultural or agro-alimentary residues. In addition to the valorization of these residues, solid-state fermentation reaches an increasingly significant interest in various other fields like the biological breakdown of the solid residues, the bioremediation of the organic pollutants in the grounds and the reduction of the air pollution by the biofiltration. Xylanase is an industrial enzyme used in general in extraction and clarification processes. P. canescens can produce an activity of it, particularly in its balanced forms of xylanases, beta-xylosidase and arabinosidase, and not contaminated by cellulolytic and amylolytic activities. It is a hyper producing strain of xylanase. The production rate is one of the highest in literature (535 U.ml-1 and 9,632 U.g-1 in Erlenmeyer flasks, in submerged and solid state fermentation, respectively. The biobleaching activity of the cellulose pulp by the purified enzyme is higher than a commercial preparation of xylanases from Trichoderma longibrachiatum used industrially. It has a complete hydrolysis degree of 40% (on glucuronoxylan and 35% (on arabinoxylan at 55°C and at pH of 5.9. These characteristics lead to many industrial applications of this enzyme. That is why the optimization of its production by the solid-state fermentation at the laboratory scale in order to define a policy for the industrial transposition later is carried out. This article presents a summary of the scientific literature on this subject.

Cloning of a novel xylanase gene from a newly isolated Fusarium sp. Q7-31 and its expression in Escherichia coli

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Zhan-Ling Xie

2012-03-01

Full Text Available A strain of Q7-31 was isolated from Qinghai-Tibet Plateau and was identified as Fusarium sp. based on its morphological characteristics and ITS rDNA gene sequence analysis. It has the highest capacity of degrading cell wall activity compared with other 11 strains. To do research on its xylanase activity of Fusarium sp. Q7-31 while the degrading the rice cell walls, the complete gene xyn8 that encodes endo-1, 4-β-xylanase secreted by Fusarium sp. Q7-31 was cloned and sequenced. The coding region of the gene is separated by two introns of 56bp and 55bp. It encodes 230 amino acid residues of a protein with a calculated molecular weight of 25.7 kDa. The animo acids sequence of xyn8 gene has higher similarity with those of family 11 of glycosyl hydrolases reported from other microorganisms. The nature peptide encodeing cDNA was subcloned into pGEX5x-1 expression vector. The recombinant plasmid was expressed in Escherichia coli BL21-CodonPlus (DE3-RIL, and xylanase activity was measured. The expression fusion protein was identified by SDS-PAGE and Western blotting, a new specific band of about 52kDa was identified when induced by IPTG. Enzyme activity assay verified the recombinants proteins as a xylanase. A maxium activity of 2.34U/ mg, the xylanase had optimal activity at pH 6.0 and temperature 40ºC .

A highly thermostable alkaline cellulase-free xylanase from thermoalkalophilic Bacillus sp. JB 99 suitable for paper and pulp industry: purification and characterization.

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Shrinivas, Dengeti; Savitha, Gunashekaran; Raviranjan, Kumar; Naik, Gajanan Ramchandra

2010-11-01

A highly thermostable alkaline xylanase was purified to homogeneity from culture supernatant of Bacillus sp. JB 99 using DEAE-Sepharose and Sephadex G-100 gel filtration with 25.7-fold increase in activity and 43.5% recovery. The molecular weight of the purified xylanase was found to be 20 kDA by SDS-PAGE and zymogram analysis. The enzyme was optimally active at 70 °C, pH 8.0 and stable over pH range of 6.0-10.0.The relative activity at 9.0 and 10.0 were 90% and 85% of that of pH 8.0, respectively. The enzyme showed high thermal stability at 60 °C with 95% of its activity after 5 h. The K (m) and V (max) of enzyme for oat spelt xylan were 4.8 mg/ml and 218.6 µM min(-1) mg(-1), respectively. Analysis of N-terminal amino acid sequence revealed that the xylanase belongs to glycosyl hydrolase family 11 from thermoalkalophilic Bacillus sp. with basic pI. Substrate specificity showed a high activity on xylan-containing substrate and cellulase-free nature. The hydrolyzed product pattern of oat spelt xylan on thin-layer chromatography suggested xylanase as an endoxylanase. Due to these properties, xylanase from Bacillus sp. JB 99 was found to be highly compatible for paper and pulp industry.

Heterologous expression of xylanase enzymes in lipogenic yeast Yarrowia lipolytica.

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Wei Wang

Full Text Available To develop a direct microbial sugar conversion platform for the production of lipids, drop-in fuels and chemicals from cellulosic biomass substrate, we chose Yarrowia lipolytica as a viable demonstration strain. Y. lipolytica is known to accumulate lipids intracellularly and is capable of metabolizing sugars to produce lipids; however, it lacks the lignocellulose-degrading enzymes needed to break down biomass directly. While research is continuing on the development of a Y. lipolytica strain able to degrade cellulose, in this study, we present successful expression of several xylanases in Y. lipolytica. The XynII and XlnD expressing Yarrowia strains exhibited an ability to grow on xylan mineral plates. This was shown by Congo Red staining of halo zones on xylan mineral plates. Enzymatic activity tests further demonstrated active expression of XynII and XlnD in Y. lipolytica. Furthermore, synergistic action in converting xylan to xylose was observed when XlnD acted in concert with XynII. The successful expression of these xylanases in Yarrowia further advances us toward our goal to develop a direct microbial conversion process using this organism.

Influence of a direct-fed microbial and xylanase enzyme on the dietary energy uptake efficiency and performance of broiler chickens.

Science.gov (United States)

Murugesan, Ganapathi Raj; Persia, Michael E

2015-09-01

Efficacy of a multi-strain direct-fed microbial product (PoultryStar(®) ME; PS) and a xylanase enzyme product on the dietary energy utilization efficiency and resulting performance in broiler chickens was evaluated. Apart from performance parameters, cecal and serum metabolites and activities of hepatic enzymes involved in energy metabolism were also determined. Ross 308 chicks were fed one of four experimental diets [control (CON), CON + PS, CON + xylanase and CON + PS + xylanase] using a 2 × 2 factorial arrangement from 1-21 days of age. Cecal proportions of propionate and butyrate, as well as total short-chain fatty acid concentration were increased (P energy uptake and hepatic energy retention. The combination additively increased the FCR, suggesting involvement of synergistic modes of actions. © 2014 Society of Chemical Industry.

A thermostable Gloeophyllum trabeum xylanase with potential for the brewing industry.

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Wang, Xiaoyu; Luo, Huiying; Yu, Wangning; Ma, Rui; You, Shuai; Liu, Weina; Hou, Lingyu; Zheng, Fei; Xie, Xiangming; Yao, Bin

2016-05-15

A xylanase gene of glycoside hydrolase family 10, GtXyn10, was cloned from Gloeophyllum trabeum CBS 900.73 and expressed in Pichia pastoris GS115. Purified recombinant GtXyn10 exhibited significant activities to xylan (100.0%), lichenan (11.2%), glucan (15.2%) and p-nitrophenol-β-cellobiose (18.6%), demonstrated the maximum xylanase and glucanase activities at pH 4.5-5.0 and 75°C, retained stability over the pH range of 2.0-7.5 and at 70°C, and was resistant to pepsin and trypsin, most metal ions and SDS. Multiple sequence alignment and modeled-structure analysis identified a unique Gly48 in GtXyn10, and site-directed mutagenesis of Gly48 to Lys improved the temperature optimum up to 80°C. Under simulated mashing conditions, GtXyn10 (80U) reduced the mash viscosity by 12.8% and improved the filtration rate by 31.3%. All these properties above make GtXyn10 attractive for potential applications in the feed and brewing industries. Copyright © 2015 Elsevier Ltd. All rights reserved.

The enhancement of enzymatic hydrolysis of lignocellulosic substrates by the addition of accessory enzymes such as xylanase: is it an additive or synergistic effect?

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Saddler Jack N

2011-10-01

Full Text Available Abstract Background We and other workers have shown that accessory enzymes, such as β-glucosidase, xylanase, and cellulase cofactors, such as GH61, can considerably enhance the hydrolysis effectiveness of cellulase cocktails when added to pretreated lignocellulosic substrates. It is generally acknowledged that, among the several factors that hamper our current ability to attain efficient lignocellulosic biomass conversion yields at low enzyme loadings, a major problem lies in our incomplete understanding of the cooperative action of the different enzymes acting on pretreated lignocellulosic substrates. Results The reported work assessed the interaction between cellulase and xylanase enzymes and their potential to improve the hydrolysis efficiency of various pretreated lignocellulosic substrates when added at low protein loadings. When xylanases were added to the minimum amount of cellulase enzymes required to achieve 70% cellulose hydrolysis of steam pretreated corn stover (SPCS, or used to partially replace the equivalent cellulase dose, both approaches resulted in enhanced enzymatic hydrolysis. However, the xylanase supplementation approach increased the total protein loading required to achieve significant improvements in hydrolysis (an additive effect, whereas the partial replacement of cellulases with xylanase resulted in similar improvements in hydrolysis without increasing enzyme loading (a synergistic effect. The enhancement resulting from xylanase-aided synergism was higher when enzymes were added simultaneously at the beginning of hydrolysis. This co-hydrolysis of the xylan also influenced the gross fiber characteristics (for example, fiber swelling resulting in increased accessibility of the cellulose to the cellulase enzymes. These apparent increases in accessibility enhanced the steam pretreated corn stover digestibility, resulting in three times faster cellulose and xylan hydrolysis, a seven-fold decrease in cellulase loading and

The crystal structures of the tri-functional Chloroflexus aurantiacus and bi-functional Rhodobacter sphaeroides malyl-CoA lyases and comparison with CitE-like superfamily enzymes and malate synthases.

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Zarzycki, Jan; Kerfeld, Cheryl A

2013-11-09

Malyl-CoA lyase (MCL) is a promiscuous carbon-carbon bond lyase that catalyzes the reversible cleavage of structurally related Coenzyme A (CoA) thioesters. This enzyme plays a crucial, multifunctional role in the 3-hydroxypropionate bi-cycle for autotrophic CO2 fixation in Chloroflexus aurantiacus. A second, phylogenetically distinct MCL from Rhodobacter sphaeroides is involved in the ethylmalonyl-CoA pathway for acetate assimilation. Both MCLs belong to the large superfamily of CitE-like enzymes, which includes the name-giving β-subunit of citrate lyase (CitE), malyl-CoA thioesterases and other enzymes of unknown physiological function. The CitE-like enzyme superfamily also bears sequence and structural resemblance to the malate synthases. All of these different enzymes share highly conserved catalytic residues, although they catalyze distinctly different reactions: C-C bond formation and cleavage, thioester hydrolysis, or both (the malate synthases). Here we report the first crystal structures of MCLs from two different phylogenetic subgroups in apo- and substrate-bound forms. Both the C. aurantiacus and the R. sphaeroides MCL contain elaborations on the canonical β8/α8 TIM barrel fold and form hexameric assemblies. Upon ligand binding, changes in the C-terminal domains of the MCLs result in closing of the active site, with the C-terminal domain of one monomer forming a lid over and contributing side chains to the active site of the adjacent monomer. The distinctive features of the two MCL subgroups were compared to known structures of other CitE-like superfamily enzymes and to malate synthases, providing insight into the structural subtleties that underlie the functional versatility of these enzymes. Although the C. aurantiacus and the R. sphaeroides MCLs have divergent primary structures (~37% identical), their tertiary and quaternary structures are very similar. It can be assumed that the C-C bond formation catalyzed by the MCLs occurs as proposed for

Wheat dough rheology at low water contents and the influence of xylanases

NARCIS (Netherlands)

Hardt, N.A.; Boom, R.M.; Goot, van der A.J.

2014-01-01

The effect of low water contents and xylanases on wheat dough rheology is reported. Farinograph, dynamic oscillation, and creep-recovery measurements were performed using water concentrations from 34 to 44.8% (total basis). A water reduction from 43.5–44.8% to 34% increased resistance upon mixing as

Novel structural features of xylanase A1 from Paenibacillus sp. JDR-2

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Franz J. St John; James F. Preston; Edwin Pozharski

2012-01-01

The Gram-positive bacterium Paenibacillus sp. JDR-2 (PbJDR2) has been shown to have novel properties in the utilization of the abundant but chemically complex hemicellulosic sugar glucuronoxylan. Xylanase A1 of PbJDR2 (PbXynA1) has been implicated in an efficient process in which extracellular...

Characterization and mode of action of xylanases ␁and some accessory enzymes

NARCIS (Netherlands)

Kormelink, F.J.M.

1992-01-01

Three endo-(l,4)-β-D-xylanases; (Endo I, Endo II, and Endo III), a (1,4)-β-xylosidase and an (1,4)-β-D-arabinoxylan arabinofuranohydrolase (AXH) were purified from a culture filtrate produced by Aspergillus awamori CMI 142717. In addition to these enzymes, an acetyl

Co-cultivation of mutant Penicillium oxalicum SAU(E)-3.510 and Pleurotus ostreatus for simultaneous biosynthesis of xylanase and laccase under solid-state fermentation.

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Dwivedi, Pallavi; Vivekanand, V; Pareek, Nidhi; Sharma, Amit; Singh, Rajesh P

2011-10-01

Co-cultivation of mutant Penicillium oxalicum SAU(E)-3.510 and Pleurotus ostreatus MTCC 1804 was evaluated for the production of xylanase-laccase mixture under solid-state fermentation (SSF) condition. Growth compatibility between mutant P. oxalicum SAU(E)-3.510 and white rot fungi (P. ostreatus MTCC 1804, Trametes hirsuta MTCC 136 and Pycnoporus sp. MTCC 137) was analyzed by growing them on potato dextrose agar plate. Extracellular enzyme activities were determined spectrophotometrically. Under derived conditions, paired culturing of mutant P. oxalicum SAU(E)-3.510 and P. ostreatus MTCC 1804 resulted in 58% and 33% higher levels of xylanase and laccase production, respectively. A combination of sugarcane bagasse and black gram husk in a ratio of 3:1 was found to be the most ideal solid substrate and support for fungal colonization and enzyme production during co-cultivation. Maximum levels of xylanase (8205.31 ± 168.31 IU g(-1)) and laccase (375.53 ± 34.17 IU g(-1)) during SSF were obtained by using 4 g of solid support with 80% of moisture content. Furthermore, expressions of both xylanase and laccase were characterized during mixed culture by zymogram analysis. Improved levels of xylanase and laccase biosynthesis were achieved by co-culturing the mutant P. oxalicum SAU(E)-3.510 and P. ostreatus MTCC 1804. This may be because of efficient substrate utilization as compared to their respective monocultures in the presence of lignin degradation compounds because of synergistic action of xylanase and laccase. Understanding and developing the process of co-cultivation appears productive for the development of mixed enzyme preparation with tremendous potential for biobleaching. Copyright © 2011 Elsevier B.V. All rights reserved.

Purification and characterization of five cellulases and one xylanase from Penicillium brasilianum IBT 20888

DEFF Research Database (Denmark)

Jørgensen, Henning; Eriksson, T.; Borjesson, J.

2003-01-01

The filamentous fungus Penicillium brasilianum IBT 20888 was cultivated on a mixture of 30 g l(-1) cellulose and 10 g l(-1) xylan for 111 h and the resulting culture filtrate was used for protein purification. From the cultivation broth, five cellulases and one xylanase were purified. Hydrolysis...... studies revealed that two of the cellulases were acting as cellobiohydrolases by being active on only microcrystalline cellulose (Avicel). Three of the cellulases were active on both Avicel and carboxymethyl cellulose indicating endoglucanase activity. Two of these showed furthermore mannanase activity...... the cellulose-binding domain or an essential part of it. The basic xylanase (pI > 9) was only active towards xylan. Two of the purified cellulases with endoglucanase activity were partly sequenced and based on sequence homology with known enzymes they were classified as belonging to families 5 and 12...

Cellulase and xylanase productions by isolated Amazon Bacillus strains using soybean industrial residue based solid-state cultivation

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Heck Júlio X.

2002-01-01

Full Text Available In Brazil, a large amount of a fibrous residue is generated as result of soybean (Glycine max protein production. This material, which is rich in hemicellulose and cellulose, can be used in solid state cultivations for the production of valuable metabolites and enzymes. In this work, we studied the bioconversion of this residue by bacteria strains isolated from water and soil collected in the Amazon region. Five strains among 87 isolated bacteria selected for their ability to produce either celullases or xylanases were cultivated on the aforementioned residue. From strain BL62, identified as Bacillus subtilis, it was obtained a preparation showing the highest specific cellulase activity, 1.08 UI/mg protein within 24 hours of growth. Concerning xylanase, the isolate BL53, also identified as Bacillus subtilis, showed the highest specific activity for this enzyme, 5.19 UI/mg protein within 72 hours of cultivation. It has also been observed the production of proteases that were associated with the loss of cellulase and xylanase activities. These results indicated that the selected microorganisms, and the cultivation process, have great biotechnological potential.

Xylanase and cellulase activities during anaerobic decomposition of three aquatic macrophytes.

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Nunes, Maíra F; da Cunha-Santino, Marcela B; Bianchini, Irineu

2011-01-01

Enzymatic activity during decomposition is extremely important to hydrolyze molecules that are assimilated by microorganisms. During aquatic macrophytes decomposition, enzymes act mainly in the breakdown of lignocellulolytic matrix fibers (i.e. cellulose, hemicellulose and lignin) that encompass the refractory fraction from organic matter. Considering the importance of enzymatic activities role in decomposition processes, this study aimed to describe the temporal changes of xylanase and cellulose activities during anaerobic decomposition of Ricciocarpus natans (freely-floating), Oxycaryum cubense (emergent) and Cabomba furcata (submersed). The aquatic macrophytes were collected in Óleo Lagoon, Luiz Antonio, São Paulo, Brazil and bioassays were accomplished.  Decomposition chambers from each species (n = 10) were set up with dried macrophyte fragments and filtered Óleo Lagoon water. The chambers were incubated at 22.5°C, in the dark and under anaerobic conditions. Enzymatic activities and remaining organic matter were measured periodically during 90 days. The temporal variation of enzymes showed that C. furcata presented the highest decay and the highest maximum enzyme production. Xylanase production was higher than cellulase production for the decomposition of the three aquatic macrophytes species.

Alteration of white-rot basidiomycetes cellulase and xylanase activities in the submerged co-cultivation and optimization of enzyme production by Irpex lacteus and Schizophyllum commune.

Science.gov (United States)

Metreveli, Eka; Kachlishvili, Eva; Singer, Steven W; Elisashvili, Vladimir

2017-10-01

Mono and dual cultures of four white-rot basidiomycete species were evaluated for cellulase and xylanase activity under submerged fermentation conditions. Co-cultivation of Pycnoporus coccineus or Trametes hirsuta with Schizophyllum commune displayed antagonistic interactions resulting in the decrease of endoglucanase and total cellulase activities. In contrast, increases in cellulase and xylanase activity were revealed through the compatible interactions of Irpex lacteus with S. commune. Co-cultivation conditions were optimized for maximum enzyme production by I. lacteus and S. commune, the best producers of cellulase/xylanase and β-glucosidase, respectively. An optimized medium for the target enzyme production by the mixed culture was established in a laboratory fermenter yielding 7U/mL total cellulase, 142U/mL endoglucanase, 104U/mL xylanase, and 5.2U/mL β-glucosidase. The dual culture approach resulted in an enzymatic mixture with 11% improved lignocellulose saccharification potential compared to enzymes from a monoculture of I. lacteus. Copyright © 2017 Elsevier Ltd. All rights reserved.

Application of xylanases from Amazon Forest fungal species in bleaching of eucalyptus kraft pulps

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Roseli Garcia Medeiros

2007-03-01

Full Text Available Crude xylanase preparations from Penicillium corylophilum, Aspergillus niger and Trichoderma longibrachiatum were used to treat Eucalyptus kraft pulp, prior to chlorine dioxide and alkaline bleaching sequences. The enzyme pretreatment improved brightness and delignification of non-delignified and oxygen-bleached samples of eucalyptus kraft pulp. Xylanase preparations from T. longibrachiatum and P. corylophilum were more effective to reduce pulp kappa number. A small reduction in viscosity was obtained when the oxygen-bleached pulp was treated with xylanase preparation from A. niger. For all enzyme samples, the best release of chromophoric material from the pulp was at 237 nm. The enzyme preparation from P. corylophilum was responsible for the highest release of reducing sugar at a dosage interval of 10-20 IU/g dry weight pulp. Scanning electron microscopy studies of oxygen-bleached pulp after xylanase treatment revealed morphological changes, including holes, cracks, filament forming and peeling.Amostras de xilanases de extratos brutos de Penicillium corylophilum, Aspergillus niger e Trichoderma longibrachiatum foram utilizadas no branqueamento de polpa kraft de eucalipto antes das seqüências alcalina e dióxido de cloro. O pré-tratamento enzimático melhorou a alvura e o processo de deslignificação de amostras de polpa kraft de eucalipto não-tratada e tratada com oxigênio. Amostras de xilanases de T. longibrachiatum e P. corylophilum foram mais efetivas na redução do número kappa da polpa. A polpa tratada com oxigênio sofreu uma pequena redução na sua viscosidade quando incubada com amostra de xilanase de A. niger. Para todas as amostras de xilanases, a maior liberação de cromóforos da polpa foi a 237 nm. A amostra de xilanase de P. corylophilum liberou maior quantidade de açúcar redutor da polpa, utilizando dosagem de 10-20 UI/g de peso seco da polpa. Estudos de microscopia eletrônica de varredura revelaram várias altera

Xylanase and Protease Increase Solubilization of Non-Starch Polysaccharides and Nutrient Release of Corn- and Wheat Distillers Dried Grains with Solubles

DEFF Research Database (Denmark)

Pedersen, Mads Brøgger; Dalsgaard, Søren; Arent, Susan

2015-01-01

The use of distiller dried grains with solubles (DDGS) as alternative to conventional animal feed for non-ruminants is challenged by the high content of non-starch polysaccharides and varying protein quality. In this study the enzymatic degradation of corn- and wheat DDGS was evaluated, in vitro...... of this xylanase. The current in vitro results indicate a high potential of xylanase in combination with protease to efficiently degrade DDGS and promote nutrient release in diets for non-ruminant animals....

An explanation for the combined effect of xylanase-glucose oxidase in dough systems

NARCIS (Netherlands)

Primo-Martín, C.; Wang, M.; Lichtendonk, W.J.; Plijter, J.J.; Hamer, R.J.

2005-01-01

In the bakery industry, glucose oxidase is usually used in combination with xylanase. Although many theories exist on the mechanism of action of each enzyme, the positive effect of combining the two is as yet unexplained. In this paper we studied a possible basis for this synergy by focusing on the

Cloning, sequencing and expression of a xylanase gene from the maize pathogen Helminthosporium turcicum

DEFF Research Database (Denmark)

Degefu, Y.; Paulin, L.; Lübeck, Peter Stephensen

2001-01-01

A gene encoding an endoxylanase from the phytopathogenic fungus Helminthosporium turcicum Pass. was cloned and sequenced. The entire nucleotide sequence of a 1991 bp genomic fragment containing an endoxylanase gene was determined. The xylanase gene of 795 bp, interrupted by two introns of 52 and ...

Bi-functional fusion enzyme EG-M-Xyn displaying endoglucanase and xylanase activities and its utility in improving lignocellulose degradation.

Science.gov (United States)

Chen, Chin-Chung; Gao, Guo-Jhan; Kao, Ai-Ling; Tsai, Zheng-Chia

2018-05-01

In this study, the gene fusion of endoglucanase (EG, one of cellulases) from Teleogryllus emma and xylanase (Xyn, one of hemicellulases) from Thermomyces lanuginosus was constructed to generate a fusion enzyme (EG-M-Xyn). Through the expression and purification by ultrafiltration and size-exclusion chromatography, the purified EG-M-Xyn had a molecular weight of 75.5 kDa and exhibited the specific activity of CMCase and xylanase as 306.8 U/mg and 1227.3 U/mg, respectively. The K m values (CMC and beechwood xylan) were 6.8 and 60.6 mg mL -1 while catalytic efficiency (k cat /K m ) values of CMCase and xylanase were 3280 and 38,797 min -1  mg -1  mL, respectively. EG-M-Xyn exerted great properties for its great potential in improving the enzymatic hydrolysis of lignocellulosics to produce fermentable sugars. First, EG-M-Xyn showed mild reaction pH and temperature of 5.5 and 50 °C, respectively. Secondly, EG-M-Xyn exhibited great heat tolerance of T 1/2 values of 173 (CMCase) and 693 min (xylanase). Lastly and most importantly, application of EG-M-Xyn in combination with Ctec2 (commercial enzyme) in the saccharification led to a 10-20% net increase in fermentable sugars liberated from pretreated rice straw in comparison to the Ctec2 alone group. In conclusion, EG-M-Xyn had great potential in generating fermentable sugars from renewable agro-residues for biofuel and fine chemical industry. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid 2,2'-bicinchoninic-based xylanase assay compatible with high throughput screening

Science.gov (United States)

William R. Kenealy; Thomas W. Jeffries

2003-01-01

High-throughput screening requires simple assays that give reliable quantitative results. A microplate assay was developed for reducing sugar analysis that uses a 2,2'-bicinchoninic-based protein reagent. Endo-1,4-â-D-xylanase activity against oat spelt xylan was detected at activities of 0.002 to 0.011 IU ml−1. The assay is linear for sugar...

An approach to industrial application: influence of black liquor and pH on xylanase efficiency in bleaching of eucalyptus kraft pulp

OpenAIRE

Fillat Latorre, Úrsula; Roncero Vivero, María Blanca; Bassa, Alexandre; Sacón, Vera Maria

2010-01-01

To obtain a more realistic appraisal of the potential efficiency of xylanases in the industrial bleaching, the influence of pH and the presence of black liquor (measured as COD) on the bleaching efficiency of two commercial xylanases was studied at high temperature. These pH’s, CODs, and temperatures are close to those used in the storage tower of the B fiber line in Jacareı´ unit of Fibria (Brazil). The pulp samples obtained after each bleaching stage were analyzed for kappa number, brigh...

GH10 xylanase D from Penicillium funiculosum: biochemical studies and xylooligosaccharide production

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Giardina Thierry

2011-04-01

Full Text Available Abstract Background The filamentous fungus Penicillium funiculosum produces a range of glycoside hydrolases (GH. The XynD gene, encoding the sole P. funiculosum GH10 xylanase described so far, was cloned into the pPICZαA vector and expressed in methylotrophe yeast Pichia pastoris, in order to compare the results obtained with the P. funiculosum GH11 xylanases data. Results High level expression of recombinant XynD was obtained with a secretion of around 60 mg.L-1. The protein was purified to homogeneity using one purification step. The apparent size on SDS-PAGE was around 64 kDa and was 46 kDa by mass spectrometry thus higher than the expected molecular mass of 41 kDa. The recombinant protein was N- and O-glycosylated, as demonstrated using glycoprotein staining and deglycosylation reactions, which explained the discrepancy in molecular mass. Enzyme-catalysed hydrolysis of low viscosity arabinoxylan (LVAX was maximal at pH 5.0 with Km(app and kcat/Km(app of 3.7 ± 0.2 (mg.mL-1 and 132 (s-1mg-1.mL, respectively. The activity of XynD was optimal at 80°C and the recombinant enzyme has shown an interesting high thermal stability at 70°C for at least 180 min without loss of activity. The enzyme had an endo-mode of action on xylan forming mainly xylobiose and short-chain xylooligosaccharides (XOS. The initial rate data from the hydrolysis of short XOS indicated that the catalytic efficiency increased slightly with increasing their chain length with a small difference of the XynD catalytic efficiency against the different XOS. Conclusion Because of its attractive properties XynD might be considered for biotechnological applications. Moreover, XOS hydrolysis suggested that XynD possess four catalytic subsites with a high energy of interaction with the substrate and a fifth subsite with a small energy of interaction, according to the GH10 xylanase literature data.

Amenability of Acacia and Eucalyptus Hardwood Pulps to Elemental Chlorine-Free Bleaching: Application and Efficacy of Microbial Xylanase

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Avdhesh Kumar Gangwar

2015-10-01

Full Text Available This study outlines the results of a biobleaching study of acacia (A. mangium and eucalyptus (E. globulus hardwood kraft pulps with commercial xylanase (Optimase CX 72 L. The comparative study was carried out using an elemental chlorine-free (ECF bleaching sequence (D0EPD1D2 after the enzyme (X stage. The enzyme treatment resulted in improved optical properties with a reduction in bleach chemical consumption. At an equivalent bleach chemical consumption, a brightness gain of 2.1 and 1.7 units and a whiteness gain of 2.7 and 2.3 units were observed with xylanase treatment in acacia and eucalyptus pulps, respectively. In ECF bleaching using the D0EPD1D2 sequence, a final brightness was achieved to the extent of 90% ISO and 89% ISO for acacia and eucalyptus, respectively, at an equivalent charge of bleach chemicals. The post-color (PC number was also reduced by up to 45% for both hardwood pulps compared with the control. The bleachability of acacia was observed to be significantly higher than that of eucalyptus. In addition, a 17.0% and 23.0% reduction in chlorine dioxide and sodium hydroxide, respectively, were obtained for both hardwood pulps after xylanase pre-bleaching, thus indicating an environmentally friendly approach to the process.

Effects of Xylanase Supplementation on Growth Performance, Nutrient Digestibility and Non-starch Polysaccharide Degradation in Different Sections of the Gastrointestinal Tract of Broilers Fed Wheat-based Diets

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L. Zhang

2014-06-01

Full Text Available This experiment was performed to investigate the effects of exogenous xylanase supplementation on performance, nutrient digestibility and the degradation of non-starch polysaccharides (NSP in different sections of the gastrointestinal tract (GIT of broilers fed wheat-based diets. A total of 120 7-day-old Arbor Acres broiler chicks were randomly allotted to two wheat-based experimental diets supplemented with 0 or 1.0 g/kg xylanase. Each treatment was composed of 6 replicates with 10 birds each. Diets were given to the birds from 7 to 21 days of age. The results showed that xylanase supplementation did not affect feed intake, but increased body weight gain of broiler at 21 day of age by 5.8% (pjejunum>duodenum>>gizzard> caecum. The supplementation of xylanse increased ileal isomaltriose concentration (p<0.05, but did not affect the concentrations of isomaltose, panose and 1-kestose in the digesta of all GIT sections. These results suggest that supplementation of xylanase to wheat-based diets cuts the arabinoxylan backbone into small fragments (mainly arabinose and xylose in the ileum, jejunum and duodenum, and enhances digestibilites of nutrients by decreasing digesta viscosity. The release of arabinose and xylose in the small intestine may also be the important contributors to the growth-promoting effect of xylanase in broilers fed wheat-based diets.

Two new xylanases with different substrate specificities from the human gut bacterium Bacteroides intestinalis DSM 17393.

Science.gov (United States)

Hong, Pei-Ying; Iakiviak, Michael; Dodd, Dylan; Zhang, Meiling; Mackie, Roderick I; Cann, Isaac

2014-04-01

Xylan is an abundant plant cell wall polysaccharide and is a dominant component of dietary fiber. Bacteria in the distal human gastrointestinal tract produce xylanase enzymes to initiate the degradation of this complex heteropolymer. These xylanases typically derive from glycoside hydrolase (GH) families 10 and 11; however, analysis of the genome sequence of the xylan-degrading human gut bacterium Bacteroides intestinalis DSM 17393 revealed the presence of two putative GH8 xylanases. In the current study, we demonstrate that the two genes encode enzymes that differ in activity. The xyn8A gene encodes an endoxylanase (Xyn8A), and rex8A encodes a reducing-end xylose-releasing exo-oligoxylanase (Rex8A). Xyn8A hydrolyzed both xylopentaose (X5) and xylohexaose (X6) to a mixture of xylobiose (X2) and xylotriose (X3), while Rex8A hydrolyzed X3 through X6 to a mixture of xylose (X1) and X2. Moreover, rex8A is located downstream of a GH3 gene (xyl3A) that was demonstrated to exhibit β-xylosidase activity and would be able to further hydrolyze X2 to X1. Mutational analyses of putative active site residues of both Xyn8A and Rex8A confirm their importance in catalysis by these enzymes. Recent genome sequences of gut bacteria reveal an increase in GH8 Rex enzymes, especially among the Bacteroidetes, indicating that these genes contribute to xylan utilization in the human gut.

Two New Xylanases with Different Substrate Specificities from the Human Gut Bacterium Bacteroides intestinalis DSM 17393

KAUST Repository

Hong, Pei-Ying

2014-01-24

Xylan is an abundant plant cell wall polysaccharide and is a dominant component of dietary fiber. Bacteria in the distal human gastrointestinal tract produce xylanase enzymes to initiate the degradation of this complex heteropolymer. These xylanases typically derive from glycoside hydrolase (GH) families 10 and 11; however, analysis of the genome sequence of the xylan-degrading human gut bacterium Bacteroides intestinalis DSM 17393 revealed the presence of two putative GH8 xylanases. In the current study, we demonstrate that the two genes encode enzymes that differ in activity. The xyn8A gene encodes an endoxylanase (Xyn8A), and rex8A encodes a reducing-end xylose-releasing exo-oligoxylanase (Rex8A). Xyn8A hydrolyzed both xylopentaose (X5) and xylohexaose (X6) to a mixture of xylobiose (X2) and xylotriose (X3), while Rex8A hydrolyzed X3 through X6 to a mixture of xylose (X1) and X2. Moreover, rex8A is located downstream of a GH3 gene (xyl3A) that was demonstrated to exhibit β-xylosidase activity and would be able to further hydrolyze X2 to X1. Mutational analyses of putative active site residues of both Xyn8A and Rex8A confirm their importance in catalysis by these enzymes. Recent genome sequences of gut bacteria reveal an increase in GH8 Rex enzymes, especially among the Bacteroidetes, indicating that these genes contribute to xylan utilization in the human gut.

Two New Xylanases with Different Substrate Specificities from the Human Gut Bacterium Bacteroides intestinalis DSM 17393

KAUST Repository

Hong, Pei-Ying; Iakiviak, M.; Dodd, D.; Zhang, M.; Mackie, R. I.; Cann, I.

2014-01-01

Xylan is an abundant plant cell wall polysaccharide and is a dominant component of dietary fiber. Bacteria in the distal human gastrointestinal tract produce xylanase enzymes to initiate the degradation of this complex heteropolymer. These xylanases typically derive from glycoside hydrolase (GH) families 10 and 11; however, analysis of the genome sequence of the xylan-degrading human gut bacterium Bacteroides intestinalis DSM 17393 revealed the presence of two putative GH8 xylanases. In the current study, we demonstrate that the two genes encode enzymes that differ in activity. The xyn8A gene encodes an endoxylanase (Xyn8A), and rex8A encodes a reducing-end xylose-releasing exo-oligoxylanase (Rex8A). Xyn8A hydrolyzed both xylopentaose (X5) and xylohexaose (X6) to a mixture of xylobiose (X2) and xylotriose (X3), while Rex8A hydrolyzed X3 through X6 to a mixture of xylose (X1) and X2. Moreover, rex8A is located downstream of a GH3 gene (xyl3A) that was demonstrated to exhibit β-xylosidase activity and would be able to further hydrolyze X2 to X1. Mutational analyses of putative active site residues of both Xyn8A and Rex8A confirm their importance in catalysis by these enzymes. Recent genome sequences of gut bacteria reveal an increase in GH8 Rex enzymes, especially among the Bacteroidetes, indicating that these genes contribute to xylan utilization in the human gut.

STUDIES ON XYLANASE AND LACCASE ENZYMATIC PREBLEACHING TO REDUCE CHLORINE-BASED CHEMICALS DURING CEH AND ECF BLEACHING

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Vasanta V. Thakur,

2012-02-01

Full Text Available The biobleaching efficiency of xylanase and laccase enzymes was studied on kraft pulps from wood and nonwood based raw materials employed in the Indian paper industry. Treatment of these pulps with xylanase enzyme could result in improved properties, showing 2.0% ISO gain in pulp brightness and/or reducing the demand of chlorine-based bleach chemicals by up to 15% with simultaneous reduction of 20 to 25% in AOX generation in bleach effluents. Further, mill-scale trial results revealed that enzymatic prebleaching can be successfully employed with xylanases to reach the same bleach boosting efficacy. Laccase bleaching was also studied on hardwood pulp at a pH around 8.0, where most of the pulp mills in India are operating, in contrast to earlier studies on laccase enzyme bleaching, which were conducted at acidic pHs, i.e. 4.0 to 5.0. In case of laccase bleaching, interesting results were found wherein a bleach-boosting effect was observed even at pH 8.0. Further studies carried out with HOBT as mediator in comparison to the commonly used and expensive ABTS laccase mediator system (LMS resulted in improvement of the bleaching efficiency with reduction in demand of chlorine dioxide by more than 35%. Potential for further reduction was indicated by the brightness gain, when compared with a control using the DE(pD bleach sequence.

Secretome analysis of the thermophilic xylanase hyper-producer Thermomyces lanuginosus SSBP cultivated on corn cobs.

Science.gov (United States)

Winger, A M; Heazlewood, J L; Chan, L J G; Petzold, C J; Permaul, K; Singh, S

2014-11-01

Thermomyces lanuginosus is a thermophilic fungus known for its ability to produce industrially important enzymes including large amounts of xylanase, the key enzyme in hemicellulose hydrolysis. The secretome of T. lanuginosus SSBP was profiled by shotgun proteomics to elucidate important enzymes involved in hemicellulose saccharification and to characterise the presence of other industrially interesting enzymes. This study reproducibly identified a total of 74 proteins in the supernatant following growth on corn cobs. An analysis of proteins revealed nine glycoside hydrolase (GH) enzymes including xylanase GH11, β-xylosidase GH43, β-glucosidase GH3, α-galactosidase GH36 and trehalose hydrolase GH65. Two commercially produced Thermomyces enzymes, lipase and amylase, were also identified. In addition, other industrially relevant enzymes not currently explored in Thermomyces were identified including glutaminase, fructose-bisphosphate aldolase and cyanate hydratase. Overall, these data provide insight into the novel ability of a cellulase-free fungus to utilise lignocellulosic material, ultimately producing a number of enzymes important to various industrial processes.

Structural Analysis of Xylanase from Marine Thermophilic Geobacillus stearothermophilus in Tanjung Api, Poso, Indonesia

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BUDI SAKSONO

2010-12-01

Full Text Available A xylanase gene, xynA, has been cloned from thermophilic strain Geobacillus stearothermophilus, which was isolated from marine Tanjung Api, Indonesia. The polymerase chain reaction product of 1266 bp of xynA gene consisted of 1221 bp open reading frame and encoded 407 amino acids including 30 residues of signal peptide. The sequence exhibited highest identity of 98.7% in the level of amino acid, with an extracellular endo-1,4-â-xylanase from G stearothermophilus T-6 (E-GSX T-6 of the glycoside hydrolase family 10 (GH10. A comparative study between the local strain G. stearothermophilus (GSX L and E-GSX T-6 on homology of amino acid sequence indicated five differents amino acids in the gene. They were Threonine/Alanine (T/A, Asparagine/Aspartate (N/D, Lysine/Asparagine (K/N, Isoleucine/Methionine (I/M, Serine/Threonine (S/T at the position 220, 227, 228, 233, and 245, respectively. Protein structural analysis of those differences suggested that those amino acids may play role in biochemical properties such as enzyme stability, in particular its thermostability.

Over expression of beta-1, 4-xylanase by auto-induction in E. coli

International Nuclear Information System (INIS)

Khan, M.I.K.; Sajjad, M.; Akhtar, W.

2013-01-01

Catalytic domain of β-1, 4-xylanase gene, (xynZ.CD) of Clostridium thermocellum was cloned in pET28a expression vector and over-expressed in Escherichia colt BL21 CodonPlus (RIL). The production of XynZ.CD in E. colt was optimized using different concentrations of lactose and induction of the enzyme at different stages of growth. The maximum growth of the cells and the enzyme activity were observed when the cells were induced with 10mM lactose after 8 hours of incubation. The enzyme was found to constitute >40% of the total cell proteins in the supernatant of the lysed cells transformed with recombinant pET28a/xynZ.CD. It was purified by heating the cell lysate at 65 degree C for 30 m followed by fractionation through FPLC. Molecular weight of XynZ.CD was found to be approximately 38,524 D by MALDI-TOF analysis. The enzyme variant was quite stable within broad pH range of 5.5 - 8.0 and it retained >85% of xylanase activity after 2 h incubation at 70 degre C. (author)

Gene cloning, overexpression, and characterization of a xylanase from Penicillium sp. CGMCC 1669.

Science.gov (United States)

Liu, Wanli; Shi, Pengjun; Chen, Qiang; Yang, Peilong; Wang, Guozeng; Wang, Yaru; Luo, Huiying; Yao, Bin

2010-09-01

A xylanase-encoding gene, xyn11F63, was isolated from Penicillium sp. F63 CGMCC1669 using degenerated polymerase chain reaction (PCR) and thermal asymmetric interlaced (TAIL)-PCR techniques. The full-length chromosomal gene consists of 724 bp, including a 73-bp intron, and encodes a 217 amino acid polypeptide. The deduced amino acid sequence of xyn11F63 shows the highest identity of 70% to the xylanase from Penicillium sp. strain 40, which belongs to glycosyl hydrolases family 11. The gene was overexpressed in Pichia pastoris, and its activity in the culture medium reached 516 U ml(-1). After purification to electrophoretic homogeneity, the enzyme showed maximal activity at pH 4.5 and 40 degrees C, was stable at acidic buffers of pH 4.5-9.0, and was resistant to proteases (proteinase K, trypsin, subtilisin A, and alpha-chymotrypsin). The specific activity, K (m), and V (max) for oat spelt xylan substrate was 7,988 U mg(-1), 22.2 mg ml(-1), and 15,105.7 micromol min(-1) mg(-1), respectively. These properties make XYN11F63 a potential economical candidate for use in feed and food industrial applications.

Effects of exogenous phytase and xylanase, individually or in combination, and pelleting on nutrient digestibility, available energy content of wheat and performance of growing pigs fed wheat-based diets.

Science.gov (United States)

Yang, Y Y; Fan, Y F; Cao, Y H; Guo, P P; Dong, B; Ma, Y X

2017-01-01

Two experiments were conducted to determine the effects of adding exogenous phytase and xylanase, individually or in combination, as well as pelleting on nutrient digestibility, available energy content of wheat and the performance of growing pigs fed wheat-based diets. In Experiment 1, forty-eight barrows with an initial body weight of 35.9±0.6 kg were randomly assigned to a 2×4 factorial experiment with the main effects being feed form (pellet vs meal) and enzyme supplementation (none, 10,000 U/kg phytase, 4,000 U/kg xylanase or 10,000 U/kg phytase plus 4,000 U/kg xylanase). The basal diet contained 97.8% wheat. Pigs were placed in metabolic cages for a 7-d adaptation period followed by a 5-d total collection of feces and urine. Nutrient digestibility and available energy content were determined. Experiment 2 was conducted to evaluate the effects of pelleting and enzymes on performance of wheat for growing pigs. In this experiment, 180 growing pigs (35.2±9.0 kg BW) were allocated to 1 of 6 treatments according to a 2×3 factorial treatment arrangement with the main effects being feed form (meal vs pellet) and enzyme supplementation (0, 2,500 or 5,000 U/kg xylanase). In Experiment 1, there were no interactions between feed form and enzyme supplementation. Pelleting reduced the digestibility of acid detergent fiber (ADF) by 6.4 percentage units (pdigestibility of energy by 0.6 percentage units (pdigestibility of crude protein by 0.5 percentage units (p = 0.07) compared with diets in mash form. The addition of phytase improved the digestibility of phosphorus (pdigestibility of crude protein by 1.0 percentage units (p = 0.09) and increased the digestibility of neutral detergent fiber (NDF) (pdigestibility of phosphorus (pdigestibility (pdigestibility but decreased ADF digestibility. Adding xylanase increased crude protein digestibility and pig performance. Phytase increased the apparent total tract digestibility of phosphorus and calcium. The combination of

Oxidoreductive Cellulose Depolymerization by the Enzymes Cellobiose Dehydrogenase and Glycoside Hydrolase 61▿†

Science.gov (United States)

Langston, James A.; Shaghasi, Tarana; Abbate, Eric; Xu, Feng; Vlasenko, Elena; Sweeney, Matt D.

2011-01-01

Several members of the glycoside hydrolase 61 (GH61) family of proteins have recently been shown to dramatically increase the breakdown of lignocellulosic biomass by microbial hydrolytic cellulases. However, purified GH61 proteins have neither demonstrable direct hydrolase activity on various polysaccharide or lignacious components of biomass nor an apparent hydrolase active site. Cellobiose dehydrogenase (CDH) is a secreted flavocytochrome produced by many cellulose-degrading fungi with no well-understood biological function. Here we demonstrate that the binary combination of Thermoascus aurantiacus GH61A (TaGH61A) and Humicola insolens CDH (HiCDH) cleaves cellulose into soluble, oxidized oligosaccharides. TaGH61A-HiCDH activity on cellulose is shown to be nonredundant with the activities of canonical endocellulase and exocellulase enzymes in microcrystalline cellulose cleavage, and while the combination of TaGH61A and HiCDH cleaves highly crystalline bacterial cellulose, it does not cleave soluble cellodextrins. GH61 and CDH proteins are coexpressed and secreted by the thermophilic ascomycete Thielavia terrestris in response to environmental cellulose, and the combined activities of T. terrestris GH61 and T. terrestris CDH are shown to synergize with T. terrestris cellulose hydrolases in the breakdown of cellulose. The action of GH61 and CDH on cellulose may constitute an important, but overlooked, biological oxidoreductive system that functions in microbial lignocellulose degradation and has applications in industrial biomass utilization. PMID:21821740

Dissection of malonyl-coenzyme A reductase of Chloroflexus aurantiacus results in enzyme activity improvement.

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Changshui Liu

Full Text Available The formation of fusion protein in biosynthetic pathways usually improves metabolic efficiency either channeling intermediates and/or colocalizing enzymes. In the metabolic engineering of biochemical pathways, generating unnatural protein fusions between sequential biosynthetic enzymes is a useful method to increase system efficiency and product yield. Here, we reported a special case. The malonyl-CoA reductase (MCR of Chloroflexus aurantiacus catalyzes the conversion of malonyl-CoA to 3-hydroxypropionate (3HP, and is a key enzyme in microbial production of 3HP, an important platform chemical. Functional domain analysis revealed that the N-terminal region of MCR (MCR-N; amino acids 1-549 and the C-terminal region of MCR (MCR-C; amino acids 550-1219 were functionally distinct. The malonyl-CoA was reduced into free intermediate malonate semialdehyde with NADPH by MCR-C fragment, and further reduced to 3HP by MCR-N fragment. In this process, the initial reduction of malonyl-CoA was rate limiting. Site-directed mutagenesis demonstrated that the TGXXXG(AX(1-2G and YXXXK motifs were important for enzyme activities of both MCR-N and MCR-C fragments. Moreover, the enzyme activity increased when MCR was separated into two individual fragments. Kinetic analysis showed that MCR-C fragment had higher affinity for malonyl-CoA and 4-time higher K cat/K m value than MCR. Dissecting MCR into MCR-N and MCR-C fragments also had a positive effect on the 3HP production in a recombinant Escherichia coli strain. Our study showed the feasibility of protein dissection as a new strategy in biosynthetic systems.

Cloning, expression, and characterization of a novel alkali-tolerant xylanase from alkaliphilic Bacillus sp. SN5.

