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1

Hydrolysates of lignocellulosic materials for biohydrogen production  

Directory of Open Access Journals (Sweden)

Full Text Available Lignocellulosic materials are commonly used in bio-H2 productionfor the sustainable energy resource development asthey are abundant, cheap, renewable and highly biodegradable.In the process of the bio-H2 production, the pretreated lignocellulosicmaterials are firstly converted to monosaccharidesby enzymolysis and then to H2 by fermentation. Since thestructures of lignocellulosic materials are rather complex, thehydrolysates vary with the used materials. Even using the samelignocellulosic materials, the hydrolysates also change withdifferent pretreatment methods. It has been shown that the appropriatehydrolysate compositions can dramatically improvethe biological activities and bio-H2 production performances.Over the past decades, hydrolysis with respect to differentlignocellulosic materials and pretreatments has been widelyinvestigated. Besides, effects of the hydrolysates on the biohydrogenyields have also been examined. In this review, recentstudies on hydrolysis as well as their effects on the biohydrogenproduction performance are summarized. [BMBReports 2013; 46(5: 244-251

Rong Chen

2013-05-01

2

Ethanolic fermentation of pentoses in lignocellulose hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

In the fermentation of lignocellulose hydrolysates to ethanol, two major problems are encountered: the fermentation of the pentose sugar xylose, and the presence of microbial inhibitors. Xylose can be directly fermented with yeasts; such as Pachysolen tannophilus, Candida shehatae, and Pichia stipis, or by isomerization of xylose to xylulose with the enzyme glucose (xylose) isomerase, and subsequent fermentation with bakers yeast, Saccharomyces cerevisiae. The direct fermentation requires low, carefully controlled oxygenation, as well as the removal of inhibitors. Also, the xylose-fermenting yeasts have a limited ethanol tolerance. The combined isomerization and fermentation with XI and S. cerevisiae gives yields and productivities comparable to those obtained in hexose fermentations without oxygenation and removal of inhibitors. However, the enzyme is not very stable in a lignocellulose hydrolysate, and S. cerevisiae has a poorly developed pentose phosphate shunt. Different strategies involving strain adaptation, and protein and genetic engineering adopted to overcome these different obstacles, are discussed.

Hahn-Haegerdal, B.; Linden, T.; Senac, T.; Skoog, K. [Lund Univ. Chemical Center (Sweden)

1991-12-31

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The fermentation of lignocellulose hydrolysates with xylose isomerases and yeasts  

Energy Technology Data Exchange (ETDEWEB)

Untreated spent sulphite liquor (SSL) was fermented with Canida tropicalis, Pichia stipitis, Pachysolen tannophilus, Schizosaccharomyces pombe, Saccharomyces cerevisiae and a co-culture of P. Tannophilus and A. cerevisiae, in the presence of xylose isomerases and 4.6 mM azide. The highest yield of ethanol, 0.41 g/g total sugar was obtained with S. cerevisiae, C. tropicalis, and P. tannophilus produced considerble amounts of polyoles, mainly xylitol. With P. stipitis sugar uptake was rapidly inhibited in untreated SSL. The presence of azide contributed to the yield by about 0.04. The fermentation of hydrogen fluoride-pretreated and acid-hydrolysed wheat straw with S. cerevisiae, xylose isomerase, and azide gave a yield of 0.40 g ethanol/g total sugar. In this substrate the xylose utilisation was 84% compared with 51% in SSL. In the concentration range appropriate for enzymatic xylose isomerization, xylulose was measured in a lignocellulose hydrolysate using HPLC with two hydrogen loaded ion exchange columns in series. SSL was used as a model for lignocellulose hydrolysates. The enzymatic isomerization of xylose to xylulose was followed directly in SSL, providing a method for the direct determination of xylose isomerase activity in lignocellulose hydrolysates. Three different xylose isomerase preparations of L. brevis whole cells were compared with a commercial enzyme preparation Maxazyme GI-immob., with respect to activity and stability. From a continuous SSL fermentation plant, two species of yeasts were isolated, S. cerevisiae and Pichia membranaefaciens. One of the isolates of S. cerevisiae, no. 3 was heavily flocculating. Without acetic acid present, both bakers` yeast and isolate no. 3 showed catabolite repression and fermented glucose and galactose sequentially. Galactose fermentation with bakers` yeast was strongly inhibited by acetic acid at pH values below 6. Isolate no. 3 fermented galactose, glucose and mannose, in the presence of acetic acid even at pH.

