Functional characterization of GH7 endo-1,4-β-glucanase from Aspergillus fumigatus and its potential industrial application.

PubMed

Bernardi, Aline Vianna; de Gouvêa, Paula Fagundes; Gerolamo, Luis Eduardo; Yonamine, Deborah Kimie; de Lourdes de Lima Balico, Laís; Uyemura, Sergio Akira; Dinamarco, Taisa Magnani

2018-04-30

A gene encoding an endo-1,4-β-glucanase (Afu6g01800) from A. fumigatus was cloned into the vector pET-28a(+) and expressed in the E. coli strain RosettaTM (DE3) pLysS. Sequence analysis indicated that the enzyme Af-EGL7 belonged to the GH7 family. The gene Af-egl7 encoded a protein comprising 460 amino acids, with a CBM1 domain at residues 424-460 and molecular mass of 52 kDa, as estimated by SDS-PAGE. This enzyme was optimally active at pH and temperatures ranging from 4.5 to 5.5 and from 40 to 60 °C, respectively. Mn 2+ addition significantly enhanced the Af-EGL7 cellulase activity by 233%, whereas SDS addition fully inhibited this activity. Higher activity was observed toward β-glucan than toward xyloglucan and CM-Cellulose, suggesting that the enzyme corresponds to a β-1,3-1,4-glucanase. qRT-PCR in different culture media helped to establish the time-course expression profile. Different polysaccharides induced the gene Af-egl7 in a time-dependent manner; in the particular case of the substrate sugarcane exploded bagasse (SEB), Af-egl7 was induced 2500-fold. Upon addition to a commercial cellulase cocktail, Af-EGL7 significantly improved SEB saccharification, which suggested that the enzyme Af-EGL7 had great potential to hydrolyze complex biomass. From a biotechnological point of view, A. fumigatus Af-EGL7 is a promising candidate to enhance enzyme cocktails used in biorefineries such as consolidated bioprocessing. Copyright © 2018 Elsevier Inc. All rights reserved.

Engineering Cellulases for Biorefinery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Manoj

2010-06-27

Lignocellulosic biomass is the most abundant, least expensive renewable natural biological resource for the production of biobased products and bioenergy is important for the sustainable development of human civilization in 21st century. For making the fermentable sugars from lignocellulosic biomass, a reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for each cellulase component enzyme, as well as on the reconstitutionmore » of cellulase components. In this paper, we will provide DSM's efforts in cellulase research and developments and focus on limitations. Cellulase improvement strategies based on directed evolution using screening on relevant substrates, screening for higher thermal tolerance based on activity screening approaches such as continuous culture using insoluble cellulosic substrates as a powerful selection tool for enriching beneficial cellulase mutants from the large library. We will illustrate why and how thermostable cellulases are vital for economic delivery of bioproducts from cellulosic biomass using biochemical conversion approach.« less

Thermostable Cellulases: Why & How?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Manoj

2010-04-19

Lignocellulosic biomass is the most abundant, least expensive renewable natural biological resource for the production of biobased products and bioenergy is important for the sustainable development of human civilization in 21st century. For making the fermentable sugars from lignocellulosic biomass, a reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for each cellulase component enzyme, as well as on the reconstitutionmore » of cellulase components. In this paper, we will provide DSM's efforts in cellulase research and developments and focus on limitations. Cellulase improvement strategies based on directed evolution using screening on relevant substrates, screening for higher thermal tolerance based on activity screening approaches such as continuous culture using insoluble cellulosic substrates as a powerful selection tool for enriching beneficial cellulase mutants from the large library. We will illustrate why and how thermostable cellulases are vital for economic delivery of bioproducts from cellulosic biomass using biochemical conversion approach.« less

Trpac1, a pH response transcription regulator, is involved in cellulase gene expression in Trichoderma reesei.

PubMed

He, Ronglin; Ma, Lijuan; Li, Chen; Jia, Wendi; Li, Demao; Zhang, Dongyuan; Chen, Shulin

2014-12-01

Fungi grow over a relatively wide pH range and adapt to extracellular pH through a genetic regulatory system mediated by a key component PacC, which is a pH transcription regulator. The cellulase production of the filamentous fungi Trichoderma reesei is sensitive to ambient pH. To investigate the connection between cellulase expression regulation and ambient pH, an ortholog of Aspergillus nidulans pacC, Trpac1, was identified and functionally characterized using a target gene deletion strategy. Deleting Trpac1 dramatically increased the cellulase production and the transcription levels of the major cellulase genes at neutral pH, which suggested Trpac1 is involved in the regulation of cellulase production. It was further observed that the expression levels of transcription factors xyr1 and ace2 also increased in the ΔTrpac1 mutant at neutral pH. In addition, the ΔTrpac1 mutant exhibited conidiation defects under neutral and alkaline pH. These results implied that Trpac1 in involved in growth and development process and cellulase gene expression in T. reesei. Copyright © 2014 Elsevier Inc. All rights reserved.

Thermostable Cellulases: Why & How?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Manoj

2010-03-24

These are a set of slides from the conference. Lignocellulosic biomass is the most abundant, least expensive renewable natural biological resource for the production of biobased products and bioenergy is important for the sustainable development of human civilization in 21st century. For making the fermentable sugars from lignocellulosic biomass, a reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for eachmore » cellulase component enzyme, as well as on the reconstitution of cellulase components. In this paper, we will provide DSM's efforts in cellulase research and developments and focus on limitations. Cellulase improvement strategies based on directed evolution using screening on relevant substrates, screening for higher thermal tolerance based on activity screening approaches such as continuous culture using insoluble cellulosic substrates as a powerful selection tool for enriching beneficial cellulase mutants from the large library. We will illustrate why and how thermostable cellulases are vital for economic delivery of bioproducts from cellulosic biomass using biochemical conversion approach.« less

The C. elegans Hox gene egl-5 is required for correct development of the hermaphrodite hindgut and for the response to rectal infection by Microbacterium nematophilum.

PubMed

Nicholas, Hannah R; Hodgkin, Jonathan

2009-05-01

Members of the Hox gene family encode transcription factors that specify positional identity along the anterior-posterior axis of nearly all metazoans. One among the Caenorhabditis elegans Hox genes is egl-5. A deletion allele of egl-5 was isolated in a screen for animals which fail to develop swollen tails when exposed to the bacterial pathogen Microbacterium nematophilum. We show that compromised rectal development, which occurs as a result of loss of egl-5 function, results in a failure of rectal epithelial cells to express the ERK MAP kinase mpk-1, which was previously shown to mediate tail-swelling in response to bacterial infection. Tissue-specific rescue experiments demonstrated that egl-5 and mpk-1 act autonomously in rectal cells in the morphological response. The weak egl-5 allele (n1439), which does not compromise rectal development, fails to affect tail-swelling. We find that this allele carries an inserted repeat element approximately 13.8 kb upstream of the egl-5 open reading frame, which specifically disrupts the cell-specific expression of this gene in HSN egg-laying neurons. Together these findings extend the complexity of regulation and function of Hox genes in C. elegans and demonstrate the importance of their tissue-specific expression for correct development and response to infection.

Cellulases and coding sequences

DOEpatents

Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

2001-02-20

The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

Cellulases and coding sequences

DOEpatents

Li, Xin-Liang; Ljungdahl, Lars G.; Chen, Huizhong

2001-01-01

The present invention provides three fungal cellulases, their coding sequences, recombinant DNA molecules comprising the cellulase coding sequences, recombinant host cells and methods for producing same. The present cellulases are from Orpinomyces PC-2.

Aromatic amino acids in the cellulose binding domain of Penicillium crustosum endoglucanase EGL1 differentially contribute to the cellulose affinity of the enzyme

PubMed Central

Xiong, Wei; Chen, Fang-Yuan; Xu, Li; Han, Zheng-Gang

2017-01-01

The cellulose binding domain (CBD) of cellulase binding to cellulosic materials is the initiation of a synergistic action on the enzymatic hydrolysis of the most abundant renewable biomass resources in nature. The binding of the CBD domain to cellulosic substrates generally relies on the interaction between the aromatic amino acids structurally located on the flat face of the CBD domain and the glucose rings of cellulose. In this study, we found the CBD domain of a newly cloned Penicillium crustosum endoglucanase EGL1, which was phylogenetically related to Aspergillus, Fusarium and Rhizopus, and divergent from the well-characterized Trichoderma reeseis cellulase CBD domain, contain two conserved aromatic amino acid-rich regions, Y451-Y452 and Y477-Y478-Y479, among which three amino acids Y451, Y477, and Y478 structurally sited on a flat face of this domain. Cellulose binding assays with green fluorescence protein as the marker, adsorption isotherm assays and an isothermal titration calorimetry assays revealed that although these three amino acids participated in this process, the Y451-Y452 appears to contribute more to the cellulose binding than Y477-Y478-Y479. Further glycine scanning mutagenesis and structural modelling revealed that the binding between CBD domain and cellulosic materials might be multi-amino-acids that participated in this process. The flexible poly-glucose molecule could contact Y451, Y477, and Y478 which form the contacting flat face of CBD domain as the typical model, some other amino acids in or outside the flat face might also participate in the interaction. Thus, it is possible that the conserved Y451-Y452 of CBD might have a higher chance of contacting the cellulosic substrates, contributing more to the affinity of CBD than the other amino acids. PMID:28475645

Production, Optimization, and Characterization of Organic Solvent Tolerant Cellulases from a Lignocellulosic Waste-Degrading Actinobacterium, Promicromonospora sp. VP111.

PubMed

Thomas, Lebin; Ram, Hari; Kumar, Alok; Singh, Ved Pal

2016-07-01

High costs of natural cellulose utilization and cellulase production are an industrial challenge. In view of this, an isolated soil actinobacterium identified as Promicromonospora sp. VP111 showed potential for production of major cellulases (CMCase, FPase, and β-glucosidase) utilizing untreated agricultural lignocellulosic wastes. Extensive disintegration of microcrystalline cellulose and adherence on it during fermentation divulged true cellulolytic efficiency of the strain. Conventional optimization resulted in increased cellulase yield in a cost-effective medium, and the central composite design (CCD) analysis revealed cellulase production to be limited by cellulose and ammonium sulfate. Cellulase activities were enhanced by Co(+2) (1 mM) and retained up to 60 °C and pH 9.0, indicating thermo-alkaline tolerance. Cellulases showed stability in organic solvents (25 % v/v) with log P ow  ≥ 1.24. Untreated wheat straw during submerged fermentation was particularly degraded and yielded about twofold higher levels of cellulases than with commercial cellulose (Na-CMC and avicel) which is especially economical. Thus, this is the first detailed report on cellulases from an efficient strain of Promicromonospora that was non-hemolytic, alkali-halotolerant, antibiotic (erythromycin, kanamycin, rifampicin, cefaclor, ceftazidime) resistant, multiple heavy metal (Mo(+6) = W(+6) > Pb(+2) > Mn(+2) > Cr(+3) > Sn(+2)), and organic solvent (n-hexane, isooctane) tolerant, which is industrially and environmentally valuable.

Xylan extraction from pretreated sugarcane bagasse using alkaline and enzymatic approaches.

PubMed

Sporck, Daniele; Reinoso, Felipe A M; Rencoret, Jorge; Gutiérrez, Ana; Del Rio, José C; Ferraz, André; Milagres, Adriane M F

2017-01-01

New biorefinery concepts are necessary to drive industrial use of lignocellulose biomass components. Xylan recovery before enzymatic hydrolysis of the glucan component is a way to add value to the hemicellulose fraction, which can be used in papermaking, pharmaceutical, and food industries. Hemicellulose removal can also facilitate subsequent cellulolytic glucan hydrolysis. Sugarcane bagasse was pretreated with an alkaline-sulfite chemithermomechanical process to facilitate subsequent extraction of xylan by enzymatic or alkaline procedures. Alkaline extraction methods yielded 53% (w/w) xylan recovery. The enzymatic approach provided a limited yield of 22% (w/w) but produced the xylan with the lowest contamination with lignin and glucan components. All extracted xylans presented arabinosyl side groups and absence of acetylation. 2D-NMR data suggested the presence of O -methyl-glucuronic acid and p -coumarates only in enzymatically extracted xylan. Xylans isolated using the enzymatic approach resulted in products with molecular weights (Mw) lower than 6 kDa. Higher Mw values were detected in the alkali-isolated xylans. Alkaline extraction of xylan provided a glucan-enriched solid readily hydrolysable with low cellulase loads, generating hydrolysates with a high glucose/xylose ratio. Hemicellulose removal before enzymatic hydrolysis of the cellulosic fraction proved to be an efficient manner to add value to sugarcane bagasse biorefining. Xylans with varied yield, purity, and structure can be obtained according to the extraction method. Enzymatic extraction procedures produce high-purity xylans at low yield, whereas alkaline extraction methods provided higher xylan yields with more lignin and glucan contamination. When xylan extraction is performed with alkaline methods, the residual glucan-enriched solid seems suitable for glucose production employing low cellulase loadings.

Production of a cellulase-free alkaline xylanase from Bacillus pumilus MTCC 5015 by submerged fermentation and its application in biobleaching.

PubMed

Thomas, Leya; Sindhu, Raveendran; Binod, Parameswaran; Pandey, Ashok

2015-06-01

Here, we described the production of a cellulase-free alkaline xylanase from Bacillus pumilus MTCC 5015 by submerged fermentation and its application in biobleaching. Various process parameters affecting xylanase production by B. pumilus were optimized by adopting a Plackett-Burman design (PBD) as well as Response surface methodology (RSM). These statistical methods aid in improving the enzyme yield by analysing the individual crucial components of the medium. Maximum production was obtained with 4% yeast extract, 0.08% magnesium sulphate, 30 h of inoculum age, incubation temperature of 33.5 degrees C and pH 9.0. Under optimized conditions, the xylanase activity was 372 IU/ml. Media engineering improved a 5-fold increase in the enzyme production. Scanning electron microscopy (SEM) showed significant changes on the surface of xylanase treated pulps as a result of xylan hydrolysis. Increased roughness of paper carton fibres was apparent in scanning electron micrograph due to opening of the micro fibrils present on the surface by xylanase action. The untreated pulp did not show any such change. These results demonstrated that the B. pumilus MTCC 5015 xylanase was effective in bio-bleaching of paper carton.

Chimeric enzymes with improved cellulase activities

DOEpatents

Xu, Qi; Baker, John O; Himmel, Michael E

2015-03-31

Nucleic acid molecules encoding chimeric cellulase polypeptides that exhibit improved cellulase activities are disclosed herein. The chimeric cellulase polypeptides encoded by these nucleic acids and methods to produce the cellulases are also described, along with methods of using chimeric cellulases for the conversion of cellulose to sugars such as glucose.

The TcEG1 beetle (Tribolium castaneum) cellulase produced in transgenic switchgrass is active at alkaline pH and auto-hydrolyzes biomass for increased cellobiose release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Willis, Jonathan D.; Grant, Joshua N.; Mazarei, Mitra

Genetically engineered biofuel crops, such as switchgrass (Panicum virgatum L.), that produce their own cell wall-digesting cellulase enzymes would reduce costs of cellulosic biofuel production. To date, non-bioenergy plant models have been used in nearly all studies assessing the synthesis and activity of plant-produced fungal and bacterial cellulases. One potential source for cellulolytic enzyme genes is herbivorous insects adapted to digest plant cell walls. Here we examine the potential of transgenic switchgrass-produced TcEG1 cellulase from Tribolium castaneum (red flour beetle). This enzyme, when overproduced in Escherichia coli and Saccharomyces cerevisiae, efficiently digests cellulose at optima of 50 °C and pHmore » 12.0. TcEG1 that was produced in green transgenic switchgrass tissue had a range of endoglucanase activity of 0.16–0.05 units (µM glucose release/min/mg) at 50 °C and pH 12.0. TcEG1 activity from air-dried leaves was unchanged from that from green tissue, but when tissue was dried in a desiccant oven (46 °C), specific enzyme activity decreased by 60%. When transgenic biomass was “dropped-in” into an alkaline buffer (pH 12.0) and allowed to incubate at 50 °C, cellobiose release was increased up to 77% over non-transgenic biomass. Saccharification was increased in one transgenic event by 28%, which had a concurrent decrease in lignin content of 9%. Histological analysis revealed an increase in cell wall thickness with no change to cell area or perimeter. Transgenic plants produced more, albeit narrower, tillers with equivalent dry biomass as the control. This work describes the first study in which an insect cellulase has been produced in transgenic plants; in this case, the dedicated bioenergy crop switchgrass. Switchgrass overexpressing the TcEG1 gene appeared to be morphologically similar to its non-transgenic control and produced equivalent dry biomass. Therefore, we propose TcEG1 transgenics could be bred with other transgenic

The TcEG1 beetle (Tribolium castaneum) cellulase produced in transgenic switchgrass is active at alkaline pH and auto-hydrolyzes biomass for increased cellobiose release

DOE PAGES

Willis, Jonathan D.; Grant, Joshua N.; Mazarei, Mitra; ...

2017-11-30

Genetically engineered biofuel crops, such as switchgrass (Panicum virgatum L.), that produce their own cell wall-digesting cellulase enzymes would reduce costs of cellulosic biofuel production. To date, non-bioenergy plant models have been used in nearly all studies assessing the synthesis and activity of plant-produced fungal and bacterial cellulases. One potential source for cellulolytic enzyme genes is herbivorous insects adapted to digest plant cell walls. Here we examine the potential of transgenic switchgrass-produced TcEG1 cellulase from Tribolium castaneum (red flour beetle). This enzyme, when overproduced in Escherichia coli and Saccharomyces cerevisiae, efficiently digests cellulose at optima of 50 °C and pHmore » 12.0. TcEG1 that was produced in green transgenic switchgrass tissue had a range of endoglucanase activity of 0.16–0.05 units (µM glucose release/min/mg) at 50 °C and pH 12.0. TcEG1 activity from air-dried leaves was unchanged from that from green tissue, but when tissue was dried in a desiccant oven (46 °C), specific enzyme activity decreased by 60%. When transgenic biomass was “dropped-in” into an alkaline buffer (pH 12.0) and allowed to incubate at 50 °C, cellobiose release was increased up to 77% over non-transgenic biomass. Saccharification was increased in one transgenic event by 28%, which had a concurrent decrease in lignin content of 9%. Histological analysis revealed an increase in cell wall thickness with no change to cell area or perimeter. Transgenic plants produced more, albeit narrower, tillers with equivalent dry biomass as the control. This work describes the first study in which an insect cellulase has been produced in transgenic plants; in this case, the dedicated bioenergy crop switchgrass. Switchgrass overexpressing the TcEG1 gene appeared to be morphologically similar to its non-transgenic control and produced equivalent dry biomass. Therefore, we propose TcEG1 transgenics could be bred with other transgenic

Ionic liquid-tolerant cellulase enzymes

DOEpatents

Gladden, John; Park, Joshua; Singer, Steven; Simmons, Blake; Sale, Ken

2017-10-31

The present invention provides ionic liquid-tolerant cellulases and method of producing and using such cellulases. The cellulases of the invention are useful in saccharification reactions using ionic liquid treated biomass.

Enhanced enzymatic hydrolysis and ethanol production from cashew apple bagasse pretreated with alkaline hydrogen peroxide.

PubMed

da Costa, Jessyca Aline; Marques, José Edvan; Gonçalves, Luciana Rocha Barros; Rocha, Maria Valderez Ponte

2015-03-01

The effect of combinations and ratios between different enzymes has been investigated in order to assess the optimal conditions for hydrolysis of cashew apple bagasse pretreated with alkaline hydrogen peroxide (the solids named CAB-AHP). The separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes were evaluated in the ethanol production. The enzymatic hydrolysis conducted with cellulase complex and β-glucosidase in a ratio of 0.61:0.39, enzyme loading of 30FPU/g(CAB-AHP) and 66CBU/g(CAB-AHP), respectively, using 4% cellulose from CAB-AHP, turned out to be the most effective conditions, with glucose and xylose yields of 511.68 mg/g(CAB-AHP) and 237.8 mg/g(CAB-AHP), respectively. Fermentation of the pure hydrolysate by Kluyveromyces marxianus ATCC 36907 led to an ethanol yield of 61.8kg/ton(CAB), corresponding to 15 g/L ethanol and productivity of 3.75 g/( Lh). The ethanol production obtained for SSF process using K. marxianus ATCC 36907 was 18 g/L corresponding to 80% yield and 74.2kg/ton(CAB). Copyright © 2014 Elsevier Ltd. All rights reserved.

Exo-endo cellulase fusion protein

DOEpatents

Bower, Benjamin S [Palo Alto, CA; Larenas, Edmund A [Palo Alto, CA; Mitchinson, Colin [Palo Alto, CA

2012-01-17

The present invention relates to a heterologous exo-endo cellulase fusion construct, which encodes a fusion protein having cellulolytic activity comprising a catalytic domain derived from a fungal exo-cellobiohydrolase and a catalytic domain derived from an endoglucanase. The invention also relates to vectors and fungal host cells comprising the heterologous exo-endo cellulase fusion construct as well as methods for producing a cellulase fusion protein and enzymatic cellulase compositions.

Synergistic action of recombinant accessory hemicellulolytic and pectinolytic enzymes to Trichoderma reesei cellulase on rice straw degradation.

PubMed

Laothanachareon, Thanaporn; Bunterngsook, Benjarat; Suwannarangsee, Surisa; Eurwilaichitr, Lily; Champreda, Verawat

2015-12-01

Synergism between core cellulases and accessory hydrolytic/non-hydrolytic enzymes is the basis of efficient hydrolysis of lignocelluloses. In this study, the synergistic action of three recombinant accessory enzymes, namely GH62 α-l-arabinofuranosidase (ARA), CE8 pectin esterase (PET), and GH10 endo-1,4-beta-xylanase (XYL) from Aspergillus aculeatus expressed in Pichia pastoris to a commercial Trichoderma reesei cellulase (Accellerase® 1500; ACR) on hydrolysis of alkaline pretreated rice straw was studied using a mixture design approach. Applying the full cubic model, the optimal ratio of quaternary enzyme mixture was predicted to be ACR:ARA:PET:XYL of 0.171:0.079:0.100:0.150, which showed a glucose releasing efficiency of 0.173 gglc/FPU, higher than the binary ACR:XYL mixture (0.122 gglc/FPU) and ACR alone (0.081 gglc/FPU) leading to a 47.3% increase in glucose yield compared with that from ACR at the same cellulase dosage. The result demonstrates the varying degree of synergism of accessory enzymes to cellulases useful for developing tailor-made enzyme systems for bio-industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bioprospecting thermophiles for cellulase production: a review.

PubMed

Acharya, Somen; Chaudhary, Anita

2012-07-01

Most of the potential bioprospecting is currently related to the study of the extremophiles and their potential use in industrial processes. Recently microbial cellulases find applications in various industries and constitute a major group of industrial enzymes. Considerable amount of work has been done on microbial cellulases, especially with resurgence of interest in biomass ethanol production employing cellulases and use of cellulases in textile and paper industry. Most efficient method of lignocellulosic biomass hydrolysis is through enzymatic saccharification using cellulases. Significant information has also been gained about the physiology of thermophilic cellulases producers and process development for enzyme production and biomass saccharification. The review discusses the current knowledge on cellulase producing thermophilic microorganisms, their physiological adaptations and control of cellulase gene expression. It discusses the industrial applications of thermophilic cellulases, their cost of production and challenges in cellulase research especially in the area of improving process economics of enzyme production.

Bioprospecting thermophiles for cellulase production: a review

PubMed Central

Acharya, Somen; Chaudhary, Anita

2012-01-01

Most of the potential bioprospecting is currently related to the study of the extremophiles and their potential use in industrial processes. Recently microbial cellulases find applications in various industries and constitute a major group of industrial enzymes. Considerable amount of work has been done on microbial cellulases, especially with resurgence of interest in biomass ethanol production employing cellulases and use of cellulases in textile and paper industry. Most efficient method of lignocellulosic biomass hydrolysis is through enzymatic saccharification using cellulases. Significant information has also been gained about the physiology of thermophilic cellulases producers and process development for enzyme production and biomass saccharification. The review discusses the current knowledge on cellulase producing thermophilic microorganisms, their physiological adaptations and control of cellulase gene expression. It discusses the industrial applications of thermophilic cellulases, their cost of production and challenges in cellulase research especially in the area of improving process economics of enzyme production. PMID:24031898

C. elegans GATA factors EGL-18 and ELT-6 function downstream of Wnt signaling to maintain the progenitor fate during larval asymmetric divisions of the seam cells.

PubMed

Gorrepati, Lakshmi; Thompson, Kenneth W; Eisenmann, David M

2013-05-01

The C. elegans seam cells are lateral epithelial cells arrayed in a single line from anterior to posterior that divide in an asymmetric, stem cell-like manner during larval development. These asymmetric divisions are regulated by Wnt signaling; in most divisions, the posterior daughter in which the Wnt pathway is activated maintains the progenitor seam fate, while the anterior daughter in which the Wnt pathway is not activated adopts a differentiated hypodermal fate. Using mRNA tagging and microarray analysis, we identified the functionally redundant GATA factor genes egl-18 and elt-6 as Wnt pathway targets in the larval seam cells. EGL-18 and ELT-6 have previously been shown to be required for initial seam cell specification in the embryo. We show that in larval seam cell asymmetric divisions, EGL-18 is expressed strongly in the posterior seam-fated daughter. egl-18 and elt-6 are necessary for larval seam cell specification, and for hypodermal to seam cell fate transformations induced by ectopic Wnt pathway overactivation. The TCF homolog POP-1 binds a site in the egl-18 promoter in vitro, and this site is necessary for robust seam cell expression in vivo. Finally, larval overexpression of EGL-18 is sufficient to drive expression of a seam marker in other hypodermal cells in wild-type animals, and in anterior hypodermal-fated daughters in a Wnt pathway-sensitized background. These data suggest that two GATA factors that are required for seam cell specification in the embryo independently of Wnt signaling are reused downstream of Wnt signaling to maintain the progenitor fate during stem cell-like divisions in larval development.

C. elegans GATA factors EGL-18 and ELT-6 function downstream of Wnt signaling to maintain the progenitor fate during larval asymmetric divisions of the seam cells

PubMed Central

Gorrepati, Lakshmi; Thompson, Kenneth W.; Eisenmann, David M.

2013-01-01

The C. elegans seam cells are lateral epithelial cells arrayed in a single line from anterior to posterior that divide in an asymmetric, stem cell-like manner during larval development. These asymmetric divisions are regulated by Wnt signaling; in most divisions, the posterior daughter in which the Wnt pathway is activated maintains the progenitor seam fate, while the anterior daughter in which the Wnt pathway is not activated adopts a differentiated hypodermal fate. Using mRNA tagging and microarray analysis, we identified the functionally redundant GATA factor genes egl-18 and elt-6 as Wnt pathway targets in the larval seam cells. EGL-18 and ELT-6 have previously been shown to be required for initial seam cell specification in the embryo. We show that in larval seam cell asymmetric divisions, EGL-18 is expressed strongly in the posterior seam-fated daughter. egl-18 and elt-6 are necessary for larval seam cell specification, and for hypodermal to seam cell fate transformations induced by ectopic Wnt pathway overactivation. The TCF homolog POP-1 binds a site in the egl-18 promoter in vitro, and this site is necessary for robust seam cell expression in vivo. Finally, larval overexpression of EGL-18 is sufficient to drive expression of a seam marker in other hypodermal cells in wild-type animals, and in anterior hypodermal-fated daughters in a Wnt pathway-sensitized background. These data suggest that two GATA factors that are required for seam cell specification in the embryo independently of Wnt signaling are reused downstream of Wnt signaling to maintain the progenitor fate during stem cell-like divisions in larval development. PMID:23633508

Cellulase and cell differentiation in Acer pseudoplatanus.

PubMed

Sheldrake, A R

1970-06-01

Homogenates of differentiating xylem and phloem tissue have higher cellulase activities than cambial samples; the highest activity is always found in phloem. Callus tissue, in which no vascular differentiation occurs, contains only low cellulase activity. The results suggest that cellulase is involved in vascular differentiation. Different pH optima of cellulase activity were found: in cambium, xylem and phloem tissue, cellulase activity with an optimum at about pH 5.9 is predominantly membrane-bound; it is sedimentable at 100,000 g and releasable by Triton X-100. The same may be true of activity with an optimum at pH 5.3. Phloem tissue also contains a soluble, cytoplasmic cellulase of high activity at pH 7.1, and xylem tissue contains cytoplasmic cellulase with an optimum at pH 6.5. Low cellulase activity with a pH optimum similar to that of xylem homogenates was found in xylem sap. Cellulase activity in abscission zones increases greatly just before leaf abscission. Abscission zone cellulase has two pH optima, et 5.3 and 5.9; both activities are increased by Triton treatment of homogenates. The possible existence of several different cellulases forming part of a cellulase complex, and the rôle of the enzymes in hydrolysing wall material during cell differentiation are discussed.

Highly Efficient Thermostable DSM Cellulases: Why & How?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kumar, Manoj

2011-04-26

These are the slides from this presentation. Lignocellulosic biomass is the most abundant, least expensive renewable natural biological resource for the production of biobased products and bioenergy is important for the sustainable development of human civilization in 21st century. For making the fermentable sugars from lignocellulosic biomass, a reduction in cellulase production cost, an improvement in cellulase performance, and an increase in sugar yields are all vital to reduce the processing costs of biorefineries. Improvements in specific cellulase activities for non-complexed cellulase mixtures can be implemented through cellulase engineering based on rational design or directed evolution for each cellulase componentmore » enzyme, as well as on the reconstitution of cellulase components. In this paper, we will provide DSM's efforts in cellulase research and developments and focus on limitations. Cellulase improvement strategies based on directed evolution using screening on relevant substrates, screening for higher thermal tolerance based on activity screening approaches such as continuous culture using insoluble cellulosic substrates as a powerful selection tool for enriching beneficial cellulase mutants from the large library. We will illustrate why and how thermostable cellulases are vital for economic delivery of bioproducts from cellulosic biomass using biochemical conversion approach.« less

Effect of glucose and cellulase addition on wet-storage of excessively wilted maize stover and biogas production.

PubMed

Guo, Jianbin; Cui, Xian; Sun, Hui; Zhao, Qian; Wen, Xiaoyu; Pang, Changle; Dong, Renjie

2018-07-01

In north China, large amounts of excessively wilted maize stover are produced annually. Maize stover wet storage strategies and subsequent biogas production was examined in this study. Firstly, wet storage performances of harvested maize stover, air-dried for different time durations, were evaluated. Results showed that optimal storage performance was obtained when the initial water soluble carbohydrate (WSC) content after air-drying was higher than 8.0%. Therefore, cellulase and glucose were added to the excessively wilted maize stover to achieve the targeted pre-storage WSC levels. Good storage performances were observed in treatments with addition of 76.4 g/kg DM glucose and 12.5 g/kg DM of cellulase; the specific methane yield increased by 23.7% and 19.2%, respectively. However, use of glucose as additive or co-storing with high WSC substrates can serve as economically feasible options to adapt wet storage of excessively wilted maize stover. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ultrasonic hyperactivation of cellulase immobilized on magnetic nanoparticles.

PubMed

Ladole, Mayur Ramrao; Mevada, Jayesh Sevantilal; Pandit, Aniruddha Bhalchandra

2017-09-01

In the present work, effect of low power, low frequency ultrasound on cellulase immobilized magnetic nanoparticles (cellulase@MNPs) was studied. To gain maximum activity recovery in cellulase@MNPs various parameters viz. ratio of MNPs:cellulase, concentration of glutaraldehyde and cross-linking time were optimized. The influence of ultrasonic power on cellulase@MNPs was studied. Under ultrasonic conditions at 24kHz, 6W power, and 6min of incubation time there was almost 3.6 fold increased in the catalytic activity of immobilized cellulase over the control. Results also indicated that there was improvement in pH and temperature stability of cellulase@MNPs. Furthermore, thermal deactivation energy required was more in cellulase@MNPs than that of the free cellulase. Secondary structural analysis revealed that there were conformational changes in free cellulase and cellulase@MNPs before and after sonication which might be responsible for enhanced activity after ultrasonication. Finally, the influence of ultrasound and cellulase@MNPs for biomass hydrolysis was studied. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biochemistry and genetics of actinomycete cellulases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wilson, D.B.

1992-01-01

The order Actinomycetales includes a number of genera that contain species that actively degrade cellulose and these include both mesophilic and facultative thermophilic species. Cellulases produced by strains from two of the genera containing thermophilic organisms have been studied extensively: Microbispora bispora and Thermomonospora fusca. Fractionation of M. bispora cellulases has identified six different enzymes, all of which were purified to near homogeneity and partially characterized. Two of these enzymes appear to be exocellulases and gave synergism with each other and with the endocellulases. The structural genes of five M. bispora cellulases have been cloned and one was sequenced. Fractionationmore » of T. fusca cellulases has identified five different enzymes, all of which were purified to near homogeneity and partially characterized. One of the T. fusca enzymes gives synergism in the hydrolysis of crystalline cellulose with several T. fusca endocellulases and with Trichoderma reesei CBHI but not with T. reesei CBHII. Each T. fusca cellulase contains distinct catalytic and cellulose binding domains. The structural genes of four of the T. fusca endoglucanases have been cloned and sequenced, while three cellulase genes have been cloned from T. curvata. The T. fusca cellulase genes are expressed at a low level in Escherichia coli, but at a high level in Streptomyces lividans. Sequence comparisons have shown that there are no significant amino acid homologies between any of the catalytic domains of the four T. fusca cellulases, but each of them shows extensive homology to several other cellulases and fits in one of the five existing cellulase gene families. 73 refs., 8 figs., 4 tabs.« less

Microbial Cellulases and Their Industrial Applications

PubMed Central

Kuhad, Ramesh Chander; Gupta, Rishi; Singh, Ajay

2011-01-01

Microbial cellulases have shown their potential application in various industries including pulp and paper, textile, laundry, biofuel production, food and feed industry, brewing, and agriculture. Due to the complexity of enzyme system and immense industrial potential, cellulases have been a potential candidate for research by both the academic and industrial research groups. Nowadays, significant attentions have been devoted to the current knowledge of cellulase production and the challenges in cellulase research especially in the direction of improving the process economics of various industries. Scientific and technological developments and the future prospects for application of cellulases in different industries are discussed in this paper. PMID:21912738

Thermostable cellulase from a thermomonospora gene

DOEpatents

Wilson, David B.; Walker, Larry P.; Zhang, Sheng

1997-10-14

The invention relates to a gene isolated from Thermomonospora fusca, wherein the gene encodes a thermostable cellulase. Disclosed is the nucleotide sequence of the T. fusca gene; and nucleic acid molecules comprising the gene, or a fragment of the gene, that can be used to recombinantly express the cellulase or a catalytically active polypeptide thereof, respectively. The isolated and purified recombinant cellulase or catalytically active polypeptide may be used to hydrolyze substrate either by itself; or in combination with other cellulases, with the resultant combination having unexpected hydrolytic activity.

Thermostable cellulase from a thermomonospora gene

DOEpatents

Wilson, D.B.; Walker, L.P.; Zhang, S.

1997-10-14

The invention relates to a gene isolated from Thermomonospora fusca, wherein the gene encodes a thermostable cellulase. Disclosed is the nucleotide sequence of the T. fusca gene; and nucleic acid molecules comprising the gene, or a fragment of the gene, that can be used to recombinantly express the cellulase or a catalytically active polypeptide thereof, respectively. The isolated and purified recombinant cellulase or catalytically active polypeptide may be used to hydrolyze substrate either by itself; or in combination with other cellulases, with the resultant combination having unexpected hydrolytic activity. 3 figs.

[Biodiversity and enzymes of culturable facultative-alkaliphilic actinobacteria in saline-alkaline soil in Fukang, Xinjiang].

PubMed

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.

Reaction mechanism of dicofol removal by cellulase.

PubMed

Wang, Ziyuan; Yang, Ting; Zhai, Zihan; Zhang, Boya; Zhang, Jianbo

2015-10-01

It remains unclear whether dicofol should be defined as a persistent organic pollutant. Its environmental persistence has gained attention. This study focused on its degradation by cellulase. Cellulase was separated using a gel chromatogram, and its degradation activity towards dicofol involved its endoglucanase activity. By analyzing the kinetic parameters of cellulase reacting with mixed substrates, it was shown that cellulase reacted on dicofol and carboxyl methyl cellulose through two different active centers. Thus, the degradation of dicofol was shown to be an oxidative process by cellulase. Next, by comparing the impacts of tert-butyl alcohol (a typical OH free-radical inhibitor) on the removal efficiencies of dicofol under both cellulase and Fenton reagent systems, it was shown that the removal of dicofol was initiated by OH free radicals produced by cellulase. Finally, 4,4'-dichloro-dibenzophenone and chloride were detected using gas chromatography mass spectrometry and ion chromatography analysis, which supported our hypothesis. The reaction mechanism was analyzed and involved an attack by OH free radicals at the orthocarbon of dicofol, resulting in the degradation product 4,4'-dichloro-dibenzophenone. Copyright © 2015. Published by Elsevier B.V.

Undefined cellulase formulations hinder scientific reproducibility

DOE PAGES

Himmel, Michael E.; Abbas, Charles A.; Baker, John O.; ...

2017-11-28

In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparationsmore » may not be available. Therefore, being a critical tenet of science publishing, experimental reproducibility is endangered by the continued use of these undisclosed products. We propose the introduction of standard procedures and materials to produce specific and reproducible cellulase formulations. These formulations are to serve as yardsticks to measure improvements and performance of new cellulase formulations.« less

Undefined cellulase formulations hinder scientific reproducibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Himmel, Michael E.; Abbas, Charles A.; Baker, John O.

In the shadow of a burgeoning biomass-to-fuels industry, biological conversion of lignocellulose to fermentable sugars in a cost-effective manner is key to the success of second-generation and advanced biofuel production. For the effective comparison of one cellulase preparation to another, cellulase assays are typically carried out with one or more engineered cellulase formulations or natural exoproteomes of known performance serving as positive controls. When these formulations have unknown composition, as is the case with several widely used commercial products, it becomes impossible to compare or reproduce work done today to work done in the future, where, for example, such preparationsmore » may not be available. Therefore, being a critical tenet of science publishing, experimental reproducibility is endangered by the continued use of these undisclosed products. We propose the introduction of standard procedures and materials to produce specific and reproducible cellulase formulations. These formulations are to serve as yardsticks to measure improvements and performance of new cellulase formulations.« less

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

PubMed

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.

Enhanced cellulose degradation using cellulase-nanosphere complexes.

PubMed

Blanchette, Craig; Lacayo, Catherine I; Fischer, Nicholas O; Hwang, Mona; Thelen, Michael P

2012-01-01

Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS) and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC); however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production.

Enhanced Cellulose Degradation Using Cellulase-Nanosphere Complexes

PubMed Central

Blanchette, Craig; Lacayo, Catherine I.; Fischer, Nicholas O.; Hwang, Mona; Thelen, Michael P.

2012-01-01

Enzyme catalyzed conversion of plant biomass to sugars is an inherently inefficient process, and one of the major factors limiting economical biofuel production. This is due to the physical barrier presented by polymers in plant cell walls, including semi-crystalline cellulose, to soluble enzyme accessibility. In contrast to the enzymes currently used in industry, bacterial cellulosomes organize cellulases and other proteins in a scaffold structure, and are highly efficient in degrading cellulose. To mimic this clustered assembly of enzymes, we conjugated cellulase obtained from Trichoderma viride to polystyrene nanospheres (cellulase:NS) and tested the hydrolytic activity of this complex on cellulose substrates from purified and natural sources. Cellulase:NS and free cellulase were equally active on soluble carboxymethyl cellulose (CMC); however, the complexed enzyme displayed a higher affinity in its action on microcrystalline cellulose. Similarly, we found that the cellulase:NS complex was more efficient in degrading natural cellulose structures in the thickened walls of cultured wood cells. These results suggest that nanoparticle-bound enzymes can improve catalytic efficiency on physically intractable substrates. We discuss the potential for further enhancement of cellulose degradation by physically clustering combinations of different glycosyl hydrolase enzymes, and applications for using cellulase:NS complexes in biofuel production. PMID:22870287

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

PubMed

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.

Enhanced cellulase production by Penicillium oxalicum for bio-ethanol application.

PubMed

Saini, Reetu; Saini, Jitendra Kumar; Adsul, Mukund; Patel, Anil Kumar; Mathur, Anshu; Tuli, Deepak; Singhania, Reeta Rani

2015-01-01

Present study was focused on cellulase production from an indigenously isolated filamentous fungal strain, identified as Penicillium oxalicum. Initially, cellulase production under submerged fermentation in shake flasks resulted in cellulase activity of 0.7 FPU/mL. Optimization of process parameters enhanced cellulase production by 1.7-fold and resulted in maximum cellulase activity of 1.2 FPU/mL in 8 days. Cellulase production was successfully scaled-up to 7 L fermenter under controlled conditions and incubation time was reduced from 8 days to 4 days for achieving similar cellulase titer. Optimum pH and temperature for activity of the crude enzyme were pH 5 and 50 °C, respectively. At 50 °C the produced cellulase retained approximately 50% and 26% of its activity at 48 h and 72 h, respectively. Hydrolytic efficiency of P. oxalicum was comparable to commercial cellulase preparations which indicate its great potential for application in the lignocellulose hydrolysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Characterization of a thermophilic cellulase from Geobacillus sp. HTA426, an efficient cellulase-producer on alkali pretreated of lignocellulosic biomass.

PubMed

Potprommanee, Laddawan; Wang, Xiao-Qin; Han, Ye-Ju; Nyobe, Didonc; Peng, Yen-Ping; Huang, Qing; Liu, Jing-Yong; Liao, Yu-Ling; Chang, Ken-Lin

2017-01-01

A themophilic cellulase-producing bacterium was isolated from a hot spring district and identified as Geobacillus sp. HTA426. The cellulase enzyme produced by the Geobacillus sp. HTA426 was purified through ammonium sulfate precipitation and ion exchange chromatography, with the recovery yield and fold purification of 10.14% and 5.12, respectively. The purified cellulase has a molecular weight of 40 kDa. The optimum temperature and pH for carboxymethyl cellulase (CMCase) activity of the purified cellulase were 60°C and pH 7.0, respectively. The enzyme was also stable over a wide temperature range of 50°C to 70°C after 5 h of incubation. Moreover, the strain HTA426 was able to grow and produce cellulase on alkali-treated sugarcane bagasse, rice straw and water hyacinth as carbon sources. Enzymatic hydrolysis of sugarcane bagasse, which was regarded as the most effective carbon source for cellulase production (CMCase activity = 103.67 U/mL), followed by rice straw (74.70 U/mL) and water hyacinth (51.10 U/mL). This strain producing an efficient thermostable cellulose is a potential candidate for developing a more efficient and cost-effective process for converting lignocellulosic biomass into biofuel and other industrial process.

Characterization of a thermophilic cellulase from Geobacillus sp. HTA426, an efficient cellulase-producer on alkali pretreated of lignocellulosic biomass

PubMed Central

Potprommanee, Laddawan; Wang, Xiao-Qin; Han, Ye-Ju; Nyobe, Didonc; Peng, Yen-Ping; Huang, Qing; Liu, Jing-yong; Liao, Yu-Ling; Chang, Ken-Lin

2017-01-01

A themophilic cellulase-producing bacterium was isolated from a hot spring district and identified as Geobacillus sp. HTA426. The cellulase enzyme produced by the Geobacillus sp. HTA426 was purified through ammonium sulfate precipitation and ion exchange chromatography, with the recovery yield and fold purification of 10.14% and 5.12, respectively. The purified cellulase has a molecular weight of 40 kDa. The optimum temperature and pH for carboxymethyl cellulase (CMCase) activity of the purified cellulase were 60°C and pH 7.0, respectively. The enzyme was also stable over a wide temperature range of 50°C to 70°C after 5 h of incubation. Moreover, the strain HTA426 was able to grow and produce cellulase on alkali-treated sugarcane bagasse, rice straw and water hyacinth as carbon sources. Enzymatic hydrolysis of sugarcane bagasse, which was regarded as the most effective carbon source for cellulase production (CMCase activity = 103.67 U/mL), followed by rice straw (74.70 U/mL) and water hyacinth (51.10 U/mL). This strain producing an efficient thermostable cellulose is a potential candidate for developing a more efficient and cost-effective process for converting lignocellulosic biomass into biofuel and other industrial process. PMID:28406925

Increase in stability of cellulase immobilized on functionalized magnetic nanospheres

NASA Astrophysics Data System (ADS)

Zhang, Wenjuan; Qiu, Jianhui; Feng, Huixia; Zang, Limin; Sakai, Eiichi

2015-02-01

Functionalized magnetic nanospheres were prepared by co-condensation of tetraethylorthosilicate with three different amino-silanes: 3-(2-aminoethylamino propyl)-triethoxysilane (AEAPTES), 3-(2-aminoethylamino propyl)-trimethoxysilane (AEAPTMES) and 3-aminopropyltriethoxysilane (APTES). Then three functionalized magnetic nanospheres were used as supports for immobilization of cellulase. The three functionalized magnetic nanospheres with core-shell morphologies exhibited higher capacity for cellulase immobilization than unfunctionalized magnetic nanospheres. The increasing of surface charge of functionalized magnetic nanospheres leads to an enhancement of the capacity of cellulase immobilization. Particularly, AEAPTMES with methoxy groups was favored to be hydrolyzed and grafted on unfunctionalized magnetic nanospheres than the others. AEAPTMES functionalized magnetic nanospheres with the highest zeta potential (29 mV) exhibited 87% activity recovery and the maximum amount of immobilized cellulase was 112 mg/g support at concentration of initial cellulase of 8 mg/mL. Immobilized cellulase on AEAPTMES functionalized magnetic nanospheres had higher temperature stability and broader pH stability than other immobilized cellulases and free cellulase. In particular, it can be used in about 40 °C, demonstrating the potential of biofuel production using this immobilized cellulase.

49 CFR 237.1 - Application.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Application. 237.1 Section 237.1 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS General § 237.1 Application. (a) Except as provided in paragraphs (b) or...

40 CFR 745.237 - Inspections.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Inspections. 745.237 Section 745.237 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.237...

40 CFR 745.237 - Inspections.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Inspections. 745.237 Section 745.237 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.237...