Science.gov (United States)

Bai, Wenqin; Xue, Yanfen; Zhou, Cheng; Ma, Yanhe

2015-01-01

A xylanase gene (xyn11A) was cloned from the genomic library of alkalophilic Bacillus sp. SN5. It encoded a polypeptide of 366 amino acids, consisting of a family 11 glycoside hydrolase, a short linker region, and a family 36 carbohydrate-binding module (CBM). The intact xylanase Xyn11A and the CBM-linker-truncated Xyn11A-LC were expressed in Escherichia coli BL21 (DE3). Both purified recombinant proteins exhibited the highest activity at 55 °C. The optimal pH for Xyn11A activity was 7.5, whereas Xyn11A-LC showed a broad pH profile (>80% activity at pH 5.5-8.5) with optimal activity at pH 5.5 and 7.5-8.0. They had high alkali tolerance, retaining over 80% residual activity after preincubation at pH 8.5-11.0 at 37 °C for 1 H. Xyn11A-LC showed better thermal stability, lower affinity, and lower catalytic activity to insoluble xylan than Xyn11A, whereas its specific activity for soluble beechwood xylan (4,511.9 U/mg) was greater than that of Xyn11A (3,136.4 U/mg). These results implied that the CBM of Xyn11A could change the enzymatic properties and play a role in degrading insoluble xylan. Xyn11A-LC is a family 11 alkali-tolerant cellulase-free xylanase with high specific activity, which qualifies it as a potential candidate for industrial applications, especially in the paper industry. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Dissecting electrostatic interactions in Bacillus circulans xylanase through NMR-monitored pH titrations

Energy Technology Data Exchange (ETDEWEB)

McIntosh, Lawrence P., E-mail: mcintosh@chem.ubc.ca; Naito, Daigo; Baturin, Simon J.; Okon, Mark; Joshi, Manish D. [University of British Columbia, Department of Biochemistry and Molecular Biology, Department of Chemistry, and Michael Smith Laboratories, Life Sciences Centre (Canada); Nielsen, Jens E. [University College Dublin, School of Biomolecular and Biomedical Science, Centre for Synthesis and Chemical Biology, UCD Conway Institute (Ireland)

2011-09-15

NMR-monitored pH titration curves of proteins provide a rich source of structural and electrostatic information. Although relatively straightforward to measure, interpreting pH-dependent chemical shift changes to obtain site-specific acid dissociation constants (pK{sub A} values) is challenging. In order to analyze the biphasic titrations exhibited by the side chain {sup 13}C{sup {gamma}} nuclei of the nucleophilic Glu78 and general acid/base Glu172 in Bacillus circulans xylanase, we have revisited the formalism for the ionization equilibria of two coupled acidic residues. In general, fitting NMR-monitored pH titration curves for such a system will only yield the two macroscopic pK{sub A} values that reflect the combined effects of both deprotonation reactions. However, through the use of mutations complemented with ionic strength-dependent measurements, we are able to extract the four microscopic pK{sub Ai} values governing the branched acid/base equilibria of Glu78 and Glu172 in BcX. These data, confirmed through theoretical calculations, help explain the pH-dependent mechanism of this model GH11 xylanase by demonstrating that the kinetically determined pK{sub A} values and hence catalytic roles of these two residues result from their electrostatic coupling.

Dissecting electrostatic interactions in Bacillus circulans xylanase through NMR-monitored pH titrations

International Nuclear Information System (INIS)

McIntosh, Lawrence P.; Naito, Daigo; Baturin, Simon J.; Okon, Mark; Joshi, Manish D.; Nielsen, Jens E.

2011-01-01

NMR-monitored pH titration curves of proteins provide a rich source of structural and electrostatic information. Although relatively straightforward to measure, interpreting pH-dependent chemical shift changes to obtain site-specific acid dissociation constants (pK A values) is challenging. In order to analyze the biphasic titrations exhibited by the side chain 13 C γ nuclei of the nucleophilic Glu78 and general acid/base Glu172 in Bacillus circulans xylanase, we have revisited the formalism for the ionization equilibria of two coupled acidic residues. In general, fitting NMR-monitored pH titration curves for such a system will only yield the two macroscopic pK A values that reflect the combined effects of both deprotonation reactions. However, through the use of mutations complemented with ionic strength-dependent measurements, we are able to extract the four microscopic pK Ai values governing the branched acid/base equilibria of Glu78 and Glu172 in BcX. These data, confirmed through theoretical calculations, help explain the pH-dependent mechanism of this model GH11 xylanase by demonstrating that the kinetically determined pK A values and hence catalytic roles of these two residues result from their electrostatic coupling.

Single-step purification and characterization of an extreme halophilic, ethanol tolerant and acidophilic xylanase from Aureobasidium pullulans NRRL Y-2311-1 with application potential in the food industry.

Science.gov (United States)

Yegin, Sirma

2017-04-15

An extracellular xylanase from Aureobasidium pullulans NRRL Y-2311-1 produced on wheat bran was purified by a single-step chromatographic procedure. The enzyme had a molecular weight of 21.6kDa. The optimum pH and temperature for xylanase activity were 4.0 and 30-50°C, respectively. The enzyme was stable in the pH range of 3.0-8.0. The inactivation energy of the enzyme was calculated as 218kJmol -1 . The xylanase was ethanol tolerant and kept complete activity in the presence of 10% ethanol. Likewise, it retained almost complete activity at a concentration range of 0-20% NaCl. In general, the enzyme was resistant to several metal ions and reagents. Mg 2+ , Zn 2+ , Cu 2+ , K 1+ , EDTA and β-mercaptoethanol resulted in enhanced xylanase activity. The K m and V max values on beechwood xylan were determined to be 19.43mgml -1 and 848.4Uml -1 , respectively. The enzyme exhibits excellent characteristics and could, therefore, be a promising candidate for application in food and bio-industries. Copyright © 2016 Elsevier Ltd. All rights reserved.

Role in pathogenesis of two endo-beta-1,4-xylanase genes from the vascular wilt fungus Fusarium oxysporum.

Science.gov (United States)

Gómez-Gómez, E; Ruíz-Roldán, M C; Di Pietro, A; Roncero, M I G; Hera, C

2002-04-01

A gene, xyl4, whose predicted amino acid sequence shows significant homology with family 11 xylanases, was identified from the tomato vascular wilt fungus Fusarium oxysporum f. sp. lycopersici. Expression of xyl4 is induced on oat spelt xylan as the carbon source, subject to carbon catabolite repression and preferentially expressed at alkaline ambient pH. Transcript levels of xyl4 on an inducing carbon source are differentially regulated by the nature and concentration of the nitrogen source. As shown by RT-PCR, xyl4 is expressed by F. oxysporum during the entire cycle of infection on tomato plants. Targeted inactivation of xyl4 and of xyl3, a previously identified gene of F. oxysporum f. sp. lycopersici encoding a family 10 xylanase, had no detectable effect on virulence on tomato plants, demonstrating that both genes are not essential for pathogenicity.

Characterization of the arabinoxylan-degrading machinery of the thermophilic bacterium Herbinix hemicellulosilytica-Six new xylanases, three arabinofuranosidases and one xylosidase.

Science.gov (United States)

Mechelke, M; Koeck, D E; Broeker, J; Roessler, B; Krabichler, F; Schwarz, W H; Zverlov, V V; Liebl, W

2017-09-10

Herbinix hemicellulosilytica is a newly isolated, gram-positive, anaerobic bacterium with extensive hemicellulose-degrading capabilities obtained from a thermophilic biogas reactor. In order to exploit its potential as a source for new industrial arabinoxylan-degrading enzymes, six new thermophilic xylanases, four from glycoside hydrolase family 10 (GH10) and two from GH11, three arabinofuranosidases (1x GH43, 2x GH51) and one β-xylosidase (GH43) were selected. The recombinantly produced enzymes were purified and characterized. All enzymes were active on different xylan-based polysaccharides and most of them showed temperature-vs-activity profiles with maxima around 55-65°C. HPAEC-PAD analysis of the hydrolysates of wheat arabinoxylan and of various purified xylooligosaccharides (XOS) and arabinoxylooligosaccharides (AXOS) was used to investigate their substrate and product specificities: among the GH10 xylanases, XynB showed a different product pattern when hydrolysing AXOS compared to XynA, XynC, and XynD. None of the GH11 xylanases was able to degrade any of the tested AXOS. All three arabinofuranosidases, ArfA, ArfB and ArfC, were classified as type AXH-m,d enzymes. None of the arabinofuranosidases was able to degrade the double-arabinosylated xylooligosaccharides XA 2+3 XX. β-Xylosidase XylA (GH43) was able to degrade unsubstituted XOS, but showed limited activity to degrade AXOS. Copyright © 2017. Published by Elsevier B.V.

Xylanase and feruloyl esterase from actinomycetes cultures could enhance sugarcane bagasse hydrolysis in the production of fermentable sugars.

Science.gov (United States)

Rahmani, Nanik; Kahar, Prihardi; Lisdiyanti, Puspita; Hermiati, Euis; Lee, Jaemin; Yopi; Prasetya, Bambang; Ogino, Chiaki; Kondo, Akihiko

2018-02-23

The addition of enzymes that are capable of degrading hemicellulose has a potential to reduce the need for commercial enzymes during biomass hydrolysis in the production of fermentable sugars. In this study, a high xylanase producing actinomycete strain (Kitasatospora sp. ID06-480) and the first ethyl ferulate producing actinomycete strain (Nonomuraea sp. ID06-094) were selected from 797 rare actinomycetes, respectively, which were isolated in Indonesia. The addition (30%, v/v) of a crude enzyme supernatant from the selected strains in sugarcane bagasse hydrolysis with low-level loading (1 FPU/g-biomass) of Cellic® CTec2 enhanced both the released amount of glucose and reducing sugars. When the reaction with Ctec2 was combined with crude enzymes containing either xylanase or feruloyl esterase, high conversion yield of glucose from cellulose at 60.5% could be achieved after 72 h-saccharification.

Parthenium sp. as a plant biomass for the production of alkalitolerant xylanase from mutant Penicillium oxalicum SAUE-3.510 in submerged fermentation

International Nuclear Information System (INIS)

Dwivedi, Pallavi; Vivekanand, V.; Ganguly, Ruma; Singh, Rajesh P.

2009-01-01

The use of congress grass (Parthenium sp.) and water hyacinth (Eichhornia crassipes) as low cost raw materials for xylanase production from mutant Penicillium oxalicum SAU E -3.510 in submerged fermentation was investigated. For development of mutant from wild type P. oxalicum SA-8 ITCC 6024, a strategy of mixed mutagenesis was followed using UV-irradiation and ethidium bromide, which had resulted into 1.87 fold increases in the activity of the enzyme. For enzyme production, the fungus was cultivated in mineral medium containing congress grass as carbon source. Considerably higher levels of production (475.2 ± 6.0 IU ml -1 ) were achieved in media containing congress grass, although it was slightly less than that was obtained (488.5 ± 6.5 IU ml -1 ) in presence of commercial oat spelt xylan. This fact confirms the feasibility of using this low cost non-food resource as an alternative carbon source to save costs of the enzyme production process. Maximum xylanase activity was reported at 55 deg. C with its stability at 80 deg. C for 2 h. The highest activity of xylanase at pH 9.0 and its stability at similar pH for 24 h denote the alkalitolerant nature of enzyme

Efficient production of lignocellulolytic enzymes xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by the mutant strain Aspergillus awamori 2B.361 U2/1

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Leda Maria Fortes Gottschalk

2013-01-01

Full Text Available The production of xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by Aspergillus awamori 2B.361 U2/1, a hyper producer of glucoamylase and pectinase, was evaluated using selected conditions regarding nitrogen nutrition. Submerged cultivations were carried out at 30 ºC and 200 rpm in growth media containing 30 g wheat bran/L as main carbon source and either yeast extract, ammonium sulfate, sodium nitrate or urea, as nitrogen sources; in all cases it was used a fixed molar carbon to molar nitrogen concentration of 10.3. The use of poor nitrogen sources favored the accumulation of xylanase, β-xylosidase and ferulic acid esterase to a peak concentrations of 44,880; 640 and 118 U/L, respectively, for sodium nitrate and of 34,580, 685 and 170 U/L, respectively, for urea. However, the highest β-glucosidase accumulation of 10,470 U/L was observed when the rich organic nitrogen source yeast extract was used. The maxima accumulation of filter paper activity, xylanase, β-xylosidase, ferulic acid esterase and β-glucosidase by A. awamori 2B.361 U2/1 was compared to that produced by Trichoderma reesei Rut-C30. The level of β-glucosidase was over 17-fold higher for the Aspergillus strain, whereas the levels of xylanase and β-xylosidase were over 2-fold higher. This strain also produced ferulic acid esterase (170 U/L, which was not detected in the T. reesei culture.

Isolation, purification and characterization of xylanase produced by Arthrobacter sp. MTCC 5214 when grown in solid-state fermentation

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, R.; Bhosle, N.B.

%) fractionation, and purified to homogeneity using size exclusion and ion exchange chromatography. The molecular mass of xylanase was approx. 20 kDa. Enzyme retained 100% activity at pH 7 and 8 for 24 h. It was interesting to note that at higher pH such as 9, 10...

Trichoderma reesei xylanase 5 is defective in the reference strain QM6a but functional alleles are present in other wild-type strains.

Science.gov (United States)

Ramoni, Jonas; Marchetti-Deschmann, Martina; Seidl-Seiboth, Verena; Seiboth, Bernhard

2017-05-01

Trichoderma reesei is a paradigm for the regulation and industrial production of plant cell wall-degrading enzymes. Among these, five xylanases, including the glycoside hydrolase (GH) family 11 XYN1 and XYN2, the GH10 XYN3, and the GH30 XYN4 and XYN6, were described. By genome mining and transcriptome analysis, a further putative xylanase, encoded by xyn5, was identified. Analysis of xyn5 from the genome-sequenced reference strain T. reesei QM6a shows that it encodes a non-functional, truncated form of XYN5. However, non-truncated orthologues are present in other genome sequenced Trichoderma spp., and sequencing of xyn5 in other T. reesei wild-type isolates shows that they harbor a putative functional xyn5 allele. In silico analysis and 3D modeling revealed that the encoded XYN5 has significant structural similarities to xylanases of the GH11 family, including a GH-typical substrate binding groove and a carboxylate pair in the active site. The xyn5 of wild-type strain TUCIM1282 was recombinantly expressed in a T. reesei strain with a (hemi)cellulase-free background and the corresponding protein purified to apparent homogeneity. The pH and temperature optima and the kinetic parameters of the purified XYN5 were pH 4, 50 °C, and V max  = 2646 nkat/mg with a K m of 9.68 mg/ml. This functional xyn5 allele was used to replace the mutated version which led to an overall increase of the xylanolytic activity. These findings are of particular importance as GH11 xylanases are of high biotechnological relevance, and T. reesei is one of the main industrial producers of such lignocellulose-degrading enzymes.

Influence of organic nitrogen amendment, containing amino acids on the cellulase and xylanase, produced by Trichoderma spp. isolates

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D. Draganova

2017-09-01

Full Text Available Abstract. Cellulases and hemicellulases are amount the main hydrolytic enzymes, involved in the bioconversion of lignocellulose material by microorganisms. Filamentous fungi of the genus Trichoderma are one of the most studied and good producer of cellulases and hemicellulases. The nutrients balance, especially carbon to nitrogen ratio, is one of the main factors of the biodegradation. The ability of 37 local isolates of Trichoderma sp. to produce cellulases and xylanase were tested in solid state cultivation on wheat straw as a substrate whit two variants: 1. the straw was only moistured with destilated water (CN 80:1; 2. the C:N ratio of the straw was adjusted to 30:1 using organic nitrogen amendment. There is a significant difference in the enzymatic activity of the isolates in their cultivation on straw with CN 80 and CN 30. The highest carboxymethylcellulase (CMCase activity at CN 80 showed T1T (110.19U/ml, and in the variant at CN 30 - TD (369.07U/ml. The highest β-glucosidase activity on both variants CN 80 and CN 30 was established for TG (2743.1U/ml - 12679.9U/ml. The highest xylanase activity at CN 80 and CN 30 was measured on T4I (21311.5U/ml – 47937.5U/ml. After ONA addition, all enzymes activities have increased several times, indicating the enhancing effect of the additive. The average activity of CMCase increased 6.1 times, the average β - glucosidase activity increased 5.1 times, while the xylanase activity increased 4.9 times for all tested isolates. The increase in activity of the investigated enzymes showed different patterns.

Heterologous expression, purification, crystallization and preliminary X-ray analysis of Trichoderma reesei xylanase II and four variants

International Nuclear Information System (INIS)

Wan, Qun; Kovalevsky, Andrey; Zhang, Qiu; Hamilton-Brehm, Scott; Upton, Rosalynd; Weiss, Kevin L.; Mustyakimov, Marat; Graham, David; Coates, Leighton; Langan, Paul

2013-01-01

The wild-type protein and four active-site mutants of xylanase II from Trichoderma reesei that catalyzes the hydrolysis of glycosidic bonds in xylan have successfully been crystallized. The crystallization of several structures including ligand-free and protein ligand complexes containing the substrate (xylohexaose) or product (xylotriose) are detailed. Xylanase II from Trichoderma reesei catalyzes the hydrolysis of glycosidic bonds in xylan. Crystallographic studies of this commercially important enzyme have been initiated to investigate its reaction mechanism, substrate binding and dependence on basic pH conditions. The wild-type protein was heterologously expressed in an Escherichia coli host using the defined medium and four active-site amino acids were replaced to abolish its activity (E177Q and E86Q) or to change its pH optimum (N44D and N44H). Cation-exchange and size-exclusion chromatography were used to obtain >90% protein purity. The ligand-free proteins and variant complexes containing substrate (xylohexaose) or product (xylotriose) were crystallized in several different space groups and diffracted to high resolutions (from 1.07 to 1.55 Å)

Isothermal titration calorimetry and surface plasmon resonance allow quantifying substrate binding to different binding sites of Bacillus subtilis xylanase

DEFF Research Database (Denmark)

Cuyvers, Sven; Dornez, Emmie; Abou Hachem, Maher

2012-01-01

Isothermal titration calorimetry and surface plasmon resonance were tested for their ability to study substrate binding to the active site (AS) and to the secondary binding site (SBS) of Bacillus subtilis xylanase A separately. To this end, three enzyme variants were compared. The first...

Finding stable cellulase and xylanase: evaluation of the synergistic effect of pH and temperature.

Science.gov (United States)

Farinas, Cristiane S; Loyo, Marcel Moitas; Baraldo, Anderson; Tardioli, Paulo W; Neto, Victor Bertucci; Couri, Sonia

2010-12-31

Ethanol from lignocellulosic biomass has been recognized as one of the most promising alternatives for the production of renewable and sustainable energy. However, one of the major bottlenecks holding back its commercialization is the high costs of the enzymes needed for biomass conversion. In this work, we studied the enzymes produced from a selected strain of Aspergillus niger under solid state fermentation. The cellulase and xylanase enzymatic cocktail was characterized in terms of pH and temperature by using response surface methodology. Thermostability and kinetic parameters were also determined. The statistical analysis of pH and temperature effects on enzymatic activity showed a synergistic interaction of these two variables, thus enabling to find a pH and temperature range in which the enzymes have a higher activity. The results obtained allowed the construction of mathematical models used to predict endoglucanase, β-glucosidase and xylanase activities under different pH and temperature conditions. Optimum temperature values for all three enzymes were found to be in the range between 35°C and 60°C, and the optimum pH range was found between 4 and 5.5. The methodology employed here was very effective in estimating enzyme behavior under different process conditions. Copyright © 2010 Elsevier B.V. All rights reserved.

Evaluation of operational parameters on the precipitation of endoglucanase and xylanase produced by solid state fermentation of Aspergillus niger

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C. S. Farinas

2011-03-01

Full Text Available In order to develop cost effective processes for converting biomass into biofuels, it is essential to improve enzyme production yields, stability and specific activity. In this context, the aim of this work was to evaluate the concentration of two enzymes involved in the hydrolysis of biomass, endoglucanase and xylanase, through precipitation. Statistical experimental design was used to evaluate the influence of precipitant agent concentration (ammonium sulfate and ethanol, aging time, and temperature on enzyme activity recovery. Precipitant agent concentration and aging time showed a statistically significant effect at the 95% confidence level, on both enzyme activity recoveries. The recovery of endoglucanase with ammonium sulfate and ethanol reached values up to 65 and 61%, respectively. For xylanase, the recovery rates were lower, 27 and 25% with ammonium sulfate and ethanol, respectively. The results obtained allowed the selection of the variables relevant to improving enzyme activity recovery within operational conditions suitable for industrial applications.

Isolation, screening and characterization of a novel extracellular xylanase from Aspergillus niger (KP874102.1) and its application in orange peel hydrolysis.

Science.gov (United States)

Uday, Uma Shankar Prasad; Majumdar, Ria; Tiwari, Onkar Nath; Mishra, Umesh; Mondal, Abhijit; Bandyopadhyay, Tarun Kanti; Bhunia, Biswanath

2017-12-01

In the present work, a potent xylanase producing fungal strain Aspergillus niger (KP874102.1) was isolated through cultural and morphological observations from soil sample of Baramura forest, Tripura west, India. 28S rDNA technique was applied for genomic identification of this fungal strain. The isolated strain was found to be phylogenetically closely related to Aspergillus niger. Kinetic constants such as K m and V max for extracellular xylanase were determined using various substrate such as beech wood xylan, oat spelt xylan and CM cellulose through Lineweaver-Burk plot. K m , V max and K cat for beech wood xylan are found to be 2.89mg/ml, 2442U and 426178Umlmg -1 respectively. Crude enzyme did not show also CM cellulose activity. The relative efficiency of oat spelt xylan was found to be 0.819 with respect to beech wood xylan. After acid hydrolysis, enzyme was able to produce reducing sugar with 17.7, 35.5, 50.8 and 65% (w/w) from orange peel after 15, 30, 45 and 60min incubation with cellulase free xylanase and maximum reducing sugar formation rate was found to be 55.96μg/ml/min. Therefore, the Aspergillus niger (KP874102.1) is considered as a potential candidate for enzymatic hydrolysis of orange peel. Copyright © 2017 Elsevier B.V. All rights reserved.

Supplementation with xylanase and β-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover

Science.gov (United States)

2011-01-01

Background Hemicellulose is often credited with being one of the important physical barriers to enzymatic hydrolysis of cellulose, and acts by blocking enzyme access to the cellulose surface. In addition, our recent research has suggested that hemicelluloses, particularly in the form of xylan and its oligomers, can more strongly inhibit cellulase activity than do glucose and cellobiose. Removal of hemicelluloses or elimination of their negative effects can therefore become especially pivotal to achieving higher cellulose conversion with lower enzyme doses. Results In this study, cellulase was supplemented with xylanase and β-xylosidase to boost conversion of both cellulose and hemicellulose in pretreated biomass through conversion of xylan and xylo-oligomers to the less inhibitory xylose. Although addition of xylanase and β-xylosidase did not necessarily enhance Avicel hydrolysis, glucan conversions increased by 27% and 8% for corn stover pretreated with ammonia fiber expansion (AFEX) and dilute acid, respectively. In addition, adding hemicellulase several hours before adding cellulase was more beneficial than later addition, possibly as a result of a higher adsorption affinity of cellulase and xylanase to xylan than glucan. Conclusions This key finding elucidates a possible mechanism for cellulase inhibition by xylan and xylo-oligomers and emphasizes the need to optimize the enzyme formulation for each pretreated substrate. More research is needed to identify advanced enzyme systems designed to hydrolyze different substrates with maximum overall enzyme efficacy. PMID:21702938

Xylanase Increased the Ileal Digestibility of Non-Starch Polysaccharides and Concentration of Low Molecular Weight Non-Digestible Carbohydrates in Pigs Fed High Levels of wheat DDGS

DEFF Research Database (Denmark)

Pedersen, Mads Brøgger; Yu, Shukun; Arent, Susan

2015-01-01

The objective was to study the effect of a commercially available xylanase (CAX), an experimental xylanase (EX), and EX in combination with protease (EXP) on the degradation of nondigestible carbohydrates (NDC) and apparent ileal digestibility (AID) of nutrients in wheat distillers dried grains...... with solubles (wDDGS). The control and 3 enzyme diets contained 96% wDDGS supplemented with vitamins, minerals, l-lysine, and chromic oxide as a digestibility marker in addition to enzyme premix. Eight ileal cannulated pigs were fed 4 experimental diets containing 96% wDDGS—a control diet or 1 of 3 diets...

Production of cellulase and xylanase in a bubble gum column using immobilized Aspergillus niger KKS

Energy Technology Data Exchange (ETDEWEB)

Kang, Seong-Woo; Kim, Seung-Woo [Univ. of Suwon (Korea, Republic of); Lee, Jin-Suk [Korea Institute of Energy Research, Daejeon (Korea, Republic of)

1995-05-01

Aspergillus niger KKS, isolated from a farmland near Suwon, was immobilized on Celite and polyurethane foams. Enzyme activities produced by the immobilized cell system in a bubble column were higher than that of shake-flask culture. The enzyme productivities were twice as high. {Beta}-Glucosidase, {Beta}-xylosidase, and xylanase activities obtained in a bubble column were significant when the ground rice straw was used as a substrate. 9 refs., 2 figs., 3 tabs.

Mycoflora and mycotoxin of hazelnut (Corylus avellana L.) and walnut (Juglans regia L.) seeds in Egypt.

Science.gov (United States)

Abdel-Hafez, A I; Saber, S M

1993-03-01

Fifty-one species and 3 varieties appertaining to 20 genera were collected from 20 samples of each of hazelnut and walnut seeds on glucose- and 40% (W/V) sucrose-Czapek's agar at 25 degrees C and 45 degrees C with the most common mesophiles were Aspergillus flavus, A. fumigatus, A. niger, Cladosporium cladosporioides, C. herbarum, Penicillium chrysogenum, P. citrinum and P. oxalicum. Fusarium (represented by F. equiseti, F. moniliforme and F. oxysporum) was recovered from walnut seeds in moderate frequency (on glucose-Czapek's agar). Eurotium (E. amstelodami, E. chevalieri, E. repens and E. rubrum) was completely absent on glucose agar, but it was isolated in high frequency from the two types of seeds on 40% sucrose-Czapek's agar. Aspergillus fumigatus and Rhizomucor pusillus were the most common thermophilic fungi in hazelnut and walnut seeds on glucose agar at 45 degrees C. Humicola grisea var. themoidae and Thermoascus aurantiacus were encountered rarely from walnuts. The nuts samples were assayed for natural occurrence of aflatoxins B1, B2, G1 and G2, citrinin, ochratoxin A, patulin, sterigmatocystin, zearalenone, T-2 toxin and diacetoxyscirpenol by thin layer chromatography analysis. Aflatoxin was detected in 90% of hazelnut samples (25-175 micrograms/kg) and 75% of walnut samples (15-25 micrograms/kg). Zearalenone was detected in one sample of walnut (125 micrograms/kg). This is the first report for the presence of zearalenone in walnut. The other mycotoxins were not detected.

Parthenium sp. as a plant biomass for the production of alkalitolerant xylanase from mutant Penicillium oxalicum SAU{sub E}-3.510 in submerged fermentation

Energy Technology Data Exchange (ETDEWEB)

Dwivedi, Pallavi; Vivekanand, V.; Ganguly, Ruma; Singh, Rajesh P. [Department of Biotechnology, Indian Institute of Technology Roorkee, Roorkee 247667 (India)

2009-04-15

The use of congress grass (Parthenium sp.) and water hyacinth (Eichhornia crassipes) as low cost raw materials for xylanase production from mutant Penicillium oxalicum SAU{sub E}-3.510 in submerged fermentation was investigated. For development of mutant from wild type P. oxalicum SA-8 ITCC 6024, a strategy of mixed mutagenesis was followed using UV-irradiation and ethidium bromide, which had resulted into 1.87 fold increases in the activity of the enzyme. For enzyme production, the fungus was cultivated in mineral medium containing congress grass as carbon source. Considerably higher levels of production (475.2 {+-} 6.0 IU ml{sup -1}) were achieved in media containing congress grass, although it was slightly less than that was obtained (488.5 {+-} 6.5 IU ml{sup -1}) in presence of commercial oat spelt xylan. This fact confirms the feasibility of using this low cost non-food resource as an alternative carbon source to save costs of the enzyme production process. Maximum xylanase activity was reported at 55 C with its stability at 80 C for 2 h. The highest activity of xylanase at pH 9.0 and its stability at similar pH for 24 h denote the alkalitolerant nature of enzyme. (author)

A xylanase gene directly cloned from the genomic DNA of alkaline wastewater sludge showing application potential in the paper industry.

Science.gov (United States)

Zhao, Yanyu; Luo, Huiying; Meng, Kun; Shi, Pengjun; Wang, Guozeng; Yang, Peilong; Yuan, Tiezheng; Yao, Bin

2011-09-01

A xylanase gene, aws-2x, was directly cloned from the genomic DNA of the alkaline wastewater sludge using degenerated PCR and modified TAIL-PCR. The deduced amino acid sequence of AWS-2x shared the highest identity (60%) with the xylanase from Chryseobacterium gleum belonging to the glycosyl hydrolase GH family 10. Recombinant AWS-2x was expressed in Escherichia coli BL21 (DE3) and purified to electrophoretic homogeneity. The enzyme showed maximal activity at pH 7.5 and 55 °C, maintained more than 50% of maximal activity when assayed at pH 9.0, and was stable over a wide pH range from 4.0 to 11.0. The specific activity of AWS-2x towards hardwood xylan (beechwood and birchwood xylan) was significantly higher than that to cereal xylan (oat spelt xylan and wheat arabinoxylan). These properties make AWS-2x a potential candidate for application in the pulp and paper industry.

Cellulase and Xylanase Production by Penicillium echinulatum in Submerged Media Containing Cellulose Amended with Sorbitol

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Carla Eliana Todero Ritter

2013-01-01

Full Text Available The present work investigated the use of sorbitol as a soluble carbon source, in association with cellulose, to produce cellulases and xylanases in submerged cultures of Penicillium echinulatum 9A02S1. Because cellulose is an insoluble carbon source, in cellulase production, there are some problems with rheology and oxygen transfer. The submerged fermentations containing media composed of 0, 0.25, 0.5, 0.75, and 1% (w/v sorbitol and cellulose that were added at different times during the cultivation; 0.2% (w/v soy bran; 0.1% (w/v wheat bran; and a solution of salts. The highest filter paper activity (FPA ( IU·mL−1 was obtained on the seventh day in the medium containing 0.5% (w/v sorbitol and 0.5% (w/v cellulose added 24 h after the start of cultivation. However, the CMCases showed an activity peak on the sixth day ( IU·mL−1 in the medium containing 0.75% (w/v sorbitol and 0.75% (w/v cellulose added after 12 h of cultivation. The xylanases showed the highest activity in the medium with 0.75% (w/v sorbitol and 0.25% (w/v cellulose added 36 h after the start of cultivation. This strategy enables the reduction of the cellulose concentration, which in high concentrations can cause rheological and oxygen transfer problems.

Supplementation with xylanase and β-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover

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Qing Qing

2011-06-01

Full Text Available Abstract Background Hemicellulose is often credited with being one of the important physical barriers to enzymatic hydrolysis of cellulose, and acts by blocking enzyme access to the cellulose surface. In addition, our recent research has suggested that hemicelluloses, particularly in the form of xylan and its oligomers, can more strongly inhibit cellulase activity than do glucose and cellobiose. Removal of hemicelluloses or elimination of their negative effects can therefore become especially pivotal to achieving higher cellulose conversion with lower enzyme doses. Results In this study, cellulase was supplemented with xylanase and β-xylosidase to boost conversion of both cellulose and hemicellulose in pretreated biomass through conversion of xylan and xylo-oligomers to the less inhibitory xylose. Although addition of xylanase and β-xylosidase did not necessarily enhance Avicel hydrolysis, glucan conversions increased by 27% and 8% for corn stover pretreated with ammonia fiber expansion (AFEX and dilute acid, respectively. In addition, adding hemicellulase several hours before adding cellulase was more beneficial than later addition, possibly as a result of a higher adsorption affinity of cellulase and xylanase to xylan than glucan. Conclusions This key finding elucidates a possible mechanism for cellulase inhibition by xylan and xylo-oligomers and emphasizes the need to optimize the enzyme formulation for each pretreated substrate. More research is needed to identify advanced enzyme systems designed to hydrolyze different substrates with maximum overall enzyme efficacy.

C-Terminal carbohydrate-binding module 9_2 fused to the N-terminus of GH11 xylanase from Aspergillus niger.

Science.gov (United States)

Xu, Wenxuan; Liu, Yajuan; Ye, Yanxin; Liu, Meng; Han, Laichuang; Song, Andong; Liu, Liangwei

2016-10-01

The 9_2 carbohydrate-binding module (C2) locates natively at the C-terminus of the GH10 thermophilic xylanase from Thermotoga marimita. When fused to the C-terminus, C2 improved thermostability of a GH11 xylanase (Xyn) from Aspergillus niger. However, a question is whether the C-terminal C2 would have a thermostabilizing effect when fused to the N-terminus of a catalytic module. A chimeric enzyme, C2-Xyn, was created by step-extension PCR, cloned in pET21a(+), and expressed in E. coli BL21(DE3). The C2-Xyn exhibited a 2 °C higher optimal temperature, a 2.8-fold longer thermostability, and a 4.5-fold higher catalytic efficiency on beechwood xylan than the Xyn. The C2-Xyn exhibited a similar affinity for binding to beechwood xylan and a higher affinity for oat-spelt xylan than Xyn. C2 is a thermostabilizing carbohydrate-binding module and provides a model of fusion at an enzymatic terminus inconsistent with the modular natural terminal location.

Utilization of Bagasse Cellulose for Ethanol Production through Simultaneous Saccharification and Fermentation by Xylanase

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M Samsuri

2010-10-01

Full Text Available Bagasse is a solid residue from sugar cane process, which is not many use it for some product which have more added value. Bagasse, which is a lignosellulosic material, be able to be use for alternative energy resources like bioethanol or biogas. With renewable energy resources a crisis of energy in Republic of Indonesia could be solved, especially in oil and gas. This research has done the conversion of bagasse to bioethanol with xylanase enzyme. The result show that bagasse contains of 52,7% cellulose, 20% hemicelluloses, and 24,2% lignin. Xylanase enzyme and Saccharomyces cerevisiae was used to hydrolyse and fermentation in SSF process. Variation in this research use pH (4, 4,5, and 5, for increasing ethanol quantity, SSF process was done by added chloride acid (HCl with concentration 0.5% and 1% (v/v and also pre-treatment with white rot fungi such as Lentinus edodes (L.edodes as long 4 weeks. The SSF process was done with 24, 48, 72, and 96 hour's incubation time for fermentation. Variation of pH 4, 4,5, and 5 can produce ethanol with concentrations 2,357 g/L, 2,451 g/L, 2,709 g/L. The added chloride acid (HCl with concentration 0.5% and 1% (v/v and L. edodes can increase ethanol yield, The highest ethanol concentration with added chloride acid (HCl concentration 0.5% and 1% consecutively is 2,967 g/L, 3,249 g/L. The highest ethanol concentration with pre-treatment by L. edodes is 3,202 g/L.

Cellulase and xylanase activity during the decomposition of three aquatic macrophytes in a tropical oxbow lagoon

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L Sciessere

2011-09-01

Full Text Available Due to the connection between enzymatic activity and degradation of different fractions of organic matter, enzyme assays can be used to estimate degradation rates of particulate and dissolved organic carbon in freshwater systems. The aim of this study was to quantify and model the enzymatic degradation involving the decomposition of macrophytes, describing temporal activity of cellulases (EC 3.2.1.4 and EC 3.2.1.91 and xylanase (EC 3.2.1.8 during in situ decomposition of three aquatic macrophytes (Salvinia sp., Eichhornia azurea and Cyperus giganteus on the surface and water-sediment interface (w-s interface of an oxbow lagoon (Óleo lagoon within a natural Brazilian Savanna Reserve. Overall, the enzymatic degradation of aquatic macrophytes in Óleo lagoon occurred during the whole year and was initiated together with leaching. Xylanase production was ca. 5 times higher than cellulase values due to easy access to this compound by cellulolytic microorganisms. Enzymatic production and detritus mass decay were similar on the surface and w-s interface. Salvinia sp. was the most recalcitrant detritus, with low mass decay and enzymatic activity. E. azurea and C. giganteus decomposition rates and enzymatic production were high and similar. Due to the physicochemical homogeneity observed in the Óleo lagoon, the differences between the decay rates of each species are mostly related with detritus chemical quality.

Crystallization and preliminary X-ray study of a family 10 alkali-thermostable xylanase from alkalophilic Bacillus sp. strain NG-27

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Manikandan, K. [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India); Bhardwaj, Amit [International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067 (India); Ghosh, Amit [Institute of Microbial Technology, Sector 39-A, Chandigarh 160 036 (India); Reddy, V. S. [International Centre for Genetic Engineering and Biotechnology, New Delhi 110 067 (India); Ramakumar, S., E-mail: ramak@physics.iisc.ernet.in [Department of Physics, Indian Institute of Science, Bangalore 560 012 (India); Bioinformatics Centre, Indian Institute of Science, Bangalore 560 012 (India)

2005-08-01

A family 10 alkali-thermostable xylanase from Bacillus sp. NG-27 has been crystallized. A diffraction data set has been collected to 2.2 Å resolution. Xylanases (EC 3.2.1.8) catalyze the hydrolysis of β-1,4-glycosidic linkages within xylan, a major hemicellulose component in the biosphere. The extracellular endoxylanase (XylnA) from the alkalophilic Bacillus sp. strain NG-27 belongs to family 10 of the glycoside hydrolases. It is active at 343 K and pH 8.4. Moreover, it has attractive features from the point of view of utilization in the paper pulp, animal feed and baking industries since it is an alkali-thermostable protein. In this study, XylnA was purified from the native host source and crystallized by the hanging-drop vapour-diffusion method. The crystals belong to the monoclinic space group C2, with unit-cell parameters a = 174.5, b = 54.7, c = 131.5 Å, β = 131.2°, and diffract to better than 2.2 Å resolution.

Crystallization and preliminary X-ray study of a family 10 alkali-thermostable xylanase from alkalophilic Bacillus sp. strain NG-27

International Nuclear Information System (INIS)

Manikandan, K.; Bhardwaj, Amit; Ghosh, Amit; Reddy, V. S.; Ramakumar, S.

2005-01-01

A family 10 alkali-thermostable xylanase from Bacillus sp. NG-27 has been crystallized. A diffraction data set has been collected to 2.2 Å resolution. Xylanases (EC 3.2.1.8) catalyze the hydrolysis of β-1,4-glycosidic linkages within xylan, a major hemicellulose component in the biosphere. The extracellular endoxylanase (XylnA) from the alkalophilic Bacillus sp. strain NG-27 belongs to family 10 of the glycoside hydrolases. It is active at 343 K and pH 8.4. Moreover, it has attractive features from the point of view of utilization in the paper pulp, animal feed and baking industries since it is an alkali-thermostable protein. In this study, XylnA was purified from the native host source and crystallized by the hanging-drop vapour-diffusion method. The crystals belong to the monoclinic space group C2, with unit-cell parameters a = 174.5, b = 54.7, c = 131.5 Å, β = 131.2°, and diffract to better than 2.2 Å resolution

Robust expression and secretion of Xylanase1 in Chlamydomonas reinhardtii by fusion to a selection gene and processing with the FMDV 2A peptide.

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Beth A Rasala

Full Text Available Microalgae have recently received attention as a potential low-cost host for the production of recombinant proteins and novel metabolites. However, a major obstacle to the development of algae as an industrial platform has been the poor expression of heterologous genes from the nuclear genome. Here we describe a nuclear expression strategy using the foot-and-mouth-disease-virus 2A self-cleavage peptide to transcriptionally fuse heterologous gene expression to antibiotic resistance in Chlamydomonas reinhardtii. We demonstrate that strains transformed with ble-2A-GFP are zeocin-resistant and accumulate high levels of GFP that is properly 'cleaved' at the FMDV 2A peptide resulting in monomeric, cytosolic GFP that is easily detectable by in-gel fluorescence analysis or fluorescent microscopy. Furthermore, we used our ble2A nuclear expression vector to engineer the heterologous expression of the industrial enzyme, xylanase. We demonstrate that linking xyn1 expression to ble2A expression on the same open reading frame led to a dramatic (~100-fold increase in xylanase activity in cells lysates compared to the unlinked construct. Finally, by inserting an endogenous secretion signal between the ble2A and xyn1 coding regions, we were able to target monomeric xylanase for secretion. The novel microalgae nuclear expression strategy described here enables the selection of transgenic lines that are efficiently expressing the heterologous gene-of-interest and should prove valuable for basic research as well as algal biotechnology.

Scan-rate dependence in protein calorimetry: the reversible transitions of Bacillus circulans xylanase and a disulfide-bridge mutant.

OpenAIRE

Davoodi, J.; Wakarchuk, W. W.; Surewicz, W. K.; Carey, P. R.

1998-01-01

The stabilities of Bacillus circulans xylanase and a disulfide-bridge-containing mutant (S100C/N148C) were investigated by differential scanning calorimetry (DSC) and thermal inactivation kinetics. The thermal denaturation of both proteins was found to be irreversible, and the apparent transition temperatures showed a considerable dependence upon scanning rate. In the presence of low (nondenaturing) concentrations of urea, calorimetric transitions were observed for both proteins in the second...

Effects of diet acidification and xylanase supplementation on performance, nutrient digestibility, duodenal histology and gut microflora of broilers fed wheat based diet

NARCIS (Netherlands)

Esmaeilipour, O.; Moravej, H.; Shivazad, M.; Rezaian, M.; Aminzadeh, S.; Krimpen, van M.M.

2012-01-01

1. The objective of this experiment was to study the influences of xylanase and citric acid on the performance, nutrient digestibility, digesta viscosity, duodenal histology, and gut microflora of broilers fed on a wheat based diet. 2. The experiment was carried out as a 2 x 3 factorial arrangement

Enzymatic hydrolysis of pretreated Alfa fibers (Stipa tenacissima) using β-d-glucosidase and xylanase of Talaromyces thermophilus from solid-state fermentation.

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Mallek-Fakhfakh, Hanen; Fakhfakh, Jawhar; Walha, Kamel; Hassairi, Hajer; Gargouri, Ali; Belghith, Hafedh

2017-10-01

This work aims at realizing an optimal hydrolysis of pretreated Alfa fibers (Stipa tenacissima) through the use of enzymes produced from Talaromyces thermophilus AX4, namely β-d-glucosidase and xylanase, by a solid state fermentation process of an agro-industrial waste (wheat bran supplemented with lactose). The carbon source was firstly selected and the optimal values of three other parameters were determined: substrate loading (10g), moisture content (85%) and production time (10days); which led to an optimized enzymatic juice. The outcome was then supplemented with cellulases of T. reesei and used to optimize the enzymatic saccharification of alkali-pretreated Alfa fibers (PAF). The maximum saccharification yield of 83.23% was achieved under optimized conditions (substrate concentration 3.7% (w/v), time 144h and enzyme loading of 0.8 FPU, 15U CMCase, 60U β-d-glucosidase and 125U xylanase).The structural modification of PAF due to enzymatic saccharification was supported by the changes of morphologic and chemical composition observed through macroscopic representation, FTIR and X-Ray analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Fodder radish cake (Raphanus sativus L. as an alternative biomass for the production of cellulases and xylanases in solid-state cultivation

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L. Zukovski

Full Text Available Abstract Fodder radish (FR is an oilseed crop with a high potential for biodiesel production due to its high productivity and the quality of its seed oil. FR oil extraction results in a residue that is rich in protein and fiber. In this study, FR cake (FRC was evaluated as carbon and nitrogen source for the production of cellulases and xylanases using Penicillium echinulatum S1M29 during solid-state cultivation. It was determined that it is possible to partially replace wheat bran (WB by FRC, resulting in 24.22 ± 0.25U/g Filter Paper Activity (144 hours, 210.5 ± 5.8U/g endoglucanase activity (144 hours, 22.62 ± 0.01U/g (-glucosidase activity (96 hours and 784.7 ± 70.19U/g xylanase activity (120 hours. These values are equal or higher than the enzymatic activity obtained using WB. These results may contribute to the reduction of the cost of enzymes used in the production of cellulosic ethanol or other biotechnological applications.

Purification and characterization of endo-xylanases from aspergillus Niger. II. An enzyme of PL 45

Energy Technology Data Exchange (ETDEWEB)

Shei, J.C.; Fratzke, A.R.; Frederick, M.M.; Frederick, J.R.; Reilly, P.J.

1985-04-01

A homogeneous endo-xylanase (1,4-..beta..-D-xylan xylano-hydrolase, EC 3.2.1.8) was obtained from a crude Aspergillus niger pentosanase by chromatography with Ultrogel AcA 54, SP-Sephadex C-25 at pH 4.5, DEAE-Sephadex A-25 at pH 5.4, Sephadex G-50, and SP-Sephadex C-25 with a gradient from pH 2.8 to pH 4.6. It was much more active on soluble than on insoluble xylan yielding large amounts of unreacted xylan and a mixture of oligosaccharides with chain lengths from two to six. No xylose or L-arabinose was produced. There was high activity on a xylopentaose through xylononaose mixture, but not on xylobiose, xylotriose, or xylotetraose. The enzyme had slight activity on untreated cellulose, carboxymethylcellulose, and pectin. Molecular weight was ca. 1.4 x 10/sup 4/, with an isoelectric point of 4.5 and an amino acid profile high in acidic but low in sulfur-containing residues. In a 25-min assay at pH 4.7, this endo-xylanase was most active at 45 degrees C, with an activation energy from 5 to 35 degrees C of 33.3 kJ/mol. The optimum pH for activity was 4.9. Decay in buffer was first order, with an activation energy at pH 4.7 from 48 to 53 degrees C of 460 kJ/mol. Optimum pH for stability was about 5.6, where the half-life at 48 degrees C in buffer was ca. 40 h.

Enhancing cellulase production by overexpression of xylanase regulator protein gene, xlnR, in Talaromyces cellulolyticus cellulase hyperproducing mutant strain.

Science.gov (United States)

Okuda, Naoyuki; Fujii, Tatsuya; Inoue, Hiroyuki; Ishikawa, Kazuhiko; Hoshino, Tamotsu

2016-10-01

We obtained strains with the xylanase regulator gene, xlnR, overexpressed (HXlnR) and disrupted (DXlnR) derived from Talaromyces cellulolyticus strain C-1, which is a cellulase hyperproducing mutant. Filter paper degrading enzyme activity and cellobiohydrolase I gene expression was the highest in HXlnR, followed by C-1 and DXlnR. These results indicate that the enhancement of cellulase productivity was succeeded by xlnR overexpression.

Purification, crystallization and crystallographic analysis of Clostridium thermocellum endo-1,4-β-d-xylanase 10B in complex with xylohexaose

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Najmudin, Shabir, E-mail: shabir@dq.fct.unl.pt [REQUIMTE, Departamento de Química, FCT-UNL, 2829-516 Caparica (Portugal); Pinheiro, Benedita A. [CIISA - Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa (Portugal); Romão, Maria J. [REQUIMTE, Departamento de Química, FCT-UNL, 2829-516 Caparica (Portugal); Prates, José A. M.; Fontes, Carlos M. G. A., E-mail: shabir@dq.fct.unl.pt [CIISA - Faculdade de Medicina Veterinária, Universidade Técnica de Lisboa, Avenida da Universidade Técnica, 1300-477 Lisboa (Portugal); REQUIMTE, Departamento de Química, FCT-UNL, 2829-516 Caparica (Portugal)

2008-08-01

The N-terminal moiety of C. thermocellum endo-1,4-β-d-xylanase 10B, comprising a carbohydrate-binding module (CBM22-1) and a GH10 E337A mutant domain, has been crystallized in complex with xylohexaose. The crystals belong to the trigonal space group P3{sub 2}21, contain a dimer in the asymmetric unit and diffract to beyond 2.0 Å resolution. The cellulosome of Clostridium thermocellum is a highly organized multi-enzyme complex of cellulases and hemicellulases involved in the hydrolysis of plant cell-wall polysaccharides. The bifunctional multi-modular xylanase Xyn10B is one of the hemicellulase components of the C. thermocellum cellulosome. The enzyme contains an internal glycoside hydrolase family 10 catalytic domain (GH10) and a C-terminal family 1 carbohydrate esterase domain (CE1). The N-terminal moiety of Xyn10B (residues 32–551), comprising a carbohydrate-binding module (CBM22-1) and the GH10 E337A mutant, was crystallized in complex with xylohexaose. The crystals belong to the trigonal space group P3{sub 2}21 and contain a dimer in the asymmetric unit. The crystals diffracted to beyond 2.0 Å resolution.