Linden, T.

1992-09-01

4

The fermentation of lignocellulose hydrolysates with xylose isomerases and yeasts  

Energy Technology Data Exchange (ETDEWEB)

Untreated spent sulphite liquor (SSL) was fermented with Canida tropicalis, Pichia stipitis, Pachysolen tannophilus, Schizosaccharomyces pombe, Saccharomyces cerevisiae and a co-culture of P. Tannophilus and A. cerevisiae, in the presence of xylose isomerases and 4.6 mM azide. The highest yield of ethanol, 0.41 g/g total sugar was obtained with S. cerevisiae, C. tropicalis, and P. tannophilus produced considerble amounts of polyoles, mainly xylitol. With P. stipitis sugar uptake was rapidly inhibited in untreated SSL. The presence of azide contributed to the yield by about 0.04. The fermentation of hydrogen fluoride-pretreated and acid-hydrolysed wheat straw with S. cerevisiae, xylose isomerase, and azide gave a yield of 0.40 g ethanol/g total sugar. In this substrate the xylose utilisation was 84% compared with 51% in SSL. In the concentration range appropriate for enzymatic xylose isomerization, xylulose was measured in a lignocellulose hydrolysate using HPLC with two hydrogen loaded ion exchange columns in series. SSL was used as a model for lignocellulose hydrolysates. The enzymatic isomerization of xylose to xylulose was followed directly in SSL, providing a method for the direct determination of xylose isomerase activity in lignocellulose hydrolysates. Three different xylose isomerase preparations of L. brevis whole cells were compared with a commercial enzyme preparation Maxazyme GI-immob., with respect to activity and stability. From a continuous SSL fermentation plant, two species of yeasts were isolated, S. cerevisiae and Pichia membranaefaciens. One of the isolates of S. cerevisiae, no. 3 was heavily flocculating. Without acetic acid present, both bakers' yeast and isolate no. 3 showed catabolite repression and fermented glucose and galactose sequentially. Galactose fermentation with bakers' yeast was strongly inhibited by acetic acid at pH values below 6. Isolate no. 3 fermented galactose, glucose and mannose, in the presence of acetic acid even at pH.

Linden, T.

1992-01-01

5

Fermentation of lignocellulosic hydrolysates: Inhibition and detoxification  

Energy Technology Data Exchange (ETDEWEB)

The ethanol yield and productivity obtained during fermentation of lignocellulosic hydrolysates is decreased due to the presence of inhibiting compounds, such as weak acids, furans and phenolic compounds produced during hydrolysis. Evaluation of the effect of various biological, physical and chemical detoxification treatments by fermentation assays using Saccharomyces cerevisiae was used to characterise inhibitors. Inhibition of fermentation was decreased after removal of the non-volatile compounds, pre-fermentation by the filamentous fungus Trichoderma reesei, treatment with the lignolytic enzyme laccase, extraction with ether, and treatment with alkali. Yeast growth in lignocellulosic hydrolysates was inhibited below a certain fermentation pH, most likely due to high concentrations of undissociated weak acids. The effect of individual compounds were studied in model fermentations. Furfural is reduced to furfuryl alcohol by yeast dehydrogenases, thereby affecting the intracellular redox balance. As a result, acetaldehyde accumulated during furfural reduction, which most likely contributed to inhibition of growth. Acetic acid (10 g 1{sup -1}) and furfural (3 g 1{sup -1}) interacted antagonistically causing decreased specific growth rate, whereas no significant individual or interaction effects were detected by the lignin-derived compound 4-hydroxybenzoic acid (2 g 1{sup -1}). By maintaining a high cell mass density in the fermentor, the process was less sensitive to inhibitors affecting growth and to fluctuations in fermentation pH, and in addition the depletion rate of bioconvertible inhibitors was increased. A theoretical ethanol yield and high productivity was obtained in continuous fermentation of spruce hydrolysate when the cell mass concentration was maintained at a high level by applying cell recirculation 164 refs, 16 figs, 5 tabs