40 CFR 745.237 - Inspections.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Inspections. 745.237 Section 745.237 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.237...

40 CFR 745.237 - Inspections.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Inspections. 745.237 Section 745.237 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.237...

40 CFR 745.237 - Inspections.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Inspections. 745.237 Section 745.237 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) TOXIC SUBSTANCES CONTROL ACT LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Lead-Based Paint Activities § 745.237...

Comparative evaluation of acid and alkaline sulfite pretreatments for enzymatic saccharification of bagasses from three different sugarcane hybrids.

PubMed

Monte, Joseana R; Laurito-Friend, Debora F; Ferraz, André; Milagres, Adriane M F

2018-04-26

Sugarcane bagasses from three experimental sugarcane hybrids and a mill-reference sample were used to compare the efficiency and mode of action of acid and alkaline sulfite pretreatment processes. Varied chemical loads and reaction temperatures were used to prepare samples with distinguished characteristics regarding xylan and lignin removals, as well as sulfonation levels of residual lignins. The pretreatment with low sulfite loads (5%) under acidic conditions (pH 2) provided maximum glucose yield of 70% during enzymatic hydrolysis with cellulases (10 FPU/g) and β-glucosidases (20 UI/g bagasse). In this case, glucan enzymatic conversion from pretreated materials was mostly associated with extensive xylan removal (70-100%) and partial delignification occurred during the pretreatment. The use of low sulfite loads under acidic conditions required pretreatment temperatures of 160°C. In contrast, at a lower pretreatment temperature (120°C), alkaline sulfite process achieved similar glucan digestibility, but required a higher sulfite load (7.5%). Residual xylans from acid pretreated materials were almost completely hydrolysed by commercial enzymes, contrasting with relatively lower xylan to xylose conversions observed in alkaline pretreated samples. Efficient xylan removal during acid sulfite pretreatment and also during enzymatic digestion can be useful to enhance glucan accessibility and digestibility by cellulases. Alkaline sulfite process also provided substrates with high glucan digestibility, mainly associated with delignification and sulfonation of residual lignins. The results demonstrate that temperature, pH and sulfite can be combined for reducing lignocellulose recalcitrance and achieve similar glucan conversion rates in the alkaline and acid sulfite pretreated bagasses. This article is protected by copyright. All rights reserved. © 2018 American Institute of Chemical Engineers.

Production of cellulase from Pestalotiopsis versicolor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, M.N.A.; Mithal, B.M.; Thakur, R.N.

1983-01-01

Production of cellulase from Pestalotiopsis versicolor was studied in a shake flask culture. The cellulase system was found to be rich in beta-glucosidase. Kinetic parameters such as pH and temperature have been optimized for the various enzyme components. 9 references.

Optimization of Cellulase Production from Bacteria Isolated from Soil

PubMed Central

Sethi, Sonia; Datta, Aparna; Gupta, B. Lal; Gupta, Saksham

2013-01-01

Cellulase-producing bacteria were isolated from soil and identified as Pseudomonas fluorescens, Bacillus subtilIs, E. coli, and Serratia marcescens. Optimization of the fermentation medium for maximum cellulase production was carried out. The culture conditions like pH, temperature, carbon sources, and nitrogen sources were optimized. The optimum conditions found for cellulase production were 40°C at pH 10 with glucose as carbon source and ammonium sulphate as nitrogen source, and coconut cake stimulates the production of cellulase. Among bacteria, Pseudomonas fluorescens is the best cellulase producer among the four followed by Bacillus subtilis, E. coli, and Serratia marscens. PMID:25937986

Exploring surface characterization and electrostatic property of Hybrid Pennisetum during alkaline sulfite pretreatment for enhanced enzymatic hydrolysability.

PubMed

Yang, Ming; Wang, Jingfeng; Hou, Xincun; Wu, Juying; Fan, Xifeng; Jiang, Fan; Tao, Pan; Wang, Fan; Peng, Pai; Yang, Fangxia; Zhang, Junhua

2017-11-01

The surface characterization and electrostatic property of Hybrid Pennisetum (HP) after alkaline sulfite pretreatment were explored for enhanced enzymatic hydrolysability. The O/C ratio in HP increased from 0.34 to 0.60, and C1 concentration decreased from 62.5% to 31.6%, indicating that alkaline sulfite pretreatment caused poorer lignin but richer carbohydrate on HP surface. Zeta potential and sulfur element analysis indicated that more enzymes would preferably adsorb on the carbohydrate surface of alkaline sulfite pretreated HP because the lignin was sulfonated, which facilitated the decrease of non-productive adsorption. Glucose yield of alkaline sulfite pretreated HP reached to 100% by synergistic action of cellulase and xylanase in the hydrolysis, which was significantly higher than that of NaOH pretreated, and the concentration of glucose released was 1.52times higher. The results suggested that alkaline sulfite pretreatment had potential for improving the HP hydrolysability, and the surface characterization and electrostatic property facilitated the enzymatic digestibility. Copyright © 2017 Elsevier Ltd. All rights reserved.

48 CFR 237.102 - Policy.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Policy. 237.102 Section 237.102 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING Service Contracts-General 237.102 Policy. (c) In addition to the prohibition on award of...

49 CFR 237.131 - Design.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Design. 237.131 Section 237.131 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS Repair and Modification of Bridges § 237.131 Design. Each repair or... component of a bridge shall be designed by a railroad bridge engineer. The design shall specify the manner...

High-throughput selection for cellulase catalysts using chemical complementation.

PubMed

Peralta-Yahya, Pamela; Carter, Brian T; Lin, Hening; Tao, Haiyan; Cornish, Virginia W

2008-12-24

Efficient enzymatic hydrolysis of lignocellulosic material remains one of the major bottlenecks to cost-effective conversion of biomass to ethanol. Improvement of glycosylhydrolases, however, is limited by existing medium-throughput screening technologies. Here, we report the first high-throughput selection for cellulase catalysts. This selection was developed by adapting chemical complementation to provide a growth assay for bond cleavage reactions. First, a URA3 counter selection was adapted to link chemical dimerizer activated gene transcription to cell death. Next, the URA3 counter selection was shown to detect cellulase activity based on cleavage of a tetrasaccharide chemical dimerizer substrate and decrease in expression of the toxic URA3 reporter. Finally, the utility of the cellulase selection was assessed by isolating cellulases with improved activity from a cellulase library created by family DNA shuffling. This application provides further evidence that chemical complementation can be readily adapted to detect different enzymatic activities for important chemical transformations for which no natural selection exists. Because of the large number of enzyme variants that selections can now test as compared to existing medium-throughput screens for cellulases, this assay has the potential to impact the discovery of improved cellulases and other glycosylhydrolases for biomass conversion from libraries of cellulases created by mutagenesis or obtained from natural biodiversity.

Cytochemical localization of cellulases in decayed and nondecayed wood

DOE Office of Scientific and Technical Information (OSTI.GOV)

Murmanis, L.; Highley, T.L.; Palmer, J.G.

1987-01-01

Sawdust from undecayed western hemlock wood and from wood previously decayed by the brown-rot fungus Poria placenta or by the white-rot fungus Ganoderma applanatum was incubated with commercial cellulase from Trichoderma viride. Samples were treated cytochemically to locate cellulase activity and examined by TEM. Results showed that cellulase degraded undecayed wood extensively, with the attack starting on the outer border of a cell wall and progressing inside. Wood decayed by P. placenta, with or without cellulase incubation, and treated by the cytochemical test showed uniform distribution of electron dense particles throughout the cell walls. In wood decayed by G. applanatum,more » cellulase degradation was similar to that in undecayed wood. From measurements of particle diameter it is suggested that electron dense particles are cellulase. It is concluded that brown-rot and white-rot fungi have different effects on the microstructure of wood. The brown-rot fungus appears to open the wood microstructure so that cellulase can diffuse throughout the degraded tracheid wall.« less

49 CFR 237.7 - Penalties.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Penalties. 237.7 Section 237.7 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS General § 237.7 Penalties. (a) Any person who violates any requirement of this part or causes the violation of any such requirement is subject to a civil penalty of at least...

49 CFR 237.7 - Penalties.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Penalties. 237.7 Section 237.7 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS General § 237.7 Penalties. (a) Any person who violates any requirement of this part or causes the violation of any such requirement is subject to a civil penalty of at least...

49 CFR 237.7 - Penalties.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Penalties. 237.7 Section 237.7 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS General § 237.7 Penalties. (a) Any person who violates any requirement of this part or causes the violation of any such requirement is subject to a civil penalty of at least...

49 CFR 237.7 - Penalties.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Penalties. 237.7 Section 237.7 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS General § 237.7 Penalties. (a) Any person who violates any requirement of this part or causes the violation of any such requirement is subject to a civil penalty of at least...

49 CFR 237.7 - Penalties.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Penalties. 237.7 Section 237.7 Transportation... TRANSPORTATION BRIDGE SAFETY STANDARDS General § 237.7 Penalties. (a) Any person who violates any requirement of this part or causes the violation of any such requirement is subject to a civil penalty of at least...

Hydrolysis of lignocelluloses by penicillium funiculosum cellulase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mishra, C.; Rao, M.; Seeta, R.

1984-04-01

Enzymatic hydrolysis of cellulose is a promising method for the conversion of waste cellulose to glucose. During the past few years, the development of this technology has proceeded rapidly, with significant advances made in enzyme production, pretreatment, and hydrolysis. A variety of fungi are reported to produce cellulases but among these Trichoderma reesei and its mutants are powerful producers of cellulases. However, the search for new and possibly better sources of cellulase is continued due to the low levels of beta-glucosidase of T. reesei. Penicillium funiculosum produces a complete cellulase having endo-beta-1,4-glucanase (15-20 U/mL), exo-beta-1,4-glucanase (1.5-2.0 U/mL), and high beta-glucosidasemore » (8-10 U/mL). The saccharification of alkali-treated cotton and bagasse by P. funiculosum enzyme was 70 and 63%, respectively. It was possible to obtain glucose concentration as high as 30% using 50% bagasse. It is of interest that the percent saccharification of cellulosic substrates with the Penicillium enzyme is comparable to that of T. reesei cellulase when the same amount of filter paper activity is used, although the endo-glucanase activity of the latter is two to three times higher. This communication reports the studies on saccharification of lignocelluloses by P. funiculosum cellulase and certain studies on the kinetic aspects. (Refs. 15).« less

Cloning of cellulase genes from acidothermus cellulolyticus

DOEpatents

Lastick, deceased, Stanley M.; Tucker, Melvin P.; Grohmann, Karel

1996-01-01

A process is described for moving fragments that code for cellulase activity from the genome of A. cellulolyticus to several plasmid vectors and the subsequent expression of active cellulase acitivty in E. coli.

Pulsed laser deposition and characterization of cellulase thin films

NASA Astrophysics Data System (ADS)

Cicco, N.; Morone, A.; Verrastro, M.; Viggiano, V.

2013-08-01

Thin films of cellulase were obtained by pulsed laser deposition (PLD) on an appropriate substrate. Glycoside hydrolase cellulase has received our attention because it emerges among the antifouling enzymes (enzymes being able to remove and prevent the formation of micro-organism biofilms) used in industry and medicine field. Pressed cellulase pellets, used as target material, were ablated with pulses of a Nd-YAG laser working at wavelength of 532 nm. In this work, we evaluated the impact of PLD technique both on molecular structure and hydrolytic activity of cellulase. Characteristic chemical bonds and morphology of deposited layers were investigated by FTIR spectroscopy and SEM respectively. The hydrolytic activity of cellulase thin films was detected by a colorimetric assay.

Cloning of cellulase genes from Acidothermus cellulolyticus

DOEpatents

Lastick, S.M.; Tucker, M.P.; Grohmann, K.

1996-05-07

A process is described for moving fragments that code for cellulase activity from the genome of A. cellulolyticus to several plasmid vectors and the subsequent expression of active cellulase activity in E. coli. 5 figs.

The effect of lignin removal by alkaline peroxide pretreatment on the susceptibility of corn stover to purified cellulolytic and xylanolytic enzymes.

PubMed

Selig, Michael J; Vinzant, Todd B; Himmel, Michael E; Decker, Stephen R

2009-05-01

Pretreatment of corn stover with alkaline peroxide (AP) at pH 11.5 resulted in reduction of lignin content in the residual solids as a function of increasing batch temperature. Scanning electron microscopy of these materials revealed notably more textured surfaces on the plant cell walls as a result of the delignifying pretreatment. As expected, digestion of the delignified samples with commercial cellulase preparations showed an inverse relationship between the content of lignin present in the residual solids after pretreatment and the extent of both glucan and xylan conversion achievable. Digestions with purified enzymes revealed that decreased lignin content in the pretreated solids did not significantly impact the extent of glucan conversion achievable by cellulases alone. Not until purified xylanolytic activities were included with the cellulases were significant improvements in glucan conversion realized. In addition, an inverse relationship was observed between lignin content after pretreatment and the extent of xylan conversion achievable in a 24-h period with the xylanolytic enzymes in the absence of the cellulases. This observation, coupled with the direct relationship between enzymatic xylan and glucan conversion observed in a number of cases, suggests that the presence of lignins may not directly occlude cellulose present in lignocelluloses but rather impact cellulase action indirectly by its association with xylan.

21 CFR 184.1250 - Cellulase enzyme preparation derived from Trichoderma longibrachiatum.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Cellulase enzyme preparation derived from....1250 Cellulase enzyme preparation derived from Trichoderma longibrachiatum. (a) Cellulase enzyme.... reesei). The enzyme, cellulase, catalyzes the endohydrolysis of 1,4-beta-glycosidic linkages in cellulose...

21 CFR 184.1250 - Cellulase enzyme preparation derived from Trichoderma longibrachiatum.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Cellulase enzyme preparation derived from....1250 Cellulase enzyme preparation derived from Trichoderma longibrachiatum. (a) Cellulase enzyme.... reesei). The enzyme, cellulase, catalyzes the endohydrolysis of 1,4-beta-glycosidic linkages in cellulose...

21 CFR 184.1250 - Cellulase enzyme preparation derived from Trichoderma longibrachiatum.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Cellulase enzyme preparation derived from....1250 Cellulase enzyme preparation derived from Trichoderma longibrachiatum. (a) Cellulase enzyme.... reesei). The enzyme, cellulase, catalyzes the endohydrolysis of 1,4-beta-glycosidic linkages in cellulose...

21 CFR 184.1250 - Cellulase enzyme preparation derived from Trichoderma longibrachiatum.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Cellulase enzyme preparation derived from....1250 Cellulase enzyme preparation derived from Trichoderma longibrachiatum. (a) Cellulase enzyme.... reesei). The enzyme, cellulase, catalyzes the endohydrolysis of 1,4-beta-glycosidic linkages in cellulose...

Cellulase variants with improved expression, activity and stability, and use thereof

DOEpatents

Aehle, Wolfgang; Bott, Richard R; Bower, Benjamin; Caspi, Jonathan; Estell, David A; Goedegebuur, Frits; Hommes, Ronaldus W.J.; Kaper, Thijs; Kelemen, Bradley; Kralj, Slavko; Van Lieshout, Johan; Nikolaev, Igor; Van Stigt Thans, Sander; Wallace, Louise; Vogtentanz, Gudrun; Sandgren, Mats

2014-03-25

The present disclosure relates to cellulase variants. In particular the present disclosure relates to cellulase variants having improved expression, activity and/or stability. Also described are nucleic acids encoding the cellulase variants, compositions comprising the cellulase variants, and methods of use thereof.

Cellulase variants with improved expression, activity and stability, and use thereof

DOEpatents

Aehle, Wolfgang; Bott, Richard R.; Bower, Benjamin S.; Caspi, Jonathan; Goedegebuur, Frits; Hommes, Ronaldus Wilhelmus Joannes; Kaper, Thijs; Kelemen, Bradley R.; Kralj, Slavko; Van Lieshout, Johannes Franciscus Thomas; Nikolaev, Igor; Wallace, Louise; Van Stigt Thans, Sander; Vogtentanz, Gudrun; Sandgren, Mats

2016-12-20

The present disclosure relates to cellulase variants. In particular the present disclosure relates to cellulase variants having improved expression, activity and/or stability. Also described are nucleic acids encoding the cellulase variants, compositions comprising the cellulase variants, and methods of use thereof.

Approaches for improving thermostability characteristics in cellulases.

PubMed

Anbar, Michael; Bayer, Edward A

2012-01-01

Many efforts have been invested to reduce the cost of biofuel production to substitute renewable sources of energy for fossil-based fuels. At the forefront of these efforts are the initiatives to convert plant-derived cellulosic material to biofuels. Although significant improvements have been achieved recently in cellulase engineering in both efficiency and cost reduction, complete degradation of lignocellulosic material still requires very long periods of time and high enzyme loads. Thermostable cellulases offer many advantages in the bioconversion process, which include increase in specific activity, higher levels of stability, inhibition of microbial growth, increase in mass transfer rate due to lower fluid viscosity, and greater flexibility in the bioprocess. Besides rational design methods, which require deep understanding of protein structure-function relationship, two of the major methods for improvement in specific cellulase properties are directed evolution and knowledge-based library design based on multiple sequence alignments. In this chapter, we provide protocols for constructing and screening of improved thermostable cellulases. Modifications of these protocols may also be used for screening for other improved properties of cellulases such as pH tolerance, high salt, and more. Copyright © 2012 Elsevier Inc. All rights reserved.

Enhanced Production of Trichoderma reesei Endoglucanases and Use of the New Cellulase Preparations in Producing the Stonewashed Effect on Denim Fabric

PubMed Central

Miettinen-Oinonen, Arja; Suominen, Pirkko

2002-01-01

Trichoderma reesei strains were constructed for production of elevated amounts of endoglucanase II (EGII) with or without cellobiohydrolase I (CBHI). The endoglucanase activity produced by the EGII transformants correlated with the copy number of the egl2 expression cassette. One copy of the egl2 expression cassette in which the egl2 was under the cbh1 promoter increased production of endoglucanase activity 2.3-fold, and two copies increased production about 3-fold above that of the parent strain. When the enzyme with elevated EGII content was used, an improved stonewashing effect on denim fabric was achieved. A T. reesei strain producing high amounts of EGI and -II activities without CBHI and -II was constructed by replacing the cbh2 locus with the coding region of the egl2 gene in the EGI-overproducing CBHI-negative strain. Production of endoglucanase activity by the EG-transformant strain was increased fourfold above that of the host strain. The filter paper-degrading activity of the endoglucanase-overproducing strain was lowered to below detection, presumably because of the lack of cellobiohydrolases. PMID:12147496

A High-throughput Selection for Cellulase Catalysts Using Chemical Complementation

PubMed Central

Peralta-Yahya, Pamela; Carter, Brian T.; Lin, Hening; Tao, Haiyan; Cornish, Virginia W.

2010-01-01

Efficient enzymatic hydrolysis of lignocellulosic material remains one of the major bottlenecks to cost-effective conversion of biomass to ethanol. Improvement of glycosylhydrolases however is limited by existing medium-throughput screening technologies. Here, we report the first high-throughput selection for cellulase catalysts. This selection was developed by adapting chemical complementation to provide a growth assay for bond cleavage reactions. First, a URA3 counter selection was adapted to link chemical dimerizer activated gene transcription to cell death. Next, the URA3 counter selection was shown to detect cellulase activity based on cleavage of a tetrasaccharide chemical dimerizer substrate and decrease in expression of the toxic URA3 reporter. Finally, the utility of the cellulase selection was assessed by isolating cellulases with improved activity from a cellulase library created by family DNA shuffling. This application provides further evidence that chemical complementation can be readily adapted to detect different enzymatic activities for important chemical transformations for which no natural selection exists. Due to the large number of enzyme variants selections can test compared to existing medium-throughput screens for cellulases, this assay has the potential to impact the discovery of improved cellulases and other glycosylhydrolases for biomass conversion from libraries of cellulases created by mutagenesis or obtained from natural biodiversity. PMID:19053460

46 CFR 169.237 - Inspection standards.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 7 2011-10-01 2011-10-01 false Inspection standards. 169.237 Section 169.237 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Inspections § 169.237 Inspection standards. Vessels are inspected for compliance...

46 CFR 169.237 - Inspection standards.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 7 2010-10-01 2010-10-01 false Inspection standards. 169.237 Section 169.237 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Inspection and Certification Inspections § 169.237 Inspection standards. Vessels are inspected for compliance...

Thermal tolerant cellulase from Acidothermus cellulolyticus

DOEpatents

Ding, Shi-You; Adney, William S.; Vinzant, Todd B.; Himmel, Michael E.; Decker, Stephen R.

2006-06-13

The invention provides a thermal tolerant cellulase that is a member of the glycoside hydrolase family. The invention further discloses this cellulase as GuxA. GuxA has been isolated and characterized from Acidothermus cellulolyticus. The invention further provides recombinant forms of the identified GuxA. Methods of making and using GuxA polypeptides, including fusions, variants, and derivatives, are also disclosed.

Thermal Tolerant Cellulase from Acidothermus Cellulolyticus

DOEpatents

Ding, S. Y.; Adney, W. S.; Vinzant, T. B.; Himmel, M. E.; Decker, S. R.

2006-06-13

The invention provides a thermal tolerant cellulase that is a member of the glycoside hydrolase family. The invention further discloses this cellulase as GuxA. GuxA has been isolated and characterized from Acidothermus cellulolyticus. The invention further provides recombinant forms of the identified GuxA. Methods of making and using GuxA polypeptides, including fusions, variants, and derivatives, are also disclosed.

49 CFR 237.151 - Audits; general.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Audits; general. 237.151 Section 237.151..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Documentation, Records, and Audits of Bridge Management Programs § 237.151 Audits; general. Each program adopted to comply with this part shall include provisions...

Lignin triggers irreversible cellulase loss during pretreated lignocellulosic biomass saccharification.

PubMed

Gao, Dahai; Haarmeyer, Carolyn; Balan, Venkatesh; Whitehead, Timothy A; Dale, Bruce E; Chundawat, Shishir Ps

2014-01-01

Non-productive binding of enzymes to lignin is thought to impede the saccharification efficiency of pretreated lignocellulosic biomass to fermentable sugars. Due to a lack of suitable analytical techniques that track binding of individual enzymes within complex protein mixtures and the difficulty in distinguishing the contribution of productive (binding to specific glycans) versus non-productive (binding to lignin) binding of cellulases to lignocellulose, there is currently a poor understanding of individual enzyme adsorption to lignin during the time course of pretreated biomass saccharification. In this study, we have utilized an FPLC (fast protein liquid chromatography)-based methodology to quantify free Trichoderma reesei cellulases (namely CBH I, CBH II, and EG I) concentration within a complex hydrolyzate mixture during the varying time course of biomass saccharification. Three pretreated corn stover (CS) samples were included in this study: Ammonia Fiber Expansion(a) (AFEX™-CS), dilute acid (DA-CS), and ionic liquid (IL-CS) pretreatments. The relative fraction of bound individual cellulases varied depending not only on the pretreated biomass type (and lignin abundance) but also on the type of cellulase. Acid pretreated biomass had the highest levels of non-recoverable cellulases, while ionic liquid pretreated biomass had the highest overall cellulase recovery. CBH II has the lowest thermal stability among the three T. reesei cellulases tested. By preparing recombinant family 1 carbohydrate binding module (CBM) fusion proteins, we have shown that family 1 CBMs are highly implicated in the non-productive binding of full-length T. reesei cellulases to lignin. Our findings aid in further understanding the complex mechanisms of non-productive binding of cellulases to pretreated lignocellulosic biomass. Developing optimized pretreatment processes with reduced or modified lignin content to minimize non-productive enzyme binding or engineering pretreatment

[Induction and regulation of cellulase expression in filamentous fungi: a review].

PubMed

Zhang, Fei; Bai, Fengwu; Zhao, Xinqing

2016-11-25

Production of bioenergy and bio-based chemicals by using fermentable sugars released from low-cost renewable lignocellulosic biomass has received great attention. Efficient cellulolytic enzymes are crucial for lignocellulose bioconversion, but high cellulase production cost is limiting the bioconversion efficiency of cellulosic biomass and industrial applications of lignocellulose biorefinery. Studies on induction and regulation of cellulase in filamentous fungi will help to further develop superior fungal strains for efficient cellulase production and reduce cellulase production cost. With the advances in high-throughput sequencing and gene manipulation technology using fungal strains, an in-depth understanding of cellulase induction and regulation mechanisms of enzyme expression has been achieved. We reviewed recent progresses in the induction and regulation of cellulase expression in several model filamentous fungi, emphasizing sugar transporters, transcription factors and chromatin remodeling. Future prospects in application of artificial zinc finger proteins for cellulase induction and regulation in filamentous fungi were discussed.

48 CFR 252.237-7003 - Requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Requirements. 252.237-7003... Clauses 252.237-7003 Requirements. As prescribed in 237.7003(b), use the following clause: Requirements... from the Contractor all of its requirements in the area of performance for the supplies and services...

48 CFR 252.237-7003 - Requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Requirements. 252.237-7003... Clauses 252.237-7003 Requirements. As prescribed in 237.7003(b), use the following clause: Requirements... from the Contractor all of its requirements in the area of performance for the supplies and services...

48 CFR 252.237-7003 - Requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Requirements. 252.237-7003... Clauses 252.237-7003 Requirements. As prescribed in 237.7003(b), use the following clause: Requirements... from the Contractor all of its requirements in the area of performance for the supplies and services...

48 CFR 252.237-7003 - Requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Requirements. 252.237-7003... Clauses 252.237-7003 Requirements. As prescribed in 237.7003(b), use the following clause: Requirements... from the Contractor all of its requirements in the area of performance for the supplies and services...

14 CFR 25.237 - Wind velocities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wind velocities. 25.237 Section 25.237... STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 25.237 Wind... wind velocity, demonstrated to be safe for takeoff and landing, must be established for dry runways and...

14 CFR 25.237 - Wind velocities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Wind velocities. 25.237 Section 25.237... STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 25.237 Wind... wind velocity, demonstrated to be safe for takeoff and landing, must be established for dry runways and...

14 CFR 25.237 - Wind velocities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wind velocities. 25.237 Section 25.237... STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 25.237 Wind... wind velocity, demonstrated to be safe for takeoff and landing, must be established for dry runways and...

7 CFR 959.237 - Assessment rate.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Assessment rate. 959.237 Section 959.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Assessment Rates § 959.237 Assessment rate. On and after August 1, 2012, an assessment rate of $0.03 per 50...

7 CFR 959.237 - Assessment rate.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Assessment rate. 959.237 Section 959.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 959.237 Assessment rate. On and after August 1, 2009, an assessment rate of $0.025 per 50...

7 CFR 959.237 - Assessment rate.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Assessment rate. 959.237 Section 959.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS... Assessment Rates § 959.237 Assessment rate. On and after August 1, 2009, an assessment rate of $0.025 per 50...

7 CFR 959.237 - Assessment rate.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 8 2010-01-01 2010-01-01 false Assessment rate. 959.237 Section 959.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 959.237 Assessment rate. On and after August 1, 2009, an assessment rate of $0.025 per 50...

7 CFR 959.237 - Assessment rate.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 8 2011-01-01 2011-01-01 false Assessment rate. 959.237 Section 959.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing Agreements... Assessment Rates § 959.237 Assessment rate. On and after August 1, 2009, an assessment rate of $0.025 per 50...

49 CFR 238.237 - Automated monitoring.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Automated monitoring. 238.237 Section 238.237... Equipment § 238.237 Automated monitoring. (a) Except as further specified in this paragraph, on or after... train speed and capabilities of the signal system. The railroad shall document the basis for setting...

14 CFR 25.237 - Wind velocities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wind velocities. 25.237 Section 25.237... STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 25.237 Wind... wind velocity, demonstrated to be safe for takeoff and landing, must be established for dry runways and...

14 CFR 25.237 - Wind velocities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wind velocities. 25.237 Section 25.237... STANDARDS: TRANSPORT CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 25.237 Wind... wind velocity, demonstrated to be safe for takeoff and landing, must be established for dry runways and...

32 CFR 237a.2 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 2 2010-07-01 2010-07-01 false Applicability. 237a.2 Section 237a.2 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS PUBLIC AFFAIRS LIAISON WITH INDUSTRY § 237a.2 Applicability. The provisions of this part apply to all...

Processing of cellulosic material by a cellulase-containing cell-free fermentate produced from cellulase-producing bacteria, ATCC 55702

DOEpatents

Dees, H. Craig

1998-01-01

Bacteria which produce large amounts of a cellulase-containing cell-free fermentate, have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase degrading bacterium ATCC 55702, which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic materials.

49 CFR 23.7 - Program reviews.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 1 2010-10-01 2010-10-01 false Program reviews. 23.7 Section 23.7 Transportation... CONCESSIONS General § 23.7 Program reviews. In 2010, and thereafter at the discretion of the Secretary, the Department will initiate a review of the ACDBE program to determine what, if any, modifications should be...

Intercalation of cellulase enzyme into a hydrotalcite layer structure

NASA Astrophysics Data System (ADS)

Zou, N.; Plank, J.

2015-01-01

A new inorganic-organic hybrid material whereby cellulase enzyme is incorporated into a hydrotalcite type layered double hydroxide (LDH) structure is reported. The Mg2Al-cellulase-LDH was synthesized via co-precipitation from Mg/Al nitrate at pH=9.6. Characterization was performed using X-ray powder diffraction (XRD), small angle X-ray scattering (SAXS), elemental analysis, infrared spectroscopy (IR) and thermogravimetry (TG). From XRD and SAXS measurements, a d-value of ~5.0 nm was identified for the basal spacing of the Mg2Al-cellulase-LDH. Consequently, the cellulase enzyme (hydrodynamic diameter ~6.6 nm) attains a slightly compressed conformation when intercalated. Formation of the LDH hybrid was also confirmed via scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Mg2Al-cellulase-LDH phases appear as ~20 nm thin foils which are intergrown to flower-like aggregates. Activity of the enzyme was retained after deintercalation from the Mg2Al-LDH framework using anion exchange. Accordingly, cellulase is not denatured during the intercalation process, and LDH presents a suitable host structure for time-controlled release of the biomolecule.

Processing of cellulosic material by a cellulase-containing cell-free fermentate produced from cellulase-producing bacteria, ATCC 55702

DOEpatents

Dees, H.C.

1998-08-04

Bacteria which produce large amounts of a cellulase-containing cell-free fermentate, have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase degrading bacterium ATCC 55702, which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic materials. 5 figs.

Compatible ionic liquid-cellulases system for hydrolysis of lignocellulosic biomass.

PubMed

Wang, Ying; Radosevich, Mark; Hayes, Douglas; Labbé, Nicole

2011-05-01

Ionic liquids (ILs) have been increasingly recognized as novel solvents for dissolution and pretreatment of cellulose. However, cellulases are inactivated in the presence of ILs, even when present at low concentrations. To more fully exploit the benefits of ILs it is critical to develop a compatible IL-cellulases system in which the IL is able to effectively solubilize and activate the lignocellulosic biomass, and the cellulases possess high stability and activity. In this study, we investigated the stability and activity of a commercially available cellulases mixture in the presence of different concentrations of 1-ethyl-3-methylimidazolium acetate ([Emim][OAc]). A mixture of cellulases and β-glucosidase (Celluclast1.5L, from Trichoderma reesei, and Novozyme188, from Aspergillus niger, respectively) retained 77% and 65% of its original activity after being pre-incubated in 15% and 20% (w/v) IL solutions, respectively, at 50°C for 3 h. The cellulases mixture also retained high activity in 15% [Emim][OAc] to hydrolyze Avicel, a model substrate for cellulose analysis, with conversion efficiency of approximately 91%. Notably, the presence of different amounts of yellow poplar lignin did not interfere significantly with the enzymatic hydrolysis of Avicel. Using this IL-cellulase system (15% [Emim][OAc]), the saccharification of yellow poplar biomass was also significantly improved (33%) compared to the untreated control (3%) during the first hour of enzymatic hydrolysis. Together, these findings provide compelling evidence that [Emim][OAc] was compatible with the cellulase mixture, and this compatible IL-cellulases system is promising for efficient activation and hydrolysis of native biomass to produce biofuels and co-products from the individual biomass components. Copyright © 2010 Wiley Periodicals, Inc.

Cellulase producing microorganism ATCC 55702

DOEpatents

Dees, H. Craig

1997-01-01

Bacteria which produce large amounts of cellulase--containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualifies for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques.

Cellulase producing microorganism ATCC 55702

DOEpatents

Dees, H.C.

1997-12-30

Bacteria which produce large amounts of cellulase--containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualifies for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques. 5 figs.

Enhanced production and application of acidothermophilic Streptomyces cellulase.

PubMed

Budihal, Saikumar R; Agsar, Dayanand; Patil, Sarvamangala R

2016-01-01

An efficient cellulolytic and acidothermophilic actinobacterium was isolated from soil, adhered to decomposing tree bark and was identified as Streptomyces DSK59. Screening of synthetic media and the media components identified that, a medium based on starch casein minerals containing carboxy methyl cellulose (CMC) and beef extract (BE) could support enhanced cellulase production by the organism. CMC, BE, NaCl, temperature and pH were accounted as significant for cellulase production and these were optimized using a response surface central composite design (CCD). Optimization of cellulase production resulted in an enhancement of endoglucanase activity to 27IUml(-1). Acidothermophillic Streptomyces cellulase was found to be efficient for hydrolysis of pretreated sorghum stover and liberated 0.413gg(-1) of total reducing sugars which was higher than previously reported sugar yields obtained using fungal enzymes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Insights into the effect of dilute acid, hot water or alkaline pretreatment on cellulose accessible surface area and the overall porosity of Populus

DOE PAGES

Meng, Xianzhi; Wells, Tyrone; Sun, Qining; ...

2015-06-19

Pretreatment is known to render biomass more reactive to cellulase by altering the chemical compositions as well as physical structures of biomass. Simons stain technique along with mercury porosimetry were applied on the acid, neutral, and alkaline pretreated materials to measure the accessible surface area of cellulose and pore size distribution of Populus. Results indicated that acid pretreatment is much more effective than water and alkaline pretreatment in terms of cellulose accessibility increase. Further investigation suggests that lignin does not dictate cellulose accessibility to the extent that hemicellulose does, but it does restrict xylan accessibility which in turn controls themore » access of cellulase to cellulose. The most interesting finding is that severe acid pretreatment significantly decreases the average pore size, i.e., 90% average size decrease could be observed after 60 min dilute acid pretreatment at 160 °C; moreover, the nano-pore space formed between coated microfibrils is increased after pretreatment, especially for the acid pretreatment, suggesting this particular type of biomass porosity is probably the most fundamental barrier to effective enzymatic hydrolysis.« less

7 CFR 1209.237 - Appointment.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 10 2013-01-01 2013-01-01 false Appointment. 1209.237 Section 1209.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE MUSHROOM PROMOTION, RESEARCH, AND...

7 CFR 1209.237 - Appointment.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 10 2014-01-01 2014-01-01 false Appointment. 1209.237 Section 1209.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE MUSHROOM PROMOTION, RESEARCH, AND...

7 CFR 1209.237 - Appointment.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Appointment. 1209.237 Section 1209.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE MUSHROOM PROMOTION, RESEARCH, AND...

7 CFR 1209.237 - Appointment.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 10 2012-01-01 2012-01-01 false Appointment. 1209.237 Section 1209.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE MUSHROOM PROMOTION, RESEARCH, AND...

7 CFR 1209.237 - Appointment.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 7 Agriculture 10 2011-01-01 2011-01-01 false Appointment. 1209.237 Section 1209.237 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE MUSHROOM PROMOTION, RESEARCH, AND...

Secretion of clostridium cellulase by E. coli

DOEpatents

Yu, Ida Kuo

1998-01-01

A gene, encoding an endocellulase from a newly isolated mesophilic Clostridium strain IY-2 which can digest bamboo fibers, cellulose, rice straw, and sawdust, was isolated by shotgun cloning in an E. coli expression plasmid pLC2833. E. coli positive clones were selected based on their ability to hydrolyze milled bamboo fibers and cellulose present in agar plates. One clone contained a 2.8 kb DNA fragment that was responsible for cellulase activity. Western blot analyses indicated that the positive clone produced a secreted cellulase with a mass of about 58,000 daltons that was identical in size to the subunit of one of the three major Clostridium cellulases. The products of cellulose digestion by this cloned cellulase were cellotetraose and soluble higher polymers. The cloned DNA contained signal sequences capable of directing the secretion of heterologous proteins from an E. coli host. The invention describes a bioprocess for the treatment of cellulosic plant materials to produce cellular growth substrates and fermentation end products suitable for production of liquid fuels, solvents, and acids.

Production Of Cellulase In Plastids Of Transgenic Plants

DOEpatents

Lamppa, Gayle

2002-08-06

A genetic construct encoding a fusion protein including endogluconase E1 and a transit peptide is used to transform plants. The plants produce cellulase by expressing the genetic construct. The cellulase is targeted to plastids and can be collected and purified.

Strong cellulase inhibition by Mannan polysaccharides in cellulose conversion to sugars.

PubMed

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.

Properties of cellulase as template molecule on chitosan—methyl methacrylate membrane

NASA Astrophysics Data System (ADS)

Lian, Qi; Zheng, Xuefang; Wu, Haixia; Song, Shitao; Wang, Dongjun

2015-12-01

In this study, a novel molecular imprinting membrane made of chitosan and methyl methacrylate (MMA) was fabricated with cellulase as template molecule and the thermal response to cellulase was characterized. The film was characterized by infrared spectroscopy (IR), X-ray diffraction (XRD), scanning electron microscopy (SEM) and the permeation experiment. The results showed that the space structure of the film was as similar as the cellulase. Moreover, the membrane had advanced molecular imprinting capability to cellulase comparing to pepsin and pectinase at any temperature and the film had excellent ability to identify specific template molecule (cellulase) at the synthesis temperature compared to other temperatures.

48 CFR 237.7202 - Limitations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Limitations. 237.7202 Section 237.7202 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT... funds for tuition or other expenses for training in any legal profession, except in connection with the...

48 CFR 237.7301 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... granting educational institution that— (1) Is located in the United States or its outlying areas; (2) Has... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Definitions. 237.7301 Section 237.7301 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT...

48 CFR 237.172 - Service Contracts Surveillance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Surveillance. 237.172 Section 237.172 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS...-General 237.172 Service Contracts Surveillance. Ensure that quality assurance surveillance plans are....) Retain quality assurance surveillance plans in the official contract file. See https://sam.dau.mil, Step...

48 CFR 237.172 - Service Contracts Surveillance.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Surveillance. 237.172 Section 237.172 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS...-General 237.172 Service Contracts Surveillance. Ensure that quality assurance surveillance plans are....) Retain quality assurance surveillance plans in the official contract file. See https://sam.dau.mil, Step...

48 CFR 237.172 - Service Contracts Surveillance.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Surveillance. 237.172 Section 237.172 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS...-General 237.172 Service Contracts Surveillance. Ensure that quality assurance surveillance plans are....) Retain quality assurance surveillance plans in the official contract file. See https://sam.dau.mil, Step...

48 CFR 237.172 - Service Contracts Surveillance.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Surveillance. 237.172 Section 237.172 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS...-General 237.172 Service Contracts Surveillance. Ensure that quality assurance surveillance plans are....) Retain quality assurance surveillance plans in the official contract file. See https://sam.dau.mil, Step...

48 CFR 237.172 - Service Contracts Surveillance.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Surveillance. 237.172 Section 237.172 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS...-General 237.172 Service Contracts Surveillance. Ensure that quality assurance surveillance plans are....) Retain quality assurance surveillance plans in the official contract file. See https://sam.dau.mil, Step...

21 CFR 173.120 - Carbohydrase and cellulase derived from Aspergillus niger.

Code of Federal Regulations, 2013 CFR

2013-04-01

... PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.120 Carbohydrase and cellulase derived from Aspergillus niger. Carbohydrase and cellulase enzyme preparation derived from... Aspergillus niger from the carbohydrase and cellulase enzyme product. (d) The additive is used or intended for...

21 CFR 184.1250 - Cellulase enzyme preparation derived from Trichoderma longibrachiatum.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Cellulase enzyme preparation derived from... SAFE Listing of Specific Substances Affirmed as GRAS § 184.1250 Cellulase enzyme preparation derived from Trichoderma longibrachiatum. (a) Cellulase enzyme preparation is derived from a nonpathogenic...

21 CFR 173.120 - Carbohydrase and cellulase derived from Aspergillus niger.

Code of Federal Regulations, 2012 CFR

2012-04-01

... PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.120 Carbohydrase and cellulase derived from Aspergillus niger. Carbohydrase and cellulase enzyme preparation derived from... Aspergillus niger from the carbohydrase and cellulase enzyme product. (d) The additive is used or intended for...

21 CFR 173.120 - Carbohydrase and cellulase derived from Aspergillus niger.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Enzyme Preparations and Microorganisms § 173.120 Carbohydrase and cellulase derived from Aspergillus niger. Carbohydrase and cellulase enzyme preparation derived from Aspergillus niger may be safely used... the carbohydrase and cellulase enzyme product. (d) The additive is used or intended for use as follows...

21 CFR 173.120 - Carbohydrase and cellulase derived from Aspergillus niger.

Code of Federal Regulations, 2011 CFR

2011-04-01

... PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.120 Carbohydrase and cellulase derived from Aspergillus niger. Carbohydrase and cellulase enzyme preparation derived from... Aspergillus niger from the carbohydrase and cellulase enzyme product. (d) The additive is used or intended for...

21 CFR 173.120 - Carbohydrase and cellulase derived from Aspergillus niger.

Code of Federal Regulations, 2010 CFR

2010-04-01

... PERMITTED IN FOOD FOR HUMAN CONSUMPTION Enzyme Preparations and Microorganisms § 173.120 Carbohydrase and cellulase derived from Aspergillus niger. Carbohydrase and cellulase enzyme preparation derived from... Aspergillus niger from the carbohydrase and cellulase enzyme product. (d) The additive is used or intended for...

49 CFR 237.103 - Bridge inspection procedures.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Bridge inspection procedures. 237.103 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection procedures. (a) Each bridge management program shall specify the procedure to be used for...

49 CFR 237.57 - Designations of individuals.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Designations of individuals. 237.57 Section 237.57... § 237.57 Designations of individuals. Each track owner shall designate those individuals qualified as railroad bridge engineers, railroad bridge inspectors and railroad bridge supervisors. Each individual...

49 CFR 237.103 - Bridge inspection procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Bridge inspection procedures. 237.103 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.103 Bridge inspection procedures. (a) Each bridge management program shall specify the procedure to be used for...

Cationic polyacrylamide enhancing cellulase treatment efficiency of hardwood kraft-based dissolving pulp.

PubMed

Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ni, Yonghao

2015-05-01

Cellulase treatment for decreasing viscosity and increasing Fock reactivity of dissolving pulp is a promising approach to reduce the use of toxic chemicals, such as hypochlorite in the dissolving pulp manufacturing process in the industry. Improving the cellulase treatment efficiency during the process is of practical interest. In the present study, the concept of using cationic polyacrylamide (CPAM) to enhance the cellulase treatment efficiency was demonstrated. This was mainly attributed to the increased cellulase adsorption onto cellulose fibers based on the patching/bridging mechanism. Results showed that the cellulase adsorption was increased by about 20% with the addition of 250 ppm of CPAM under the same conditions as those of the control. It was found that the viscosity decrease and Fock reactivity increase for the cellulase treatment was enhanced from using CPAM. The CPAM-assisted cellulase treatment concept may provide a practical alternative to the present hypochlorite-based technology for viscosity control in the industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Optimization of pretreatment and fermentation conditions for production of extracellular cellulase complex using sugarcane bagasse.

PubMed

Ashfaque, Mohammad; Solomon, Sushil; Pathak, Neelam

2014-01-01

Sugarcane bagasse (SCB), a lignocellulosic byproduct of juice extraction from sugarcane, is rich in cellulose (40-42%). This could be used as a substrate for the production of cellulase complex. Fermentation conditions were optimized for production of cellulase complex (CMCase, Cellulobiase and FPase) by wild type Trichoderma sp. using sugarcane bagasse as sole carbon source. Alkaline treatment (2% NaOH) of bagasse (AlSCB) was found suitable for the production of reducing sugar over the acidic pretreatment method. After 5 days of incubation period, 5% substrate concentration at pH 5.0 and 400C resulted in maximum production of CMCase (0.622 U), while maximum (3.388 U) production of cellulobiase was obtained at 300C. The CMCase was precipitated and purified to the extent of 59.06 fold by affinity chromatography with 49.09% recovery. On 12% SDS-PAGE, a single band corresponding to 33 kDa was observed. The Km and Vmax for CMCase from Trichoderma was found 507.04 mg/ml and 65.32 mM/min, respectively. The enzyme exhibited maximum activity at 300C at pH-5.0 (0.363 U) and was stable over range of 20-60°C and pH 5.0-7.5.

Aerobic and anaerobic cellulase production by Cellulomonas uda.

PubMed

Poulsen, Henrik Vestergaard; Willink, Fillip Wolfgang; Ingvorsen, Kjeld

2016-10-01

Cellulomonas uda (DSM 20108/ATCC 21399) is one of the few described cellulolytic facultative anaerobes. Based on these characteristics, we initiated a physiological study of C. uda with the aim to exploit it for cellulase production in simple bioreactors with no or sporadic aeration. Growth, cellulase activity and fermentation product formation were evaluated in different media under both aerobic and anaerobic conditions and in experiments where C. uda was exposed to alternating aerobic/anaerobic growth conditions. Here we show that C. uda behaves as a true facultative anaerobe when cultivated on soluble substrates such as glucose and cellobiose, but for reasons unknown cellulase activity is only induced under aerobic conditions on insoluble cellulosic substrates and not under anaerobic conditions. These findings enhance knowledge on the limited number of described facultative cellulolytic anaerobes, and in addition it greatly limits the utility of C. uda as an 'easy to handle' cellulase producer with low aeration demands.

Importance of cellulase cocktails favoring hydrolysis of cellulose.