Prediction of ingredient quality and the effect of a combination of xylanase, amylase, protease and phytase in the diets of broiler chicks. 2. Energy and nutrient utilisation.

Science.gov (United States)

Cowieson, A J; Singh, D N; Adeola, O

2006-08-01

1. In order to investigate the effects of xylanase, amylase, protease and phytase in the diets of broiler chickens containing graded concentrations of metabolisable energy (ME), two 42-d experiments were conducted using a total of 2208 broiler chicks (8 treatments with 12 replicate pens in each experiment). 2. Four diets including one positive and three negative control diets were used. Three maize/soybean meal-based negative control (NC) diets were formulated to be identical in available phosphorus (P), calcium (Ca) and amino acids but NC1 contained approximately 0.17 MJ/kg less ME than NC2 and approximately 0.34 MJ/kg less ME than NC3. A positive control (PC) was fed for comparison and was formulated to be adequate in all nutrients, providing approximately 0.63 MJ/kg ME, 0.13% available P, 0.12% Ca and 1 to 2% amino acids more than NC1. 3. The reduction in nutrient density between NC1 and PC was determined using ingredient quality models Avichecktrade mark Corn and Phychecktrade mark that can predict the response to exogenous enzymes in maize/soybean meal-based broiler diets. Supplementation of each diet with or without a cocktail of xylanase, amylase, protease and phytase gave a total of 8 dietary treatments in a 4 x 2 factorial arrangement. The same treatments and diet designs were used in both experiments but conducted in different locations using different batches of maize, soybean meal and minor ingredients. 4. In both experiments, digestibility was improved by the addition of exogenous enzymes, particularly those for P, Ca and certain amino acids. In addition, the supplementation of the PC with enzymes elicited a positive response indicating that over-the-top addition of xylanase, amylase, protease and phytase may offer a nutritionally and economically viable alternative to feed cost reduction. 5. It can be concluded that the digestibility of nutrients by broilers fed on maize/soybean meal-based diets can be improved by the use of a combination of xylanase

First detection in the USA: new plant pathogen, Phytophthora tentaculata, in native plant nurseries and restoration sites in California

Science.gov (United States)

S. Rooney-Latham; C. L. Blomquist; T. Swiecki; E. Bernhardt; S.J. Frankel

2015-01-01

Phytophthora tentaculata Kröber & Marwitz, has been detected in several native plant nurseries in 4 California counties and in restoration sites on orange sticky monkey flower (Diplacus aurantiacus subsp. aurantiacus (W. Curtis) Jeps. [Scrophulariaceae]), toyon (Heteromeles...

Production of spent mushroom substrate hydrolysates useful for cultivation of Lactococcus lactis by dilute sulfuric acid, cellulase and xylanase treatment.

Science.gov (United States)

Qiao, Jian-Jun; Zhang, Yan-Fei; Sun, Li-Fan; Liu, Wei-Wei; Zhu, Hong-Ji; Zhang, Zhijun

2011-09-01

Spent mushroom substrate (SMS) was treated with dilute sulfuric acid followed by cellulase and xylanase treatment to produce hydrolysates that could be used as the basis for media for the production of value added products. A L9 (3(4)) orthogonal experiment was performed to optimize the acid treatment process. Pretreatment with 6% (w/w) dilute sulfuric acid at 120°C for 120 min provided the highest reducing sugar yield of 267.57 g/kg SMS. No furfural was detected in the hydrolysates. Exposure to 20PFU of cellulase and 200 XU of xylanase per gram of pretreated SMS at 40°C resulted in the release of 79.85 g/kg or reducing sugars per kg acid pretreated SMS. The dilute sulfuric acid could be recycled to process fresh SMS four times. SMS hydrolysates neutralized with ammonium hydroxide, sodium hydroxide, or calcium hydroxide could be used as the carbon source for cultivation of Lactococcus lactis subsp. lactis W28 and a cell density of 2.9×10(11)CFU/mL could be obtained. The results provide a foundation for the development of value-added products based on SMS. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of xylanase and citric acid on the performance, nutrient retention, and characteristics of gastrointestinal tract of broilers fed low-phosphorus wheat-based diets

NARCIS (Netherlands)

Esmaeilipour, O.; Shivazad, M.; Moravej, H.; Aminzadeh, S.; Rezaian, M.; Krimpen, van M.M.

2011-01-01

An experiment was conducted to study the effects of xylanase and citric acid on the performance, nutrient retention, jejunal viscosity, and size and pH of the gastrointestinal tract of broilers fed a low-P wheat-based diet. The experiment was conducted as a 2 × 3 factorial arrangement with 2 levels

THE INFLUENCE OF ASOCIATED SUPPLEMENT OF ALFA AMYLASE AND XYLANASE ON THE RHEOLOGY OF DOUGH CONCEARNING ITS CONSTITOGRAPHICAL PARAMETERS

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RODICA CHEREJI

2009-05-01

Full Text Available In this paper we determined the influence of associated supplement of alfa amylase and xylanase on the rheology of dough concearning its constitographical parameters : maximum pressure (Pr max, (mb and the absorbed water (Wa, %. The analysis on the consistograph were conducted for constant hydration at the consistency of 500 UF. Determinations were made on 4 types of flour and optimal dosages were found for each enzyme, after which we prepared the optimal dosage of the enzymes in the compund for flour F1 and F2 : P1-840000 U. SKB/100 kg flour +8100 U. FXU /100 kg flour, P2-840000 U. SKB/100 kg flour+16200 U. FXU, /100 kg flour , P3-840000 U. SKB/100 kg flour+24300 U. FXU/100 kg flour , and for F3 and F4 thus: P1-280000 U. SKB/100 kg flour +8100 U. FXU /100 kg flour, P2- 280000 U. SKB/100 kg flour+16200 U. FXU/100 kg flour, P3-280000 U. SKB/100 kg flour+24300 U. FXU/100 kg flour. Fungous α-amylase and xylanase were used in these concentrations to establish which one is more apropriate to be added in flour to obtain superior quality of bread: finer texture of the crumb, prolongation of the freashness of the bread, improvind the colour and flavour, emproving the slicing ability.

Xylanase Production from Trichoderma harzianum 1073 D3 with Alternative Carbon and Nitrogen Sources

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Isil Seyis

2005-01-01

Full Text Available The effect of some natural wastes (orange pomace, orange peel, lemon pomace, lemon peel, apple pomace, pear peel, banana peel, melon peel and hazelnut shell on the production of xylanase from Trichoderma harzianum 1073 D3 has been studied and maximum activity has been observed on melon peel (26.5 U/mg of protein followed by apple pomace and hazelnut shell. Also, molasses could be used as an additional carbon source as it decreased the production time approximately by 50 %. Finally, potential alternatives of organic nitrogen source (cotton leaf and soybean residue wastes were analyzed and it was concluded that peptone could be replaced with these residues especially when economics of the process is the major objective.

Effect of penicillium mutation by UV and gamma radiation on xylanase production

International Nuclear Information System (INIS)

Bakri, Y.; Shamma, M.; Hammoudeh, A.; Sharabi, N.

2007-07-01

Many microorganisms produce enzymes which have importance in industrial processes. Usually this production, is not sufficient for these needs at economical level. The bioindustry concentrates on increasing the production of these enzymes. This leads to the progress of this kind of industry, which use different biotechnology means, for example mutation and screening to choice more potent strain. In this study Ultra Violet and Gamma irradiation conducted on Penicillium canescen in order to produce new mutant strains, have the ability to produce more xylanase enzyme for industrial uses. Ultra Violet irradiation enable to select five mutant strains having more enzyme production ability. The best mutant strain PCUV12 (159 unit/ml) was 40% higher than the mother strain, at the dose 150.72 j/cm 2 . Gamma radiation produced new mutant strain PCGR6 which produced 26% more enzyme than the mother strain at dose 250 Gy.(author)

Engineering better biomass-degrading ability into a GH11 xylanase using a directed evolution strategy

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Song Letian

2012-01-01

Full Text Available Abstract Background Improving the hydrolytic performance of hemicellulases on lignocellulosic biomass is of considerable importance for second-generation biorefining. To address this problem, and also to gain greater understanding of structure-function relationships, especially related to xylanase action on complex biomass, we have implemented a combinatorial strategy to engineer the GH11 xylanase from Thermobacillus xylanilyticus (Tx-Xyn. Results Following in vitro enzyme evolution and screening on wheat straw, nine best-performing clones were identified, which display mutations at positions 3, 6, 27 and 111. All of these mutants showed increased hydrolytic activity on wheat straw, and solubilized arabinoxylans that were not modified by the parental enzyme. The most active mutants, S27T and Y111T, increased the solubilization of arabinoxylans from depleted wheat straw 2.3-fold and 2.1-fold, respectively, in comparison to the wild-type enzyme. In addition, five mutants, S27T, Y111H, Y111S, Y111T and S27T-Y111H increased total hemicellulose conversion of intact wheat straw from 16.7%tot. xyl (wild-type Tx-Xyn to 18.6% to 20.4%tot. xyl. Also, all five mutant enzymes exhibited a better ability to act in synergy with a cellulase cocktail (Accellerase 1500, thus procuring increases in overall wheat straw hydrolysis. Conclusions Analysis of the results allows us to hypothesize that the increased hydrolytic ability of the mutants is linked to (i improved ligand binding in a putative secondary binding site, (ii the diminution of surface hydrophobicity, and/or (iii the modification of thumb flexibility, induced by mutations at position 111. Nevertheless, the relatively modest improvements that were observed also underline the fact that enzyme engineering alone cannot overcome the limits imposed by the complex organization of the plant cell wall and the lignin barrier.

Thermophilic fungi as new sources for production of cellulases and xylanases with potential use in sugarcane bagasse saccharification.

Science.gov (United States)

de Cassia Pereira, J; Paganini Marques, N; Rodrigues, A; Brito de Oliveira, T; Boscolo, M; da Silva, R; Gomes, E; Bocchini Martins, D A

2015-04-01

To obtain new cellulases and xylanases from thermophilic fungi; evaluate their potential for sugarcane bagasse saccharification. Thirty-two heat-tolerant fungi were isolated from the environment, identified (morphological/molecular tools) and the production of the enzymes was evaluated by solid state fermentation using lignocellulosic materials as substrates. Myceliophthora thermophila JCP 1-4 was the best producer of endoglucanase (357·51 U g(-1) ), β-glucosidase (45·42 U g(-1) ), xylanase (931·11 U g(-1) ) and avicelase (3·58 U g(-1) ). These enzymes were most active at 55-70°C and stable at 30-60°C. Using crude enzymatic extract from M. thermophila JCP 1-4 to saccharify sugarcane bagasse pretreated with microwaves and glycerol, glucose and xylose yields obtained were 15·6 and 35·13% (2·2 and 1·95 g l(-1) ), respectively. All isolated fungi have potential to produce the enzymes; M. thermophila JCP 1-4 enzymatic extract have potential to be better explored in saccharification experiments. Pretreatment improved enzymatic saccharification, as sugar yields were much higher than those obtained from in natura bagasse. Myceliophthora thermophila JCP 1-4 produces avicelase (not commonly found among fungi; important to hydrolyse crystalline cellulose) and a β-glucosidase resistant to glucose inhibition, interesting characteristics for saccharification experiments. © 2015 The Society for Applied Microbiology.

Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm.

Science.gov (United States)

Harholt, Jesper; Bach, Inga C; Lind-Bouquin, Solveig; Nunan, Kylie J; Madrid, Susan M; Brinch-Pedersen, Henrik; Holm, Preben B; Scheller, Henrik V

2010-04-01

Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm-specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal (Lys-Asp-Glu-Leu) KDEL were used. Transgenic plants were recovered in all four cases but no qualitative differences could be observed whether KDEL was added or not. Endo-xylanase activity in transgenic grains was increased between two and threefold relative to wild type. The grains were shrivelled and had a 25%-33% decrease in mass. Extensive analysis of the cell walls showed a 10%-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water-extractable arabinoxylan, and a shift in the MW of the water-extractable arabinoxylan from being mainly larger than 85 kD to being between 2 and 85 kD. Ferulic acid esterase-expressing grains were also shrivelled, and the seed weight was decreased by 20%-50%. No ferulic acid esterase activity could be detected in wild-type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15%-40% increase in water-unextractable arabinoxylan and a decrease in monomeric ferulic acid between 13% and 34%. In all the plants, the observed changes are consistent with a plant response that serves to minimize the effect of the heterologously expressed enzymes by increasing arabinoxylan biosynthesis and cross-linking.

Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm

Energy Technology Data Exchange (ETDEWEB)

Harholt, Jesper; Bach, Inga C; Lind-Bouquin, Solveig; Nunan, Kylie J.; Madrid, Susan M.; Brinch-Pedersen, Henrik; Holm, Preben B.; Scheller, Henrik V.

2009-12-08

Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal KDEL were used. Transgenic plants were recovered in all four cases but no qualitative differences could be observed whether KDEL was added or not. Endo-xylanase activity in transgenic grains was increased between two and three fold relative to wild type. The grains were shriveled and had a 25-33% decrease in mass. Extensive analysis of the cell walls showed a 10-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water extractable arabinoxylan, and a shift in the MW of the water extractable arabinoxylan from being mainly larger than 85 kD to being between 2 kD and 85 kD. Ferulic acid esterase expressing grains were also shriveled and the seed weight was decreased by 20-50%. No ferulic acid esterase activity could be detected in wild type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15-40% increase in water unextractable arabinoxylan and a decrease in monomeric ferulic acid between 13 and 34%. In all the plants the observed changes are consistent with a plant response that serves to minimize the effect of the heterologously expressed enzymes by increasing arabinoxylan biosynthesis and cross-linking.

Concomitant production of cellulase and xylanase by thermophilic mould Sporotrichum thermophile in solid state fermentation and their applicability in bread making.

Science.gov (United States)

Bala, Anju; Singh, Bijender

2017-06-01

Sporotrichum thermophile BJAMDU5 secreted high titres of xylanolytic and cellulolytic enzymes in solid state fermentation using mixture of wheat straw and cotton oil cake (ratio 1:1) at 45 °C, pH 5.0 after 72 h inoculated with 2.9 × 10 7  CFU/mL conidiospores. Supplementation of solid medium with lactose and ammonium sulphate further enhanced the production of hydrolytic enzymes. Among different surfactants studied, Tween 80 enhanced the production of all enzymes [3455 U/g DMR (dry mouldy residue), 879.26 U/g DMR, 976.28 U/g DMR and 35.10 U/g DMR for xylanase, CMCase (Carboxymethylcellulase), FPase (Filter paper activity) and β-glucosidase, respectively] as compared to other surfactants. Recycling of solid substrate reduced the production of all these enzymes after second cycle. End products analysis by TLC showed the ability of hydrolytic enzymes of S. thermophile to liberate monomeric (xylose and glucose) as well as oligomeric (xylobiose, cellobiose and higher ones) sugars. Supplementation of enzyme resulted in improved nutritional properties of the bread. Formation of oligomeric sugars by xylanase enzyme of S. thermophile BJAMDU5 make it a good candidate in food industry.

Thermostable endoglucanases in the liquefaction of hydrothermally pretreated wheat straw

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Siika-aho Matti

2011-01-01

Full Text Available Abstract Background Thermostable enzymes have several benefits in lignocellulose processing. In particular, they potentially allow the use of increased substrate concentrations (because the substrate viscosity decreases as the temperature increases, resulting in improved product yields and reduced capital and processing costs. A short pre-hydrolysis step at an elevated temperature using thermostable enzymes aimed at rapid liquefaction of the feedstock is seen as an attractive way to overcome the technical problems (such as poor mixing and mass transfer properties connected with high initial solid loadings in the lignocellulose to ethanol process. Results The capability of novel thermostable enzymes to reduce the viscosity of high-solid biomass suspensions using a real-time viscometric measurement method was investigated. Heterologously expressed enzymes from various thermophilic organisms were compared for their ability to liquefy the lignocellulosic substrate, hydrothermally pretreated wheat straw. Once the best enzymes were identified, the optimal temperatures for these enzymes to decrease substrate viscosity were compared. The combined hydrolytic properties of the thermostable preparations were tested in hydrolysis experiments. The studied mixtures were primarily designed to have good liquefaction potential, and therefore contained an enhanced proportion of the key liquefying enzyme, EGII/Cel5A. Conclusions Endoglucanases were shown to have a superior ability to rapidly reduce the viscosity of the 15% (w/w; dry matter hydrothermally pretreated wheat straw. Based on temperature profiling studies, Thermoascus aurantiacus EGII/Cel5A was the most promising enzyme for biomass liquefaction. Even though they were not optimized for saccharification, many of the thermostable enzyme mixtures had superior hydrolytic properties compared with the commercial reference enzymes at 55°C.

Production of xylooligosaccharides from forest waste by membrane separation and Paenibacillus xylanase hydrolysis

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Chun-Han Ko

2013-02-01

Full Text Available Xylooligosaccharides (XO, derived from the alkaline (NaOH extractant of Mikania micrantha, were produced using multiple staged membrane separation and enzymatic xylanolysis. Staged nanofiltration (NMX, ultrafiltration (EUMX, and centrifugation (EMX processes for the ethanol precipitates were conducted. NMX recovered 97.26% of total xylose and removed 73.18% of sodium ions. Concentrations of total xylose were raised from 10.98 to 51.85 mg/mL by the NMX process. Recovered xylan-containing solids were hydrolyzed by the recombinant Paenibacillus xylanase. 68% XO conversions from total xylose of NMX was achieved in 24 hours. Xylopentaose (DP 5 was the major product from NMX and EMX hydrolysis. Xylohexaose (DP 6 was the major product from EUMX hydrolysis. Results of the present study suggest the applicability for XO production by nanofiltration, as NMX gave higher XO yields compared to those from a conventional ethanol-related lignocellulosic waste conversion process.

Biological synthesis of Au nanoparticles using liquefied mash of cassava starch and their functionalization for enhanced hydrolysis of xylan by recombinant xylanase.

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Zeng, Sumei; Du, Liangwei; Huang, Meiying; Feng, Jia-Xun

2016-05-01

Au nanoparticles (AuNPs) have shown the potential for a variety of applications due to their unique physical and chemical properties. In this study, a facile and affordable method for the synthesis of AuNPs via the liquefied mash of cassava starch has been described and the functionalized AuNPs by L-cysteine improved activity of recombinant xylanase was demonstrated. UV-Vis absorption spectroscopy, transmission electron microscopy, and zeta potential measurements were performed to characterize the AuNPs and monitor their synthesis. The presence of Au was confirmed by energy-dispersive X-ray spectroscopy (EDX) and the X-ray diffraction patterns showed that Au nanocrystals were face-centered cubic. The C=O stretching vibration in the Fourier transform infrared spectrum of AuNPs suggested that the hemiacetal C-OH of sugar molecules performed the reduction of Au³⁺ to Au⁰. The presence of C and O in the EDX spectrum and the negative zeta potential of AuNPs suggested that the biomolecules present in liquefied cassava mash were responsible for the stabilization of AuNPs. The surface of AuNPs was easily functionalized by L-cysteine, which improved the stability of AuNPs. Moreover, cysteine-functionalized AuNPs could significantly improve recombinant xylanase efficiency and stability.

Response surface methodology optimization of partitioning of xylanase form Aspergillus Niger by metal affinity polymer-salt aqueous two-phase systems.

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Fakhari, Mohamad Ali; Rahimpour, Farshad; Taran, Mojtaba

2017-09-15

Aqueous two phase affinity partitioning system using metal ligands was applied for partitioning and purification of xylanase produced by Aspergillus Niger. To minimization the number of experiments for the design parameters and develop predictive models for optimization of the purification process, response surface methodology (RSM) with a face-centered central composite design (CCF) has been used. Polyethylene glycol (PEG) 6000 was activated using epichlorohydrin, covalently linked to iminodiacetic acid (IDA), and the specific metal ligand Cu was attached to the polyethylene glycol-iminodiacetic acid (PEG-IDA). The influence of some experimental variables such as PEG (10-18%w/w), sodium sulfate (8-12%), PEG-IDA-Cu 2+ concentration (0-50% w/w of total PEG), pH of system (4-8) and crude enzyme loading (6-18%w/w) on xylanase and total protein partitioning coefficient, enzyme yield and enzyme specific activity were systematically evaluated. Two optimal point with high enzyme partitioning factor 10.97 and yield 79.95 (including 10% PEG, 12% Na 2 SO 4 , 50% ligand, pH 8 and 6% crude enzyme loading) and high specific activity in top phase 42.21 (including 14.73% PEG, 8.02% Na 2 SO 4 , 28.43% ligand, pH 7.7 and 6.08% crude enzyme loading) were attained. The adequacy of the RSM models was verified by a good agreement between experimental and predicted results. Copyright © 2017 Elsevier B.V. All rights reserved.

Potential application of waste from castor bean (Ricinus communis L.) for production for xylanase of interest in the industry.

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Herculano, Polyanna Nunes; Moreira, Keila Aparecida; Bezerra, Raquel Pedrosa; Porto, Tatiana Souza; de Souza-Motta, Cristina Maria; Porto, Ana Lúcia Figueiredo

2016-12-01

Xylanases activity (XY) from Aspergillus japonicus URM5620 produced by Solid-State Fermentation (SSF) of castor press cake (Ricinus communis) on different conditions of production and extraction by PEG/citrate aqueous two-phase system (ATPS) were investigated. XY production was influenced by substrate amount (5-10 g), initial moisture (15-35 %), pH (4.0-6.0) and temperature (25-35 °C), obtaining the maximum activity of 29,085 ± 1808 U g ds -1 using 5.0 g of substrate with initial moisture of 15 % at 25 °C and pH 6.0, after 120 h of fermentation. The influence of PEG molar mass (1000-8000 g mol -1 ), phase concentrations (PEG 20.0-24.0 % w/w and sodium citrate 15-20 % w/w) and pH (6.0-8.0) on partition coefficient, purification factor, yield and selectivity of XY were determinate. Enzyme partitioning into the PEG rich phase was favored by M PEG 8000 (g mol -1 ), C PEG 24 % (w/w), C C 20 % (w/w) and pH 8.0, resulting in partition coefficient of 50.78, activity yield of 268 %, 7.20-fold purification factor and selectivity of 293. A. japonicus URM5620 has a potential role in the development of a bioprocess for the XY production using low-cost media. In addition, the present study proved it is feasible to extract xylanase from SSF by adopting the one step ATPS consisting of PEG/citrate.

EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2014. Scientific Opinion on xylanase from a genetically modified strain of Aspergillus oryzae (strain NZYM-FB)

DEFF Research Database (Denmark)

Poulsen, Morten; Binderup, Mona-Lise; Hallas-Møller, Torben

. The xylanase is intended to be used in a number of food manufacturing processes, such as starch processing, beverage alcohol (distilling), brewing, baking and other cereal based processes. The dietary exposure was assessed according to the Budget method. The food enzyme did not induce gene mutations...

On the sensitivity of protein data bank normal mode analysis: an application to GH10 xylanases

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Tirion, Monique M.

2015-12-01

Protein data bank entries obtain distinct, reproducible flexibility characteristics determined by normal mode analyses of their three dimensional coordinate files. We study the effectiveness and sensitivity of this technique by analyzing the results on one class of glycosidases: family 10 xylanases. A conserved tryptophan that appears to affect access to the active site can be in one of two conformations according to x-ray crystallographic electron density data. The two alternate orientations of this active site tryptophan lead to distinct flexibility spectra, with one orientation thwarting the oscillations seen in the other. The particular orientation of this sidechain furthermore affects the appearance of the motility of a distant, C terminal region we term the mallet. The mallet region is known to separate members of this family of enzymes into two classes.

On the sensitivity of protein data bank normal mode analysis: an application to GH10 xylanases

International Nuclear Information System (INIS)

Tirion, Monique M

2015-01-01

Protein data bank entries obtain distinct, reproducible flexibility characteristics determined by normal mode analyses of their three dimensional coordinate files. We study the effectiveness and sensitivity of this technique by analyzing the results on one class of glycosidases: family 10 xylanases. A conserved tryptophan that appears to affect access to the active site can be in one of two conformations according to x-ray crystallographic electron density data. The two alternate orientations of this active site tryptophan lead to distinct flexibility spectra, with one orientation thwarting the oscillations seen in the other. The particular orientation of this sidechain furthermore affects the appearance of the motility of a distant, C terminal region we term the mallet. The mallet region is known to separate members of this family of enzymes into two classes. (paper)

Improving the performance of dairy cattle with a xylanase-rich exogenous enzyme preparation.

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Romero, J J; Macias, E G; Ma, Z X; Martins, R M; Staples, C R; Beauchemin, K A; Adesogan, A T

2016-05-01

The objective of this experiment was to examine effects of adding 2 exogenous fibrolytic enzymes (EFE) to the total mixed ration (TMR) on the performance of lactating dairy cows (experiment 1) and the kinetics of ruminal degradation of the diet (experiment 2). Twelve EFE had been screened in a series of in vitro assays that identified the most potent EFE and their optimal doses for increasing the digestibility of bermudagrass. In experiment 1, 66 Holstein cows (21±5 d in milk) were grouped by previous milk production and parity (45 multiparous and 21 primiparous) and assigned randomly to 1 of the following 3 treatments: (1) control (CON, untreated), (2) Xylanase Plus [2A, 1mL/kg of TMR dry matter (DM); Dyadic International, Jupiter, FL], and (3) a 75:25 (vol/vol) mixture of Cellulase Plus and Xylanase Plus EFE (3A, 3.4mL/kg of TMR DM; Dyadic International). The EFE were sprayed twice daily onto a TMR (10% bermudagrass silage, 35% corn silage, 5% alfalfa-orchardgrass hay mixture, and 50% concentrates; DM basis) and fed for a 14-d training and covariate period and a 70-d measurement period. Experiment 2 aimed to examine the in situ DM ruminal degradability and ruminal fermentation measurements of the diets fed in experiment 1. Three ruminally fistulated lactating Holstein cows were assigned to the diets. The experiment had a 3×3 Latin square design with 23-d periods. In experiment 1, application of 2A increased intakes (kg/d) of DM (23.5 vs. 22.6), organic matter (21.9 vs. 20.9), and crude protein (3.9 vs. 3.7) and tended to increase yields (kg/d) of fat-corrected milk (41.8 vs. 40.7) and milk fat (1.48 vs. 1.44). In particular, 2A increased milk yield (kg/d) during wk 3 (41.2 vs. 39.8, tendency), 6 (41.9 vs. 40.1), and 7 (42.1 vs. 40.4), whereas 3A increased milk yield (kg/d) during wk 6 (41.5 vs. 40.1, tendency), 8 (41.8 vs. 40.0), and 9 (40.9 vs. 39.5, tendency). In experiment 2, EFE treatment did not affect ruminal DM degradation kinetics or ruminal pH, ammonia

Production of Cellulases, Xylanase, Pectinase, alpha-amylase and Protease Enzymes Cocktail by Bacillus spp. and Their Mixed Cultures with Candida tropicalis and Rhodotorula glutinis under Solid State Fermentation

International Nuclear Information System (INIS)

El-Batal, A.I.; Abo-State, M.A.

2006-01-01

A group of twelve locally isolated Bacillus species, B.megaterium (MAI and MA II), B.licheniformis (MLI and ML II); B. circulans, B. stearothermophilis, B.cereus, B.sphaericus, B. pumilus, B. laterosporus, B. coagulans and B. pantothenticus, were examined for the production of cellulases, xylanase, pectinase, alpha-amylase and protease enzymes cocktail on wheat bran under solid state fermentation (SSF). All species were found to be potent hydrolyzing enzymes producers and the superior producing species were B. megaterium MAI and B. licheniformis. On the other hand, both of them still produced highest enzyme titres when mixed with Candida tropicalis or Rhodotorula glutinis, yeast strains. The two superior bacterial strains produced the highest enzymatic activities when coculturing with C. tropicalis compared with coculturing with R. glutinis only or with both C. tropicalis and R. glutinis in combination. The inferior activities of cocultures (B. megaterinm MAI and R. glutinis) were enhanced in carboxymethyl cellulase (CMCase), filter paper cellulase (FPase), avecilase, xylanase, pectinase, -amylase and protease by gamma irradiation at dose 1.0 kGy with percent increase 8 %, 20 %, 10 %, 4 %, 31 %, 22 % and 34 %, respectively as compared with un-irradiated cocultures

Biosynthesis, purification and characterization of endoglucanase from a xylanase producing strain Aspergillus niger B03

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Georgi Todorov Dobrev

2012-03-01

Full Text Available An extracellular endoglucanase was isolated from the culture liquid of xylanase producing strain Aspergillus niger B03. The enzyme was purified to a homogenous form, using consecutive ultrafiltration, anion exchange chromatography, and gel filtration. Endoglucanase was a monomer protein with a molecular weight of 26,900 Da determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and 28,800 Da determined by gel filtration. The optimal pH and temperature values for the enzyme action were 3.5 and 65ºC respectively. Endoglucanase was stable at 40ºC, pH 3.0 for 210 min. The substrate specificity of the enzyme was determined with carboxymethyl cellulose, filter paper, and different glycosides. Endoglucanase displayed maximum activity in the case of carboxymethyl cellulose, with a Km value of 21.01 mg/mL. The substrate specificity and the pattern of substrate degradation suggested that the enzyme is an endoglucanase. Endoglucanase showed a synergism with endoxylanase in corn cobs hydrolysis.

Continuous xylanase production with Aspergillus nidulans under pyridoxine limitation using a trickle bed reactor.

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Müller, Michael; Prade, Rolf A; Segato, Fernando; Atiyeh, Hasan K; Wilkins, Mark R

2015-01-01

A trickle bed reactor (TBR) with recycle was designed and tested using Aspergillus nidulans with a pyridoxine marker and over-expressing/secreting recombinant client xylanase B (XynB). The pyridoxine marker prevented the fungus from synthesizing its own pyridoxine and fungus was unable to grow when no pyridoxine was present in the medium; however, enzyme production was unaffected. Uncontrolled mycelia growth that led to clogging of the TBR was observed when fungus without a pyridoxine marker was used for XynB production. Using the fungus with pyridoxine marker, the TBR was operated continuously for 18 days and achieved a XynB output of 41 U/ml with an influent and effluent flow rate of 0.5 ml/min and a recycle flow rate of 56 ml/min. Production yields in the TBR were 1.4 times greater than a static tray culture and between 1.1 and 67 times greater than yields for SSF enzyme production stated in the literature. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of Different Pretreatment of Sugar Cane Bagasse on Cellulase and Xylanases Production by the Mutant Penicillium echinulatum 9A02S1 Grown in Submerged Culture

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Marli Camassola

2014-01-01

Full Text Available The main limitation to the industrial scale hydrolysis of cellulose is the cost of cellulase production. This study evaluated cellulase and xylanase enzyme production by the cellulolytic mutant Penicillium echinulatum 9A02S1 using pretreated sugar cane bagasse as a carbon source. Most cultures grown with pretreated bagasse showed similar enzymatic activities to or higher enzymatic activities than cultures grown with cellulose or untreated sugar cane bagasse. Higher filter paper activity (1.253 ± 0.147 U·mL−1 was detected in the medium on the sixth day of cultivation when bagasse samples were pretreated with sodium hydroxide, hydrogen peroxide, and anthraquinone. Endoglucanase enzyme production was also enhanced by pretreatment of the bagasse. Nine cultures grown with bagasse possessed higher β-glucosidase activities on the sixth day than the culture grown with cellulose. The highest xylanase activity was observed in cultures with cellulose and with untreated sugar cane bagasse. These results indicate that pretreated sugar cane bagasse may be able to serve as a partial or total replacement for cellulose in submerged fermentation for cellulase production using P. echinulatum, which could potentially reduce future production costs of enzymatic complexes capable of hydrolyzing lignocellulosic residues to form fermented syrups.

Molecular Modeling and MM-PBSA Free Energy Analysis of Endo-1,4-β-Xylanase from Ruminococcus albus 8

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Dongling Zhan

2014-09-01

Full Text Available Endo-1,4-β-xylanase (EC 3.2.1.8 is the enzyme from Ruminococcus albus 8 (R. albus 8 (Xyn10A, and catalyzes the degradation of arabinoxylan, which is a major cell wall non-starch polysaccharide of cereals. The crystallographic structure of Xyn10A is still unknown. For this reason, we report a computer-assisted homology study conducted to build its three-dimensional structure based on the known sequence of amino acids of this enzyme. In this study, the best similarity was found with the Clostridium thermocellum (C. thermocellum N-terminal endo-1,4-β-d-xylanase 10 b. Following the 100 ns molecular dynamics (MD simulation, a reliable model was obtained for further studies. Molecular Mechanics/Poisson-Boltzmann Surface Area (MM-PBSA methods were used for the substrate xylotetraose having the reactive sugar, which was bound in the −1 subsite of Xyn10A in the 4C1 (chair and 2SO (skew boat ground state conformations. According to the simulations and free energy analysis, Xyn10A binds the substrate with the −1 sugar in the 2SO conformation 39.27 kcal·mol−1 tighter than the substrate with the sugar in the 4C1 conformation. According to the Xyn10A-2SO Xylotetraose (X4(sb interaction energies, the most important subsite for the substrate binding is subsite −1. The results of this study indicate that the substrate is bound in a skew boat conformation with Xyn10A and the −1 sugar subsite proceeds from the 4C1 conformation through 2SO to the transition state. MM-PBSA free energy analysis indicates that Asn187 and Trp344 in subsite −1 may an important residue for substrate binding. Our findings provide fundamental knowledge that may contribute to further enhancement of enzyme performance through molecular engineering.

Effect of cellulase, xylanase and α-amylase combinations on the rheological properties of Chinese steamed bread dough enriched in wheat bran.

Science.gov (United States)

Liu, Wenjun; Brennan, Margaret Anne; Serventi, Luca; Brennan, Charles Stephen

2017-11-01

The present study investigates the effects of α-amylase (6 and 10ppm), xylanase (70 and 120ppm) and cellulase (35 and 60ppm) on the rheological properties of bread dough. The mixing property of dough was measured by using a DoughLAB. The extension and stickiness of dough were analysed using the Texture Analyzer. The results illustrate that the addition of single enzyme and enzyme combinations can increase the extensibility, softening, mixing tolerance index (MTI) and stickiness, whereas decrease the resistance to extension. For water absorption, the addition of single enzyme had no significant effect, while the combination enzyme significantly (pcellulase had a synergetic effect on the dough rheology. Copyright © 2017 Elsevier Ltd. All rights reserved.

Use of Residual Biomass from the Textile Industry as Carbon Source for Production of a Low-Molecular-Weight Xylanase from Aspergillus oryzae

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Gilvan Caetano Duarte

2012-10-01

Full Text Available Pretreated dirty cotton residue (PDCR from the textile industry was used as an alternative carbon source for the submerged cultivation of Aspergillus oryzae and the production of xylanases. The filtered culture supernatant was fractionated by ultrafiltration followed by three chromatographic steps, which resulted in the isolation of a homogeneous low-molecular-weight xylanase (Xyl-O1 with a mass of 21.5 kDa as determined by sodium dodecyl sulfate-polyacrilamide gel electrophoresis (SDS-PAGE co-polymerized with 0.1% oat spelt xylan. Enzyme catalysis was the most efficient at 50 °C and pH 6.0. The Km values (mg·mL−1 for the soluble fraction of oat spelt and birchwood xylans were 10.05 and 3.34, respectively. Xyl-O1 was more stable in the presence of 5,5-dithio-bis-(2-nitrobenzoic acid (DTNB, 1,4-dithiothreitol (DTT, l-cysteine or β-mercaptoethanol, which increased the rate of catalysis by 40%, 14%, 40% or 37%, respectively. The enzyme stability was improved at pH 7.0 in the presence of 20 mM l-cysteine, with the retention of nearly 100% of the activity after 6 h at 50 °C. Xyl-O1 catalyzed the cleavage of internal β-1,4 linkages of the soluble substrates containing d-xylose residues, with a maximum efficiency of 33% for the hydrolysis of birchwood xylan after 12 h of incubation. Identification of the hydrolysis products by high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD indicated the predominance of the hydrolysis products X2-X6 during the first 12 h of incubation and the accumulation of higher xylooligomers after the elution of the last xylooligomer standard, xylohexaose.

Kinetic and Structural Characterization of a Heterohexamer 4-Oxalocrotonate Tautomerase from Chloroflexus aurantiacus J-10-fl: Implications for Functional and Structural Diversity in the Tautomerase Superfamily

International Nuclear Information System (INIS)

Burks, Elizabeth A.; Fleming, Christopher D.; Mesecar, Andrew D.; Whitman, Christian P.; Pegan, Scott D.

2010-01-01

4-Oxalocrotonate tautomerase (4-OT) isozymes play prominent roles in the bacterial utilization of aromatic hydrocarbons as sole carbon sources. These enzymes catalyze the conversion of 2-hydroxy-2,4-hexadienedioate (or 2-hydroxymuconate) to 2-oxo-3-hexenedioate, where Pro-1 functions as a general base and shuttles a proton from the 2-hydroxyl group of the substrate to the C-5 position of the product. 4-OT, a homohexamer from Pseudomonas putida mt-2, is the most extensively studied 4-OT isozyme and the founding member of the tautomerase superfamily. A search of five thermophilic bacterial genomes identified a coded amino acid sequence in each that had been annotated as a tautomerase-like protein but lacked Pro-1. However, a nearby sequence has Pro-1, but the sequence is not annotated as a tautomerase-like protein. To characterize this group of proteins, two genes from Chloroflexus aurantiacus J-10-fl were cloned, and the corresponding proteins were expressed. Kinetic, biochemical, and X-ray structural analyses show that the two expressed proteins form a functional heterohexamer 4-OT (hh4-OT), composed of three αβ dimers. Like the P. putida enzyme, hh4-OT requires the amino-terminal proline and two arginines for the conversion of 2-hydroxymuconate to the product, implicating an analogous mechanism. In contrast to 4-OT, hh4-OT does not exhibit the low-level activity of another tautomerase superfamily member, the heterohexamer trans-3-chloroacrylic acid dehalogenase (CaaD). Characterization of hh4-OT enables functional assignment of the related enzymes, highlights the diverse ways the β-α-β building block can be assembled into an active enzyme, and provides further insight into the molecular basis of the low-level CaaD activity in 4-OT.

Generation of transgenic wheat (Triticum aestivum L.) accumulating heterologous endo-xylanase or ferulic acid esterase in the endosperm

DEFF Research Database (Denmark)

Harholt, Jesper; Bach, Inga Christensen; Lind Bouquin, Solveig

2010-01-01

Endo-xylanase (from Bacillus subtilis) or ferulic acid esterase (from Aspergillus niger) were expressed in wheat under the control of the endosperm-specific 1DX5 glutenin promoter. Constructs both with and without the endoplasmic reticulum retention signal (Lys-Asp-Glu-Leu) KDEL were used....... Extensive analysis of the cell walls showed a 10%-15% increase in arabinose to xylose ratio, a 50% increase in the proportion of water-extractable arabinoxylan, and a shift in the MW of the water-extractable arabinoxylan from being mainly larger than 85 kD to being between 2 and 85 kD. Ferulic acid esterase......-expressing grains were also shrivelled, and the seed weight was decreased by 20%-50%. No ferulic acid esterase activity could be detected in wild-type grains whereas ferulic acid esterase activity was detected in transgenic lines. The grain cell walls had 15%-40% increase in water-unextractable arabinoxylan...

Improvement of bread making quality by supplementation with a recombinant xylanase produced by Pichia pastoris.

Science.gov (United States)

de Queiroz Brito Cunha, Carolina Cândida; Gama, Aline Rodrigues; Cintra, Lorena Cardoso; Bataus, Luiz Artur Mendes; Ulhoa, Cirano José

2018-01-01

Xylanases (EC 3.2.1.8) are hydrolytic enzymes, which randomly cleave the β-1,4-linked xylose residues from xylan. The synthetic gene xynBS27 from Streptomyces sp. S27 was successfully cloned and expressed in Pichia pastoris. The full-length gene consists of 729 bp and encodes 243 amino acids including 51 residues of a putative signal peptide. This enzyme was purified in two steps and was shown to have a molecular weight of 20 kDa. The purified r-XynBS27 was active against beechwood xylan and oat spelt xylan as expected for GH 11 family. The optimum pH and temperature values for the enzyme were 6.0 and 75 °C, respectively. The Km and Vmax were 12.38 mg/mL and 13.68 μmol min/mg, respectively. The r-XynBS27 showed high xylose tolerance and was inhibited by some metal ions and by SDS. r-XynBS27 was employed as an additive in the bread making process. A decrease in firmness, stiffness and consistency, and improvements in specific volume and reducing sugar content were recorded.

Thermal and chemical denaturation of Bacillus circulans xylanase: A biophysical chemistry laboratory module.

Science.gov (United States)

Raabe, Richard; Gentile, Lisa

2008-11-01

A number of institutions have been, or are in the process of, modifying their biochemistry major to include some emphasis on the quantitative physical chemistry of biomolecules. Sometimes this is done as a replacement for part for the entire physical chemistry requirement, while at other institutions this is incorporated as a component into the traditional two-semester biochemistry series. The latter is the model used for biochemistry and molecular biology majors at the University of Richmond, whose second semester of biochemistry is a course entitled Proteins: Structure, Function, and Biophysics. What is described herein is a protein thermodynamics laboratory module, using the protein Bacillus circulans xylanase, which reinforces many lecture concepts, including: (i) the denatured (D) state ensemble of a protein can be different, depending on how it was populated; (ii) intermediate states may be detected by some spectroscopic techniques but not by others; (iii) the use and assumptions of the van't Hoff approach to calculate ΔH(o) , ΔS(o) , and ΔG(o) (T) for thermal protein unfolding transitions; and (iv) the use and assumptions of an approach that allows determination of the Gibb's free energy of a protein unfolding transition based on the linear dependence of ΔG(o) on the concentration of denaturant used. This module also requires students to design their own experimental protocols and spend time in the primary literature, both important parts of an upper division lab. Copyright © 2008 International Union of Biochemistry and Molecular Biology, Inc.

Purification and characterization of endo-xylanases from Aspergillus Niger. III. An enzyme of PL 365

Energy Technology Data Exchange (ETDEWEB)

Fournier, R.A.; Frederick, M.M.; Frederick, J.R.; Reilly, P.J.

1985-04-01

An endo-xylanase (1,4-..beta..-D-xylan xylanohydrolase, EC 3.2.1.8) from Aspergillus niger was purified to homogeneity by chromatography with Ultrogel AcA 54, SP-Sephadex C-25 at pH 4.5, DEAE-Sephadex A-25 at pH 5.4, Sephadex G-50, and DEAE-Sephadex A-25 at pH 5.15. The enzyme was active on soluble xylan, on insoluble xylan only after arabinosyl-initiated branch points were removed, and on xylooligosaccharides longer than xylotetraose. There was slight activity on carboxymethyl-cellulose, arabinogalactan, glucomannan, and p-nitrophenyl-..beta..-D- glucopyranoside. The main products of the hydrolysis of soluble and insoluble xylan were oligosaccharides of intermediate length, especially the tri- and pentasaccharides. The isolectric point of the enzyme was 3.65. It had a molecular weight of 2.8 x 10/sup 4/ by SDS-gel electrophoresis, and was high in acidic amino acids but low in those containing sulfur. Highest activity in a 20-min assay at pH 5 was between 40 and 45 degrees C, with an activation energy up to 40 degrees C of 11.1 kJ/mol. The optimum pH for activity was at 5.0. The enzyme was strongly activated by Ca/sup 2 +/. 15 references.

Substituting Both the N-Terminal and "Cord" Regions of a Xylanase from Aspergillus oryzae to Improve Its Temperature Characteristics.

Science.gov (United States)

Li, Chuang; Li, Jianfang; Wang, Rui; Li, Xueqing; Li, Jinping; Deng, Chao; Wu, Minchen

2018-02-06

To improve the temperature characteristics of AoXyn11A, a mesophilic glycoside hydrolase family (GHF) 11 xylanase from Aspergillus oryzae CICC40186, its N-terminal and "cord" regions were selected to be substituted by means of the computer-aided analysis and calculation. In brief, one mutant, named ATX11A 41 , possessing the lowest root-mean-square deviation (RMSD) value was designed based on the molecular dynamics (MD) simulation by substituting the N-terminal 41 amino acids of AoXyn11A with the corresponding 42 ones of pXYL11, a thermophilic GHF11 xylanase from Thermobifida fusca. On the basis of the primary structure alignment of pXYL11 with ATX11A 41 (or AoXyn11A), another mutant, named ATX11A 41/cord , was designed by substituting the cord region ( 93 GTYNPGSGG 101 ) of ATX11A 41 with the corresponding one ( 93 GTYRPTG 99 ) of pXYL11. Both mutant-encoding genes, ATx11A 41 and ATx11A 41/cord , were constructed as designed theoretically by a megaprimer PCR technique and were expressed in Pichia pastoris GS115. The specific activities of recombinant (re) AoXyn11A, ATX11A 41 , and ATX11A 41/cord were 2916.7, 2667.6, and 2457.0 U/mg, respectively. The analysis of temperature characteristics displayed that the temperature optimum (T opt ) of reATX11A 41 or reATX11A 41/cord was 65 °C, which was 15 °C higher than that of reAoXyn11A. The thermal inactivation half-life (t 1/2 ) values of reATX11A 41 and reATX11A 41/cord at 60 °C were 55 and 83 min, respectively, whereas that of reAoXyn11A was only 18 min at 50 °C. The melting temperature (T m ) values of reAoXyn11A, reATX11A 41 , and reATX11A 41/cord were 54.2, 66.7, and 71.9 °C, respectively. In conclusion, the above findings indicated that the substitution of both the N-terminal and cord regions of a mesophilic AoXyn11A greatly contributed to its improved temperature characteristics.

A high performance Trichoderma reesei strain that reveals the importance of xylanase III in cellulosic biomass conversion.

Science.gov (United States)

Nakazawa, Hikaru; Kawai, Tetsushi; Ida, Noriko; Shida, Yosuke; Shioya, Kouki; Kobayashi, Yoshinori; Okada, Hirofumi; Tani, Shuji; Sumitani, Jun-Ichi; Kawaguchi, Takashi; Morikawa, Yasushi; Ogasawara, Wataru

2016-01-01

The ability of the Trichoderma reesei X3AB1strain enzyme preparations to convert cellulosic biomass into fermentable sugars is enhanced by the replacement of xyn3 by Aspergillus aculeatus β-glucosidase 1 gene (aabg1), as shown in our previous study. However, subsequent experiments using T. reesei extracts supplemented with the glycoside hydrolase (GH) family 10 xylanase III (XYN III) and GH Family 11 XYN II showed increased conversion of alkaline treated cellulosic biomass, which is rich in xylan, underscoring the importance of XYN III. To attain optimal saccharifying potential in T. reesei, we constructed two new strains, C1AB1 and E1AB1, in which aabg1 was expressed heterologously by means of the cbh1 or egl1 promoters, respectively, so that the endogenous XYN III synthesis remained intact. Due to the presence of wild-type xyn3 in T. reesei E1AB1, enzymes prepared from this strain were 20-30% more effective in the saccharification of alkaline-pretreated rice straw than enzyme extracts from X3AB1, and also outperformed recent commercial cellulase preparations. Our results demonstrate the importance of XYN III in the conversion of alkaline-pretreated cellulosic biomass by T. reesei. Copyright © 2015 Elsevier Inc. All rights reserved.