Palmqvist, E.

1998-02-01

6

Production of Succinic Acid for Lignocellulosic Hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

The purpose of this Cooperative Research and Development Agreement (CRADA) is to add and test new metabolic activities to existing microbial catalysts for the production of succinic acid from renewables. In particular, they seek to add to the existing organism the ability to utilize xylose efficiently and simultaneously with glucose in mixtures of sugars or to add succinic acid production to another strain and to test the value of this new capability for production of succinic acid from industrial lignocellulosic hydrolyasates. The Contractors and Participant are hereinafter jointly referred to as the 'Parties'. Research to date in succinic acid fermentation, separation and genetic engineering has resulted in a potentially economical process based on the use of an Escherichia coli strain AFP111 with suitable characteristics for the production of succinic acid from glucose. Economic analysis has shown that higher value commodity chemicals can be economically produced from succinic acid based on repliminary laboratory findings and predicted catalytic parameters. The initial target markets include succinic acid itself, succinate salts, esters and other derivatives for use as deicers, solvents and acidulants. The other commodity products from the succinic acid platform include 1,4-butanediol, {gamma}-butyrolactone, 2-pyrrolidinone and N-methyl pyrrolidinone. Current economic analyses indicate that this platform is competitive with existing petrochemical routes, especially for the succinic acid and derivatives. The report presents the planned CRADA objectives followed by the results. The results section has a combined biocatalysis and fermentation section and a commercialization section. This is a nonproprietary report; additional proprietary information may be made available subject to acceptance of the appropriate proprietary information agreements.

Davison, B.H.; Nghiem, J.

2002-06-01

7

Use of an algal hydrolysate to improve enzymatic hydrolysis of lignocellulose.  

Science.gov (United States)

This study investigated the use of acid hydrolyzed algae to enhance the enzymatic hydrolysis of lignocellulosic biomass. The farm-waste grown algal samples were first characterized, and the optimal conditions for algal hydrolysis using dilute sulfuric acid were determined. Neutralized algal hydrolysate was then tested as a reaction medium (replacing the pH buffer solution) for the enzymatic hydrolysis of a lignocellulose, alkali treated anaerobically-digested fiber. Our results showed that net glucose yields from enzymatic hydrolyses containing undiluted algal hydrolysate were at least 65% higher than net glucose yields from control media (bovine serum albumin solution, citrate buffer or distilled water). It is likely that the increase in net glucose yield is due, in part, to the binding of hydrolyzed algal proteins to lignin, which protects cellulase from binding to lignin. This study demonstrates a potential approach of using wastewater-grown algae as a co-substrate to significantly enhance the enzymatic hydrolysis of lignocellulosic materials. PMID:22277211

Chen, Rui; Yue, Zhengbo; Deitz, Lauren; Liu, Yan; Mulbry, Walter; Liao, Wei

2012-03-01

8

Death by a thousand cuts: the challenges and diverse landscape of lignocellulosic hydrolysate inhibitors  

OpenAIRE

Lignocellulosic hydrolysate (LCH) inhibitors are a large class of bioactive molecules that arise from pretreatment, hydrolysis, and fermentation of plant biomass. These diverse compounds reduce lignocellulosic biofuel yields by inhibiting cellular processes and diverting energy into cellular responses. LCH inhibitors present one of the most significant challenges to efficient biofuel production by microbes. Development of new strains that lessen the effects of LCH inhibitors is an economicall...