PubMed

Victoria, Juliet; Odaneth, Annamma; Lali, Arvind

2017-07-03

Depolymerization of lignocellulosic biomass is catalyzed by groups of enzymes whose action is influenced by substrate features and the composition of cellulase preparation. Cellulases contain a mixture of variety of enzymes, whose proportions dictate the saccharification of biomass. In the current study, four cellulase preparation varying in their composition were used to hydrolyze two types of alkali-treated biomass (aqueous ammonia-treated rice straw and sodium hydroxide-treated rice straw) to study the effect on catalytic rate, saccharification yields, and sugar release profile. We found that substrate features affected the extent of saccharification but had minimal effect on the sugar release pattern. In addition, complete hydrolysis to glucose was observed with enzyme preparation having at least a cellobiase units (CBU)/carboxymethyl cellulose (CMC) ratio (>0.15), while a modified enzyme ratio can be used for oligosaccharide synthesis. Thus, cellulase preparation with defined ratios of the three main enzymes can improve the saccharification which is of utmost importance in defining the success of lignocellulose-based economies.

49 CFR 237.55 - Railroad bridge supervisors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Railroad bridge supervisors. 237.55 Section 237.55..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.55 Railroad bridge supervisors. A railroad bridge supervisor shall be a person, regardless of...

9 CFR 2.37 - Federal research facilities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Federal research facilities. 2.37 Section 2.37 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE ANIMAL WELFARE REGULATIONS Research Facilities § 2.37 Federal research facilities. Each Federal...

47 CFR 87.237 - Scope of service.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Scope of service. 87.237 Section 87.237 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES AVIATION SERVICES Aeronautical Multicom Stations § 87.237 Scope of service. (a) The communications of an aeronautical multicom...

49 CFR 237.155 - Documents and records.

Code of Federal Regulations, 2012 CFR

2012-10-01

..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Documentation, Records, and Audits of Bridge Management Programs § 237.155 Documents and records. Each track owner required to implement a bridge management... 49 Transportation 4 2012-10-01 2012-10-01 false Documents and records. 237.155 Section 237.155...

49 CFR 237.55 - Railroad bridge supervisors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Railroad bridge supervisors. 237.55 Section 237.55..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.55 Railroad bridge supervisors. A railroad bridge supervisor shall be a person, regardless of...

Compositions and methods comprising cellulase variants with reduced affinity to non-cellulosic materials

DOEpatents

Cascao-Pereira, Luis; Kaper, Thijs; Kelemen, Bradley R.; Liu, Amy D.

2017-07-04

The present disclosure relates to cellulase variants. In particular the present disclosure relates to cellulase variants having reduced binding to non-cellulosic materials. Also described are nucleic acids encoding the cellulase, compositions comprising said cellulase, methods of identifying cellulose variants and methods of using the compositions.

Compositions and methods comprising cellulase variants with reduced affinity to non-cellulosic materials

DOEpatents

Cascao-Pereira, Luis G; Kaper, Thijs; Kelemen, Bradley R; Liu, Amy D

2015-04-07

The present disclosure relates to cellulase variants. In particular the present disclosure relates to cellulase variants having reduced binding to non-cellulosic materials. Also described are nucleic acids encoding the cellulase, compositions comprising said cellulase, methods of identifying cellulose variants and methods of using the compositions.

Compositions and methods comprising cellulase variants with reduced affinity to non-cellulosic materials

DOEpatents

Cascao-Pereira, Luis G.; Kaper, Thijs; Kelemen, Bradley R; Liu, Amy D.

2012-08-07

The present disclosure relates to cellulase variants. In particular the present disclosure relates to cellulase variants having reduced binding to non-cellulosic materials. Also described are nucleic acids encoding the cellulase, compositions comprising said cellulase, methods of identifying cellulose variants and methods of using the compositions.

49 CFR 237.53 - Railroad bridge inspectors.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Railroad bridge inspectors. 237.53 Section 237.53..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge inspector shall be a person who is determined by...

49 CFR 237.109 - Bridge inspection records.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Bridge inspection records. 237.109 Section 237.109..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.109 Bridge inspection records... performed on those bridges under this part. (b) Each record of an inspection under the bridge management...

49 CFR 237.53 - Railroad bridge inspectors.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Railroad bridge inspectors. 237.53 Section 237.53..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Qualifications and Designations of Responsible Persons § 237.53 Railroad bridge inspectors. A railroad bridge inspector shall be a person who is determined by...

49 CFR 237.109 - Bridge inspection records.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Bridge inspection records. 237.109 Section 237.109..., DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.109 Bridge inspection records... performed on those bridges under this part. (b) Each record of an inspection under the bridge management...

34 CFR 237.7 - What regulations apply?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false What regulations apply? 237.7 Section 237.7 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION CHRISTA MCAULIFFE FELLOWSHIP PROGRAM General § 237.7 What regulations apply? The...

34 CFR 237.7 - What regulations apply?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 1 2014-07-01 2014-07-01 false What regulations apply? 237.7 Section 237.7 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION CHRISTA MCAULIFFE FELLOWSHIP PROGRAM General § 237.7 What regulations apply? The...

12 CFR 237.20 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... the Board's Regulation K (12 CFR 211.21(n)). Major security-based swap participant has the same... 12 Banks and Banking 4 2014-01-01 2014-01-01 false Definitions. 237.20 Section 237.20 Banks and Banking FEDERAL RESERVE SYSTEM (CONTINUED) BOARD OF GOVERNORS OF THE FEDERAL RESERVE SYSTEM (CONTINUED...

14 CFR 23.237 - Operation on water.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Operation on water. 23.237 Section 23.237... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 23.237 Operation on water. A wave height, demonstrated to be safe for operation, and any...

46 CFR 108.237 - Fuel storage facilities.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 46 Shipping 4 2013-10-01 2013-10-01 false Fuel storage facilities. 108.237 Section 108.237... AND EQUIPMENT Construction and Arrangement Helicopter Facilities § 108.237 Fuel storage facilities. (a) Helicopter fuel storage tanks must be installed as far as practicable from— (1) The landing area; and (2...

46 CFR 108.237 - Fuel storage facilities.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 46 Shipping 4 2012-10-01 2012-10-01 false Fuel storage facilities. 108.237 Section 108.237... AND EQUIPMENT Construction and Arrangement Helicopter Facilities § 108.237 Fuel storage facilities. (a) Helicopter fuel storage tanks must be installed as far as practicable from— (1) The landing area; and (2...

46 CFR 108.237 - Fuel storage facilities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Fuel storage facilities. 108.237 Section 108.237... AND EQUIPMENT Construction and Arrangement Helicopter Facilities § 108.237 Fuel storage facilities. (a) Helicopter fuel storage tanks must be installed as far as practicable from— (1) The landing area; and (2...

46 CFR 108.237 - Fuel storage facilities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 4 2011-10-01 2011-10-01 false Fuel storage facilities. 108.237 Section 108.237... AND EQUIPMENT Construction and Arrangement Helicopter Facilities § 108.237 Fuel storage facilities. (a) Helicopter fuel storage tanks must be installed as far as practicable from— (1) The landing area; and (2...

14 CFR 23.237 - Operation on water.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Operation on water. 23.237 Section 23.237... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 23.237 Operation on water. A wave height, demonstrated to be safe for operation, and any...

14 CFR 23.237 - Operation on water.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Operation on water. 23.237 Section 23.237... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 23.237 Operation on water. A wave height, demonstrated to be safe for operation, and any...

14 CFR 23.237 - Operation on water.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Operation on water. 23.237 Section 23.237... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Flight Ground and Water Handling Characteristics § 23.237 Operation on water. A wave height, demonstrated to be safe for operation, and any...

34 CFR 237.8 - What definitions apply?

Code of Federal Regulations, 2010 CFR

2010-07-01

... 34 Education 1 2010-07-01 2010-07-01 false What definitions apply? 237.8 Section 237.8 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION CHRISTA MCAULIFFE FELLOWSHIP PROGRAM General § 237.8 What definitions apply? (a) The...

34 CFR 237.8 - What definitions apply?

Code of Federal Regulations, 2014 CFR

2014-07-01

... 34 Education 1 2014-07-01 2014-07-01 false What definitions apply? 237.8 Section 237.8 Education Regulations of the Offices of the Department of Education OFFICE OF ELEMENTARY AND SECONDARY EDUCATION, DEPARTMENT OF EDUCATION CHRISTA MCAULIFFE FELLOWSHIP PROGRAM General § 237.8 What definitions apply? (a) The...

Thermostable cellulases, and mutants thereof, capable of hydrolyzing cellulose in ionic liquid

DOEpatents

Sapra, Rajat; Datta, Supratim; Chen, Zhiwei; Holmes, Bradley M.; Simmons, Blake A.; Blanch, Harvey W.

2016-04-26

The present invention provides for a composition comprising an ionic liquid and a thermostable cellulose, and a method of hydrolyzing a cellulose, comprising: (a) providing a composition comprising a solution comprising an ionic liquid and a cellulose, and (b) introducing a thermostable cellulase to the solution, such that the cellulose is hydrolyzed by the cellulase. The present invention also provides for a Thermatoga maritima thermostable cellulase mutant with increased cellulase activity.

Enhanced processive cellulases

DOEpatents

Adney, William S.; Beckham, Gregg T.; Jarvis, Eric; Himmel, Michael E.; Decker, Stephen R.; Linger, Jeffrey G.; Podkaminer, Kara; Baker, John O.; Taylor, II, Larry; Xu, Qi; Singh, Arjun

2017-06-20

Nucleic acid sequences encoding chimeric polypeptides that exhibit enhanced cellulase activities are disclosed herein. These nucleic acids may be expressed in hosts such as fungi, which in turn may be cultured to produce chimeric polypeptides. Also disclosed are chimeric polypeptides and their use in the degradation of cellulosic materials.

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 9 2011-10-01 2011-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 9 2013-10-01 2013-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 9 2012-10-01 2012-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 9 2014-10-01 2014-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

49 CFR 1544.237 - Flight deck privileges.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 9 2010-10-01 2010-10-01 false Flight deck privileges. 1544.237 Section 1544.237... COMMERCIAL OPERATORS Operations § 1544.237 Flight deck privileges. (a) For each aircraft that has a door to the flight deck, each aircraft operator must restrict access to the flight deck as provided in its...

48 CFR 252.237-7008 - Group interment.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Group interment. 252.237... Clauses 252.237-7008 Group interment. As prescribed in 237.7003(b), use the following clause: Group... interred as a group on the basis of the number of caskets furnished, rather than on the basis of the number...

48 CFR 252.237-7008 - Group interment.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Group interment. 252.237... Clauses 252.237-7008 Group interment. As prescribed in 237.7003(b), use the following clause: Group... interred as a group on the basis of the number of caskets furnished, rather than on the basis of the number...

48 CFR 252.237-7008 - Group interment.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Group interment. 252.237... Clauses 252.237-7008 Group interment. As prescribed in 237.7003(b), use the following clause: Group... interred as a group on the basis of the number of caskets furnished, rather than on the basis of the number...

48 CFR 252.237-7008 - Group interment.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Group interment. 252.237... Clauses 252.237-7008 Group interment. As prescribed in 237.7003(b), use the following clause: Group... interred as a group on the basis of the number of caskets furnished, rather than on the basis of the number...

48 CFR 252.237-7008 - Group interment.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Group interment. 252.237... Clauses 252.237-7008 Group interment. As prescribed in 237.7003(b), use the following clause: Group... interred as a group on the basis of the number of caskets furnished, rather than on the basis of the number...

Influence of rice straw polyphenols on cellulase production by Trichoderma reesei.

PubMed

Zheng, Wei; Zheng, Qin; Xue, Yiyun; Hu, Jiajun; Gao, Min-Tian

2017-06-01

In this study, we found that during cellulase production by Trichoderma reesei large amounts of polyphenols were released from rice straw when the latter was used as the carbon source. We identified and quantified the phenolic compounds in rice straw and investigated the effects of the phenolic compounds on cellulase production by T. reesei. The phenolic compounds of rice straw mainly consisted of phenolic acids and tannins. Coumaric acid (CA) and ferulic acid (FA) were the predominant phenolic acids, which inhibited cellulase production by T. reesei. When the concentrations of CA and FA in the broth increased to 0.06 g/L, cellulase activity decreased by 23% compared with that in the control culture. Even though the rice straw had a lower tannin than phenolic acid content, the tannins had a greater inhibitory effect than the phenolic acids on cellulase production by T. reesei. Tannin concentrations greater than 0.3 g/L completely inhibited cellulase production. Thus, phenolic compounds, especially tannins are the major inhibitors of cellulase production by T. reesei. Therefore, we studied the effects of pretreatments on the release of phenolic compounds. Ball milling played an important role in the release of FA and CA, and hot water extraction was highly efficient in removing tannins. By combining ball milling with extraction by water, the 2-fold higher cellulase activity than in the control culture was obtained. Copyright © 2017 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

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

PubMed

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.

Inhibitory effect of vanillin on cellulase activity in hydrolysis of cellulosic biomass.

PubMed

Li, Yun; Qi, Benkun; Wan, Yinhua

2014-09-01

Pretreatment of lignocellulosic material produces a wide variety of inhibitory compounds, which strongly inhibit the following enzymatic hydrolysis of cellulosic biomass. Vanillin is a kind of phenolics derived from degradation of lignin. The effect of vanillin on cellulase activity for the hydrolysis of cellulose was investigated in detail. The results clearly showed that vanillin can reversibly and non-competitively inhibit the cellulase activity at appropriate concentrations and the value of IC50 was estimated to be 30 g/L. The inhibition kinetics of cellulase by vanillin was studied using HCH-1 model and inhibition constants were determined. Moreover, investigation of three compounds with similar structure of vanillin on cellulase activity demonstrated that aldehyde group and phenolic hydroxyl groups of vanillin had inhibitory effect on cellulase. These results provide valuable and detailed information for understanding the inhibition of lignin derived phenolics on cellulase. Copyright © 2014 Elsevier Ltd. All rights reserved.

Successive construction of cellulase hyperproducers of Trichoderma using hyperpolyploids.

PubMed

Toyama, H; Toyama, N

2000-01-01

When the swollen conidia of Trichoderma reesei QM 6a are treated with 0.1% (w/v) colchicine solution, huge autopolyploid nuclei can be formed in those swollen conidia. When a mycelial mat derived from such a conidum is treated with a haploidizing reagent, benomyl, many fan-shaped sectors are produced from the colony, and cellulase hyperproducers are selected from conidia on the colony. When colchicine and benomyl treatments are repeated on cellulase hyperproducers, new hyperproducers can be constructed successively and systematically. Moreover, when conidia derived from autopolyploids are treated with ethylmethanesulfonate solution, another type of cellulase hyperproducers (polyploids) can be obtained.

33 CFR 136.237 - Authorized claimants.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 2 2012-07-01 2012-07-01 false Authorized claimants. 136.237 Section 136.237 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; CLAIMS...

33 CFR 136.237 - Authorized claimants.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 2 2011-07-01 2011-07-01 false Authorized claimants. 136.237 Section 136.237 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; CLAIMS...

33 CFR 136.237 - Authorized claimants.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 2 2013-07-01 2013-07-01 false Authorized claimants. 136.237 Section 136.237 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; CLAIMS...

33 CFR 136.237 - Authorized claimants.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 2 2014-07-01 2014-07-01 false Authorized claimants. 136.237 Section 136.237 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; CLAIMS...

33 CFR 136.237 - Authorized claimants.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 2 2010-07-01 2010-07-01 false Authorized claimants. 136.237 Section 136.237 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) MARINE POLLUTION FINANCIAL RESPONSIBILITY AND COMPENSATION OIL SPILL LIABILITY TRUST FUND; CLAIMS...

Cellulase immobilization on magnetic nanoparticles encapsulated in polymer nanospheres.

PubMed

Lima, Janaina S; Araújo, Pedro H H; Sayer, Claudia; Souza, Antonio A U; Viegas, Alexandre C; de Oliveira, Débora

2017-04-01

Immobilization of cellulases on magnetic nanoparticles, especially magnetite nanoparticles, has been the main approach studied to make this enzyme, economically and industrially, more attractive. However, magnetite nanoparticles tend to agglomerate, are very reactive and easily oxidized in air, which has strong impact on their useful life. Thus, it is very important to provide proper surface coating to avoid the mentioned problems. This study aimed to investigate the immobilization of cellulase on magnetic nanoparticles encapsulated in polymeric nanospheres. The support was characterized in terms of morphology, average diameter, magnetic behavior and thermal decomposition analyses. The polymer nanospheres containing encapsulated magnetic nanoparticles showed superparamagnetic behavior and intensity average diameter about 150 nm. Immobilized cellulase exhibited broader temperature stability than in the free form and great reusability capacity, 69% of the initial enzyme activity was maintained after eight cycles of use. The magnetic support showed potential for cellulase immobilization and allowed fast and easy biocatalyst recovery through a single magnet.

Genetically enhanced cellulase production in Pseudomonas cellulosa using recombinant DNA technology

DOEpatents

Dees, H. Craig

1999-01-01

An enhanced strain of Pseudomonas celllulosa was obtained by introducing a recombinant genetic construct comprising a heterologous cellulase gene operably connected to a promoter into ATCC 55702, mutagenizing the transformants by treatment with MNNG, and selecting a high cellulase producing transformant. The transformant, designated Pseudomonas cellulosa ATCC XXXX, exhibits enhanced levels of cellulase production relative to the untransformed Pseudomonas cellulosa strain #142 ATCC 55702.

Discovery of new cellulases from the metagenome by a metagenomics-guided strategy.

PubMed

Yang, Chao; Xia, Yu; Qu, Hong; Li, An-Dong; Liu, Ruihua; Wang, Yubo; Zhang, Tong

2016-01-01

Energy shortage has become a global problem. Production of biofuels from renewable biomass resources is an inevitable trend of sustainable development. Cellulose is the most abundant and renewable resource in nature. Lack of new cellulases with unique properties has become the bottleneck of the efficient utilization of cellulose. Environmental metagenomes are regarded as huge reservoirs for a variety of cellulases. However, new cellulases cannot be obtained easily by functional screening of metagenomic libraries. In this work, a metagenomics-guided strategy for obtaining new cellulases from the metagenome was proposed. Metagenomic sequences of DNA extracted from the anaerobic beer lees converting consortium enriched at thermophilic conditions were assembled, and 23 glycoside hydrolase (GH) sequences affiliated with the GH family 5 were identified. Among the 23 GH sequences, three target sequences (designated as cel7482, cel3623 and cel36) showing low identity with those known GHs were chosen as the putative cellulase genes to be functionally expressed in Escherichia coli after PCR cloning. The three cellulases were classified into endo-β-1,4-glucanases by product pattern analysis. The recombinant cellulases were more active at pH 5.5 and within a temperature range of 60-70 °C. Computer-assisted 3D structure modeling indicated that the active residues in the active site of the recombinant cellulases were more similar to each other compared with non-active site residues. The recombinant cel7482 was extremely tolerant to 2 M NaCl, suggesting that cel7482 may be a halotolerant cellulase. Moreover, the recombinant cel7482 was shown to have an ability to resist three ionic liquids (ILs), which are widely used for cellulose pretreatment. Furthermore, active cel7482 was secreted by the twin-arginine translocation (Tat) pathway of Bacillus subtilis 168 into the culture medium, which facilitates the subsequent purification and reduces the formation of inclusion body in

49 CFR 237.107 - Conduct of bridge inspections.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Conduct of bridge inspections. 237.107 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge inspections. Bridge inspections shall be conducted under the direct supervision of a designated...

49 CFR 237.107 - Conduct of bridge inspections.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Conduct of bridge inspections. 237.107 Section 237... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.107 Conduct of bridge inspections. Bridge inspections shall be conducted under the direct supervision of a designated...

36 CFR 2.37 - Noncommercial soliciting.

Code of Federal Regulations, 2010 CFR

2010-07-01

....37 Section 2.37 Parks, Forests, and Public Property NATIONAL PARK SERVICE, DEPARTMENT OF THE INTERIOR RESOURCE PROTECTION, PUBLIC USE AND RECREATION § 2.37 Noncommercial soliciting. Soliciting or demanding gifts, money, goods or services is prohibited, except pursuant to the terms and conditions of a permit...

Measurement of filter paper activities of cellulase with microplate-based assay.

PubMed

Yu, Xiaoxiao; Liu, Yan; Cui, Yuxiao; Cheng, Qiyue; Zhang, Zaixiao; Lu, Jia Hui; Meng, Qingfan; Teng, Lirong; Ren, Xiaodong

2016-01-01

It is always a challenge to determine the total cellulase activity efficiently without reducing accuracy. The most common total cellulase activity assay is the filter paper assay (FPA) established by the International Union of Pure and Applied Chemistry (IUPAC). A new procedure to measure the FPA with microplate-based assay was studied in this work, which followed the main idea of IUPAC to dilute cellulase preparation to get fixed glucose release. FPAs of six cellulase preparations were determined with the microplate-based assay. It is shown that FPAs of cellulase Youtell, RCconc, R-10, Lerkam, Yishui and Sinopharm were 67.9, 46.0, 46.1, 27.4, 7.6 and 8.0 IU/ml respectively. There was no significant difference at the 95% confidence level between the FPA determined with IUPAC and the microplate-based assay. It could be concluded that the FPA could be determined by the microplate-based assay with the same accuracy and much more efficiency compared with that by IUPAC.

Measurement of filter paper activities of cellulase with microplate-based assay

PubMed Central

Yu, Xiaoxiao; Liu, Yan; Cui, Yuxiao; Cheng, Qiyue; Zhang, Zaixiao; Lu, Jia Hui; Meng, Qingfan; Teng, Lirong; Ren, Xiaodong

2015-01-01

It is always a challenge to determine the total cellulase activity efficiently without reducing accuracy. The most common total cellulase activity assay is the filter paper assay (FPA) established by the International Union of Pure and Applied Chemistry (IUPAC). A new procedure to measure the FPA with microplate-based assay was studied in this work, which followed the main idea of IUPAC to dilute cellulase preparation to get fixed glucose release. FPAs of six cellulase preparations were determined with the microplate-based assay. It is shown that FPAs of cellulase Youtell, RCconc, R-10, Lerkam, Yishui and Sinopharm were 67.9, 46.0, 46.1, 27.4, 7.6 and 8.0 IU/ml respectively. There was no significant difference at the 95% confidence level between the FPA determined with IUPAC and the microplate-based assay. It could be concluded that the FPA could be determined by the microplate-based assay with the same accuracy and much more efficiency compared with that by IUPAC. PMID:26858572

High consistency cellulase treatment of hardwood prehydrolysis kraft based dissolving pulp.

PubMed

Wang, Qiang; Liu, Shanshan; Yang, Guihua; Chen, Jiachuan; Ni, Yonghao

2015-01-01

For enzymatic treatment of dissolving pulp, there is a need to improve the process to facilitate its commercialization. For this purpose, the high consistency cellulase treatment was conducted based on the hypothesis that a high cellulose concentration would favor the interactions of cellulase and cellulose, thus improves the cellulase efficiency while decreasing the water usage. The results showed that compared with a low consistency of 3%, the high consistency of 20% led to 24% increases of cellulase adsorption ratio. As a result, the viscosity decrease and Fock reactivity increase at consistency of 20% were enhanced from 510 mL/g and 70.3% to 471 mL/g and 77.6%, respectively, compared with low consistency of 3% at 24h. The results on other properties such as alpha cellulose, alkali solubility and molecular weight distribution also supported the conclusion that a high consistency of cellulase treatment was more effective than a low pulp consistency process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enzymes in Commercial Cellulase Preparations Bind Differently to Dioxane Extracted Lignins

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yarbrough, John M.; Mittal, Ashutosh; Katahira, Rui

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 hydrolasemore » 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

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

PubMed

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.

Engineering Cellulase Enzymes for Bioenergy

NASA Astrophysics Data System (ADS)

Atreya, Meera Elizabeth

Sustainable energy sources, such as biofuels, offer increasingly important alternatives to fossil fuels that contribute less to global climate change. The energy contained within cellulosic biofuels derives from sunlight energy stored in the form of carbon-carbon bonds comprising sugars such as glucose. Second-generation biofuels are produced from lignocellulosic biomass feedstocks, including agricultural waste products and non-food crops like Miscanthus, that contain lignin and the polysaccharides hemicellulose and cellulose. Cellulose is the most abundant biological material on Earth; it is a polymer of glucose and a structural component of plant cell walls. Accessing the sugar is challenging, as the crystalline structure of cellulose resists degradation; biochemical and thermochemical means can be used to depolymerize cellulose. Cellulase enzymes catalyze the biochemical depolymerization of cellulose into glucose. Glucose can be used as a carbon source for growth of a biofuel-producing microorganism. When it converts glucose to a hydrocarbon fuel, this microbe completes the biofuels process of transforming sunlight energy into accessible, chemical energy capable of replacing non-renewable transportation fuels. Due to strong intermolecular interactions between polymer chains, cellulose is significantly more challenging to depolymerize than starch, a more accessible polymer of glucose utilized in first-generation biofuels processes (often derived from corn). While most mammals cannot digest cellulose (dietary fiber), certain fungi and bacteria produce cellulase enzymes capable of hydrolyzing it. These organisms secrete a wide variety of glycoside hydrolase and other classes of enzymes that work in concert. Because cellulase enzymes are slow-acting and expensive to produce, my aim has been to improve the properties of these enzymes as a means to make a cellulosic biofuels process possible that is more efficient and, consequently, more economical than current

Fluorescent cellulose microfibrils as substrate for the detection of cellulase activity.

PubMed

Helbert, William; Chanzy, Henri; Husum, Tommy Lykke; Schülein, Martin; Ernst, Steffen

2003-01-01

To devise a sensitive cellulase assay based on substrates having most of the physical characteristics of native cellulose, 5-(4,6-dichlorotriazinyl)aminofluorescein (DTAF) was used as a grafting agent to prepare suspensions of fluorescent microfibrils from bacterial cellulose. These suspensions were digested by a series of commercially relevant cellulases from Humicola insolens origin: cloned Cel6B and Cel 45A as well as crude H. insolens complex. The digestion induced the release of fluorescent cellodextrins as well as reducing sugars. After adequate centrifugation, these soluble products were analyzed as a function of grafting content, digestion time, and cellulase characteristics. The resulting data allowed the grafting conditions to be optimized in order to maximize the quantity of soluble products and therefore to increase the sensitivity of the detection. A comparison between the amount of released fluorescence and that of released reducing sugar allowed the differentiation between processive exo and endo cellulase activities. The casting of films of DTAF-grafted microfibrils at the bottom of the microwell titer plates also led to sensitive cellulase detection. As these films kept their integrity and remained firmly glued to the well bottom during the digestion time, they are tailored made for a full automation of the cellulases testing.

Bioconversion potential of Trichoderma viride HN1 cellulase for a lignocellulosic biomass Saccharum spontaneum.

PubMed

Iqtedar, Mehwish; Nadeem, Mohammad; Naeem, Hira; Abdullah, Roheena; Naz, Shagufta; Qurat ul Ain Syed; Kaleem, Afshan

2015-01-01

The industrialisation of lignocellulose conversion is impeded by expensive cellulase enzymes required for saccharification in bioethanol production. Current research undertakes cellulase production from pretreated Saccharum spontaneum through Trichoderma viride HN1 under submerged fermentation conditions. Pretreatment of substrate with 2% NaOH resulted in 88% delignification. Maximum cellulase production (2603 ± 16.39 U/mL/min carboxymethyl cellulase and 1393 ± 25.55 U/mL/min FPase) was achieved at 6% substrate at pH 5.0, with 5% inoculum, incubated at 35°C for 120 h of fermentation period. Addition of surfactant, Tween 80 and metal ion Mn(+2), significantly enhanced cellulase yield. This study accounts proficient cellulase yield through process optimisation by exploiting cheaper substrate to escalate their commercial endeavour.

32 CFR 237a.1 - Purpose.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 32 National Defense 2 2010-07-01 2010-07-01 false Purpose. 237a.1 Section 237a.1 National Defense Department of Defense (Continued) OFFICE OF THE SECRETARY OF DEFENSE (CONTINUED) MISCELLANEOUS PUBLIC AFFAIRS... with industry on (1) public affairs matters in general, (2) industry-sponsored events, and (3...

17 CFR 256.237 - Interest accrued.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 17 Commodity and Securities Exchanges 3 2011-04-01 2011-04-01 false Interest accrued. 256.237... COMPANY ACT OF 1935 7. Current and Accrued Liabilities § 256.237 Interest accrued. This account shall include the amount of interest accrued on all liabilities of the service company. Supporting records shall...

17 CFR 256.237 - Interest accrued.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 17 Commodity and Securities Exchanges 3 2010-04-01 2010-04-01 false Interest accrued. 256.237... COMPANY ACT OF 1935 7. Current and Accrued Liabilities § 256.237 Interest accrued. This account shall include the amount of interest accrued on all liabilities of the service company. Supporting records shall...

Poly(acrylic acid) nanogel as a substrate for cellulase immobilization for hydrolysis of cellulose.

PubMed

Ahmed, Ibrahim Nasser; Chang, Ray; Tsai, Wei-Bor

2017-04-01

Cellulase was adsorbed onto poly(acrylic acid), PAA, nanogel, that was fabricated via inverse-phase microemulsion polymerization. The PAA nanogel was around 150nm in diameter and enriched with carboxyl groups. The surface charge of PAA nanogel depended on the pHs of the environment and affected the adsorption of cellulase. The temperature stability of the immobilized cellulase was greatly enhanced in comparison to the free enzyme, especially at high temperature. At 80°C, the immobilized cellulase remained ∼75% of hydrolytic activity, in comparison to ∼55% for the free cellulase. Furthermore, the immobilized cellulase was more active than the free enzyme in acidic buffers. The immobilized cellulase could be recovered via centrifugation and can be used repeatedly, although the recovery ratio needs further improvement. In conclusion, PAA nanogel has the potential in the application of enzyme immobilization for biochemical processes. Copyright © 2017 Elsevier B.V. All rights reserved.

32 CFR 237a.3 - Objective and policy.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 32 National Defense 2 2011-07-01 2011-07-01 false Objective and policy. 237a.3 Section 237a.3...) MISCELLANEOUS PUBLIC AFFAIRS LIAISON WITH INDUSTRY § 237a.3 Objective and policy. (a) It is important that... subchapter, DoD components shall cooperate with industry at local and regional levels. However, they will...

Cellulase production by pink pigmented facultative methylotrophic strains (PPFMs).

PubMed

Jayashree, Shanmugam; Lalitha, Rajendran; Vadivukkarasi, Ponnusamy; Kato, Yuko; Seshadri, Sundaram

2011-07-01

Pink pigmented facultative methylotrophs (PPFM) isolated from water samples of Cooum and Adyar rivers in Chennai and soil samples of forests located in various districts of Tamil Nadu, India were screened for cellulase production using carboxymethylcellulose agar (CMC agar) medium. The strains showed wide variations in the production of clearing zones around the colonies on CMC agar medium flooded with Congo red. CMCase and filter paper assays were used to quantitatively measure the cellulase activity of 13 PPFM strains. Among the strains, Methylobacterium gregans, MNW 60, MHW 109, MSF 34, and MSF 40 showed cellulolytic activity ranging from 0.73 to 1.16 U mL(-1) with wide temperature (35-65°C) and pH (5 to 8) tolerance. SDS-PAGE analysis of the crude enzyme of PPFM strain MNW 60 exhibited several protein bands, and zymogram analysis revealed two dimeric cellulase bands with molecular mass of ~92 and 42 kDa. Scanning electron microscopic studies revealed significant morphological differences between the cells grown in normal and CMC amended medium. The strain MNW 60 was identified as Methylobacterium sp. based on biochemical, physiological, and morphological analyses, and the methylotrophic nature was authenticated by the presence of mxaF gene, encoding methanol dehydrogenase as a key indicator enzyme of methylotrophs, with 99% similarity to Methylobacterium lusitanum. With the 16S ribosomal RNA sequence showing 97% similarity to M. lusitanum strain MP2, this can be proposed as a novel taxon of the genus Methylobacterium. The study forms the first detailed report on the extracellular cellulase production by pink pigmented Methylobacterium sp., and it is expected that this might be the basis for further studies on cellulase production by PPFMs to explore the molecular mechanism, strain improvement, and large-scale cellulase production for its application.

Enhanced cellulase producing mutants developed from heterokaryotic Aspergillus strain.

PubMed

Kaur, Baljit; Oberoi, H S; Chadha, B S

2014-03-01

A heterokaryon 28, derived through protoplast fusion between Aspergillus nidulans and Aspergillus tubingensis (Dal8), was subjected cyclic mutagenesis followed by selection on increasing levels of 2-deoxy glucose (2-DG) as selection marker. The derived deregulated cellulase hyper producing mutant '64', when compared to fusant 28, produced 9.83, 7.8, 3.2, 4.2 and 19.74 folds higher endoglucanase, β-glucosidase, cellobiohydrolase, FPase and xylanase, respectively, under shake cultures. The sequence analysis of PCR amplified β-glucosidase gene from wild and mutant showed nucleotide deletion/substitution. The mutants showed highly catalytic efficient β-glucosidase as evident from low Km and high Vmax values. The expression profiling through zymogram analysis also indicated towards over-expression of cellulases. The up/down regulated expressed proteins observed through SDS-PAGE were identified by Peptide mass fingerprinting The cellulase produced by mutants in conjunction with cellulase free xylanase derived from Thermomyces lanuginosus was used for efficient utilization of alkali treated rice straw for obtaining xylo-oligosaccharides and ethanol. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effects of rhamnolipid on the cellulase and xylanase in hydrolysis of wheat straw.

PubMed

Wang, Hong-Yuan; Fan, Bing-Quan; Li, Chun-Hua; Liu, Shuang; Li, Min

2011-06-01

The effects of biosurfactant rhamnolipid (RL) and chemical surfactant Triton X-100 on the production of cellulases and xylanase from Penicillium expansum (P. expansum) in untreated, acid- and alkali-pretreated wheat straw submerged fermentations were studied, and the influences on the activity and stability of Cellulase R-10 were also investigated. The results showed that RL and Triton X-100 enhanced the activities of cellulases and xylanase to different extents and the stimulatory effects of RL were superior to those of Triton X-100. During the peak enzyme production phase, RL (60 RE mg/l) increased cellulases activities by 25.5-102.9%, in which the raise of the same enzyme in acid-pretreated straw broths was the most. It was found that the reducing sugars by hydrolyzing wheat straw with Cellulase R-100 were not visibly increased after adding RL. However, it distinctly protected Cellulase R-10 from degradation or inactivation, keeping the reducing sugars yield at about 17%. Copyright © 2011. Published by Elsevier Ltd.

Cellulase production by Penicillium funiculosum and its application in the hydrolysis of sugar cane bagasse for second generation ethanol production by fed batch operation.

PubMed

Maeda, Roberto Nobuyuki; Barcelos, Carolina Araújo; Santa Anna, Lídia Maria Melo; Pereira, Nei

2013-01-10

This study aimed to produce a cellulase blend and to evaluate its application in a simultaneous saccharification and fermentation (SSF) process for second generation ethanol production from sugar cane bagasse. The sugar cane bagasse was subjected to pretreatments (diluted acid and alkaline), as for disorganizing the ligocellulosic complex, and making the cellulose component more amenable to enzymatic hydrolysis. The residual solid fraction was named sugar cane bagasse partially delignified cellulignin (PDC), and was used for enzyme production and ethanol fermentation. The enzyme production was performed in a bioreactor with two inoculum concentrations (5 and 10% v/v). The fermentation inoculated with higher inoculum size reduced the time for maximum enzyme production (from 72 to 48). The enzyme extract was concentrated using tangential ultrafiltration in hollow fiber membranes, and the produced cellulase blend was evaluated for its stability at 37 °C, operation temperature of the simultaneous SSF process, and at 50 °C, optimum temperature of cellulase blend activity. The cellulolytic preparation was stable for at least 300 h at both 37 °C and 50 °C. The ethanol production was carried out by PDC fed-batch SSF process, using the onsite cellulase blend. The feeding strategy circumvented the classic problems of diffusion limitations by diminishing the presence of a high solid:liquid ratio at any time, resulting in high ethanol concentration at the end of the process (100 g/L), which corresponded to a fermentation efficiency of 78% of the maximum obtainable theoretically. The experimental results led to the ratio of 380 L of ethanol per ton of sugar cane bagasse PDC. Copyright © 2012 Elsevier B.V. All rights reserved.

Visualizing cellulase activity.

PubMed

Bubner, Patricia; Plank, Harald; Nidetzky, Bernd

2013-06-01

Commercial exploitation of lignocellulose for biotechnological production of fuels and commodity chemicals requires efficient-usually enzymatic-saccharification of the highly recalcitrant insoluble substrate. A key characteristic of cellulose conversion is that the actual hydrolysis of the polysaccharide chains is intrinsically entangled with physical disruption of substrate morphology and structure. This "substrate deconstruction" by cellulase activity is a slow, yet markedly dynamic process that occurs at different length scales from and above the nanometer range. Little is currently known about the role of progressive substrate deconstruction on hydrolysis efficiency. Application of advanced visualization techniques to the characterization of enzymatic degradation of different celluloses has provided important new insights, at the requisite nano-scale resolution and down to the level of single enzyme molecules, into cellulase activity on the cellulose surface. Using true in situ imaging, dynamic features of enzyme action and substrate deconstruction were portrayed at different morphological levels of the cellulose, thus providing new suggestions and interpretations of rate-determining factors. Here, we review the milestones achieved through visualization, the methods which significantly promoted the field, compare suitable (model) substrates, and identify limiting factors, challenges and future tasks. Copyright © 2013 Wiley Periodicals, Inc.

The identification of and relief from Fe3+ inhibition for both cellulose and cellulase in cellulose saccharification catalyzed by cellulases from Penicillium decumbens.

PubMed

Wang, Mingyu; Mu, Ziming; Wang, Junli; Hou, Shaoli; Han, Lijuan; Dong, Yanmei; Xiao, Lin; Xia, Ruirui; Fang, Xu

2013-04-01

Lignocellulosic biomass is an underutilized, renewable resource that can be converted to biofuels. The key step in this conversion is cellulose saccharification catalyzed by cellulase. In this work, the effect of metal ions on cellulose hydrolysis by cellulases from Penicillium decumbens was reported for the first time. Fe(3+) and Cu(2+) were shown to be inhibitory. Further studies on Fe(3+) inhibition showed the inhibition takes place on both enzyme and substrate levels. Fe(3+) treatment damages cellulases' capability to degrade cellulose and inhibits all major cellulase activities. Fe(3+) treatment also reduces the digestibility of cellulose, due to its oxidation. Treatment of Fe(3+)-treated cellulose with DTT and supplementation of EDTA to saccharification systems partially relieved Fe(3+) inhibition. It was concluded that Fe(3+) inhibition in cellulose degradation is a complicated process in which multiple inhibition events occur, and that relief from Fe(3+) inhibition can be achieved by the supplementation of reducing or chelating agents. Copyright © 2013 Elsevier Ltd. All rights reserved.

Preparation of cellulase concoction using differential adsorption phenomenon.

PubMed

Birhade, Sachinkumar; Pednekar, Mukesh; Sagwal, Shilpa; Odaneth, Annamma; Lali, Arvind

2017-05-28

Controlled depolymerization of cellulose is essential for the production of valuable cellooligosaccharides and cellobiose from lignocellulosic biomass. However, enzymatic cellulose hydrolysis involves multiple synergistically acting enzymes, making difficult to control the depolymerization process and generate desired product. This work exploits the varying adsorption properties of the cellulase components to the cellulosic substrate and aims to control the enzyme activity. Cellulase adsorption was favored on pretreated cellulosic biomass as compared to synthetic cellulose. Preferential adsorption of exocellulases was observed over endocellulase, while β-glucosidases remained unadsorbed. Adsorbed enzyme fraction with bound exocellulases when used for hydrolysis generated cellobiose predominantly, while the unadsorbed enzymes in the liquid fraction produced cellooligosaccharides majorly, owing to its high endocellulases activity. Thus, the differential adsorption phenomenon of the cellulase components can be used for the controlling cellulose hydrolysis for the production of an array of sugars.

Screening and characterization of amylase and cellulase activities in psychrotolerant yeasts.

PubMed

Carrasco, Mario; Villarreal, Pablo; Barahona, Salvador; Alcaíno, Jennifer; Cifuentes, Víctor; Baeza, Marcelo

2016-02-19

Amylases and cellulases have great potential for application in industries such as food, detergent, laundry, textile, baking and biofuels. A common requirement in these fields is to reduce the temperatures of the processes, leading to a continuous search for microorganisms that secrete cold-active amylases and cellulases. Psychrotolerant yeasts are good candidates because they inhabit cold-environments. In this work, we analyzed the ability of yeasts isolated from the Antarctic region to grow on starch or carboxymethylcellulose, and their potential extracellular amylases and cellulases. All tested yeasts were able to grow with soluble starch or carboxymethylcellulose as the sole carbon source; however, not all of them produced ethanol by fermentation of these carbon sources. For the majority of the yeast species, the extracellular amylase or cellulase activity was higher when cultured in medium supplemented with glucose rather than with soluble starch or carboxymethylcellulose. Additionally, higher amylase activities were observed when tested at pH 5.4 and 6.2, and at 30-37 °C, except for Rhodotorula glacialis that showed elevated activity at 10-22 °C. In general, cellulase activity was high until pH 6.2 and between 22-37 °C, while the sample from Mrakia blollopis showed high activity at 4-22 °C. Peptide mass fingerprinting analysis of a potential amylase from Tetracladium sp. of about 70 kDa, showed several peptides with positive matches with glucoamylases from other fungi. Almost all yeast species showed extracellular amylase or cellulase activity, and an inducing effect by the respective substrate was observed in a minor number of yeasts. These enzymatic activities were higher at 30 °C in most yeast, with highest amylase and cellulase activity in Tetracladium sp. and M. gelida, respectively. However, Rh. glacialis and M. blollopis displayed high amylase or cellulase activity, respectively, under 22 °C. In this sense, these yeasts are interesting

Accessory enzymes influence cellulase hydrolysis of the model substrate and the realistic lignocellulosic biomass.

PubMed

Sun, Fubao Fuebiol; Hong, Jiapeng; Hu, Jinguang; Saddler, Jack N; Fang, Xu; Zhang, Zhenyu; Shen, Song

2015-11-01

The potential of cellulase enzymes in the developing and ongoing "biorefinery" industry has provided a great motivation to develop an efficient cellulase mixture. Recent work has shown how important the role that the so-called accessory enzymes can play in an effective enzymatic hydrolysis. In this study, three newest Novozymes Cellic CTec cellulase preparations (CTec 1/2/3) were compared to hydrolyze steam pretreated lignocellulosic substrates and model substances at an identical FPA loading. These cellulase preparations were found to display significantly different hydrolytic performances irrelevant with the FPA. And this difference was even observed on the filter paper itself when the FPA based assay was revisited. The analysis of specific enzyme activity in cellulase preparations demonstrated that different accessory enzymes were mainly responsible for the discrepancy of enzymatic hydrolysis between diversified substrates and various cellulases. Such the active role of accessory enzymes present in cellulase preparations was finally verified by supplementation with β-glucosidase, xylanase and lytic polysaccharide monooxygenases AA9. This paper provides new insights into the role of accessory enzymes, which can further provide a useful reference for the rational customization of cellulase cocktails in order to realize an efficient conversion of natural lignocellulosic substrates. Copyright © 2015 Elsevier Inc. All rights reserved.

48 CFR 237.109 - Services of quasi-military armed forces.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Services of quasi-military armed forces. 237.109 Section 237.109 Federal Acquisition Regulations System DEFENSE ACQUISITION... Contracts-General 237.109 Services of quasi-military armed forces. See 237.102-70b for prohibition on...

48 CFR 237.7003 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... and contract clauses. 237.7003 Section 237.7003 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING..., Permits. (8) 252.237-7011, Preparation History. (c) Use the clause at FAR 52.245-1, Government Property...

48 CFR 237.7003 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2011 CFR

2011-10-01

... and contract clauses. 237.7003 Section 237.7003 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING..., Permits. (8) 252.237-7011, Preparation History. (c) Use the clause at FAR 52.245-1, Government Property...

48 CFR 237.7003 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2014 CFR

2014-10-01

... and contract clauses. 237.7003 Section 237.7003 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING..., Permits. (8) 252.237-7011, Preparation History. (c) Use the clause at FAR 52.245-1, Government Property...

48 CFR 237.7003 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2012 CFR

2012-10-01

... and contract clauses. 237.7003 Section 237.7003 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING..., Permits. (8) 252.237-7011, Preparation History. (c) Use the clause at FAR 52.245-1, Government Property...

48 CFR 237.7003 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2013 CFR

2013-10-01

... and contract clauses. 237.7003 Section 237.7003 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING..., Permits. (8) 252.237-7011, Preparation History. (c) Use the clause at FAR 52.245-1, Government Property...

Nutrient control for stationary phase cellulase production in Trichoderma reesei Rut C-30.

PubMed

Callow, Nicholas V; Ray, Christopher S; Kelbly, Matthew A; Ju, Lu-Kwang

2016-01-01

This work describes the use of nutrient limitations with Trichoderma reesei Rut C-30 to obtain a prolonged stationary phase cellulase production. This period of non-growth may allow for dependable cellulase production, extended fermentation periods, and the possibility to use pellet morphology for easy product separation. Phosphorus limitation was successful in halting growth and had a corresponding specific cellulase production of 5±2 FPU/g-h. Combined with the addition of Triton X-100 for fungal pellet formation and low shear conditions, a stationary phase cellulase production period in excess of 300 h was achieved, with a constant enzyme production rate of 7±1 FPU/g-h. While nitrogen limitation was also effective as a growth limiter, it, however, also prevented cellulase production. Copyright © 2015 Elsevier Inc. All rights reserved.

Bioethanol production from wheat straw via enzymatic route employing Penicillium janthinellum cellulases.

PubMed

Singhania, Reeta Rani; Saini, Jitendra Kumar; Saini, Reetu; Adsul, Mukund; Mathur, Anshu; Gupta, Ravi; Tuli, Deepak Kumar

2014-10-01

This study concerns in-house development of cellulases from a mutant Penicillium janthinellum EMS-UV-8 and its application in separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes for bioethanol production from pre-treated wheat straw. In a 5L fermentor, the above strain could produce cellulases having activity of 3.1 FPU/mL and a specific activity of 0.83 FPU/mg of protein. In-house developed cellulase worked more efficiently in case of SSF as ethanol concentration of 21.6g/L and yield of 54.4% were obtained which were higher in comparison to SHF (ethanol concentration 12 g/L and 30.2% yield). This enzyme preparation when compared with commercial cellulase for hydrolysis of pre-treated wheat straw was found competitive. This study demonstrates that P. janthinellum EMS-UV-8 is a potential fungus for future large-scale production of cellulases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Commercial cellulases and hemicellulase performance towards oil palm empty fruit bunch (OPEFB) hydrolysis

NASA Astrophysics Data System (ADS)

Abdul Fattah, S. S.; Mohamed, R.; Jahim, J. M.; Illias, R. M.; Abu Bakar, F. D.; Murad, A. M. A.