NCBI nr-aa BLAST: CBRC-CREM-01-1311 [SEVENS

Lifescience Database Archive (English)

Full Text Available CBRC-CREM-01-1311 ref|ZP_01426474.1| binding-protein-dependent transport systems in...ner membrane component [Herpetosiphon aurantiacus ATCC 23779] gb|EAU16750.1| binding-protein-dependent transport systems

D-Xylose fermentation, xylitol production and xylanase activities by seven new species of Sugiyamaella.

Science.gov (United States)

Sena, Letícia M F; Morais, Camila G; Lopes, Mariana R; Santos, Renata O; Uetanabaro, Ana P T; Morais, Paula B; Vital, Marcos J S; de Morais, Marcos A; Lachance, Marc-André; Rosa, Carlos A

2017-01-01

Sixteen yeast isolates identified as belonging to the genus Sugiyamaella were studied in relation to D-xylose fermentation, xylitol production, and xylanase activities. The yeasts were recovered from rotting wood and sugarcane bagasse samples in different Brazilian regions. Sequence analyses of the internal transcribed spacer (ITS) region and the D1/D2 domains of large subunit rRNA gene showed that these isolates belong to seven new species. The species are described here as Sugiyamaella ayubii f.a., sp. nov. (UFMG-CM-Y607 T  = CBS 14108 T ), Sugiyamaella bahiana f.a., sp. nov. (UFMG-CM-Y304 T  = CBS 13474 T ), Sugiyamaella bonitensis f.a., sp. nov. (UFMG-CM-Y608 T  = CBS 14270 T ), Sugiyamaella carassensis f.a., sp. nov. (UFMG-CM-Y606 T  = CBS 14107 T ), Sugiyamaella ligni f.a., sp. nov. (UFMG-CM-Y295 T  = CBS 13482 T ), Sugiyamaella valenteae f.a., sp. nov. (UFMG-CM-Y609 T  = CBS 14109 T ) and Sugiyamaella xylolytica f.a., sp. nov. (UFMG-CM-Y348 T  = CBS 13493 T ). Strains of the described species S. boreocaroliniensis, S. lignohabitans, S. novakii and S. xylanicola, isolated from rotting wood of Brazilian ecosystems, were also compared for traits relevant to xylose metabolism. S. valenteae sp. nov., S. xylolytica sp. nov., S. bahiana sp. nov., S. bonitensis sp. nov., S. boreocarolinensis, S. lignohabitans and S. xylanicola were able to ferment D-xylose to ethanol. Xylitol production was observed for all Sugiyamaella species studied, except for S. ayubii sp. nov. All species studied showed xylanolytic activity, with S. xylanicola, S. lignohabitans and S. valenteae sp. nov. having the highest values. Our results suggest these Sugiyamaella species have good potential for biotechnological applications.

Effect of exogenous xylanase, amylase, and protease as single or combined activities on nutrient digestibility and growth performance of broilers fed corn/soy diets.

Science.gov (United States)

Amerah, A M; Romero, L F; Awati, A; Ravindran, V

2017-04-01

Two trials (a 42-d performance and a 21-d cohort digestibility) were conducted to evaluate the performance and nutrient digestibility of broilers fed corn diets supplemented with exogenous xylanase, amylase, and protease as single or combined activities. A nutritionally adequate, positive control (PC) diet was formulated. The negative control (NC) diet was formulated to be lower in metabolizable energy (∼86 kcal/kg diet) and digestible amino acids (1 to 2%) compared to PC. The other 4 treatments were based on the NC and they were either supplemented with xylanase (X), amylase (A), protease (P), or a combination of X, A, and P (XAP; to provide 2,000 U of X, 200 U of A, and 4,000 U of P/kg diet). All diets were marginal in AvP and Ca and contained a background of phytase (1,000 FTU/kg). In each trial, male broiler (Ross 308) chicks were allocated to the 5 treatments (10 replicates of 20 birds/pen and 9 replicates of 8 birds/cage for the performance and digestibility trials, respectively). In the digestibility trial, ileal digesta was collected on d21 for the determination of nutrient utilization. Data were subjected to one-way ANOVA and means were separated by Tukey's HSD test. Only the XAP improved (P digestibility and apparent ileal digestible energy (AIDE). Both P and XAP improved N retention. The relative improvement in energy digestibility due to enzyme supplementation was greater at the ileal level than that measured in the excreta. The measured changes on AIDE due to supplemental enzymes were much higher than the sum of calculated contributions from starch, fat, and protein. Supplementation of all enzymes reduced (P  0.05) by dietary treatments. Both X and XAP had lower (P  0.05) FCR compared to PC. In conclusion, these results suggest a synergistic effect between X, A and P on broiler performance and nutrient digestibility. In the current study, AIDE measurements appeared to overestimate the enzyme response. Calculation of the energy contribution by

Dicty_cDB: Contig-U11717-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available Mycobacterium phage Pukovnik, com... 87 2e-15 EF101928_838( EF101928 |pid:none) ...00875_4745( CP000875 |pid:none) Herpetosiphon aurantiacus ATCC ... 87 1e-15 EU744250_49( EU744250 |pid:none)

Deletion of pH Regulator pac-3 Affects Cellulase and Xylanase Activity during Sugarcane Bagasse Degradation by Neurospora crassa.

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Amanda Cristina Campos Antoniêto

Full Text Available Microorganisms play a vital role in bioethanol production whose usage as fuel energy is increasing worldwide. The filamentous fungus Neurospora crassa synthesize and secrete the major enzymes involved in plant cell wall deconstruction. The production of cellulases and hemicellulases is known to be affected by the environmental pH; however, the regulatory mechanisms of this process are still poorly understood. In this study, we investigated the role of the pH regulator PAC-3 in N. crassa during their growth on sugarcane bagasse at different pH conditions. Our data indicate that secretion of cellulolytic enzymes is reduced in the mutant Δpac-3 at alkaline pH, whereas xylanases are positively regulated by PAC-3 in acidic (pH 5.0, neutral (pH 7.0, and alkaline (pH 10.0 medium. Gene expression profiles, evaluated by real-time qPCR, revealed that genes encoding cellulases and hemicellulases are also subject to PAC-3 control. Moreover, deletion of pac-3 affects the expression of transcription factor-encoding genes. Together, the results suggest that the regulation of holocellulase genes by PAC-3 can occur as directly as in indirect manner. Our study helps improve the understanding of holocellulolytic performance in response to PAC-3 and should thereby contribute to the better use of N. crassa in the biotechnology industry.

A family 30 glucurono-xylanase from Bacillus subtilis LC9: Expression, characterization and its application in Chinese bread making.

Science.gov (United States)

Guo, Yalan; Gao, Zhen; Xu, Jiaxing; Chang, Siyuan; Wu, Bin; He, Bingfang

2018-05-22

A GH30-8 endoxylanase was identified from an environmental Bacillus subtilis isolate following growth selection on aspen wood glucuronoxylan. The putative endoxylanase was cloned for protein expression and characterization in the Gram-positive protease deficient protein expression host B. subtilis WB800. The extracellular activity obtained was 55 U/mL, which was 14.5-fold higher than that obtained with the native species. The apparent molecular mass of BsXyn30 was estimated as 43 kDa by SDS-PAGE. BsXyn30 showed an optimal activity at pH 7.0 and 60 °C. Recombinant BsXyn30 displayed maximum activity against aspen wood xylan, followed by beechwood xylan but showed no catalytic activity on arabinose-substituted xylans. Analysis of hydrolyzed products of beechwood xylan by thin-layer chromatography and mass spectroscopy revealed the presence of xylooligosaccharides with a single methyl-glucuronic acid residue. BsXyn30 exhibited very low activity for hydrolysis xylotetraose and xylopentaose, but had no detectable activity against xylobiose and xylotriose. Using BsXyn30 as an additive in breadmaking, a decrease in water-holding capacity, an increase in dough expansion as well as improvements in volume and specific volume of the bread were recorded. Thus, the present study provided the basis for the application of GH30 xylanase in breadmaking. Copyright © 2018 Elsevier B.V. All rights reserved.

ISOLASI, SKRINING DAN IDENTIFIKASI JAMUR XILANOLITIK LOKAL YANG BERPOTENSI SEBAGAI AGENSIA PEMUTIH PULP YANG RAMAH LINGKUNGAN (Isolation, Screening and Identification Xylanolytic Local Fungi that Potentially as Pulp Bleaching Agents

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Elisa Nurnawati

2015-01-01

Xylanase has great potential for industry application. Application of xylanase can be done in pretreatment of pulp bleaching in the pulp and paper industry. Enzyme application can reduce the use of chlorine compounds that are harmful to the environment. Therefore, xylanase that used in pulp bleaching should be free of cellulase activity. Fungi are one of the groups of microbes that are able to produce xylanase. The aims of this study was to obtain local xylanase-producing fungal isolates from soil that assumed contain of xylan. The source of fungal isolates were the soil around the pulp and paper industry; Acacia forests in the district Ogan Ilir and Muara Enim, South Sumatra; Wanagama, Yogyakarta; sawmills in Palembang and Yogyakarta; and Palembang landfill. Based on the initial screening in the agar basal medium, 111 fungal isolates were obtained. Most of them were the xylanase-producing fungi, but only 12 fungal isolates that have high xylanolytic capabilities. Further screening was performed on xylan liquid basal medium. The results showed that the fungus identified as Chaetomium globosum, Penicillium simplicissimum, Aspergillus tamarii and Monocillium have higher xylanase specific activity than the other isolates. They were also have lignolytic and cellulolytic activities. Therefore, fungal xylanase potentially developed as a pulp bleaching agent.

Notes on Malesian Fabaceae (Leguminosae–Papilionoideae). 10. The genus Alysicarpus

NARCIS (Netherlands)

Adema, F.

2003-01-01

Alysicarpus Desv. is revised for the Flora Malesiana area. The recently described species A. aurantiacus Pedley is recorded for several localities in Papua New Guinea. Alysicarpus monilifer L. is recorded for Luzon (Philippines). The variability of A. vaginalis is discussed. A key for the Malesian

Valorization of Brewer's spent grain to prebiotic oligosaccharide: Production, xylanase catalyzed hydrolysis, in-vitro evaluation with probiotic strains and in a batch human fecal fermentation model.

Science.gov (United States)

Sajib, Mursalin; Falck, Peter; Sardari, Roya R R; Mathew, Sindhu; Grey, Carl; Karlsson, Eva Nordberg; Adlercreutz, Patrick

2018-02-20

Brewer's spent grain (BSG) accounts for around 85% of the solid by-products from beer production. BSG was first extracted to obtain water-soluble arabinoxylan (AX). Using subsequent alkali extraction (0.5 M KOH) it was possible to dissolve additional AX. In total, about 57% of the AX in BSG was extracted with the purity of 45-55%. After comparison of nine xylanases, Pentopan mono BG, a GH11 enzyme, was selected for hydrolysis of the extracts to oligosaccharides with minimal formation of monosaccharides. Growth of Bifidobacterium adolescentis (ATCC 15703) was promoted by the enzymatic hydrolysis to arabinoxylooligosaccharides, while Lactobacillus brevis (DSMZ 1264) utilized only unsubstituted xylooligosaccharides. Furthermore, utilization of the hydrolysates by human gut microbiota was also assessed in a batch human fecal fermentation model. Results revealed that the rates of fermentation of the BSG hydrolysates by human gut microbiota were similar to that of commercial prebiotic fructooligosaccharides, while inulin was fermented at a slower rate. In summary, a sustainable process to valorize BSG to functional food ingredients has been proposed. Copyright © 2018 Elsevier B.V. All rights reserved.

A xylanase with broad pH and temperature adaptability from Streptomyces megasporus DSM 41476, and its potential application in brewing industry.

Science.gov (United States)

Qiu, Zhenhua; Shi, Pengjun; Luo, Huiying; Bai, Yingguo; Yuan, Tiezheng; Yang, Peilong; Liu, Suchun; Yao, Bin

2010-05-05

A xylanase gene, xynAM6, was isolated from the genomic DNA library of Streptomyces megasporus DSM 41476 using colony PCR screening method. The 1440-bp full-length gene encodes a 479-amino acid peptide consisting of a putative signal peptide of 36 residues, a family 10 glycoside hydrolase domain and a family 2 carbohydrate-binding module. The mature peptide of xynAM6 was successfully expressed in Pichia pastoris GS115. The optimal pH and temperature were pH 5.5 and 70°C, respectively. The enzyme showed broad temperature adaptability (>60% of the maximum activity at 50-80°C), had good thermostability at 60°C and 70°C, remained stable at pH 4.0-11.0, and was resistant to most proteases. The Km and Vmax values for oat spelt xylan were 1.68mgml(-1) and 436.76μmolmin(-1)mg(-1), respectively, and 2.33mgml(-1) and 406.93μmolmin(-1)mg(-1) for birchwood xylan, respectively. The hydrolysis products of XYNAM6 were mainly xylose and xylobiose. Addition of XYNAM6 (80U) to the brewery mash significantly reduced the filtration rate and viscosity by 36.33% and 35.51%, respectively. These favorable properties probably make XYNAM6 a good candidate for application in brewing industry. Copyright © 2010 Elsevier Inc. All rights reserved.

Improving the temperature characteristics and catalytic efficiency of a mesophilic xylanase from Aspergillus oryzae, AoXyn11A, by iterative mutagenesis based on in silico design.

Science.gov (United States)

Li, Xue-Qing; Wu, Qin; Hu, Die; Wang, Rui; Liu, Yan; Wu, Min-Chen; Li, Jian-Fang

2017-12-01

To improve the temperature characteristics and catalytic efficiency of a glycoside hydrolase family (GHF) 11 xylanase from Aspergillus oryzae (AoXyn11A), its variants were predicted based on in silico design. Firstly, Gly 21 with the maximum B-factor value, which was confirmed by molecular dynamics (MD) simulation on the three-dimensional structure of AoXyn11A, was subjected to site-saturation mutagenesis. Thus, one variant with the highest thermostability, AoXyn11A G21I , was selected from the mutagenesis library, E. coli/Aoxyn11A G21X (X: any one of 20 amino acids). Secondly, based on the primary structure multiple alignment of AoXyn11A with seven thermophilic GHF11 xylanases, AoXyn11A Y13F or AoXyn11A G21I-Y13F , was designed by replacing Tyr 13 in AoXyn11A or AoXyn11A G21I with Phe. Finally, three variant-encoding genes, Aoxyn11A G21I , Aoxyn11A Y13F and Aoxyn11A G21I-Y13F , were constructed by two-stage whole-plasmid PCR method, and expressed in Pichia pastoris GS115, respectively. The temperature optimum (T opt ) of recombinant (re) AoXyn11A G21I-Y13F was 60 °C, being 5 °C higher than that of reAoXyn11A G21I or reAoXyn11A Y13F , and 10 °C higher than that of reAoXyn11A. The thermal inactivation half-life (t 1/2 ) of reAoXyn11A G21I-Y13F at 50 °C was 240 min, being 40-, 3.4- and 2.5-fold longer than those of reAoXyn11A, reAoXyn11A G21I and reAoXyn11A Y13F . The melting temperature (T m ) values of reAoXyn11A, reAoXyn11A G21I , reAoXyn11A Y13F and reAoXyn11A G21I-Y13F were 52.3, 56.5, 58.6 and 61.3 °C, respectively. These findings indicated that the iterative mutagenesis of both Gly21Ile and Tyr13Phe improved the temperature characteristics of AoXyn11A in a synergistic mode. Besides those, the catalytic efficiency (k cat /K m ) of reAoXyn11A G21I-Y13F was 473.1 mL mg -1 s -1 , which was 1.65-fold higher than that of reAoXyn11A.

Isolation, screening, and identification of potential cellulolytic and xylanolytic producers for biodegradation of untreated oil palm trunk and its application in saccharification of lemongrass leaves.

Science.gov (United States)

Ang, S K; Yahya, Adibah; Abd Aziz, Suraini; Md Salleh, Madihah

2015-01-01

This study presents the isolation and screening of fungi with excellent ability to degrade untreated oil palm trunk (OPT) in a solid-state fermentation system (SSF). Qualitative assay of cellulases and xylanase indicates notable secretion of both enzymes by 12 fungal strains from a laboratory collection and 5 strains isolated from a contaminated wooden board. High production of these enzymes was subsequently quantified in OPT in SSF. Aspergillus fumigates SK1 isolated from cow dung gives the highest xylanolytic activity (648.448 U g(-1)), generally high cellulolytic activities (CMCase: 48.006, FPase: 6.860, beta-glucosidase: 16.328 U g(-1)) and moderate lignin peroxidase activity (4.820 U/g), and highest xylanolytic activity. The xylanase encoding gene of Aspergillus fumigates SK1 was screened using polymerase chain reaction by a pair of degenerate primers. Through multiple alignment of the SK1 strain's xylanase nucleotide sequences with other published xylanases, it was confirmed that the gene belonged to the xylanase glycoside hydrolase family 11 (GH11) with a protein size of 24.49 kD. Saccharification of lemongrass leaves using crude cellulases and xylanase gives the maximum reducing sugars production of 6.84 g/L with glucose as the major end product and traces of phenylpropanic compounds (vanillic acid, p-coumaric acid, and ferulic acid).

Fermentation characteristics in hay from Cynodon and crop stubble treated with exogenous enzymes

Directory of Open Access Journals (Sweden)

Yânez André Gomes Santana

Full Text Available ABSTRACT The effect of treatment with xylanase and β-glucanase was evaluated for gas production and the ruminal degradation of nutrients from the hay of Tifton 85 grass and the stubble of maize, sorghum, peanut, sunflower and sesame crops. Two commercial fibrolytic enzymes were used (Dyadic xylanase PLUS - Xylanase; BrewZyme LP-β-glucanase, added to the hay at doses of 7.5 units of endoglucanase and 0.46 units of xylanase per 500 mg/gDM, for the cellulase and xylanase products respectively. The chemical composition of the hay was determined for no enzyme application and 24 hours after enzyme treatment, and the in vitro gas production and in situ microbial degradation was estimated for dry matter, organic matter, neutral detergent fibre and truly-degradable organic matter after 24 hours of incubation in the rumen. Enzyme treatment of the hay from Tifton 85 grass and the stubble of maize, sorghum, sunflower, peanut and sesame crops with the exogenous fibrolytic enzymes β-glucanase and xylanase influences in vitro gas production, and the in situ degradation of dry matter, organic matter, neutral detergent fibre and truly-degradable organic matter in the rumen. This variation can be attributed to differences in the chemical composition of the hay from the grass and the crop stubble, and to the different ways the enzymes act upon the cell wall.

Screening and characterizing of xylanolytic and xylose-fermenting yeasts isolated from the wood-feeding termite, Reticulitermes chinensis.

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Sameh Samir Ali

Full Text Available The effective fermentation of xylose remains an intractable challenge in bioethanol industry. The relevant xylanase enzyme is also in a high demand from industry for several biotechnological applications that inevitably in recent times led to many efforts for screening some novel microorganisms for better xylanase production and fermentation performance. Recently, it seems that wood-feeding termites can truly be considered as highly efficient natural bioreactors. The highly specialized gut systems of such insects are not yet fully realized, particularly, in xylose fermentation and xylanase production to advance industrial bioethanol technology as well as industrial applications of xylanases. A total of 92 strains from 18 yeast species were successfully isolated and identified from the gut of wood-feeding termite, Reticulitermes chinensis. Of these yeasts and strains, seven were identified for new species: Candida gotoi, Candida pseudorhagii, Hamamotoa lignophila, Meyerozyma guilliermondii, Sugiyamaella sp.1, Sugiyamaella sp. 2, and Sugiyamaella sp.3. Based on the phylogenetic and phenotypic characterization, the type strain of C. pseudorhagii sp. nov., which was originally designated strain SSA-1542T, was the most frequently occurred yeast from termite gut samples, showed the highly xylanolytic activity as well as D-xylose fermentation. The highest xylanase activity was recorded as 1.73 and 0.98 U/mL with xylan or D-xylose substrate, respectively, from SSA-1542T. Among xylanase-producing yeasts, four novel species were identified as D-xylose-fermenting yeasts, where the yeast, C. pseudorhagii SSA-1542T, showed the highest ethanol yield (0.31 g/g, ethanol productivity (0.31 g/L·h, and its fermentation efficiency (60.7% in 48 h. Clearly, the symbiotic yeasts isolated from termite guts have demonstrated a competitive capability to produce xylanase and ferment xylose, suggesting that the wood-feeding termite gut is a promising reservoir for novel

Feruloyl esterase from Aspergillus clavatus improves xylan hydrolysis of sugarcane bagasse

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Dyoni M. de Oliveira

2016-12-01

Full Text Available Feruloyl esterase is a subclass of carboxylic acid esterases with the capacity to release ferulic acid and other cinnamic acids from plant cell walls and synthetic substrates. Feruloyl esterases act synergistically with xylanases removing ferulic acid residues esterified to arabinoxylans. Feruloyl esterase type D from Aspergillus clavatus (AcFAE was expressed in Escherichia coli, purified, and applied with a commercial xylanase consortium (Novozymes for hydrolysis of sugarcane bagasse. Feruloyl esterase plus xylanase increased 5.13-fold the releasing of ferulic acid from sugarcane bagasse. Removal of only 7.7% of ferulic acid content by AcFAE increased 97.3% the sugarcane bagasse hydrolysis by xylanase. These data support the use of AcFAE as an interesting adjuvant enzyme to improve lignocellulose digestion and biotechnological tool for biorefineries.

The process-related dynamics of microbial community during a simulated fermentation of Chinese strong-flavored liquor.

Science.gov (United States)

Zhang, Yanyan; Zhu, Xiaoyu; Li, Xiangzhen; Tao, Yong; Jia, Jia; He, Xiaohong

2017-09-15

Famous Chinese strong-flavored liquor (CSFL) is brewed by microbial consortia in a special fermentation pit (FT). However, the fermentation process was not fully understood owing to the complicate community structure and metabolism. In this study, the process-related dynamics of microbial communities and main flavor compounds during the 70-day fermentation process were investigated in a simulated fermentation system. A three-phase model was proposed to characterize the process of the CSFL fermentation. (i) In the early fermentation period (1-23 days), glucose was produced from macromolecular carbohydrates (e.g., starch). The prokaryotic diversity decreased significantly. The Lactobacillaceae gradually predominated in the prokaryotic community. In contrast, the eukaryotic diversity rose remarkably in this stage. Thermoascus, Aspergillus, Rhizopus and unidentified Saccharomycetales were dominant eukaryotic members. (ii) In the middle fermentation period (23-48 days), glucose concentration decreased while lactate acid and ethanol increased significantly. Prokaryotic community was almost dominated by the Lactobacillus, while eukaryotic community was mainly comprised of Thermoascus, Emericella and Aspergillus. (iii) In the later fermentation period (48-70 days), the concentrations of ethyl esters, especially ethyl caproate, increased remarkably. The CSFL fermentation could undergo three stages: saccharification, glycolysis and esterification. Saccharomycetales, Monascus, and Rhizopus were positively correlated to glucose concentration (P fermentation, were observed firstly. This study observed comprehensive dynamics of microbial communities during the CSFL fermentation, and it further revealed the correlations between some crucial microorganisms and flavoring chemicals (FCs). The results from this study help to design effective strategies to manipulate microbial consortia for fermentation process optimization in the CSFL brew practice.

What makes organic livestock production sustainable?

DEFF Research Database (Denmark)

Oudshoorn, Frank W; Stubsgaard, A; Grøn Sørensen, Claus

2014-01-01

The effect of a current commercial xylanase (DAN) and experimental xylanase (EX), and EX in combination with protease (EXP), on the degradation and apparent ileal digestibility (AID) of non-starch polysaccharides (NSP) in wheat Distillers Dried Grains with Solubles (DDGS), was studied in 8 ileum-...

Next-generation non-starch polysaccharide-degrading, multi-carbohydrase complex rich in xylanase and arabinofuranosidase to enhance broiler feed digestibility.

Science.gov (United States)

Cozannet, Pierre; Kidd, Michael T; Montanhini Neto, Roberto; Geraert, Pierre-André

2017-08-01

This study was carried out to evaluate the effect of a multi-carbohydrase complex (MCC) rich in xylanase (Xyl) and arabinofuranosidase (Abf) on overall broiler feed digestibility in broilers. Energy utilization and digestibility of dry matter (DM), organic matter (OM), protein, starch, fat, and insoluble and soluble fibers were measured using the mass-balance method. The experiment was carried out on 120 broilers (3-week-old chickens). Broilers were distributed over 8 treatments to evaluate the effect of the dietary arabinoxylan content and nutrient density with and without MCC (Rovabio® Advance). The graded content of arabinoxylan (AX) was obtained using different raw materials (wheat, rye, barley, and dried distillers' wheat). Diet-energy density was modified with added fat. Measurements indicated that nutrient density and AX content had a significant effect on most digestibility parameters. Apparent metabolizable energy (AME) was significantly increased (265 kcal kg-1) by MCC. The addition of MCC also resulted in significant improvement in the digestibility of all evaluated nutrients, with average improvements of 3.0, 3.3, 3.2, 3.0, 6.2, 2.9, 5.8, and 3.8% units for DM, OM, protein, starch, fat, insoluble and soluble fibers, and energy utilization, respectively. The interaction between MCC and diet composition was significant for the digestibility of OM, fat, protein, and energy. Nutrient digestibility and diet AME were negatively correlated with AX content (P digestible nutrient (i.e., starch, protein, fat, insoluble and soluble fibers) content with and without MCC (R2 = 0.87; RSD = 78 kcal kg-1). This study confirms that the presence of AX in wheat-based diets and wheat-based diets with other cereals and cereal by-products reduces nutrient digestibility in broiler chickens. Furthermore, the dietary addition of MCC, which is rich in Xyn and Abf, reduced deleterious effect of fiber and improved overall nutrient digestibility in broiler diets. © 2017 Poultry

Impact of orientation of carbohydrate binding modules family 22 and 6 on the catalytic activity of Thermotoga maritima xylanase XynB.

Science.gov (United States)

Tajwar, Razia; Shahid, Saher; Zafar, Rehan; Akhtar, Muhammad Waheed

2017-11-01

Xylanase XynB of the hyperthermophile Thermotoga maritima, which belongs to glycoside hydrolase family 10 (GH10), does not have an associated carbohydrate binding module (CBM) in the native state. CBM6 and CBM22 from a thermophile Clostridium thermocellum were fused to the catalytic domain of XynB (XynB-C) to determine the effects on activity and other properties. XynB-B22C and XynB-CB22, produced by fusing CBM22 to the N- and C-terminal of XynB-C, showed 1.7- and 3.24-fold increase in activity against the insoluble birchwood xylan, respectively. Similarly, CBM6 when attached to the C-terminal of XynB-C resulted in 2.0-fold increase in activity, whereas its attachment to the N-terminal did not show any increase of activity. XynB-B22C and XynB-CB22 retained all the activity, whereas XynB-B6C and XynB-CB6 lost 17 and 11% of activity, respectively, at 60°C for 4h. Thermostability data and the secondary structure contents obtained by molecular modelling are in agreement with the data from circular dichroism analysis. Molecular modelling analysis showed that the active site residues of the catalytic domain and the binding residues of CBM6 and CBM22 were located on the surface of molecule, except XynB-B6C, where the binding residues were found somewhat buried. In the case of XynB-CB22, the catalytic and the binding residues seem to be located favorably adjacent to each other, thus showing higher increase in activity. This study shows that the active site residues of the catalytic domain and the binding residues of the CBM are arranged in a unique fashion, not reported before. Copyright © 2017 Elsevier Inc. All rights reserved.

Purification, crystallization and preliminary X-ray analysis of a thermostable glycoside hydrolase family 43 beta-xylosidase from Geobacillus thermoleovorans IT-08

NARCIS (Netherlands)

Rohman, Ali; van Oosterwijk, Niels; Kralj, Slavko; Dijkhuizen, Lubbert; Dijkstra, Bauke W.; Puspaningsih, Ni Nyoman Tri

2007-01-01

The main enzymes involved in xylan-backbone hydrolysis are endo-1,4-beta-xylanase and beta-xylosidase. beta-Xylosidase converts the xylo-oligosaccharides produced by endo-1,4-beta-xylanase into xylose monomers. The beta-xylosidase from the thermophilic Geobacillus thermoleovorans IT-08, a member of

Efeitos do centeio, do trigo e da suplementação com xilanases sobre o valor nutricional de dietas e o desempenho de frangos corte Effects of rye, wheat and xylanase supplementation on diet nutritive value and broiler chicken performance

Directory of Open Access Journals (Sweden)

José Luís Teixeira de Abreu Medeiros Mourão

2009-12-01

Full Text Available Três experimentos foram realizados para avaliar os efeitos de dietas formuladas com 53% de trigo ou centeio, suplementadas ou não com a enzima xilanase (0,06%, sobre a digestibilidade de nutrientes e a energia metabolizável das dietas e sobre o desempenho e desenvolvimento do trato digestivo de frangos de corte. Como testemunha foi usada uma dieta com 53% de milho. No primeiro experimento, as digestibilidades da matéria seca, matéria orgânica e gordura e energia metabolizável corrigida para o nitrogênio (EMAn das dietas com centeio foram menores que daquelas com trigo (2.556 kcal/kg vs 2.842 kcal/kg e menores no conjunto dessas dietas que na dieta com milho (2.684 kcal/kg vs 3.010 kcal/kg. A digestibilidade da matéria orgânica e a EMAn das dietas com centeio também foi inferior às da dieta com trigo. A suplementação com xilanases não afetou a utilização digestiva das dietas com centeio ou com trigo. No segundo experimento, nos frangos alimentados com as dietas com centeio, o menor ganho de peso e consumo de EMAn e a pior conversão alimentar ocorreram entre os 8 e os 35 dias de idade. A conversão alimentar foi de 2,17 para as dietas com centeio e 1,88 para a dieta com milho. A adição de xilanases às dietas com centeio ou trigo não melhorou a conversão alimentar. Nos frangos alimentados com as dietas com centeio durante 31 dias, o duodeno-jejuno e íleo foram maiores e o rendimento de carcaça menor que nos frangos alimentados com a dieta testemunha (71,6% vs 74,4%. As dietas com trigo não afetaram essas características. Os pesos do pâncreas e do fígado também não foram alterados pelas dietas.Three trials with were conducted to evaluate the effects of diets with 53% rye (diet C or 53% wheat (diet T supplemented or not with xylanase enzymes (0.06% on nutrient digestibility and metabolizable energy and the performance and development of the broiler chicken digestive tract. A diet with 53% corn was used as control. In

Dicty_cDB: Contig-U07017-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available hia coli IAI1 chromosome... 107 2e-22 ( P30176 ) RecName: Full=Swarming motility ...7 2e-22 (Q323Z6) RecName: Full=Swarming motility protein ybiA; &CP00003... 105 6e-22 CP000875_353( CP000875 ...|pid:none) Herpetosiphon aurantiacus ATCC 2... 105 6e-22 (Q0T6G3) RecName: Full=Swarming motility protein yb

Effects of cell wall degrading enzymes on carbohydrate fractions and metabolites in stomach and ileum of pigs fed wheat bran based diets

NARCIS (Netherlands)

Meulen, van der J.; Inborr, J.; Bakker, J.G.M.

2001-01-01

Pigs were fed diets containing 40 heat bran incubated with a water:acetic acid mixture (control, C) and a cellulase (Cel-i) or xylanase (Xyl-i) preparation or with addition of the cellulase (Cel-a) or xylanase (Xyl-a) preparation immediately before feeding. Stomach and ileal samples were analysed

Effects of wheat cultivar, metabolizable energy level, and xylanase supplementation to laying hens diet on performance, egg quality traits, and selected blood parameters

Directory of Open Access Journals (Sweden)

Masoud Mirzaee

2014-10-01

Full Text Available A 2 x 2 x 2 factorial arrangement of treatments was conducted to evaluate the effects of two dietary apparent metabolizable energy (AME levels (2,720 and 2,580 kcal kg-1 diet and enzyme (0 and 0.3 g kg-1 diet, Grindazym® GP 15,000 with mostly xylanase activity supplementation on the performance of laying hens fed diets based on two wheat cultivars (Marvdasht and Sardari. Experimental diets were formulated to have a constant energy to protein ratio and were fed to 65-wk-old Lohmann LSL-Lite laying hens for 7 wk. The lower level of AME reduced egg production and egg mass (p<0.05 and increased feed conversion ratio (p<0.05. Enzyme addition increased feed intake of the birds fed a diet with Sardari cultivar (p<0.05 but had no effect on feed intake of the birds fed a diet with Marvdasht cultivar (p>0.05. Nevertheless, birds receiving diets based on Marvdasht cultivar had higher feed intake and egg mass than that of those receiving diets based on Sardari cultivar (p<0.05. The birds fed diets based on Marvdasht cultivar produced less undesired eggs and had better yolk color as compared with the birds fed diets based on Sardari cultivar (p<0.05. The serum concentration of glucose increased by enzyme supplementation when birds receiving lower AME level (p<0.05. These results indicate that enzyme supplementation may have a positive effect on the feed intake of laying hens when fed on wheat-based diets; however, this effect is cultivar dependent and does not necessarily mean that enzyme supplementation always benefit production.

Strain Improvement of Fungi by Induced Mutation through Gamma Irradiation and Selection for Animal Feed Enzymes Production and its Fermentation Process

International Nuclear Information System (INIS)

Konsue, Parichart; Piadang, Nattayana; Kitpreechavanich, Vichien

2006-09-01

Ten from eighty-nine strains of thermophilic fungi Thermomyces lanuginosus produced high level insoluble xylan degrading enzyme when cultured in submerge condition using untreated corncob as a substrate. Strain of T. lanuginosus THKU56 produced high level of insoluble xylan degrading enzyme with the most stable which was remained 28.2 and 58.9 % after treated at pH 3.5 and 70 o C for 1 h, respectively. To improve xylanase production, the strain was subjected to mutate using gamma ray at 0.4 - 1.6 kGy. The result showed the mutant strains produced insoluble xylanase activity lesser than wild type. Thus wild type strain THKU56 was then selected as potent strains for enzyme production and medium optimization was investigated using a central composite design. The four components, corncobs, yeast extract, KH 2 PO 4 and Tween 8 0, were parameters of this study. It was found that corncobs and yeast extract were discovered to affect on the xylanase production. The optimal concentration of the active nutrients for xylanase production were 41 g/l of corncobs and 24 g/l of yeast extract, which gave a predicted yield of 526.7 units/ml after 5 days culture at a temperature of 50 o C. The xylanase activity obtained from the experiment was 541 units/ml that was close to the predicted value

Genomic distribution of B-vitamin auxotrophy and uptake transporters in environmental bacteria from the Chloroflexi phylum

Energy Technology Data Exchange (ETDEWEB)

Rodionova, Irina A.; Li, Xiaoqing; Plymale, Andrew E.; Motamedchaboki, Khatereh; Konopka, Allan; Romine, Margaret F.; Fredrickson, Jim K.; Osterman, Andrei; Rodionov, Dmitry A.

2015-04-01

Bacteria from the Chloroflexi phylum are dominant members of phototrophic microbial mat communities in terrestrial thermal environments. Vitamins of B-group are key intermediates (precursors) in the biosynthesis of indispensable enzyme cofactors driving numerous metabolic processes in all forms of life. A genomics-based reconstruction and comparative analysis of respective biosynthetic and salvage pathways and riboswitch regulons in over 20 representative Chloroflexi genomes revealed a widespread auxotrophy for some of the vitamins. The most prominent predicted phenotypic signature, auxotrophy for vitamins B1 and B7 was experimentally confirmed for the best studied model organism Chloroflexus aurantiacus. These observations along with identified candidate genes for the respective uptake transporters pointed to B vitamin exchange as an important aspect of syntrophic metabolism in microbial communities. Inferred specificities of homologous substrate-binding components of ABC transporters for vitamins B1 (ThiY) and B2 (RibY) were verified by thermofluorescent shift approach. A functional activity of the thiamine-specific transporter ThiXYZ from C. aurantiacus was experimentally verified by genetic complementation in E. coli. Expanding the integrative approach, which was applied here for a comprehensive analysis of B-vitamin metabolism in Chloroflexi would allow reconstruction of metabolic interdependencies in microbial communities.

Monosaccharides and Ethanol Production from Superfine Ground Sugarcane Bagasse Using Enzyme Cocktail

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Jingbo Li

2014-03-01

Full Text Available In this work, the effect of particle size on the enzymatic hydrolysis of milled and sieved sugarcane bagasse (SCB was studied. The enzymatic hydrolysis and fermentability of superfine ground SCB (SGP400 using an enzyme cocktail strategy were also explored. Particle size reduction improved the enzymatic hydrolysis. The highest glucose yield was 44.75%, which was obtained from SGP400. The enzyme cocktail strategy greatly enhanced the glucose and xylose yield. The maximum glucose and xylose yield was from the enzyme cocktail of cellulase, xylanase, and pectinase. Synergistic action between xylanase and pectinase as well as cellulase and pectinase was quite noticeable. Hydrolysis times affected the degree of synergism. Ethanol production was carried out by employing simultaneous saccharification and fermentation (SSF and semi-SSF using enzymes and their cocktails. Semi-SSF was found to be the better one compared with SSF. Xylanase and pectinase aided the ethanol production in both fermentation modes. Ethanol yield was 7.81 and 7.30 g/L for semi-SSF and SSF, respectively by using an enzyme cocktail of cellulase, β-glucosidase, pectinase, and xylanase.

Biochemical characterization of thermophilic lignocellulose degrading enzymes and their potential for biomass bioprocessing

Energy Technology Data Exchange (ETDEWEB)

Zambare, Vasudeo; Zambare, Archana; Christopher, Lew P. [Center for Bioprocessing Research & Development, South Dakota School of Mines and Technology, Rapid City 57701, SD (United States); Muthukumarappan, Kasiviswanath [Center for Bioprocessing Research & Development, South Dakota State University, Brookings 57007, SD (United States)

2011-07-01

A thermophilic microbial consortium (TMC) producing hydrolytic (cellulolytic and xylanolytic) enzymes was isolated from yard waste compost following enrichment with carboxymethyl cellulose and birchwood xylan. When grown on 5% lignocellulosic substrates (corn stover and prairie cord grass) at 60C, the thermophilic consortium produced more xylanase (up to 489 U/l on corn stover) than cellulase activity (up to 367 U/l on prairie cord grass). Except for the carboxymethyl cellulose-enriched consortium, thermo-mechanical extrusion pretreatment of these substrates had a positive effect on both activities with up to 13% and 21% increase in the xylanase and cellulase production, respectively. The optimum temperatures of the crude cellulase and xylanase were 60C and 70C with half-lives of 15 h and 18 h, respectively, suggesting higher thermostability for the TMC xylanase. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the crude enzyme exhibited protein bands of 25-77 kDa with multiple enzyme activities containing 3 cellulases and 3 xylanases. The substrate specificity declined in the following descending order: avicel>birchwood xylan>microcrystalline cellulose>filter paper>pine wood saw dust>carboxymethyl cellulose. The crude enzyme was 77% more active on insoluble than soluble cellulose. The Km and Vmax values were 36.49 mg/ml and 2.98 U/mg protein on avicel (cellulase), and 22.25 mg/ml and 2.09 U/mg protein, on birchwood xylan (xylanase). A total of 50 TMC isolates were screened for cellulase and xylanase secretion on agar plates. All single isolates showed significantly lower enzyme activities when compared to the thermophilic consortia. This is indicative of the strong synergistic interactions that exist within the thermophilic microbial consortium and enhance its hydrolytic capabilities. It was further demonstrated that the thermostable enzyme-generated lignocellulosic hydrolyzates can be fermented to bioethanol by a recombinant strain of Escherichia coli

Unique double concentric ring organization of light harvesting complexes in Gemmatimonas phototrophica

Czech Academy of Sciences Publication Activity Database

Dachev, Marko; Bína, David; Sobotka, Roman; Moravcová, Lenka; Gardian, Zdenko; Kaftan, David; Šlouf, V.; Fuciman, M.; Polívka, Tomáš; Koblížek, Michal

2017-01-01

Roč. 15, č. 12 (2017), č. článku e2003943. E-ISSN 1545-7885 R&D Projects: GA ČR GA15-00703S; GA ČR GBP501/12/G055; GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 ; RVO:60077344 Keywords : BACTERIUM CHLOROFLEXUS-AURANTIACUS * EXCITATION-ENERGY TRANSFER * PURPLE BACTERIA Subject RIV: EE - Microbiology, Virology; BO - Biophysics (BC-A) OBOR OECD: Microbiology; Biophysics (BC-A) Impact factor: 9.797, year: 2016

Effects of enzymes to improve sensory quality of frozen dough bread and analysis on its mechanism.

Science.gov (United States)

Wang, Xuan; Pei, Dudu; Teng, Yuefei; Liang, Jianfen

2018-01-01

Baking quality of frozen dough is negatively affected by dough weakening and by a reduction in both yeast viability and activity during freezing and frozen storage. The objective of this study was to investigate effects of different enzymes, such as α-amylase, xylanase, celluase, glucose oxidase, and lipase on the texture and sensory quality of bread after frozen storage, as well as on dough properties, in terms of fermentation characteristics, freezable water contents and microstructure. Except for α-amylase, other enzymes improved the bread sensory quality and got higher overall acceptability, especially xylanase. Dough fermentative behavior showed that the maximum heights of frozen dough were increased by 33.2, 19.7 and 7.4%, respectively with xylanase, cellulase and lipase. Cellulase lowered gas holding ability of dough. Thermodynamic properties indicated that addition of enzyme decreased the freezable water contents in frozen dough. Scanning electronic microscopy revealed that freezing and frozen storage disrupted dough gluten network causing separation of starch granules from the gluten matrix. Inclusion of cellulase, xylanase and lipase made the frozen dough having a more continuous gluten network and smoother surface, and glucose oxidase increased the stability of the gluten work.

Bioprocessing of wheat bran for the production of lignocellulolytic enzyme cocktail by Cotylidia pannosa under submerged conditions

Science.gov (United States)

Sharma, Deepika; Garlapat, Vijay Kumar; Goel, Gunjan

2016-01-01

ABSTRACT Characterization and production of efficient lignocellulytic enzyme cocktails for biomass conversion is the need for biofuel industry. The present investigation reports the modeling and optimization studies of lignocellulolytic enzyme cocktail production by Cotylidia pannosa under submerged conditions. The predominant enzyme activities of cellulase, xylanase and laccase were produced in the cocktail through submerged conditions using wheat bran as a substrate. A central composite design approach was utilized to model the production process using temperature, pH, incubation time and agitation as input variables with the goal of optimizing the output variables namely cellulase, xylanase and laccase activities. The effect of individual, square and interaction terms on cellulase, xylanase and laccase activities were depicted through the non-linear regression equations with significant R2 and P-values. An optimized value of 20 U/ml, 17 U/ml and 13 U/ml of cellulase, xylanase and laccase activities, respectively, were obtained with a media pH of 5.0 in 77 h at 31C, 140 rpm using wheatbran as a substrate. Overall, the present study introduces a fungal strain, capable of producing lignocellulolytic enzyme cocktail for subsequent applications in biofuel industry. PMID:26941214

Prospect for Developing a Consolidated Bioprocessing (CBP) Strain Using Xylan as the Substrate: the Case Study of Yarrowia lipolytica

Energy Technology Data Exchange (ETDEWEB)

Wang, Wei; Wei, Hui; Alahuhta, Markus; Zhang, Min; Himmel, Michael E.

2016-07-08

To achieve the goal of developing a direct microbial sugar conversion platform for the production of lipids and drop-in fuels from cellulosic biomass substrate, Yarrowia lipolytica was used to investigate its potential for being developed as CBP strain by expressing cellulase and xylanase enzymes. Y. lipolytica is known to accumulate lipids intracellularly and is capable of metabolizing glucose and xylose to produce lipids; however, due to the lack of the biomass degrading enzymes, it cannot directly utilize lignocellulosic substrates as carbon sources. While research is continuing on the development of a Y. lipolytica strain able to degrade cellulose, in this study, we present successful expression of several xylanases in Y. lipolytica. To the best of our knowledge, this is the first study introducing heterologous hemicellulose genes into the genome of Y. lipolytica. SDS-PAGE and western blotting analysis showed that the endo-xylanase gene XynII and exo-xylosidase gene XlnD were successfully expressed and secreted, and the expressed xylanases were likely either not or sparsely glycosylated, which is advantageous for expression of heterologous proteins from any species. Enzymatic activity tests further demonstrated active expression of XynII and XlnD in Y. lipolytica. Furthermore, synergistic action on converting xylan to xylose was observed when XlnD worked in concert with XynII. XlnD was able to work on the xylo-oligomers generated by XynII, enhancing the xylan conversion to monomeric xylose. The successful expression of these xylanases in Yarrowia further advances us towards our goal to develop a direct microbial conversion process using this organism. and xylose to produce lipids; however, due to the lack of the biomass degrading enzymes, it cannot directly utilize lignocellulosic substrates as carbon sources. While research is continuing on the development of a Y. lipolytica strain able to degrade cellulose, in this study, we present successful expression of

Investigation of the indigenous fungal community populating barley grains: Secretomes and xylanolytic potential

DEFF Research Database (Denmark)

Sultan, Abida; Frisvad, Jens Christian; Andersen, Birgit

2017-01-01

The indigenous fungal species populating cereal grains produce numerous plant cell wall-degrading enzymes including xylanases, which could play important role in plant-pathogen interactions and in adaptation of the fungi to varying carbon sources. To gain more insight into the grain surface......-associated enzyme activity, members of the populating fungal community were isolated, and their secretomes and xylanolytic activities assessed. Twenty-seven different fungal species were isolated from grains of six barley cultivars over different harvest years and growing sites. The isolated fungi were grown...... on medium containing barley flour or wheat arabinoxylan as sole carbon source. Their secretomes and xylanase activities were analyzed using SDS-PAGE and enzyme assays and were found to vary according to species and carbon source. Secretomes were dominated by cell wall degrading enzymes with xylanases...

Comparative evaluation of fermented and non-fermented de-oiled rice bran with or without exogenous enzymes supplementation in the diet of Labeo rohita (Hamilton, 1822).

Science.gov (United States)

Ranjan, Amit; Sahu, Narottam Prasad; Deo, Ashutosh Dharmendra; Kumar, H Sanath; Kumar, Sarvendra; Jain, Kamal Kant

2018-03-29

A 60-day feeding trial was conducted to study the effect of exogenous enzymes (xylanase and phytase) supplementation in the non-fermented and fermented de-oiled rice bran (DORB)-based diet of Labeo rohita. Four test diets (T1-DORB-based diet, T2-fermented DORB-based diet, T3-phytase and xylanase supplemented DORB-based diet, and T4-phytase and xylanase supplemented fermented DORB-based diet) were formulated and fed to the respective groups. Test diets T3 and T4 were supplemented with 0.01% xylanase (16,000 U kg -1 ) and 0.01% phytase (500 U kg -1 ) enzymes. One hundred twenty juveniles of L. rohita, with an average weight 5.01 ± 0.02 g, were stocked in 12 uniform size plastic rectangular tanks in triplicate with 10 fishes per tank following a completely randomized design (CRD). Exogenous enzyme supplementation to the T3 group significantly improved the growth performance of L. rohita (p exogenous enzymes. The carcass composition (except CP %), enzyme activities (except amylase activity), globulin, and A/G ratio did not vary significantly (p > 0.05). Based on the results of the present study, it is concluded that exogenous enzyme supplementation significantly increases the growth of fish fed with DORB-based diet.