JeffScottPiotrowski

2014-01-01

9

Evolutionary engineering of Saccharomyces cerevisiae for enhanced tolerance to hydrolysates of lignocellulosic biomass.  

Science.gov (United States)

Lignocellulosic biomass has become an important feedstock to mitigate current ethical and economical concerns related to the bio-based production of fuels and chemicals. During the pre-treatment and hydrolysis of the lignocellulosic biomass, a complex mixture of sugars and inhibitors are formed. The inhibitors interfere with microbial growth and product yields. This study uses an adaptive laboratory evolution method called visualizing evolution in real-time (VERT) to uncover the molecular mechanisms associated with tolerance to hydrolysates of lignocellulosic biomass in Saccharomyces cerevisiae. VERT enables a more rational scheme for isolating adaptive mutants for characterization and molecular analyses. Subsequent growth kinetic analyses of the mutants in individual and combinations of common inhibitors present in hydrolysates (acetic acid, furfural, and hydroxymethylfurfural) showed differential levels of resistance to different inhibitors, with enhanced growth rates up to 57%, 12%, 22%, and 24% in hydrolysates, acetic acid, HMF and furfural, respectively. Interestingly, some of the adaptive mutants exhibited reduced fitness in the presence of individual inhibitors, but showed enhanced fitness in the presence of combinations of inhibitors compared to the parental strains. Transcriptomic analysis revealed different mechanisms for resistance to hydrolysates and a potential cross adaptation between oxidative stress and hydrolysates tolerance in several of the mutants. PMID:23613173

Almario, María P; Reyes, Luis H; Kao, Katy C

2013-10-01

10

Death by a thousand cuts: the challenges and diverse landscape of lignocellulosic hydrolysate inhibitors  

Science.gov (United States)

Lignocellulosic hydrolysate (LCH) inhibitors are a large class of bioactive molecules that arise from pretreatment, hydrolysis, and fermentation of plant biomass. These diverse compounds reduce lignocellulosic biofuel yields by inhibiting cellular processes and diverting energy into cellular responses. LCH inhibitors present one of the most significant challenges to efficient biofuel production by microbes. Development of new strains that lessen the effects of LCH inhibitors is an economically favorable strategy relative to expensive detoxification methods that also can reduce sugar content in deconstructed biomass. Systems biology analyses and metabolic modeling combined with directed evolution and synthetic biology are successful strategies for biocatalyst development, and methods that leverage state-of-the-art tools are needed to overcome inhibitors more completely. This perspective considers the energetic costs of LCH inhibitors and technologies that can be used to overcome their drain on conversion efficiency. We suggest academic and commercial research groups could benefit by sharing data on LCH inhibitors and implementing “translational biofuel research.” PMID:24672514

Piotrowski, Jeff S.; Zhang, Yaoping; Bates, Donna M.; Keating, David H.; Sato, Trey K.; Ong, Irene M.; Landick, Robert

2014-01-01

11

Death by a thousand cuts: the challenges and diverse landscape of lignocellulosic hydrolysate inhibitors.  

Science.gov (United States)

Lignocellulosic hydrolysate (LCH) inhibitors are a large class of bioactive molecules that arise from pretreatment, hydrolysis, and fermentation of plant biomass. These diverse compounds reduce lignocellulosic biofuel yields by inhibiting cellular processes and diverting energy into cellular responses. LCH inhibitors present one of the most significant challenges to efficient biofuel production by microbes. Development of new strains that lessen the effects of LCH inhibitors is an economically favorable strategy relative to expensive detoxification methods that also can reduce sugar content in deconstructed biomass. Systems biology analyses and metabolic modeling combined with directed evolution and synthetic biology are successful strategies for biocatalyst development, and methods that leverage state-of-the-art tools are needed to overcome inhibitors more completely. This perspective considers the energetic costs of LCH inhibitors and technologies that can be used to overcome their drain on conversion efficiency. We suggest academic and commercial research groups could benefit by sharing data on LCH inhibitors and implementing "translational biofuel research." PMID:24672514