2016-11-01

In this work, commercial cellulases and hemicellulases were evaluated for their hydrolytic activity towards pretreated oil palm empty fruit bunches (OPEFB). A total of three commercial cellulase preparations, Novozyme Celluclast®, Novozyme Cellic®Ctec, Dupont Accellerase®1500, and a commercial hemicellulase preparation, Novozyme Cellic®Htec, were evaluated. The assays were performed either using the cellulase alone or cellulase in combination with the hemicellulase, formulated at different enzyme activity ratios. Among the three cellulases, the Novozyme Cellic®Ctec yielded the highest reducing sugars, whereby 32.9% hydrolysis yield of OPEFB was achieved. The addition of the commercial hemicellulase to Celluclast® and Accellerase®1500 enhanced OPEFB hydrolysis. However, the addition of the hemicellulase to Cellic®Ctec, failed to enhance the production of the reducing sugars. Nevertheless, the amount of reducing sugars produced using Cellic®Ctec alone was the highest when compared to other enzyme combinations. It can be concluded that among the three commercial cellulases evaluated, the Novozyme Cellic®Ctec is the best enzyme for OPEFB hydrolysis.

The productive cellulase binding capacity of cellulosic substrates.

PubMed

Karuna, Nardrapee; Jeoh, Tina

2017-03-01

Cellulosic biomass is the most promising feedstock for renewable biofuel production; however, the mechanisms of the heterogeneous cellulose saccharification reaction are still unsolved. As cellulases need to bind isolated molecules of cellulose at the surface of insoluble cellulose fibrils or larger aggregated cellulose structures in order to hydrolyze glycosidic bonds, the "accessibility of cellulose to cellulases" is considered to be a reaction limiting property of cellulose. We have defined the accessibility of cellulose to cellulases as the productive binding capacity of cellulose, that is, the concentration of productive binding sites on cellulose that are accessible for binding and hydrolysis by cellulases. Productive cellulase binding to cellulose results in hydrolysis and can be quantified by measuring hydrolysis rates. In this study, we measured the productive Trichoderma reesei Cel7A (TrCel7A) binding capacity of five cellulosic substrates from different sources and processing histories. Swollen filter paper and bacterial cellulose had higher productive binding capacities of ∼6 µmol/g while filter paper, microcrystalline cellulose, and algal cellulose had lower productive binding capacities of ∼3 µmol/g. Swelling and regenerating filter paper using phosphoric acid increased the initial accessibility of the reducing ends to TrCel7A from 4 to 6 µmol/g. Moreover, this increase in initial productive binding capacity accounted in large part for the difference in the overall digestibility between filter paper and swollen filter paper. We further demonstrated that an understanding of how the productive binding capacity declines over the course of the hydrolysis reaction has the potential to predict overall saccharification time courses. Biotechnol. Bioeng. 2017;114: 533-542. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Xylose induces cellulase production in Thermoascus aurantiacus.

PubMed

Schuerg, Timo; Prahl, Jan-Philip; Gabriel, Raphael; Harth, Simon; Tachea, Firehiwot; Chen, Chyi-Shin; Miller, Matthew; Masson, Fabrice; He, Qian; Brown, Sarah; Mirshiaghi, Mona; Liang, Ling; Tom, Lauren M; Tanjore, Deepti; Sun, Ning; Pray, Todd R; Singer, Steven W

2017-01-01

Lignocellulosic biomass is an important resource for renewable production of biofuels and bioproducts. Enzymes that deconstruct this biomass are critical for the viability of biomass-based biofuel production processes. Current commercial enzyme mixtures have limited thermotolerance. Thermophilic fungi may provide enzyme mixtures with greater thermal stability leading to more robust processes. Understanding the induction of biomass-deconstructing enzymes in thermophilic fungi will provide the foundation for strategies to construct hyper-production strains. Induction of cellulases using xylan was demonstrated during cultivation of the thermophilic fungus Thermoascus aurantiacus . Simulated fed-batch conditions with xylose induced comparable levels of cellulases. These fed-batch conditions were adapted to produce enzymes in 2 and 19 L bioreactors using xylose and xylose-rich hydrolysate from dilute acid pretreatment of corn stover. Enzymes from T. aurantiacus that were produced in the xylose-fed bioreactor demonstrated comparable performance in the saccharification of deacetylated, dilute acid-pretreated corn stover when compared to a commercial enzyme mixture at 50 °C. The T. aurantiacus enzymes retained this activity at of 60 °C while the commercial enzyme mixture was largely inactivated. Xylose induces both cellulase and xylanase production in T. aurantiacus and was used to produce enzymes at up to the 19 L bioreactor scale. The demonstration of induction by xylose-rich hydrolysate and saccharification of deacetylated, dilute acid-pretreated corn stover suggests a scenario to couple biomass pretreatment with onsite enzyme production in a biorefinery. This work further demonstrates the potential for T. aurantiacus as a thermophilic platform for cellulase development.

Xylose induces cellulase production in Thermoascus aurantiacus

DOE PAGES

Schuerg, Timo; Prahl, Jan -Philip; Gabriel, Raphael; ...

2017-11-15

Lignocellulosic biomass is an important resource for renewable production of biofuels and bioproducts. Enzymes that deconstruct this biomass are critical for the viability of biomass-based biofuel production processes. Current commercial enzyme mixtures have limited thermotolerance. Thermophilic fungi may provide enzyme mixtures with greater thermal stability leading to more robust processes. Understanding the induction of biomass-deconstructing enzymes in thermophilic fungi will provide the foundation for strategies to construct hyper-production strains. Induction of cellulases using xylan was demonstrated during cultivation of the thermophilic fungus Thermoascus aurantiacus. Simulated fed-batch conditions with xylose induced comparable levels of cellulases. These fed-batch conditions were adapted tomore » produce enzymes in 2 and 19 L bioreactors using xylose and xylose-rich hydrolysate from dilute acid pretreatment of corn stover. Enzymes from T. aurantiacus that were produced in the xylose-fed bioreactor demonstrated comparable performance in the saccharification of deacetylated, dilute acid-pretreated corn stover when compared to a commercial enzyme mixture at 50 °C. The T. aurantiacus enzymes retained this activity at of 60 °C while the commercial enzyme mixture was largely inactivated. CXylose induces both cellulase and xylanase production in T. aurantiacus and was used to produce enzymes at up to the 19 L bioreactor scale. The demonstration of induction by xylose-rich hydrolysate and saccharification of deacetylated, dilute acid-pretreated corn stover suggests a scenario to couple biomass pretreatment with onsite enzyme production in a biorefinery. This work further demonstrates the potential for T. aurantiacus as a thermophilic platform for cellulase development.« less

Xylose induces cellulase production in Thermoascus aurantiacus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schuerg, Timo; Prahl, Jan -Philip; Gabriel, Raphael

Lignocellulosic biomass is an important resource for renewable production of biofuels and bioproducts. Enzymes that deconstruct this biomass are critical for the viability of biomass-based biofuel production processes. Current commercial enzyme mixtures have limited thermotolerance. Thermophilic fungi may provide enzyme mixtures with greater thermal stability leading to more robust processes. Understanding the induction of biomass-deconstructing enzymes in thermophilic fungi will provide the foundation for strategies to construct hyper-production strains. Induction of cellulases using xylan was demonstrated during cultivation of the thermophilic fungus Thermoascus aurantiacus. Simulated fed-batch conditions with xylose induced comparable levels of cellulases. These fed-batch conditions were adapted tomore » produce enzymes in 2 and 19 L bioreactors using xylose and xylose-rich hydrolysate from dilute acid pretreatment of corn stover. Enzymes from T. aurantiacus that were produced in the xylose-fed bioreactor demonstrated comparable performance in the saccharification of deacetylated, dilute acid-pretreated corn stover when compared to a commercial enzyme mixture at 50 °C. The T. aurantiacus enzymes retained this activity at of 60 °C while the commercial enzyme mixture was largely inactivated. CXylose induces both cellulase and xylanase production in T. aurantiacus and was used to produce enzymes at up to the 19 L bioreactor scale. The demonstration of induction by xylose-rich hydrolysate and saccharification of deacetylated, dilute acid-pretreated corn stover suggests a scenario to couple biomass pretreatment with onsite enzyme production in a biorefinery. This work further demonstrates the potential for T. aurantiacus as a thermophilic platform for cellulase development.« less

48 CFR 252.237-7011 - Preparation history.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Preparation history. 252.237-7011 Section 252.237-7011 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of...

48 CFR 252.237-7011 - Preparation history.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Preparation history. 252.237-7011 Section 252.237-7011 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of...

48 CFR 252.237-7011 - Preparation history.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Preparation history. 252.237-7011 Section 252.237-7011 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of...

48 CFR 252.237-7011 - Preparation history.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Preparation history. 252.237-7011 Section 252.237-7011 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of...

48 CFR 252.237-7011 - Preparation history.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Preparation history. 252.237-7011 Section 252.237-7011 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE CLAUSES AND FORMS SOLICITATION PROVISIONS AND CONTRACT CLAUSES Text of...

Effects of different cellulases on the release of phenolic acids from rice straw during saccharification.

PubMed

Xue, Yiyun; Wang, Xiahui; Chen, Xingxuan; Hu, Jiajun; Gao, Min-Tian; Li, Jixiang

2017-06-01

Effects of different cellulases on the release of phenolic acids from rice straw during saccharification were investigated in this study. All cellulases tested increased the contents of phenolic acids during saccharification. However, few free phenolic acids were detected, as they were present in conjugated form after saccharification when the cellulases from Trichoderma reesei, Trichoderma viride and Aspergillus niger were used. On the other hand, phenolic acids were present in free form when the Acremonium cellulolyticus cellulase was used. Assays of enzyme activity showed that, besides high cellulase activity, the A. cellulolyticus cellulase exhibited high feruloyl esterase (FAE) activity. A synergistic interaction between FAE and cellulase led to the increase in free phenolic acids, and thus an increase in antioxidative and antiradical activities of the phenolic acids. Moreover, a cost estimation demonstrated the feasibility of phenolic acids as value-added products to reduce the total production cost of ethanol. Copyright © 2017 Elsevier Ltd. All rights reserved.

48 CFR 1252.237-70 - Qualifications of contractor employees.

Code of Federal Regulations, 2010 CFR

2010-10-01

... contractor employees. 1252.237-70 Section 1252.237-70 Federal Acquisition Regulations System DEPARTMENT OF....237-70 Qualifications of contractor employees. As prescribed in (TAR) 48 CFR 1237.110(a), insert the following clause: Qualifications of Contractor Employees (APR 2005) a. Definitions. As used in this clause...

Modeling the Effect of pH and Temperature for Cellulases Immobilized on Enzymogel Nanoparticles.

PubMed

Samaratunga, Ashani; Kudina, Olena; Nahar, Nurun; Zakharchenko, Andrey; Minko, Sergiy; Voronov, Andriy; Pryor, Scott W

2015-06-01

Production costs of cellulosic biofuels can be lowered if cellulases are recovered and reused using particulate carriers that can be extracted after biomass hydrolysis. Such enzyme recovery was recently demonstrated using enzymogel nanoparticles with grafted polymer brushes loaded with cellulases. In this work, cellulase (NS50013) and β-glucosidase (Novozyme 188) were immobilized on enzymogels made of poly(acrylic acid) polymer brushes grafted to the surface of silica nanoparticles. Response surface methodology was used to model effects of pH and temperature on hydrolysis and recovery of free and attached enzymes. Hydrolysis yields using both enzymogels and free cellulase and β-glucosidase were highest at the maximum temperature tested, 50 °C. The optimal pH for cellulase enzymogels and free enzyme was 5.0 and 4.4, respectively, while both free β-glucosidase and enzymogels had an optimal pH near 4.4. Highest hydrolysis sugar concentrations with cellulase and β-glucosidase enzymogels were 69 and 53 % of those with free enzymes, respectively. Enzyme recovery using enzymogels decreased with increasing pH, but cellulase recovery remained greater than 88 % throughout the operating range of pH values less than 5.0 and was greater than 95 % at pH values below 4.3. Recovery of β-glucosidase enzymogels was not affected by temperature and had little impact on cellulase recovery.

49 CFR 237.51 - Railroad bridge engineers.

Code of Federal Regulations, 2013 CFR

2013-10-01

... engineering work to be performed: (1) Determine the forces and stresses in railroad bridges and bridge... 49 Transportation 4 2013-10-01 2013-10-01 false Railroad bridge engineers. 237.51 Section 237.51 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

49 CFR 237.51 - Railroad bridge engineers.

Code of Federal Regulations, 2012 CFR

2012-10-01

... engineering work to be performed: (1) Determine the forces and stresses in railroad bridges and bridge... 49 Transportation 4 2012-10-01 2012-10-01 false Railroad bridge engineers. 237.51 Section 237.51 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

49 CFR 237.51 - Railroad bridge engineers.

Code of Federal Regulations, 2014 CFR

2014-10-01

... engineering work to be performed: (1) Determine the forces and stresses in railroad bridges and bridge... 49 Transportation 4 2014-10-01 2014-10-01 false Railroad bridge engineers. 237.51 Section 237.51 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

49 CFR 237.51 - Railroad bridge engineers.

Code of Federal Regulations, 2010 CFR

2010-10-01

... engineering work to be performed: (1) Determine the forces and stresses in railroad bridges and bridge... 49 Transportation 4 2010-10-01 2010-10-01 false Railroad bridge engineers. 237.51 Section 237.51 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

49 CFR 237.51 - Railroad bridge engineers.

Code of Federal Regulations, 2011 CFR

2011-10-01

... engineering work to be performed: (1) Determine the forces and stresses in railroad bridges and bridge... 49 Transportation 4 2011-10-01 2011-10-01 false Railroad bridge engineers. 237.51 Section 237.51 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL RAILROAD ADMINISTRATION...

48 CFR 237.7001 - Method of acquisition.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Method of acquisition. 237.7001 Section 237.7001 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM... contract exists, use DD Form 1155, Order for Supplies or Services, to obtain mortuary services. ...

The prospects of cellulase-producing bacteria for the bioconversion of lignocellulosic biomass.

PubMed

Maki, Miranda; Leung, Kam Tin; Qin, Wensheng

2009-07-29

Lignocellulosic biomass is a renewable and abundant resource with great potential for bioconversion to value-added bioproducts. However, the biorefining process remains economically unfeasible due to a lack of biocatalysts that can overcome costly hurdles such as cooling from high temperature, pumping of oxygen/stirring, and, neutralization from acidic or basic pH. The extreme environmental resistance of bacteria permits screening and isolation of novel cellulases to help overcome these challenges. Rapid, efficient cellulase screening techniques, using cellulase assays and metagenomic libraries, are a must. Rare cellulases with activities on soluble and crystalline cellulose have been isolated from strains of Paenibacillus and Bacillus and shown to have high thermostability and/or activity over a wide pH spectrum. While novel cellulases from strains like Cellulomonas flavigena and Terendinibacter turnerae, produce multifunctional cellulases with broader substrate utilization. These enzymes offer a framework for enhancement of cellulases including: specific activity, thermalstability, or end-product inhibition. In addition, anaerobic bacteria like the clostridia offer potential due to species capable of producing compound multienzyme complexes called cellulosomes. Cellulosomes provide synergy and close proximity of enzymes to substrate, increasing activity towards crystalline cellulose. This has lead to the construction of designer cellulosomes enhanced for specific substrate activity. Furthermore, cellulosome-producing Clostridium thermocellum and its ability to ferment sugars to ethanol; its amenability to co-culture and, recent advances in genetic engineering, offer a promising future in biofuels. The exploitation of bacteria in the search for improved enzymes or strategies provides a means to upgrade feasibility for lignocellulosic biomass conversion, ultimately providing means to a 'greener' technology.

The prospects of cellulase-producing bacteria for the bioconversion of lignocellulosic biomass

PubMed Central

Maki, Miranda; Leung, Kam Tin; Qin, Wensheng

2009-01-01

Lignocellulosic biomass is a renewable and abundant resource with great potential for bioconversion to value-added bioproducts. However, the biorefining process remains economically unfeasible due to a lack of biocatalysts that can overcome costly hurdles such as cooling from high temperature, pumping of oxygen/stirring, and, neutralization from acidic or basic pH. The extreme environmental resistance of bacteria permits screening and isolation of novel cellulases to help overcome these challenges. Rapid, efficient cellulase screening techniques, using cellulase assays and metagenomic libraries, are a must. Rare cellulases with activities on soluble and crystalline cellulose have been isolated from strains of Paenibacillus and Bacillus and shown to have high thermostability and/or activity over a wide pH spectrum. While novel cellulases from strains like Cellulomonas flavigena and Terendinibacter turnerae, produce multifunctional cellulases with broader substrate utilization. These enzymes offer a framework for enhancement of cellulases including: specific activity, thermalstability, or end-product inhibition. In addition, anaerobic bacteria like the clostridia offer potential due to species capable of producing compound multienzyme complexes called cellulosomes. Cellulosomes provide synergy and close proximity of enzymes to substrate, increasing activity towards crystalline cellulose. This has lead to the construction of designer cellulosomes enhanced for specific substrate activity. Furthermore, cellulosome-producing Clostridium thermocellum and its ability to ferment sugars to ethanol; its amenability to co-culture and, recent advances in genetic engineering, offer a promising future in biofuels. The exploitation of bacteria in the search for improved enzymes or strategies provides a means to upgrade feasibility for lignocellulosic biomass conversion, ultimately providing means to a 'greener' technology. PMID:19680472

Xyloglucan oligosaccharides promote growth and activate cellulase: Evidence for a role of cellulase in cell expansion. [Pisum sativum L

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDougall, G.J.; Fry, S.C.

1990-07-01

Oligosaccharides produced by the action of fungal cellulase on xyloglucans promoted the elongation of etiolated pea (Pisum sativum L.) stem segments in a straight-growth bioassay designed for the determination of auxins. The oligosaccharides were most active at about 1 micromolar. We tested the relative growth-promoting activities of four HPLC-purified oligosaccharides which shared a common glucose{sub 4} {center dot} xylose{sub 3} (XG7) core. The substituted oligosaccharides XG8 (glucose{sub 4} {center dot} xylose{sub 3} {center dot} galactose) and XG9n (glucose{sub 4} {center dot} xylose{sub 3} {center dot} galactose{sub 2}) were more effective than XG7 itself and XG9 (glucose{sub 4} {center dot} xylose{submore » 3} {center dot} galactose {center dot} fucose). The same oligosaccharides also promoted the degradation, assayed viscometrically, of xyloglucan by an acidic cellulase from bean (Phaseolus vulgaris L.) leaves. The oligosaccharides were highly active at 10{sup {minus}4} molar, causing up to a fourfold increase in activity, but the effect was still detectable at 1 micromolar. Those oligosaccharides (XG8 and XG9n) which best promoted growth, stimulated cellulase activity to the greatest extent. The oligosaccharides did not stimulate the action of the cellulase in an assay based on the conversion of ({sup 3}H)xyloglucan to ethanol-soluble fragments. This suggests that the oligosaccharides enhanced the midchain hydrolysis of xyloglucan molecules (which would rapidly reduce the viscosity of the solution), at the expense of cleavage near the termini (which would yield ethanol-soluble products).« less

48 CFR 1852.237-72 - Access to Sensitive Information.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 6 2011-10-01 2011-10-01 false Access to Sensitive Information. 1852.237-72 Section 1852.237-72 Federal Acquisition Regulations System NATIONAL AERONAUTICS AND... and Clauses 1852.237-72 Access to Sensitive Information. As prescribed in 1837.203-72(a), insert the...

Solid-state fermentation for cellulase production by Pestalotiopsis versicolor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rao, M.N.A.; Mithal, B.M.; Thakkur, R.N.

1983-03-01

Solid-state fermentation (SSF) refers to the fermentation process on solid substrate without the presence of free liquid. It is found to be ideal when the organism is a fungus and the substrate is insoluble, like cellulose. Production of cellulase by SSF has been studied in detail by Toyama and Ogawa. It has been found that more concentrated enzyme preparations can be obtained by SSF than in liquid type since the enzyme gets diluted in the whole medium in liquid culture. In the present study, a plant pathogenic fungus Pestalotiopsis versicolor has been grown on various solid cultures of cellulosic substancesmore » and production of cellulase has been studied. Earlier, we had studied the production of cellulase by P. versicolor in liquid culture. (Refs. 7).« less

A possible water-soluble inducer for synthesis of cellulase in Aspergillus niger.

PubMed

Zhang, Jian-Guo; Li, Qi-Meng; Thakur, Kiran; Faisal, Shah; Wei, Zhao-Jun

2017-02-01

The synthesis of cellulase in filamentous fungi can be triggered by several inducers. In this study, a bamboo-shoot shell pretreated with Pleurotus ostreatus could promote the formation of cellulases in Aspergillus niger. Further identification, including UPLC-TOF-MS, ultrafiltration, and FT-IR, denoted that the soluble inducer was not a traditional disaccharide but a type of modified lignin polymer. This revelation may result in incipient strategies to ameliorate cellulase productivity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assimilating Text-Mining & Bio-Informatics Tools to Analyze Cellulase structures

NASA Astrophysics Data System (ADS)

Satyasree, K. P. N. V., Dr; Lalitha Kumari, B., Dr; Jyotsna Devi, K. S. N. V.; Choudri, S. M. Roy; Pratap Joshi, K.

2017-08-01

Text-mining is one of the best potential way of automatically extracting information from the huge biological literature. To exploit its prospective, the knowledge encrypted in the text should be converted to some semantic representation such as entities and relations, which could be analyzed by machines. But large-scale practical systems for this purpose are rare. But text mining could be helpful for generating or validating predictions. Cellulases have abundant applications in various industries. Cellulose degrading enzymes are cellulases and the same producing bacteria - Bacillus subtilis & fungus Pseudomonas putida were isolated from top soil of Guntur Dt. A.P. India. Absolute cultures were conserved on potato dextrose agar medium for molecular studies. In this paper, we presented how well the text mining concepts can be used to analyze cellulase producing bacteria and fungi, their comparative structures are also studied with the aid of well-establised, high quality standard bioinformatic tools such as Bioedit, Swissport, Protparam, EMBOSSwin with which a complete data on Cellulases like structure, constituents of the enzyme has been obtained.

Methods for Discovery of Novel Cellulosomal Cellulases Using Genomics and Biochemical Tools.

PubMed

Ben-David, Yonit; Dassa, Bareket; Bensoussan, Lizi; Bayer, Edward A; Moraïs, Sarah

2018-01-01

Cell wall degradation by cellulases is extensively explored owing to its potential contribution to biofuel production. The cellulosome is an extracellular multienzyme complex that can degrade the plant cell wall very efficiently, and cellulosomal enzymes are therefore of great interest. The cellulosomal cellulases are defined as enzymes that contain a dockerin module, which can interact with a cohesin module contained in multiple copies in a noncatalytic protein, termed scaffoldin. The assembly of the cellulosomal cellulases into the cellulosomal complex occurs via specific protein-protein interactions. Cellulosome systems have been described initially only in several anaerobic cellulolytic bacteria. However, owing to ongoing genome sequencing and metagenomic projects, the discovery of novel cellulosome-producing bacteria and the description of their cellulosomal genes have dramatically increased in the recent years. In this chapter, methods for discovery of novel cellulosomal cellulases from a DNA sequence by bioinformatics and biochemical tools are described. Their biochemical characterization is also described, including both the enzymatic activity of the putative cellulases and their assembly into mature designer cellulosomes.

9 CFR 2.37 - Federal research facilities.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 9 Animals and Animal Products 1 2012-01-01 2012-01-01 false Federal research facilities. 2.37... AGRICULTURE ANIMAL WELFARE REGULATIONS Research Facilities § 2.37 Federal research facilities. Each Federal research facility shall establish an Institutional Animal Care and Use Committee which shall have the same...

9 CFR 2.37 - Federal research facilities.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false Federal research facilities. 2.37... AGRICULTURE ANIMAL WELFARE REGULATIONS Research Facilities § 2.37 Federal research facilities. Each Federal research facility shall establish an Institutional Animal Care and Use Committee which shall have the same...

9 CFR 2.37 - Federal research facilities.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false Federal research facilities. 2.37... AGRICULTURE ANIMAL WELFARE REGULATIONS Research Facilities § 2.37 Federal research facilities. Each Federal research facility shall establish an Institutional Animal Care and Use Committee which shall have the same...

9 CFR 2.37 - Federal research facilities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Federal research facilities. 2.37... AGRICULTURE ANIMAL WELFARE REGULATIONS Research Facilities § 2.37 Federal research facilities. Each Federal research facility shall establish an Institutional Animal Care and Use Committee which shall have the same...

Effects of metal ions on the catalytic degradation of dicofol by cellulase.

PubMed

Zhai, Zihan; Yang, Ting; Zhang, Boya; Zhang, Jianbo

2015-07-01

A new technique whereby cellulase immobilized on aminated silica was applied to catalyze the degradation of dicofol, an organochlorine pesticide. In order to evaluate the performance of free and immobilized cellulase, experiments were carried out to measure the degradation efficiency. The Michaelis constant, Km, of the reaction catalyzed by immobilized cellulase was 9.16 mg/L, and the maximum reaction rate, Vmax, was 0.40 mg/L/min, while that of free cellulase was Km=8.18 mg/L, and Vmax=0.79 mg/L/min, respectively. The kinetic constants of catalytic degradation were calculated to estimate substrate affinity. Considering that metal ions may affect enzyme activity, the effects of different metal ions on the catalytic degradation efficiency were explored. The results showed that the substrate affinity decreased after immobilization. Monovalent metal ions had no effect on the reaction, while divalent metal ions had either positive or inhibitory effects, including activation by Mn2+, reversible competition with Cd2+, and irreversible inhibition by Pb2+. Ca2+ promoted the catalytic degradation of dicofol at low concentrations, but inhibited it at high concentrations. Compared with free cellulase, immobilized cellulase was affected less by metal ions. This work provided a basis for further studies on the co-occurrence of endocrine-disrupting chemicals and heavy metal ions in the environment. Copyright © 2015. Published by Elsevier B.V.

14 CFR 16.237 - Waiver of procedures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Waiver of procedures. 16.237 Section 16.237 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURAL RULES RULES OF... of this issue on appeal. (c) The parties may not by consent waive the obligation of the hearing...

14 CFR 16.237 - Waiver of procedures.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Waiver of procedures. 16.237 Section 16.237 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURAL RULES RULES OF... of this issue on appeal. (c) The parties may not by consent waive the obligation of the hearing...

14 CFR 16.237 - Waiver of procedures.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Waiver of procedures. 16.237 Section 16.237 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURAL RULES RULES OF... of this issue on appeal. (c) The parties may not by consent waive the obligation of the hearing...

14 CFR 16.237 - Waiver of procedures.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Waiver of procedures. 16.237 Section 16.237 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURAL RULES RULES OF... of this issue on appeal. (c) The parties may not by consent waive the obligation of the hearing...

14 CFR 16.237 - Waiver of procedures.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Waiver of procedures. 16.237 Section 16.237 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURAL RULES RULES OF... of this issue on appeal. (c) The parties may not by consent waive the obligation of the hearing...

Cellulase assisted synthesis of nano-silver and gold: Application as immobilization matrix for biocatalysis.

PubMed

Mishra, Abhijeet; Sardar, Meryam

2015-01-01

In the present study, we report in vitro synthesis of silver and gold nanoparticles (NPs) using cellulase enzyme in a single step reaction. Synthesized nanoparticles were characterized by UV-VIS spectroscopy, Dynamic Light Spectroscopy (DLS), Transmission Electron Microscopy (TEM), Energy-dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), Circular Dichroism (CD) and Fourier Transform Infrared Spectroscopy (FTIR). UV-visible studies shows absorption band at 415nm and 520nm for silver and gold NPs respectively due to surface plasmon resonance. Sizes of NPs as shown by TEM are 5-25nm for silver and 5-20nm for gold. XRD peaks confirmed about phase purity and crystallinity of silver and gold NPs. FTIR data shows presence of amide I peak on both the NPs. The cellulase assisted synthesized NPs were further exploited as immobilization matrix for cellulase enzyme. Thermal stability analysis reveals that the immobilized cellulase on synthesized NPs retained 77-80% activity as compared to free enzyme. While reusability data suggests immobilized cellulase can be efficiently used up to sixth cycles with minimum loss of enzyme activity. The secondary structural analysis of cellulase enzyme during the synthesis of NPs and also after immobilization of cellulase on these NPs was carried out by CD spectroscopy. Copyright © 2015 Elsevier B.V. All rights reserved.

Lignin-based polyoxyethylene ether enhanced enzymatic hydrolysis of lignocelluloses by dispersing cellulase aggregates.

PubMed

Lin, Xuliang; Qiu, Xueqing; Yuan, Long; Li, Zihao; Lou, Hongming; Zhou, Mingsong; Yang, Dongjie

2015-06-01

Water-soluble lignin-based polyoxyethylene ether (EHL-PEG), prepared from enzymatic hydrolysis lignin (EHL) and polyethylene glycol (PEG1000), was used to improve enzymatic hydrolysis efficiency of corn stover. The glucose yield of corn stover at 72h was increased from 16.7% to 70.1% by EHL-PEG, while increase in yield with PEG4600 alone was 52.3%. With the increase of lignin content, EHL-PEG improved enzymatic hydrolysis of microcrystalline cellulose more obvious than PEG4600. EHL-PEG could reduce at least 88% of the adsorption of cellulase on the lignin film measured by quartz crystal microbalance with dissipation monitoring (QCM-D), while reduction with PEG4600 was 43%. Cellulase aggregated at 1220nm in acetate buffer analyzed by dynamic light scattering. EHL-PEG dispersed cellulase aggregates and formed smaller aggregates with cellulase, thereby, reduced significantly nonproductive adsorption of cellulase on lignin and enhanced enzymatic hydrolysis of lignocelluloses. Copyright © 2015 Elsevier Ltd. All rights reserved.

Applicability evaluation of Deep Eutectic Solvents-Cellulase system for lignocellulose hydrolysis.

PubMed

Gunny, Ahmad Anas Nagoor; Arbain, Dachyar; Nashef, Enas Muen; Jamal, Parveen

2015-04-01

Deep Eutectic Solvents (DESs) have recently emerged as a new generation of ionic liquids for lignocellulose pretreatment. However, DESs contain salt components which tend to inactivate cellulase in the subsequent saccharification process. To alleviate this problem, it is necessary to evaluate the applicability of the DESs-Cellulase system. This was accomplished in the present study by first studying the stability of cellulase in the presence of selected DESs followed by applicability evaluation based on glucose production, energy consumption and kinetic performance. Results showed that the cellulase was able to retain more than 90% of its original activity in the presence of 10% (v/v) for glycerol based DES (GLY) and ethylene glycol based DES (EG). Furthermore, both DESs system exhibited higher glucose percentage enhancement and lower energy consumption as compared to diluted alkali system. Among the two DESs studied, EG showed comparatively better kinetic performance. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cellulase and Xylanase Production from Three Isolates of Indigenous Endophytic Fungi

NASA Astrophysics Data System (ADS)

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.

Reliable simultaneous zymographic method of characterization of cellulolytic enzymes from fungal cellulase complex.

PubMed

Dojnov, Biljana; Grujić, Marica; Vujčić, Zoran

2015-08-01

A method for zymographic detection of specific cellulases in a complex (endocellulase, exocellulase, and cellobiase) from crude fermentation extracts, after a single electrophoretic separation, is described in this paper. Cellulases were printed onto a membrane and, subsequently, substrate gel. Cellobiase isoforms were detected on the membrane using esculine as substrate, endocellulase isoforms on substrate gel with copolymerized carboxymethyl cellulose (CMC), while exocellulase isoforms were detected in electrophoresis gel with 4-methylumbelliferyl-β-d-cellobioside (MUC). This can be a useful additional tool for monitoring and control of fungal cellulase production in industrial processes and fundamental research, screening for particular cellulase producers, or testing of new lignocellulose substrates. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synergistic and Dose-Controlled Regulation of Cellulase Gene Expression in Penicillium oxalicum.

PubMed

Li, Zhonghai; Yao, Guangshan; Wu, Ruimei; Gao, Liwei; Kan, Qinbiao; Liu, Meng; Yang, Piao; Liu, Guodong; Qin, Yuqi; Song, Xin; Zhong, Yaohua; Fang, Xu; Qu, Yinbo

2015-09-01

Filamentous fungus Penicillium oxalicum produces diverse lignocellulolytic enzymes, which are regulated by the combinations of many transcription factors. Here, a single-gene disruptant library for 470 transcription factors was constructed and systematically screened for cellulase production. Twenty transcription factors (including ClrB, CreA, XlnR, Ace1, AmyR, and 15 unknown proteins) were identified to play putative roles in the activation or repression of cellulase synthesis. Most of these regulators have not been characterized in any fungi before. We identified the ClrB, CreA, XlnR, and AmyR transcription factors as critical dose-dependent regulators of cellulase expression, the core regulons of which were identified by analyzing several transcriptomes and/or secretomes. Synergistic and additive modes of combinatorial control of each cellulase gene by these regulatory factors were achieved, and cellulase expression was fine-tuned in a proper and controlled manner. With one of these targets, the expression of the major intracellular β-glucosidase Bgl2 was found to be dependent on ClrB. The Bgl2-deficient background resulted in a substantial gene activation by ClrB and proved to be closely correlated with the relief of repression mediated by CreA and AmyR during cellulase induction. Our results also signify that probing the synergistic and dose-controlled regulation mechanisms of cellulolytic regulators and using it for reconstruction of expression regulation network (RERN) may be a promising strategy for cellulolytic fungi to develop enzyme hyper-producers. Based on our data, ClrB was identified as focal point for the synergistic activation regulation of cellulase expression by integrating cellulolytic regulators and their target genes, which refined our understanding of transcriptional-regulatory network as a "seesaw model" in which the coordinated regulation of cellulolytic genes is established by counteracting activators and repressors.

Synergistic and Dose-Controlled Regulation of Cellulase Gene Expression in Penicillium oxalicum

PubMed Central

Li, Zhonghai; Yao, Guangshan; Wu, Ruimei; Gao, Liwei; Kan, Qinbiao; Liu, Meng; Yang, Piao; Liu, Guodong; Qin, Yuqi; Song, Xin; Zhong, Yaohua; Fang, Xu; Qu, Yinbo

2015-01-01

Filamentous fungus Penicillium oxalicum produces diverse lignocellulolytic enzymes, which are regulated by the combinations of many transcription factors. Here, a single-gene disruptant library for 470 transcription factors was constructed and systematically screened for cellulase production. Twenty transcription factors (including ClrB, CreA, XlnR, Ace1, AmyR, and 15 unknown proteins) were identified to play putative roles in the activation or repression of cellulase synthesis. Most of these regulators have not been characterized in any fungi before. We identified the ClrB, CreA, XlnR, and AmyR transcription factors as critical dose-dependent regulators of cellulase expression, the core regulons of which were identified by analyzing several transcriptomes and/or secretomes. Synergistic and additive modes of combinatorial control of each cellulase gene by these regulatory factors were achieved, and cellulase expression was fine-tuned in a proper and controlled manner. With one of these targets, the expression of the major intracellular β-glucosidase Bgl2 was found to be dependent on ClrB. The Bgl2-deficient background resulted in a substantial gene activation by ClrB and proved to be closely correlated with the relief of repression mediated by CreA and AmyR during cellulase induction. Our results also signify that probing the synergistic and dose-controlled regulation mechanisms of cellulolytic regulators and using it for reconstruction of expression regulation network (RERN) may be a promising strategy for cellulolytic fungi to develop enzyme hyper-producers. Based on our data, ClrB was identified as focal point for the synergistic activation regulation of cellulase expression by integrating cellulolytic regulators and their target genes, which refined our understanding of transcriptional-regulatory network as a “seesaw model” in which the coordinated regulation of cellulolytic genes is established by counteracting activators and repressors. PMID:26360497

Cellulase retention and sugar removal by membrane ultrafiltration during lignocellulosic biomass hydrolysis.

PubMed

Knutsen, Jeffrey S; Davis, Robert H

2004-01-01

Technologies suitable for the separation and reuse of cellulase enzymes during the enzymatic saccharification of pretreated corn stover are investigated to examine the economic and technical viability of processes that promote cellulase reuse while removing inhibitory reaction products such as glucose and cellobiose. The simplest and most suitable separation is a filter with relatively large pores on the order of 20-25 mm that retains residual corn stover solids while passing reaction products such as glucose and cellobiose to form a sugar stream for a variety of end uses. Such a simple separation is effective because cellulase remains bound to the residual solids. Ultrafiltration using 50-kDa polyethersulfone membranes to recover cellulase enzymes in solution was shown not to enhance further the saccharification rate or overall conversion. Instead, it appears that the necessary cellulase enzymes, including beta-glucosidase, are tightly bound to the substrate; when fresh corn stover is contacted with highly washed residual solids, without the addition of fresh enzymes, glucose is generated at a high rate. When filtration was applied multiple times, the concentration of inhibitory reaction products such as glucose and cellobiose was reduced from 70 to 10 g/L. However, an enhanced saccharification performance was not observed, most likely because the concentration of the inhibitory products remained too high. Further reduction in the product concentration was not investigated, because it would make the reaction unnecessarily complex and result in a product stream that is much too dilute to be useful. Finally, an economic analysis shows that reuse of cellulase can reduce glucose production costs, especially when the enzyme price is high. The most economic performance is shown to occur when the cellulase enzyme is reused and a small amount of fresh enzyme is added after each separation step to replace lost or deactivated enzyme.

Recovery and reuse of cellulase catalyst in an exzymatic cellulose hydrolysis process

DOEpatents

Woodward, Jonathan

1989-01-01

A process for recovering cellulase from the hydrolysis of cellulose, and reusing it in subsequent hydrolyois procedures. The process utilizes a commercial adsorbent that efficiently removes cellulase from reaction products which can be easily removed by simple decantation.

Development of a low-cost cellulase production process using Trichoderma reesei for Brazilian biorefineries.

PubMed

Ellilä, Simo; Fonseca, Lucas; Uchima, Cristiane; Cota, Junio; Goldman, Gustavo Henrique; Saloheimo, Markku; Sacon, Vera; Siika-Aho, Matti

2017-01-01

During the past few years, the first industrial-scale cellulosic ethanol plants have been inaugurated. Although the performance of the commercial cellulase enzymes used in this process has greatly improved over the past decade, cellulases still represent a very significant operational cost. Depending on the region, transport of cellulases from a central production facility to a biorefinery may significantly add to enzyme cost. The aim of the present study was to develop a simple, cost-efficient cellulase production process that could be employed locally at a Brazilian sugarcane biorefinery. Our work focused on two main topics: growth medium formulation and strain improvement. We evaluated several Brazilian low-cost industrial residues for their potential in cellulase production. Among the solid residues evaluated, soybean hulls were found to display clearly the most desirable characteristics. We engineered a Trichoderma reesei strain to secrete cellulase in the presence of repressing sugars, enabling the use of sugarcane molasses as an additional carbon source. In addition, we added a heterologous β-glucosidase to improve the performance of the produced enzymes in hydrolysis. Finally, the addition of an invertase gene from Aspegillus niger into our strain allowed it to consume sucrose from sugarcane molasses directly. Preliminary cost analysis showed that the overall process can provide for very low-cost enzyme with good hydrolysis performance on industrially pre-treated sugarcane straw. In this study, we showed that with relatively few genetic modifications and the right growth medium it is possible to produce considerable amounts of well-performing cellulase at very low cost in Brazil using T. reesei . With further enhancements and optimization, such a system could provide a viable alternative to delivered commercial cellulases.

The Putative Cellodextrin Transporter-like Protein CLP1 Is Involved in Cellulase Induction in Neurospora crassa*

PubMed Central

Cai, Pengli; Wang, Bang; Ji, Jingxiao; Jiang, Yongsheng; Wan, Li; Tian, Chaoguang; Ma, Yanhe

2015-01-01

Neurospora crassa recently has become a novel system to investigate cellulase induction. Here, we discovered a novel membrane protein, cellodextrin transporter-like protein 1 (CLP1; NCU05853), a putative cellodextrin transporter-like protein that is a critical component of the cellulase induction pathway in N. crassa. Although CLP1 protein cannot transport cellodextrin, the suppression of cellulase induction by this protein was discovered on both cellobiose and Avicel. The co-disruption of the cellodextrin transporters cdt2 and clp1 in strain Δ3βG formed strain CPL7. With induction by cellobiose, cellulase production was enhanced 6.9-fold in CPL7 compared with Δ3βG. We also showed that the suppression of cellulase expression by CLP1 occurred by repressing the expression of cellodextrin transporters, particularly cdt1 expression. Transcriptome analysis of the hypercellulase-producing strain CPL7 showed that the cellulase expression machinery was dramatically stimulated, as were the cellulase enzyme genes including the inducer transporters and the major transcriptional regulators. PMID:25398875

The putative cellodextrin transporter-like protein CLP1 is involved in cellulase induction in Neurospora crassa.

PubMed

Cai, Pengli; Wang, Bang; Ji, Jingxiao; Jiang, Yongsheng; Wan, Li; Tian, Chaoguang; Ma, Yanhe

2015-01-09

Neurospora crassa recently has become a novel system to investigate cellulase induction. Here, we discovered a novel membrane protein, cellodextrin transporter-like protein 1 (CLP1; NCU05853), a putative cellodextrin transporter-like protein that is a critical component of the cellulase induction pathway in N. crassa. Although CLP1 protein cannot transport cellodextrin, the suppression of cellulase induction by this protein was discovered on both cellobiose and Avicel. The co-disruption of the cellodextrin transporters cdt2 and clp1 in strain Δ3βG formed strain CPL7. With induction by cellobiose, cellulase production was enhanced 6.9-fold in CPL7 compared with Δ3βG. We also showed that the suppression of cellulase expression by CLP1 occurred by repressing the expression of cellodextrin transporters, particularly cdt1 expression. Transcriptome analysis of the hypercellulase-producing strain CPL7 showed that the cellulase expression machinery was dramatically stimulated, as were the cellulase enzyme genes including the inducer transporters and the major transcriptional regulators. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Alkaline hydrogen peroxide pretreatment of cashew apple bagasse for ethanol production: study of parameters.

PubMed

Correia, Jessyca Aline da Costa; Júnior, José Edvan Marques; Gonçalves, Luciana Rocha B; Rocha, Maria Valderez Ponte

2013-07-01

The alkaline hydrogen peroxide (AHP) pretreatment of cashew apple bagasse (CAB) was evaluated based on the conversion of the resultant cellulose into glucose. The effects of the concentration of hydrogen peroxide at pH 11.5, the biomass loading and the pretreatment duration performed at 35°C and 250 rpm were evaluated after the subsequent enzymatic saccharification of the pretreated biomass using a commercial cellulase enzyme. The CAB used in this study contained 20.56 ± 2.19% cellulose, 10.17 ± 0.89% hemicellulose and 35.26 ± 0.90% lignin. The pretreatment resulted in a reduced lignin content in the residual solids. Increasing the H2O2 concentration (0-4.3% v/v) resulted in a higher rate of enzymatic hydrolysis. Lower biomass loadings gave higher glucose yields. In addition, no measurable furfural and hydroxymethyl furfural were produced in the liquid fraction during the pretreatment. The results show that alkaline hydrogen peroxide is effective for the pretreatment of CAB. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Accelerating effects of cellulase in the removal of denture adhesives from acrylic denture bases.

PubMed

Harada-Hada, Kae; Mimura, Sumiyo; Hong, Guang; Hashida, Tatsumi; Abekura, Hitoshi; Murata, Hiroshi; Nishimura, Masahiro; Nikawa, Hiroki

2017-04-01

Studies of effective methods for the easy removal of denture adhesives from a denture base are not well represented in the literature. We previously assessed the removability of denture adhesives by immersing within denture cleaners, showing that some cleaners have a weak effect, insufficiently effective in daily use. In this study, we prepared a cellulase, as a potential component for denture adhesive removers, and we examined whether the addition of cellulase to denture cleaners is effective in the removal of cream denture adhesives. We prepared the cellulase Meicelase as one component for the liquefaction of denture adhesives. We used two denture cleaners and two cream adhesives. After the immersion of plates in sample solutions, we evaluated the area of the sample plate still covered with adhesives. Biofilm removal assay was also performed using denture cleaners containing cellulase. The addition of cellulase accelerated the removal of cream adhesives in immersion experiments to a rate faster than that of water and denture cleaners. However, it did not influence the removability of Candida albicans biofilms from acrylic resin specimens. Cellulase hastened the liquefaction of cream adhesives. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Novel Magnetic Cross-Linked Cellulase Aggregates with a Potential Application in Lignocellulosic Biomass Bioconversion.

PubMed

Jia, Junqi; Zhang, Weiwei; Yang, Zengjie; Yang, Xianling; Wang, Na; Yu, Xiaoqi

2017-02-10

The utilization of renewable biomass resources to produce high-value chemicals by enzymatic processes is beneficial for alternative energy production, due to the accelerating depletion of fossil fuels. As immobilization techniques can improve enzyme stability and reusability, a novel magnetic cross-linked cellulase aggregate has been developed and applied for biomass bioconversion. The crosslinked aggregates could purify and immobilize enzymes in a single operation, and could then be combined with magnetic nanoparticles (MNPs), which provides easy separation of the materials. The immobilized cellulase showed a better activity at a wider temperature range and pH values than that of the free cellulase. After six cycles of consecutive reuse, the immobilized cellulase performed successful magnetic separation and retained 74% of its initial activity when carboxylmethyl cellulose (CMC) was used as the model substrate. Furthermore, the structure and morphology of the immobilized cellulase were studied by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Moreover, the immobilized cellulase was shown to hydrolyze bamboo biomass with a yield of 21%, and was re-used in biomass conversion up to four cycles with 38% activity retention, which indicated that the immobilized enzyme has good potential for biomass applications.