Screening and Molecular Identification of New Microbial Strains for Production of Enzymes of Biotechnological Interest

Directory of Open Access Journals (Sweden)

Imen Ghazala

Full Text Available ABSTRACT: This research focused on isolation, identification and characterization of new strains of fungi and bacteria, which were able to produce extracellular xylanase, mannanase, pectinase and α-amylase. Fungi isolates were identified on the basis of analyses of 18S gene sequencing and internal transcribed spacer region. The closest phylogenetic neighbors according to 18S gene sequence and ITS region data for the two isolates M1 and SE were Aspergillus fumigatus and Aspergillus sydowii, respectively. I4 was identified as Bacillus mojavensis on the basis of the 16S rRNA gene sequencing and biochemical properties. The enzyme production was evaluated by cultivating the isolated microorganisms in liquid-state bioprocess using wheat bran as carbon source. Two fungi (M1, and SE and one bacterium (I4 strains were found to be xylanase producer, and several were proven to be outstanding producers of microbial xylanase. The strains producing xylanase secreted variable amounts of starch-debranching enzymes and produced low level β-mannan-degrading enzyme systems. The bacterium strain was found to be capable of producing pectinolytic enzymes on wheat bran at high level. Some of the strains have good potential for use as sources of important industrial enzymes.

DETERMINATION OF ENZYMES PRODUCED BY CERIPORIOPSIS SUBVERMISPORA DURING PRETREATMENT OF DIFFERENT BIOMASS SOURCES

Directory of Open Access Journals (Sweden)

Miroslav Ondrejovič

2012-02-01

Full Text Available The aim of this paper was to study of lignocellulolytic enzymes producing by Ceriporiopsis subvermispora during its cultivation on three types of plant biomass differentiated by chemical composition and physical properties (wheat straw, pine and poplar wood. The activity of lignocellulolytic enzymes in cultivation medium was determined by catalytic transformation of their natural substrates to products which were detected by photometric methods. Cellulase activities were very low while xylanases predominated. Wheat straw was best substrate for production of cellulases (4.38 U/mL and xylanases (23.34 U/mL. The maximum activity of cellulase and xylanase was reached at 8th and 3rd day, respectively. Laccase activity reached the maximum after 16 days and then gradually decreased. The best substrate for production of laccases was poplar wood (1.67 U/mL.

Towards a molecular understanding of symbiont function: Identification of a fungal gene for the degradation of xylan in the fungus gardens of leaf-cutting ants

Directory of Open Access Journals (Sweden)

Lange Lene

2008-02-01

Full Text Available Abstract Background Leaf-cutting ants live in symbiosis with a fungus that they rear for food by providing it with live plant material. Until recently the fungus' main inferred function was to make otherwise inaccessible cell wall degradation products available to the ants, but new studies have shed doubt on this idea. To provide evidence for the cell wall degrading capacity of the attine ant symbiont, we designed PCR primers from conserved regions of known xylanase genes, to be used in PCR with genomic DNA from the symbiont as template. We also measured xylanase, cellulase and proteinase activities in the fungus gardens in order to investigate the dynamics of degradation activities. Results We cloned a xylanase gene from the mutualistic fungus of Acromyrmex echinatior, determined its protein sequence, and inserted it in a yeast expression vector to confirm its substrate specificity. Our results show that the fungus has a functional xylanase gene. We also show by lab experiments in vivo that the activity of fungal xylanase and cellulase is not evenly distributed, but concentrated in the lower layer of fungus gardens, with only modest activity in the middle layer where gongylidia are produced and intermediate activity in the newly established top layer. This vertical distribution appears to be negatively correlated with the concentration of glucose, which indicates a directly regulating role of glucose, as has been found in other fungi and has been previously suggested for the ant fungal symbiont. Conclusion The mutualistic fungus of Acromyrmex echinatior has a functional xylanase gene and is thus presumably able to at least partially degrade the cell walls of leaves. This finding supports a saprotrophic origin of the fungal symbiont. The observed distribution of enzyme activity leads us to propose that leaf-substrate degradation in fungus gardens is a multi-step process comparable to normal biodegradation of organic matter in soil ecosystems

Identification of Pectin Degrading Enzymes Secreted by Xanthomonas oryzae pv. oryzae and Determination of Their Role in Virulence on Rice

OpenAIRE

Tayi, Lavanya; Maku, Roshan V.; Patel, Hitendra Kumar; Sonti, Ramesh V.

2016-01-01

Xanthomonas oryzae pv.oryzae (Xoo) causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs) like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we have identified some of the pectin degrading enzymes of Xoo and assessed their role in virulence. Bi...

Plant cell-wall hydrolyzing enzymes from indigenously isolated fungi grown on conventional and novel natural substrates

International Nuclear Information System (INIS)

Kumari, D.; Sohail, M.; Jahangeer, S.; Abideen, Z.; Khan, M.A.

2017-01-01

Fungi elaborate a variety of plant-hydrolyzing enzymes including cellulases, xylanases, pectinases and amylases. Although these enzymes have potential biotechnological applications, their production at industrial level is limited because of higher costs of the purified substrates. Hence, the present study was aimed to explore the novel, natural and cheaper substrates for enzyme production. Indigenously isolated fungal strains of Aspergillus sp. were grown on banana-peels, grapefruit-peels, pomegranate-peels, sugarcane bagasse, Eucalyptus camaldulensis-leaves and shoots of two halophytic plants including Halopyrum mucronatum and Desmostachya bipinnata under solid-state fermentation (SSF) and submerged fermentation (Smf) conditions. The crude enzyme preparation was screened for cellulase (endoglucanase, beta-glucosidase and filter-paperase), hemicellulase (xylanase), pectinase and amylase production. The results revealed that among all investigated enzymes, the xylanase titers were highest using D. bipinnata- shoots and H. mucronatum- shoots as substrates under solid state fermentation conditions, suggesting their exploitation at commercial scale. (author)

Investigation of the indigenous fungal community populating barley grains: Secretomes and xylanolytic potential.

Science.gov (United States)

Sultan, Abida; Frisvad, Jens C; Andersen, Birgit; Svensson, Birte; Finnie, Christine

2017-10-03

The indigenous fungal species populating cereal grains produce numerous plant cell wall-degrading enzymes including xylanases, which could play important role in plant-pathogen interactions and in adaptation of the fungi to varying carbon sources. To gain more insight into the grain surface-associated enzyme activity, members of the populating fungal community were isolated, and their secretomes and xylanolytic activities assessed. Twenty-seven different fungal species were isolated from grains of six barley cultivars over different harvest years and growing sites. The isolated fungi were grown on medium containing barley flour or wheat arabinoxylan as sole carbon source. Their secretomes and xylanase activities were analyzed using SDS-PAGE and enzyme assays and were found to vary according to species and carbon source. Secretomes were dominated by cell wall degrading enzymes with xylanases and xylanolytic enzymes being the most abundant. A 2-DE-based secretome analysis of Aspergillus niger and the less-studied pathogenic fungus Fusarium poae grown on barley flour and wheat arabinoxylan resulted in identification of 82 A. niger and 31 F. poae proteins many of which were hydrolytic enzymes, including xylanases. The microorganisms that inhabit the surface of cereal grains are specialized in production of enzymes such as xylanases, which depolymerize plant cell walls. Integration of gel-based proteomics approach with activity assays is a powerful tool for analysis and characterization of fungal secretomes and xylanolytic activities which can lead to identification of new enzymes with interesting properties, as well as provide insight into plant-fungal interactions, fungal pathogenicity and adaptation. Understanding the fungal response to host niche is of importance to uncover novel targets for potential symbionts, anti-fungal agents and biotechnical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Direct production of feruloyl oligosaccharides and hemicellulase inducement and distribution in a newly isolated Aureobasidium pullulans strain.

Science.gov (United States)

Yu, Xiao-hong; Gu, Zhen-xin

2014-02-01

Studies were carried out to screen and identify strains that are able to directly produce ferulic oligosaccharides (FOs) from wheat bran (WB). The inducement and distribution of hemicellulases from strain 2012, which was identified as a non-melanin secreting strain of Aureobasidium pullulans (A. pullulans), were also determined. In a 60 g/L WB solution, A. pullulans could produce 545 nmol/L FOs, 64.12 IU/mL xylanase and 0.14 IU/mL ferulic acid esterase (FAE). A. pullulans was cultivated in media with WB, glucose, xylose, sucrose, lactose or xylan as the carbon source, and hemicellulases were mainly induced by xylan and WB and inhibited by glucose and sucrose. Xylanase and FAE were mainly present in the culture filtrate, xylosidase in the hyphal filaments and arabinofuranosidase was a membrane-bound enzyme. The yield of FOs was positively correlated to the hemicellulases activity, and significantly positively (P < 0.05) correlated to the xylanase activity (r = 0.992).

Corn and soybean meal metabolizable energy with the addition of exogenous enzymes for poultry

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LRB Dourado

2009-03-01

Full Text Available Two metabolism assays were carried out to determine corn and soybean meal metabolizable energy when enzymes were added. In the first trial, 35 cockerels per studied feedstuff (corn and soybean meal were distributed in a completely randomized experimental design with four treatments of seven replicates of one bird each. The evaluated treatments were: ingredient (corn and soybean meal with no enzyme addition, with the addition of an enzyme complex (xylanase, amylase, protease - XAP, xylanase, or phytase. Precise feeding method was used to determine true metabolizable energy corrected for nitrogen balance (TMEn. The use of enzymes did not result in any differences (p>0.05 in soybean meal TMEn, but phytase improved corn TMEn in 2.3% (p=0.004. In the second trial, 280 seven-day-old broiler chicks were distributed in a completely randomized experimental design with seven treatments of five replicates of eight birds each. Treatments consisted of corn with no enzyme addition or with the addition of amylase, xylanase, phytase, XAP complex, XAP+phytase combination, or xylanase/ pectinase/β-glucanase complex (XPBG. Corn was supplemented with macro and trace minerals. Total excreta collection was used to determine apparent metabolizable energy corrected for nitrogen balance (AMEn. Differences were observed (p=0.08 in AMEn and dry matter metabolizability coefficient (p=0.03. The combination of the XAP complex with phytase promoted a 2.11% increase in corn AMEn values, and the remaining enzymes allowed increased between 0.86% and 1.66%.

Two-stage in vitro digestibility assay, a tool for formulating non-starch polysaccharide degrading enzyme combinations for commonly used feed ingredients of poultry rations

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Y. Ramana Reddy

2013-05-01

Full Text Available Aim: An attempt was made to assess the effect of pure enzyme combinations with the objective of formulating customized enzyme mixtures based on sugar release when subjected to two-stage in vitro digestion assay. Materials and Methods: A two-stage in vitro digestibility assay was carried out for commonly used feed ingredients for poultry viz., maize, soy bean meal, sunflower cake, and de-oiled rice bran supplemented with three concentrations of xylanase (5000; 7500 and 10000 IU/kg, cellulase (50; 100 and 400 IU/kg and â-D-glucanase (100; 200 and 400 IU/kg were used to formulate various NSP enzymes combinations. In total 27 NSP enzyme combinations (3x3x3 were formulated and the sugar released due to NSP digestion was quantified by phenol sulphuric acid method. Results: The total sugar release was significantly (P<0.05 higher with supplementation of various enzymes combinations for maize, sunflower cake and de-oiled rice bran where as no significant (P<0.05 interaction of various NSP enzymes combinations was observed for soy bean meal. The NSP digestibility was highest in combination (xylanase-5000, cellulase-50 and â-D-glucanase-400 IU/kg, (xylanase-10000, cellulase-50 and â-D-glucanase-200 IU/kg and (xylanase-7500, cellulase- 100 and â-D-glucanase-100 IU/kg for maize, sunflower cake and de-oiled rice bran respectively. In case of sunflower cake, significant (P<0.01 three way interaction was observed among the xylanase, cellulose, and â-D-glucanase enzymes and the two-way interactions between the enzymes were also significant (P<0.01. Conclusion: It is concluded that 'n' number of non-starch Polysaccharide enzymes combinations can be screened for their efficiency to digest non-starch Polysaccharides present in various feed ingredients commonly used in poultry rations by employing two-stage in vitro digestibility assay as a tool. [Vet World 2013; 6(8.000: 525-529

The ACEII recombinant Trichoderma reesei QM9414 strains with enhanced xylanase production and its applications in production of xylitol from tree barks.

Science.gov (United States)

Xiong, Lili; Kameshwar, Ayyappa Kumar Sista; Chen, Xi; Guo, Zhiyun; Mao, Canquan; Chen, Sanfeng; Qin, Wensheng

2016-12-28

ACEII transcription factor plays a significant role in regulating the expression of cellulase and hemicellulase encoding genes. Apart from ACEII, transcription factors such as XYR1, CRE1, HAP2/3/5 complex and ACEI function in a coordinated pattern for regulating the gene expression of cellulases and hemicellulases. Studies have demonstrated that ACEII gene deletion results in decreased total cellulase and xylanase activities with reduced transcript levels of lignocellulolytic enzymes. In this study, we have successfully transformed the ACEII transcription factor encoding gene in Trichoderma reesei to significantly improve its degrading abilities. Transformation experiments on parental strain T. reesei QM9414 has resulted in five genetically engineered strains T/Ace2-2, T/Ace2-5, T/Ace2-8, T/Ace5-4 and T/Ace10-1. Among which, T/Ace2-2 has exhibited significant increase in enzyme activity by twofolds, when compared to parental strain. The T/Ace2-2 was cultured on growth substrates containing 2% bark supplemented with (a) sugar free + MA medium (b) glucose + MA medium and (c) xylose + MA medium. The bark degradation efficiency of genetically modified T/Ace2-2 strain was assessed by analyzing the xylitol production yield using HPAEC. By 6th day, about 10.52 g/l of xylitol was produced through enzymatic conversion of bark (2% bark + MA + xylose) by the T/Ace2-2 strain and by 7th day the conversion rate was found to be 0.21 g/g. Obtained results confirmed that bark growth medium supplemented with D-xylose has profoundly increased the conversion rate of bark by T/Ace2-2 strain when compared to sugar free and glucose supplemented growth media. Results obtained from scanning electron microscopy has endorsed our current results. Bark samples inoculated with T/Ace2-2 strain has showed large number of degraded cells with clearly visible cavities and fractures, by exposing the microfibrillar interwoven complex. We propose a cost effective and ecofriendly method for

Enzymes improve ECF bleaching of pulp

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Lachenal, D.

2006-07-01

Full Text Available The delignification efficiency of different laccase enzymes was examined on the eucalyptus Kraft pulp. The laccase enzyme from Trametes versicolor showing the highest delignification efficiency was selected and used in the elemental chlorine-free bleaching sequence for improving the pulp bleachability. An appreciable reduction in chlorine dioxide consumption was also obtained. Further reduction in chlorine dioxide consumption was obtained when the same laccase treated pulp was subjected to an acid treatment after the extraction stage followed by the DEPD sequence. Elemental-chlorine free bleaching was also performed using the xylanase-laccase treated pulp. Xylanase treatment was incorporated to the laccase mediator system in the elemental-chlorine free bleaching both sequentially and simultaneously. The bleaching sequence DEPD followed and in both the cases, the reduction in chlorine dioxide consumption was greater in comparison to the control. The chlorine dioxide consumption was reduced further when xylanase-laccase treated pulp was given an additional acid treatment. The final pulp properties of the treated pulps were comparable to the control pulp.

Effects of Two-stage Controlled pH and Temperature vs. One-step Process for Hemicellulase Biosynthesis and Feruloyl Oligosaccharide Fermentation using Aureobasidium pullulans

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Xiaohong Yu

2016-04-01

Full Text Available A two-stage, pH- and temperature-controlled wheat bran fermentation method using Aureobasidium pullulans was investigated for feruloyl oligosaccharides (FOs production and the activities of xylanase, xylosidase, and ferulic acid esterase (FAE. A. pullulans secreted xylanase, xylosidase, and FAE at high levels in the initial pH of 4.0 to 5.0 and a fermentation liquid temperature of 31 °C to 33 °C. FOs production via two-stage fermentation (FOs 2 reached 1123 nmol/L after fermentation for 96 h, by controlling the initial pH at 4.0 and the initial temperature at 33 °C, and then changing the pH to 6.0 and the temperature to 29 °C at the same time at 36 h. This process was 12 h shorter and 219 nmol/L higher than a one-stage fermentation for producing FOs 1. Xylanase, xylosidase, and FAE activities were highly correlated with controlled pH and temperature and FOs biosynthesis rate. Thus, the combination of two-stage controlled pH and temperature could support mass production of FOs.

Studies on the enzymes produced by Basidiomycetes. Part 1. The production of crude enzymes

Energy Technology Data Exchange (ETDEWEB)

Hong, J. S.; Kim, D.H.

1981-01-01

Cellulase, protease, and xylanase, formation by the basidiomycetes, Pleurotus ostreatus 301 and Lentinus edodes 3-1 in growth on rice straw medium were studied. Cultural conditions adequate for enzyme production and effects of various materials and inorganic salts added to the rice straw media were investigated. Lentinus edodes 3-1 was an excellent producer of cellulase and xylanase, and Pleurotus ostreatus 301 of protease. The optimum conditions for enzyme production were 30 degrees for cellulase production and at 25 degrees for xylanase and protease production, with 75% moisture content and initial pH of 5.0-6.0. The appropriate incubation times for enzyme production were 30 days and 35 days for Pleurotus ostreatus 301 and Lentinus edodes 3-1, respectively. Among the various materials added, defatted soybean, defatted rape seed, or defatted sesame were all effective in enzyme production but reduced mycelial growth. Rice bran was also effective, particularly at a 30% concentration. The addition of inorganic salts enhanced enzyme production. Among inorganic salts, the optimum concentration of CaCO3 was 5%, and that of CaSO4 was 2%.

Production of ethanol from wet oxidised wheat straw by Thermoanaerobacter mathranii

DEFF Research Database (Denmark)

Ahring, B.K.; Licht, D.; Schmidt, A.S.

1999-01-01

evaluated with respect to total sugars, xylose, and 2-furfural produced. The concentration of sugars tended to be highest in hydrolysates produced at high oxygen pressures, whereas the concentration of 2-furfural was lowest in hydrolysates produced at low oxygen pressures and high carbonate concentrations...... with the commercial enzyme Celluclast(R) or with acid hydrolysis improved the ethanol yield from the hydrolysates. Treatment with Pentopan(TH) Mono BG or Pulpzyme(R) HC, both endo-1,4-beta-xylanases, had no effect neither had co-cultivation with the xylanase-producing Dictyoglomus B4. (C) 1998 Published by Elsevier...

Examining the Potential of Plasma-Assisted Pretreated Wheat Straw for Enzyme Production by Trichoderma reesei

DEFF Research Database (Denmark)

Rodríguez Gómez, Divanery; Lehmann, Linda Olkjær; Schultz-Jensen, Nadja

2012-01-01

Plasma-assisted pretreated wheat straw was investigated for cellulase and xylanase production by Trichoderma reesei fermentation. Fermentations were conducted with media containing washed and unwashed plasma-assisted pretreated wheat straw as carbon source which was sterilized by autoclavation....... To account for any effects of autoclavation, a comparison was made with unsterilized media containing antibiotics. It was found that unsterilized washed plasma-assisted pretreated wheat straw (which contained antibiotics) was best suited for the production of xylanases (110 IU ml(-1)) and cellulases (0...... other nonrefined feedstocks suggests that plasma pretreated wheat straw is a promising and suitable substrate for cellulase and hemicellulase production....

Understanding thermostability and pH dependent properties of proteins

DEFF Research Database (Denmark)

Galberg, Pernille

The work performed in this thesis is part of a larger project (“Computational design of stable enzymes”) involving several research teams, which aimed to improve PROPKA (http://propka.ki.ku.dk) and to provide the scientific community with a computational protocol and associated PROPKA program......, which could be used for predicting mutations with expectation of increased thermostability at a certain pH value or a shifted pH activity optimum. The ability of a Bacillus circulans xylanase (BCX) mutant (N35D/A115E) to induce a decrease in pH activity optimum was evaluated by a pH dependent xylanase...

Producción y purificación parcial de enzimas hidrolíticas de Aspergillus ficuum en fermentación sólida sobre residuos agroindustriales

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Marcia Costa

2010-07-01

Full Text Available Título en inglés: Production and partial purification of Aspergillus ficuum hydrolytic enzymes in solid state fermentation of agroindustrial residues Resumen En el presente trabajo se describe la producción de las enzimas fitasa, celulasa, xilanasa y proteasa con Aspergillus ficuum cepa DSM 932 mediante fermentación en estado sólido (SSF usando torta de canola y pomaza de cranberry como sustratos. Como medida indirecta de la producción de las enzimas se usó en cada caso la actividad enzimática. la torta de canola resultó ser un mejor sustrato para fitasa, celulasa y xilanasa, en tanto que la pomaza de cranberry resultó ser un sustrato potencial para proteasa. Mediante ultrafiltración escalonada fue posible purificar parcialmente los extractos enzimáticos de fitasa, celulasas y xilanasas, obtenidos a partir de torta de canola. La fitasa resultó tener un tamaño >100 kDa, en tanto que las celulasas y xilanasas presentan actividad en los retenidos de 10, 30 y 50 kDa, lo que indicaría que las isoenzimas de ambos complejos tienen pesos moleculares que oscilan entre 10 y 100 kDa. Palabras clave: fermentación sólida; torta de canola; Aspergillus ficuum; fitasa; xilanasa. Abstract In this paper, describes the production of the enzymes phytase, cellulase, xylanase and protease by Aspergillus ficuum DSM 932 strain, in solid state fermentation (SSF using canola cake and cranberry pomace as substrates. The enzyme activity was used in each case as an indirect measure of the enzymes production. Canola meal turned out to be a better substrate for phytase, cellulase and xylanase, while cranberry pomace was found to be a potential substrate for protease. Various ultrafiltration operations were carried out, decreasing the cut off membranes out in order to purify partially extracts of enzymes phytase, cellulase and xylanase, obtained from canola meal. Phytase was found to have a size >100 kDa, whereas cellulase and xylanase activity present in the

Characterization of lignocellulolytic activities from fungi isolated from the deep-sea sponge Stelletta normani.

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Ramón Alberto Batista-García

Full Text Available Extreme habitats have usually been regarded as a source of microorganisms that possess robust proteins that help enable them to survive in such harsh conditions. The deep sea can be considered an extreme habitat due to low temperatures (<5°C and high pressure, however marine sponges survive in these habitats. While bacteria derived from deep-sea marine sponges have been studied, much less information is available on fungal biodiversity associated with these sponges. Following screening of fourteen fungi isolated from the deep-sea sponge Stelletta normani sampled at a depth of 751 metres, three halotolerant strains (TS2, TS11 and TS12 were identified which displayed high CMCase and xylanase activities. Molecular based taxonomic approaches identified these strains as Cadophora sp. TS2, Emericellopsis sp. TS11 and Pseudogymnoascus sp. TS 12. These three fungi displayed psychrotolerance and halotolerant growth on CMC and xylan as sole carbon sources, with optimal growth rates at 20°C. They produced CMCase and xylanase activities, which displayed optimal temperature and pH values of between 50-70°C and pH 5-8 respectively, together with good thermostability and halotolerance. In solid-state fermentations TS2, TS11 and TS12 produced CMCases, xylanases and peroxidase/phenol oxidases when grown on corn stover and wheat straw. This is the first time that CMCase, xylanase and peroxidase/phenol oxidase activities have been reported in these three fungal genera isolated from a marine sponge. Given the biochemical characteristics of these ligninolytic enzymes it is likely that they may prove useful in future biomass conversion strategies involving lignocellulosic materials.

Characterization of lignocellulolytic activities from fungi isolated from the deep-sea sponge Stelletta normani.

Science.gov (United States)

Batista-García, Ramón Alberto; Sutton, Thomas; Jackson, Stephen A; Tovar-Herrera, Omar Eduardo; Balcázar-López, Edgar; Sánchez-Carbente, María Del Rayo; Sánchez-Reyes, Ayixon; Dobson, Alan D W; Folch-Mallol, Jorge Luis

2017-01-01

Extreme habitats have usually been regarded as a source of microorganisms that possess robust proteins that help enable them to survive in such harsh conditions. The deep sea can be considered an extreme habitat due to low temperatures (<5°C) and high pressure, however marine sponges survive in these habitats. While bacteria derived from deep-sea marine sponges have been studied, much less information is available on fungal biodiversity associated with these sponges. Following screening of fourteen fungi isolated from the deep-sea sponge Stelletta normani sampled at a depth of 751 metres, three halotolerant strains (TS2, TS11 and TS12) were identified which displayed high CMCase and xylanase activities. Molecular based taxonomic approaches identified these strains as Cadophora sp. TS2, Emericellopsis sp. TS11 and Pseudogymnoascus sp. TS 12. These three fungi displayed psychrotolerance and halotolerant growth on CMC and xylan as sole carbon sources, with optimal growth rates at 20°C. They produced CMCase and xylanase activities, which displayed optimal temperature and pH values of between 50-70°C and pH 5-8 respectively, together with good thermostability and halotolerance. In solid-state fermentations TS2, TS11 and TS12 produced CMCases, xylanases and peroxidase/phenol oxidases when grown on corn stover and wheat straw. This is the first time that CMCase, xylanase and peroxidase/phenol oxidase activities have been reported in these three fungal genera isolated from a marine sponge. Given the biochemical characteristics of these ligninolytic enzymes it is likely that they may prove useful in future biomass conversion strategies involving lignocellulosic materials.

Hydrolysis of lignocellulosic feedstock by novel cellulases originating from Pseudomonas sp. CL3 for fermentative hydrogen production.

Science.gov (United States)

Cheng, Chieh-Lun; Chang, Jo-Shu

2011-09-01

A newly isolated indigenous bacterium Pseudomonas sp. CL3 was able to produce novel cellulases consisting of endo-β-1,4-d-glucanase (80 and 100 kDa), exo-β-1,4-d-glucanase (55 kDa) and β-1,4-d-glucosidase (65 kDa) characterized by enzyme assay and zymography analysis. In addition, the CL3 strain also produced xylanase with a molecular weight of 20 kDa. The optimal temperature for enzyme activity was 50, 45, 45 and 55 °C for endo-β-1,4-d-glucanase, exo-β-1,4-d-glucanase, β-1,4-d-glucosidase and xylanase, respectively. All the enzymes displayed optimal activity at pH 6.0. The cellulases/xylanase could hydrolyze cellulosic materials very effectively and were thus used to hydrolyze natural agricultural waste (i.e., bagasse) for clean energy (H2) production by Clostridium pasteurianum CH4 using separate hydrolysis and fermentation process. The maximum hydrogen production rate and cumulative hydrogen production were 35 ml/L/h and 1420 ml/L, respectively, with a hydrogen yield of around 0.96 mol H2/mol glucose. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effect of amount of straw provided to growing/finishing pigs on gastric ulceration at slaughter

DEFF Research Database (Denmark)

Herskin, Mette S.; Jensen, Henrik Elvang; Jespersen, Anna

2014-01-01

The effect of a current commercial xylanase (DAN) and experimental xylanase (EX), and EX in combination with protease (EXP), on the degradation and apparent ileal digestibility (AID) of non-starch polysaccharides (NSP) in wheat Distillers Dried Grains with Solubles (DDGS), was studied in 8 ileum......-cannulated pigs (initial BW 36.6±2.8 kg) following a double 4x4 Latin Square design. The control and three enzyme diets, each containing 96% DDGS, were supplemented with vitamins, minerals, L-lysine, 500 FTU phytase/kg feed, dust-binder and chromic oxide (3 g/kg). The pigs were fed 3 times daily for 1 week...

Enzymes in Commercial Cellulase Preparations Bind Differently to Dioxane Extracted Lignins

Energy Technology Data Exchange (ETDEWEB)

Yarbrough, John M.; Mittal, Ashutosh; Katahira, Rui; Mansfield, Elisabeth; Taylor, Larry E.; Decker, Stephen R.; Himmel, Michael E.; Vinzant, Todd

2017-04-24

Commercial fungal cellulases used in biomass-to-biofuels processes can be grouped into three general classes: native, augmented, and engineered. To evaluate lignin binding affinities of different enzyme activities in various commercial cellulase formulations in order to determine if enzyme losses due to lignin binding can be modulated by using different enzymes of the same activity We used water:dioxane (1:9) to extract lignin from pretreated corn stover. Commercial cellulases were incubated with lignin and the unbound supernatants were evaluated for individual enzyme loss by SDS=PAGE and these were correlated with activity loss using various pNP-sugar substrates. Colorimetric assays for general glycosyl hydrolase activities showed distinct differences in enzyme binding to lignin for each enzyme activity. Native systems demonstrated low binding of endo- and exo-cellulases, high binding of xylanase, and moderate ..beta..-glucosidase binding. Engineered cellulase mixtures exhibited low binding of exo-cellulases, very strong binding of endocellulases and ..beta..- glucosidase, and mixed binding of xylanase activity. The augmented cellulase had low binding of exocellulase, high binding of endocellulase and xylanase, and moderate binding of ..beta..-glucosidase activities. Bound and unbound activities were correlated with general molecular weight ranges of proteins as measured by loss of proteins bands in bound fractions on SDS-PAGE gels. Lignin-bound high molecular weight bands correlated with binding of ..beta..-glucosidase activity. While ..beta..-glucosidases demonstrated high binding in many cases, they have been shown to remain active. Bound low molecular weight bands correlated with xylanase activity binding. Contrary to other literature, exocellulase activity did not show strong lignin binding. The variation in enzyme activity binding between the three classes of cellulases preparations indicate that it is certainly possible to alter the binding of specific

Combined enzymatic and physical deinking methodology for efficient eco-friendly recycling of old newsprint.

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Antar Puneet Virk

Full Text Available BACKGROUND: The development in the deinking process has made recycled fiber a major part of the raw material for pulp and paper industry. Enzymes have revolutionized the deinking process obtaining brightness levels surpassing conventional deinking processes. This study explores the deinking efficiencies of bacterial alkalophilic laccase (L and xylanase (X enzymes along with physical deinking methods of microwaving (MW and sonication (S for recycling of old newsprint (ONP. METHODS AND RESULTS: The operational parameters viz. enzyme dose, pH and treatment time for X and L deinking were optimized statistically using Response Surface Methodology. Laccase did not require any mediator supplementation for deinking. Deinking of ONP pulp with a combination of xylanase and laccase enzymes was investigated, and fiber surface composition and morphological changes were studied using X-ray diffraction, fourier transform infrared spectroscopy and scanning electron microscopy. Compared to the pulp deinked with xylanase (47.9% or laccase (62.2% individually, the percentage reduction of effective residual ink concentration (ERIC was higher for the combined xylanase/laccase-deinked pulp (65.8%. An increase in brightness (21.6%, breaking length (16.5%, burst factor (4.2% tear factor (6.9%, viscosity (13% and cellulose crystallinity (10.3% along with decrease in kappa number (22% and chemical consumption (50% were also observed. Surface appeared more fibrillar along with changes in surface functional groups. A combination of physical and enzymatic processes (S-MW-XL for deinking further improved brightness (28.8% and decreased ERIC (73.9% substantially. CONCLUSION: This is the first report on deinking of ONP with laccase without any mediator supplementation. XL pretreatment resulted in marked improvement in paper quality and a new sequence being reported for deinking (S-MW-XL will contribute further in decreasing chemical consumption and making the process

ETHANOL PRECIPITATION OF GLYCOSYL HYDROLASES PRODUCED BY Trichoderma harzianum P49P11

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M. A. Mariño

2015-06-01

Full Text Available AbstractThis study aimed to concentrate glycosyl hydrolases produced by Trichoderma harzianum P49P11 by ethanol precipitation. The variables tested besides ethanol concentration were temperature and pH. The precipitation with 90% (v/v ethanol at pH 5.0 recovered more than 98% of the xylanase activity, regard less of the temperature (5.0, 15.0, or 25.0 °C. The maximum recovery of cellulase activity as FPase was 77% by precipitation carried out at this same pH and ethanol concentration but at 5.0 °C. Therefore, ethanol precipitation can be considered to be an efficient technique for xylanase concentration and, to a certain extent, also for the cellulase complex.

Effect of peat extract on the hydrolytic enzymes of Phanerochaete chrysosporium

Energy Technology Data Exchange (ETDEWEB)

Nawaz, M; Gunasekaran, M

1988-08-01

Peat, a partially decomposed plant material rich in minerals and lignocellulose was tested as a substrate for the growth and production of hydrolytic enzymes viz. cellulase, cellobiase and xylanase in Phanerochaete chrysosporium. Three types of peat extracts such as cold, hot water and autoclaved were prepared and tested. Among them, autoclaved extract supported the maximal growth. The intracellular enzyme activities peaked on the fifth day after inoculation irrespective of the media and enzyme tested. Addition of cellobiose and lactose in the medium induced the production of cellulase, xylanase and to a lesser extent cellobiase. Addition of glucose and sucrose to the media resulted in the suppression of all the extracellular enzymes tested. 18 refs., 5 figs.

Production of Cellulolytic and Hemicellulolytic Enzymes From Aureobasidium pulluans on Solid State Fermentation

Science.gov (United States)

Leite, Rodrigo Simões Ribeiro; Bocchini, Daniela Alonso; da Silva Martins, Eduardo; Silva, Dênis; Gomes, Eleni; da Silva, Roberto

This article investigates a strain of the yeast Aureobasidium pullulans for cellulase and hemicellulase production in solid state fermentation. Among the substrates analyzed, the wheat bran culture presented the highest enzymatic production (1.05 U/mL endoglucanase, 1.3 U/mL β-glucosidase, and 5.0 U/mL xylanase). Avicelase activity was not detected. The optimum pH and temperature for xylanase, endoglucanase and β-glucosidase were 5.0 and 50, 4.5 and 60, 4.0 and 75°C, respectively. These enzymes remained stable between a wide range of pH. The β-glucosidase was the most thermostable enzyme remaining 100% active when incubated at 75°C for 1 h.

Isolation, cloning and molecular characterization of a thermotolerant ...

African Journals Online (AJOL)

Isolation, cloning and molecular characterization of a thermotolerant xylanase from Streptomyces sp. THW31. Thayat Sriyapai, Peechapack Somyoonsap, Supatra Areekit, Paisarn Khawsak, Arda Pakpitcharoen, Kosum Chansiri ...

Properties of Enzyme Pretreated Wikstroemia sikokiana and Broussonetia papyrifera Bast Fiber Pulps

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Lang-Dong Lin

2015-04-01

Full Text Available Xylanase, pectinase complex, and BL11 pectinase were employed for the pretreatment of gampi and paper mulberry bast fiber pulps prior to chlorine dioxide bleaching. The bleaching efficiencies of the pulps with different enzymatic pretreatments were investigated. Accelerated aging by heat-humidity treatment was also conducted to evaluate yellowing phenomena and to estimate the prevention of brightness reversion (brightness retention by enzymatic pretreatment. The order of active chlorine required with respect to pretreatment was pectinase complex > xylanase > BL11 pectinase for soda and soda/oxalate gampi pulps and pectinase complex > BL11 pectinase > xylanase for soda and soda/oxalate paper mulberry pulps. Higher brightness retention values were observed for soda/oxalate pulps compared to soda pulps. The brightness retention levels for gampi pulps and mulberry pulps after ClO2 bleaching with enzymatic pretreatment were higher than the levels of ClO2 and NaClO bleaching pulps. Enzymatic treatments were thus able to reduce the usage of ClO2 and to assist in producing photo-stable paper materials for art and artifact-repairing applications. Thus, enzymatic pretreatment of the pulp has the potential to meet world trends and environmental sustainability for pulp and paper industries.

Mixed submerged fermentation with two filamentous fungi for cellulolytic and xylanolytic enzyme production.

Science.gov (United States)

Garcia-Kirchner, O; Muñoz-Aguilar, M; Pérez-Villalva, R; Huitrón-Vargas, C

2002-01-01

The efficient saccharification of lignocellulosic materials requires the cooperative actions of different cellulase enzyme activities: exoglucanase, endoglucanase, beta-glucosidase, and xylanase. Previous studies with the fungi strains Aureobasidium sp. CHTE-18, Penicillium sp. CH-TE-001, and Aspergillus terreus CH-TE-013, selected mainly because of their different cellulolytic and xylanolytic activities, have demonstrated the capacity of culture filtrates of cross-synergistic action in the saccharification of native sugarcane bagasse pith. In an attempt to improve the enzymatic hydrolysis of different cellulosic materials, we investigated a coculture fermentation with two of these strains to enhance the production of cellulases and xylanases. The 48-h batch experimental results showed that the mixed culture of Penicillium sp. CH-TE-001 and A. terreus CH-TE-013 produced culture filtrates with high protein content, cellulase (mainly beta-glucosidase), and xylanase activities compared with the individual culture of each strain. The same culture conditions were used in a simple medium with mineral salts, corn syrup liquor, and sugarcane bagasse pith as the sole carbon source with moderate shaking at 29 degrees C. Finally, we compared the effect of the cell-free culture filtrates obtained from the mixed and single fermentations on the saccharification of different kinds of cellulosic materials.

Unravelling the Interactions between Hydrolytic and Oxidative Enzymes in Degradation of Lignocellulosic Biomass by Sporothrix carnis under Various Fermentation Conditions

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Olusola A. Ogunyewo

2016-01-01

Full Text Available The mechanism underlying the action of lignocellulolytic enzymes in biodegradation of lignocellulosic biomass remains unclear; hence, it is crucial to investigate enzymatic interactions involved in the process. In this study, degradation of corn cob by Sporothrix carnis and involvement of lignocellulolytic enzymes in biodegradation were investigated over 240 h cultivation period. About 60% degradation of corn cob was achieved by S. carnis at the end of fermentation. The yields of hydrolytic enzymes, cellulase and xylanase, were higher than oxidative enzymes, laccase and peroxidase, over 144 h fermentation period. Maximum yields of cellulase (854.4 U/mg and xylanase (789.6 U/mg were at 96 and 144 h, respectively. Laccase and peroxidase were produced cooperatively with maximum yields of 489.06 U/mg and 585.39 U/mg at 144 h. Drastic decline in production of cellulase at 144 h (242.01 U/mg and xylanase at 192 h (192.2 U/mg indicates that they play initial roles in biodegradation of lignocellulosic biomass while laccase and peroxidase play later roles. Optimal degradation of corn cob (76.6% and production of hydrolytic and oxidative enzymes were achieved with 2.5% inoculum at pH 6.0. Results suggest synergy in interactions between the hydrolytic and oxidative enzymes which can be optimized for improved biodegradation.

Enzymatic activities produced by mixed Saccharomyces and non-Saccharomyces cultures: relationship with wine volatile composition.

Science.gov (United States)

Maturano, Yolanda Paola; Assof, Mariela; Fabani, María Paula; Nally, María Cristina; Jofré, Viviana; Rodríguez Assaf, Leticia Anahí; Toro, María Eugenia; Castellanos de Figueroa, Lucía Inés; Vazquez, Fabio

2015-11-01

During certain wine fermentation processes, yeasts, and mainly non-Saccharomyces strains, produce and secrete enzymes such as β-glucosidases, proteases, pectinases, xylanases and amylases. The effects of enzyme activity on the aromatic quality of wines during grape juice fermentation, using different co-inoculation strategies of non-Saccharomyces and Saccharomyces cerevisiae yeasts, were assessed in the current study. Three strains with appropriate enological performance and high enzymatic activities, BSc562 (S. cerevisiae), BDv566 (Debaryomyces vanrijiae) and BCs403 (Candida sake), were assayed in pure and mixed Saccharomyces/non-Saccharomyces cultures. β-Glucosidase, pectinase, protease, xylanase and amylase activities were quantified during fermentations. The aromatic profile of pure and mixed cultures was determined at the end of each fermentation. In mixed cultures, non-Saccharomyces species were detected until day 4-5 of the fermentation process, and highest populations were observed in MSD2 (10% S. cerevisiae/90% D. vanrijiae) and MSC1 (1% S. cerevisiae/99% C. sake). According to correlation and multivariate analysis, MSD2 presented the highest concentrations of terpenes and higher alcohols which were associated with pectinase, amylase and xylanase activities. On the other hand, MSC1 high levels of β-glucosidase, proteolytic and xylanolytic activities were correlated to esters and fatty acids. Our study contributes to a better understanding of the effect of enzymatic activities by yeasts on compound transformations that occur during wine fermentation.

Composition and microstructure alteration of triticale grain surface after processing by enzymes of cellulase complex

Directory of Open Access Journals (Sweden)

Elena Kuznetsova

2016-01-01

Full Text Available It is found that the pericarp tissue of grain have considerable strength and stiffness, that has an adverse effect on quality of whole-grain bread. Thereby, there exists the need for preliminary chemical and biochemical processing of durable cell walls before industrial use. Increasingly used in the production of bread finds an artificial hybrid of the traditional grain crops of wheat and rye - triticale, grain which has high nutritional value. The purpose of this research was to evaluate the influence of cellulose complex (Penicillium canescens enzymes on composition and microstructure alteration of triticale grain surface, for grain used in baking. Triticale grain was processed by cellulolytic enzyme preparations with different composition (producer is Penicillium canescens. During experiment it is found that triticale grain processing by enzymes of cellulase complex leads to an increase in the content of water-soluble pentosans by 36.3 - 39.2%. The total amount of low molecular sugars increased by 3.8 - 10.5 %. Studies show that under the influence of enzymes the microstructure of the triticale grain surface is changing. Microphotographs characterizing grain surface structure alteration in dynamic (every 2 hours during 10 hours of substrate hydrolysis are shown. It is found that the depth and direction of destruction process for non-starch polysaccharides of grain integument are determined by the composition of the enzyme complex preparation and duration of exposure. It is found, that xylanase involved in the modification of hemicelluloses fiber having both longitudinal and radial orientation. Hydrolysis of non-starch polysaccharides from grain shells led to increase of antioxidant activity. Ferulic acid was identified in alcoholic extract of triticale grain after enzymatic hydrolysis under the influence of complex preparation containing cellulase, xylanase and β-glucanase. Grain processing by independent enzymes containing in complex

InXy and SeXy, compact heterologous reporter proteins for mammalian cells.

Science.gov (United States)

Fluri, David A; Kelm, Jens M; Lesage, Guillaume; Baba, Marie Daoud-El; Fussenegger, Martin

2007-10-15

Mammalian reporter proteins are essential for gene-function analysis, drugscreening initiatives and as model product proteins for biopharmaceutical manufacturing. Bacillus subtilis can maintain its metabolism by secreting Xylanase A (XynA), which converts xylan into shorter xylose oligosaccharides. XynA is a family 11 xylanase monospecific for D-xylose containing substrates. Mammalian cells transgenic for constitutive expression of wild-type xynA showed substantial secretion of this prokaryotic enzyme. Deletion analysis confirmed that a prokaryotic signal sequence encoded within the first 81 nucleotides was compatible with the secretory pathway of mammalian cells. Codon optimization combined with elimination of the prokaryotic signal sequence resulted in an exclusively intracellular mammalian Xylanase A variant (InXy) while replacement by an immunoglobulin-derived secretion signal created an optimal secreted Xylanase A derivative (SeXy). A variety of chromogenic and fluorescence-based assays adapted for use with mammalian cells detected InXy and SeXy with high sensitivity and showed that both reporter proteins resisted repeated freeze/thaw cycles, remained active over wide temperature and pH ranges, were extremely stable in human serum stored at room temperature and could independently be quantified in samples also containing other prominent reporter proteins such as the human placental alkaline phosphatase (SEAP) and the Bacillus stearothermophilus-derived secreted alpha-amylase (SAMY). Glycoprofiling revealed that SeXy produced in mammalian cells was N- glycosylated at four different sites, mutation of which resulted in impaired secretion. SeXy was successfully expressed in a variety of mammalian cell lines and primary cells following transient transfection and transduction with adeno-associated virus particles (AAV) engineered for constitutive SeXy expression. Intramuscular injection of transgenic AAVs into mice showed significant SeXy levels in the bloodstream

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Indian Academy of Sciences (India)

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thesis, i.e., using light energy to fix CO. 2. ) is called ... required to convert polymeric constituents into soluble forms, suitable ... biomass as interconnected mycorrhizal hyphae. ... cellulase, xylanase, pectin methyl esterase, peroxidase and pro-.

Xylanolytic enzyme systems in Arthrobacter sp MTCC 5214 and Lactobacillus sp.

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, R.; Jalal, T.

The production of extracellular xylanolytic enzymes such as xylanase, alfa-L-arabinofuranosidase (alfa-l-AFase), and acetyl xylan esterase (Axe) by marine Arthrobacter sp and Lactobacillus sp was investigated using different carbon sources Induction...

Fungal enzyme production in seeds of transgenic canola plants for conversion of cellulosic materials to ethanol

Energy Technology Data Exchange (ETDEWEB)

Cheng, K.J.; Beauchemin, K.A. [Agriculture and Agri-Food Canada, Lethbridge, AB (Canada); Moloney, M.M. [Calgary Univ., AB (Canada). Dept. of Biological Sciences

1997-07-01

The fuel alcohol industry makes use of industrial enzymes to effectively degrade fibrous plant cell walls. Carbohydrates in cellulosic materials are in the form of complex sugars that can be hydrolyzed to simple sugars by fungal fibrolytic enzymes such as cellulases and xylanases. This study was conducted to find a cost effective way to produce fibrolytic enzymes using gene fusion technology in which a xylanase gene and a cellulase gene from two fungal species are introduced into canola to be a carrier for the production of these enzymes. The two genes had been analyzed for maximal enzymatic activity to minimize side effects. Results of the study demonstrated the stability and potential of transgenic oil-bodies as an immobilized enzyme matrix, and showed that it is possible to express fibrolytic enzymes in canola.

Seeing green bacteria in a new light: genomics-enabled studies of the photosynthetic apparatus in green sulfur bacteria and filamentous anoxygenic phototrophic bacteria

DEFF Research Database (Denmark)

Frigaard, Niels-Ulrik; Bryant, Donald A

2004-01-01

Based upon their photosynthetic nature and the presence of a unique light-harvesting antenna structure, the chlorosome, the photosynthetic green bacteria are defined as a distinctive group in the Bacteria. However, members of the two taxa that comprise this group, the green sulfur bacteria...... (Chlorobi) and the filamentous anoxygenic phototrophic bacteria ("Chloroflexales"), are otherwise quite different, both physiologically and phylogenetically. This review summarizes how genome sequence information facilitated studies of the biosynthesis and function of the photosynthetic apparatus...... a and carotenoid biosynthesis enzymes, gene cluster analysis in Cfx. aurantiacus, and gene inactivation studies in Chl. tepidum. Based on these results, BChl a and BChl c biosynthesis is similar in the two organisms, whereas carotenoid biosynthesis differs significantly. In agreement with its facultative anaerobic...

Production, purification and characterization of celullase-free ...

African Journals Online (AJOL)

STORAGESEVER

2008-11-05

Nov 5, 2008 ... enzymes, higher yield compared to yeast and bacteria and also the .... UV monitor. Fractions of 5 ml were ..... selective xylanase induction/repression in the different media used. .... mutant of Aspergillus ochraceus. Biotechnol.

The use of Amazon fungus ( Trametes sp.) in the production of ...

African Journals Online (AJOL)

The use of Amazon fungus (Trametes sp.) in the production of cellulase and xylanase. Salony Aquino Pereira, Rafael Lopes e Oliveira, Sergio Duvoisin Jr, Leonor Alves de Oliveira da Silva, Patrícia Melchionna Albuquerque ...

Transcriptional regulation of the xylanolytic enzyme system of Aspergillus

NARCIS (Netherlands)

Peij, van N.N.M.E.