Piotrowski, Jeff S; Zhang, Yaoping; Bates, Donna M; Keating, David H; Sato, Trey K; Ong, Irene M; Landick, Robert

2014-01-01

12

Isolation of filamentous fungi exhibiting high endoxylanase activity in lignocellulose hydrolysate.  

Science.gov (United States)

For complete degradation of hemicellulose into its monomers from lignocellulose biomass, the synergistic action of a broad range of hydrolytic enzymes is needed. Therefore, production of enzymes from their natural producer is desirable. To obtain a powerful ?-1,4-endoxylanase producing fungus, 304 environmental samples were collected from various locations in Singapore, leading to 603 isolates. Among them, 71 exhibiting ?-1,4-endoxylanase activity were identified belonging mainly to the genera of Aspergillus, Penicillium, and Trichoderma. Further analysis revealed Aspergillus niger DSM 26641 as a potential and stable ?-1,4-endoxylanase producer, being able to grow in hydrothermal lignocellulose hydrolysate exhibiting its maximal ?-1,4-endoxylanase activity at pH 4 and 60 °C. This strain is thought to be very suitable for lactic acid production in a simultaneous saccharification and fermentation at pH values below 5. PMID:25432348

Ottenheim, Christoph; Meier, Kirstin; Zimmermann, Wolfgang; Wu, Jin Chuan

2015-02-01

13

Effects of inhibitory compounds in lignocellulosic hydrolysates on Mortierella isabellina growth and carbon utilization.  

Science.gov (United States)

Oleaginous fungus Mortierella isabellina showed excellent lipid conversion on non-detoxified lignocellulosic hydrolysate. This study investigated the effects of inhibitory compounds (furfural, hydroxymethylfurfural, and ferulic and coumaric acids) in lignocellulosic hydrolysate on M. isabellina growth and lipid production. M. isabellina can tolerate furfural (?1g/L), hydroxymethylfurfural (?2.5g/L), ferulic (?0.5g/L) and coumaric acid (?0.5g/L) with normal growth rates. Synergistic effect of these inhibitors (2g/L furfural, 0.4g/L hydroxymethylfurfural, 0.02g/L ferulic acid and 0.02g/L coumaric acid) moderately reduces total fungal growth (by 28%), while the presence of these inhibitors has minor impact on cell lipid contents and lipid profiles. In the presence of inhibitory compounds, (13)C-tracing has revealed that M. isabellina can simultaneously utilize glucose and acetate, and acetate is mainly assimilated for synthesis of lipid and TCA cycle amino acids. The results also demonstrate that glucose has strong catabolite repression for xylose utilization for biomass and lipid production in the presence of inhibitors. PMID:25710679

Ruan, Zhenhua; Hollinshead, Whitney; Isaguirre, Christine; Tang, Yinjie J; Liao, Wei; Liu, Yan

2015-05-01

14

Death by a thousand cuts: the challenges and diverse landscape of lignocellulosic hydrolysate inhibitors  

Directory of Open Access Journals (Sweden)

Full Text Available Lignocellulosic hydrolysate (LCH inhibitors are a large class of bioactive molecules that arise from pretreatment, hydrolysis, and fermentation of plant biomass. These diverse compounds reduce lignocellulosic biofuel yields by inhibiting cellular processes and diverting energy into cellular responses. LCH inhibitors present one of the most significant challenges to efficient biofuel production by microbes. Development of new strains that lessen the effects of LCH inhibitors is an economically favorable strategy relative to expensive detoxification methods that also can reduce sugar content in deconstructed biomass. Systems biology analyses and metabolic modeling combined with directed evolution and synthetic biology are successful strategies for biocatalyst development, and methods that leverage state-of-the-art tools are needed to overcome inhibitors more completely. This perspective considers the energetic costs of LCH inhibitors and technologies that can be used to overcome their drain on conversion efficiency. We suggest academic and commercial research groups could benefit by sharing data on LCH inhibitors and implementing “translational biofuel research.”