Gene Cloning and Expression of Cellulase of Bacillus amyloliquefaciens Isolated from the Cecum of Goose.

PubMed

Sun, Linghong; Cao, Jiangyan; Liu, Ying; Wang, Junjie; Guo, Panpan; Wang, Zaigui

2017-01-02

A kind of bacteria secreting cellulase and showing probiotic attributes was isolated from the cecum of goose and identified as Bacillus amyloliquefaciens by analysis of 16S rRNA gene sequence and named as B. amyloliquefaciens S1. In vitro assays, the enzymatic activity of the strain was determined by the reducing-sugar method, and the proper culture conditions of producing cellulase and some properties of the cellulase were investigated. The cultural mixture of the bacteria had a high cellulase activity of 1.25 U/mL. In order to improve the utilization rate of the cellulase, some properties of the cellulase were studied. The best reaction pH of the enzymes was 7.0 and the optimum reaction temperature was 60°C. The enzyme was a kind of neutral cellulase that possessing strong resistance against heat and acidity. It showed high activity to absorbent cotton, soybean meal, and filter paper. Meanwhile, a gene encoding a kind of cellulase was cloned and prokaryotic expressed in Escherichia coli. The gene had 1500 bp in length, encoding a protein of 55 kDa, which was confirmed by SDS-PAGE and Western blotting. This study explored the possibility of degrading ability of bacteria with its probiotic attributes to enhance digestibility of the feed and gut health of animal. It also provided some basis for its further functional analysis and practical application as a microbial preparation for the breeding.

42 CFR 456.237 - Notification of adverse decision.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 4 2010-10-01 2010-10-01 false Notification of adverse decision. 456.237 Section 456.237 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL ASSISTANCE PROGRAMS UTILIZATION CONTROL Utilization Control: Mental Hospitals...

Recovery and reuse of cellulase catalyst in an enzymatic cellulose hydrolysis process

DOEpatents

Woodward, J.

1987-09-18

A process for recovering cellulase from the hydrolysis of cellulose, and reusing it in subsequent hydrolyois procedures. The process utilizes a commercial adsorbent that efficiently removes cellulase from reaction products which can be easily removed by simple decantation. 1 fig., 4 tabs.

A liquid crystal-based sensor for the simple and sensitive detection of cellulase and cysteine.

PubMed

Wang, Yi; Hu, Qiongzheng; Tian, Tongtong; Gao, Yan'an; Yu, Li

2016-11-01

A liquid crystal (LC)-based sensor, which is capable of monitoring enzymatic activity at the aqueous/LC interface and detecting cellulase and cysteine (Cys), was herein reported. When functionalized with a surfactant, dodecyl β-d-glucopyranoside, the 4-cyano-4'-pentylbiphenyl (5CB) displays a dark-to-bright transition in the optical appearance for cellulase. We attribute this change to the orientational transition of LCs, as a result of enzymatic hydrolysis between cellulase and surfactant. Furthermore, by adding cellulase and Cu(2+), our surfactant-LCs system performs an interesting ability to detect Cys, even though Cys could not interact with surfactant or LC directly. Alternatively, through the strong binding between Cys and Cu(2+), cellulase was able to hydrolyze surfactant in the presence of Cu(2+), leading to the transition of LCs from dark to bright. The detection limit of the LC sensor was around 1×10(-5)mg/mL and 82.5μM for cellulase and Cys, respectively. The LC-based sensor may contribute to the development of low-cost, expedient, and label-free detection for cellulase and Cys and the design strategy may also provide a novel way for detecting multiple analytes. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of Ten Wild Nigerian Mushrooms for Amylase and Cellulase Activities

PubMed Central

Adeoyo, Olusegun Richard

2011-01-01

Amylases and cellulases are important enzymes that can be utilized for various biological activities. Ten different wild Nigerian mushrooms (Agaricus blazei, Agaricus sp., Corilopsis occidentalis, Coriolus versicolor, Termitomyces clypeatus, Termitomyces globulus, Pleurotus tuber-regium, Podoscypha bolleana, Pogonomyces hydnoides, and Nothopanus hygrophanus) were assayed for production of these secondary metabolites. The results revealed that most of the tested wild fungi demonstrated very good amylase and cellulase activities. With the incorporation of carboxymethyl-cellulose (a carbon source) into the culture medium, Agaricus blazei had the highest amylolytic activity of 0.60 unit/mL (at 25℃, pH 6.8). This was followed in order by P. tuber-regium and Agaricus sp. with 0.42 and 0.39 unit/mL, respectively (p ≤ 0.05). Maltose and sucrose supplementation into the submerged liquid medium made N. hygrophanus and P. hydnoides to exhibit very low amylase activities of 0.09 and 0.11 unit/mL, respectively. Introducing peptone (an organic nitrogen source) into the basal medium enhanced the ability of C. versicolor to produce a cellulase value of 0.74 unit/mL. Other organic nitrogen sources that supported good cellulase activities were yeast extract and urea. Sodium nitrate (inorganic nitrogen source) generally inhibited cellulase production in all mushrooms. The best carbon source was carboxymethyl-cellulose, which promoted very high cellulase activity of 0.67 unit/mL in C. versicolor, which was followed in order by P. tuber-regium, T. chypeatus, and C. occidentalis (p ≤ 0.05). Sucrose was the poorest carbon compound, supporting the lowest values of 0.01, 0.01, and 0.14 unit/mL in P. hydnoides, A. blazei, and Agaricus sp., respectively. PMID:22783085

Biochemical Characterization of Extracellular Cellulase from Tuber maculatum Mycelium Produced Under Submerged Fermentation.

PubMed

Bedade, Dattatray K; Singhal, Rekha S; Turunen, Ossi; Deska, Jan; Shamekh, Salem

2017-02-01

Interaction of truffle mycelium with the host plant involves the excretion of extracellular enzymes. The ability of Tuber maculatum mycelium to produce an extracellular cellulase during submerged fermentation was demonstrated for the first time. T. maculatum mycelia were isolated and tested for extracellular cellulase production at variable pH on solid agar medium, and the highest activity was observed at pH 7.0. Furthermore, T. maculatum was subjected to submerged fermentation in basal salt medium for cellulase production. Under optimized conditions using sodium carboxymethyl cellulose (0.5 % w/v) as carbon source and an initial pH of 7.0, the enzyme production yielded 1.70 U/mL of cellulase in the cell-free supernatant after 7 days of incubation time. The optimum of the obtained cellulase's activity was at pH 5.0 and a temperature of 50 °C. The enzyme showed good thermostability at 50 °C by retaining 99 % of its maximal activity over an incubation time of 100 min. The cellulase activity was inhibited by Fe 2+ and slightly activated by Mn 2+ and Cu 2+ at 1 mM concentration. The results indicated that truffle mycelium is utilizing cellulosic energy source in the root system, and the optimal conditions are those existing in the acidic Finnish soil.

49 CFR 237.101 - Scheduling of bridge inspections.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Scheduling of bridge inspections. 237.101 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.101 Scheduling of bridge inspections. (a) Each bridge management program shall include a provision for scheduling an...

49 CFR 237.101 - Scheduling of bridge inspections.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Scheduling of bridge inspections. 237.101 Section... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.101 Scheduling of bridge inspections. (a) Each bridge management program shall include a provision for scheduling an...

Improvement of ethanol production from crystalline cellulose via optimizing cellulase ratios in cellulolytic Saccharomyces cerevisiae.

PubMed

Liu, Zhuo; Inokuma, Kentaro; Ho, Shih-Hsin; den Haan, Riaan; van Zyl, Willem H; Hasunuma, Tomohisa; Kondo, Akihiko

2017-06-01

Crystalline cellulose is one of the major contributors to the recalcitrance of lignocellulose to degradation, necessitating high dosages of cellulase to digest, thereby impeding the economic feasibility of cellulosic biofuels. Several recombinant cellulolytic yeast strains have been developed to reduce the cost of enzyme addition, but few of these strains are able to efficiently degrade crystalline cellulose due to their low cellulolytic activities. Here, by combining the cellulase ratio optimization with a novel screening strategy, we successfully improved the cellulolytic activity of a Saccharomyces cerevisiae strain displaying four different synergistic cellulases on the cell surface. The optimized strain exhibited an ethanol yield from Avicel of 57% of the theoretical maximum, and a 60% increase of ethanol titer from rice straw. To our knowledge, this work is the first optimization of the degradation of crystalline cellulose by tuning the cellulase ratio in a cellulase cell-surface display system. This work provides key insights in engineering the cellulase cocktail in a consolidated bioprocessing yeast strain. Biotechnol. Bioeng. 2017;114: 1201-1207. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

48 CFR 2152.237-70 - Continuity of services.

Code of Federal Regulations, 2010 CFR

2010-10-01

.... 2152.237-70 Section 2152.237-70 Federal Acquisition Regulations System OFFICE OF PERSONNEL MANAGEMENT... Government or another Contractor, may continue them. The Contractor agrees to furnish phase-in training and...) The Contractor shall, upon the Contracting Officer's written notice, (1) furnish phase-in and phase...

49 CFR 199.237 - Other alcohol-related conduct.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 3 2010-10-01 2010-10-01 false Other alcohol-related conduct. 199.237 Section 199... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY DRUG AND ALCOHOL TESTING Alcohol Misuse Prevention Program § 199.237 Other alcohol-related conduct. (a) No operator shall...

49 CFR 199.237 - Other alcohol-related conduct.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 3 2011-10-01 2011-10-01 false Other alcohol-related conduct. 199.237 Section 199... MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) PIPELINE SAFETY DRUG AND ALCOHOL TESTING Alcohol Misuse Prevention Program § 199.237 Other alcohol-related conduct. (a) No operator shall...

48 CFR 3452.237-71 - Services of consultants.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 7 2010-10-01 2010-10-01 false Services of consultants. 3452.237-71 Section 3452.237-71 Federal Acquisition Regulations System DEPARTMENT OF EDUCATION... set forth, $150, exclusive of travel costs, or if the services of any consultant under this contract...

A multipurpose immobilized biocatalyst with pectinase, xylanase and cellulase activities

PubMed Central

Dalal, Sohel; Sharma, Aparna; Gupta, Munishwar Nath

2007-01-01

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. PMID:17880745

A multipurpose immobilized biocatalyst with pectinase, xylanase and cellulase activities.

PubMed

Dalal, Sohel; Sharma, Aparna; Gupta, Munishwar Nath

2007-06-08

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. 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 V(max)/K(m) 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 degrees C, 60 degrees C and 70 degrees 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. 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.

Preparation, characterisation and use for antioxidant oligosaccharides of a cellulase from abalone (Haliotis discus hannai) viscera.

PubMed

Tao, Zhi-Peng; Sun, Le-Chang; Qiu, Xu-Jian; Cai, Qiu-Feng; Liu, Guang-Ming; Su, Wen-Jin; Cao, Min-Jie

2016-07-01

In China, abalone (Haliotis discus hannai) production is growing annually. During industrial processing, the viscera, which are abundant of cellulase, are usually discarded or processed into low-value feedstuff. Thus, it is of interest to obtain cellulase from abalone viscera and investigate its application for preparation of functional oligosaccharides. A cellulase was purified from the hepatopancreas of abalone by ammonium sulfate precipitation and two-steps column chromatography. The molecular weight of the cellulase was 45 kDa on SDS-PAGE. Peptide mass fingerprinting analysis yielded 103 amino acid residues, which were identical to cellulases from other species of abalone. Substrate specificity analysis indicated that the cellulase is an endo-1,4-β-glucanase. Hydrolysis of seaweed Porphyra haitanensis polysaccharides by the enzyme produced oligosaccharides with degree of polymerisation of two to four, whose monosaccharide composition was 58% galactose, 4% glucose and 38% xylose. The oligosaccharides revealed 2,2'-diphenyl-1-picrylhydrazyl free radical as well as hydrogen peroxide scavenging activity. It is feasible and meaningful to utilise cellulase from the viscera of abalone for preparation of functional oligosaccharides. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

30 CFR 23.7 - Specific requirements for approval.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., EVALUATION, AND APPROVAL OF MINING PRODUCTS TELEPHONES AND SIGNALING DEVICES § 23.7 Specific requirements for... apply. (g) Line powered telephones and signaling devices or systems shall be equipped with standby power... 30 Mineral Resources 1 2013-07-01 2013-07-01 false Specific requirements for approval. 23.7...

30 CFR 23.7 - Specific requirements for approval.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., EVALUATION, AND APPROVAL OF MINING PRODUCTS TELEPHONES AND SIGNALING DEVICES § 23.7 Specific requirements for... apply. (g) Line powered telephones and signaling devices or systems shall be equipped with standby power... 30 Mineral Resources 1 2014-07-01 2014-07-01 false Specific requirements for approval. 23.7...

30 CFR 23.7 - Specific requirements for approval.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., EVALUATION, AND APPROVAL OF MINING PRODUCTS TELEPHONES AND SIGNALING DEVICES § 23.7 Specific requirements for... apply. (g) Line powered telephones and signaling devices or systems shall be equipped with standby power... 30 Mineral Resources 1 2012-07-01 2012-07-01 false Specific requirements for approval. 23.7...

Bioethanol potentials of corn cob hydrolysed using cellulases of Aspergillus niger and Penicillium decumbens.

PubMed

Saliu, Bolanle Kudirat; Sani, Alhassan

2012-01-01

Corn cob is a major component of agricultural and domestic waste in many parts of the world. It is composed mainly of cellulose which can be converted to energy in form of bioethanol as an efficient and effective means of waste management. Production of cellulolytic enzymes were induced in the fungi Aspergillus niger and Penicillium decumbens by growing them in mineral salt medium containing alkali pre-treated and untreated corn cobs. The cellulases were characterized and partially purified. Alkali pre-treated corn cobs were hydrolysed with the partially purified cellulases and the product of hydrolysis was fermented using the yeast saccharomyces cerevisae to ethanol. Cellulases of A. niger produced higher endoglucanase and exoglucanase activity (0.1698 IU ml(-1) and 0.0461 FPU ml(-1)) compared to that produced by P. decumbens (0.1111 IU ml(-1) and 0.153 FPU ml(-1)). Alkali pre-treated corn cob hydrolysed by cellulases of A. niger yielded 7.63 mg ml(-1) sugar which produced 2.67 % (v/v) ethanol on fermentation. Ethanol yield of the hydrolysates of corn cob by cellulases of P. decumbens was much lower at 0.56 % (v/v). Alkali pre-treated corn cob, hydrolysed with cellulases of A. niger is established as suitable feedstock for bioethanol production.

48 CFR 237.7302 - General.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Development Laboratories 237.7302 General. Generally, agencies will acquire services of students at institutions of higher learning by contract between a nonprofit organization employing the student and the...

Evaluation of nanoparticle-immobilized cellulase for improved ethanol yield in simultaneous saccharification and fermentation reactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lupoi, Jason; Smith, Emily

2011-12-01

Ethanol yields were 2.1 (P = 0.06) to 2.3 (P = 0.01) times higher in simultaneous saccharification and fermentation (SSF) reactions of microcrystalline cellulose when cellulase was physisorbed on silica nanoparticles compared to enzyme in solution. In SSF reactions, cellulose is hydrolyzed to glucose by cellulase while yeast simultaneously ferments glucose to ethanol. The 35 C temperature and the presence of ethanol in SSF reactions are not optimal conditions for cellulase. Immobilization onto solid supports can stabilize the enzyme and promote activity at non-optimum reaction conditions. Mock SSF reactions that did not contain yeast were used to measure saccharification productsmore » and identify the mechanism for the improved ethanol yield using immobilized cellulase. Cellulase adsorbed to 40 nm silica nanoparticles produced 1.6 times (P = 0.01) more glucose than cellulase in solution in 96 h at pH 4.8 and 35 C. There was no significant accumulation (<250 {mu}g) of soluble cellooligomers in either the solution or immobilized enzyme reactions. This suggests that the mechanism for the immobilized enzyme's improved glucose yield compared to solution enzyme is the increased conversion of insoluble cellulose hydrolysis products to soluble cellooligomers at 35 C and in the presence of ethanol. The results show that silica-immobilized cellulase can be used to produce increased ethanol yields in the conversion of lignocellulosic materials by SSF.« less

Kinetic studies on batch cultivation of Trichoderma reesei and application to enhance cellulase production by fed-batch fermentation.

PubMed

Ma, Lijuan; Li, Chen; Yang, Zhenhua; Jia, Wendi; Zhang, Dongyuan; Chen, Shulin

2013-07-20

Reducing the production cost of cellulase as the key enzyme for cellulose hydrolysis to fermentable sugars remains a major challenge for biofuel production. Because of the complexity of cellulase production, kinetic modeling and mass balance calculation can be used as effective tools for process design and optimization. In this study, kinetic models for cell growth, substrate consumption and cellulase production in batch fermentation were developed, and then applied in fed-batch fermentation to enhance cellulase production. Inhibition effect of substrate was considered and a modified Luedeking-Piret model was developed for cellulase production and substrate consumption according to the growth characteristics of Trichoderma reesei. The model predictions fit well with the experimental data. Simulation results showed that higher initial substrate concentration led to decrease of cellulase production rate. Mass balance and kinetic simulation results were applied to determine the feeding strategy. Cellulase production and its corresponding productivity increased by 82.13% after employing the proper feeding strategy in fed-batch fermentation. This method combining mathematics and chemometrics by kinetic modeling and mass balance can not only improve cellulase fermentation process, but also help to better understand the cellulase fermentation process. The model development can also provide insight to other similar fermentation processes. Copyright © 2013 Elsevier B.V. All rights reserved.

Cellulases: Role in Lignocellulosic Biomass Utilization.

PubMed

Soni, Sanjeev Kumar; Sharma, Amita; Soni, Raman

2018-01-01

Rapid depletion of fossil fuels worldwide presents a dire situation demanding a potential replacement to surmount the current energy crisis. Lignocellulose presents a logical candidate to be exploited at industrial scale owing to its vast availability, inexpensive and renewable nature. Microbial degradation of lignocellulosic biomass is a lucrative, sustainable, and promising approach to obtain valuable commercial commodities at gigantic scale. The enzymatic hydrolysis involving cellulases is fundamental to all the technologies needed to transform lignocellulosic biomass to valuable industry relevant products. Cellulases have enormous potential to utilize cellulosic biomass, thus reducing environmental stress in addition to production of commodity chemicals resolving the current challenge to meet the energy needs globally. The substitution of petroleum-based fuels with bio-based fuels is the subject of thorough research establishing biofuel production as the future technology to achieve a sustainable, eco-friendly society with a zero waste approach.

42 CFR 456.237 - Notification of adverse decision.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 42 Public Health 4 2011-10-01 2011-10-01 false Notification of adverse decision. 456.237 Section 456.237 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... § 456.236 (f) through (h) is sent to— (a) The hospital administrator; (b) The attending or staff...

Screening for Cellulase Encoding Clones in Metagenomic Libraries.

PubMed

Ilmberger, Nele; Streit, Wolfgang R

2017-01-01

For modern biotechnology there is a steady need to identify novel enzymes. In biotechnological applications, however, enzymes often must function under extreme and nonnatural conditions (i.e., in the presence of solvents, high temperature and/or at extreme pH values). Cellulases have many industrial applications from the generation of bioethanol, a realistic long-term energy source, to the finishing of textiles. These industrial processes require cellulolytic activity under a wide range of pH, temperature, and ionic conditions, and they are usually carried out by mixtures of cellulases. Investigation of the broad diversity of cellulolytic enzymes involved in the natural degradation of cellulose is necessary for optimizing these processes.

Abscisic acid and ethephon regulation of cellulase in the endosperm cap and radicle during lettuce seed germination.

PubMed

Chen, Bingxian; Ma, Jun; Xu, Zhenjiang; Wang, Xiaofeng

2016-10-01

The purpose of this study was to investigate the role of cellulase in endosperm cap weakening and radicle elongation during lettuce (Lactuca sativa L.) seed germination. The application of abscisic acid (ABA) or ethephon inhibits or promotes germination, respectively, by affecting endosperm cap weakening and radicle elongation. Cellulase activities, and related protein and transcript abundances of two lettuce cellulase genes, LsCEL1 and LsCEL2, increase in the endosperm cap and radicle prior to radicle protrusion following imbibition in water. ABA or ethephon reduce or elevate, respectively, cellulase activity, and related protein and transcript abundances in the endosperm cap. Taken together, these observations suggest that cellulase plays a role in endosperm cap weakening and radicle elongation during lettuce seed germination, and that the regulation of cellulase in the endosperm cap by ABA and ethephon play a role in endosperm cap weakening. However, the influence of ABA and ethephon on radicle elongation may not be through their effects on cellulase. © 2016 Institute of Botany, Chinese Academy of Sciences.

Using temperature-responsive zwitterionic surfactant to enhance the enzymatic hydrolysis of lignocelluloses and recover cellulase by cooling.

PubMed

Cai, Cheng; Pang, Yuxia; Zhan, Xuejuan; Zeng, Meijun; Lou, Hongming; Qian, Yong; Yang, Dongjie; Qiu, Xueqing

2017-11-01

Some zwitterionic surfactants exhibit upper critical solution temperature (UCST) in aqueous solutions. For the zwitterionic surfactant solution mixed with cellulase, when its temperature is below UCST, the cellulase can be recovered by coprecipitation with zwitterionic surfactant. In this work, 3-(Hexadecyldimethylammonio) propanesulfonate (SB3-16) was selected to enhance the enzymatic hydrolysis of lignocelluloses and recover the cellulase. After adding 2mmol/L of SB3-16, the enzymatic digestibility of eucalyptus pretreated by dilute acid (Eu-DA) and by sulfite (Eu-SPORL) increased from 27.9% and 35.1% to 72.6% and 89.7%, respectively. The results showed that SB3-16 could reduce the non-productive adsorption of cellulase on hydrophobic interface, while it did not significantly inhibit the activity of cellulase. For the solution contained 1wt% SB3-16 and 200mg protein/L CTec2 cellulase, 55.2% of protein could be recovered by cooling. The filter paper activity of the recovered cellulase was 1.93FPU/mg protein, which was 95.8% of its initial activity. Copyright © 2017. Published by Elsevier Ltd.

48 CFR 237.7100 - Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING Laundry and Dry Cleaning Services 237.7100 Scope. This subpart— (a) Applies to contracts for laundry and dry cleaning services within the United...

Application of Statistical Design for the Production of Cellulase by Trichoderma reesei Using Mango Peel.

PubMed

Saravanan, P; Muthuvelayudham, R; Viruthagiri, T

2012-01-01

Optimization of the culture medium for cellulase production using Trichoderma reesei was carried out. The optimization of cellulase production using mango peel as substrate was performed with statistical methodology based on experimental designs. The screening of nine nutrients for their influence on cellulase production is achieved using Plackett-Burman design. Avicel, soybean cake flour, KH(2)PO(4), and CoCl(2)·6H(2)O were selected based on their positive influence on cellulase production. The composition of the selected components was optimized using Response Surface Methodology (RSM). The optimum conditions are as follows: Avicel: 25.30 g/L, Soybean cake flour: 23.53 g/L, KH(2)PO(4): 4.90 g/L, and CoCl(2)·6H(2)O: 0.95 g/L. These conditions are validated experimentally which revealed an enhanced Cellulase activity of 7.8 IU/mL.

Electrotransformation and expression of cellulase genes in wild-type Lactobacillus reuteri.

PubMed

Li, Wang; Yang, Ming-Ming; Zhang, Guang-Qin; He, Wan-Ling; Li, Yuan-Xiao; Chen, Yu-Lin

2012-01-01

Two cellulase genes, Cel15 and Cel73, were amplified from Bacillus subtilis genome DNA in a previous study. Two integrative vectors, pLEM4153 and pLEM4154, containing the genes Cel15 and Cel73, respectively, were constructed and successfully electroporated into the wild-type Lactobacillus reuteri which was isolated from chick guts through an optimized procedure. Two recombinant L. reuteri were selected from a Man, Rogosa, and Sharp (MRS) plate with 10 µg/ml erythromycin, and named L. reuteri XNY-Cel15 and L. reuteri XNY-Cel73, respectively. To verify the transcription and expression of the two cellulase genes in the recombinant L. reuteri strains, the mRNA relative quantity (RQ) and the cellulase activity were determined. The mRNA RQ of Cel15 in L. reuteri XNY-Cel15 is 1,8849.5, and that of Cel73 in L. reuteri XNY-Cel73 is 1,388, and the cellulase activity of the modified MRS broth cultured with L. reuteri XNY-Cel15 was 0.158 U/ml, whereas that with L. reuteri XNY-Cel73 was 0.15 U/ml. Copyright © 2012 S. Karger AG, Basel.

Improving cellulase productivity of Penicillium oxalicum RE-10 by repeated fed-batch fermentation strategy.

PubMed

Han, Xiaolong; Song, Wenxia; Liu, Guodong; Li, Zhonghai; Yang, Piao; Qu, Yinbo

2017-03-01

Medium optimization and repeated fed-batch fermentation were performed to improve the cellulase productivity by P. oxalicum RE-10 in submerged fermentation. First, Plackett-Burman design (PBD) and central composite design (CCD) were used to optimize the medium for cellulase production. PBD demonstrated wheat bran and NaNO 3 had significant influences on cellulase production. The CCD results showed the maximum filter paper activity (FPA) production of 8.61U/mL could be achieved in Erlenmeyer flasks. The maximal FPA reached 12.69U/mL by submerged batch fermentation in a 7.5-L stirred tank, 1.76-fold higher than that on the original medium. Then, the repeated fed-batch fermentation strategy was performed successfully for increasing the cellulase productivity from 105.75U/L/h in batch fermentation to 158.38U/L/h. The cellulase activity and the glucan conversion of delignined corn cob residue hydrolysis had no significant difference between the enzymes sampled from different cycles of the repeated fed-batch fermentation and that from batch culture. Copyright © 2016 Elsevier Ltd. All rights reserved.

Synthetic Gene Network with Positive Feedback Loop Amplifies Cellulase Gene Expression in Neurospora crassa.

PubMed

Matsu-Ura, Toru; Dovzhenok, Andrey A; Coradetti, Samuel T; Subramanian, Krithika R; Meyer, Daniel R; Kwon, Jaesang J; Kim, Caleb; Salomonis, Nathan; Glass, N Louise; Lim, Sookkyung; Hong, Christian I

2018-05-18

Second-generation or lignocellulosic biofuels are a tangible source of renewable energy, which is critical to combat climate change by reducing the carbon footprint. Filamentous fungi secrete cellulose-degrading enzymes called cellulases, which are used for production of lignocellulosic biofuels. However, inefficient production of cellulases is a major obstacle for industrial-scale production of second-generation biofuels. We used computational simulations to design and implement synthetic positive feedback loops to increase gene expression of a key transcription factor, CLR-2, that activates a large number of cellulases in a filamentous fungus, Neurospora crassa. Overexpression of CLR-2 reveals previously unappreciated roles of CLR-2 in lignocellulosic gene network, which enabled simultaneous induction of approximately 50% of 78 lignocellulosic degradation-related genes in our engineered Neurospora strains. This engineering results in dramatically increased cellulase activity due to cooperative orchestration of multiple enzymes involved in the cellulose degradation pathway. Our work provides a proof of principle in utilizing mathematical modeling and synthetic biology to improve the efficiency of cellulase synthesis for second-generation biofuel production.

The C. elegans embryonic fate specification factor EGL-18 (GATA) is reutilized downstream of Wnt signaling to maintain a population of larval progenitor cells.

PubMed

Gorrepati, Lakshmi; Eisenmann, David M

2015-01-01

In metazoans, stem cells in developing and adult tissues can divide asymmetrically to give rise to a daughter that differentiates and a daughter that retains the progenitor fate. Although the short-lived nematode C. elegans does not possess adult somatic stem cells, the lateral hypodermal seam cells behave in a similar manner: they divide once per larval stage to generate an anterior daughter that adopts a non-dividing differentiated fate and a posterior daughter that retains the seam fate and the ability to divide further. Wnt signaling pathway is known to regulate the asymmetry of these divisions and maintain the progenitor cell fate in one daughter, but how activation of the Wnt pathway accomplished this was unknown. We describe here our recent work that identified the GATA transcription factor EGL-18 as a downstream target of Wnt signaling necessary for maintenance of a progenitor population of larval seam cells. EGL-18 was previously shown to act in the initial specification of the seam cells in the embryo. Thus the acquisition of a Wnt-responsive cis-regulatory module allows an embryonic fate specification factor to be reutilized later in life downstream of a different regulator (Wnt signaling) to maintain a progenitor cell population. These results support the use of seam cell development in C. elegans as a simple model system for studying stem and progenitor cell biology.

Silage fermentation and ruminal degradation of stylo prepared with lactic acid bacteria and cellulase.

PubMed

Li, Mao; Zhou, Hanlin; Zi, Xuejuan; Cai, Yimin

2017-10-01

In order to improve the silage fermentation of stylo (Stylosanthes guianensis) in tropical areas, stylo silages were prepared with commercial additives Lactobacillus plantarum Chikuso-1 (CH1), L. rhamnasus Snow Lact L (SN), Acremonium cellulase (CE) and their combination as SN+CE or CH1 + CE, and the fermentation quality, chemical composition and ruminal degradation of these silages were studied. Stylo silages treated with lactic acid bacteria (LAB) or cellulase, the pH value and NH 3 -N ⁄ total-N were significantly (P < 0.05) decreased while the ruminal degradability of dry matter (DM), crude protein (CP), neutral detergent fiber (aNDFom) and acid detergent fiber (ADFom) were significantly (P < 0.05) increased compared to control. Compared to LAB or cellulase-treated silages, the DM, CP contents and relative feed value (RFV), and the ruminal degradability in LAB plus cellulase-treated silages were significantly (P < 0.05) higher, but the aNDFom content was significantly (P < 0.05) lower. CH1 + CE treatment was more effective in silage fermentation and ruminal degradation than SN+CE treatment. The results confirmed that LAB or LAB plus cellulase treatment could improve the fermentation quality, chemical composition and ruminal degradation of stylo silage. Moreover, the combined treatment with LAB and cellulase may have beneficial synergistic effects on ruminal degradation. © 2017 Japanese Society of Animal Science.

Biokinetics of /sup 237/Np in mussels and shrimp

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guary, J.C.; Fowler, S.W.

1977-01-01

Neptunium-237 kinetics were studied in marine shrimp and mussels using a thick source alpha counting technique. Bioaccumulation of /sup 237/Np from water was relatively slow in both species, reaching whole body concentration factors of only 15 to 20 after three months. Surface adsorption was implicated in the initial uptake. Both uptake and loss of the radioisotope were not significantly affected by temperature; this may be a reflection of the physical nature of the uptake. By virtue of the large amounts of accumulated /sup 237/Np associated with the exoskeleton of shrimp, molting will play an important role in the biogeochemical cyclingmore » of this transuranic in the marine environment. Rapid growth of organisms like mussels acts to reduce the /sup 237/Np concentration in tissues during a period of decontamination.« less

33 CFR 110.237 - Pacific Ocean at Waimea, Hawaii, Naval Anchorage.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Pacific Ocean at Waimea, Hawaii, Naval Anchorage. 110.237 Section 110.237 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.237 Pacific Ocean at Waimea...

33 CFR 110.237 - Pacific Ocean at Waimea, Hawaii, Naval Anchorage.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Pacific Ocean at Waimea, Hawaii, Naval Anchorage. 110.237 Section 110.237 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.237 Pacific Ocean at Waimea...

33 CFR 110.237 - Pacific Ocean at Waimea, Hawaii, Naval Anchorage.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Pacific Ocean at Waimea, Hawaii, Naval Anchorage. 110.237 Section 110.237 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.237 Pacific Ocean at Waimea...

A Newly Isolated Penicillium oxalicum 16 Cellulase with High Efficient Synergism and High Tolerance of Monosaccharide.

PubMed

Zhao, Xi-Hua; Wang, Wei; Tong, Bin; Zhang, Su-Ping; Wei, Dong-Zhi

2016-01-01

Compared to Trichoderma reesei RUT-C30 cellulase (Trcel), Penicillium oxalicum 16 cellulase (P16cel) from the fermentation supernatant produced a 2-fold higher glucose yield when degrading microcrystalline cellulose (MCC), possessed a 10-fold higher β-glucosidase (BGL) activity, but obtained somewhat lower other cellulase component activities. The optimal temperature and pH of β-1,4-endoglucanase, cellobiohydrolase, and filter paperase from P16cel were 50-60 °C and 4-5, respectively, but those of BGL reached 70 °C and 5. The cellulase cocktail of P16cel and Trcel had a high synergism when solubilizing MCC and generated 1.7-fold and 6.2-fold higher glucose yields than P16cel and Trcel at the same filter paperase loading, respectively. Additional low concentration of fructose enhanced the glucose yield during enzymatic hydrolysis of MCC; however, additional high concentration of monosaccharide (especially glucose) reduced cellulase activities and gave a stronger monosaccharide inhibition on Trcel. These results indicate that P16cel is a more excellent cellulase than Trcel.

Application of Statistical Design for the Production of Cellulase by Trichoderma reesei Using Mango Peel

PubMed Central

Saravanan, P.; Muthuvelayudham, R.; Viruthagiri, T.

2012-01-01

Optimization of the culture medium for cellulase production using Trichoderma reesei was carried out. The optimization of cellulase production using mango peel as substrate was performed with statistical methodology based on experimental designs. The screening of nine nutrients for their influence on cellulase production is achieved using Plackett-Burman design. Avicel, soybean cake flour, KH2PO4, and CoCl2 ·6H2O were selected based on their positive influence on cellulase production. The composition of the selected components was optimized using Response Surface Methodology (RSM). The optimum conditions are as follows: Avicel: 25.30 g/L, Soybean cake flour: 23.53 g/L, KH2PO4: 4.90 g/L, and CoCl2 ·6H2O: 0.95 g/L. These conditions are validated experimentally which revealed an enhanced Cellulase activity of 7.8 IU/mL. PMID:23304453

48 CFR 237.7301 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... good standing in a curriculum designed to lead to the granting of a recognized degree, during the term... Development Laboratories 237.7301 Definitions. As used in this subpart— (a) Institution of higher learning...

Central carbon metabolism influences cellulase production in Bacillus licheniformis.

PubMed

Wang, J; Liu, S; Li, Y; Wang, H; Xiao, S; Li, C; Liu, B

2018-01-01

Bacillus licheniformis that can produce cellulase including endo glucanase and glucosidase is an important industrial microbe for cellulose degradation. The purpose of this research was to assess the effect of endo glucanase gene bglC and glucosidase gene bglH on the central metabolic flux in B. licheniformis. bglC and bglH were knocked out using homologous recombination method, respectively, and the corresponding knockout strains were obtained for 13 C metabolic flux analysis. A significant change was observed in metabolic fluxes after 13 C metabolic flux ratio analysis. In both of the knockout strains, the increased fluxes of the pentose phosphate pathway and malic enzyme reaction enabled an elevated supply of NADPH which provided enough reducing power for the in vivo synthesis reactions. The fluxes through tricarboxylic acid cycle and anaplerotic reactions increased fast in the two knockout strains, which meant more energy generated. The changed fluxes in central carbon metabolism provided a holistic view of the physiological status in B. licheniformis and possible targets for further strain engineering. Cellulase is very important in the field of agriculture and bioenergy because of its degrading effect on cellulosic biomass. This study presented the effect of central carbon metabolism on cellulase production in Bacillus licheniformis. The study also provided a holistic view of the physiological status in B. licheniformis. The shifted metabolism provided a quantitative evaluation of the biosynthesis of cellulase and a priority ranked target list for further strain engineering. © 2017 The Society for Applied Microbiology.

Character of cellulase activity in the guts of flagellate-free termites with different feeding habits.

PubMed

Li, Zhi-Qiang; Liu, Bing-Rong; Zeng, Wen-Hui; Xiao, Wei-Liang; Li, Qiu-Jian; Zhong, Jun-Hong

2013-01-01

Cellulose digestion in termites (Isoptera) is highly important for ecological reasons and applications in biofuel conversion. The speciose Termitidae family has lost flagellates in the hindgut and developed diverse feeding habits. To address the response of cellulase activity to the differentiation of feeding habits, a comparative study of the activity and distribution of composite cellulases, endo-β-1,4-glucanase, and β-glucosidase was performed in seven common flagellate-free termites with three feeding habits: the humus-feeding termites Sinocapritermes mushae (Oshima et Maki), Malaysiocapritermes zhangfengensis Zhu, Yang et Huang and Pericapritermes jiangtsekiangensis (Kemner); the fungus-growing termites Macrotermes barneyi Light and Odontotermes formosanus (Shiraki); and the wood-feeding termites Nasutitermes parvonasutus (Shiraki) and Havilanditermes orthonasus (Tsai et Chen). The results showed that in diverse feeding groups, the wood-feeding group had the highest total composite cellulase and endo-β-1,4-glucanase activities, while the fungus-growing group had the highest β-glucosidase activity. In terms of the distribution of cellulase activity in the alimentary canals, the cellulase activities in wood-feeding termites were concentrated in the midgut, but there was no significant difference between all gut segments in humus-feeding termites. As for the fungus-growing termites, the main site of composite cellulase activity was in the midgut. The endo-β-1,4-glucanase activity was restricted to the midgut, but the primary site of β-glucosidase activity was in the foregut and the midgut (Mac. barneyi). The functions of the gut segments apparently differentiated between feeding groups. The results suggest that the differentiation of feeding habits in flagellate-free termites was characterized by the distribution of cellulases in the gut rather than by variations in cellulase activity.

Character of Cellulase Activity in the Guts of Flagellate-Free Termites with Different Feeding Habits

PubMed Central

Li, Zhi-Qiang; Liu, Bing-Rong; Zeng, Wen-Hui; Xiao, Wei-Liang; Li, Qiu-Jian; Zhong, Jun-Hong

2013-01-01

Cellulose digestion in termites (Isoptera) is highly important for ecological reasons and applications in biofuel conversion. The speciose Termitidae family has lost flagellates in the hindgut and developed diverse feeding habits. To address the response of cellulase activity to the differentiation of feeding habits, a comparative study of the activity and distribution of composite cellulases, endo-β-1, 4-glucanase, and β-glucosidase was performed in seven common flagellate-free termites with three feeding habits: the humus-feeding termites Sinocapritermes mushae (Oshima et Maki), Malaysiocapritermes zhangfengensis Zhu, Yang et Huang and Pericapritermes jiangtsekiangensis (Kemner); the fungus-growing termites Macrotermes barneyi Light and Odontotermes formosanus (Shiraki); and the wood-feeding termites Nasutitermes parvonasutus (Shiraki) and Havilanditermes orthonasus (Tsai et Chen). The results showed that in diverse feeding groups, the wood-feeding group had the highest total composite cellulase and endo-β-1, 4-glucanase activities, while the fungus-growing group had the highest β-glucosidase activity. In terms of the distribution of cellulase activity in the alimentary canals, the cellulase activities in wood-feeding termites were concentrated in the midgut, but there was no significant difference between all gut segments in humus-feeding termites. As for the fungus-growing termites, the main site of composite cellulase activity was in the midgut. The endo-β-1, 4-glucanase activity was restricted to the midgut, but the primary site of β-glucosidase activity was in the foregut and the midgut (Mac. barneyi). The functions of the gut segments apparently differentiated between feeding groups. The results suggest that the differentiation of feeding habits in flagellate-free termites was characterized by the distribution of cellulases in the gut rather than by variations in cellulase activity. PMID:23895662

Characterization of thermostable cellulase produced by Bacillus strains isolated from solid waste of carrageenan

NASA Astrophysics Data System (ADS)

Listyaningrum, N. P.; Sutrisno, A.; Wardani, A. K.

2018-03-01

Cellulase-producing bacteria was isolated from solid waste of carrageenan and identified as Bacillus licheniformis C55 by 16S rRNA sequencing. The optimum condition for cellulase production was obtained at pH and temperature of 8.0 and 50°C, respectively in a medium containing glucose as carbon source and 1.0% carboxymethyl cellulose (CMC) to stimulate the cellulase production. Most remarkably, the enzyme retained its relative activity over 50% after incubation at 50°C for 90 minutes. Substrate specificity suggested that the enzyme is an endoglucanase. The molecular mass of Bacillus licheniformis C55 crude cellulase was found about 18 kDa by SDS-PAGE analysis. This thermostable enzyme would facilitate development of more efficient and cost-effective forms of the process to convert lignocellulosic biomass into high-value products.

Study of cellulase enzymes self-assembly in aqueous-acetonitrile solvent: Viscosity measurements

NASA Astrophysics Data System (ADS)

Ghaouar, N.; Aschi, A.; Belbahri, L.; Trabelsi, S.; Gharbi, A.

2009-11-01

The present study extends the viscosity measurements performed by Ghaouar et al. [Physica B, submitted for publication.] to study the conformational change of the cellulase enzymes in aqueous-acetonitrile mixture. We aim to investigate: (i) the denaturation process by measuring the specific viscosity for temperatures varying between 25 and 65 °C and acetonitrile concentrations between 0% and 50%, (ii) the enzyme-enzyme interaction by calculating the Huggins coefficient and (iii) the enzyme sizes by following the hydrodynamic radius for various temperatures. The precipitation of cellulases versus acetonitrile concentration is also considered. We show from all physical quantities measured in this work that the precipitation and the denaturation processes of cellulase enzymes exist together.

Strain improvement of Trichoderma viride for increased cellulase production by irradiation of electron and (12)C(6+)-ion beams.

PubMed

Li, Zhaozhou; Chen, Xiujin; Li, Zhili; Li, Daomin; Wang, Yao; Gao, Hongli; Cao, Li; Hou, Yuze; Li, Songbiao; Liang, Jianping

2016-06-01

To improve cellulase production and activity, Trichoderma viride GSICC 62010 was subjected to mutation involving irradiation with an electron beam and subsequently with a (12)C(6+)-ion beam. Mutant CIT 626 was the most promising cellulase producer after preliminary and secondary screening. Soluble protein production and cellulase activities were increased mutifold. The optimum temperature, pH and culture time for the maximum cellulase production of the selected mutant were 35 °C, pH 5 and 6 days. The highest cellulase production was obtained using wheat bran. The prepared cellulases from T. viride CIT 626 had twice the hydrolytic performance with sawdust (83 %) than that from the parent strain (42.5 %). Furthermore, molecular studies demonstrated that there were some key mutation sites suggesting that some amino acid changes in the protein caused by base mutations had led to the enhanced cellulase production and activity. Mutagenesis with electron and (12)C(6+)-ion beams could be developed as an effective tool for improvement of cellulase producing strains.

Microplate-based filter paper assay to measure total cellulase activity.

PubMed

Xiao, Zhizhuang; Storms, Reginald; Tsang, Adrian

2004-12-30

The standard filter paper assay (FPA) published by the International Union of Pure and Applied Chemistry (IUPAC) is widely used to determine total cellulase activity. However, the IUPAC method is not suitable for the parallel analyses of large sample numbers. We describe here a microplate-based method for assaying large sample numbers. To achieve this, we reduced the enzymatic reaction volume to 60 microl from the 1.5 ml used in the IUPAC method. The modified 60-microl format FPA can be carried out in 96-well assay plates. Statistical analyses showed that the cellulase activities of commercial cellulases from Trichoderma reesei and Aspergillus species determined with our 60-microl format FPA were not significantly different from the activities measured with the standard FPA. Our results also indicate that the 60-microl format FPA is quantitative and highly reproducible. Moreover, the addition of excess beta-glucosidase increased the sensitivity of the assay by up to 60%. 2004 Wiley Periodicals, Inc.

Improvement of halophilic cellulase production from locally isolated fungal strain.

PubMed

Gunny, Ahmad Anas Nagoor; Arbain, Dachyar; Jamal, Parveen; Gumba, Rizo Edwin

2015-07-01

Halophilic cellulases from the newly isolated fungus, Aspergillus terreus UniMAP AA-6 were found to be useful for in situ saccharification of ionic liquids treated lignocelluloses. Efforts have been taken to improve the enzyme production through statistical optimization approach namely Plackett-Burman design and the Face Centered Central Composite Design (FCCCD). Plackett-Burman experimental design was used to screen the medium components and process conditions. It was found that carboxymethylcellulose (CMC), FeSO4·7H2O, NaCl, MgSO4·7H2O, peptone, agitation speed and inoculum size significantly influence the production of halophilic cellulase. On the other hand, KH2PO4, KOH, yeast extract and temperature had a negative effect on enzyme production. Further optimization through FCCCD revealed that the optimization approach improved halophilic cellulase production from 0.029 U/ml to 0.0625 U/ml, which was approximately 2.2-times greater than before optimization.

Improvement of halophilic cellulase production from locally isolated fungal strain

PubMed Central

Gunny, Ahmad Anas Nagoor; Arbain, Dachyar; Jamal, Parveen; Gumba, Rizo Edwin

2014-01-01

Halophilic cellulases from the newly isolated fungus, Aspergillus terreus UniMAP AA-6 were found to be useful for in situ saccharification of ionic liquids treated lignocelluloses. Efforts have been taken to improve the enzyme production through statistical optimization approach namely Plackett–Burman design and the Face Centered Central Composite Design (FCCCD). Plackett–Burman experimental design was used to screen the medium components and process conditions. It was found that carboxymethylcellulose (CMC), FeSO4·7H2O, NaCl, MgSO4·7H2O, peptone, agitation speed and inoculum size significantly influence the production of halophilic cellulase. On the other hand, KH2PO4, KOH, yeast extract and temperature had a negative effect on enzyme production. Further optimization through FCCCD revealed that the optimization approach improved halophilic cellulase production from 0.029 U/ml to 0.0625 U/ml, which was approximately 2.2-times greater than before optimization. PMID:26150755

The effect of leachate recirculation with enzyme cellulase addition on waste stability in landfill bioreactor

NASA Astrophysics Data System (ADS)

Saffira, N.; Kristanto, G. A.