1999-01-01

Filamentous fungi, such as Aspergillus niger , produce high levels of polysaccharide degrading enzymes and are frequently used as production organisms for industrial enzyme preparations. The application of these polysaccharidases as xylanases and cellulases comprises

Effect of degradation of xylan constituent in Mitsumata (Edgeworthia papyrifera Sieb. et Zucc. ) bast on its pulping by pectinolytic enzymes form Erwinia carotovora

Energy Technology Data Exchange (ETDEWEB)

Tanabe, Hiroyuki; Matsuo, Ryukichi; Kobayashi, Yoshinari

1988-01-01

Pulping of mitsumata (Edgeworthia papyrifera Sieb. et Zucc.) bast by the crude enzyme from a bacterium Erwinia carotovora FERM P-7576, was more effective by a stepwise treatment at pH 6.5 and subsequently at pH 9.5 and eluted greater amount of xylose constituent than a constant pH treatment at pH 9.5 where only the maceration enzymes, endo-pectate lyase and endo-pectin lyase, among the crude enzyme are operative. The crude enzymes obtained from the cultivation of this bacterial strain on mitsumata bast fibers were more effective for the stepwise pH pulping method than those from the cultivation on soluble pectin. Xylanase activity in the mitsumata bast-induced enzyme at pH 6.5 was twice as high as that in the soluble pectin-induced one. The activities of other hemicellulases and cellulase were, high as that in the soluble pectin-induced one. The activities of other hemicellulases and cellulase were, however, independent on the inducing materials. Purified exo-type xylanase prepared from the crude enzyme acted comparably to the entire crude enzyme in the first step of the combination pulping, but the xylanase per se showed no maceration activity. These results suggests that the degradation of xylan constituent within the bast fibers effects the acceleration of the subsequent enzymatic pulping by the pectinolytic maceration enzymes. The maceration mechanism involving xylan degradation was also discussed.

Extracellular enzyme activities during lignocellulose degradation by Streptomyces spp.: a comparative study of wild-type and genetically manipulated strains

International Nuclear Information System (INIS)

Ramachandra, M.; Crawford, D.L.; Pometto, A.L. III

1987-01-01

The wild-type ligninolytic actinomycete Streptomyces viridosporus T7A and two genetically manipulated strains with enhanced abilities to produce a water-soluble lignin degradation intermediate, an acid-precipitable polymeric lignin (APPL), were grown on lignocellulose in solid-state fermentation cultures. Culture filtrates were periodically collected, analyzed for APPL, and assayed for extracellular lignocellulose-catabolizing enzyme activities. Two APPL-overproducing strains, UV irradiation mutant T7A-81 and protoplast fusion recombinant SR-10, had higher and longer persisting peroxidase, esterase, and endoglucanase activities than did the wild-type strain T7A. Results implicated one or more of these enzymes in lignin solubilization. Only mutant T7A-81 had higher xylanase activity than the wild type. The peroxidase was induced by both lignocellulose and APPL. This extracellular enzyme has some similarities to previously described ligninases in fungi. This is the first report of such an enzyme in Streptomyces spp. Four peroxidase isozymes were present, and all catalyzed the oxidation of 3,4-dihydroxyphenylalanine, while one also catalyzed hydrogen peroxide-dependent oxidation of homoprotocatechuic acid and caffeic acid. Three constitutive esterase isozymes were produced which differed in substrate specificity toward α-naphthyl acetate and α-naphthyl butyrate. Three endoglucanase bands, which also exhibited a low level of xylanase activity, were identified on polyacrylamide gels as was one xylanase-specific band. There were no major differences in the isoenzymes produced by the different strains. The probable role of each enzyme in lignocellulose degradation is discussed

Morphogenesis and Production of Enzymes by Penicillium echinulatum in Response to Different Carbon Sources

Directory of Open Access Journals (Sweden)

Willian Daniel Hahn Schneider

2014-01-01

Full Text Available The effect of different carbon sources on morphology and cellulase and xylanase production of Penicillium echinulatum was evaluated in this work. Among the six carbon sources studied, cellulose and sugar cane bagasse were the most suitable for the production of filter paper activity, endoglucanases, xylanases, and β-glucosidases. However, sucrose and glucose showed β-glucosidase activities similar to those obtained with the insoluble sources. The polyacrylamide gels proved the enzymatic activity, since different standards bands were detected in the media mentioned above. Regarding morphology, it was observed that the mycelium in a dispersed form provided the greatest enzymatic activity, possibly due to greater interaction between the substrate and hyphae. These data are important in understanding the physiology of fungi and could contribute to obtaining enzyme with potential application in the technology of second generation ethanol.

The natural catalytic function of CuGE glucuronoyl esterase in hydrolysis of genuine lignin-carbohydrate complexes from birch

DEFF Research Database (Denmark)

Mosbech, Caroline; Holck, Jesper; Meyer, Anne S.

2018-01-01

Glucuronoyl esterases belong to carbohydrate esterase family 15 and catalyze de-esterification. Their natural function is presumed to be cleavage of ester linkages in lignin-carbohydrate complexes particularly those linking lignin and glucuronoyl residues in xylans in hardwood. Here, we show...... for the first time a detailed product profile of aldouronic acids released from birchwood lignin by a glucuronoyl esterase from the white-rot fungus Cerrena unicolor (CuGE). CuGE releases substrate for GH10 endo-xylanase which results in significantly increased product release compared to the action of endo......-xylanase alone. CuGE also releases neutral xylo-oligosaccharides that can be ascribed to the enzymes feruloyl esterase side activity as demonstrated by release of ferulic acid from insoluble wheat arabinoxylan. The data verify the enzyme's unique ability to catalyze removal of all glucuronoxylan associated...

Exploring the Plant–Microbe Interface by Profiling the Surface-Associated Proteins of Barley Grains

DEFF Research Database (Denmark)

Sultan, Abida; Andersen, Birgit; Svensson, Birte

2016-01-01

Cereal grains are colonized by a microbial community that actively interacts with the plant via secretion of various enzymes, hormones, and metabolites. Microorganisms decompose plant tissues by a collection of depolymerizing enzymes, including β-1,4-xylanases, that are in turn inhibited by plant...... xylanase inhibitors. To gain insight into the importance of the microbial consortia and their interaction with barley grains, we used a combined gel-based (2-DE coupled to MALDI-TOF-TOF MS) and gel-free (LC–MS/MS) proteomics approach complemented with enzyme activity assays to profile the surface......-associated proteins and xylanolytic activities of two barley cultivars. The surface-associated proteome was dominated by plant proteins with roles in defense and stress-responses, while the relatively less abundant microbial (bacterial and fungal) proteins were involved in cell-wall and polysaccharide degradation...

Biological nitrate removal from synthetic wastewater using a fungal ...

African Journals Online (AJOL)

2007-04-02

-stage ... grass, instead of non-autoclaved grass containing natural microbial consortia, as sup- ... 25ºC within a 20 ℓ plastic bag, along with a 1 ℓ conical flask ... of cellulases and xylanases – the two major hydrolytic enzyme.

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African Journals Online (AJOL)

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and xylanase/amylase was analyzed to determine their effects on dough rheology and bread quality. Seven bread .... cylinder (G Paniz, CS 390, São Paulo, Brazil). Each bread ..... Aamodt A, Magnus E, Faergestad E (2003). Effect of flour ...

Use of agricultural by-products for the production of xylitol. I. The production of xylose

Energy Technology Data Exchange (ETDEWEB)

De Menezes, H C

1976-01-01

A Rhizopus species capable of converting xylan into xylose was isolated from the soil, and purified. The xylanase produced by this fungus was capable of producing xylose from corn cob, wheat bran, and rice hulls without prior extraction of the xylan.

Xylanases of Anaerobic Fungus Anaeromyces mucronatus

Czech Academy of Sciences Publication Activity Database

Novotná, Zuzana; Procházka, J.; Šimůnek, Jiří; Fliegerová, Kateřina

2010-01-01

Roč. 55, č. 4 (2010), s. 363-367 ISSN 0015-5632 R&D Projects: GA ČR GD525/08/H060 Institutional research plan: CEZ:AV0Z50450515 Keywords : NEOCALLIMASTIX-FRONTALIS * XYLANOLYTIC ENZYMES * POLYCENTRIC FUNGI Subject RIV: GM - Food Processing Impact factor: 0.977, year: 2010

Diversity in production of xyaln-degrading enzymes among species belonging to the Trichoderma section Longibrachiatum

Science.gov (United States)

Xylan is an important part of plant biomass and represents a renewable raw material for biorefineries. Contrary to cellulose, the structure of hemicellulose is quite complex. Therefore, the biodegradation of xylan needs the cooperation of many enzymes. For industrial production of xylanase multienzy...

Diversity in Production of Xylan-Degrading Enzymes Among Species Belonging to the Trichoderma Section Longibrachiatum

NARCIS (Netherlands)

Toth, K.; Gool, van M.P.; Schols, H.A.; Samuels, G.J.; Gruppen, H.; Szakacs, G.

2013-01-01

Xylan is an important part of plant biomass and represents a renewable raw material for biorefineries. Contrary to cellulose, the structure of hemicellulose is quite complex. Therefore, the biodegradation of xylan needs the cooperation of many enzymes. For industrial production of xylanase

An innovative approach for hyperproduction of cellulolytic and ...

African Journals Online (AJOL)

The present work describes the production of cellulolytic enzymes and hemicellulolytic enzyme (xylanase) along with total extracellular protein by Aspergillus niger and Trichoderma viride using submerged fermentation. Among seven different kinds of experiments, secretion rate of protein and enzymes was investigated by ...

A molecular analysis of (hemi-)cellulose degradation by Aspergilli

NARCIS (Netherlands)

Gielkens, M.M.C.

1999-01-01

Glycosylhydrolases like cellulases and xylanases are of great importance for the ecological recycling of biomass. The saprophytic fungi, e.g Aspergillus niger , are capable of degrading plant cell wall material by secreting these enzymes. Because of their properties, a

Selection and characterisation of a xylitol-derepressed Aspergillus niger mutant that is apparently impaired in xylitol transport

NARCIS (Netherlands)

Vondervoort, van de P.J.I.; Groot, de M.J.L.; Ruijter, G.J.G.; Visser, J.

2006-01-01

Aspergillus niger is known for its biotechnological applications, such as the use of xylanase enzyme for the degradation of hemicellulose. Depending on culture conditions, several polyols may also be accumulated, such as xylitol during D-xylose oxidation. Also during industrial fermentation of

Selection and production of insoluble xylan hydrolyzing enzyme by ...

African Journals Online (AJOL)

... obtained from 5-day culture at 50°C in the liquid medium using corncob as substrate. ... The optimized concentration of corncob, yeast extract, KH2PO4 and ... The optimal concentration of the active nutrients for xylanase production were 41 ...

Influence of enzymes and ascorbic acid on dough rheology and ...

African Journals Online (AJOL)

The combined action of ascorbic acid and two commercial enzymatic complexes containing amylase and xylanase/amylase was analyzed to determine their effects on dough rheology and bread quality. Seven bread formulations containing different concentrations of these improvers were used in the analysis.

Comparison of aqueous ammonia and dilute acid pretreatment of bamboo fractions: Structure properties and enzymatic hydrolysis.

Science.gov (United States)

Xin, Donglin; Yang, Zhong; Liu, Feng; Xu, Xueru; Zhang, Junhua

2015-01-01

The effect of two pretreatments methods, aqueous ammonia (SAA) and dilute acid (DA), on the chemical compositions, cellulose crystallinity, morphologic change, and enzymatic hydrolysis of bamboo fractions (bamboo yellow, timber, green, and knot) was compared. Bamboo fractions with SAA pretreatment had better hydrolysability than those with DA pretreatment. High crystallinity index resulted in low hydrolysis yield in the conversion of SAA pretreated bamboo fractions, not DA pretreated fractions. The increase of cellulase loading had modestly positive effect in the hydrolysis of both SAA and DA pretreated bamboo fractions, while supplement of xylanase significantly increased the hydrolysis of the pretreated bamboo fractions, especially after SAA pretreatment. The results indicated that SAA pretreatment was more effective than DA pretreatment in conversion of bamboo fractions, and supplementation of xylanase was necessary in effective conversion of the SAA pretreated fractions into fermentable sugars. Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimization of Arundo donax Saccharification by (Hemicellulolytic Enzymes from Pleurotus ostreatus

Directory of Open Access Journals (Sweden)

Rossana Liguori

2015-01-01

Full Text Available An enzymatic mixture of cellulases and xylanases was produced by Pleurotus ostreatus using microcrystalline cellulose as inducer, partially characterized and tested in the statistical analysis of Arundo donax bioconversion. The Plackett-Burman screening design was applied to identify the most significant parameters for the enzymatic hydrolysis of pretreated A. donax. As the most significant influence during the enzymatic hydrolysis of A. donax was exercised by the temperature (°C, pH, and time, the combined effect of these factors in the bioconversion by P. ostreatus cellulase and xylanase was analyzed by a 33 factorial experimental design. It is worth noting that the best result of 480.10 mg of sugars/gds, obtained at 45°C, pH 3.5, and 96 hours of incubation, was significant also when compared with the results previously reached by process optimization with commercial enzymes.

S-protected thiolated hydroxyethyl cellulose (HEC): Novel mucoadhesive excipient with improved stability.

Science.gov (United States)

Leonaviciute, Gintare; Bonengel, Sonja; Mahmood, Arshad; Ahmad Idrees, Muneeb; Bernkop-Schnürch, Andreas

2016-06-25

The aim of this study was the design of novel S-protected thiolated hydroxyethyl cellulose (HEC) and the assessment of its mucoadhesive properties and biodegradability compared to the corresponding unmodified polymer. Thiolated HEC was S-protected via disulfide bond formation between 6-mercaptonicotinamide (6-MNA) and the thiol substructures of the polymer. In vitro screening of mucoadhesive properties was accomplished using two different methods: rotating cylinder studies and viscosity measurements. Moreover, biodegradability of these polymers by cellulase, xylanase and lysozyme was evaluated. MTT and LDH assays were performed on Caco-2 cells to determine the cytotoxicity of S-protected thiolated HEC. Thiolated HEC displayed 280.09±1.70μmol of free thiol groups per gram polymer. S-protected thiolated HEC exhibiting 270.8±21.11μmol immobilized 6-MNA ligands per gram of polymer was shown being 2.4-fold more mucoadhesive compared to thiolated HEC. No mucoadhesion was observed in case of unmodified HEC. Results were in a good agreement with rheological studies. The presence of free thiol moieties likely caused lower degree of hydrolysis by xylanase, whereas the degradation by both enzymes cellulase and xylanase was more hampered when 6-MNA was introduced as ligand for thiol group's protection. Findings in cell viability revealed that all three conjugates were non-toxic. S-protection of thiolated hydroxyethyl cellulose improved mucoadhesive properties and provided pronounced stability towards enzymatic attack, that makes this excipient superior for non-invasive drug administration over thiolated and unmodified forms. Copyright © 2016 Elsevier Ltd. All rights reserved.

Actinomycete enzymes and activities involved in straw saccharification

Energy Technology Data Exchange (ETDEWEB)

McCarthy, A J; Ball, A S [Liverpool Univ. (UK). Dept. of Genetics and Microbiology

1990-01-01

This research programme has been directed towards the analysis of actinomycete enzyme systems involved in the degradation of plant biomass (lignocellulose.) The programme was innovative in that a novel source of enzymes was systematically screened and wheat straw saccharifying activity was the test criterion. Over 200 actinomycete strains representing a broad taxonomic range were screened. A range of specific enzyme activities were involved and included cellulase, xylanase, arabinofuranosidase, acetylesterase, {beta}-xylosidase and {beta}-glucosidase. Since hemicellulose (arabinoxylan) was the primary source of sugar, xylanases were characterized. The xylan-degrading systems of actinomycetes were complex and nonuniform, with up to six separate endoxylanases identified in active strains. Except for microbispora bispora, actinomycetes were found to be a poor source of cellulase activity. Evidence for activity against the lignin fraction of straw was produced for a range of actinomycete strains. While modification reactions were common, cleavage of inter-monomer bonds, and utilization of complex polyphenolic compounds were restricted to two strains: Thermomonospora mesophila and Streptomyces badius. Crude enzyme preparations from actinomycetes can be used to generate sugar, particularly pentoses, directly from cereal straw. The potential for improvements in yield rests with the formulation to cooperative enzyme combinations from different strains. The stability properties of enzymes from thermophilic strains and the general neutral to alkali pH optima offer advantages in certain process situations. Actinomycetes are a particularly rich source of xylanases for commercial application and can rapidly solubilise a lignocarbohydrate fraction of straw which may have both product and pretreatment potential. 31 refs., 4 figs., 5 tabs.

African Journal of Biotechnology - Vol 12, No 8 (2013)

African Journals Online (AJOL)

Production and characterization of thermostable xylanase from Bacillus subtilis XP10 isolated from marine water · EMAIL FREE FULL TEXT EMAIL FREE FULL ... Identification and genetic characterization of phenol-degrading bacterium isolated from oil contaminated · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT

The effect of tannin with and without polyethylene glycol on in vitro ...

African Journals Online (AJOL)

PEG also increased the activity of protease enzymes, xylanase, endo- and exocellulases, indicating that tannins depress the digestibility of feeds partly by suppressing the activity of these enzymes. Consequently, condensed tannin depressed the digestibility of feed in the rumen by affecting the activity of enzymes involved ...

Comparative data on effects of leading pretreatments and enzyme loadings and formulations on sugar

Energy Technology Data Exchange (ETDEWEB)

Wyman, Charles [Univ. of California, Riverside, CA (United States); Balan, Venkatech [Michigan State Univ., East Lansing, MI (United States); Dale, Bruce E. [Michigan State Univ., East Lansing, MI (United States); Elander, Richard [National Renewable Energy Lab. (NREL), Golden, CO (United States); Falls, Matthew [Texas A & M Univ., College Station, TX (United States); Hames, Bonnie [Ceres Corporation, Thousand Oaks, CA (United States); Holtzapple, Mark [Texas A & M Univ., College Station, TX (United States); Ladisch, Michael R. [Purdue Univ., West Lafayette, IN (United States); Lee, Y. Y. [Auburn Univ., AL (United States); Mosier, Nathan [Purdue Univ., West Lafayette, IN (United States); Pallapolu, Venkata R. [Auburn Univ., AL (United States); Shi, Jian [Univ. of California, Riverside, CA (United States); Warner, Ryan E. [Genencor, Palo Alto, CA (United States)

2011-06-16

Dilute sulfuric acid (DA), sulfur dioxide (SO2), liquid hot water (LHW), soaking in aqueous ammonia (SAA), ammonia fiber expansion (AFEX), and lime pretreatments were applied to Alamo, Dacotah, and Shawnee switchgrass. Application of the same analytical methods and material balance approaches facil-itated meaningful comparisons of glucose and xylose yields from combined pretreatment and enzymatic hydrolysis. Use of a common supply of cellulase, beta-glucosidase, and xylanase also eased comparisons. All pretreatments enhanced sugar recovery from pretreatment and subsequent enzymatic hydrolysis substantially compared to untreated switchgrass. Adding beta-glucosidase was effective early in enzy-matic hydrolysis while cellobiose levels were high but had limited effect on longer term yields at the enzyme loadings applied. Adding xylanase improved yields most for higher pH pretreatments where more xylan was left in the solids. Harvest time had more impact on performance than switchgrass variety, and microscopy showed changes in different features could impact performance by different pretreatments.

Optimization of enzymatic extraction of pectin from Opuntia ficus indica cladodes after mucilage removal.

Science.gov (United States)

Bayar, Nadia; Friji, Marwa; Kammoun, Radhouane

2018-02-15

In this study, pectin was isolated from Opuntia ficus indica (OFI) cladodes after removing mucilage using the xylanase and cellulase. The process variables were optimized by the Box Behnken design with three factors at three levels. The optimal extraction condition obtained was: liquid to solid (LS), cellulase to xylanase and enzymes to matter ratios of 22ml/g, 2:1U/U and 4U/g, respectively. The simulated extraction yield of 17.91% was validated by the experimental result (16.67±0.30). The enzyme-extracted pectin from OFI cladodes (EAEPC) was low methylated, with a high uronic acid content, a water and oil holding capacity of 5.42g/g and 1.23g/g, respectively, a good foam and emulsion stability and important DPPH radical scavenging activity. Both the OFI cladodes and enzymatic process present promising alternatives to traditional sources and extraction processes of pectin, respectively. EAEPC thus represents a promising additive in food industries. Copyright © 2017. Published by Elsevier Ltd.

Enzymatic saccharification of biologically pre-treated wheat straw with white-rot fungi.

Science.gov (United States)

Dias, Albino A; Freitas, Gil S; Marques, Guilhermina S M; Sampaio, Ana; Fraga, Irene S; Rodrigues, Miguel A M; Evtuguin, Dmitry V; Bezerra, Rui M F

2010-08-01

Wheat straw was submitted to a pre-treatment by the basidiomycetous fungi Euc-1 and Irpex lacteus, aiming to improve the accessibility of cellulose towards enzymatic hydrolysis via previous selective bio-delignification. This allowed the increase of substrate saccharification nearly four and three times while applying the basidiomycetes Euc-1 and I. lacteus, respectively. The cellulose/lignin ratio increased from 2.7 in the untreated wheat straw to 5.9 and 4.6 after the bio-treatment by the basidiomycetes Euc-1 and I. lacteus, respectively, thus evidencing the highly selective lignin biodegradation. The enzymatic profile of both fungi upon bio-treatment of wheat straw have been assessed including laccase, manganese-dependent peroxidase, lignin peroxidase, carboxymethylcellulase, xylanase, avicelase and feruloyl esterase activities. The difference in efficiency and selectivity of delignification within the two fungi treatments was interpreted in terms of specific lignolytic enzyme profiles and moderate xylanase and cellulolytic activities. (c) 2010 Elsevier Ltd. All rights reserved.

Evaluation of gastrointestinal bacterial population for the production of holocellulose enzymes for biomass deconstruction.

Science.gov (United States)

Asem, Dhaneshwaree; Leo, Vincent Vineeth; Passari, Ajit Kumar; Tonsing, Mary Vanlalhruaii; Joshi, J Beslin; Uthandi, Sivakumar; Hashem, Abeer; Abd Allah, Elsayed Fathi; Singh, Bhim Pratap

2017-01-01

The gastrointestinal (GI) habitat of ruminant and non-ruminant animals sustains a vast ensemble of microbes that are capable of utilizing lignocellulosic plant biomass. In this study, an indigenous swine (Zovawk) and a domesticated goat (Black Bengal) were investigated to isolate bacteria having plant biomass degrading enzymes. After screening and enzymatic quantification of eighty-one obtained bacterial isolates, Serratia rubidaea strain DBT4 and Aneurinibacillus aneurinilyticus strain DBT87 were revealed as the most potent strains, showing both cellulase and xylanase production. A biomass utilization study showed that submerged fermentation (SmF) of D2 (alkaline pretreated pulpy biomass) using strain DBT4 resulted in the most efficient biomass deconstruction with maximum xylanase (11.98 U/mL) and FPase (0.5 U/mL) activities (55°C, pH 8). The present study demonstrated that bacterial strains residing in the gastrointestinal region of non-ruminant swine are a promising source for lignocellulose degrading microorganisms that could be used for biomass conversion.

Evaluation of gastrointestinal bacterial population for the production of holocellulose enzymes for biomass deconstruction.

Directory of Open Access Journals (Sweden)

Dhaneshwaree Asem

Full Text Available The gastrointestinal (GI habitat of ruminant and non-ruminant animals sustains a vast ensemble of microbes that are capable of utilizing lignocellulosic plant biomass. In this study, an indigenous swine (Zovawk and a domesticated goat (Black Bengal were investigated to isolate bacteria having plant biomass degrading enzymes. After screening and enzymatic quantification of eighty-one obtained bacterial isolates, Serratia rubidaea strain DBT4 and Aneurinibacillus aneurinilyticus strain DBT87 were revealed as the most potent strains, showing both cellulase and xylanase production. A biomass utilization study showed that submerged fermentation (SmF of D2 (alkaline pretreated pulpy biomass using strain DBT4 resulted in the most efficient biomass deconstruction with maximum xylanase (11.98 U/mL and FPase (0.5 U/mL activities (55°C, pH 8. The present study demonstrated that bacterial strains residing in the gastrointestinal region of non-ruminant swine are a promising source for lignocellulose degrading microorganisms that could be used for biomass conversion.

Screening for isolation and characterisation of microorganisms and enzymes with usefull potential for degradation of celullose and hemicelluose

Directory of Open Access Journals (Sweden)

José Fernando Mikán Venegas

2004-01-01

Full Text Available A practical, applied microbiology and biotechnology model is presented for isolating and characterising micro-organisms, this being a tiny part of the immense biodiversity of tropical soils. These microbes' ability to produce depolymerases and accessory hydrolases degrading xyloglucans-pectates or glucoarabinoxylans is analysed to evaluate their potential for degrading plant material. We propose culturing micro-organisms on the cell wall as main carbon source and as hydrolitic activity inducer. The same cell walls can be used for cross-linking xylan and for rapid, low cost purification of cellulose and hemicellose degrading enzymes. A 500% xylanase purification yield was obtained in a single step with these affinity supports. Out of the 65 isolates obtained were finally selected for characterising isoenzymes for cellulase and xylanase activities. The five strains are suggested as being potentially useful in different industrial processes regarding degrading cellulose and hemicellulose. Key words: Cellulase, hemicellulase, affinity chromatography, cross-linked substrate, microbiological diversity, composting

Isolation and characterization of aerobic microorganisms with cellulolytic activity in the gut of endogeic earthworms.

Science.gov (United States)

Fujii, Katsuhiko; Ikeda, Kana; Yoshida, Seo

2012-09-01

The ability of earthworms to decompose lignocellulose involves the assistance of microorganisms in their digestive system. While many studies have revealed a diverse microbiota in the earthworm gut, including aerobic and anaerobic microorganisms, it remains unclear which of these species contribute to lignocellulose digestion. In this study, aerobic microorganisms with cellulolytic activity isolated from the gut of two endogeic earthworms, Amynthas heteropoda (Megascolecidae) and Eisenia fetida (Lumbricidae) were isolated by solid culture of gut homogenates using filter paper as a carbon source. A total of 48 strains, including four bacterial and four fungal genera, were isolated from two earthworm species. Characterization of these strains using enzyme assays showed that the most representative ones had exocellulase and xylanase activities, while some had weak laccase activity. These findings suggest that earthworms digest lignocellulose by exploiting microbial exocellulase and xylanase besides their own endocellulase. Phylogenetic analysis showed that among the cellulolytic isolates in both earthworm species Burkholderia and Chaetomium were the dominant bacterial and fungal members.

De novo production of resveratrol from glucose or ethanol by engineered Saccharomyces cerevisiae

DEFF Research Database (Denmark)

Li, Mingji; Kildegaard, Kanchana Rueksomtawin; Chen, Yun

2015-01-01

Resveratrol is a natural antioxidant compound, used as food supplement and cosmetic ingredient. Microbial production of resveratrol has until now been achieved by supplementation of expensive substrates, p-coumaric acid or aromatic amino acids. Here we engineered the yeast Saccharomyces cerevisiae...... to produce resveratrol directly from glucose or ethanol via tyrosine intermediate. First we introduced the biosynthetic pathway, consisting of tyrosine ammonia-lyase from Herpetosiphon aurantiacus, 4-coumaryl-CoA ligase from Arabidopsis thaliana and resveratrol synthase from Vitis vinifera, and obtained 2.......73±0.05 mg L−1 resveratrol from glucose. Then we over-expressed feedback-insensitive alleles of ARO4 encoding 3-deoxy-D-arabino-heptulosonate-7-phosphate and ARO7 encoding chorismate mutase, resulting in production of 4.85±0.31 mg L−1 resveratrol from glucose as the sole carbon source. Next we improved...

Dicty_cDB: Contig-U10229-1 [Dicty_cDB

Lifescience Database Archive (English)

Full Text Available 9_231( CP000909 |pid:none) Chloroflexus aurantiacus J-10-fl... 39 0.54 EU016654_19( EU016654 |pid:none) Uncultured marine mic...405735 ) T7 end of clone AU0AA006A10 of library AU0AA from... 42 6e-18 5 ( CX531734 ) s13dNF81G04MJ024_257410 Methyl Jasmonate-Elic...e-18 5 ( BG585361 ) EST487125 MHAM Medicago truncatula/Glomus versifo... 78 1e-17 3 ( BF649659 ) NF083E04EC1F1033 Elicited cell cultu... 2e-16 2 ( BF650114 ) NF088A08EC1F1055 Elicited cell culture Medicago t... 78 2e-... CP000745 |pid:none) Methanococcus maripaludis C7, c... 151 1e-66 AM114193_1839( AM114193 |pid:none) Uncultured methanogenic

Biological nitrate removal from synthetic wastewater using a fungal ...

African Journals Online (AJOL)

A series of lignocellulosic fungi, capable of cellulase and/or xylanase production, were isolated from soil to be used for cellulose degradation and nitrate removal from nitrate-rich wastewater in simple one-stage anaerobic bioreactors containing grass cuttings as source of cellulose. The fungal consortium, consisting of six ...

Chapter Three

African Journals Online (AJOL)

TonukariJ

Nyerhovwo J. TonukariY, *, John S. Scott-Craig and Jonathan D. Walton. Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824. Accepted 18 November 2002. The expression of four Cochliobolus carbonum endo-1,4-β-xylanase genes (XYL1, XYL2, XYL3, XYL4),.

Protein crystallography with a micrometre-sized synchrotron-radiation beam

International Nuclear Information System (INIS)

Moukhametzianov, Rouslan; Burghammer, Manfred; Edwards, Patricia C.; Petitdemange, Sebastien; Popov, Dimitri; Fransen, Maikel; McMullan, Gregory; Schertler, Gebhard F. X.; Riekel, Christian

2008-01-01

For the first time, protein microcrystallography has been performed with a focused synchrotron-radiation beam of 1 µm using a goniometer with a sub-micrometre sphere of confusion. The crystal structure of xylanase II has been determined with a flux density of about 3 × 10 10 photons s −1 µm −2 at the sample. For the first time, protein microcrystallography has been performed with a focused synchrotron-radiation beam of 1 µm using a goniometer with a sub-micrometre sphere of confusion. The crystal structure of xylanase II has been determined with a flux density of about 3 × 10 10 photons s −1 µm −2 at the sample. Two sets of diffraction images collected from different sized crystals were shown to comprise data of good quality, which allowed a 1.5 Å resolution xylanase II structure to be obtained. The main conclusion of this experiment is that a high-resolution diffraction pattern can be obtained from 20 µm 3 crystal volume, corresponding to about 2 × 10 8 unit cells. Despite the high irradiation dose in this case, it was possible to obtain an excellent high-resolution map and it could be concluded from the individual atomic B-factor patterns that there was no evidence of significant radiation damage. The photoelectron escape from a narrow diffraction channel is a possible reason for reduced radiation damage as indicated by Monte Carlo simulations. These results open many new opportunities in scanning protein microcrystallography and make random data collection from microcrystals a real possibility, therefore enabling structures to be solved from much smaller crystals than previously anticipated as long as the crystallites are well ordered

Silencing of the tomato phosphatidylinositol-phospholipase C2 (SlPLC2) reduces plant susceptibility to Botrytis cinerea

NARCIS (Netherlands)

Gonorazky, Gabriela; Guzzo, María Carla; Abd-El-Haliem, Ahmed M.; Joosten, Matthieu H.A.J.; Laxalt, Ana María

2016-01-01

The tomato [Solanum lycopersicum (Sl)] phosphatidylinositol-phospholipase C (PI-PLC) gene family is composed of six members, named SlPLC1 to SlPLC6, differentially regulated on pathogen attack. We have previously shown that the fungal elicitor xylanase induces a raise of SlPLC2 and SlPLC5

Interaction of water unextractable solids with gluten protein: Effect on dough properties and gluten quality

NARCIS (Netherlands)

Wang, M.; Oudgenoeg, G.; Vliet, T. van; Hamer, R.J.

2003-01-01

In a previous study, we have shown that water unextractable solids (WUS) interfere with gluten formation and affect the quality of the resulting gluten. In this study we aim to explain how WUS can affect the process of gluten formation. To this end, WUS were modified with NaOH, xylanase, horseradish

Performance of West African Dwarf Goats fed maize stover based ...

African Journals Online (AJOL)

The study was carried out to investigate the effect of exogenous fibrolytic enzyme additive (containing cellulase, xylanase and beta glucanase) on the growth performance and nutrient digestibility parameters of West African dwarf (WAD) goats fed total mixed ration in the dry season. A total of sixteen (16) WAD goats were ...

African Journal of Biotechnology - Vol 15, No 20 (2016)

African Journals Online (AJOL)

The use of Amazon fungus (Trametes sp.) in the production of cellulase and xylanase · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Salony Aquino Pereira, Rafael Lopes e Oliveira, Sergio Duvoisin Jr, Leonor Alves de Oliveira da Silva, Patrícia Melchionna ...

Interaction of water unextractable solids with gluten protein: effect on dough properties and gluten quality

NARCIS (Netherlands)

Wang, M.; Oudgenoeg, G.; Vliet, van T.; Hamer, R.J.

2003-01-01

Abstract In a previous study, we have shown that water unextractable solids (WUS) interfere with gluten formation and affect the quality of the resulting gluten. In this study we aim to explain how WUS can affect the process of gluten formation. To this end, WUS were modified with NaOH, xylanase,

1740-IJBCS-Article -Mohammed I. Jaaforu

African Journals Online (AJOL)

hp

2Microbial Physiology and Biotechnology Research Group, Department of Botany and Microbiology, ... Trichoderma viride Fd18 produced 10.4 U/ml of xylanase using NH4Cl as nitrogen source, while NH4NO3 repressed enzyme production by Aspergillus ustus Fb2. The fungal ... characteristics according to Barnett (1960),.

Author Details - African Journals Online

African Journals Online (AJOL)

Effects of salt and water stress on plant biomass and photosynthetic characteristics of Tamarisk (Tamarix chinensis Lour.) seedlings. Abstract PDF · Vol 11, No 15 (2012) - Articles Production and some properties of the thermostable feruloyl esterase and xylanase from Bacillus pumilus. Abstract PDF · Vol 11, No 26 (2012) - ...

Theoretical Simulations and Ultrafast Pump-probe Spectroscopy Experiments in Pigment-protein Photosynthetic Complexes

Energy Technology Data Exchange (ETDEWEB)

Buck, D. R. [Iowa State Univ., Ames, IA (United States)

2000-09-12

Theoretical simulations and ultrafast pump-probe laser spectroscopy experiments were used to study photosynthetic pigment-protein complexes and antennae found in green sulfur bacteria such as Prosthecochloris aestuarii, Chloroflexus aurantiacus, and Chlorobium tepidum. The work focused on understanding structure-function relationships in energy transfer processes in these complexes through experiments and trying to model that data as we tested our theoretical assumptions with calculations. Theoretical exciton calculations on tubular pigment aggregates yield electronic absorption spectra that are superimpositions of linear J-aggregate spectra. The electronic spectroscopy of BChl c/d/e antennae in light harvesting chlorosomes from Chloroflexus aurantiacus differs considerably from J-aggregate spectra. Strong symmetry breaking is needed if we hope to simulate the absorption spectra of the BChl c antenna. The theory for simulating absorption difference spectra in strongly coupled photosynthetic antenna is described, first for a relatively simple heterodimer, then for the general N-pigment system. The theory is applied to the Fenna-Matthews-Olson (FMO) BChl a protein trimers from Prosthecochloris aestuarii and then compared with experimental low-temperature absorption difference spectra of FMO trimers from Chlorobium tepidum. Circular dichroism spectra of the FMO trimer are unusually sensitive to diagonal energy disorder. Substantial differences occur between CD spectra in exciton simulations performed with and without realistic inhomogeneous distribution functions for the input pigment diagonal energies. Anisotropic absorption difference spectroscopy measurements are less consistent with 21-pigment trimer simulations than 7-pigment monomer simulations which assume that the laser-prepared states are localized within a subunit of the trimer. Experimental anisotropies from real samples likely arise from statistical averaging over states with diagonal energies shifted by

Trichoderma reesei CE16 acetyl esterase and its role in enzymatic degradation of acetylated hemicellulose

DEFF Research Database (Denmark)

Biely, Peter; Cziszarava, Maria; Agger, Jane W.

2014-01-01

Results The combined action of GH10 xylanase and acetylxylan esterases (AcXEs) leads to formation of neutral and acidic xylooligosaccharides with a few resistant acetyl groups mainly at their non-reducing ends. We show here that these acetyl groups serve as targets for TrCE16 AcE. The most promin...

Purification and characterization of xylanase from Aspergillus ...

African Journals Online (AJOL)

MIET

2013-05-15

May 15, 2013 ... INTRODUCTION. Xylan, the major hemicellulose component in a plant cell ... enzyme treatment is the availability and cost of the enzyme. About 30 ... be achieved using solid agricultural waste materials as substrates (Wizani ...

Production and characterization of thermostable xylanase from ...

African Journals Online (AJOL)

ajl2

2013-02-20

Feb 20, 2013 ... Penicillium, .... production in liquid medium ranged from 0.11 to 0.21. U/ml (data not shown). ... Lane 2 represents the negative control (Bacillus sp.). Lane 3 is .... circulans D1 in submerged fermentation using response surface.

Engineering thermostable xylanase enzyme mutant from Bacillus ...

African Journals Online (AJOL)

user

2010-11-22

Nov 22, 2010 ... waste treatment, fuel and chemical production, paper and pulp industries; but these applications ... approaches have been taken: screening organisms from various ... and site-directed mutagenesis was applied on this.

Photosynthetic antennae systems: energy transport and optical absorption

International Nuclear Information System (INIS)

Reineker, P.; Supritz, Ch.; Warns, Ch.; Barvik, I.

2004-01-01

The energy transport and the optical line shape of molecular aggregates, modeling bacteria photosynthetic light-harvesting systems (chlorosomes in the case of Chlorobium tepidum or Chloroflexus aurantiacus and LH2 in the case of Rhodopseudomonas acidophila) is investigated theoretically. The molecular units are described by two-level systems with an average excitation energy ε and interacting with each other through nearest-neighbor interactions. For LH2 an elliptical deformation of the ring is also allowed. Furthermore, dynamic and in the case of LH2 also quasi-static fluctuations of the local excitation energies are taken into account, simulating fast molecular vibrations and slow motions of the protein backbone, respectively. The fluctuations are described by Gaussian Markov processes in the case of the chlorosomes and by colored dichotomic Markov processes, with exponentially decaying correlation functions, with small (λ s ) and large (λ) decay constants, in the case of LH2

Identification of Pectin Degrading Enzymes Secreted by Xanthomonas oryzae pv. oryzae and Determination of Their Role in Virulence on Rice.

Directory of Open Access Journals (Sweden)

Lavanya Tayi

Full Text Available Xanthomonas oryzae pv.oryzae (Xoo causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we have identified some of the pectin degrading enzymes of Xoo and assessed their role in virulence. Bioinformatics analysis indicated the presence of four pectin homogalacturonan (HG degrading genes in the genome of Xoo. The four HG degrading genes include one polygalacturonase (pglA, one pectin methyl esterase (pmt and two pectate lyases (pel and pelL. There was no difference in the expression of pglA, pmt and pel genes by laboratory wild type Xoo strain (BXO43 grown in either nutrient rich PS medium or in plant mimic XOM2 medium whereas the expression of pelL gene was induced in XOM2 medium as indicated by qRT-PCR experiments. Gene disruption mutations were generated in each of these four genes. The polygalacturonase mutant pglA- was completely deficient in degrading the substrate Na-polygalacturonicacid (PGA. Strains carrying mutations in the pmt, pel and pelL genes were as efficient as wild type Xoo (BXO43 in cleaving PGA. These observations clearly indicate that PglA is the major pectin degrading enzyme produced by Xoo. The pectin methyl esterase, Pmt, is the pectin de-esterifying enzyme secreted by Xoo as evident from the enzymatic activity assay performed using pectin as the substrate. Mutations in the pglA, pmt, pel and pelL genes have minimal effects on virulence. This suggests that, as compared to cellulases and xylanases, the HG degrading enzymes may not have a major role in the pathogenicity of Xoo.

Sequence homolog-based molecular engineering for shifting the enzymatic pH optimum

Directory of Open Access Journals (Sweden)

Fuqiang Ma

2016-09-01

Full Text Available Cell-free synthetic biology system organizes multiple enzymes (parts from different sources to implement unnatural catalytic functions. Highly adaption between the catalytic parts is crucial for building up efficient artificial biosynthetic systems. Protein engineering is a powerful technology to tailor various enzymatic properties including catalytic efficiency, substrate specificity, temperature adaptation and even achieve new catalytic functions. However, altering enzymatic pH optimum still remains a challenging task. In this study, we proposed a novel sequence homolog-based protein engineering strategy for shifting the enzymatic pH optimum based on statistical analyses of sequence-function relationship data of enzyme family. By two statistical procedures, artificial neural networks (ANNs and least absolute shrinkage and selection operator (Lasso, five amino acids in GH11 xylanase family were identified to be related to the evolution of enzymatic pH optimum. Site-directed mutagenesis of a thermophilic xylanase from Caldicellulosiruptor bescii revealed that four out of five mutations could alter the enzymatic pH optima toward acidic condition without compromising the catalytic activity and thermostability. Combination of the positive mutants resulted in the best mutant M31 that decreased its pH optimum for 1.5 units and showed increased catalytic activity at pH < 5.0 compared to the wild-type enzyme. Structure analysis revealed that all the mutations are distant from the active center, which may be difficult to be identified by conventional rational design strategy. Interestingly, the four mutation sites are clustered at a certain region of the enzyme, suggesting a potential “hot zone” for regulating the pH optima of xylanases. This study provides an efficient method of modulating enzymatic pH optima based on statistical sequence analyses, which can facilitate the design and optimization of suitable catalytic parts for the construction

Identification of Pectin Degrading Enzymes Secreted by Xanthomonas oryzae pv. oryzae and Determination of Their Role in Virulence on Rice.

Science.gov (United States)

Tayi, Lavanya; Maku, Roshan V; Patel, Hitendra Kumar; Sonti, Ramesh V

2016-01-01

Xanthomonas oryzae pv.oryzae (Xoo) causes the serious bacterial blight disease of rice. Xoo secretes a repertoire of plant cell wall degrading enzymes (CWDEs) like cellulases, xylanases, esterases etc., which act on various components of the rice cell wall. The major cellulases and xylanases secreted by Xoo have been identified and their role in virulence has been determined. In this study, we have identified some of the pectin degrading enzymes of Xoo and assessed their role in virulence. Bioinformatics analysis indicated the presence of four pectin homogalacturonan (HG) degrading genes in the genome of Xoo. The four HG degrading genes include one polygalacturonase (pglA), one pectin methyl esterase (pmt) and two pectate lyases (pel and pelL). There was no difference in the expression of pglA, pmt and pel genes by laboratory wild type Xoo strain (BXO43) grown in either nutrient rich PS medium or in plant mimic XOM2 medium whereas the expression of pelL gene was induced in XOM2 medium as indicated by qRT-PCR experiments. Gene disruption mutations were generated in each of these four genes. The polygalacturonase mutant pglA- was completely deficient in degrading the substrate Na-polygalacturonicacid (PGA). Strains carrying mutations in the pmt, pel and pelL genes were as efficient as wild type Xoo (BXO43) in cleaving PGA. These observations clearly indicate that PglA is the major pectin degrading enzyme produced by Xoo. The pectin methyl esterase, Pmt, is the pectin de-esterifying enzyme secreted by Xoo as evident from the enzymatic activity assay performed using pectin as the substrate. Mutations in the pglA, pmt, pel and pelL genes have minimal effects on virulence. This suggests that, as compared to cellulases and xylanases, the HG degrading enzymes may not have a major role in the pathogenicity of Xoo.

Purification and biochemical properties of a new thermostable ...

African Journals Online (AJOL)

The enzyme was stable for a long time-period up to 50°C and for 1 h at 60°C. Although the xylanase had a lower carboxymethylcellulase activity, it lacked activity towards substituted xylan, xylobiose, inulin, starch, polygalacturonic acid or pNP glycosides. Kinetic parameters indicated higher efficiency in the hydrolysis of ...

Facilitating the enzymatic saccharification of pulped bamboo residues by degrading the remained xylan and lignin-carbohydrates complexes.

Science.gov (United States)

Huang, Caoxing; He, Juan; Li, Xin; Min, Douyong; Yong, Qiang

2015-09-01

Kraft pulping was performed on bamboo residues and its impact on the chemical compositions and the enzymatic digestibility of the samples were investigated. To improve the digestibility of sample by degrading the xylan and lignin-carbohydrates complexes (LCCs), xylanase and α-L-arabinofuranosidase (AF) were supplemented with cellulase. The results showed more carbohydrates were remained in the samples pulped with low effective alkali (EA) charge, compared to conventional kraft pulping. When 120 IU/g xylanase and 15 IU/g AF were supplemented with 20 FPU/g cellulase, the xylan degradation yield of the sample pulped with 12% EA charge increased from 68.20% to 88.35%, resulting in an increased enzymatic saccharification efficiency from 58.98% to 83.23%. The amount of LCCs in this sample decreased from 8.63/100C9 to 2.99/100C9 after saccharification with these enzymes. The results indicated that degrading the remained xylan and LCCs in the pulp could improve its enzymatic digestibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of Maize Source and Complex Enzymes on Performance and Nutrient Utilization of Broilers

Directory of Open Access Journals (Sweden)

Defu Tang

2014-12-01

Full Text Available The objective of this study was to investigate the effect of maize source and complex enzymes containing amylase, xylanase and protease on performance and nutrient utilization of broilers. The experiment was a 4×3 factorial design with diets containing four source maize samples (M1, M2, M3, and M4 and without or with two kinds of complex enzyme A (Axtra XAP and B (Avizyme 1502. Nine hundred and sixty day old Arbor Acres broiler chicks were used in the trial (12 treatments with 8 replicate pens of 10 chicks. Birds fed M1 diet had better body weight gain (BWG and lower feed/gain ratio compared with those fed M3 diet and M4 diet (p0.05, respectively. The fresh feces output was significantly decreased by the addition of enzyme B (p<0.05. Maize source affects the nutrients digestibility and performance of broilers, and a combination of amylase, xylanase and protease is effective in improving the growth profiles of broilers fed maize-soybean-rapeseed-cotton mixed diets.

Use of a new Trichoderma harzianum strain isolated from the Amazon rainforest with pretreated sugar cane bagasse for on-site cellulase production.

Science.gov (United States)

Delabona, Priscila da Silva; Farinas, Cristiane Sanchez; da Silva, Mateus Ribeiro; Azzoni, Sindelia Freitas; Pradella, José Geraldo da Cruz

2012-03-01

The on-site production of cellulases is an important strategy for the development of sustainable second-generation ethanol production processes. This study concerns the use of a specific cellulolytic enzyme complex for hydrolysis of pretreated sugar cane bagasse. Glycosyl hydrolases (FPase, xylanase, and β-glucosidase) were produced using a new strain of Trichoderma harzianum, isolated from the Amazon rainforest and cultivated under different conditions. The influence of the carbon source was first investigated using shake-flask cultures. Selected carbon sources were then further studied under different pH conditions using a stirred tank bioreactor. Enzymatic activities up to 121 FPU/g, 8000 IU/g, and 1730 IU/g of delignified steam-exploded bagasse+sucrose were achieved for cellulase, xylanase and β-glucosidase, respectively. This enzymatic complex was used to hydrolyze pretreated sugar cane bagasse. A comparative evaluation, using an enzymatic extract from Trichoderma reesei RUTC30, indicated similar performance of the T. harzianum enzyme complex, being a potential candidate for on-site production of enzymes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Assessment of the Brazilian potential for the production of enzymes for biofuels from agroindustrial materials

Energy Technology Data Exchange (ETDEWEB)

Machado de Castro, Silvia [Federal University of Rio de Janeiro, Environmental Engineering Program, Rio de Janeiro (Brazil); Machado de Castro, Aline [PETROBRAS, Biotechnology Division, Research and Development Center, Rio de Janeiro (Brazil)

2012-03-15

Brazil is one of the largest bioethanol and biodiesel producers in the world. Its biodiversity and environmental characteristics create the opportunity to make Brazil a major producer of biotechnological products, such as enzymes for the bioenergy industry. This review gives a brief status of the production of amylases, cellulases, xylanases, and lipases and their application on the synthesis of bioethanol and biodiesel. The historical utilization of several agroindustrial by-products as feedstocks in such processes are presented, as well as the Brazilian market for these enzymes. Finally, an innovative and multidisciplinary approach based on geographic information systems is used in a case study for the estimation of the potential production of the biocatalysts in Brazil. Results indicate that the national production of concentrated preparations based on amylases, cellulases, lipases, and xylanases could reach 3.1 x 10{sup 7}, 3.2 x 10{sup 7}, 3.1 x 10{sup 8}, and 2.9 x 10{sup 9} t, respectively. Therefore, Brazil presents a huge potential for the production of biocatalysts from renewable materials. (orig.)