JeffScottPiotrowski

2014-03-01

15

Effect of lignin-derived and furan compounds found in lignocellulosic hydrolysates on biomethane production.  

Science.gov (United States)

Hydrolysates resulting from the lignocellulosic biomass pretreatment in bioethanol production may be used to produce biogas. Such hydrolysates are rich in xylose but also contain lignin polymers or oligomers as well as phenolic and furan compounds, such as syringaldehyde, vanillin, HMF, furfural. The aim of this study was to investigate the impact of these byproducts on biomethane production from xylose. The anaerobic digestion of the byproducts alone was also investigated. No inhibition of the anaerobic digestion of xylose was observed and methane was obtained from furans: 430 mL CH(4)/g of furfural and 450 mL CH(4)/g of HMF; from phenolic compounds: 453 mL CH(4)/g of syringaldehyde and 105 mL CH(4)/g of vanillin; and, to a lesser extent, from lignin polymers: from 14 to 46 mL CH(4)/g MV. The use of different natural polymers (lignosulfonates, organosolv and kraft lignins) and synthetic dehydrogenative polymers showed that higher S/G ratios and lower molecular weights in lignin polymers led to greater methane production. PMID:22100239

Barakat, Abdellatif; Monlau, Florian; Steyer, Jean-Philippe; Carrere, Hélène

2012-01-01

16

Enhanced bioproduction of poly-3-hydroxybutyrate from wheat straw lignocellulosic hydrolysates.  

Science.gov (United States)

Polyhydroxyalkanoates (PHAs) are bioplastics that can replace conventional petroleum-derived products in various applications. One of the major barriers for their widespread introduction in the market is the higher production costs compared with their petrochemical counterparts. In this work, a process was successfully implemented with high productivity based on wheat straw, a cheap and readily available agricultural residue, as raw material. The strain Burkholderia sacchari DSM 17165 which is able to metabolise glucose, xylose and arabinose, the main sugars present in wheat straw hydrolysates (WSHs), was used. Results in shake flask showed that B. sacchari cells accumulated about 70%gpoly(3-hydroxybutyrate)(P(3HB))/g cell dry weight (CDW) with a yield of polymer on sugars (YP/S) of 0.18g/g when grown on a mixture of commercial C6 and C5 sugars (control), while these values reached about 60%gP(3HB)/g CDW and 0.19g/g, respectively, when WSHs were used as carbon source. In fed-batch cultures carried out in 2L stirred-tank reactors (STRs) on WSH, a maximum polymer concentration of 105 g/L was reached after 61 hours of cultivation corresponding to an accumulation of 72% of CDW. Polymer yield and productivity were 0.22 gP(3HB)/g total sugar consumed and 1.6g/L hour, respectively. The selected feeding strategy successfully overcame the carbon catabolite repression (CCR) phenomenon observed with sugar mixtures containing hexoses and pentoses. This is the first work describing fed-batch cultivations aiming at PHA production using real lignocellulosic hydrolysates. Additionally, the P(3HB) volumetric productivities attained are by far the highest ever achieved on agricultural waste hydrolysates. PMID:24157713

Cesário, M Teresa; Raposo, Rodrigo S; de Almeida, M Catarina M D; van Keulen, Frederik; Ferreira, Bruno S; da Fonseca, M Manuela R

2014-01-25

17

Ethanol production by Saccharomyces cerevisiae using lignocellulosic hydrolysate from Chrysanthemum waste degradation.  