2018-01-01

Landfill bioreactor with leachate recirculation is known to enhance waste stabilization. However, the composition of waste in Indonesia is comprised by organic waste which is lignocellulosic materials that considered take a long time to degrade under anaerobic condition. To accelerate the degradation process, enzyme addition is ought to do. Cellulase is an enzyme that can catalyse cellulose and other polysaccharide decomposition processes. Therefore, operation of waste degradation using leachate recirculation with a cellulase addition to enhance waste stabilization was investigated using anaerobic bioreactor landfill. The experiment was performed on 2 conditions; leachate recirculation with cellulase addition and recirculation only as a control. The addition of cellulase is reported to be significant in decreasing organic content, represented by volatile solid parameter. The volatile solid reduction in the cellulase augmented reactor and control reactor was 17.86% and 7.90%, respectively. Cellulase addition also resulted in the highest cellulose reduction. Settlement of the landfill in a bioreactor with enzyme addition (32.67%) was reported to be higher than the control (19.33%). Stabilization of landfill review by the decreasing rate constant of the cellulose and lignin ratio parameter was more rapidly achieved by the enzyme addition (0.014 day-1) compared to control (0.002 day-1).

48 CFR 52.237-11 - Accepting and Dispensing of $1 Coin.

Code of Federal Regulations, 2011 CFR

2011-10-01

... of $1 Coin. 52.237-11 Section 52.237-11 Federal Acquisition Regulations System FEDERAL ACQUISITION... Clauses 52.237-11 Accepting and Dispensing of $1 Coin. As prescribed in 37.116-2, insert the following clause: Accepting and Dispensing of $1 Coin (SEP 2008) (a) This clause applies to service contracts that...

48 CFR 52.237-11 - Accepting and Dispensing of $1 Coin.

Code of Federal Regulations, 2010 CFR

2010-10-01

... of $1 Coin. 52.237-11 Section 52.237-11 Federal Acquisition Regulations System FEDERAL ACQUISITION... Clauses 52.237-11 Accepting and Dispensing of $1 Coin. As prescribed in 37.116-2, insert the following clause: Accepting and Dispensing of $1 Coin (SEP 2008) (a) This clause applies to service contracts that...

48 CFR 2452.237-73 - Conduct of Work and Technical Guidance.

Code of Federal Regulations, 2010 CFR

2010-10-01

... conditions of the contract. (c) The GTR will issue technical guidance in writing or, if issued orally, he/she... Technical Guidance. 2452.237-73 Section 2452.237-73 Federal Acquisition Regulations System DEPARTMENT OF... Provisions and Clauses 2452.237-73 Conduct of Work and Technical Guidance. As prescribed in 2437.110(d...

Thermostable, haloalkaline cellulase from Bacillus halodurans CAS 1 by conversion of lignocellulosic wastes.

PubMed

Annamalai, Neelamegam; Rajeswari, Mayavan Veeramuthu; Elayaraja, Sivaramasamy; Balasubramanian, Thangavel

2013-04-15

An extracellular thermostable, haloalkaline cellulase by bioconversion of lignocellulosic wastes from Bacillus halodurans CAS 1 was purified to homogeneity with recovery of 12.54% and purity fold 7.96 with the molecular weight of 44 kDa. The optimum temperature, pH and NaCl for enzyme activity was determined as 60°C, 9.0 and 30% and it retained 80% of activity even at 80°C, 12 and 35% respectively. The activity was greatly inhibited by EDTA, indicating that it was a metalloenzyme and significant inhibition by PMSF revealed that serine residue was essential for catalytic activity. The purified cellulase hydrolyzed CMC, cellobiose and xylan, but not avicel, cellulose and PNPG. Furthermore, the cellulase was highly stable in the presence of detergents and organic solvents such as acetone, n-hexane and acetonitrile. Thus, the purified cellulase from B. halodurans utilizing lignocellulosic biomass could be greatly useful to develop industrial processes. Published by Elsevier Ltd.

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger

DOE PAGES

Amaike Campen, Saori; Lynn, Jed; Sibert, Stephanie J.; ...

2017-12-27

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme productionmore » host before they could be considered a viable alternative to current commercial cellulases. Aspergillus Niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. Niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. Niger and Escherichia coli. Finally, this comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. Niger is equivalent, suggesting that A. Niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.« less

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amaike Campen, Saori; Lynn, Jed; Sibert, Stephanie J.

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme productionmore » host before they could be considered a viable alternative to current commercial cellulases. Aspergillus Niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. Niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. Niger and Escherichia coli. Finally, this comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. Niger is equivalent, suggesting that A. Niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.« less

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger

PubMed Central

Lynn, Jed; Sibert, Stephanie J.; Srikrishnan, Sneha; Phatale, Pallavi; Feldman, Taya; Guenther, Joel M.; Hiras, Jennifer; Tran, Yvette Thuy An; Singer, Steven W.; Adams, Paul D.; Sale, Kenneth L.; Simmons, Blake A.; Baker, Scott E.; Magnuson, Jon K.; Gladden, John M.

2017-01-01

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme production host before they could be considered a viable alternative to current commercial cellulases. Aspergillus niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. niger and Escherichia coli. This comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. niger is equivalent, suggesting that A. niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry. PMID:29281693

Expression of naturally ionic liquid-tolerant thermophilic cellulases in Aspergillus niger.

PubMed

Amaike Campen, Saori; Lynn, Jed; Sibert, Stephanie J; Srikrishnan, Sneha; Phatale, Pallavi; Feldman, Taya; Guenther, Joel M; Hiras, Jennifer; Tran, Yvette Thuy An; Singer, Steven W; Adams, Paul D; Sale, Kenneth L; Simmons, Blake A; Baker, Scott E; Magnuson, Jon K; Gladden, John M

2017-01-01

Efficient deconstruction of plant biomass is a major barrier to the development of viable lignocellulosic biofuels. Pretreatment with ionic liquids reduces lignocellulose recalcitrance to enzymatic hydrolysis, increasing yields of sugars for conversion into biofuels. However, commercial cellulases are not compatible with many ionic liquids, necessitating extensive water washing of pretreated biomass prior to hydrolysis. To circumvent this issue, previous research has demonstrated that several thermophilic bacterial cellulases can efficiently deconstruct lignocellulose in the presence of the ionic liquid, 1-ethyl-3-methylimadizolium acetate. As promising as these enzymes are, they would need to be produced at high titer in an industrial enzyme production host before they could be considered a viable alternative to current commercial cellulases. Aspergillus niger has been used to produce high titers of secreted enzymes in industry and therefore, we assessed the potential of this organism to be used as an expression host for these ionic liquid-tolerant cellulases. We demonstrated that 29 of these cellulases were expressed at detectable levels in a wild-type strain of A. niger, indicating a basic level of compatibility and potential to be produced at high levels in a host engineered to produce high titers of enzymes. We then profiled one of these enzymes in detail, the β-glucosidase A5IL97, and compared versions expressed in both A. niger and Escherichia coli. This comparison revealed the enzymatic activity of A5IL97 purified from E. coli and A. niger is equivalent, suggesting that A. niger could be an excellent enzyme production host for enzymes originally characterized in E. coli, facilitating the transition from the laboratory to industry.

Characterization and pulp refining activity of a Paenibacillus campinasensis cellulase expressed in Escherichia coli.

PubMed

Ko, Chun-Han; Tsai, Chung-Hung; Lin, Po-Heng; Chang, Ko-Cheng; Tu, Jenn; Wang, Ya-Nang; Yang, Chien-Ying

2010-10-01

The Cel-BL11 gene from Paenibacillus campinasensis BL11 was cloned and expressed in Escherichia coli as a His-tag fusion protein. Zymographic analysis of the recombinant protein revealed cellulase activity corresponding to a protein with a 38-kDa molecular weight. The optimum temperature and pH for purified cellulase were 60 °C and pH 7.0, respectively. The enzyme retained more than 80% activity after 8h at 60 °C at pH 6 and 7. The cellulase has a Km of 11.25 mg/ml and a Vmax of 1250 μmol/min/mg with carboxylmethyl cellulose (CMC). Then enzyme was active on Avicel, swollen Avicel, CMC, barley β-glucan, laminarin in the presence of 100 mM acetate buffer. It was inhibited by Hg²⁺, Cu²⁺ and Zn²⁺. Significant kraft pulp refining energy saving, 10%, was exhibited by the pretreatment of this cellulase applied at 2 IU per gram of oven-dried pulp. Broad pH and temperature stability render this cellulase a convenient applicability toward current mainstream biomass conversion and other industrial processes. Copyright © 2010 Elsevier Ltd. All rights reserved.

Analysis of cellulase and polyphenol oxidase production by southern pine beetle associated fungi

Treesearch

Abduvali Valiev; Zumrut B. Ogel; Dier D. Klepzig

2009-01-01

In this study, the production of extracellular enzymes by fungi associated with southern pine beetle was investigated for the first time. Cellulase and polyphenol oxidase production were analyzed for three beetle associated fungi. Only the mutualistic symbiont Entomocorticium sp. A was found to produce cellulases and polyphenol oxidase....

Roles of Protein Kinase A and Adenylate Cyclase in Light-Modulated Cellulase Regulation in Trichoderma reesei

PubMed Central

Schuster, André; Tisch, Doris; Seidl-Seiboth, Verena; Kubicek, Christian P.

2012-01-01

The cyclic AMP (cAMP) pathway represents a central signaling cascade with crucial functions in all organisms. Previous studies of Trichoderma reesei (anamorph of Hypocrea jecorina) suggested a function of cAMP signaling in regulation of cellulase gene expression. We were therefore interested in how the crucial components of this pathway, adenylate cyclase (ACY1) and cAMP-dependent protein kinase A (PKA), would affect cellulase gene expression. We found that both ACY1 and PKA catalytic subunit 1 (PKAC1) are involved in regulation of vegetative growth but are not essential for sexual development. Interestingly, our results showed considerably increased transcript abundance of cellulase genes in darkness compared to light (light responsiveness) upon growth on lactose. This effect is strongly enhanced in mutant strains lacking PKAC1 or ACY1. Comparison to the wild type showed that ACY1 has a consistently positive effect on cellulase gene expression in light and darkness, while PKAC1 influences transcript levels of cellulase genes positively in light but negatively in darkness. A function of PKAC1 in light-modulated cellulase gene regulation is also reflected by altered complex formation within the cel6a/cbh2 promoter in light and darkness and in the absence of pkac1. Analysis of transcript levels of cellulase regulator genes indicates that the regulatory output of the cAMP pathway may be established via adjustment of XYR1 abundance. Consequently, both adenylate cyclase and protein kinase A are involved in light-modulated cellulase gene expression in T. reesei and have a dampening effect on the light responsiveness of this process. PMID:22286997

49 CFR 237.33 - Content of bridge management programs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Content of bridge management programs. 237.33... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.33 Content of bridge management programs. Each bridge management program adopted in compliance with this part...

49 CFR 237.31 - Adoption of bridge management programs.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Adoption of bridge management programs. 237.31... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.31 Adoption of bridge management programs. Each track owner shall adopt a bridge safety management program to...

49 CFR 237.111 - Review of bridge inspection reports.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Review of bridge inspection reports. 237.111... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge inspection reports. Bridge inspection reports shall be reviewed by railroad bridge supervisors and railroad...

48 CFR 1552.237-70 - Contract publication review procedures.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 6 2010-10-01 2010-10-01 true Contract publication review procedures. 1552.237-70 Section 1552.237-70 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION... Project Officer, at least 30 days prior to publication, a copy of any paper, article, or other...

49 CFR 237.111 - Review of bridge inspection reports.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Review of bridge inspection reports. 237.111... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Bridge Inspection § 237.111 Review of bridge inspection reports. Bridge inspection reports shall be reviewed by railroad bridge supervisors and railroad...

49 CFR 237.31 - Adoption of bridge management programs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Adoption of bridge management programs. 237.31... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.31 Adoption of bridge management programs. Each track owner shall adopt a bridge safety management program to...

49 CFR 237.33 - Content of bridge management programs.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Content of bridge management programs. 237.33... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Railroad Bridge Safety Assurance § 237.33 Content of bridge management programs. Each bridge management program adopted in compliance with this part...

Immobilization of cellulase on a silica gel substrate modified using a 3-APTES self-assembled monolayer

DOE PAGES

Zhang, Dezhi; Hegab, Hisham E.; Lvov, Yuri; ...

2016-01-20

Cellulase was immobilized onto silica gel surfaces pretreated with (3-aminopropyl) triethoxy-silane (3-APTES), and glutaraldehyde (GA) was used as a cross-linker. A carboxymethyl cellulose sodium salt (CMC) solution was used for activity experiments. Protein assay was performed to determine the mass immobilized and compare with free enzyme. Cellulase was successfully demonstrated to be immobilized on the modified silica gel surface, and no detectable amount of enzyme was stripped off during the hydrolysis of the CMC solution. The specific activity of the immobilized cellulase is 7 ± 2 % compared to the similar amount of free cellulase. Significant activity over multiple reusesmore » was observed. The seventh batch achieved 82 % activity of the initial batch, and the fifteenth batch retained 31 %. Lastly, it was observed that the immobilized cellulase retained 48 % of its initial activity after 4 days, and 22 % even after 14 days.« less

Cellulase enzyme: Homology modeling, binding site identification and molecular docking

NASA Astrophysics Data System (ADS)

Selvam, K.; Senbagam, D.; Selvankumar, T.; Sudhakar, C.; Kamala-Kannan, S.; Senthilkumar, B.; Govarthanan, M.

2017-12-01

Cellulase is an enzyme that degrades the linear polysaccharide like cellulose into glucose by breaking the β-1,4- glycosidic bonds. These enzymes are the third largest enzymes with a great potential towards the ethanol production and play a vital role in degrading the biomass. The production of ethanol depends upon the ability of the cellulose to utilize the wide range of substrates. In this study, the 3D structure of cellulase from Acinetobacter sp. was modeled by using Modeler 9v9 and validated by Ramachandran plot. The accuracy of the predicted 3D structure was checked using Ramachandran plot analysis showed that 81.1% in the favored region, compatibility of an atomic model (3D) with amino acid sequence (1D) for the model was observed as 78.21% and 49.395% for Verify 3D and ERRAT at SAVES server. As the binding efficacy with the substrate might suggests the choice of the substrate as carbon and nitrogen sources, the cellobiose, cellotetraose, cellotetriose and laminaribiose were employed in the docking studies. The docking of cellobiose, cellotetraose, cellotetriose and laminaribiose with cellulase exhibited the binding energy of -6.1523 kJ/mol, -7.8759 kJ/mol,-6.1590 kJ/mol and -6.7185 kJ/mol, respectively. These docking studies revealed that cellulase has the greater potential towards the cellotetraose as a substrate for the high yield of ethanol.

Intake, digestibility, and composition of orchardgrass and alfalfa silages treated with cellulase, inoculant, and formic acid fed to lambs.

PubMed

Nadeau, E M; Russell, J R; Buxton, D R

2000-11-01

The objectives of this study were to determine the effect of a cellulase (from Trichoderma longibrachiatum) alone or combined with a bacterial inoculant (Lactobacillus plantarum and Pediococcus cerevisiae) or formic acid on composition, intake, and digestibility of orchardgrass (Dactylis glomerata L.) and alfalfa (Medicago sativa L.) silages. Orchardgrass and alfalfa were harvested at the early heading stage and at the early bloom stage of maturity and wilted to approximately 22 and 32% DM, respectively. Forages were then ensiled in 100-L sealed barrels for at least 60 d before they were fed to lambs. Silage treated with cellulase had lower (P < .001) pH and lower (P < .001) acetic acid and NH3 N concentrations than untreated silage of both plant species and a higher (P = .004) lactic acid concentration than the control treatment of alfalfa silage. Fermentation characteristics of cellulase-treated silages, especially of alfalfa, were further enhanced by use of inoculant. Formic acid addition increased (P < .001), reducing sugar concentration of cellulase-treated orchardgrass and alfalfa silage by 90 and 154%, respectively, and decreased (P < .001) NH3 N concentration of cellulase-treated alfalfa silage by 19%. Averaged across plant species, cellulase, combined with inoculant or formic acid, resulted in 8 and 13% greater (P = .03) DMI, respectively, than the control silage. Extensive enzymatic cell-wall degradation during ensiling decreased (P = .003) NDF intake of cellulase-treated orchardgrass silage by 25% and decreased (P = .001) cellulose intake by 23%, when averaged across plant species. Addition of formic acid increased (P = .003) NDF intake of cellulase-treated orchardgrass silage by 19%. Averaged across species, cellulase application decreased (P < .05) silage NDF digestibility by 18%. Greater sugar and lower acetic acid, NH3 N, and NDF concentrations resulted in greater DMI of cellulase-treated silage than of control silage, when cellulase was combined

Synergism of cellulase, xylanase, and pectinase on hydrolyzing sugarcane bagasse resulting from different pretreatment technologies.

PubMed

Li, Jingbo; Zhou, Pengfei; Liu, Hongmei; Xiong, Chunjiang; Lin, Jianghai; Xiao, Wenjuan; Gong, Yingxue; Liu, Zehuan

2014-03-01

Sugarcane bagasse (SCB) resulting from different pretreatments was hydrolyzed by enzyme cocktails based on replacement of cellulase (Celluclast 1.5 L:Novozym 188=1FPU:4pNPGU) by xylanase or pectinase at different proportions. Lignin content of NaOH pretreated SCB and hemicellulose content of H2SO4 pretreated SCB were the lowest. NaOH pretreatment showed the best for monosaccharide production among the four pretreatments. Synergism was apparently observed between cellulase and xylanase for monosaccharide production from steam exploded SCB (SESB), NaOH, and H2O2 pretreated SCB. No synergism was observed between cellulase and pectinase for producing glucose. Additionally, no synergism was present when H2SO4 pretreated SCB was used. Replacement of 20% of the cellulase by xylanase enhanced the glucose yield by 6.6%, 8.8%, and 9.5% from SESB, NaOH, and H2O2 pretreated SCB, respectively. Degree of synergism between cellulase and xylanase had positive relationship with xylan content and was affected by hydrolysis time. Copyright © 2014 Elsevier Ltd. All rights reserved.

49 CFR 237.71 - Determination of bridge load capacities.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Determination of bridge load capacities. 237.71... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Capacity of Bridges § 237.71 Determination of bridge load capacities. (a) Each track owner shall determine the load capacity of each of its...

49 CFR 237.71 - Determination of bridge load capacities.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Determination of bridge load capacities. 237.71... ADMINISTRATION, DEPARTMENT OF TRANSPORTATION BRIDGE SAFETY STANDARDS Capacity of Bridges § 237.71 Determination of bridge load capacities. (a) Each track owner shall determine the load capacity of each of its...

Horizontal gene transfer of microbial cellulases into nematode genomes is associated with functional assimilation and gene turnover

PubMed Central

2011-01-01

Background Natural acquisition of novel genes from other organisms by horizontal or lateral gene transfer is well established for microorganisms. There is now growing evidence that horizontal gene transfer also plays important roles in the evolution of eukaryotes. Genome-sequencing and EST projects of plant and animal associated nematodes such as Brugia, Meloidogyne, Bursaphelenchus and Pristionchus indicate horizontal gene transfer as a key adaptation towards parasitism and pathogenicity. However, little is known about the functional activity and evolutionary longevity of genes acquired by horizontal gene transfer and the mechanisms favoring such processes. Results We examine the transfer of cellulase genes to the free-living and beetle-associated nematode Pristionchus pacificus, for which detailed phylogenetic knowledge is available, to address predictions by evolutionary theory for successful gene transfer. We used transcriptomics in seven Pristionchus species and three other related diplogastrid nematodes with a well-defined phylogenetic framework to study the evolution of ancestral cellulase genes acquired by horizontal gene transfer. We performed intra-species, inter-species and inter-genic analysis by comparing the transcriptomes of these ten species and tested for cellulase activity in each species. Species with cellulase genes in their transcriptome always exhibited cellulase activity indicating functional integration into the host's genome and biology. The phylogenetic profile of cellulase genes was congruent with the species phylogeny demonstrating gene longevity. Cellulase genes show notable turnover with elevated birth and death rates. Comparison by sequencing of three selected cellulase genes in 24 natural isolates of Pristionchus pacificus suggests these high evolutionary dynamics to be associated with copy number variations and positive selection. Conclusion We could demonstrate functional integration of acquired cellulase genes into the nematode

Horizontal gene transfer of microbial cellulases into nematode genomes is associated with functional assimilation and gene turnover.

PubMed

Mayer, Werner E; Schuster, Lisa N; Bartelmes, Gabi; Dieterich, Christoph; Sommer, Ralf J

2011-01-13

Natural acquisition of novel genes from other organisms by horizontal or lateral gene transfer is well established for microorganisms. There is now growing evidence that horizontal gene transfer also plays important roles in the evolution of eukaryotes. Genome-sequencing and EST projects of plant and animal associated nematodes such as Brugia, Meloidogyne, Bursaphelenchus and Pristionchus indicate horizontal gene transfer as a key adaptation towards parasitism and pathogenicity. However, little is known about the functional activity and evolutionary longevity of genes acquired by horizontal gene transfer and the mechanisms favoring such processes. We examine the transfer of cellulase genes to the free-living and beetle-associated nematode Pristionchus pacificus, for which detailed phylogenetic knowledge is available, to address predictions by evolutionary theory for successful gene transfer. We used transcriptomics in seven Pristionchus species and three other related diplogastrid nematodes with a well-defined phylogenetic framework to study the evolution of ancestral cellulase genes acquired by horizontal gene transfer. We performed intra-species, inter-species and inter-genic analysis by comparing the transcriptomes of these ten species and tested for cellulase activity in each species. Species with cellulase genes in their transcriptome always exhibited cellulase activity indicating functional integration into the host's genome and biology. The phylogenetic profile of cellulase genes was congruent with the species phylogeny demonstrating gene longevity. Cellulase genes show notable turnover with elevated birth and death rates. Comparison by sequencing of three selected cellulase genes in 24 natural isolates of Pristionchus pacificus suggests these high evolutionary dynamics to be associated with copy number variations and positive selection. We could demonstrate functional integration of acquired cellulase genes into the nematode's biology as predicted by theory

The putative protein methyltransferase LAE1 controls cellulase gene expression in Trichoderma reesei

PubMed Central

Seiboth, Bernhard; Karimi, Razieh Aghcheh; Phatale, Pallavi A; Linke, Rita; Hartl, Lukas; Sauer, Dominik G; Smith, Kristina M; Baker, Scott E; Freitag, Michael; Kubicek, Christian P

2012-01-01

Summary Trichoderma reesei is an industrial producer of enzymes that degrade lignocellulosic polysaccharides to soluble monomers, which can be fermented to biofuels. Here we show that the expression of genes for lignocellulose degradation are controlled by the orthologous T. reesei protein methyltransferase LAE1. In a lae1 deletion mutant we observed a complete loss of expression of all seven cellulases, auxiliary factors for cellulose degradation, β-glucosidases and xylanases were no longer expressed. Conversely, enhanced expression of lae1 resulted in significantly increased cellulase gene transcription. Lae1-modulated cellulase gene expression was dependent on the function of the general cellulase regulator XYR1, but also xyr1 expression was LAE1-dependent. LAE1 was also essential for conidiation of T. reesei. Chromatin immunoprecipitation followed by high-throughput sequencing (‘ChIP-seq’) showed that lae1 expression was not obviously correlated with H3K4 di- or trimethylation (indicative of active transcription) or H3K9 trimethylation (typical for heterochromatin regions) in CAZyme coding regions, suggesting that LAE1 does not affect CAZyme gene expression by directly modulating H3K4 or H3K9 methylation. Our data demonstrate that the putative protein methyltransferase LAE1 is essential for cellulase gene expression in T. reesei through mechanisms that remain to be identified. PMID:22554051

Cellulase-containing cell-free fermentate produced from microorganism ATCC 55702

DOEpatents

Dees, H. Craig

1997-12-16

Bacteria which produce large amounts of cellulase-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques.

Cellulase-containing cell-free fermentate produced from microorganism ATCC 55702

DOEpatents

Dees, H.C.

1997-12-16

Bacteria which produce large amounts of cellulase-containing cell-free fermentate have been identified. The original bacterium (ATCC 55703) was genetically altered using nitrosoguanidine (MNNG) treatment to produce the enhanced cellulase producing bacterium (ATCC 55702), which was identified through replicate plating. ATCC 55702 has improved characteristics and qualities for the degradation of cellulosic waste materials for fuel production, food processing, textile processing, and other industrial applications. ATCC 55702 is an improved bacterial host for genetic manipulations using recombinant DNA techniques, and is less likely to destroy genetic manipulations using standard mutagenesis techniques. 5 figs.

48 CFR 237.173 - Prohibition on interrogation of detainees by contractor personnel.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 48 Federal Acquisition Regulations System 3 2014-10-01 2014-10-01 false Prohibition on interrogation of detainees by contractor personnel. 237.173 Section 237.173 Federal Acquisition Regulations... SERVICE CONTRACTING Service Contracts-General 237.173 Prohibition on interrogation of detainees by...

48 CFR 237.173 - Prohibition on interrogation of detainees by contractor personnel.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Prohibition on interrogation of detainees by contractor personnel. 237.173 Section 237.173 Federal Acquisition Regulations... SERVICE CONTRACTING Service Contracts-General 237.173 Prohibition on interrogation of detainees by...

48 CFR 237.173 - Prohibition on interrogation of detainees by contractor personnel.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Prohibition on interrogation of detainees by contractor personnel. 237.173 Section 237.173 Federal Acquisition Regulations... SERVICE CONTRACTING Service Contracts-General 237.173 Prohibition on interrogation of detainees by...

48 CFR 237.173 - Prohibition on interrogation of detainees by contractor personnel.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Prohibition on interrogation of detainees by contractor personnel. 237.173 Section 237.173 Federal Acquisition Regulations... SERVICE CONTRACTING Service Contracts-General 237.173 Prohibition on interrogation of detainees by...

Mutagenesis and evaluation of cellulase properties and cellulose hydrolysis of Talaromyces piceus.

PubMed

He, Ronglin; Cai, Pengli; Wu, Gaihong; Zhang, Can; Zhang, Dongyuan; Chen, Shulin

2015-11-01

A fungal species with a high yield of β-glucosidase was isolated and identified as Talaromyces piceus 9-3 (anamorph: Penicillium piceum) by morphological and molecular characterization. Through dimethyl sulphate mutagenesis, the cellulase over-producing strain T. piceus H16 was obtained. The FPase activity and β-glucosidase activity of T. piceus H16 were 5.83 and 53.12 IU ml(-1) respectively--a 5.34- and 4.43-times improvement from the parent strain T. piceus 9-3. The optimum pH and temperature for enzyme activity were pH 5.0 and 50 °C for FPase activity and pH 5.0 and 55 °C for β-glucosidase activity, respectively. The cellulase were quite stable at 37 °C, only losing <10% of their initial activity after 24 h of incubation. Hydrolysis analysis results showed that a highly efficient synergistic effect was achieved by combining cellulase from T. piceus H16 with that from Trichoderma reesei RUT C30 on hydrolyzing different substrates due to the high β-glucosidase activity of T. piceus H16. These data suggest that T. piceus H16 can be used as a potential cellulase producer with good prospects.

48 CFR 1452.237-71 - Utilization of Woody Biomass.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Biomass. 1452.237-71 Section 1452.237-71 Federal Acquisition Regulations System DEPARTMENT OF THE INTERIOR... Utilization of Woody Biomass. As prescribed in § 1437.7202, insert the following clause: Utilization of Woody Biomass (MAY 2005) (a) The contractor may remove and utilize woody biomass, if: (1) Project work is...

Strong cellulase inhibitors from the hydrothermal pretreatment of wheat straw

PubMed Central

2013-01-01

Background The use of the enzymatic hydrolysis of lignocellulose with subsequent fermentation to ethanol provides a green alternative for the production of transportation fuels. Because of its recalcitrant nature, the lignocellulosic biomass must be pretreated before enzymatic hydrolysis. However, the pretreatment often results in the formation of compounds that are inhibitory for the enzymes or fermenting organism. Although well recognized, little quantitative information on the inhibition of individual cellulase components by identified inhibitors is available. Results Strong cellulase inhibitors were separated from the liquid fraction of the hydrothermal pretreatment of wheat straw. HPLC and mass-spectroscopy analyses confirmed that the inhibitors were oligosaccharides (inhibitory oligosaccharides, IOS) with a degree of polymerization from 7 to 16. The IOS are composed of a mixture of xylo- (XOS) and gluco-oligosaccharides (GOS). We propose that XOS and GOS are the fragments of the xylan backbone and mixed-linkage β-glucans, respectively. The IOS were approximately 100 times stronger inhibitors for Trichoderma reesei cellobiohydrolases (CBHs) than cellobiose, which is one of the strongest inhibitors of these enzymes reported to date. Inhibition of endoglucanases (EGs) by IOS was weaker than that of CBHs. Most of the tested cellulases and hemicellulases were able to slowly degrade IOS and reduce the inhibitory power of the liquid fraction to some extent. The most efficient single enzyme component here was T. reesei EG TrCel7B. Although reduced by the enzyme treatment, the residual inhibitory power of IOS and the liquid fraction was strong enough to silence the major component of the T. reesei cellulase system, CBH TrCel7A. Conclusions The cellulase inhibitors described here may be responsible for the poor yields from the enzymatic conversion of the whole slurries from lignocellulose pretreatment under conditions that do not favor complete degradation of

Optimization of a natural medium for cellulase by a marine Aspergillus niger using response surface methodology.

PubMed

Xue, Dong-Sheng; Chen, Hui-Yin; Lin, Dong-Qiang; Guan, Yi-Xin; Yao, Shan-Jing

2012-08-01

The components of a natural medium were optimized to produce cellulase from a marine Aspergillus niger under solid state fermentation conditions by response surface methodology. Eichhornia crassipes and natural seawater were used as a major substrate and a source of mineral salts, respectively. Mineral salts of natural seawater could increase cellulase production. Raw corn cob and raw rice straw showed a significant positive effect on cellulase production. The optimum natural medium consisted of 76.9 % E. crassipes (w/w), 8.9 % raw corn cob (w/w), 3.5 % raw rice straw (w/w), 10.7 % raw wheat bran (w/w), and natural seawater (2.33 times the weight of the dry substrates). Incubation for 96 h in the natural medium increased the biomass to the maximum. The cellulase production was 17.80 U/g the dry weight of substrates after incubation for 144 h. The natural medium avoided supplying chemicals and pretreating substrates. It is promising for future practical fermentation of environment-friendly producing cellulase.

Effect of bisulfite treatment on composition, structure, enzymatic hydrolysis and cellulase adsorption profiles of sugarcane bagasse.

PubMed

Liu, Z J; Lan, T Q; Li, H; Gao, X; Zhang, H

2017-01-01

The effect of sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) on composition, structure, enzymatic hydrolysis and cellulase adsorption profiles of sugarcane bagasse (SCB) was investigated. SPORL gave a higher SCB hydrolysis yield (85.33%) compared to dilute acid pretreatment (DA) (64.39%). The SEM pictures showed that SPORL SCB structure became more disordered and looser, suggesting SPORL SCB was more accessible to cellulase. The zeta potential of SPORL SCB suspension (-21.89mV) was significantly different from that of DA SCB (-12.87mV), which demonstrated the lignin in SPORL SCB was more hydrophilic. With regard to cellulase adsorption profiles, SPORL SCB had a lower non-productive adsorption (14.87mg/glignin) and a higher productive adsorption (37.67 mg/gcarbohydrate) compared with DA SCB (17.05mg/glignin; 25.79mg/gcarbohydrate). These results indicated that SPORL SCB had better accessibility to cellulase and the higher productive cellulase adsorption of SPORL SCB had improved hydrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

48 CFR 52.237-2 - Protection of Government Buildings, Equipment, and Vegetation.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Buildings, Equipment, and Vegetation. 52.237-2 Section 52.237-2 Federal Acquisition Regulations System... Text of Provisions and Clauses 52.237-2 Protection of Government Buildings, Equipment, and Vegetation...: Protection of Government Buildings, Equipment, and Vegetation (APR 1984) The Contractor shall use reasonable...

Biomining active cellulases from a mining bioremediation system.

PubMed

Mewis, Keith; Armstrong, Zachary; Song, Young C; Baldwin, Susan A; Withers, Stephen G; Hallam, Steven J

2013-09-20

Functional metagenomics has emerged as a powerful method for gene model validation and enzyme discovery from natural and human engineered ecosystems. Here we report development of a high-throughput functional metagenomic screen incorporating bioinformatic and biochemical analyses features. A fosmid library containing 6144 clones sourced from a mining bioremediation system was screened for cellulase activity using 2,4-dinitrophenyl β-cellobioside, a previously proven cellulose model substrate. Fifteen active clones were recovered and fully sequenced revealing 9 unique clones with the ability to hydrolyse 1,4-β-D-glucosidic linkages. Transposon mutagenesis identified genes belonging to glycoside hydrolase (GH) 1, 3, or 5 as necessary for mediating this activity. Reference trees for GH 1, 3, and 5 families were generated from sequences in the CAZy database for automated phylogenetic analysis of fosmid end and active clone sequences revealing known and novel cellulase encoding genes. Active cellulase genes recovered in functional screens were subcloned into inducible high copy plasmids, expressed and purified to determine enzymatic properties including thermostability, pH optima, and substrate specificity. The workflow described here provides a general paradigm for recovery and characterization of microbially derived genes and gene products based on genetic logic and contemporary screening technologies developed for model organismal systems. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

49 CFR 234.237 - Reverse switch cut-out circuit.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Reverse switch cut-out circuit. 234.237 Section... Maintenance, Inspection, and Testing Maintenance Standards § 234.237 Reverse switch cut-out circuit. A switch... system circuitry, shall be maintained so that the warning system can only be cut out when the switch...

49 CFR 234.237 - Reverse switch cut-out circuit.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Reverse switch cut-out circuit. 234.237 Section... Maintenance, Inspection, and Testing Maintenance Standards § 234.237 Reverse switch cut-out circuit. A switch... system circuitry, shall be maintained so that the warning system can only be cut out when the switch...

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 4 2010-10-01 2010-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 4 2011-10-01 2011-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

49 CFR 237.133 - Supervision of repairs and modifications.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Supervision of repairs and modifications. 237.133... Supervision of repairs and modifications. Each repair or modification pursuant to this part shall be performed under the immediate supervision of a railroad bridge supervisor as defined in § 237.55 of this part who...

48 CFR 237.7101 - Solicitation provisions and contract clauses.

Code of Federal Regulations, 2010 CFR

2010-10-01

... clause at 252.237-7015, Loss or Damage (Weight of Articles), in solicitations and contracts for laundry..., Instruction to Offerors (Bulk Weight), in solicitations for laundry services to be provided on a bulk weight basis. (c) Use the clause at 252.237-7014, Loss or Damage (Count-of-Articles), in solicitations and...

48 CFR 237.7200 - Scope.

Code of Federal Regulations, 2010 CFR

2010-10-01

... agreements, i.e., payment by the Government of partial tuition under the off-duty educational program. (b) As... DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING Educational Service Agreements 237.7200 Scope. (a) This subpart prescribes acquisition procedures for educational services from schools...

48 CFR 237.7200 - Scope.

Code of Federal Regulations, 2011 CFR

2011-10-01

... agreements, i.e., payment by the Government of partial tuition under the off-duty educational program. (b) As... DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING Educational Service Agreements 237.7200 Scope. (a) This subpart prescribes acquisition procedures for educational services from schools...

Neutron induced fission of 237Np - status, challenges and opportunities

NASA Astrophysics Data System (ADS)

Ruskov, Ivan; Goverdovski, Andrei; Furman, Walter; Kopatch, Yury; Shcherbakov, Oleg; Hambsch, Franz-Josef; Oberstedt, Stephan; Oberstedt, Andreas

2018-03-01

Nowadays, there is an increased interest in a complete study of the neutron-induced fission of 237Np. This is due to the need of accurate and reliable nuclear data for nuclear science and technology. 237Np is generated (and accumulated) in the nuclear reactor core during reactor operation. As one of the most abundant long-lived isotopes in spent fuel ("waste"), the incineration of 237Np becomes an important issue. One scenario for burning of 237Np and other radio-toxic minor actinides suggests they are to be mixed into the fuel of future fast-neutron reactors, employing the so-called transmutation and partitioning technology. For testing present fission models, which are at the basis of new generation nuclear reactor developments, highly accurate and detailed neutron-induced nuclear reaction data is needed. However, the EXFOR nuclear database for 237Np on neutron-induced capture cross-section, σγ, and fission cross-section, σf, as well as on the characteristics of capture and fission resonance parameters (Γγ, Γf, σoΓf, fragments mass-energy yield distributions, multiplicities of neutrons vn and γ-rays vγ), has not been updated for decades.

5 CFR 838.237 - Death of the former spouse.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 5 Administrative Personnel 2 2010-01-01 2010-01-01 false Death of the former spouse. 838.237... Affecting Employee Annuities Payment Procedures § 838.237 Death of the former spouse. (a) Unless the court... annuity terminates on the last day of the month before the death of the former spouse, and the former...

49 CFR 234.237 - Reverse switch cut-out circuit.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 4 2013-10-01 2013-10-01 false Reverse switch cut-out circuit. 234.237 Section....237 Reverse switch cut-out circuit. A switch, when equipped with a switch circuit controller connected... warning system can only be cut out when the switch point is within one-half inch of full reverse position. ...

49 CFR 234.237 - Reverse switch cut-out circuit.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Reverse switch cut-out circuit. 234.237 Section....237 Reverse switch cut-out circuit. A switch, when equipped with a switch circuit controller connected... warning system can only be cut out when the switch point is within one-half inch of full reverse position. ...

49 CFR 234.237 - Reverse switch cut-out circuit.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 4 2012-10-01 2012-10-01 false Reverse switch cut-out circuit. 234.237 Section....237 Reverse switch cut-out circuit. A switch, when equipped with a switch circuit controller connected... warning system can only be cut out when the switch point is within one-half inch of full reverse position. ...

5 CFR 838.237 - Death of the former spouse.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 5 Administrative Personnel 2 2011-01-01 2011-01-01 false Death of the former spouse. 838.237... Affecting Employee Annuities Payment Procedures § 838.237 Death of the former spouse. (a) Unless the court... annuity terminates on the last day of the month before the death of the former spouse, and the former...

5 CFR 838.237 - Death of the former spouse.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 5 Administrative Personnel 2 2013-01-01 2013-01-01 false Death of the former spouse. 838.237... Affecting Employee Annuities Payment Procedures § 838.237 Death of the former spouse. (a) Unless the court... annuity terminates on the last day of the month before the death of the former spouse, and the former...

5 CFR 838.237 - Death of the former spouse.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 5 Administrative Personnel 2 2014-01-01 2014-01-01 false Death of the former spouse. 838.237... Affecting Employee Annuities Payment Procedures § 838.237 Death of the former spouse. (a) Unless the court... annuity terminates on the last day of the month before the death of the former spouse, and the former...

5 CFR 838.237 - Death of the former spouse.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 5 Administrative Personnel 2 2012-01-01 2012-01-01 false Death of the former spouse. 838.237... Affecting Employee Annuities Payment Procedures § 838.237 Death of the former spouse. (a) Unless the court... annuity terminates on the last day of the month before the death of the former spouse, and the former...

The effect of cellulases on the biodegradation and morphology of naturally colored cotton fibers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Evans, B.R.; Lee, I.; Woodward, J.

We have investigated the effect of cellulases on the biodegradation and structure of natural colored cotton (Foxfibre{reg_sign}). Compared to the white cotton and palo verde (sage green) varieties, buffalo (mocha brown) and coyote (reddish brown) varieties were quite resistant to hydrolysis by Trichoderma reesei celluclast and purified cellobiohydrolase I (CBH I) under the conditions of the assay, but binding of CBH I to buffalo cotton was unaffected. Sodium hydroxide extracts of all the colored cotton varieties were found to be strong inhibitors of cellulase activity and the buffalo cotton was labile in that the inhibitory effect decreased over time inmore » the presence of cellulase; incubation of {beta}-glucosidase with the extract also decreased the inhibition. The chemical composition of the inhibitor is currently under investigation. Atomic force microscopy of the colored cotton fibers with bound cellulase components should prove useful in the context of elucidating the effect of binding on the morphology of cellulose fibers.« less

48 CFR 352.237-71 - Crime Control Act-reporting of child abuse.

Code of Federal Regulations, 2010 CFR

2010-10-01

... mental injury, sexual abuse or exploitation, or negligent treatment of a child. (c) Accordingly, any...-reporting of child abuse. 352.237-71 Section 352.237-71 Federal Acquisition Regulations System HEALTH AND... Clauses 352.237-71 Crime Control Act—reporting of child abuse. As prescribed in 337.103-70(b), the...

Enhanced cellulase hydrolysis of eucalyptus waste fibers from pulp mill by Tween80-assisted ferric chloride pretreatment.

PubMed

Chen, Liheng; Fu, Shiyu

2013-04-03

Pretreatment combining FeCl3 and Tween80 was performed for cellulose-to-ethanol conversion of eucalyptus alkaline peroxide mechanical pulping waste fibers (EAWFs). The FeCl3 pretreatment alone showed a good effect on the enzymatic hydrolysis of EAWFs, but inhibited enzyme activity to some extent. A surfactant, Tween80, added during FeCl3 pretreatment was shown to significantly enhance enzyme reaction by eluting enzymatic inhibitors such as iron(III) that are present at the surface of the pretreated biomass. Treatment temperature, liquid-solid ratio, treatment time, FeCl3 concentration, and Tween80 dosage for pretreatment were optimized as follows: 180 °C, 8:1, 30 min, 0.15 mol/L, and 1% (w/v). Pretreated EAWFs under such optimal conditions provided enzymatic glucose (based on 100 g of oven-dried feedstock) and substrate enzymatic digestibility of EAWFs of 34.8 g and 91.3% after 72 h of enzymatic hydrolysis, respectively, with an initial cellulase loading of 20 FPU/g substrate.

Enhanced cellulase production in Trichoderma reesei RUT C30 via constitution of minimal transcriptional activators.

PubMed

Zhang, Jiajia; Zhang, Guoxiu; Wang, Wei; Wang, Wei; Wei, Dongzhi

2018-05-17

Cellulase can convert lignocellulosic feedstocks into fermentable sugars, which can be used for the industrial production of biofuels and chemicals. The high cost of cellulase production remains a challenge for lignocellulose breakdown. Trichoderma reesei RUT C30 serves as a well-known industrial workhorse for cellulase production. Therefore, the enhancement of cellulase production by T. reesei RUT C30 is of great importance. Two sets of novel minimal transcriptional activators (DBD ace2 -VP16 and DBD cre1 -VP16) were designed and expressed in T. reesei RUT C30. Expression of DBD ace2 -VP16 and DBD cre1 -VP16 improved cellulase production under induction (avicel or lactose) and repression (glucose) conditions, respectively. The strain T MTA66 under avicel and T MTA139 under glucose with the highest cellulase activities outperformed other transformants and the parental strain under the corresponding conditions. For T MTA66 strains, the highest FPase activity was approximately 1.3-fold greater than that of the parental strain RUT C30 at 120 h of cultivation in a shake flask using avicel as the sole carbon source. The FPase activity (U/mg biomass) in T MTA139 strains was approximately 26.5-fold higher than that of the parental strain RUT C30 at 72 h of cultivation in a shake flask using glucose as the sole carbon source. Furthermore, the crude enzymes produced in the 7-L fermenter from T MTA66 and T MTA139 supplemented with commercial β-glucosidase hydrolyzed pretreated corn stover effectively. These results show that replacing natural transcription factors with minimal transcriptional activators is a powerful strategy to enhance cellulase production in T. reesei. Our current study also offers an alternative genetic engineering strategy for the enhanced production of industrial products by other fungi.

Lignocellulose-Adapted Endo-Cellulase Producing Streptomyces Strains for Bioconversion of Cellulose-Based Materials.

PubMed

Ventorino, Valeria; Ionata, Elena; Birolo, Leila; Montella, Salvatore; Marcolongo, Loredana; de Chiaro, Addolorata; Espresso, Francesco; Faraco, Vincenza; Pepe, Olimpia

2016-01-01

Twenty-four Actinobacteria strains, isolated from Arundo donax, Eucalyptus camaldulensis and Populus nigra biomass during natural biodegradation and with potential enzymatic activities specific for the degradation of lignocellulosic materials, were identified by a polyphasic approach. All strains belonged to the genus Streptomyces ( S .) and in particular, the most highly represented species was Streptomyces argenteolus representing 50% of strains, while 8 strains were identified as Streptomyces flavogriseus (synonym S. flavovirens ) and Streptomyces fimicarius (synonyms Streptomyces acrimycini, Streptomyces baarnensis, Streptomyces caviscabies , and Streptomyces flavofuscus ), and the other four strains belonged to the species Streptomyces drozdowiczii, Streptomyces rubrogriseus, Streptomyces albolongus , and Streptomyces ambofaciens . Moreover, all Streptomyces strains, tested for endo and exo-cellulase, cellobiase, xylanase, pectinase, ligninase, peroxidase, and laccase activities using qualitative and semi-quantitative methods on solid growth medium, exhibited multiple enzymatic activities (from three to six). The 24 strains were further screened for endo-cellulase activity in liquid growth medium and the four best endo-cellulase producers ( S. argenteolus AE58P, S. argenteolus AE710A, S. argenteolus AE82P, and S. argenteolus AP51A) were subjected to partial characterization and their enzymatic crude extracts adopted to perform saccharification experiments on A. donax pretreated biomass. The degree of cellulose and xylan hydrolysis was evaluated by determining the kinetics of glucose and xylose release during 72 h incubation at 50°C from the pretreated biomass in the presence of cellulose degrading enzymes (cellulase and β-glucosidase) and xylan related activities (xylanase and β-xylosidase). The experiments were carried out utilizing the endo-cellulase activities from the selected S. argenteolus strains supplemented with commercial β-gucosidase and

Cellulase Linkers Are Optimized Based on Domain Type and Function: Insights from Sequence Analysis, Biophysical Measurements, and Molecular Simulation

PubMed Central

Sammond, Deanne W.; Payne, Christina M.; Brunecky, Roman; Himmel, Michael E.; Crowley, Michael F.; Beckham, Gregg T.