Isolation and Screening of Potential Cellulolytic and Xylanolytic Bacteria from Soil Sample for Degradation of Lignocellulosic Biomass

Directory of Open Access Journals (Sweden)

Bhupal Govinda Shrestha

2016-11-01

them with the aptitude to produce stable enzymes, little emphasis has been given to cellulose/xylanase production from bacteria. Seven soil samples were collected from eastern hilly districts of Nepal viz. Taplejung, Panchthar and Sankhuwasabha districts, from soil surface and at depth of 10cm to 20cm, and were isolated separately. From the seven soil samples, four bacterial isolates were obtained. Isolates (PSS, P1D, TLC, SNK were then screened for cellulolytic/xylanolytic activity using Congo red assay on Carboxymethylcellulose (CMC/xylan agar plates. The enzyme activity obtained from isolates was dependent on substrate concentration. The activity of enzymes produced by isolates were also measured and compared on pretreated sugarcane bagasse. Among those samples, the greatest zone of inhibition in both CMC (1.3 cm and xylan (1.0 cm agar media was seen in isolate P1D. It also produced the highest activity of endoglucanase and xylanase i.e. activity 0.035 U/mL and 0.050 U/mL respectively at 0.010 mg mL-1 standard substrate concentration of CMC and xylan.

Characterization of cellulolytic enzymes and bioH2 production from anaerobic thermophilic Clostridium sp. TCW1.

Science.gov (United States)

Lo, Yung-Chung; Huang, Chi-Yu; Cheng, Chieh-Lun; Lin, Chiu-Yue; Chang, Jo-Shu

2011-09-01

A thermophilic anaerobic bacterium Clostridium sp. TCW1 was isolated from dairy cow dung and was used to produce hydrogen from cellulosic feedstock. Extracellular cellulolytic enzymes produced from TCW1 strain were identified as endoglucanases (45, 53 and 70 kDa), exoglucanase (70 kDa), xylanases (53 and 60 kDa), and β-glucosidase (45 kDa). The endoglucanase and xylanase were more abundant. The optimal conditions for H2 production and enzyme production of the TCW1 strain were the same (60 °C, initial pH 7, agitation rate of 200 rpm). Ten cellulosic feedstock, including pure or natural cellulosic materials, were used as feedstock for hydrogen production by Clostridium strain TCW1 under optimal culture conditions. Using filter paper at 5.0 g/L resulted in the most effective hydrogen production performance, achieving a H2 production rate and yield of 57.7 ml/h/L and 2.03 mol H2/mol hexose, respectively. Production of cellulolytic enzyme activities was positively correlated with the efficiency of dark-H2 fermentation. Copyright © 2011 Elsevier Ltd. All rights reserved.

Purification, crystallization and preliminary X-ray analysis of a thermostable glycoside hydrolase family 43 β-xylosidase from Geobacillus thermoleovorans IT-08

International Nuclear Information System (INIS)

Rohman, Ali; Oosterwijk, Niels van; Kralj, Slavko; Dijkhuizen, Lubbert; Dijkstra, Bauke W.; Puspaningsih, Ni Nyoman Tri

2007-01-01

The β-xylosidase was crystallized using PEG 6000 as precipitant. 5% PEG 6000 yielded bipyramid-shaped tetragonal crystals diffracting to 1.55 Å resolution, and 13% PEG 6000 gave rectangular monoclinic crystals diffracting to 1.80 Å resolution. The main enzymes involved in xylan-backbone hydrolysis are endo-1,4-β-xylanase and β-xylosidase. β-Xylosidase converts the xylo-oligosaccharides produced by endo-1,4-β-xylanase into xylose monomers. The β-xylosidase from the thermophilic Geobacillus thermoleovorans IT-08, a member of glycoside hydrolase family 43, was crystallized at room temperature using the hanging-drop vapour-diffusion method. Two crystal forms were observed. Bipyramid-shaped crystals belonging to space group P4 3 2 1 2, with unit-cell parameters a = b = 62.53, c = 277.4 Å diffracted to 1.55 Å resolution. The rectangular crystals belonged to space group P2 1 , with unit-cell parameters a = 57.94, b = 142.1, c = 153.9 Å, β = 90.5°, and diffracted to 1.80 Å resolution

Visualization of enzyme activities inside earthworm pores

Science.gov (United States)

Hoang, Duyen; Razavi, Bahar S.

2015-04-01

In extremely dynamic microhabitats as bio-pores made by earthworm, the in situ enzyme activities are assumed as a footprint of complex biotic interactions. Our study focused on the effect of earthworm on the enzyme activities inside bio-pores and visualizing the differences between bio-pores and earthworm-free soil by zymography technique (Spohn and Kuzyakov, 2013). For the first time, we aimed at quantitative imaging of enzyme activities in bio-pores. Lumbricus terrestris L. was placed into transparent box (15×20×15cm). After two weeks when bio-pore systems were formed by earthworms, we visualized in situ enzyme activities of five hydrolytic enzymes (β-glucosidase, cellobiohydrolase, chitinase, xylanase, leucine-aminopeptidase, and phosphatase. Zymography showed higher activity of β-glucosidase, chitinase, xylanase and phosphatase in biopores comparing to bulk soil. However, the differences in activity of cellobiohydrolase and leucine aminopeptidase between bio-pore and bulk soil were less pronounced. This demonstrated an applicability of zymography approach to monitor and to distinguish the in situ activity of hydrolytic enzymes in soil biopores.

Cellulolytic enzymes, nucleic acids encoding them and methods for making and using them

Science.gov (United States)

Gray, Kevin A [San Diego, CA; Zhao, Lishan [Emeryville, CA; Cayouette, Michelle H [San Diego, CA

2012-01-24

The invention provides polypeptides having any cellulolytic activity, e.g., a cellulase activity, a endoglucanase, a cellobiohydrolase, a beta-glucosidase, a xylanase, a mannanse, a .beta.-xylosidase, an arabinofuranosidase, and/or an oligomerase activity, polynucleotides encoding these polypeptides, and methods of making and using these polynucleotides and polypeptides. In one aspect, the invention is directed to polypeptides having any cellulolytic activity, e.g., a cellulase activity, e.g., endoglucanase, cellobiohydrolase, beta-glucosidase, xylanase, mannanse, .beta.-xylosidase, arabinofuranosidase, and/or oligomerase activity, including thermostable and thermotolerant activity, and polynucleotides encoding these enzymes, and making and using these polynucleotides and polypeptides. In one aspect, the invention provides polypeptides having an oligomerase activity, e.g., enzymes that convert recalcitrant soluble oligomers to fermentable sugars in the saccharification of biomass. The polypeptides of the invention can be used in a variety of pharmaceutical, agricultural, food and feed processing and industrial contexts. The invention also provides compositions or products of manufacture comprising mixtures of enzymes comprising at least one enzyme of this invention.

[Biodiversity and enzymes of culturable facultative-alkaliphilic actinobacteria in saline-alkaline soil in Fukang, Xinjiang].

Science.gov (United States)

Zhang, Yongguang; Liu, Qing; Wang, Hongfei; Zhang, Daofeng; Chen, Jiyue; Zhang, Yuanming; Li, Wenjun

2014-02-04

In order to analyze the biodiversity of cultivable facultative-alkaliphilic actinobacteria and the enzymes they produced. Total 10 soil samples were collected from saline-alkaline environments of Fukang, Xinjiang province. Facultative-alkaliphilic actinobacteria strains were isolated and identified by 16S rRNA gene sequence analysis. Enzymes including amylase, proteinase, xylanase, and cellulase were detected. Total 116 facultative-alkaliphilic actinobacterial strains and 4 alkali-tolerant actinobacterial strains were isolated from the samples, and those strains were distributed within 22 genera in 13 families and 8 orders of actinobacteria based on their 16S rRNA gene sequence analysis. The ratio of non-predominant Streptomyces and Nocardiopsis strains were 53.3%. The positive rates of amylase, proteinase, xylanase and cellulase were 35.8, 37.6, 28.3 and 17.5%, respectively. Diverse facultative-alkaliphilic actinobacteria were discovered from saline-alkaline environments of Fukang. Facultative-alkaliphilic actinobacteria are a potential source for enzymes. The study would facilitate the knowledge of the diversity of facultative-alkaliphilic actinobacteria, and provide the technical basis for exploration of facultative-alkaliphilic actinobacteria resources.

Comparative evaluation of lignocellulolytic activities of filamentous cultures of monocentric and polycentric anaerobic fungi.

Science.gov (United States)

Dagar, Sumit Singh; Kumar, Sanjay; Mudgil, Priti; Puniya, Anil Kumar

2018-04-01

Sixteen strains of monocentric and polycentric anaerobic fungi were evaluated for cellulase, xylanase and esterase activities. Though strain level variations were observed among all genera, Neocallimastix and Orpinomyces strains exhibited the highest lignocellulolytic activities. The esterase activities of monocentric group of anaerobic fungi were better than the polycentric group. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of wheat cultivar and enzyme addition to broiler chicken diets on nutrient digestibility, performance, and apparent metabolizable energy content.

NARCIS (Netherlands)

Gutierrez del Alamo Oms, A.; Verstegen, M.W.A.; Hartog, den L.A.; Villamide, M.J.

2008-01-01

A total of 5,000 one-day-old male broiler chickens were assigned to 8 different treatments in a 4 x 2 factorial design. Four wheat cultivars (Amiro, Guadalupe, Isengrain, and Horzal) and 2 levels (0 or 1 kg/t of feed) of an enzyme cocktail (Avizyme 1300, xylanase, 2,500 U/kg and protease, 800 U/kg)

Enhanced production of 3-hydroxypropionic acid from glucose via malonyl-CoA pathway by engineered Escherichia coli.

Science.gov (United States)

Cheng, Zhuan; Jiang, Jiaqi; Wu, Hui; Li, Zhimin; Ye, Qin

2016-01-01

In this study, production of 3-HP via malonyl-CoA was investigated by using metabolically engineered Escherichia coli carrying heterogeneous acetyl-CoA carboxylase (Acc) from Corynebacterium glutamicum and codon-optimized malonyl-CoA reductase (MCR) from Chloroflexus aurantiacus. Three engineered E. coli strains with different host-vector systems were constructed and investigated. The results indicated that the combination of E. coli BL21(DE3) and pET28a was the most efficient host-vector system for 3-HP production, and the highest concentration of 3-HP attained in shake flask cultivation reached 1.80g/L by the strain BE-MDA with induction at 0.25mM IPTG and 25°C, and supplementation of NaHCO3 and biotin. In fed-batch fermentation performed in a 5-L reactor, the concentration of 3-HP achieved 10.08g/L in 36h. Copyright © 2015 Elsevier Ltd. All rights reserved.

A proteomics-based study of endogenous and microbial xylanases and xylanase inhibitors associated with barley grains used for liquid feed

DEFF Research Database (Denmark)

Sultan, Abida

the surface-associated proteins (surfome) constitutively present on barley grains of two barley cultivars were established using 2 -DE and mass spectrometry. The majority of the identified proteins was of plant origin and ascribed to play a role in defense and/or oxidative stress mechanisms. A metaproteomics....../influence the plant and/or competitors via secretion of an array of enzymes and compounds/metabolites. The occurrence of these enzyme activities both of plant and fungal origin present a great potential for improvement of grain nutritional components for feed applications. Knowledge is lacking in the variation...

Influencia de la concentración de inóculo en la producción de celulasa y xilanasa por Aspergillus niger

Directory of Open Access Journals (Sweden)

Myriam L. Izarra

2010-07-01

Full Text Available Título en inglés: Influence of inoculum concentration on the cellulase and xylanase production by Aspergillus niger Resumen Existe un gran interés por el uso de enzimas lignocelulolíticas en varias industrias, y en la biodegradación de biomasa para la producción de biocombustibles y otras aplicaciones. Entre las fuentes microbianas de enzimas, Aspergillus niger es uno de los microorganismos más utilizados en la producción de enzimas industriales, debido a sus niveles altos de secreción de proteína y a su condición GRAS (generally regarded as safe. El objetivo del presente estudio fue evaluar la influencia de la concentración de inóculo en la morfología y producción de celulasas y xilanasas con A. niger en cultivo sumergido. Para ello, fueron inoculados matraces de 250 mL con 40 mL de medio con 3% (v/v de una suspensión de 104 o 108 esporas por mililitro e incubados a 28 ºC y 175 rpm durante 120 horas. Se utilizaron 10 g*L-1 de lactosa como fuente de carbono. En cada caso se determinó la cantidad de biomasa, la proteína extracelular soluble, lactosa residual, actividad celulasa total y xilanasa cada 24 horas. Aunque no hubo un efecto notorio en la morfología de crecimiento, salvo en el color y el diámetro de pellets obtenidos, sí se afectó la µmax (0,06 y 0,03 h-1 para 104 y 108 esporas*mL-1, respectivamente y la concentración máxima de biomasa. Además, mientras que las productividades volumétricas de celulasa (ΓFPA (8,2 y 8,0 UI.*L-1*h-1 para 104 y 108 esporas*mL-1, respectivamente fueron similares para ambos inóculos, la productividad de xilanasa (ΓXIL fue mayor para el inóculo más concentrado (29,7 y 33,4 UI¨*L-1*h-1 para 104 y 108 esporas*mL-1, respectivamente. Los resultados indican que la productividad de celulasas y xilanasas está estrechamente relacionada con la concentración de inóculo. Palabras clave: celulasa; xilanasa; cultivo sumergido; morfología; Aspergillus niger. Abstract There is a great

Efeito da fitase e xilanase sobre o desempenho e as características ósseas de frangos de corte alimentados com dietas contendo farelo de arroz Effect of phytase and xilanase on the performance and bone characteristics of broiler chicks fed diets with rice bran

Directory of Open Access Journals (Sweden)

Ademir José Conte

2003-10-01

Full Text Available O presente trabalho foi conduzido com o objetivo de verificar o efeito do uso da fitase e xilanase no desempenho e na deposição óssea de minerais em frangos de corte alimentados com dietas contendo 15% de farelo de arroz, baixo fósforo disponível e sem suplementação de ferro, cobre, zinco e manganês. A fitase utilizada foi da marca comercial Natuphos 5000 e a xilanase, da marca Avizyme 1300. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 4x2+1. A dieta controle foi composta por níveis adequados de nutrientes, sem farelo de arroz e sem enzimas. As dietas dos demais tratamentos foram formuladas com 15% de farelo de arroz, contendo baixo fósforo disponível (40% do recomendado e sem suplementação inorgânica de Fe, Cu, Zn e Mn, com quatro níveis de fitase (0, 400, 800 e 1.200 FTU/kg, com ou sem xilanase (1 kg/t. As variáveis estudadas aos 21 e 42 dias de idade foram desempenho e cinzas, P, Zn, Fe, Mn e Cu na tíbia. O peso vivo e consumo de ração aumentaram de maneira significativa com a adição de fitase, enquanto que a conversão alimentar não foi afetada, tanto aos 21 como aos 42 dias. O melhor nível de fitase foi de 1.105 e 1.023 FTU/kg para melhor desempenho, aos 21 e 42 dias de idade, respectivamente. A xilanase não afetou significativamente o peso vivo e o consumo de ração, porém melhorou significativamente a conversão alimentar nas duas idades avaliadas, em função de menor consumo de ração nas aves que receberam xilanase. Os níveis de fitase promoveram aumento linear nos teores de cinzas e fósforo da tíbia e não afetaram a deposição de Zn, Fe, Mn e Cu, nas duas idades estudadas. A xilanase não afetou os parâmetros avaliados na tíbia.The present work was designed to verify the effect of the use of phytase and xylanase upon the performance and bone deposition of minerals in broiler diets containing 15% of rice bran, low available phosphorus and without supplementation of iron

Agricultural waste from the tequila industry as substrate for the production of commercially important enzymes.

Science.gov (United States)

Huitron, C; Perez, R; Sanchez, A E; Lappe, P; Rocha Zavaleta, L

2008-01-01

Approximately 1 million tons of Agave tequilana plants are processed annually by the Mexican Tequila industry generating vast amounts of agricultural waste. The aim of this study was to investigate the potential use of Agave tequilana waste as substrate for the production of commercially important enzymes. Two strains of Aspergillus niger (CH-A-2010 and CH-A-2016), isolated from agave fields, were found to grow and propagate in submerged cultures using Agave tequilana waste as substrate. Isolates showed simultaneous extracellular inulinase, xylanase, pectinase, and cellulase activities. Aspergillus CH-A-2010 showed the highest production of inulinase activity (1.48 U/ml), whereas Aspergillus niger CH-A-2016 produced the highest xylanase (1.52 U/ml) and endo-pectinase (2.7U/ml) activities. In both cases production of enzyme activities was significantly higher on Agave tequilana waste than that observed on lemon peel and specific polymeric carbohydrates. Enzymatic hydrolysis of raw A. tequilana stems and leaves, by enzymes secreted by the isolates yielded maximum concentrations of reducing sugars of 28.2 g/l, and 9.9 g/l respectively. In conclusion, Agave tequilana waste can be utilized as substrate for the production of important biotechnological enzymes.

Effects of Enzyme Complex Supplementation to a Paddy-based Diet on Performance and Nutrient Digestibility of Meat-type Ducks

Directory of Open Access Journals (Sweden)

P. Kang

2013-02-01

Full Text Available Paddy rice is rarely used as a feed because of its high fiber content. In this study, two experiments were conducted to study the effects of supplementing an enzyme complex consisting of xylanase, beta-glucanase and cellulase, to paddy-based diets on the performance and nutrient digestibility in meat-type ducks. In the both experiments, meat-type ducks (Cherry Valley were randomly assigned to four treatments. Treatment 1 was a basal diet of corn-soybean; treatment 2 was a basal diet of corn-paddy-soybean; treatment 3, had enzyme complex added to the corn-paddy-soybean basal diet at levels of 0.5 g/kg diet; and treatment 4, had enzyme complex added to the corn-paddy-soybean diet at levels of 1.0 g/kg diet. The results showed that the enzyme complex increased the ADG, and decreased the ADFI and F/G significantly (p0.05. The outcome of this research indicates that the application of enzyme complex made up of xylanase, beta-glucanase, and cellulase, in the corn-paddy-soybean diet, can improve performance and nutrition digestibility in meat-type ducks.

High-solids enrichment of thermophilic microbial communities and their enzymes on bioenergy feedstocks

Energy Technology Data Exchange (ETDEWEB)

Reddy, A. P.; Allgaier, M.; Singer, S.W.; Hazen, T.C.; Simmons, B.A.; Hugenholtz, P.; VanderGheynst, J.S.

2011-04-01

Thermophilic microbial communities that are active in a high-solids environment offer great potential for the discovery of industrially relevant enzymes that efficiently deconstruct bioenergy feedstocks. In this study, finished green waste compost was used as an inoculum source to enrich microbial communities and associated enzymes that hydrolyze cellulose and hemicellulose during thermophilic high-solids fermentation of the bioenergy feedstocks switchgrass and corn stover. Methods involving the disruption of enzyme and plant cell wall polysaccharide interactions were developed to recover xylanase and endoglucanase activity from deconstructed solids. Xylanase and endoglucanase activity increased by more than a factor of 5, upon four successive enrichments on switchgrass. Overall, the changes for switchgrass were more pronounced than for corn stover; solids reduction between the first and second enrichments increased by a factor of four for switchgrass while solids reduction remained relatively constant for corn stover. Amplicon pyrosequencing analysis of small-subunit ribosomal RNA genes recovered from enriched samples indicated rapid changes in the microbial communities between the first and second enrichment with the simplified communities achieved by the third enrichment. The results demonstrate a successful approach for enrichment of unique microbial communities and enzymes active in a thermophilic high-solids environment.

Enzymatic pulp upgrade for producing high-value cellulose out of a Kraft paper pulp.

Science.gov (United States)

Hutterer, Christian; Kliba, Gerhard; Punz, Manuel; Fackler, Karin; Potthast, Antje

2017-07-01

The high-yield separation of polymeric parts from wood-derived lignocellulosic material is indispensable in biorefinery concepts. For the separation of cellulose and xylan from hardwood paper pulps to obtain pulps of high cellulose contents, simple alkaline extractions were found to be the most suitable technology, although having certain limitations. These are embodied by residual alkali resistant xylan incorporated in the pulp matrix. Further purification in order to produce pure cellulose with a low uniformity could be achieved selectively degrading residual xylan and depolymerizing the cellulose macromolecules by xylanase and cellulase. The latter help to adjust cellulose chain lengths for certain dissolving pulp grades while reducing the demand for ozone in subsequent TCF bleaching. Experiments applying different commercially available enzyme preparations revealed the dependency of xylanase performance on the residual xylan content in pulps being stimulated by additional cellulase usage. The action of the latter strongly depends on the cellulose allomorphy confirming the impact of the pulp morphology. Hence, the combined application of both types of enzymes offers a high potential for upgrading pulps in order to produce a pure and high-value cellulose product. Copyright © 2017 Elsevier Inc. All rights reserved.

Screening and characterization of thermo-active enzymes of biotechnological interest produced by thermophilic Bacillus isolated from hot springs in Tunisia.

Science.gov (United States)

Thebti, Wajdi; Riahi, Yosra; Gharsalli, Rawand; Belhadj, Omrane

2016-01-01

As part of the contribution to the global efforts in research of thermostable enzymes being of industrial interest, we focus on the isolation of thermophilic bacteria from Tunisian hot springs. Among the collection of 161 strains of thermophilic Bacillus isolated from different samples of thermal water in Tunisia, 20% are capable of growing at 100°C and the rest grow at 70°C or above. Preliminary activity tests on media supplemented with enzyme-substrates confirmed that 35 strains produced amylases, 37 - proteases, 43 - cellulases, 31 - xylanases and 37 - mannanases. The study of the effect of temperature on enzyme activity led to determination of the optimal temperatures of activities that vary between 60 and 100°C. Several enzymes were active at high temperatures (80, 90 and 100°C) and kept their activity even at 110°C. Several isolated strains producing enzymes with high optimal temperatures of activity were described for the first time in this study. Both strains B62 and B120 are producers of amylase, protease, cellulase, xylanase, and mannanase. The sequencing of 16S DNA identified isolated strains as Geobacillus kaustophillus, Aeribacillus pallidus, Geobacillus galactosidasus and Geobacillus toebii.

Cellulose- and xylan-degrading thermophilic anaerobic bacteria from biocompost.

Science.gov (United States)

Sizova, M V; Izquierdo, J A; Panikov, N S; Lynd, L R

2011-04-01

Nine thermophilic cellulolytic clostridial isolates and four other noncellulolytic bacterial isolates were isolated from self-heated biocompost via preliminary enrichment culture on microcrystalline cellulose. All cellulolytic isolates grew vigorously on cellulose, with the formation of either ethanol and acetate or acetate and formate as principal fermentation products as well as lactate and glycerol as minor products. In addition, two out of nine cellulolytic strains were able to utilize xylan and pretreated wood with roughly the same efficiency as for cellulose. The major products of xylan fermentation were acetate and formate, with minor contributions of lactate and ethanol. Phylogenetic analyses of 16S rRNA and glycosyl hydrolase family 48 (GH48) gene sequences revealed that two xylan-utilizing isolates were related to a Clostridium clariflavum strain and represent a distinct novel branch within the GH48 family. Both isolates possessed high cellulase and xylanase activity induced independently by either cellulose or xylan. Enzymatic activity decayed after growth cessation, with more-rapid disappearance of cellulase activity than of xylanase activity. A mixture of xylan and cellulose was utilized simultaneously, with a significant synergistic effect observed as a reduction of lag phase in cellulose degradation.

KINERJA ENZIM GANDA PADA PRETREATMENT MIKROALGA UNTUK PRODUKSI BIOETANOL

Directory of Open Access Journals (Sweden)

Padil

2016-12-01

Full Text Available The use of biomass of microalgae as a feedstock to produce bioethanol is very promising, it is caused by a large amount of carbohydrates contained in microalgae physiology cell. The main obstacle of enzymatic hydrolysis in order to produce bioethanol is the bound starch granules in a rigid cell wall. Therefore, pre-treatment steps needed to remove and convert complex carbohydrates into simple sugars before the fermentation process. Tetraselmis Chuii microalgae species are green microalgae (Chlorophyta in which the cell wall containing cellulose and hemicellulose as the main constituent, therefore, this study observe the effect of the use of cellulase enzymes and xylanase as a strategy to open up the cell walls of microalgae. Another investigated parameter is the enzyme concentration, temperature, pH, and methods of use of enzymes. The results showed that the highest yield of glucose obtained was 31.912% (w / w and is achieved under the conditions of a temperature of 45oC, pH of 4.5, the amount of biomass of microalgae as 5 g/L, the concentration of cellulase enzymes and xilanase 30% (w / w at 40 minute at mechanism using cellulase and xylanase enzymes simultaneously.

Impact of cell wall-degrading enzymes on water-holding capacity and solubility of dietary fibre in rye and wheat bran.

Science.gov (United States)

Petersson, Karin; Nordlund, Emilia; Tornberg, Eva; Eliasson, Ann-Charlotte; Buchert, Johanna

2013-03-15

Rye and wheat bran were treated with several xylanases and endoglucanases, and the effects on physicochemical properties such as solubility, viscosity, water-holding capacity and particle size as well as the chemical composition of the soluble and insoluble fractions of the bran were studied. A large number of enzymes with well-defined activities were used. This enabled a comparison between enzymes of different origins and with different activities as well as a comparison between the effects of the enzymes on rye and wheat bran. The xylanases derived from Bacillus subtilis were the most effective in solubilising dietary fibre from wheat and rye bran. There was a tendency for a higher degree of degradation of the soluble or solubilised dietary fibre in rye bran than in wheat bran when treated with most of the enzymes. None of the enzymes increased the water-holding capacity of the bran or the viscosity of the aqueous phase. The content of insoluble material decreased as the dietary fibre was solubilised by the enzymes. The amount of material that may form a network to retain water in the system was thereby decreased. © 2012 Society of Chemical Industry.

Studies on fibrolytic bacterium Butyrivibrio fibrisolvens isolated from sheep rumen

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Sawanon, S.

2007-03-01

Full Text Available Fibrolytic Butyrivibrio fibrisolvens was an attractive target for genetic engineering in rumen bacteria. The experiment was initiated in making culture collection of this species, some of which may be useful ascandidate strain in the future. Hay suspended in sheep rumen was used as the source of isolates. The source was enriched with filter paper degradation, diluted with an anaerobic solution and used for pure culturing bya roll tube technique. After colony forming, Gram-negative curved rods bacteria were selected and screened for further identification with volatile fatty acid (VFA profiling and 16S rDNA sequencing. Fibrolyticstrains were selected to find fibrolytic enzymes and attachment to and digestion of various fibers. Fortyseven strains of Gram-negative curved rods were isolated. After determining cellulase, xylanase activities and VFA profile, 2 strains were chosen and employed for 16S rDNA sequencing. Both strains producingbutyrate were B. fibrisolvens. Of these 2 strains, most fibrolytic S-28 was selected. The strain S-28 could degrade natural fibers but not cellulose and showed strong attachment to them. A strong xylanase activitywas detected and presence of cellulase, β-glucosidase, β-xylosidase, α-L-arabinofuranosidase and β- cellobiosidase were also demonstrated.

Enzyme Supplementation of Broiler Feeds with Reduced Mineral and Energy Levels

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JO Nunes

2015-12-01

Full Text Available ABSTRACT An experiment was conducted with the purpose of evaluating enzyme blends on the performance, carcass traits, and bone mineralization of broilers. In total, 928 one-day-old Cobb 500 male chicks of were used. A completely randomized design with four treatments with eight replicates of 29 birds each was adopted. The evaluated treatments were: 1- Positive Control (PC, feed containing the nutritional recommendations of the genetic company's manual; 2- Negative Control (NC, feed with reductions of 75 kcal/kg AME and 0.10 and 0.12 percent points of phosphorus and calcium, respectively; 3 - NC + enzyme blend (amylase + b-glucanase, xylanase, and phytase; 250 g/t of feed and 4 - NC + enzyme complex (phytase, amylase, xylanase, glucanase, pectinase, cellulase, and protease; 200 g/t of feed. Birds fed the diet with reduced nutrient levels (NC presented the worst performance (p0.05 carcass or parts yields. The broilers fed the reduced-nutrient and energy diet presented lower (p<0.05 tibial ash, calcium, and phosphorus contents that the other treatments. The use of enzyme combinations improved the performance of broilers fed diets with reduced nutrient and energy levels.

Purification and characterization of xylanases from Trichoderma inhamatum

Directory of Open Access Journals (Sweden)

L.A.O. Silva

2015-07-01

Conclusions: The enzymes present potential for application in industrial processes that require activity in acid conditions, wide-ranging pH stability, such as for animal feed, or juice and wine industries.

Degrading capability and activity of extracellular xylanase secreted ...

African Journals Online (AJOL)

DR. NJ TONUKARI

2012-04-26

Apr 26, 2012 ... Full Length Research Paper ... Peptone cellulose solution (PCS) medium was beneficial to the ... crude enzyme, and the weight loss of hemicellulose of corn stalk core and ... making the fiber more permeable to lignin removal.

Statistical optimization of xylanase production by Aspergillus niger ...

African Journals Online (AJOL)

SERVER

2008-03-04

Mar 4, 2008 ... 2Key Laboratory of Industrial Biotechnology, Ministry of Education, Jiangnan University, Wuxi 214122, P.R. China. 3School of ... of the main factors determining the economic of a process. Reducing the costs of enzyme production by optimization ..... tation periods during the potential industry application by.

Detection of Extracellular Enzyme Activities in Ganoderma neo-japonicum

OpenAIRE

Jo, Woo-Sik; Park, Ha-Na; Cho, Doo-Hyun; Yoo, Young-Bok; Park, Seung-Chun

2011-01-01

The ability of Ganoderma to produce extracellular enzymes, including β-glucosidase, cellulase, avicelase, pectinase, xylanase, protease, amylase, and ligninase was tested in chromogenic media. β-glucosidase showed the highest activity, among the eight tested enzymes. In particular, Ganoderma neo-japonicum showed significantly stronger activity for β-glucosidase than that of the other enzymes. Two Ganoderma lucidum isolates showed moderate activity for avicelase; however, Ganoderma neo-japonic...

Visualization of enzyme activities inside earthworm biopores by in situ soil zymography

Science.gov (United States)

Thu Duyen Hoang, Thi; Razavi, Bahar. S.; Blagodatskaya, Evgenia; Kuzyakov, Yakov

2015-04-01

Earthworms can strongly activate microorganisms, increase microbial and enzyme activities and consequently the turnover of native soil organic matter. In extremely dynamic microhabitats and hotspots as biopores made by earthworms, the in situ enzyme activities are a footprint of complex biotic interactions. The effect of earthworms on the alteration of enzyme activities inside biopores and the difference between bio-pores and earthworm-free soil was visualized by in situ soil zymography (Spohn and Kuzyakov, 2014). For the first time, we prepared quantitative imaging of enzyme activities in biopores. Furthermore, we developed the zymography technique by direct application of a substrate saturated membrane to the soil to obtain better spatial resolution. Lumbricus terrestris L. was placed into transparent box (15×20×15cm). Simultaneously, maize seed was sown in the soil. Control soil box with maize and without earthworm was prepared in the same way. After two weeks when bio-pore systems were formed by earthworm, we visualized in situ enzyme activities of five hydrolytic enzymes (β-glucosidase, cellobiohydrolase, chitinase, xylanase, leucine aminopeptidase) and phosphatase. Followed by non-destructive zymography, biopore samples and control soil were destructively collected to assay enzyme kinetics by fluorogenically labeled substrates method. Zymography showed higher activity of β-glucosidase, chitinase, xylanase and phosphatase in biopores comparing to bulk soil. These differences were further confirmed by fluorimetric microplate enzyme assay detected significant difference of Vmax in four above mentioned enzymes. Vmax of β-glucosidase, chitinase, xylanase and phosphatase in biopores is 68%, 108%, 50% and 49% higher than that of control soil. However, no difference in cellobiohydrolase and leucine aminopeptidase kinetics between biopores and control soil were detected. This indicated little effect of earthworms on protein and cellulose transformation in soil

Comparative Phenotype and Genome Analysis of Cellvibrio sp. PR1, a Xylanolytic and Agarolytic Bacterium from the Pearl River

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Zhangzhang Xie

2017-01-01

Full Text Available Cellvibrio sp. PR1 is a xylanolytic and agarolytic bacterium isolated from the Pearl River. Strain PR1 is closely related to Cellvibrio fibrivorans and C. ostraviensis (identity > 98%. The xylanase and agarase contents of strain PR1 reach up to 15.4 and 25.9 U/mL, respectively. The major cellular fatty acids consisted of C16:0 (36.7%, C18:0 (8.8%, C20:0 (6.8%, C15:0 iso 2-OH or/and C16:1ω7c (17.4%, and C18:1ω7c or/and C18:1ω6c (6.7%. A total of 251 CAZyme modules (63 CBMs, 20 CEs, 128 GHs, 38 GTs, and 2 PLs were identified from 3,730 predicted proteins. Genomic analysis suggested that strain PR1 has a complete xylan-hydrolyzing (5 β-xylanases, 16 β-xylosidases, 17 α-arabinofuranosidases, 9 acetyl xylan esterases, 4 α-glucuronidases, and 2 ferulic acid esterases and agar-hydrolyzing enzyme system (2 β-agarases and 2 α-neoagarooligosaccharide hydrolases. In addition, the main metabolic pathways of xylose, arabinose, and galactose are established in the genome-wide analysis. This study shows that strain PR1 contains a large number of glycoside hydrolases.

Richness of endophytic fungi isolated from Opuntia ficus-indica Mill. (Cactaceae) and preliminary screening for enzyme production.

Science.gov (United States)

Bezerra, J D P; Santos, M G S; Svedese, V M; Lima, D M M; Fernandes, M J S; Paiva, L M; Souza-Motta, C M

2012-05-01

Opuntia ficus-indica Mill. (forage cactus) is farmed with relative success in the semi-arid region of the Brazilian northeast for commercial purposes, particularly as forage and food. Endophytic microorganisms are those that can be isolated inside plant tissues and can be a new source to production of enzymes with different potentialities. The objective of this study was to describe the richness of endophytic fungi from O. ficus-indica and to detect the capacity of these species to produce extracellular hydrolytic enzymes. Forty-four endophytic fungi species were isolated. Among them, the most commonly found were Cladosporium cladosporioides (20.43%) and C. sphaerospermum (15.99%). Acremonium terricola, Monodictys castaneae, Penicillium glandicola, Phoma tropica and Tetraploa aristata are being reported for the first time as endophytic fungi for Brazil. The majority of isolated fungi exhibited enzymatic potential. Aspergillus japonicus and P. glandicola presented pectinolytic activity. Xylaria sp. was the most important among the other 14 species with positive cellulase activity. All 24 isolates analysed were xylanase-positive. Protease was best produced by isolate PF103. The results indicate that there is a significant richness of endophytic fungi in O. ficus-indica, and that these isolates indicate promising potential for deployment in biotechnological processes involving production of pectinases, cellulases, xylanases and proteases.

Streptomyces sp. TEM 33 possesses high lipolytic activity in solid-state fermentation in comparison with submerged fermentation.

Science.gov (United States)

Cadirci, Bilge Hilal; Yasa, Ihsan; Kocyigit, Ali

2016-01-01

Solid-state fermentation (SSF) is a bioprocess that doesn't need an excess of free water, and it offers potential benefits for microbial cultivation for bioprocesses and product development. In comparing the antibiotic production, few detailed reports could be found with lipolytic enzyme production by Streptomycetes in SSF. Taking this knowledge into consideration, we prefer to purify Actinomycetes species as a new source for lipase production. The lipase-producing strain Streptomyces sp. TEM 33 was isolated from soil and lipase production was managed by solid-state fermentation (SSF) in comparison with submerged fermentation (SmF). Bioprocess-affecting factors like initial moisture content, incubation time, and various carbon and nitrogen additives and the other enzymes secreted into the media were optimized. Lipase activity was measured as 1.74 ± 0.0005 U/g dry substrate (gds) by the p-nitrophenylpalmitate (pNPP) method on day 6 of fermentation with 71.43% final substrate moisture content. In order to understand the metabolic priority in SSF, cellulase and xylanase activity of Streptomyces sp. TEM33 was also measured. The microorganism degrades the wheat bran to its usable form by excreting cellulases and xylanases; then it secretes the lipase that is necessary for degrading the oil in the medium.

TESTING OF THE EFFICIENCY OF SOME ENZYMATIC MIXTURES, CONCERNING THE CONVERSION OF SEVERAL LIGNOCELLULOSIC BIOMASS’ SOURSES, TO REDUCING SUGARS

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RADIANA TAMBA-BEREHOIU

2008-05-01

Full Text Available Three lignocelluloses substrates have been used, as following: Mischantus, Maize stalk and Wheat bran, in order to obtain fermentescible sugars, which will be transformed into bioethanol. The substrates were hydrolysed using commercial enzymes: MethaPlus (b-glucanase, xylanase, cellulase, Veron 191 (xylanase, Hep C (cellulase. The hydrolysis was performed at 550 C, for 20 h, at pH = 5,5. The best results were obtained by using MethaPlus enzyme. The efficiency of hydrolysis was 110.80 % for Miscanthus, 126.15 % for maize stalk and 118.76 % for wheat bran, reported to the control. The most enhanced quantities of reducing sugars were obtained in maize stalk, namely: 126.15 % using MethaPlus, 112.07 % using Veron 191 and 113.52 % using Hep C. The wheat bran was hydrolysed with enzymatic mixtures, for emphasizing the reducing sugars’ grow, coming from residual starch’s content (flour. In comparison to the control, the efficiency of hydrolysis was of: 181.004 % for MethaPlus-Veron M4 mixture, 168.83 % for MethaPlus-Veron 393 mixture, 205.86 % for MethaPlus-BG a-malt mixture and of 176.57 % for MethaPlus-Veron MX mixture. The enzymatic mixture which contains BG a-malt was the most productive, the hydrolysis efficiency being superior to all other variants.

Optimization of endoglucanase production from thermophilic strain of Bacillus licheniformis RT-17 and its application for saccharification of sugarcane bagasse

International Nuclear Information System (INIS)

Tariq, R.; Qadir, F.; Ahmed, A.; Shariq, M.; Zafar, U.; Khan, S.A.

2018-01-01

Thermostable cellulases are required for a variety of commercial processes. Bacillus is a house of thermostable proteins. Screening of indigenously isolated strains of bacteria revealed the promising production of cellulase by a strain, RT-17, at 50 degree C. The strain was identified on the basis of biochemical and molecular characteristics as B. licheniformis. The factors affecting cellulase production from B. licheniformis RT-17 were evaluated for their significant effect using Plackett Burman Design and were optimized by employing Box-Behnken Design. The model predicted 9.808 IU/ml of endoglucanase (EG) under optimum conditions of 50 degree C; 10% inoculum size; pH 5; and 1% peptone in fermentation medium. Practically, a titer of 9.128 IU/ml was obtained, showed the validity of the model. The enzyme preparation from B. licheniformis RT-17 was applied in combination with xylanase and pectinase preparations from indigenous yeasts for the hydrolysis of sugarcane bagasse (SCB). A higher degree of synergy (7.1 folds) was observed when yeast pectinase was used with bacterial cellulase for the hydrolysis of alkali treated SCB. Whereas, the degree of synergy was lower when bacterial cellulase was mixed with yeast xylanase. The study revealed the possibility of utilization of combination of yeast and bacterial enzymes for biomass saccharification. (author)

Utilization of pineapple stem juice to enhance enzyme-hydrolytic efficiency for sugarcane bagasse after an optimized pre-treatment with alkaline peroxide

Energy Technology Data Exchange (ETDEWEB)

Monte, J.R.; Brienzo, M.; Milagres, A.M.F. [Department of Biotechnology, School of Engineering of Lorena, University of Sao Paulo - USP Estrada Municipal do Campinho, s/no - CP 116, 12602-810 Lorena, SP (Brazil)

2011-01-15

The enzymatic hydrolysis of sugarcane bagasse was investigated by treating a peroxide-alkaline bagasse with a pineapple stem juice, xylanase and cellulase. Pre-treatment procedures of sugarcane bagasse with alkaline hydrogen peroxide were evaluated and compared. Analyses were performed using 2{sup 4} factorial designs, with pre-treatment time, temperature, magnesium sulfate and hydrogen peroxide concentration as factors. The responses evaluated were the yield of cellobiose and glucose released from pretreated bagasse after enzymatic hydrolysis. The results show that the highest enzymatic conversion was obtained for bagasse using 2% hydrogen peroxide at 60 C for 16 h in the presence of 0.5% magnesium sulfate. Bagasse (5%) was treated with pineapple stem extract, which contains mixtures of protease and esterase, in combination with xylanase and cellulase. It was observed that the amount of glucose and cellobiose released from bagasse increased with the mixture of enzymes. It is believed that the enzymes present in pineapple extracts are capable of hydrolyze specific linkages that would facilitate the action of digesting plant cell walls enzymes. This increases the amount of glucose and other hexoses that are released during the enzymatic treatment and also reduces the amount of cellulase necessary in a typical hydrolysis. (author)

Nitrogen amendment of green waste impacts microbial community, enzyme secretion and potential for lignocellulose decomposition

Energy Technology Data Exchange (ETDEWEB)

Yu, Chaowei; Harrold, Duff R.; Claypool, Joshua T.; Simmons, Blake A.; Singer, Steven W.; Simmons, Christopher W.; VanderGheynst, Jean S.

2017-01-01

Microorganisms involved in biomass deconstruction are an important resource for organic waste recycling and enzymes for lignocellulose bioconversion. The goals of this paper were to examine the impact of nitrogen amendment on microbial community restructuring, secretion of xylanases and endoglucanases, and potential for biomass deconstruction. Communities were cultivated aerobically at 55 °C on green waste (GW) amended with varying levels of NH₄Cl. Bacterial and fungal communities were determined using 16S rRNA and ITS region gene sequencing and PICRUSt (Phylogenetic Investigation of Communities by Reconstruction of Unobserved States) was applied to predict relative abundance of genes involved in lignocellulose hydrolysis. Nitrogen amendment significantly increased secretion of xylanases and endoglucanases, and microbial activity; enzyme activities and cumulative respiration were greatest when nitrogen level in GW was between 4.13–4.56 wt% (g/g), but decreased with higher nitrogen levels. The microbial community shifted to one with increasing potential to decompose complex polymers as nitrogen increased with peak potential occurring between 3.79–4.45 wt% (g/g) nitrogen amendment. Finally, the results will aid in informing the management of nitrogen level to foster microbial communities capable of secreting enzymes that hydrolyze recalcitrant polymers in lignocellulose and yield rapid decomposition of green waste.

Screening of yeasts capable of producing cellulase-free xylanase

African Journals Online (AJOL)

Professor

2015-06-10

Jun 10, 2015 ... of their ability to degrade xylan, which was found in the medium by using agar degradation halos, the ... These enzymes are produced by molds, bacteria, yeasts ... collected, stored in sterile plastic bags and transported under.

Generation of transgenic mice producing fungal xylanase in the ...

African Journals Online (AJOL)

DR TONUKARI NYEROVWO

express exogenous digestive enzymes, since a single- stomached animal, such as a pig, can secret .... transgenic founder mice; 1 to15 are fifteen wild-type founder mice; M, marke; β-actin, endogenous control. (C) Identification of transgenic mice by ... 61.48±0.34%), gross energy digestibility (WT vs. TG = 68.79±0.51% vs.

Activity of cell wall degrading glycanases in methyl jasmonate-induced leaf abscission in Kalanchoe blossfeldiana

OpenAIRE

Marian Saniewski; Ewa Gajewska; Henryk Urbanek

2013-01-01

It was found previously that methyl jasmonate (JA-Me) induced leaf abscission in Kalanchoe blossfeldiana. In present studies it was shown that JA-Me markedly increased the total activities of cellulase, polygalacturonase, pectinase and xylanase in petioles, but did not affect activities of these enzymes in the blades and apical part of shoots of K. blossfeldiana. These results suggest that methyl jasmonate promotes the degradation of cell wall polysaccharides in the abscission zone and in thi...

Microplate-Based Evaluation of the Sugar Yield from Giant Reed, Giant Miscanthus and Switchgrass after Mild Chemical Pre-Treatments and Hydrolysis with Tailored Trichoderma Enzymatic Blends.

Science.gov (United States)

Cianchetta, Stefano; Bregoli, Luca; Galletti, Stefania

2017-11-01

Giant reed, miscanthus, and switchgrass are considered prominent lignocellulosic feedstocks to obtain fermentable sugars for biofuel production. The bioconversion into sugars requires a delignifying pre-treatment step followed by hydrolysis with cellulase and other accessory enzymes like xylanase, especially in the case of alkali pre-treatments, which retain the hemicellulose fraction. Blends richer in accessory enzymes than commercial mix can be obtained growing fungi on feedstock-based substrates, thus ten selected Trichoderma isolates, including the hypercellulolytic strain Trichoderma reesei Rut-C30, were grown on giant reed, miscanthus, or switchgrass-based substrates. The produced enzymes were used to saccharify the corresponding feedstocks, compared to a commercial enzymatic mix (6 FPU/g). Feedstocks were acid (H 2 SO 4 0.2-2%, w/v) or alkali (NaOH 0.02-0.2%, w/v) pre-treated. A microplate-based approach was chosen for most of the experimental steps due to the large number of samples. The highest bioconversion was generally obtained with Trichoderma harzianum Or4/99 enzymes (78, 89, and 94% final sugar yields at 48 h for giant reed, miscanthus, and switchgrass, respectively), with significant increases compared to the commercial mix, especially with alkaline pre-treatments. The differences in bioconversion yields were only partially caused by xylanases (maximum R 2  = 0.5), indicating a role for other accessory enzymes.

Production and immobilization of enzymes by solid-state fermentation of agroindustrial waste.

Science.gov (United States)

Romo Sánchez, Sheila; Gil Sánchez, Irene; Arévalo-Villena, María; Briones Pérez, Ana

2015-03-01

The recovery of by-products from agri-food industry is currently one of the major challenges of biotechnology. Castilla-La Mancha produces around three million tons of waste coming from olive oil and wine industries, both of which have a pivotal role in the economy of this region. For this reason, this study reports on the exploitation of grape skins and olive pomaces for the production of lignocellulosic enzymes, which are able to deconstruct the agroindustrial waste and, therefore, reuse them in future industrial processes. To this end, solid-state fermentation was carried out using two local fungal strains (Aspergillus niger-113 N and Aspergillus fumigatus-3). In some trials, a wheat supplementation with a 1:1 ratio was used to improve the growth conditions, and the particle size of the substrates was altered through milling. Separate fermentations were run and collected after 2, 4, 6, 8, 10 and 15 days to monitor enzymatic activity (xylanase, cellulase, β-glucosidase, pectinase). The highest values were recorded after 10 and 15 days of fermentation. The use of A. niger on unmilled grape skin yielded the best outcomes (47.05 U xylanase/g by-product). The multi-enzymatic extracts obtained were purified, freeze dried, and immobilized on chitosan by adsorption to assess the possible advantages provided by the different techniques.