2012-01-01

Cellulase enzymes deconstruct cellulose to glucose, and are often comprised of glycosylated linkers connecting glycoside hydrolases (GHs) to carbohydrate-binding modules (CBMs). Although linker modifications can alter cellulase activity, the functional role of linkers beyond domain connectivity remains unknown. Here we investigate cellulase linkers connecting GH Family 6 or 7 catalytic domains to Family 1 or 2 CBMs, from both bacterial and eukaryotic cellulases to identify conserved characteristics potentially related to function. Sequence analysis suggests that the linker lengths between structured domains are optimized based on the GH domain and CBM type, such that linker length may be important for activity. Longer linkers are observed in eukaryotic GH Family 6 cellulases compared to GH Family 7 cellulases. Bacterial GH Family 6 cellulases are found with structured domains in either N to C terminal order, and similar linker lengths suggest there is no effect of domain order on length. O-glycosylation is uniformly distributed across linkers, suggesting that glycans are required along entire linker lengths for proteolysis protection and, as suggested by simulation, for extension. Sequence comparisons show that proline content for bacterial linkers is more than double that observed in eukaryotic linkers, but with fewer putative O-glycan sites, suggesting alternative methods for extension. Conversely, near linker termini where linkers connect to structured domains, O-glycosylation sites are observed less frequently, whereas glycines are more prevalent, suggesting the need for flexibility to achieve proper domain orientations. Putative N-glycosylation sites are quite rare in cellulase linkers, while an N-P motif, which strongly disfavors the attachment of N-glycans, is commonly observed. These results suggest that linkers exhibit features that are likely tailored for optimal function, despite possessing low sequence identity. This study suggests that cellulase

Enhancement of CO/sub 2/ and ethylene production and cellulase activity by glyphosate in Phaseolus vulgaris

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abu-Irmaileh, B.E.; Jordan, L.S.; Kumamoto, J.

1979-01-01

The effect of glyphosate (N-(phosphonomethyl)glycine) on carbon dioxide. (CO/sub 2/) levels, ethylene production, and cellulase activity was investigated. Production of ethylene increased within 12 h and CO/sub 2/ increased within 24 h when 12-day-old bean plants (Phaseolus vulgaris L. Red Kidney) were treated with 20 mM isopropylamine salt of glyphosate. The CO/sub 2/ cycled for 3 days and then increased around treated plants. Specific activity of cellulase was increased in debladed bean seedlings that had been retreated with 20 mM isopropylamine salt of glyphosate. Cellulase enhancement was detected 2 days after the pretreated plants were debladed. Glyphosate-enhanced ethylene production maymore » have increased the cellulase activity. 24 references, 3 figures.« less

Characterization of a GHF45 cellulase, AkEG21, from the common sea hare Aplysia kurodai

NASA Astrophysics Data System (ADS)

Rahman, Mohammad; Inoue, Akira; Ojima, Takao

2014-08-01

The common sea hare Aplysia kurodai is known to be a good source for the enzymes degrading seaweed polysaccharides. Recently four cellulases, i.e., 95 kDa, 66 kDa, 45 kDa and 21 kDa enzymes, were isolated from A. kurodai (Tsuji et al., PLoS ONE, 8, e65418, 2013). The former three cellulases were regarded as glycosyl-hydrolase-family 9 (GHF9) enzymes, while the 21 kDa cellulase was suggested to be a GHF45 enzyme. The 21 kDa cellulase was significantly heat stable, and appeared to be advantageous in performing heterogeneous expression and protein-engineering study. In the present study, we determined some enzymatic properties of the 21 kDa cellulase and cloned its cDNA to provide the basis for the protein engineering study of this cellulase. The purified 21 kDa enzyme, termed AkEG21 in the present study, hydrolyzed carboxymethyl cellulose with an optimal pH and temperature at 4.5 and 40oC, respectively. AkEG21 was considerably heat-stable, i.e., it was not inactivated by the incubation at 55oC for 30 min. AkEG21 degraded phosphoric-acid-swollen cellulose producing cellotriose and cellobiose as major end products but hardly degraded oligosaccharides smaller than tetrasaccharide. This indicated that AkEG21 is an endolytic ?-1,4-glucanase (EC 3.2.1.4). A cDNA of 1,013 bp encoding AkEG21 was amplified by PCR and the amino-acid sequence of 197 residues was deduced. The sequence comprised the initiation Met, the putative signal peptide of 16 residues for secretion and the catalytic domain of 180 residues, which lined from the N-terminus in this order. The sequence of the catalytic domain showed 47-62% amino-acid identities to those of GHF45 cellulases reported in other mollusks. Both the catalytic residues and the N-glycosylation residues known in other GHF45 cellulases were conserved in AkEG21. Phylogenetic analysis for the amino-acid sequences suggested the close relation between AkEG21 and fungal GHF45 cellulases.

Identification of a haloalkaliphilic and thermostable cellulase with improved ionic liquid tolerance

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Tao; Datta, Supratim; Eichler, Jerry

2011-02-17

Some ionic liquids (ILs) have been shown to be very effective solvents for biomass pretreatment. It is known that some ILs can have a strong inhibitory effect on fungal cellulases, making the digestion of cellulose inefficient in the presence of ILs. The identification of IL-tolerant enzymes that could be produced as a cellulase cocktail would reduce the costs and water use requirements of the IL pretreatment process. Due to their adaptation to high salinity environments, halophilic enzymes are hypothesized to be good candidates for screening and identifying IL-resistant cellulases. Using a genome-based approach, we have identified and characterized a halophilicmore » cellulase (Hu-CBH1) from the halophilic archaeon, Halorhabdus utahensis. Hu-CBH1 is present in a gene cluster containing multiple putative cellulolytic enzymes. Sequence and theoretical structure analysis indicate that Hu-CBH1 is highly enriched with negatively charged acidic amino acids on the surface, which may form a solvation shell that may stabilize the enzyme, through interaction with salt ions and/or water molecules. Hu-CBH1 is a heat tolerant haloalkaliphilic cellulase and is active in salt concentrations up to 5 M NaCl. In high salt buffer, Hu-CBH1 can tolerate alkali (pH 11.5) conditions and, more importantly, is tolerant to high levels (20percent w/w) of ILs, including 1-allyl-3-methylimidazolium chloride ([Amim]Cl). Interestingly, the tolerances to heat, alkali and ILs are found to be salt-dependent, suggesting that the enzyme is stabilized by the presence of salt. Our results indicate that halophilic enzymes are good candidates for the screening of IL-tolerant cellulolytic enzymes.« less

Characterization of Cellulase Enzyme Inhibitors Formed During the Chemical Pretreatments of Rice Straw

NASA Astrophysics Data System (ADS)

Rajan, Kalavathy

Production of fuels and chemicals from a renewable and inexpensive resource such as lignocellulosic biomass is a lucrative and sustainable option for the advanced biofuel and bio-based chemical platform. Agricultural residues constitute the bulk of potential feedstock available for cellulosic fuel production. On a global scale, rice straw is the largest source of agricultural residues and is therefore an ideal crop model for biomass deconstruction studies. Lignocellulosic biofuel production involves the processes of biomass conditioning, enzymatic saccharification, microbial fermentation and ethanol distillation, and one of the major factors affecting its techno-economic feasibility is the biomass recalcitrance to enzymatic saccharification. Preconditioning of lignocellulosic biomass, using chemical, physico-chemical, mechanical and biological pretreatments, is often practiced such that biomass becomes available to downstream processing. Pretreatments, such as dilute acid and hot water, are effective means of biomass conversion. However, despite their processing importance, preconditioning biomass also results in the production of carbohydrate and lignin degradation products that are inhibitory to downstream saccharification enzymes. The saccharification enzyme cocktail is made up of endo-cellulase, exo-cellulase and beta-glucosidase enzymes, whose role is to cleave cellulose polymers into glucose monomers. Specifically, endo-cellulase and exo-cellulase enzymes cleave cellulose chains in the middle and at the end, resulting in cellobiose molecules, which are hydrolyzed into glucose by beta-glucosidase. Unfortunately, degradation compounds generated during pretreatment inhibit the saccharification enzyme cocktail. Various research groups have identified specific classes of inhibitors formed during biomass pretreatment and have studied their inhibitory effect on the saccharification cocktail. These various research groups prepared surrogate solutions in an attempt to

A new earthworm cellulase and its possible role in the innate immunity.

PubMed

Park, In Yong; Cha, Ju Roung; Ok, Suk-Mi; Shin, Chuog; Kim, Jin-Se; Kwak, Hee-Jin; Yu, Yun-Sang; Kim, Yu-Kyung; Medina, Brenda; Cho, Sung-Jin; Park, Soon Cheol

2017-02-01

A new endogenous cellulase (Ean-EG) from the earthworm, Eisenia andrei and its expression pattern are demonstrated. Based on a deduced amino acid sequence, the open reading frame (ORF) of Ean-EG consisted of 1368 bps corresponding to a polypeptide of 456 amino acid residues in which is contained the conserved region specific to GHF9 that has the essential amino acid residues for enzyme activity. In multiple alignments and phylogenetic analysis, the deduced amino acid sequence of Ean- EG showed the highest sequence similarity (about 79%) to that of an annelid (Pheretima hilgendorfi) and could be clustered together with other GHF9 cellulases, indicating that Ean-EG could be categorized as a member of the GHF9 to which most animal cellulases belong. The histological expression pattern of Ean-EG mRNA using in situ hybridization revealed that the most distinct expression was observed in epithelial cells with positive hybridization signal in epidermis, chloragogen tissue cells, coelomic cell-aggregate, and even blood vessel, which could strongly support the fact that at least in the earthworm, Eisenia andrei, cellulase function must not be limited to digestive process but be possibly extended to the innate immunity. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enhancement in ionic liquid tolerance of cellulase immobilized on PEGylated graphene oxide nanosheets: Application in saccharification of lignocellulose.

PubMed

Xu, Jiaxing; Sheng, Zhenhuan; Wang, Xinfeng; Liu, Xiaoyan; Xia, Jun; Xiong, Peng; He, Bingfang

2016-01-01

The objective of the present work was to improve ionic liquid (IL) tolerance of cellulase based on the exploration of functional nanoscale carriers for potential application in lignocellulosic biorefinery. PEGylated graphene oxide (GO) composite was successfully fabricated by chemical binding of 4-arm-PEG-NH2 and GO and applied to the immobilization of cellulase. The PEGylated GO-Cellulase retained 61% of the initial activity in 25% (w/v) 1-butyl-3-methylimidazolium chloride ([Bmim][Cl]) while free cellulase only retained 2%. The IL stability was enhanced more than 30 times. The relatively minor change in Km value (from 2.7 to 3.2mgmL(-1)) after the immobilization suggested that PEGylated GO-Cellulase was capable of closely mimicking the performance of free enzyme. After treating rice straw with [Bmim][Cl] and dilution to a final IL concentration of 15% (w/v), the slurry was directly hydrolyzed using PEGylated GO-Cellulase without IL removing and a high hydrolysis rate of 87% was achieved. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of xylanase supplementation of cellulase on digestion of corn stover solids prepared by leading pretreatment technologies.

PubMed

Kumar, Rajeev; Wyman, Charles E

2009-09-01

Solids resulting from pretreatment of corn stover by ammonia fiber expansion (AFEX), ammonia recycled percolation (ARP), controlled pH, dilute acid, lime, and sulfur dioxide (SO(2)) technologies were hydrolyzed by enzyme cocktails based on cellulase supplemented with beta-glucosidase at an activity ratio of 1:2, respectively, and augmented with up to 11.0 g xylanase protein/g cellulase protein for combined cellulase and beta-glucosidase mass loadings of 14.5 and 29.0 mg protein (about 7.5 and 15 FPU, respectively)/g of original potential glucose. It was found that glucose release increased nearly linearly with residual xylose removal by enzymes for all pretreatments despite substantial differences in their relative yields. The ratio of the fraction of glucan removed by enzymes to that for xylose was defined as leverage and correlated statistically at two combined cellulase and beta-glucosidase mass loadings with pretreatment type. However, no direct relationship was found between leverage and solid features following different pretreatments such as residual xylan or acetyl content. However, acetyl content not only affected how xylanase impacted cellulase action but also enhanced accessibility of cellulose and/or cellulase effectiveness, as determined by hydrolysis with purified CBHI (Cel7A). Statistical modeling showed that cellulose crystallinity, among the main substrate features, played a vital role in cellulase-xylanase interactions, and a mechanism is suggested to explain the incremental increase in glucose release with xylanase supplementation.

Fractionation and cellulase treatment for enhancing the properties of kraft-based dissolving pulp.

PubMed

Duan, Chao; Wang, Xinqi; Zhang, YanLing; Xu, Yongjian; Ni, Yonghao

2017-01-01

The aim of this study was to investigate a combined process involving pulp fractionation and cellulase treatment of each fraction for improving the molecular weight distribution (MWD) and reactivity of a kraft-based dissolving pulp. Three pulp fractions, namely long-fiber, mid-fiber and short-fiber fractions (LF, MF and SF, respectively), were used as the substrates. The results showed that the SF had the highest accessibility, lowest viscosity, and highest cellulase adsorption capacity, while the opposite was true for the LF. At a given viscosity, the combined process led to a lower polydispersity index (3.71 vs 4.98) and a higher Fock reactivity (85.6% vs 76.3%), in comparison to the conventional single-stage cellulase treatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Catalysis of Rice Straw Hydrolysis by the Combination of Immobilized Cellulase from Aspergillus niger on β-Cyclodextrin-Fe3O4 Nanoparticles and Ionic Liquid

PubMed Central

Huang, Po-Jung; Chang, Ken-Lin; Chen, Shui-Tein

2015-01-01

Cellulase from Aspergillus niger was immobilized onto β-cyclodextrin-conjugated magnetic particles by silanization and reductive amidation. The immobilized cellulase gained supermagnetism due to the magnetic nanoparticles. Ninety percent of cellulase was immobilized, but the activity of immobilized cellulase decreased by 10%. In this study, ionic liquid (1-butyl-3-methylimidazolium chloride) was introduced into the hydrolytic process because the original reaction was a solid-solid reaction. The activity of immobilized cellulase was improved from 54.87 to 59.11 U g immobilized cellulase−1 at an ionic liquid concentration of 200 mM. Using immobilized cellulase and ionic liquid in the hydrolysis of rice straw, the initial reaction rate was increased from 1.629 to 2.739 g h−1 L−1. One of the advantages of immobilized cellulase is high reusability—it was usable for a total of 16 times in this study. Compared with free cellulase, magnetized cellulase can be recycled by magnetic field and the activity of immobilized cellulase was shown to remain at 85% of free cellulase without denaturation under a high concentration of glucose (15 g L−1). Therefore, immobilized cellulase can hydrolyze rice straw continuously compared with free cellulase. The amount of harvested glucose can be up to twentyfold higher than that from the hydrolysis by free cellulase. PMID:25874210

Determination of the cellulase activity distribution in Clostridium thermocellum and Caldicellulosiruptor obsidiansis cultures using a fluorescent substrate

DOE PAGES

Morrell-Falvey, Jennifer L.; Elkins, James G.; Wang, Zhi-Wu

2015-05-30

This study took advantage of resorufin cellobioside as a fluorescent substrate to determine the distribution of cellulase activity in cellulosic biomass fermentation systems. Cellulolytic biofilms were found to express nearly four orders greater cellulase activity compared to planktonic cultures of Clostridium thermocellum and Caldicellulosiruptor obsidiansis, which can be primarily attributed to the high cell concentration and surface attachment. The formation of biofilms results in cellulases being secreted close to their substrates, which appears to be an energetically favorable stategy for insoluble substrate utilization. For the same reason, cellulases should be closely associated with the surfaces of suspended cell in solublemore » substrate-fed culture, which has been verified with cellobiose-fed cultures of C. thermocellum and C. obsidiansis. This study addressed the importance of cellulase activity distribution in cellulosic biomass fermentation, and provided theoretical foundation for the leading role of biofilm in cellulose degradation. System optimization and reactor designs that promote biofilmformation in cellulosic biomass hydrolysismay promise an improved cellulosic biofuel process.« less

The effect of alkaline pretreatment methods on cellulose structure and accessibility

DOE PAGES

Bali, Garima; Meng, Xianzhi; Deneff, Jacob I.; ...

2014-11-24

The effects of different alkaline pretreatments on cellulose structural features and accessibility are compared and correlated with the enzymatic hydrolysis of Populus. The pretreatments are shown to modify polysaccharides and lignin content to enhance the accessibility for cellulase enzymes. The highest increase in the cellulose accessibility was observed in dilute sodium hydroxide, followed by methods using ammonia soaking and lime (Ca(OH) 2). The biggest increase of cellulose accessibility occurs during the first 10 min of pretreatment, with further increases at a slower rate as severity increases. Low temperature ammonia soaking at longer residence times dissolved a major portion of hemicellulosemore » and exhibited higher cellulose accessibility than high temperature soaking. Moreover, the most significant reduction of degree of polymerization (DP) occurred for dilute sodium hydroxide (NaOH) and ammonia pretreated Populus samples. The study thus identifies important cellulose structural features and relevant parameters related to biomass recalcitrance.« less

Bioprospecting of functional cellulases from metagenome for second generation biofuel production: a review.

PubMed

Tiwari, Rameshwar; Nain, Lata; Labrou, Nikolaos E; Shukla, Pratyoosh

2018-03-01

Second generation biofuel production has been appeared as a sustainable and alternative energy option. The ultimate aim is the development of an industrially feasible and economic conversion process of lignocellulosic biomass into biofuel molecules. Since, cellulose is the most abundant biopolymer and also represented as the photosynthetically fixed form of carbon, the efficient hydrolysis of cellulose is the most important step towards the development of a sustainable biofuel production process. The enzymatic hydrolysis of cellulose by suites of hydrolytic enzymes underlines the importance of cellulase enzyme system in whole hydrolysis process. However, the selection of the suitable cellulolytic enzymes with enhanced activities remains a challenge for the biorefinery industry to obtain efficient enzymatic hydrolysis of biomass. The present review focuses on deciphering the novel and effective cellulases from different environmental niches by unculturable metagenomic approaches. Furthermore, a comprehensive functional aspect of cellulases is also presented and evaluated by assessing the structural and catalytic properties as well as sequence identities and expression patterns. This review summarizes the recent development in metagenomics based approaches for identifying and exploring novel cellulases which open new avenues for their successful application in biorefineries.

Disruption of non-anchored cell wall protein NCW-1 promotes cellulase production by increasing cellobiose uptake in Neurospora crassa.

PubMed

Lin, Liangcai; Chen, Yong; Li, Jingen; Wang, Shanshan; Sun, Wenliang; Tian, Chaoguang

2017-04-01

To elucidate the mechanism of cellulase signal transduction in filamentous fungi including the components of the cellulase induction pathway. Neurospora crassa ncw-1 encodes a non-anchored cell wall protein. The absence of ncw-1 increased cellulase gene expression and this is not due to relieving carbon catabolite repression mediated by the cre-1 pathway. A mutant lacking genes encoding both three major β-glucosidase enzymes and NCW-1 (Δ3βGΔncw-1) was constructed. Transcriptome analysis of the quadruple mutant demonstrated enhanced expression of cellodextrin transporters after ncw-1 deletion, indicating that ncw-1 affects cellulase expression and production by inhibiting the uptake of the cellodextrin. NCW-1 is a novel component that plays a critical role in the cellulase induction signaling pathway.

Synergetic effect of yeast cell-surface expression of cellulase and expansin-like protein on direct ethanol production from cellulose

PubMed Central

2013-01-01

Background Numerous studies have examined the direct fermentation of cellulosic materials by cellulase-expressing yeast; however, ethanol productivity in these systems has not yet reached an industrial level. Certain microorganisms, such as the cellulolytic fungus Trichoderma reesei, produce expansin-like proteins, which have a cellulose-loosening effect that may increase the breakdown of cellulose. Here, to improve the direct conversion of cellulose to ethanol, yeast Saccharomyces cerevisiae co-displaying cellulase and expansin-like protein on the cell surface were constructed and examined for direct ethanol fermentation performance. Results The cellulase and expansin-like protein co-expressing strain showed 246 mU/g-wet cell of phosphoric acid swollen cellulose (PASC) degradation activity, which corresponded to 2.9-fold higher activity than that of a cellulase-expressing strain. This result clearly demonstrated that yeast cell-surface expressed cellulase and expansin-like protein act synergistically to breakdown cellulose. In fermentation experiments examining direct ethanol production from PASC, the cellulase and expansin-like protein co-expressing strain produced 3.4 g/L ethanol after 96 h of fermentation, a concentration that was 1.4-fold higher than that achieved by the cellulase-expressing strain (2.5 g/L). Conclusions The PASC degradation and fermentation ability of an engineered yeast strain was markedly improved by co-expressing cellulase and expansin-like protein on the cell surface. To our knowledge, this is the first report to demonstrate the synergetic effect of co-expressing cellulase and expansin-like protein on a yeast cell surface, which may be a promising strategy for constructing direct ethanol fermenting yeast from cellulose. PMID:23835302

Differential Involvement of β-Glucosidases from Hypocrea jecorina in Rapid Induction of Cellulase Genes by Cellulose and Cellobiose

PubMed Central

Zhou, Qingxin; Xu, Jintao; Kou, Yanbo; Lv, Xinxing; Zhang, Xi; Zhao, Guolei; Zhang, Weixin; Chen, Guanjun

2012-01-01

Appropriate perception of cellulose outside the cell by transforming it into an intracellular signal ensures the rapid production of cellulases by cellulolytic Hypocrea jecorina. The major extracellular β-glucosidase BglI (CEL3a) has been shown to contribute to the efficient induction of cellulase genes. Multiple β-glucosidases belonging to glycosyl hydrolase (GH) family 3 and 1, however, exist in H. jecorina. Here we demonstrated that CEL1b, like CEL1a, was an intracellular β-glucosidase displaying in vitro transglycosylation activity. We then found evidence that these two major intracellular β-glucosidases were involved in the rapid induction of cellulase genes by insoluble cellulose. Deletion of cel1a and cel1b significantly compromised the efficient gene expression of the major cellulase gene, cbh1. Simultaneous absence of BglI, CEL1a, and CEL1b caused the induction of the cellulase gene by cellulose to further deteriorate. The induction defect, however, was not observed with cellobiose. The absence of the three β-glucosidases, rather, facilitated the induced synthesis of cellulase on cellobiose. Furthermore, addition of cellobiose restored the productive induction on cellulose in the deletion strains. The results indicate that the three β-glucosidases may not participate in transforming cellobiose beyond hydrolysis to provoke cellulase formation in H. jecorina. They may otherwise contribute to the accumulation of cellobiose from cellulose as inducing signals. PMID:23002106

One-step process of hydrothermal and alkaline treatment of wheat straw for improving the enzymatic saccharification.

PubMed

Sun, Shaolong; Zhang, Lidan; Liu, Fang; Fan, Xiaolin; Sun, Run-Cang

2018-01-01

To increase the production of bioethanol, a two-step process based on hydrothermal and dilute alkaline treatment was applied to reduce the natural resistance of biomass. However, the process required a large amount of water and a long operation time due to the solid/liquid separation before the alkaline treatment, which led to decrease the pure economic profit for production of bioethanol. Therefore, four one-step processes based on order of hydrothermal and alkaline treatment have been developed to enhance concentration of glucose of wheat straw by enzymatic saccharification. The aim of the present study was to systematically evaluated effect for different one-step processes by analyzing the physicochemical properties (composition, structural change, crystallinity, surface morphology, and BET surface area) and enzymatic saccharification of the treated substrates. In this study, hemicelluloses and lignins were removed from wheat straw and the morphologic structures were destroyed to various extents during the four one-step processes, which were favorable for cellulase absorption on cellulose. A positive correlation was also observed between the crystallinity and enzymatic saccharification rate of the substrate under the conditions given. The surface area of the substrate was positively related to the concentration of glucose in this study. As compared to the control (3.0 g/L) and treated substrates (11.2-14.6 g/L) obtained by the other three one-step processes, the substrate treated by one-step process based on successively hydrothermal and alkaline treatment had a maximum glucose concentration of 18.6 g/L, which was due to the high cellulose concentration and surface area for the substrate, accompanying with removal of large amounts of lignins and hemicelluloses. The present study demonstrated that the order of hydrothermal and alkaline treatment had significant effects on the physicochemical properties and enzymatic saccharification of wheat straw. The one

Acetylation of loofa (Luffa cylindrica) sponge as immobilization carrier for bioprocesses involving cellulase.

PubMed

Hideno, Akihiro; Ogbonna, James C; Aoyagi, Hideki; Tanaka, Hideo

2007-04-01

The feasibility of using loofa sponge for immobilization of cellulase-producing microorganisms was investigated by acetylating loofa sponge. Acetylation was achieved by autoclaving process of loofa sponge immersed in acetic anhydride at various temperatures for various times. The degree of acetylation, as inferred by the weight percentage gain (WPG), was enhanced by increasing both temperature and the duration of acetylation. The acetylation of a piece of loofa sponge in an autoclave at 120 degrees C for 20 min resulted in a WPG of about 8%, which was sufficient to protect the loofa sponge against cellulose degradation. The acetylated loofa sponge prepared under this condition was not decomposed by commercial cellulase and its structure was maintained for more than 720 h during repeated-batch treatments with commercial cellulase. A flocculating yeast (Saccharomyces cerevisiae IR-2) and a fungus (Trichoderma reesei QM9414) were successfully immobilized in the acetylated loofa sponge. In each case, the percentage of immobilized cells was as high as that obtained using nonacetylated loofa sponge. Acetylation had no adverse effects on cell growth and immobilization of T. reesei QM9414, as well as on cell growth and ethanol production by S. cerevisiae IR-2. T. reesei QM9414 immobilized on an acetylated loofa sponge was successfully used for repeated-batch cellulase production from commercial cellulose powder. Although the acetylated loofa sponge showed a slight weight loss, it was not disintegrated by activated sludge. The results obtained in this study showed that acetylated loofa sponge is suitable as an immobilization carrier for bioprocesses involving cellulase.

In vitro flow cytometry-based screening platform for cellulase engineering

PubMed Central

Körfer, Georgette; Pitzler, Christian; Vojcic, Ljubica; Martinez, Ronny; Schwaneberg, Ulrich

2016-01-01

Ultrahigh throughput screening (uHTS) plays an essential role in directed evolution for tailoring biocatalysts for industrial applications. Flow cytometry-based uHTS provides an efficient coverage of the generated protein sequence space by analysis of up to 107 events per hour. Cell-free enzyme production overcomes the challenge of diversity loss during the transformation of mutant libraries into expression hosts, enables directed evolution of toxic enzymes, and holds the promise to efficiently design enzymes of human or animal origin. The developed uHTS cell-free compartmentalization platform (InVitroFlow) is the first report in which a flow cytometry-based screened system has been combined with compartmentalized cell-free expression for directed cellulase enzyme evolution. InVitroFlow was validated by screening of a random cellulase mutant library employing a novel screening system (based on the substrate fluorescein-di-β-D-cellobioside), and yielded significantly improved cellulase variants (e.g. CelA2-H288F-M1 (N273D/H288F/N468S) with 13.3-fold increased specific activity (220.60 U/mg) compared to CelA2 wildtype: 16.57 U/mg). PMID:27184298

The Multi Domain Caldicellulosiruptor bescii CelA Cellulase Excels at the Hydrolysis of Crystalline Cellulose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brunecky, Roman; Donohoe, Bryon S.; Yarbrough, John M.

The crystalline nature of cellulose microfibrils is one of the key factors influencing biomass recalcitrance which is a key technical and economic barrier to overcome to make cellulosic biofuels a commercial reality. To date, all known fungal enzymes tested have great difficulty degrading highly crystalline cellulosic substrates. We have demonstrated that the CelA cellulase from Caldicellulosiruptor bescii degrades highly crystalline cellulose as well as low crystallinity substrates making it the only known cellulase to function well on highly crystalline cellulose. Unlike the secretomes of cellulolytic fungi, which typically comprise multiple, single catalytic domain enzymes for biomass degradation, some bacterial systemsmore » employ an alternative strategy that utilizes multi-catalytic domain cellulases. Additionally, CelA is extremely thermostable and highly active at elevated temperatures, unlike commercial fungal cellulases. Furthermore we have determined that the factors negatively affecting digestion of lignocellulosic materials by C. bescii enzyme cocktails containing CelA appear to be significantly different from the performance barriers affecting fungal cellulases. Furthermore, we explore the activity and degradation mechanism of CelA on a variety of pretreated substrates to better understand how the different bulk components of biomass, such as xylan and lignin, impact its performance.« less

The Multi Domain Caldicellulosiruptor bescii CelA Cellulase Excels at the Hydrolysis of Crystalline Cellulose

DOE PAGES

Brunecky, Roman; Donohoe, Bryon S.; Yarbrough, John M.; ...

2017-08-29

The crystalline nature of cellulose microfibrils is one of the key factors influencing biomass recalcitrance which is a key technical and economic barrier to overcome to make cellulosic biofuels a commercial reality. To date, all known fungal enzymes tested have great difficulty degrading highly crystalline cellulosic substrates. We have demonstrated that the CelA cellulase from Caldicellulosiruptor bescii degrades highly crystalline cellulose as well as low crystallinity substrates making it the only known cellulase to function well on highly crystalline cellulose. Unlike the secretomes of cellulolytic fungi, which typically comprise multiple, single catalytic domain enzymes for biomass degradation, some bacterial systemsmore » employ an alternative strategy that utilizes multi-catalytic domain cellulases. Additionally, CelA is extremely thermostable and highly active at elevated temperatures, unlike commercial fungal cellulases. Furthermore we have determined that the factors negatively affecting digestion of lignocellulosic materials by C. bescii enzyme cocktails containing CelA appear to be significantly different from the performance barriers affecting fungal cellulases. Furthermore, we explore the activity and degradation mechanism of CelA on a variety of pretreated substrates to better understand how the different bulk components of biomass, such as xylan and lignin, impact its performance.« less

40 CFR 23.7 - Timing of Administrator's action under Safe Drinking Water Act.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Safe Drinking Water Act. 23.7 Section 23.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL JUDICIAL REVIEW UNDER EPA-ADMINISTERED STATUTES § 23.7 Timing of Administrator's action under Safe Drinking Water Act. Unless the Administrator otherwise explicitly provides in a particular promulgation...

40 CFR 23.7 - Timing of Administrator's action under Safe Drinking Water Act.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Safe Drinking Water Act. 23.7 Section 23.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL JUDICIAL REVIEW UNDER EPA-ADMINISTERED STATUTES § 23.7 Timing of Administrator's action under Safe Drinking Water Act. Unless the Administrator otherwise explicitly provides in a particular promulgation...

Mineral Carbonation Potential of CO2 from Natural and Industrial-based Alkalinity Sources

NASA Astrophysics Data System (ADS)

Wilcox, J.; Kirchofer, A.

2014-12-01

of 85%. The total CO2 storage potential for the alkalinity sources considered in the U.S. ranges from 1.3% to 23.7% of U.S. CO2 emissions, depending on the assumed availability of natural alkalinity sources and efficiency of the mineral carbonation processes.

Enhanced cellulase recovery without β-glucosidase supplementation for cellulosic ethanol production using an engineered strain and surfactant.

PubMed

Huang, Renliang; Guo, Hong; Su, Rongxin; Qi, Wei; He, Zhimin

2017-03-01

Recycling cellulases by substrate adsorption is a promising strategy for reducing the enzyme cost of cellulosic ethanol production. However, β-glucosidase has no carbohydrate-binding module (CBM). Thus, additional enzymes are required in each cycle to achieve a high ethanol yield. In this study, we report a new method of recycling cellulases without β-glucosidase supplementation using lignocellulosic substrate, an engineered strain expressing β-glucosidase and Tween 80. The cellulases and Tween 80 were added to an aqueous suspension of diluted sulfuric acid/ammonia-treated corncobs in a simultaneous saccharification and fermentation (SSF) process for ethanol production. Subsequently, the addition of fresh pretreated corncobs to the fermentation liquor and remaining solid residue provided substrates with absorbed cellulases for the next SSF cycle. This method provided excellent ethanol production in three successive SSF cycles without requiring the addition of new cellulases. For a 10% (w/v) solid loading, a cellulase dosage of 30 filter paper units (FPU)/g cellulose, 0.5% Tween 80, and 2 g/L of the engineered strain, approximately 90% of the initial ethanol concentration from the first SSF process was obtained in the next two SSF processes, with a total ethanol production of 306.27 g/kg corncobs and an enzyme productivity of 0.044 g/FPU. Tween 80 played an important role in enhancing cellulase recovery. This new enzyme recycling method is more efficient and practical than other reported methods. Biotechnol. Bioeng. 2017;114: 543-551. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Thermophilic Bacillus coagulans requires less cellulases for simultaneous saccharification and fermentation of cellulose to products than mesophilic microbial biocatalysts.

PubMed

Ou, Mark S; Mohammed, Nazimuddin; Ingram, L O; Shanmugam, K T

2009-05-01

Ethanol production from lignocellulosic biomass depends on simultaneous saccharification of cellulose to glucose by fungal cellulases and fermentation of glucose to ethanol by microbial biocatalysts (SSF). The cost of cellulase enzymes represents a significant challenge for the commercial conversion of lignocellulosic biomass into renewable chemicals such as ethanol and monomers for plastics. The cellulase concentration for optimum SSF of crystalline cellulose with fungal enzymes and a moderate thermophile, Bacillus coagulans, was determined to be about 7.5 FPU g(-1) cellulose. This is about three times lower than the amount of cellulase required for SSF with Saccharomyces cerevisiae, Zymomonas mobilis, or Lactococcus lactis subsp. lactis whose growth and fermentation temperature optimum is significantly lower than that of the fungal cellulase activity. In addition, B. coagulans also converted about 80% of the theoretical yield of products from 40 g/L of crystalline cellulose in about 48 h of SSF with 10 FPU g(-1) cellulose while yeast, during the same period, only produced about 50% of the highest yield produced at end of 7 days of SSF. These results show that a match in the temperature optima for cellulase activity and fermentation is essential for decreasing the cost of cellulase in cellulosic ethanol production.

48 CFR 252.237-7010 - Prohibition on interrogation of detainees by contractor personnel.

Code of Federal Regulations, 2014 CFR

2014-10-01

... interrogation of detainees by contractor personnel. 252.237-7010 Section 252.237-7010 Federal Acquisition... interrogation of detainees by contractor personnel. As prescribed in 237.173-5, use the following clause: Prohibition on Interrogation of Detainees by Contractor Personnel ((JUN 2013)) (a) Definitions. As used in...

48 CFR 252.237-7010 - Prohibition on interrogation of detainees by contractor personnel.

Code of Federal Regulations, 2012 CFR

2012-10-01

... interrogation of detainees by contractor personnel. 252.237-7010 Section 252.237-7010 Federal Acquisition... interrogation of detainees by contractor personnel. As prescribed in 237.173-5, use the following clause: Prohibition on Interrogation of Detainees by Contractor Personnel (NOV 2010) (a) Definitions. As used in this...

48 CFR 252.237-7010 - Prohibition on interrogation of detainees by contractor personnel.

Code of Federal Regulations, 2013 CFR

2013-10-01

... interrogation of detainees by contractor personnel. 252.237-7010 Section 252.237-7010 Federal Acquisition... interrogation of detainees by contractor personnel. As prescribed in 237.173-5, use the following clause: Prohibition on Interrogation of Detainees by Contractor Personnel ((JUN 2013)) (a) Definitions. As used in...

48 CFR 252.237-7010 - Prohibition on interrogation of detainees by contractor personnel.

Code of Federal Regulations, 2011 CFR

2011-10-01

... interrogation of detainees by contractor personnel. 252.237-7010 Section 252.237-7010 Federal Acquisition... interrogation of detainees by contractor personnel. As prescribed in 237.173-5, use the following clause: PROHIBITION ON INTERROGATION OF DETAINEES BY CONTRACTOR PERSONNEL (NOV 2010) (a) Definitions. As used in this...

Application of Molecular Imprinted Magnetic Fe3O4@SiO2 Nanoparticles for Selective Immobilization of Cellulase.

PubMed

Tao, Qing-Lan; Li, Yue; Shi, Ying; Liu, Rui-Jiang; Zhang, Ye-Wang; Guo, Jianyong

2016-06-01

Magnetic Fe3O4@SiO2 nanoparticles were prepared with molecular imprinting method using cellulase as the template. And the surface of the nanoparticles was chemically modified with arginine. The prepared nanoparticles were used as support for specific immobilization of cellulase. SDS-PAGE results indicated that the adsorption of cellulase onto the modified imprinted nanoparticles was selective. The immobilization yield and efficiency were obtained more than 70% after the optimization. Characterization of the immobilized cellulase revealed that the immobilization didn't change the optimal pH and temperature. The half-life of the immobilized cellulase was 2-fold higher than that of the free enzyme at 50 degrees C. After 7 cycles reusing, the immobilized enzyme still retained 77% of the original activity. These results suggest that the prepared imprinted nanoparticles have the potential industrial applications for the purification or immobilization of enzymes.

The unique GH5 cellulase member in the extreme halotolerant fungus Aspergillus glaucus CCHA is an endoglucanase with multiple tolerance to salt, alkali and heat: prospects for straw degradation applications.

PubMed

Li, Zhengqun; Pei, Xue; Zhang, Ziyu; Wei, Yi; Song, Yanyue; Chen, Lina; Liu, Shouan; Zhang, Shi-Hong

2018-07-01

In a halotolerant fungus Aspergillus glaucus CCHA, several functional proteins with stress-tolerant activity have been studied, but no secretory enzymes have been identified yet. The unique GH5 cellulase candidate from A. glaucus, an endoglucanase termed as AgCMCase, was cloned, expressed in the Pichia pastoris system and the purified enzyme was characterized. A large amount of recombinant enzyme secreted by the P. pastoris GS115 strain was purified to homogeneity. The molecular weight of the purified endoglucanase is about 55.0 kDa. The AgCMCase exhibited optimum catalytic activity at pH 5.0 and 55 °C. However, it remained relatively stable at temperatures ranging from 45 to 80 °C and pH ranging from 4.0 to 9.0. In addition, it showed higher activity at extreme NaCl concentrations from 1.0 to 4.0 M, suggesting it is an enzyme highly stable under heat, acid, alkaline and saline conditions. To evaluate the catalytic activity of AgCMCase, the hydrolysis products of rice and corn straws were successfully studied. In conclusion, the AgCMCase is a thermostable and salt-tolerant cellulase with potential for industrial application.

48 CFR 552.237-72 - Prohibition Regarding “Quasi-Military Armed Forces.”

Code of Federal Regulations, 2010 CFR

2010-10-01

...Quasi-Military Armed Forces.â 552.237-72 Section 552.237-72 Federal Acquisition Regulations System... Provisions and Clauses 552.237-72 Prohibition Regarding “Quasi-Military Armed Forces.” As prescribed in 537.110(b), insert the following clause: Prohibition Regarding “Quasi-Military Armed Forces” (SEP 1999...

48 CFR 1352.237-70 - Security processing requirements-high or moderate risk contracts.

Code of Federal Regulations, 2011 CFR

2011-10-01

... requirements-high or moderate risk contracts. 1352.237-70 Section 1352.237-70 Federal Acquisition Regulations... Provisions and Clauses 1352.237-70 Security processing requirements—high or moderate risk contracts. As prescribed in 48 CFR 1337.110-70 (b), insert the following clause: Security Processing Requirements—High or...

Characterization of the newly isolated Geobacillus sp. T1, the efficient cellulase-producer on untreated barley and wheat straws.

PubMed

Assareh, Reza; Shahbani Zahiri, Hossein; Akbari Noghabi, Kambiz; Aminzadeh, Saeed; Bakhshi Khaniki, Gholamreza

2012-09-01

A thermophile cellulase-producing bacterium was isolated and identified as closely related to Geobacillus subterraneus. The strain, named Geobacillus sp. T1, was able to grow and produce cellulase on cellobiose, microcrystalline cellulose, carboxymethylcellulose (CMC), barley straw, wheat straw and Whatman No. 1 filter paper. However, barley and wheat straws were significantly better substrates for cellulase production. When Geobacillus sp. T1 was cultivated in the presence of 0.5% barley straw, 0.1% Tween 80 and pH 6.5 at 50°C, the maximum level of free cellulase up to 143.50 U/mL was produced after 24h. This cellulase (≈ 54 kDa) was most active at pH 6.5 and 70°C. The enzyme in citrate phosphate buffer (10mM) was stable at 60°C for at least 1h. Geobacillus sp. T1 with efficient growth and cellulase production on straws seems a potential candidate for conversion of agricultural biomass to fuels. Copyright © 2012 Elsevier Ltd. All rights reserved.

Enhancement of β-xylosidase productivity in cellulase producing fungus Acremonium cellulolyticus

PubMed Central

2011-01-01

Enzymatic hydrolysis is one of the most important processes in bioethanol production from lignocellulosic biomass. Acremonium cellulolyticus is a filamentous fungus with high cellulase production but productivity of hemicellulase, especially β-xylosidase, is lower than other filamentous fungi. We identified 2.4 Kb β-xylosidase gene in the A. cellulolyticus genome sequence information and it encoded 798 amino acids without introns. To enhance hemicellulase productivity in A. cellulolyticus, we transformed this fungus with the identified β-xylosidase gene driven by the cellobiohydrolase Ι (cbh1) promoter, using the protoplast-polyethyleneglycol (PEG) method, and obtained a transformant, YKX1. Hydrolysis rate of xylooligosaccharides was more than 50-fold higher using culture supernatant from YKX1 than that from the parental strain, Y-94. Total cellulase activity (measured by filter paper assay) in YKX1 was not affected by the cbh1 promoter used for expression of β-xylosidase, and induced by cellulose. Since YKX1 can produce larger amount of β-xylosidase without affecting cellulase productivity, it is considered to be beneficial for practical monosaccharide recoveries from lignocellulosic biomass. PMID:21906369

Enhancement of β-xylosidase productivity in cellulase producing fungus Acremonium cellulolyticus.

PubMed

Kanna, Machi; Yano, Shinichi; Inoue, Hiroyuki; Fujii, Tatsuya; Sawayama, Shigeki

2011-06-30

Enzymatic hydrolysis is one of the most important processes in bioethanol production from lignocellulosic biomass. Acremonium cellulolyticus is a filamentous fungus with high cellulase production but productivity of hemicellulase, especially β-xylosidase, is lower than other filamentous fungi. We identified 2.4 Kb β-xylosidase gene in the A. cellulolyticus genome sequence information and it encoded 798 amino acids without introns. To enhance hemicellulase productivity in A. cellulolyticus, we transformed this fungus with the identified β-xylosidase gene driven by the cellobiohydrolase Ι (cbh1) promoter, using the protoplast-polyethyleneglycol (PEG) method, and obtained a transformant, YKX1. Hydrolysis rate of xylooligosaccharides was more than 50-fold higher using culture supernatant from YKX1 than that from the parental strain, Y-94. Total cellulase activity (measured by filter paper assay) in YKX1 was not affected by the cbh1 promoter used for expression of β-xylosidase, and induced by cellulose. Since YKX1 can produce larger amount of β-xylosidase without affecting cellulase productivity, it is considered to be beneficial for practical monosaccharide recoveries from lignocellulosic biomass.

Prospecting Agro-waste Cocktail: Supplementation for Cellulase Production by a Newly Isolated Thermophilic B. licheniformis 2D55.

PubMed

Kazeem, Muinat Olanike; Shah, Umi Kalsom Md; Baharuddin, Azhari Samsu; AbdulRahman, Nor' Aini

2017-08-01

Bacteria isolated from thermophilic environment that can produce cellulase as well as utilise agro-waste biomass have a high potential for developing thermostable cellulase required in the biofuel industry. The cost for cellulase represents a significant challenge in converting lignocellulose to fermentable sugars for biofuel production. Among three potential bacteria examined, Bacillus licheniformis 2D55 (accession no. KT799651) was found to produce the highest cellulolytic activity (CMCase 0.33 U/mL and FPase 0.09 U/mL) at 18-24 h fermentation when grown on microcrystalline cellulose (MCC) as a carbon source in shake flask at 50 °C. Cellulase production process was further conducted on the untreated and NaOH pretreated rice straw (RS), rice husk (RH), sugarcane bagasse (BAG) and empty fruit bunch (EFB). Untreated BAG produced the highest FPase (0.160 U/mL), while the highest CMCase (0.150 U/mL) was supported on the pretreated RH. The mixture of untreated BAG and pretreated RH as agro-waste cocktail has remarkably improved CMCase (3.7- and 1.4-fold) and FPase (2.5- and 11.5-fold) compared to the untreated BAG and pretreated RH, respectively. The mechanism of cellulase production explored through SEM analysis and the location of cellulase enzymes of the isolate was also presented. Agro-waste cocktail supplementation provides an alternative method for an efficient production of cellulase.

TTI-237: a novel microtubule-active compound with in vivo antitumor activity.

PubMed

Beyer, Carl F; Zhang, Nan; Hernandez, Richard; Vitale, Danielle; Lucas, Judy; Nguyen, Thai; Discafani, Carolyn; Ayral-Kaloustian, Semiramis; Gibbons, James J

2008-04-01

5-Chloro-6-[2,6-difluoro-4-[3-(methylamino)propoxy]phenyl]-N-[(1S)-2,2,2-trifluoro-1-methylethyl]-[1,2,4]triazolo[1,5-a]pyrimidin-7-amine butanedioate (TTI-237) is a microtubule-active compound of novel structure and function. Structurally, it is one of a class of compounds, triazolo[1,5a]pyrimidines, previously not known to bind to tubulin. Functionally, TTI-237 inhibited the binding of [(3)H]vinblastine to tubulin, but it caused a marked increase in turbidity development that more closely resembled the effect observed with docetaxel than that observed with vincristine. The morphologic character of the presumptive polymer is unknown at present. When applied to cultured human tumor cells at concentrations near its IC(50) value for cytotoxicity (34 nmol/L), TTI-237 induced multiple spindle poles and multinuclear cells, as did paclitaxel, but not vincristine or colchicine. Flow cytometry experiments revealed that, at low concentrations (20-40 nmol/L), TTI-237 produced sub-G(1) nuclei and, at concentrations above 50 nmol/L, it caused a strong G(2)-M block. The compound was a weak substrate of multidrug resistance 1 (multidrug resistance transporter or P-glycoprotein). In a cell line expressing a high level of P-glycoprotein, the IC(50) of TTI-237 increased 25-fold whereas those of paclitaxel and vincristine increased 806-fold and 925-fold, respectively. TTI-237 was not recognized by the MRP or MXR transporters. TTI-237 was active in vivo in several nude mouse xenograft models of human cancer, including LoVo human colon carcinoma and U87-MG human glioblastoma, when dosed i.v. or p.o. Thus, TTI-237 has a set of properties that distinguish it from other classes of microtubule-active compounds.

7 CFR 1280.237 - Rules and Regulations.

Code of Federal Regulations, 2010 CFR

2010-01-01

... AGREEMENTS AND ORDERS; MISCELLANEOUS COMMODITIES), DEPARTMENT OF AGRICULTURE LAMB PROMOTION, RESEARCH, AND INFORMATION ORDER Lamb Promotion, Research, and Information Order Miscellaneous § 1280.237 Rules and...

40 CFR 23.7 - Timing of Administrator's action under Safe Drinking Water Act.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Timing of Administrator's action under Safe Drinking Water Act. 23.7 Section 23.7 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL JUDICIAL REVIEW UNDER EPA-ADMINISTERED STATUTES § 23.7 Timing of Administrator's action under Safe Drinking Water Act. Unless the...

48 CFR 237.7204 - Format and clauses for educational service agreements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... educational service agreements. 237.7204 Section 237.7204 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING... practices and procedures for other students of similar accomplishment in that department or field. The...

48 CFR 237.7204 - Format and clauses for educational service agreements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... educational service agreements. 237.7204 Section 237.7204 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING... practices and procedures for other students of similar accomplishment in that department or field. The...

48 CFR 237.7204 - Format and clauses for educational service agreements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... educational service agreements. 237.7204 Section 237.7204 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING... practices and procedures for other students of similar accomplishment in that department or field. The...

48 CFR 237.7204 - Format and clauses for educational service agreements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... educational service agreements. 237.7204 Section 237.7204 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING... practices and procedures for other students of similar accomplishment in that department or field. The...

Optimization of cellulase production by Penicillium sp.

PubMed

Prasanna, H N; Ramanjaneyulu, G; Rajasekhar Reddy, B

2016-12-01

The production of cellulolytic enzymes (β-exoglucanase, β-endoglucanase and β-glucosidase) by Penicillium sp. on three different media in liquid shake culture conditions was compared. The organism exhibited relatively highest activity of endoglucanase among three enzymes measured at 7-day interval during the course of its growth on Czapek-Dox medium supplemented with 0.5 % (w/v) cellulose. Cellulose at 0.5 %, lactose at 0.5 %, sawdust at 0.5 %, yeast extract at 0.2 % as a nitrogen source, pH 5.0 and 30 °C temperature were found to be optimal for growth and cellulase production by Penicillium sp. Yields of Fpase, CMCase and β-glucosidase, attained on optimized medium with Penicillium sp. were 8.7, 25 and 9.52 U/ml, respectively with increment of 9.2, 5.9 and 43.8-folds over titers of the respective enzyme on unoptimised medium. Cellulase of the fungal culture with the ratio of β-glucosidase to Fpase greater than one will hold potential for biotechnological applications.

48 CFR 1552.237-74 - Publicity.

Code of Federal Regulations, 2011 CFR

2011-10-01

... Section 1552.237-74 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY CLAUSES AND... removal or remedial activities under the Comprehensive Environmental Response, Compensation and Liability... on-scene coordinator (or Project Officer) prior to releasing any information to the news media...

48 CFR 1552.237-74 - Publicity.

Code of Federal Regulations, 2012 CFR

2012-10-01

... Section 1552.237-74 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY CLAUSES AND... removal or remedial activities under the Comprehensive Environmental Response, Compensation and Liability... on-scene coordinator (or Project Officer) prior to releasing any information to the news media...

48 CFR 1552.237-74 - Publicity.

Code of Federal Regulations, 2014 CFR

2014-10-01

... Section 1552.237-74 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY CLAUSES AND... removal or remedial activities under the Comprehensive Environmental Response, Compensation and Liability... any information to the news media regarding the removal or remedial activities being conducted under...

48 CFR 1552.237-74 - Publicity.

Code of Federal Regulations, 2010 CFR

2010-10-01

... Section 1552.237-74 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY CLAUSES AND... removal or remedial activities under the Comprehensive Environmental Response, Compensation and Liability... on-scene coordinator (or Project Officer) prior to releasing any information to the news media...

48 CFR 1552.237-74 - Publicity.

Code of Federal Regulations, 2013 CFR

2013-10-01

... Section 1552.237-74 Federal Acquisition Regulations System ENVIRONMENTAL PROTECTION AGENCY CLAUSES AND... removal or remedial activities under the Comprehensive Environmental Response, Compensation and Liability... any information to the news media regarding the removal or remedial activities being conducted under...

A β-glucosidase hyper-production Trichoderma reesei mutant reveals a potential role of cel3D in cellulase production.

PubMed

Li, Chengcheng; Lin, Fengming; Li, Yizhen; Wei, Wei; Wang, Hongyin; Qin, Lei; Zhou, Zhihua; Li, Bingzhi; Wu, Fugen; Chen, Zhan

2016-09-01

The conversion of cellulose by cellulase to fermentable sugars for biomass-based products such as cellulosic biofuels, biobased fine chemicals and medicines is an environment-friendly and sustainable process, making wastes profitable and bringing economic benefits. Trichoderma reesei is the well-known major workhorse for cellulase production in industry, but the low β-glucosidase activity in T. reesei cellulase leads to inefficiency in biomass degradation and limits its industrial application. Thus, there are ongoing interests in research to develop methods to overcome this insufficiency. Moreover, although β-glucosidases have been demonstrated to influence cellulase production and participate in the regulation of cellulase production, the underlying mechanism remains unclear. The T. reesei recombinant strain TRB1 was constructed from T. reesei RUT-C30 by the T-DNA-based mutagenesis. Compared to RUT-C30, TRB1 displays a significant enhancement of extracellular β-glucosidase (BGL1) activity with 17-fold increase, a moderate increase of both the endoglucanase (EG) activity and the exoglucanase (CBH) activity, a minor improvement of the total filter paper activity, and a faster cellulase induction. This superiority of TRB1 over RUT-C30 is independent on carbon sources and improves the saccharification ability of TRB1 cellulase on pretreated corn stover. Furthermore, TRB1 shows better resistance to carbon catabolite repression than RUT-C30. Secretome characterization of TRB1 shows that the amount of CBH, EG and BGL in the supernatant of T. reesei TRB1 was indeed increased along with the enhanced activities of these three enzymes. Surprisingly, qRT-PCR and gene cloning showed that in TRB1 β-glucosidase cel3D was mutated through the random insertion by AMT and was not expressed. The T. reesei recombinant strain TRB1 constructed in this study is more desirable for industrial application than the parental strain RUT-C30, showing extracellular β-glucosidase hyper

48 CFR 237.7002 - Area of performance and distribution of contracts.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Area of performance and distribution of contracts. 237.7002 Section 237.7002 Federal Acquisition Regulations System DEFENSE ACQUISITION REGULATIONS SYSTEM, DEPARTMENT OF DEFENSE SPECIAL CATEGORIES OF CONTRACTING SERVICE CONTRACTING Mortuary...

50 CFR 648.237 - Framework provisions.

Code of Federal Regulations, 2011 CFR

2011-10-01

..., Sept. 29, 2011. (a) Within season management action. The Councils may, at any time, initiate action to....237 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE FISHERIES OF THE NORTHEASTERN UNITED STATES Management Measures for the...

Evaluating leachate recirculation with cellulase addition to enhance waste biostabilisation and landfill gas production.

PubMed

Frank, R R; Davies, S; Wagland, S T; Villa, R; Trois, C; Coulon, F

2016-09-01

The effect of leachate recirculation with cellulase augmentation on municipal solid waste (MSW) biostabilisation and landfill gas production was investigated using batch bioreactors to determine the optimal conditions of moisture content, temperature and nutrients. Experimentation was thereafter scaled-up in 7L bioreactors. Three conditions were tested including (1) leachate recirculation only, (2) leachate recirculation with enzyme augmentation and (3) no leachate recirculation (control). Cumulative biogas production of the batch tests indicated that there was little difference between the leachate and control test conditions, producing on average 0.043m(3)biogaskg(-1) waste. However the addition of cellulase at 15×10(6)Utonne(-1) waste doubled the biogas production (0.074m(3)biogaskg(-1) waste). Similar trend was observed with the bioreactors. Cellulase addition also resulted in the highest COD reduction in both the waste and the leachate samples (47% and 42% COD reduction, respectively). In both cases, the quantity of biogas produced was closer to the lower value of theoretical and data-based biogas prediction indicators (0.05-0.4m(3)biogaskg(-1) waste). This was likely due to a high concentration of heavy metals present in the leachate, in particular Cr and Mn, which are known to be toxic to methanogens. The cost-benefit analysis (CBA) based on the settings of the study (cellulase concentration of 15×10(6)Utonne(-1) waste) showed that leachate bioaugmentation using cellulase is economically viable, with a net benefit of approximately €12.1million on a 5Mt mixed waste landfill. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of cellulase-nanoconjugates with enhanced ionic liquid and thermal stability for in situ lignocellulose saccharification.

PubMed

Grewal, Jasneet; Ahmad, Razi; Khare, S K

2017-10-01

The present work aimed to improve catalytic efficiency of Trichoderma reesei cellulase for enhanced saccharification. The cellulase was immobilized on two nanomatrices i.e. magnetic and silica nanoparticles with immobilization efficiency of 85% and 76% respectively. The nanobioconjugates exhibited increase in V max , temperature optimum, pH and thermal stability as compared with free enzyme. These could be efficiently reused for five repeated cycles and were stable in 1-ethyl-3-methylimidazoliumacetate [EMIM][Ac], an ionic liquid. Ionic liquids (IL) are used as green solvents to dissolve lignocellulosic biomass and facilitate better saccharification. The cellulase immobilized on magnetic nanoparticles was used for in situ saccharification of [EMIM][Ac] pretreated sugarcane bagasse and wheat straw for two cycles. The structural deconstruction and decrease in biomass crystallinity was confirmed by SEM, XRD and FTIR. The high hydrolysis yields (∼89%) obtained in this one-pot process coupled with IL stability and recycled use of immobilized cellulase, potentiates its usefulness in biorefineries. Copyright © 2017 Elsevier Ltd. All rights reserved.

Combinatorial Screening for Transgenic Yeasts with High Cellulase Activities in Combination with a Tunable Expression System

PubMed Central

Ito, Yoichiro; Yamanishi, Mamoru; Ikeuchi, Akinori; Imamura, Chie; Matsuyama, Takashi

2015-01-01

Combinatorial screening used together with a broad library of gene expression cassettes is expected to produce a powerful tool for the optimization of the simultaneous expression of multiple enzymes. Recently, we proposed a highly tunable protein expression system that utilized multiple genome-integrated target genes to fine-tune enzyme expression in yeast cells. This tunable system included a library of expression cassettes each composed of three gene-expression control elements that in different combinations produced a wide range of protein expression levels. In this study, four gene expression cassettes with graded protein expression levels were applied to the expression of three cellulases: cellobiohydrolase 1, cellobiohydrolase 2, and endoglucanase 2. After combinatorial screening for transgenic yeasts simultaneously secreting these three cellulases, we obtained strains with higher cellulase expressions than a strain harboring three cellulase-expression constructs within one high-performance gene expression cassette. These results show that our method will be of broad use throughout the field of metabolic engineering. PMID:26692026

Covalent Immobilization of Cellulase Using Magnetic Poly(ionic liquid) Support: Improvement of the Enzyme Activity and Stability.

PubMed

Hosseini, Seyed Hassan; Hosseini, Seyedeh Ameneh; Zohreh, Nasrin; Yaghoubi, Mahshid; Pourjavadi, Ali

2018-01-31

A magnetic nanocomposite was prepared by entrapment of Fe 3 O 4 nanoparticles into the cross-linked ionic liquid/epoxy type polymer. The resulting support was used for covalent immobilization of cellulase through the reaction with epoxy groups. The ionic surface of the support improved the adsorption of enzyme, and a large amount of enzyme (106.1 mg/g) was loaded onto the support surface. The effect of the presence of ionic monomer and covalent binding of enzyme was also investigated. The structure of support was characterized by various instruments such as FT-IR, TGA, VSM, XRD, TEM, SEM, and DLS. The activity and stability of immobilized cellulase were investigated in the prepared support. The results showed that the ionic surface and covalent binding of enzyme onto the support improved the activity, thermal stability, and reusability of cellulase compared to free cellulase.

50 CFR 648.237 - Framework provisions.

Code of Federal Regulations, 2010 CFR

2010-10-01

... may, at any time, initiate action to add or adjust management measures if they find that action is... industry-funded observers or observer set-aside program; any other management measures currently included....237 Wildlife and Fisheries FISHERY CONSERVATION AND MANAGEMENT, NATIONAL OCEANIC AND ATMOSPHERIC...

Tunable Enzymatic Activity and Enhanced Stability of Cellulase Immobilized in Biohybrid Nanogels.

PubMed

Peng, Huan; Rübsam, Kristin; Jakob, Felix; Schwaneberg, Ulrich; Pich, Andrij

2016-11-14

This paper reports a facile approach for encapsulation of enzymes in nanogels. Our approach is based on the use of reactive copolymers able to get conjugated with enzyme and build 3D colloidal networks or biohybrid nanogels. In a systematic study, we address the following question: how the chemical structure of nanogel network influences the biocatalytic activity of entrapped enzyme? The developed method allows precise control of the enzyme activity and improvement of enzyme resistance against harsh store conditions, chaotropic agents, and organic solvents. The nanogels were constructed via direct chemical cross-linking of water-soluble reactive copolymers poly(N-vinylpyrrolidone-co-N-methacryloxysuccinimide) with proteins such as enhanced green fluorescent protein (EGFP) and cellulase in water-in-oil emulsion. The water-soluble reactive copolymers with controlled amount of reactive succinimide groups and narrow dispersity were synthesized via reversible addition-fragmentation chain transfer (RAFT) polymerization. Poly(ethylene glycol) bis(3-aminopropyl) and branched polyethylenimine were utilized as model cross-linkers to optimize synthesis of nanogels with different architectures in the preliminary experiments. Biofluorescent nanogels with different loading amount of EGFP and varying cross-linking densities were obtained. We demonstrate that the biocatalytic activity of cellulase-conjugated nanogels (CNG) can be elegantly tuned by control of their cross-linking degrees. Circular dichroism (CD) spectra demonstrated that the secondary structures of the immobilized cellulase were changed in the aspect of α-helix contents. The secondary structures of cellulase in highly cross-linked nanogels were strongly altered compared with loosely cross-linked nanogels. The fluorescence resonance energy transfer (FRET) based study further revealed that nanogels with lower cross-linking degree enable higher substrate transport rate, providing easier access to the active site of

Dehydrogenase GRD1 Represents a Novel Component of the Cellulase Regulon in Trichoderma reesei (Hypocrea jecorina) ▿ † §

PubMed Central

Schuster, André; Kubicek, Christian P.; Schmoll, Monika

2011-01-01

Trichoderma reesei (Hypocrea jecorina) is nowadays the most important industrial producer of cellulase and hemicellulase enzymes, which are used for pretreatment of cellulosic biomass for biofuel production. In this study, we introduce a novel component, GRD1 (glucose-ribitol dehydrogenase 1), which shows enzymatic activity on cellobiose and positively influences cellulase gene transcription, expression, and extracellular endo-1,4-β-d-glucanase activity. grd1 is differentially transcribed upon growth on cellulose and the induction of cellulase gene expression by sophorose. The transcription of grd1 is coregulated with that of cel7a (cbh1) under inducing conditions. GRD1 is further involved in carbon source utilization on several carbon sources, such as those involved in lactose and d-galactose catabolism, in several cases in a light-dependent manner. We conclude that GRD1 represents a novel enhancer of cellulase gene expression, which by coregulation with the major cellulase may act via optimization of inducing mechanisms. PMID:21602376

Enhanced cellulase production from Trichoderma reesei Rut-C30 by engineering with an artificial zinc finger protein library.

PubMed

Zhang, Fei; Bai, Fengwu; Zhao, Xinqing

2016-10-01

Trichoderma reesei Rut-C30 is a well-known cellulase producer, and improvement of its cellulase production is of great interest. An artificial zinc finger protein (AZFP) library is constructed for expression in T. reesei Rut-C30, and a mutant strain T. reesei U3 is selected based on its enhanced cellulase production. The U3 mutant shows a 55% rise in filter paper activity and 8.1-fold increased β-glucosidase activity, when compared to the native strain T. reesei Rut-C30. It is demonstrated that enhanced β-glucosidase activity was due to elevated transcription level of β-glucosidase gene in the U3 mutant. Moreover, significant elevation in transcription levels of several putative Azfp-U3 target genes is detected in the U3 mutant, including genes encoding hypothetical transcription factors and a putative glycoside hydrolase. Furthermore, U3 cellulase shows 115% higher glucose yield from pretreated corn stover, when compared to the cellulase of T. reesei Rut-C30. These results demonstrate that AZFP can be used to improve cellulase production in T. reesei Rut-C30. Our current work offers the establishment of an alternative strategy to develop fungal cell factories for improved production of high value industrial products. Copyright © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

46 CFR 108.237 - Fuel storage facilities.

Code of Federal Regulations, 2014 CFR

2014-10-01

... AND EQUIPMENT Construction and Arrangement Helicopter Facilities § 108.237 Fuel storage facilities. (a) Helicopter fuel storage tanks must be installed as far as practicable from— (1) The landing area; and (2...

7 CFR 58.237 - Condensed surge supply.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., GENERAL SPECIFICATIONS FOR APPROVED PLANTS AND STANDARDS FOR GRADES OF DAIRY PRODUCTS 1 General... Procedures § 58.237 Condensed surge supply. Surge tanks or balance tanks if used between the evaporators and...

The composition of accessory enzymes of Penicillium chrysogenum P33 revealed by secretome and synergistic effects with commercial cellulase on lignocellulose hydrolysis.

PubMed

Yang, Yi; Yang, Jinshui; Liu, Jiawen; Wang, Ruonan; Liu, Liang; Wang, Fengqin; Yuan, Hongli

2018-06-01

Herein, we report the secretome of Penicillium chrysogenum P33 under induction of lignocellulose for the first time. A total of 356 proteins were identified, including complete cellulases and numerous hemicellulases. Supplementing a commercial cellulase with increasing dosage of P33 enzyme cocktail from 1 to 5 mg/g substrate increased the release of reducing sugars from delignified corn stover by 21.4% to 106.8%. When 50% cellulase was replaced by P33 enzyme cocktail, release of reducing sugars was 78.6% higher than with cellulase alone. Meanwhile, glucan and xylan conversion was increased by 37% and 106%, respectively. P33 enzyme cocktail also enhanced commercial cellulase hydrolysis against four different delignified lignocellulosic biomass. These findings demonstrate that mixing appropriate amount of P33 cocktail with cellulase improves polysaccharide hydrolysis, suggesting P33 enzymes have great potential for industrial applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

Designing novel cellulase systems through agent-based modeling and global sensitivity analysis.

PubMed

Apte, Advait A; Senger, Ryan S; Fong, Stephen S

2014-01-01

Experimental techniques allow engineering of biological systems to modify functionality; however, there still remains a need to develop tools to prioritize targets for modification. In this study, agent-based modeling (ABM) was used to build stochastic models of complexed and non-complexed cellulose hydrolysis, including enzymatic mechanisms for endoglucanase, exoglucanase, and β-glucosidase activity. Modeling results were consistent with experimental observations of higher efficiency in complexed systems than non-complexed systems and established relationships between specific cellulolytic mechanisms and overall efficiency. Global sensitivity analysis (GSA) of model results identified key parameters for improving overall cellulose hydrolysis efficiency including: (1) the cellulase half-life, (2) the exoglucanase activity, and (3) the cellulase composition. Overall, the following parameters were found to significantly influence cellulose consumption in a consolidated bioprocess (CBP): (1) the glucose uptake rate of the culture, (2) the bacterial cell concentration, and (3) the nature of the cellulase enzyme system (complexed or non-complexed). Broadly, these results demonstrate the utility of combining modeling and sensitivity analysis to identify key parameters and/or targets for experimental improvement.

Designing novel cellulase systems through agent-based modeling and global sensitivity analysis

PubMed Central

Apte, Advait A; Senger, Ryan S; Fong, Stephen S

2014-01-01

Experimental techniques allow engineering of biological systems to modify functionality; however, there still remains a need to develop tools to prioritize targets for modification. In this study, agent-based modeling (ABM) was used to build stochastic models of complexed and non-complexed cellulose hydrolysis, including enzymatic mechanisms for endoglucanase, exoglucanase, and β-glucosidase activity. Modeling results were consistent with experimental observations of higher efficiency in complexed systems than non-complexed systems and established relationships between specific cellulolytic mechanisms and overall efficiency. Global sensitivity analysis (GSA) of model results identified key parameters for improving overall cellulose hydrolysis efficiency including: (1) the cellulase half-life, (2) the exoglucanase activity, and (3) the cellulase composition. Overall, the following parameters were found to significantly influence cellulose consumption in a consolidated bioprocess (CBP): (1) the glucose uptake rate of the culture, (2) the bacterial cell concentration, and (3) the nature of the cellulase enzyme system (complexed or non-complexed). Broadly, these results demonstrate the utility of combining modeling and sensitivity analysis to identify key parameters and/or targets for experimental improvement. PMID:24830736

Conversion of woody biomass into fermentable sugars by cellulase from Agaricus arvensis.

PubMed

Jeya, Marimuthu; Nguyen, Ngoc-Phuong-Thao; Moon, Hee-Jung; Kim, Sang-Hwan; Lee, Jung-Kul

2010-11-01

Agaricus arvensis, a newly isolated basidiomycetous fungus, was found to secrete efficient cellulases. The strain produced the highest endoglucanase (EG), cellobiohydrolase (CBH) and beta-glucosidase (BGL) activities of 0.3, 3.2 and 8U/mg-protein, respectively, with rice straw as the carbon source. Saccharification of the woody biomass with A. arvensis cellulase as the enzyme source released a high level of fermentable sugars. Enzymatic hydrolysis of the poplar biomass was optimized using the response surface methodology in order to study the influence of the variables (pH, temperature, cellulases concentration and substrate concentration). The enzyme and substrate concentrations were identified as the limiting factors for the saccharification of poplar wood biomass. A total reducing sugar level of 29g/L (293mg/g-substrate) was obtained at an enzyme concentration of 65FPU/g-substrate after optimization of the hydrolysis parameters. The model validation showed a good agreement between the experimental results and the predicted responses. A. arvensis could be a good candidate for the production of reducing sugars from a cellulosic biomass.

33 CFR 110.237 - Pacific Ocean at Waimea, Hawaii, Naval Anchorage.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., Naval Anchorage. 110.237 Section 110.237 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF..., Hawaii, Naval Anchorage. (a) The Anchorage grounds. All the waters within a circle having a radius of 300.... Except in an emergency, no vessel except a Naval vessel may anchor or moor in this anchorage without...

Regulation of cellulase expression, sporulation, and morphogenesis by velvet family proteins in Trichoderma reesei.

PubMed

Liu, Kuimei; Dong, Yanmei; Wang, Fangzhong; Jiang, Baojie; Wang, Mingyu; Fang, Xu

2016-01-01

Homologs of the velvet protein family are encoded by the ve1, vel2, and vel3 genes in Trichoderma reesei. To test their regulatory functions, the velvet protein-coding genes were disrupted, generating Δve1, Δvel2, and Δvel3 strains. The phenotypic features of these strains were examined to identify their functions in morphogenesis, sporulation, and cellulase expression. The three velvet-deficient strains produced more hyphal branches, indicating that velvet family proteins participate in the morphogenesis in T. reesei. Deletion of ve1 and vel3 did not affect biomass accumulation, while deletion of vel2 led to a significantly hampered growth when cellulose was used as the sole carbon source in the medium. The deletion of either ve1 or vel2 led to the sharp decrease of sporulation as well as a global downregulation of cellulase-coding genes. In contrast, although the expression of cellulase-coding genes of the ∆vel3 strain was downregulated in the dark, their expression in light condition was unaffected. Sporulation was hampered in the ∆vel3 strain. These results suggest that Ve1 and Vel2 play major roles, whereas Vel3 plays a minor role in sporulation, morphogenesis, and cellulase expression.

48 CFR 352.237-71 - Crime Control Act-reporting of child abuse.

Code of Federal Regulations, 2012 CFR

2012-10-01

...-reporting of child abuse. 352.237-71 Section 352.237-71 Federal Acquisition Regulations System HEALTH AND... personnel and administrators, nurses, health care practitioners, chiropractors, osteopaths, pharmacists... personnel, psychologists, psychiatrists, mental health professionals, child care workers and administrators...

48 CFR 352.237-71 - Crime Control Act-reporting of child abuse.

Code of Federal Regulations, 2014 CFR

2014-10-01

...-reporting of child abuse. 352.237-71 Section 352.237-71 Federal Acquisition Regulations System HEALTH AND... personnel and administrators, nurses, health care practitioners, chiropractors, osteopaths, pharmacists... personnel, psychologists, psychiatrists, mental health professionals, child care workers and administrators...

48 CFR 352.237-71 - Crime Control Act-reporting of child abuse.

Code of Federal Regulations, 2011 CFR

2011-10-01

...-reporting of child abuse. 352.237-71 Section 352.237-71 Federal Acquisition Regulations System HEALTH AND... personnel and administrators, nurses, health care practitioners, chiropractors, osteopaths, pharmacists... personnel, psychologists, psychiatrists, mental health professionals, child care workers and administrators...

48 CFR 352.237-71 - Crime Control Act-reporting of child abuse.

Code of Federal Regulations, 2013 CFR

2013-10-01

...-reporting of child abuse. 352.237-71 Section 352.237-71 Federal Acquisition Regulations System HEALTH AND... personnel and administrators, nurses, health care practitioners, chiropractors, osteopaths, pharmacists... personnel, psychologists, psychiatrists, mental health professionals, child care workers and administrators...

48 CFR 237.102-74 - Taxonomy for the acquisition of services.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 48 Federal Acquisition Regulations System 3 2012-10-01 2012-10-01 false Taxonomy for the... Service Contracts-General 237.102-74 Taxonomy for the acquisition of services. See PGI 237.102-74 for OUSD(AT&L) DPAP memorandum, “Taxonomy for the Acquisition of Services,” dated November 23, 2010. [75 FR...

48 CFR 237.102-74 - Taxonomy for the acquisition of services.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Taxonomy for the... Service Contracts-General 237.102-74 Taxonomy for the acquisition of services. See PGI 237.102-74 for OUSD(AT&L) DPAP memorandum, “Taxonomy for the Acquisition of Services,” dated November 23, 2010. [75 FR...

48 CFR 237.102-74 - Taxonomy for the acquisition of services.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 48 Federal Acquisition Regulations System 3 2013-10-01 2013-10-01 false Taxonomy for the... Service Contracts-General 237.102-74 Taxonomy for the acquisition of services. See PGI 237.102-74 for OUSD(AT&L) DPAP memorandum, “Taxonomy for the Acquisition of Services,” dated November 23, 2010. [75 FR...

48 CFR 252.237-7015 - Loss or damage (weight of articles).

Code of Federal Regulations, 2010 CFR

2010-10-01

... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Loss or damage (weight of... of Provisions And Clauses 252.237-7015 Loss or damage (weight of articles). As prescribed in 237.7101(d), use the following clause: Loss or Damage (Weight of Articles) (DEC 1991) (a) The Contractor...

48 CFR 252.237-7015 - Loss or damage (weight of articles).

Code of Federal Regulations, 2011 CFR

2011-10-01

... 48 Federal Acquisition Regulations System 3 2011-10-01 2011-10-01 false Loss or damage (weight of... of Provisions And Clauses 252.237-7015 Loss or damage (weight of articles). As prescribed in 237.7101(d), use the following clause: Loss or Damage (Weight of Articles) (DEC 1991) (a) The Contractor...

Disruption of Trichoderma reesei cre2, encoding an ubiquitin C-terminal hydrolase, results in increased cellulase activity

PubMed Central

2011-01-01

Background The filamentous fungus Trichoderma reesei (Hypocrea jecorina) is an important source of cellulases for use in the textile and alternative fuel industries. To fully understand the regulation of cellulase production in T. reesei, the role of a gene known to be involved in carbon regulation in Aspergillus nidulans, but unstudied in T. reesei, was investigated. Results The T. reesei orthologue of the A. nidulans creB gene, designated cre2, was identified and shown to be functional through heterologous complementation of a creB mutation in A. nidulans. A T. reesei strain was constructed using gene disruption techniques that contained a disrupted cre2 gene. This strain, JKTR2-6, exhibited phenotypes similar to the A. nidulans creB mutant strain both in carbon catabolite repressing, and in carbon catabolite derepressing conditions. Importantly, the disruption also led to elevated cellulase levels. Conclusions These results demonstrate that cre2 is involved in cellulase expression. Since the disruption of cre2 increases the amount of cellulase activity, without severe morphological affects, targeting creB orthologues for disruption in other industrially useful filamentous fungi, such as Aspergillus oryzae, Trichoderma harzianum or Aspergillus niger may also lead to elevated hydrolytic enzyme activity in these species. PMID:22070776

Kinetic and thermodynamic properties of alginate lyase and cellulase co-produced by Exiguobacterium species Alg-S5.

PubMed

Mohapatra, Bidyut R

2017-05-01

In an effort to screen out the alginolytic and cellulolytic bacteria from the putrefying invasive seaweed Sargassum species accumulated off Barbados' coast, a potent bacterial strain was isolated. This bacterium, which simultaneously produced alginate lyase and cellulase, was identified as Exiguobacterium sp. Alg-S5 via the phylogenetic approach targeting the 16S rRNA gene. The co-produced alginate lyase and cellulase exhibited maximal enzymatic activity at pH 7.5 and at 40°C and 45°C, respectively. The K m and V max values recorded as 0.91mg/mL and 21.8U/mg-protein, respectively, for alginate lyase, and 10.9mg/mL and 74.6U/mg-protein, respectively, for cellulase. First order kinetic analysis of the thermal denaturation of the co-produced alginate lyase and cellulase in the temperature range from 40°C to 55°C revealed that both the enzymes were thermodynamically efficient by displaying higher activation energy and enthalpy of denaturation. These enzymatic properties indicate the potential industrial importance of this bacterium in algal biomass conversion. This appears to be the first report on assessing the efficacy of a bacterium for the co-production of alginate lyase and cellulase. Copyright © 2017 Elsevier B.V. All rights reserved.

Kinetic study of Escherichia coli BPPTCC-EgRK2 to produce recombinant cellulase for ethanol production from oil palm empty fruit bunch

NASA Astrophysics Data System (ADS)

Limoes, S.; Rahman, S. F.; Setyahadi, S.; Gozan, M.

2018-03-01

Oil Palm Empty Fruit Bunch (OPEFB) is an abundant biomass resource in Indonesia, which contains 46,77% (w/w) of cellulose. The high cellulose content of OPEFB can be used as a substrate for bacteria cultivation to produce cellulase. By using OPEFB as an alternative substrate, the production cost of cellulase in industrial scale can be suppressed. However, currently there are no available research that simulate a cellulase production plant design. Prior to simulating the cellulase plant design, kinetic studies of bacteria used in cultivation are needed to create an accurate simulation. In this research, kinetic studies of E. coli BPPTCC-EgRK2 growth were examined with the Monod approach to get the Monod constant (Ks) and maximum specific growth rate (μmax). This study found that E. coli BPPTCC-EgRK2 have μmax and Ks of 1.581 and 0.0709 respectively. BPPTCC-EgRK2 produced intracellular cellulase, thus gave linear correlation between cell concentration and cellulase production.

Construction of cellulose-utilizing Escherichia coli based on a secretable cellulase.

PubMed

Gao, Dongfang; Luan, Yaqi; Wang, Qian; Liang, Quanfeng; Qi, Qingsheng

2015-10-09

The microbial conversion of plant biomass into value added products is an attractive option to address the impacts of petroleum dependency. The Gram-negative bacterium Escherichia coli is commonly used as host for the industrial production of various chemical products with a variety of sugars as carbon sources. However, this strain neither produces endogenous cellulose degradation enzymes nor secrets heterologous cellulases for its poor secretory capacity. Thus, a cellulolytic E. coli strain capable of growth on plant biomass would be the first step towards producing chemicals and fuels. We previously identified the catalytic domain of a cellulase (Cel-CD) and its N-terminal sequence (N20) that can serve as carriers for the efficient extracellular production of target enzymes. This finding suggested that cellulose-utilizing E. coli can be engineered with minimal heterologous enzymes. In this study, a β-glucosidase (Tfu0937) was fused to Cel-CD and its N-terminal sequence respectively to obtain E. coli strains that were able to hydrolyze the cellulose. Recombinant strains were confirmed to use the amorphous cellulose as well as cellobiose as the sole carbon source for growth. Furthermore, both strains were engineered with poly (3-hydroxybutyrate) (PHB) synthesis pathway to demonstrate the production of biodegradable polyesters directly from cellulose materials without exogenously added cellulases. The yield of PHB reached 2.57-8.23 wt% content of cell dry weight directly from amorphous cellulose/cellobiose. Moreover, we found the Cel-CD and N20 secretion system can also be used for the extracellular production of other hydrolytic enzymes. This study suggested that a cellulose-utilizing E. coli was created based on a heterologous cellulase secretion system and can be used to produce biofuels and biochemicals directly from cellulose. This system also offers a platform for conversion of other abundant renewable biomass to biofuels and biorefinery products.

Evaluation of Bacterial Expansin EXLX1 as a Cellulase Synergist for the Saccharification of Lignocellulosic Agro-Industrial Wastes

PubMed Central

Lin, Hui; Shen, Qi; Zhan, Ju-Mei; Wang, Qun; Zhao, Yu-Hua

2013-01-01

Various types of lignocellulosic wastes extensively used in biofuel production were provided to assess the potential of EXLX1 as a cellulase synergist. Enzymatic hydrolysis of natural wheat straw showed that all the treatments using mixtures of cellulase and an optimized amount of EXLX1, released greater quantities of sugars than those using cellulase alone, regardless of cellulase dosage and incubation time. EXLX1 exhibited different synergism and binding characteristics for different wastes, but this can be related to their lignocellulosic components. The cellulose proportion could be one of the important factors. However, when the cellulose proportion of different biomass samples exhibited no remarkable differences, a higher synergism of EXLX1 is prone to occur on these materials, with a high proportion of hemicellulose and a low proportion of lignin. The information could be favorable to assess whether EXLX1 is effective as a cellulase synergist for the hydrolysis of the used materials. Binding assay experiments further suggested that EXLX1 bound preferentially to alkali pretreated materials, as opposed to acid pretreated materials under the assay condition and the binding preference would be affected by incubation temperature. PMID:24086425

Occupational asthma caused by cellulase and lipase in the detergent industry.

PubMed

Brant, A; Hole, A; Cannon, J; Helm, J; Swales, C; Welch, J; Taylor, A Newman; Cullinan, P

2004-09-01

Three employees from two different detergent companies were investigated for occupational asthma, using skin prick tests, serum specific IgE, and specific bronchial challenge. Two were challenged with lipase and one with cellulase. All three cases had immunological evidence of sensitisation to the detergent enzymes with which they worked. Bronchial challenge in each provoked a reproducible dual asthmatic response, which reproduced their work related symptoms. These are the first reported cases of occupational asthma attributable to cellulase and lipase in the detergent industry. Four of the most common enzymes used in this industry have now been reported to cause occupational asthma; continued vigilance and caution are needed when working with these or other enzymes.

Ras GTPases Modulate Morphogenesis, Sporulation and Cellulase Gene Expression in the Cellulolytic Fungus Trichoderma reesei

PubMed Central

Zhang, Jiwei; Zhang, Yanmei; Zhong, Yaohua; Qu, Yinbo; Wang, Tianhong

2012-01-01

Background The model cellulolytic fungus Trichoderma reesei (teleomorph Hypocrea jecorina) is capable of responding to environmental cues to compete for nutrients in its natural saprophytic habitat despite its genome encodes fewer degradative enzymes. Efficient signalling pathways in perception and interpretation of environmental signals are indispensable in this process. Ras GTPases represent a kind of critical signal proteins involved in signal transduction and regulation of gene expression. In T. reesei the genome contains two Ras subfamily small GTPases TrRas1 and TrRas2 homologous to Ras1 and Ras2 from S. cerevisiae, but their functions remain unknown. Methodology/Principal Findings Here, we have investigated the roles of GTPases TrRas1 and TrRas2 during fungal morphogenesis and cellulase gene expression. We show that both TrRas1 and TrRas2 play important roles in some cellular processes such as polarized apical growth, hyphal branch formation, sporulation and cAMP level adjustment, while TrRas1 is more dominant in these processes. Strikingly, we find that TrRas2 is involved in modulation of cellulase gene expression. Deletion of TrRas2 results in considerably decreased transcription of cellulolytic genes upon growth on cellulose. Although the strain carrying a constitutively activated TrRas2G16V allele exhibits increased cellulase gene transcription, the cbh1 and cbh2 expression in this mutant still strictly depends on cellulose, indicating TrRas2 does not directly mediate the transmission of the cellulose signal. In addition, our data suggest that the effect of TrRas2 on cellulase gene is exerted through regulation of transcript abundance of cellulase transcription factors such as Xyr1, but the influence is independent of cAMP signalling pathway. Conclusions/Significance Together, these findings elucidate the functions for Ras signalling of T. reesei in cellular morphogenesis, especially in cellulase gene expression, which contribute to deciphering the

Cellulase production in a new mutant strain of Penicillium decumbens ML-017 by solid state fermentation with rice bran.

PubMed

Liu, Yun-Tao; Luo, Ze-Yu; Long, Chuan-Nan; Wang, Hai-Dong; Long, Min-Nan; Hu, Zhong

2011-10-01

To produce cellulolytic enzyme efficiently, Penicillium decumbens strain L-06 was used to prepare mutants with ethyl methane sulfonate (EMS) and UV-irradiation. A mutant strain ML-017 is shown to have a higher cellulase activity than others. Box-Behnken's design (BBD) and response surface methodology (RSM) were adopted to optimize the conditions of cellulase (filter paper activity, FPA) production in strain ML-017 by solid-state fermentation (SSF) with rice bran as the substrate. And the result shows that the initial pH, moisture content and culture temperature all have significant effect on the production of cellulase. The optimized condition shall be initial pH 5.7, moisture content 72% and culture temperature 30°C. The maximum cellulase (FPA) production was obtained under the optimized condition, which is 5.76 IU g(-1), increased by 44.12% to its original strain. It corresponded well with the calculated results (5.15 IU g(-1)) by model prediction. The result shows that both BBD and RSM are the cellulase optimization methods with good prospects. Copyright © 2011 Elsevier B.V. All rights reserved.

Rce1, a novel transcriptional repressor, regulates cellulase gene expression by antagonizing the transactivator Xyr1 in Trichoderma reesei.

PubMed

Cao, Yanli; Zheng, Fanglin; Wang, Lei; Zhao, Guolei; Chen, Guanjun; Zhang, Weixin; Liu, Weifeng

2017-07-01

Cellulase gene expression in the model cellulolytic fungus Trichoderma reesei is supposed to be controlled by an intricate regulatory network involving multiple transcription factors. Here, we identified a novel transcriptional repressor of cellulase gene expression, Rce1. Disruption of the rce1 gene not only facilitated the induced expression of cellulase genes but also led to a significant delay in terminating the induction process. However, Rce1 did not participate in Cre1-mediated catabolite repression. Electrophoretic mobility shift (EMSA) and DNase I footprinting assays in combination with chromatin immunoprecipitation (ChIP) demonstrated that Rce1 could bind directly to a cbh1 (cellobiohydrolase 1-encoding) gene promoter region containing a cluster of Xyr1 binding sites. Furthermore, competitive binding assays revealed that Rce1 antagonized Xyr1 from binding to the cbh1 promoter. These results indicate that intricate interactions exist between a variety of transcription factors to ensure tight and energy-efficient regulation of cellulase gene expression in T. reesei. This study also provides important clues regarding increased cellulase production in T. reesei. © 2017 John Wiley & Sons Ltd.

Chimeric Cellulase Matrix for Investigating Intramolecular Synergism between Non-hydrolytic Disruptive Functions of Carbohydrate-binding Modules and Catalytic Hydrolysis*

PubMed Central

Wang, Yuguo; Tang, Rentao; Tao, Jin; Wang, Xiaonan; Zheng, Baisong; Feng, Yan

2012-01-01

The conversion of renewable cellulosic biomass is of considerable interest for the production of biofuels and materials. The bottleneck in the efficient conversion is the compactness and resistance of crystalline cellulose. Carbohydrate-binding modules (CBMs), which disrupt crystalline cellulose via non-hydrolytic mechanisms, are expected to overcome this bottleneck. However, the lack of convenient methods for quantitative analysis of the disruptive functions of CBMs have hindered systematic studies and molecular modifications. Here we established a practical and systematic platform for quantifying and comparing the non-hydrolytic disruptive activities of CBMs via the synergism of CBMs and a catalytic module within designed chimeric cellulase molecules. Bioinformatics and computational biology were also used to provide a deeper understanding. A convenient vector was constructed to serve as a cellulase matrix into which heterologous CBM sequences can be easily inserted. The resulting chimeric cellulases were suitable for studying disruptive functions, and their activities quantitatively reflected the disruptive functions of CBMs on crystalline cellulose. In addition, this cellulase matrix can be used to construct novel chimeric cellulases with high hydrolytic activities toward crystalline cellulose. PMID:22778256

Chimeric cellulase matrix for investigating intramolecular synergism between non-hydrolytic disruptive functions of carbohydrate-binding modules and catalytic hydrolysis.

PubMed

Wang, Yuguo; Tang, Rentao; Tao, Jin; Wang, Xiaonan; Zheng, Baisong; Feng, Yan

2012-08-24

The conversion of renewable cellulosic biomass is of considerable interest for the production of biofuels and materials. The bottleneck in the efficient conversion is the compactness and resistance of crystalline cellulose. Carbohydrate-binding modules (CBMs), which disrupt crystalline cellulose via non-hydrolytic mechanisms, are expected to overcome this bottleneck. However, the lack of convenient methods for quantitative analysis of the disruptive functions of CBMs have hindered systematic studies and molecular modifications. Here we established a practical and systematic platform for quantifying and comparing the non-hydrolytic disruptive activities of CBMs via the synergism of CBMs and a catalytic module within designed chimeric cellulase molecules. Bioinformatics and computational biology were also used to provide a deeper understanding. A convenient vector was constructed to serve as a cellulase matrix into which heterologous CBM sequences can be easily inserted. The resulting chimeric cellulases were suitable for studying disruptive functions, and their activities quantitatively reflected the disruptive functions of CBMs on crystalline cellulose. In addition, this cellulase matrix can be used to construct novel chimeric cellulases with high hydrolytic activities toward crystalline cellulose.

Isolation and characterization of Bacillus subtilis strain BY-3, a thermophilic and efficient cellulase-producing bacterium on untreated plant biomass.

PubMed

Meng, F; Ma, L; Ji, S; Yang, W; Cao, B

2014-09-01

Bioconversion of biomass, particularly crop wastes, into biofuels is being developed as an alternative approach in meeting the high energy demand. In this study, a thermophilic bacterial strain BY-3 that exhibits cellulolytic potential was isolated from faecal samples of Tibetan pigs; this strain was identified as Bacillus subtilis. The strain can produce cellulase when grown on various substrates, including carboxymethyl cellulose, rice straw, corn stover, soluble starch and wheat bran. The maximum cellulase activity of the strain was up to 4·323 ± 0·065 U ml(-1) when cultivated in the medium containing corn stover (30 g l(-1) ) for 24 h. The results demonstrated that corn stover is the most suitable substrate for cellulase production by the strain BY-3. The crude cellulase of strain BY-3 was most active at pH 5·5 and 60°C, and the enzyme in acetate buffer (50 mmol l(-1) ) demonstrated a good stability at 60°C for at least 1 h. The crude cellulase exhibited a strong antibacterial activity against Staphylococcus aureus. The strain can be used in cost-efficient cellulase production for bioconversion of agricultural residual biomass into biofuels. The increased consumption of fossil fuels has caused serious energy crisis and environmental problem. Thus, an alternative energy source is necessary. Bioconversion of biomass, particularly agricultural residuals, into value-added bioproducts, such as biofuels and chemical solvents, has received considerable attention. In this study, the newly isolated thermophilic Bacillus subtilis strain BY-3 produces cellulase efficiently with the use of untreated corn stover as a sole carbon source. This strain possesses the thermostable cellulase that is active with diverse crop wastes with a broad pH range and is a highly promising candidate for agricultural waste management. © 2014 The Society for Applied Microbiology.

Fabrication of graphene oxide decorated with Fe3O4@SiO2 for immobilization of cellulase

NASA Astrophysics Data System (ADS)

Li, Yue; Wang, Xiang-Yu; Jiang, Xiao-Ping; Ye, Jing-Jing; Zhang, Ye-Wang; Zhang, Xiao-Yun

2015-01-01

Fe3O4@SiO2-graphene oxide (GO) composites were successfully fabricated by chemical binding of functional Fe3O4@SiO2 and GO and applied to immobilization of cellulase via covalent attachment. The prepared composites were further characterized by transmission electron microscopy and Fourier transform infrared spectroscopy. Fe3O4 nanoparticles (NPs) were monodisperse spheres with a mean diameter of 17 ± 0.2 nm. The thickness of SiO2 layer was calculated as being 6.5 ± 0.2 nm. The size of Fe3O4@SiO2 NPs was 24 ± 0.3 nm, similar to that of Fe3O4@SiO2-NH2. Fe3O4@SiO2-GO composites were synthesized by linking of Fe3O4@SiO2-NH2 NPs to GO with the catalysis of EDC and NHS. The prepared composites were used for immobilization of cellulase. A high immobilization yield and efficiency of above 90 % were obtained after the optimization. The half-life of immobilized cellulase (722 min) was 3.34-fold higher than that of free enzyme (216 min) at 50 °C. Compared with the free cellulase, the optimal temperature of the immobilized enzyme was not changed; but the optimal pH was shifted from 5.0 to 4.0, and the thermal stability was enhanced. The immobilized cellulase could be easily separated and reused under magnetic field. These results strongly indicate that the cellulase immobilized onto the Fe3O4@SiO2-GO composite has potential applications in the production of bioethanol.