Evaluation of certain food additives and contaminants. Eightieth report of the Joint FAO/WHO Expert Committee on Food Additives.

Science.gov (United States)

2016-01-01

This report represents the conclusions of a Joint FAO/WHO Expert Committee convened to evaluate the safety of various food additives and contaminants and to prepare specifications for identity and purity. The first part of the report contains a brief description of general considerations addressed at the meeting, including updates on matters of interest to the work of the Committee. A summary follows of the Committee's evaluations of technical, toxicological and/or dietary exposure data for seven food additives (benzoates; lipase from Fusarium heterosporum expressed in Ogataea polymorpha; magnesium stearate; maltotetraohydrolase from Pseudomonas stutzeri expressed in Bacillus licheniformis; mixed β-glucanase, cellulase and xylanase from Rasamsonia emersonii; mixed β-glucanase and xylanase from Disporotrichum dimorphosporum; polyvinyl alcohol (PVA)- polyethylene glycol (PEG) graft copolymer) and two groups of contaminants (non-dioxin-like polychlorinated biphenyls and pyrrolizidine alkaloids). Specifications for the following food additives were revised or withdrawn: advantame; annatto extracts (solavnt extracted bixin, ad solvent-extracted norbixin); food additives containing aluminium and/or silicon (aluminium silicate; calcium aluminium silicate; calcium silicate; silicon dioxide, amorphous; sodium aluminium silicate); and glycerol ester of gum rosin. Annexed to the report are tables or text summarizing the toxicological and dietary exposure information and information on specifications as well as the Committees recommendations on the food additives and contaminants considered at this meeting.

Enhancement in catalytic activity of Aspergillus niger XynB by selective site-directed mutagenesis of active site amino acids.

Science.gov (United States)

Wu, Xiuyun; Tian, Zhennan; Jiang, Xukai; Zhang, Qun; Wang, Lushan

2018-01-01

XynB from Aspergillus niger ATCC1015 (AnXynB) is a mesophilic glycoside hydrolase (GH) family 11 xylanase which holds great potentials in a wide variety of industrial applications. In the present study, the catalytic activity and stability of AnXynB were improved by a combination of computational and experimental approaches. Virtual mutation and molecular dynamics simulations indicated that the introduction of Glu and Asn altered the interaction network at the - 3 subsite. Interestingly, the double mutant S41N/T43E displayed 72% increase in catalytic activity when compared to the wild type (WT). In addition, it also showed a better thermostability than the WT enzyme. Kinetic determination of the T43E and S41N/T43E mutants suggested that the higher xylanase activity is probably due to the increasing binding affinity of enzyme and substrate. Consequently, the enzyme activity and thermostability of AnXynB was both increased by selective site-directed mutagenesis at the - 3 subsite of its active site architecture which provides a good example for a successfully engineered enzyme for potential industrial application. Moreover, the molecular evolution approach adopted in this study led to the design of a library of sequences that captures a meaningful functional diversity in a limited number of protein variants.

Optimization of sodium hydroxide pretreatment and enzyme loading for efficient hydrolysis of rice straw to improve succinate production by metabolically engineered Escherichia coli KJ122 under simultaneous saccharification and fermentation.

Science.gov (United States)

Sawisit, Apichai; Jampatesh, Surawee; Jantama, Sirima Suvarnakuta; Jantama, Kaemwich

2018-07-01

Rice straw was pretreated with sodium hydroxide (NaOH) before subsequent use for succinate production by Escherichia coli KJ122 under simultaneous saccharification and fermentation (SSF). The NaOH pretreated rice straw was significantly enhanced lignin removal up to 95%. With the optimized enzyme loading of 4% cellulase complex + 0.5% xylanase (endo-glucanase 67 CMC-U/g, β-glucosidase 26 pNG-U/g and xylanase 18 CMC-U/g dry biomass), total sugar conversion reached 91.7 ± 0.8% (w/w). The physicochemical analysis of NaOH pretreated rice straw indicated dramatical changes in its structure, thereby favoring enzymatic saccharification. In batch SSF, succinate production of 69.8 ± 0.3 g/L with yield and productivity of 0.84 g/g pretreated rice straw and 0.76 ± 0.02 g/L/h, respectively, was obtained. Fed-batch SSF significantly improved succinate concentration and productivity to 103.1 ± 0.4 g/L and 1.37 ± 0.07 g/L/h with a comparable yield. The results demonstrated a feasibility of sequential saccharification and fermentation of rice straw as a promising process for succinate production in industrial scale. Copyright © 2018 Elsevier Ltd. All rights reserved.

Combined subcritical water and enzymatic hydrolysis for reducing sugar production from coconut husk

Science.gov (United States)

Muharja, Maktum; Junianti, Fitri; Nurtono, Tantular; Widjaja, Arief

2017-05-01

Coconut husk wastes are abundantly available in Indonesia. It has a potential to be used into alternative renewable energy sources such as hydrogen using enzymatic hydrolysis followed by a fermentation process. Unfortunately, enzymatic hydrolysis is hampered by the complex structure of lignocellulose, so the cellulose component is hard to degrade. In this study, Combined Subcritical Water (SCW) and enzymatic hydrolysis are applied to enhance fermentable, thereby reducing production of sugar from coconut husk. There were two steps in this study, the first step was coconut husk pretreated by SCW in batch reactor at 80 bar and 150-200°C for 60 minutes reaction time. Secondly, solid fraction from the results of SCW was hydrolyzed using the mixture of pure cellulose and xylanase enzymes. Analysis was conducted on untreated and SCW-treated by gravimetric assay, liquid fraction after SCW and solid fraction after enzymatic hydrolysis using DNS assay. The maximum yield of reducing sugar (including xylose, arabinose glucose, galactose, mannose) was 1.254 gr per 6 gr raw material, representing 53.95% of total sugar in coconut husk biomass which was obtained at 150°C 80 bar for 60 minutes reaction time of SCW-treated and 6 hour of enzymatic hydrolysis using mixture of pure cellulose and xylanase enzymes (18.6 U /gram of coconut husk).

A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study

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Weili Gong

2018-03-01

Full Text Available Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger. This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger, we utilized functional proteomics to analyze the secreted proteins, sugar transporters, and intracellular proteins of A. niger An76 grown on xylan-based substrates. Results demonstrated that the complete xylanolytic enzyme system required for xylan degradation and composed of diverse isozymes was secreted in a sequential order. Xylan-backbone-degrading enzymes were preferentially induced by xylose or other soluble sugars, which efficiently produced large amounts of xylooligosaccharides (XOS and xylose; however, XOS was more efficient than xylose in triggering the expression of the key transcription activator XlnR, resulting in higher xylanase activity and shortening xylanase-production time. Moreover, the substituted XOS was responsible for improving the abundance of side-chain-degrading enzymes, specific transporters, and key reductases and dehydrogenases in the pentose catabolic pathway. Our findings indicated that industries might be able to improve the species and concentrations of xylan-degrading enzymes and shorten fermentation time by adding abundant intermediate products of natural xylan (XOS to cultures of filamentous fungi.

A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study

Science.gov (United States)

Gong, Weili; Dai, Lin; Zhang, Huaiqiang; Zhang, Lili; Wang, Lushan

2018-01-01

Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger. This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger, we utilized functional proteomics to analyze the secreted proteins, sugar transporters, and intracellular proteins of A. niger An76 grown on xylan-based substrates. Results demonstrated that the complete xylanolytic enzyme system required for xylan degradation and composed of diverse isozymes was secreted in a sequential order. Xylan-backbone-degrading enzymes were preferentially induced by xylose or other soluble sugars, which efficiently produced large amounts of xylooligosaccharides (XOS) and xylose; however, XOS was more efficient than xylose in triggering the expression of the key transcription activator XlnR, resulting in higher xylanase activity and shortening xylanase-production time. Moreover, the substituted XOS was responsible for improving the abundance of side-chain-degrading enzymes, specific transporters, and key reductases and dehydrogenases in the pentose catabolic pathway. Our findings indicated that industries might be able to improve the species and concentrations of xylan-degrading enzymes and shorten fermentation time by adding abundant intermediate products of natural xylan (XOS) to cultures of filamentous fungi. PMID:29623069

Morphological and enzymatic response of the thermotolerant fungus Fomes sp. EUM1 in solid state fermentation under thermal stress.

Science.gov (United States)

Ordaz-Hernández, Armando; Ortega-Sánchez, Eric; Montesinos-Matías, Roberto; Hernández-Martínez, Ricardo; Torres-Martínez, Daniel; Loera, Octavio

2016-08-01

Thermotolerance of the fungus Fomes sp. EUM1 was evaluated in solid state fermentation (SSF). This thermotolerant strain improved both hyphal invasiveness (38%) and length (17%) in adverse thermal conditions exceeding 30°C and to a maximum of 40°C. In contrast, hyphal branching decreased by 46% at 45°C. The production of cellulases over corn stover increased 1.6-fold in 30°C culture conditions, xylanases increased 2.8-fold at 40°C, while laccase production improved 2.7-fold at 35°C. Maximum production of lignocellulolytic enzymes was obtained at elevated temperatures in shorter fermentation times (8-6 days), although the proteases appeared as a thermal stress response associated with a drop in lignocellulolytic activities. Novel and multiple isoenzymes of xylanase (four bands) and cellulase (six bands) were secreted in the range of 20-150 kDa during growth in adverse temperature conditions. However, only a single laccase isoenzyme (46 kDa) was detected. This is the first report describing the advantages of a thermotolerant white-rot fungus in SSF. These results have important implications for large-scale SSF, where effects of metabolic heat are detrimental to growth and enzyme production, which are severely affected by the formation of high temperature gradients. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A Highly Efficient Xylan-Utilization System in Aspergillus niger An76: A Functional-Proteomics Study.

Science.gov (United States)

Gong, Weili; Dai, Lin; Zhang, Huaiqiang; Zhang, Lili; Wang, Lushan

2018-01-01

Xylan constituted with β-1,4-D-xylose linked backbone and diverse substituted side-chains is the most abundant hemicellulose component of biomass, which can be completely and rapidly degraded into fermentable sugars by Aspergillus niger . This is of great value for obtaining renewable biofuels and biochemicals. To clarify the underlying mechanisms associated with highly efficient xylan degradation, assimilation, and metabolism by A. niger , we utilized functional proteomics to analyze the secreted proteins, sugar transporters, and intracellular proteins of A. niger An76 grown on xylan-based substrates. Results demonstrated that the complete xylanolytic enzyme system required for xylan degradation and composed of diverse isozymes was secreted in a sequential order. Xylan-backbone-degrading enzymes were preferentially induced by xylose or other soluble sugars, which efficiently produced large amounts of xylooligosaccharides (XOS) and xylose; however, XOS was more efficient than xylose in triggering the expression of the key transcription activator XlnR, resulting in higher xylanase activity and shortening xylanase-production time. Moreover, the substituted XOS was responsible for improving the abundance of side-chain-degrading enzymes, specific transporters, and key reductases and dehydrogenases in the pentose catabolic pathway. Our findings indicated that industries might be able to improve the species and concentrations of xylan-degrading enzymes and shorten fermentation time by adding abundant intermediate products of natural xylan (XOS) to cultures of filamentous fungi.

An Alignment-Free Algorithm in Comparing the Similarity of Protein Sequences Based on Pseudo-Markov Transition Probabilities among Amino Acids.

Science.gov (United States)

Li, Yushuang; Song, Tian; Yang, Jiasheng; Zhang, Yi; Yang, Jialiang

2016-01-01

In this paper, we have proposed a novel alignment-free method for comparing the similarity of protein sequences. We first encode a protein sequence into a 440 dimensional feature vector consisting of a 400 dimensional Pseudo-Markov transition probability vector among the 20 amino acids, a 20 dimensional content ratio vector, and a 20 dimensional position ratio vector of the amino acids in the sequence. By evaluating the Euclidean distances among the representing vectors, we compare the similarity of protein sequences. We then apply this method into the ND5 dataset consisting of the ND5 protein sequences of 9 species, and the F10 and G11 datasets representing two of the xylanases containing glycoside hydrolase families, i.e., families 10 and 11. As a result, our method achieves a correlation coefficient of 0.962 with the canonical protein sequence aligner ClustalW in the ND5 dataset, much higher than those of other 5 popular alignment-free methods. In addition, we successfully separate the xylanases sequences in the F10 family and the G11 family and illustrate that the F10 family is more heat stable than the G11 family, consistent with a few previous studies. Moreover, we prove mathematically an identity equation involving the Pseudo-Markov transition probability vector and the amino acids content ratio vector.

Increased production of biomass-degrading enzymes by double deletion of creA and creB genes involved in carbon catabolite repression in Aspergillus oryzae.

Science.gov (United States)

Ichinose, Sakurako; Tanaka, Mizuki; Shintani, Takahiro; Gomi, Katsuya

2018-02-01

In a previous study, we reported that a double gene deletion mutant for CreA and CreB, which constitute the regulatory machinery involved in carbon catabolite repression, exhibited improved production of α-amylase compared with the wild-type strain and single creA or creB deletion mutants in Aspergillus oryzae. Because A. oryzae can also produce biomass-degrading enzymes, such as xylolytic and cellulolytic enzymes, we examined the production levels of those enzymes in deletion mutants in this study. Xylanase and β-glucosidase activities in the wild-type were hardly detected in submerged culture containing xylose as the carbon source, whereas those enzyme activities were significantly increased in the single creA deletion (ΔcreA) and double creA and creB deletion (ΔcreAΔcreB) mutants. In particular, the ΔcreAΔcreB mutant exhibited >100-fold higher xylanase and β-glucosidase activities than the wild-type. Moreover, in solid-state culture, the β-glucosidase activity of the double deletion mutant was >7-fold higher than in the wild-type. These results suggested that deletion of both creA and creB genes could also efficiently improve the production levels of biomass-degrading enzymes in A. oryzae. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Knocking out Bcsas1 in Botrytis cinerea impacts growth, development, and secretion of extracellular proteins, which decreases virulence.

Science.gov (United States)

Zhang, Zhanquan; Qin, Guozheng; Li, Boqiang; Tian, Shiping

2014-06-01

Pathogenic fungi usually secrete a series of virulence factors to the extracellular environment to facilitate infection. Rab GTPases play a central role in the secretory pathway. To explore the function of Rab/GTPase in filamentous fungi, we knocked out a Rab/GTPase family gene, Bcsas1, in Botrytis cinerea, an aggressive fungal pathogen that infects more than 200 plant species. A detailed analysis was conducted on the virulence and the secretory capability of the mutants. The results indicated that knockout of Bcsas1 inhibited hyphal development and reduced sporulation of B. cinerea on potato dextrose agar plates resulting in reduced virulence on various fruit hosts. Knocking out the Bcsas1 gene led to an accumulation of transport vesicles at the hyphal tip, significantly reduced extracellular protein content, and lowered the activity of polygalacturonase and xylanase in the extracellular medium. However, mutation of Bcsas1 did not affect the expression of genes encoding polygalacturonase and xylanase, suggesting the secretion of these two family enzymes was suppressed in the mutant. Moreover, a comparative analysis of the secretome provided further evidence that the disruption of Bcsas1 in mutant strains significantly depressed the secretion of polysaccharide hydrolases and proteases. The results indicate that Bcsas1, the Rab8/SEC4-like gene, plays a crucial role in development, protein secretion, and virulence of B. cinerea.

Electronic energy transfer involving carotenoid pigments in chlorosomes of two green bacteria: Chlorobium tepidum and Chloroflexus aurantiacus

DEFF Research Database (Denmark)

Melø, T B; Frigaard, N-U; Matsuura, K

2000-01-01

S) spectra, recorded at ambient temperature and under non-reducing or reducing conditions, are reported. The carotenoid (Car) pigments in both species transfer their singlet excitation to bacteriochlorophyll c (BChlc) with an efficiency which is high (between 0.5 and 0.8) but smaller than unity; BChlc...

UV mutagenesis of aspergillus niger for enzyme production in submerged fermentation

International Nuclear Information System (INIS)

Irfan, M.; Syed, Q.; Javed, J.

2011-01-01

The present study was conducted to improve the enzyme production from Aspergillus niger using UV mutation. Submerged fermentation was carried out in 250 ml Erlenmeyer flask using Vogel's media at 30 deg. C for six days. Results of this study revealed that UV-mutation enhanced CM Case activity up to two times while FPase activity up to three times as compared to the parental strain. For avicelase, xylanase and fungal biomass production, UV radiation has slight effect as compared to parental strain. (author)

Production of xylan-degrading enzymes by a Trichoderma harzianum strain

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Cacais André O.Guerreiro

2001-01-01

Full Text Available Trichoderma harzianum strain 4 produced extracellular xylan-degrading enzymes, namely beta-xylanase, beta-xylosidase and alpha-arabinofuranosidase, when grown in liquid medium cultures containing oat spelt xylan as inducer. Cellulase activity was not detected. The pattern of xylan-degrading enzymes induction was influenced by the form of xylan present in the medium. They were detected in different incubation periods. Electrophoretic separation of the proteins from liquid culture filtrates by SDS-PAGE showed a variety of bands with high and low molecular weights.

Biosorption of Cu (II onto chemically modified waste mycelium of Aspergillus awamori: Equilibrium, kinetics and modeling studies

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ZDRAVKA VELKOVA

2012-01-01

Full Text Available The biosorption potential of chemically modified waste mycelium of industrial xylanase-producing strain Aspergillus awamori for Cu (II removal from aqueous solutions was evaluated. The influence of pH, contact time and initial Cu (II concentration on the removal efficiency was evaluated. Maximum biosorption capacity was reached by sodium hydroxide treated waste fungal mycelium at pH 5.0. The Langmuir adsorption equation matched very well the adsorption equilibrium data in the studied conditions. The process kinetic followed the pseudo-firs order model.

Photoassisted Oxidation of Sulfides Catalyzed by Artificial Metalloenzymes Using Water as an Oxygen Source †

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Christian Herrero

2016-12-01

Full Text Available The Mn(TpCPP-Xln10A artificial metalloenzyme, obtained by non-covalent insertion of Mn(III-meso-tetrakis(p-carboxyphenylporphyrin [Mn(TpCPP, 1-Mn] into xylanase 10A from Streptomyces lividans (Xln10A as a host protein, was found able to catalyze the selective photo-induced oxidation of organic substrates in the presence of [RuII(bpy3]2+ as a photosensitizer and [CoIII(NH35Cl]2+ as a sacrificial electron acceptor, using water as oxygen atom source.

Activity of cell wall degrading glycanases in methyl jasmonate-induced leaf abscission in Kalanchoe blossfeldiana

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Marian Saniewski

2013-12-01

Full Text Available It was found previously that methyl jasmonate (JA-Me induced leaf abscission in Kalanchoe blossfeldiana. In present studies it was shown that JA-Me markedly increased the total activities of cellulase, polygalacturonase, pectinase and xylanase in petioles, but did not affect activities of these enzymes in the blades and apical part of shoots of K. blossfeldiana. These results suggest that methyl jasmonate promotes the degradation of cell wall polysaccharides in the abscission zone and in this way induces leaf abscission in Kalanchoe blossfeldiana.

Xylanase production by Aspergillus niger ANL 301 using agro - wastes

African Journals Online (AJOL)

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Cellulolytic enzyme expression and simultaneous conversion of lignocellulosic sugars into ethanol and xylitol by a new Candida tropicalis strain.

Science.gov (United States)

Mattam, Anu Jose; Kuila, Arindam; Suralikerimath, Niranjan; Choudary, Nettem; Rao, Peddy V C; Velankar, Harshad Ravindra

2016-01-01

Lignocellulosic ethanol production involves major steps such as thermochemical pretreatment of biomass, enzymatic hydrolysis of pre-treated biomass and the fermentation of released sugars into ethanol. At least two different organisms are conventionally utilized for producing cellulolytic enzymes and for ethanol production through fermentation, whereas in the present study a single yeast isolate with the capacity to simultaneously produce cellulases and xylanases and ferment the released sugars into ethanol and xylitol has been described. A yeast strain isolated from soil samples and identified as Candida tropicalis MTCC 25057 expressed cellulases and xylanases over a wide range of temperatures (32 and 42 °C) and in the presence of different cellulosic substrates [carboxymethylcellulose and wheat straw (WS)]. The studies indicated that the cultivation of yeast at 42 °C in pre-treated hydrolysate containing 0.5 % WS resulted in proportional expression of cellulases (exoglucanases and endoglucanases) at concentrations of 114.1 and 97.8 U g(-1) ds, respectively. A high xylanase activity (689.3 U g(-1) ds) was also exhibited by the yeast under similar growth conditions. Maximum expression of cellulolytic enzymes by the yeast occurred within 24 h of incubation. Of the sugars released from biomass after pretreatment, 49 g L(-1) xylose was aerobically converted into 15.8 g L(-1) of xylitol. In addition, 25.4 g L(-1) glucose released after the enzymatic hydrolysis of biomass was fermented by the same yeast to obtain an ethanol titer of 7.3 g L(-1). During the present study, a new strain of C. tropicalis was isolated and found to have potential for consolidated bioprocessing (CBP) applications. The strain could grow in a wide range of process conditions (temperature, pH) and in the presence of lignocellulosic inhibitors such as furfural, HMF and acetic acid. The new yeast produced cellulolytic enzymes over a wide temperature range and in the presence of

Development of eco-friendly process for the production of bioethanol from banana peel using inhouse developed cocktail of thermo-alkali-stable depolymerizing enzymes.

Science.gov (United States)

Prakash, Heena; Chauhan, Prakram Singh; General, Thiyam; Sharma, A K

2018-03-29

Conversion of agro-industrial wastes to energy is an innovative approach for waste valorization and management which also mitigates environmental pollution. In this view, present study investigated the feasibility of producing bioethanol from banana peels using cocktail of depolymerizing enzyme/s. We isolated Geobacillus stearothermophilus HPA19 from natural resource which produces cocktail of thermo-alkali-stable xylano-pectino-cellulolytic enzyme/s using wheat bran within 24 h. The optimal temperature and pH for xylanase, filter paper cellulase and pectinase were 80, 70 and 80 °C, and 9.0, 8.0 and 9.0, respectively. Cocktail enzymes showed stability at high temperature (80 °C) and pH (10.0). Ni 2+ and Zn 2+ promoted the relative activity of xylanase and FPase, whereas Na + , Ca 2+ and K + promoted pectinase activity. Cocktail was assessed in saccharification of banana peel. Reducing sugar obtained (37.06 mg ml -1 ) after one variable at a time (OVAT) method is greatly influenced by enzyme dose. Further, response surface methodology was used to optimize saccharification leading to twofold increase in reducing sugar. Maximum ethanol production (21.1 gl -1 ) was achieved through fermentation giving the efficiency of 76.5% within 30 h. Hence utilization of waste biomass for production of value-added products through biotechnological intervention not only helps to combat environmental pollution but also contributes significantly to the economy.

Cloning, expression and characterization of β-xylosidase from Aspergillus niger ASKU28.

Science.gov (United States)

Choengpanya, Khuanjarat; Arthornthurasuk, Siriphan; Wattana-amorn, Pakorn; Huang, Wan-Ting; Plengmuankhae, Wandee; Li, Yaw-Kuen; Kongsaeree, Prachumporn T

2015-11-01

β-Xylosidases catalyze the breakdown of β-1,4-xylooligosaccharides, which are produced from degradation of xylan by xylanases, to fermentable xylose. Due to their important role in xylan degradation, there is an interest in using these enzymes in biofuel production from lignocellulosic biomass. In this study, the coding sequence of a glycoside hydrolase family 3 β-xylosidase from Aspergillus niger ASKU28 (AnBX) was cloned and expressed in Pichia pastoris as an N-terminal fusion protein with the α-mating factor signal sequence (α-MF) and a poly-histidine tag. The expression level was increased to 5.7 g/l in a fermenter system as a result of optimization of only five codons near the 5' end of the α-MF sequence. The recombinant AnBX was purified to homogeneity through a single-step Phenyl Sepharose chromatography. The enzyme exhibited an optimal activity at 70°C and at pH 4.0-4.5, and a very high kinetic efficiency toward a xyloside substrate. AnBX demonstrated an exo-type activity with retention of the β-configuration, and a synergistic action with xylanase in hydrolysis of beechwood xylan. This study provides comprehensive data on characterization of a glycoside hydrolase family 3 β-xylosidase that have not been determined in any prior investigations. Our results suggested that AnBX may be useful for degradation of lignocellulosic biomass in bioethanol production, pulp bleaching process and beverage industry. Copyright © 2015 Elsevier Inc. All rights reserved.

Strong cellulase inhibition by Mannan polysaccharides in cellulose conversion to sugars.

Science.gov (United States)

Kumar, Rajeev; Wyman, Charles E

2014-07-01

Cellulase enzymes contribute a major fraction of the total cost for biological conversion of lignocellulosic biomass to fuels and chemicals. Although a several fold reduction in cellulase production costs and enhancement of cellulase activity and stability have been reported in recent years, sugar yields are still lower at low enzyme doses than desired commercially. We recently reported that hemicellulose xylan and its oligomers strongly inhibit cellulase and that supplementation of cellulase with xylanase and β-xylosidase would significantly reduce such inhibition. In this study, mannan polysaccharides and their enzymatically prepared hydrolyzates were discovered to be strongly inhibitory to fungal cellulase in cellulose conversion (>50% drop in % relative conversion), even at a small concentration of 0.1 g/L, and inhibition was much greater than experienced by other known inhibitors such as cellobiose, xylooligomers, and furfural. Furthermore, cellulase inhibition dramatically increased with heteromannan loading and mannan substitution with galactose side units. In general, enzymatically prepared hydrolyzates were less inhibitory than their respective mannan polysaccharides except highly substituted ones. Supplementation of cellulase with commercial accessory enzymes such as xylanase, pectinase, and β-glucosidase was effective in greatly relieving inhibition but only for less substituted heteromannans. However, cellulase supplementation with purified heteromannan specific enzymes relieved inhibition by these more substituted heteromannans as well, suggesting that commercial preparations need to have higher amounts of such activities to realize high sugar yields at the low enzyme protein loadings needed for low cost fuels production. © 2014 Wiley Periodicals, Inc.

Production of hydrolytic enzymes by the plant pathogenic fungus Myrothecium verrucaria in submerged cultures Produção de enzimas hidrolíticas pelo fungo fitopatogênico Myrothecium verrucaria em culturas submersas

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Fabiana Guillen Moreira

2005-03-01

Full Text Available The capability of the plant pathogenic fungus Myrothecium verrucaria to produce extracellular hydrolytic enzymes in submerged cultures was studied using several substrates. The fungus was able to produce different depolymerases and glycosidases, being xylanase, pectinase and protease the most important. Lipase was found in cultures developed in the presence of olive oil, while protease activity was detected in all cultures. Xylanase and pectinase were optimally active at pH 4.5-5.5, while protease was active in a large range of pH 3.5 to 11.0. All three enzymes were maximally active at 40ºC and they were stable for several hours at temperature up to 50ºC.A capacidade do fungo fitopatogênico Myrothecium verrucaria produzir enzimas hidrolíticas extracelulares em culturas submersas foi estudada utilizando diversos substratos. O fungo foi capaz de produzir diferentes depolimerases e glicosidases, sendo xilanases, pectinases e proteases as mais importantes. Atividade lipase foi encontrada nos filtrados das culturas desenvolvidas na presença de óleo de oliva, enquanto atividade proteolítica foi detectada em todas as culturas. Xilanase e pectinase foram otimamente ativas em pH 4,5 a 5,5, enquanto protease foi ativa em ampla faixa de pH (3,5 a 11,0. As três enzimas foram otimamente ativas 40ºC e estáveis por várias horas a temperaturas até 50ºC.

Three feruloyl esterases in Cellulosilyticum ruminicola H1 act synergistically to hydrolyze esterified polysaccharides.

Science.gov (United States)

Li, Jiabao; Cai, Shichun; Luo, Yuanming; Dong, Xiuzhu

2011-09-01

Feruloyl esterases (Faes) constitute a subclass of carboxyl esterases that specifically hydrolyze the ester linkages between ferulate and polysaccharides in plant cell walls. Until now, the described microbial Faes were mainly from fungi. In this study, we report that Cellulosilyticum ruminicola H1, a previously described fibrolytic rumen bacterium, possesses three different active feruloyl esterases, FaeI, FaeII, and FaeIII. Phylogenetic analysis classified the described bacterial Faes into two types, FaeI and FaeII in type I and FaeIII in type II. Substrate specificity assays indicated that FaeI is more active against the ester bonds in natural hemicelluloses and FaeIII preferentially attacks the ferulate esters with a small moiety, such as methyl groups, while FaeII is active on both types of substrates. Among the three feruloyl esterase genes, faeI was the only one induced significantly by xylose and xylan, while pectin appeared to moderately induce the three genes during the late log phase to stationary phase. Western blot analysis determined that FaeI and FaeIII were secreted and cytoplasmic proteins, respectively, whereas FaeII seemed to be cell associated. The addition of FaeI and FaeII but not FaeIII enhanced the activity of a xylanase on maize cob, suggesting a synergy of the former two with xylanase. Hence, we propose that the three feruloyl esterases work in concert to hydrolyze ferulate esters in natural hemicelluloses.

Feasibility test of utilizing Saccharophagus degradans 2-40(T) as the source of crude enzyme for the saccharification of lignocellulose.

Science.gov (United States)

Jung, Young Hoon; Kim, Hyun Kyung; Song, Du-Sup; Choi, In-Geol; Yang, Taek Ho; Lee, Hee Jong; Seung, Doyoung; Kim, Kyoung Heon

2014-04-01

In the conversion of lignocellulose into high-value products, including fuels and chemicals, the production of cellulase and the enzymatic hydrolysis for producing fermentable sugar are the largest contributors to the cost of production of the final products. The marine bacterium Saccharophagus degradans 2-40(T) can degrade more than ten different complex polysaccharides found in the ocean, including cellulose and xylan. Accordingly, S. degradans has been actively considered as a practical source of crude enzymes needed for the saccharification of lignocellulose to produce ethanol by others including a leading commercial company. However, the overall enzyme system of S. degradans for hydrolyzing cellulose and hemicellulose has not been quantitatively evaluated yet in comparison with commercial enzymes. In this study, the inductions and activities of cellulase and xylanase of cell-free lysate of S. degradans were investigated. The growth of S. degradans cells and the activities of cellulase and xylanase were promoted by adding 2 % of cellulose and xylan mixture (cellulose:xylan = 4:3 in mass ratio) to the aquarium salt medium supplemented with 0.2 % glucose. The specific cellulase activity of the cell-free lysate of S. degradans, as determined by the filter paper activity assay, was approximately 70 times lower than those of commercial cellulases, including Celluclast 1.5 L and Accellerase 1000. These results imply that significant improvement in the cellulase activity of S. degradans is needed for the industrial uses of S. degradans as the enzyme source.

Hyperthermostable cellulolytic and hemicellulolytic enzymes and their biotechnological applications

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Tipparat Hongpattarakere

2002-07-01

Full Text Available Hyperthermal cellulases and hemicellulases have been intensively studied due to their highly potential applications at extreme temperatures, which mimic industrial processes involving cellulose and hemicellulose degradation. More than 50 species of hyperthermophiles have been isolated, many of which possess hyperthermal enzymes required for hydrolyzing cellulose and hemicelluloses. Endoglucanases, exoglucanases, cellobiohydrolases, xylanases, β-glucosidase and β-galactosidase, which are produced by the hyperthermophiles, are resistant to boiling temperature. The characteristics of these enzymes and the ability to maintain their functional integrity at high temperature as well as their biotechnological application are discussed.

Identification of thermostable β-xylosidase activities produced by Aspergillus brasiliensis and Aspergillus niger

DEFF Research Database (Denmark)

Pedersen, Mads; Lauritzen, Henrik Klitgaard; Frisvad, Jens Christian

2007-01-01

Twenty Aspergillus strains were evaluated for production of extracellular cellulolytic and xylanolytic activities. Aspergillus brasiliensis, A. niger and A. japonicus produced the highest xylanase activities with the A. brasiliensis and A. niger strains producing thermostable beta......-xylosidases. The beta-xylosidase activities of the A. brasiliensis and A. niger strains had similar temperature and pH optima at 75 degrees C and pH 5 and retained 62% and 99%, respectively, of these activities over 1 h at 60 degrees C. At 75 degrees C, these values were 38 and 44%, respectively. Whereas A. niger...

Celluloytic enzymes, nucleic acids encoding them and methods for making and using them

Energy Technology Data Exchange (ETDEWEB)

Gray, Kevin A; Zhao, Lishan; Cayouette, Michelle H

2015-11-04

The invention is directed to polypeptides having any cellulolytic activity, e.g., a cellulase activity, e.g., endoglucanase, cellobiohydrolase, beta-glucosidase, xylanase, mannanse, .beta.-xylosidase, arabinofuranosidase, and/or oligomerase activity, including thermostable and thermotolerant activity, and polynucleotides encoding these enzymes, and making and using these polynucleotides and polypeptides. The polypeptides of the invention can be used in a variety of pharmaceutical, agricultural, food and feed processing and industrial contexts. The invention also provides compositions or products of manufacture comprising mixtures of enzymes comprising at least one enzyme of this invention.

Enzyme activity screening of thermophilic bacteria isolated from Dusun Tua Hot Spring, Malaysia

Science.gov (United States)

Msarah, Marwan; Ibrahim, Izyanti; Aqma, Wan Syaidatul

2018-04-01

Thermophilic bacteria have biotechnological importance due to the availability of unique enzymes which are stable in extreme circumstances. The aim of this study includes to isolate thermophilic bacteria from hot spring and screen for important enzyme activities. Water samples from the Dusun Tua Hot Spring were collected and the physiochemical characterisation of water was measured. Eight thermophilic bacteria were isolated and determined to have at least three strong enzyme activity including protease, lipase, amylase, cellulase, pectinase and xylanase. The results showed that HuluC2 displayed all the enzyme activities and can be further studied.

Celluloytic enzymes, nucleic acids encoding them and methods for making and using them

Science.gov (United States)

Gray, Kevin A.; Zhao, Lishan; Cayouette, Michelle H.

2015-09-08

The invention is directed to polypeptides having any cellulolytic activity, e.g., a cellulase activity, e.g., endoglucanase, cellobiohydrolase, beta-glucosidase, xylanase, mannanse, .beta.-xylosidase, arabinofuranosidase, and/or oligomerase activity, including thermostable and thermotolerant activity, and polynucleotides encoding these enzymes, and making and using these polynucleotides and polypeptides. The polypeptides of the invention can be used in a variety of pharmaceutical, agricultural, food and feed processing and industrial contexts. The invention also provides compositions or products of manufacture comprising mixtures of enzymes comprising at least one enzyme of this invention.

Pretreatments and enzymatic hydrolysis of sugarcane bagasse aiming at the enhancement of the yield of glucose and xylose

Directory of Open Access Journals (Sweden)

A. de A. Guilherme

Full Text Available ABSTRACT This work studied the enzymatic hydrolysis of sugarcane bagasse aiming at the production of glucose and xylose. The bagasse was subjected to two different pretreatments: combined acid and alkalinepretreatment and hydrogen peroxidepretreatment. The enzymatic hydrolysis was optimized and a kinetic study was carried out in a stirred tank reactor (STR in batch mode. Optimal conditions were obtained by subjecting the bagasse to the hydrogen peroxide pretreatment followed by enzymatic hydrolysis. The addition of xylanases to the enzymatic mixture improved the production of fermentable sugars by 48%.

Multifarious activities of cellulose degrading bacteria from Koala (Phascolarctos cinereus) faeces.

Science.gov (United States)

Singh, Surender; Thavamani, Palanisami; Megharaj, Mallavarapu; Naidu, Ravi

2015-01-01

Cellulose degrading bacteria from koala faeces were isolated using caboxymethylcellulose-Congo red agar, screened in vitro for different hydrolytic enzyme activities and phylogenetically characterized using molecular tools. Bacillus sp. and Pseudomonas sp. were the most prominent bacteria from koala faeces. The isolates demonstrated good xylanase, amylase, lipase, protease, tannase and lignin peroxidase activities apart from endoglucanase activity. Furthermore many isolates grew in the presence of phenanthrene, indicating their probable application for bioremediation. Potential isolates can be exploited further for industrial enzyme production or in bioremediation of contaminated sites.

The cellulosome--a treasure-trove for biotechnology.

Science.gov (United States)

Bayer, E A; Morag, E; Lamed, R

1994-09-01

The cellulases of many cellulolytic bacteria are organized into discrete multienzyme complexes, called cellulosomes. The multiple subunits of cellulosomes are composed of numerous functional domains, which interact with each other and with the cellulosic substrate. One of these subunits comprises a distinctive new class of noncatalytic scaffolding polypeptide, which selectively integrates the various cellulase and xylanase subunits into the cohesive complex. Intelligent application of cellulosome hybrids and chimeric constructs of cellulosomal domains should enable better use of cellulosic biomass and may offer a wide range of novel applications in research, medicine and industry.

[Comparative characteristics of microbial proteases by the level of hydrolysis of protein substrates].

Science.gov (United States)

Rimareva, L V; Overchenko, M B; Serba, E M; Trifonova, V V

1997-01-01

Screening of enzyme preparations displaying a maximum proteolytic activity at pH 4.0-5.5 and effecting deep proteolysis of plant proteins was performed. Amyloprotooryzin prepared from Aspergillus oryzae 387 containing a complex of proteolytic enzymes was the most effective. The amino acid composition of the hydrolysates obtained was studied. Amyloprotooryzin increased the contents of amino acids by 108-227%, depending on the substrate used. The enzymatic complex of amyloprotooryzin was studied; in addition, proteases, alpha-amylase, exo-beta-glucanase, and xylanase were detected in the complex.

Cellulolytic and xylanolytic potential of high β-glucosidase-producing Trichoderma from decaying biomass.

Science.gov (United States)

Okeke, Benedict C

2014-10-01

Availability, cost, and efficiency of microbial enzymes for lignocellulose bioconversion are central to sustainable biomass ethanol technology. Fungi enriched from decaying biomass and surface soil mixture displayed an array of strong cellulolytic and xylanolytic activities. Strains SG2 and SG4 produced a promising array of cellulolytic and xylanolytic enzymes including β-glucosidase, usually low in cultures of Trichoderma species. Nucleotide sequence analysis of internal transcribed spacer 2 (ITS2) region of rRNA gene revealed that strains SG2 and SG4 are closely related to Trichoderma inhamatum, Trichoderma piluliferum, and Trichoderma aureoviride. Trichoderma sp. SG2 crude culture supernatant correspondingly displayed as much as 9.84 ± 1.12, 48.02 ± 2.53, and 30.10 ± 1.11 units mL(-1) of cellulase, xylanase, and β-glucosidase in 30 min assay. Ten times dilution of culture supernatant of strain SG2 revealed that total activities were about 5.34, 8.45, and 2.05 orders of magnitude higher than observed in crude culture filtrate for cellulase, xylanase, and β-glucosidase, respectively, indicating that more enzymes are present to contact with substrates in biomass saccharification. In parallel experiments, Trichoderma species SG2 and SG4 produced more β-glucosidase than the industrial strain Trichoderma reesei RUT-C30. Results indicate that strains SG2 and SG4 have potential for low cost in-house production of primary lignocellulose-hydrolyzing enzymes for production of biomass saccharides and biofuel in the field.

ISOLATION AND LIGNOCELLULOLYTIC ACTIVITIES OF FIBER-DIGESTING BACTERIA FROM DIGESTIVE TRACT OF TERMITE (Cryptothermes sp.

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B.I.M. Tampoebolon

2015-09-01

Full Text Available The objectives of this study were to obtain the fiber-digesting bacteria isolates from termitedigestive tract and to determine the optimum conditions of growth and production of cellulase, xylanaseand ligninase enzyme of isolate. The first study was conducted to isolate and select the fiber-digestingbacteria from the digestive tract of termites based on the highest activity of cellulolytic (S, xylanolytic(X and lignolytic (L. The second study was optimation of the growth conditions of bacteria and theenzyme production due to effect of rice straw substrate and nitrogen. The material used were dry woodtermites, rice straw, and culture medium. The design used was a completely randomized factorial design,in which the first factor was rice straw substrate (1, 2, and 3% W/V, while the second factor wasnitrogen (0.1, 0.2 and 0.3% W/V. Variables measured were cellulase, xylanase and ligninase activities.Results of the first sudy showed that the isolates obtained consisted of 3 types, those were cellulolyticbacteria (S1, S2, and S3, 3 types of bacteria xylanolytic (X1, X2, and X3 and 3 types of bacteria lignolytic(L1, L2, and L3. Meanwhile, results of the second study showed that isolates of S2, X3, and L1 had thehighest activity, those were 1.894 U/mL, 1.722 U/mL and 0.314 U/mL, respectively. In conclusion, the addition of 1% level of rice straw substrate and 0.3% of nitrogen showed the highest enzyme activity oncellulase, xylanase and ligninase.

Novel thermophilic hemicellulases for the conversion of lignocellulose for second generation biorefineries.

Science.gov (United States)

Cobucci-Ponzano, Beatrice; Strazzulli, Andrea; Iacono, Roberta; Masturzo, Giuseppe; Giglio, Rosa; Rossi, Mosè; Moracci, Marco

2015-10-01

The biotransformation of lignocellulose biomasses into fermentable sugars is a very complex procedure including, as one of the most critical steps, the (hemi) cellulose hydrolysis by specific enzymatic cocktails. We explored here, the potential of stable glycoside hydrolases from thermophilic organisms, so far not used in commercial enzymatic preparations, for the conversion of glucuronoxylan, the major hemicellulose of several energy crops. Searches in the genomes of thermophilic bacteria led to the identification, efficient production, and detailed characterization of novel xylanase and α-glucuronidase from Alicyclobacillus acidocaldarius (GH10-XA and GH67-GA, respectively) and a α-glucuronidase from Caldicellulosiruptor saccharolyticus (GH67-GC). Remarkably, GH10-XA, if compared to other thermophilic xylanases from this family, coupled good specificity on beechwood xylan and the best stability at 65 °C (3.5 days). In addition, GH67-GC was the most stable α-glucuronidases from this family and the first able to hydrolyse both aldouronic acid and aryl-α-glucuronic acid substrates. These enzymes, led to the very efficient hydrolysis of beechwood xylan by using 7- to 9-fold less protein (concentrations thermophilic enzymes. In addition, remarkably, together with a thermophilic β-xylosidase, they catalyzed the production of xylose from the smart cooking pre-treated biomass of one of the most promising energy crops for second generation biorefineries. We demonstrated that search by the CAZy Data Bank of currently available genomes and detailed enzymatic characterization of recombinant enzymes allow the identification of glycoside hydrolases with novel and interesting properties and applications. Copyright © 2015 Elsevier Inc. All rights reserved.

Cellulolytic and xylanolytic enzymes from thermophilic Aspergillus terreus RWY.

Science.gov (United States)

Sharma, Reetika; Kocher, Gurvinder Singh; Bhogal, Ravinder Singh; Oberoi, Harinder Singh

2014-12-01

Thermophilic Aspergillus terreus RWY produced cellulases and xylanases in optimal concentrations at 45 °C in solid state fermentation process, though enzyme production was also observed at 50 and 55 °C. Filter paper cellulase (FP), endoglucanase (EG), β-glucosidase (BGL), cellobiohydrolase (CBH), xylanase, β-xylosidase, α-L-arabinofuranosidase and xylan esterase activities for A. terreus RWY at 45 °C in 72 h were 11.3 ± 0.65, 103 ± 6.4, 122.5 ± 8.7, 10.3 ± 0.66, 872 ± 22.5, 22.1 ± 0.75, 126.4 ± 8.4 and 907 ± 15.5 U (g-ds)(-1) , respectively. Enzyme was optimally active at temperatures and pH ranging between 50-60 °C and 4.0-6.0, respectively. The half life (T1/2 ) of 270 and 240 min at 70 and 75 °C, respectively for the enzyme indicates its stability at higher temperatures. The addition of MnCl2 , CoCl2 , and FeCl3 significantly enhanced cellulase activity. Enzyme demonstrated multiplicity by having seven, one and three isoform(s) for EG, CBH and BGL, respectively. Significant production of functionally active consortium of cellulolytic and xylanolytic enzymes from A. terreus RWY makes it a potential candidate in bioprocessing applications. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biological conversion of forage sorghum biomass to ethanol by steam explosion pretreatment and simultaneous hydrolysis and fermentation at high solid content

Energy Technology Data Exchange (ETDEWEB)

Manzanares, Paloma; Ballesteros, Ignacio; Negro, Maria Jose; Oliva, Jose Miguel; Gonzalez, Alberto; Ballesteros, Mercedes [Renewable Energy Department-CIEMAT, Biofuels Unit, Madrid (Spain)

2012-06-15

In this work, forage sorghum biomass was studied as feedstock for ethanol production by a biological conversion process comprising the steps of hydrothermal steam explosion pretreatment, enzymatic hydrolysis with commercial enzymes, and fermentation with the yeast Saccharomyces cerevisiae. Steam explosion conditions were optimized using a response surface methodology considering temperature (180-230 C) and time (2-10 min). Sugar recovery in the pretreatment and the enzymatic digestibility of the pretreated solid were used to determine the optimum conditions, i.e., 220 C and 7 min. At these conditions, saccharification efficiency attained 89 % of the theoretical and the recovery of xylose in the prehydrolyzate accounted for 35 % of the amount of xylose present in raw material. Then, a simultaneous hydrolysis and fermentation (SSF) process was tested at laboratory scale on the solid fraction of forage sorghum pretreated at optimum condition, in order to evaluate ethanol production. The effect of the enzyme dose and the supplementation with xylanase enzyme of the cellulolytic enzyme cocktail was studied at increasing solid concentration up to 18 % (w/w) in SSF media. Results show good performance of SSF in all consistencies tested with a significant effect of increasing enzyme load in SSF yield and final ethanol concentration. Xylanase supplementation allows increasing solid concentration up to 18 % (w/w) with good SSF performance and final ethanol content of 55 g/l after 4-5 days. Based on this result, about 190 l of ethanol could be obtained from 1 t of untreated forage sorghum, which means a transformation yield of 85 % of the glucose contained in the feedstock. (orig.)

Screening of thermotolerant microorganisms and application for oil separation from palm oil mill wastewater

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Aran H-Kittikun

2007-05-01

Full Text Available The characteristics of palm oil mill wastewater (POMW were brown color, pH 3.8-4.3, temperature 48-55oC, total solids 68.2-82.1 g/l, suspended solids 26.2-65.6 g/l, oil and grease 19.1-25.1 g/l, COD 49.9-160.7g/l and BOD 32.5-75.3 g/l. After centrifugation (3,184 xg of 50 ml POMW for 10 min, the POMW was separated into 3 layers: top (oil, middle (supernatant and bottom layer (sediment. The sediment containeddry weight 1.19 g and oil and grease 1.07 g. In order to release oil and grease trapped in palm fiber debris in the POMW, cellulase- and/or xylanase-enzyme-producing and thermotolerant microorganisms wereisolated. The isolates SO1 and SO2 were isolated from soil near the first anaerobic pond of the palm oil mill. They were aerobic, Gram positive, rod shaped, thermotolerant microorganisms and produced cellulase 12.11 U/ml (3 days and 7.2 U/ml (4 days, and xylanase 50.98 U/ml (4 days and 20.42 U/ml (4 days, respectivelyin synthetic medium containing carboxymethycellulose as a carbon source. When these 2 isolates were added into the steriled POMW under shaking condition for 7 days, after centrifugation at 3,184 xg the isolate SO1gave the better % reduction of dry weight (64.66 % and of oil and grease in the bottom layer (85.32 % of the POMW.