Science.gov (United States)

Ethanol production derived from Saccharomyces cerevisiae fermentation of a hydrolysate from floriculture waste degradation was studied. The hydrolysate was produced from Chrysanthemum (Dendranthema grandiflora) waste degradation by Pleurotus ostreatus and characterized to determine the presence of compounds that may inhibit fermentation. The products of hydrolysis confirmed by HPLC were cellobiose, glucose, xylose and mannose. The hydrolysate was fermented by S. cerevisiae, and concentrations of biomass, ethanol, and glucose were determined as a function of time. Results were compared to YGC modified medium (yeast extract, glucose and chloramphenicol) fermentation. Ethanol yield was 0.45 g g(-1), 88 % of the maximal theoretical value. Crysanthemum waste hydrolysate was suitable for ethanol production, containing glucose and mannose with adequate nutrients for S. cerevisiae fermentation and low fermentation inhibitor levels. PMID:23117675

Quevedo-Hidalgo, Balkys; Monsalve-Marín, Felipe; Narváez-Rincón, Paulo César; Pedroza-Rodríguez, Aura Marina; Velásquez-Lozano, Mario Enrique

2013-03-01

18

Lignocellulosic hydrolysates and extracellular electron shuttles for H2 production using co-culture fermentation with Clostridium beijerinckii and Geobacter metallireducens.  

Science.gov (United States)

A co-culture of Clostridium beijerinckii and Geobacter metallireducens with AH2QDS produced hydrogen from lignocellulosic hydrolysates (biomass of Miscanthus prepared by hydrothermal treatment with dilute acids). This co-culture system enhanced hydrogen production from lignocellulosic hydrolysates by improving substrate utilization and diminishing acetate accumulation, despite the presence of fermentation inhibitors in the hydrolysates. The improvements were greater for xylose-rich hydrolysates. The increase in maximum cumulative hydrogen production for hydrolysates with glucose:xylose mass ratios of 1:0.2, 1:1 and 1:10 g/g was 0%, 22% and 11%, respectively. Alternative extracellular electron shuttles (EES), including indigo dye, juglone, lawsone, fulvic acids and humic acids, were able to substitute for AH2QDS, improving hydrogen production in the co-culture system using xylose as model substrate. Increased utilization of xylose-rich hydrolysates and substitution of alternative EES make the co-culture with EES system a more attractive strategy for industrial biohydrogen production. PMID:23994308

Zhang, Xinyu; Ye, Xiaofeng; Guo, Bin; Finneran, Kevin T; Zilles, Julie L; Morgenroth, Eberhard

2013-11-01

19

Enzymatic hydrolysis of brewers' spent grain proteins and technofunctional properties of the resulting hydrolysates.  

Science.gov (United States)

Brewers' spent grain (BSG) is the insoluble residue of barley malt resulting from the manufacture of wort. Although it is the main byproduct of the brewing industry, it has received little attention as a marketable commodity and is mainly used as animal feed. Our work focuses on one of the main constituents of BSG, i.e., the proteins. The lack of solubility of BSG proteins is one of the limitations for their more extensive use in food processing. We therefore aimed to generate BSG protein hydrolysates with improved technofunctional properties. BSG protein concentrate (BPC) was prepared by alkaline extraction of BSG and subsequent acid precipitation. BPC was enzymatically hydrolyzed in a pH-stat setup by several commercially available proteases (Alcalase, Flavourzyme, and Pepsin) for different times and/or with different enzyme concentrations in order to obtain hydrolysates with different degrees of hydrolysis (DH). Physicochemical properties, such as molecular weight (MW) distribution and hydrophobicity, as well as technofunctional properties, such as solubility, color, and emulsifying and foaming properties, were determined. Enzymatic hydrolysis of BPC improved emulsion and/or foam-forming properties. However, for the hydrolysates prepared with Alcalase and Pepsin, an increasing DH generally decreased emulsifying and foam-forming capacities. Moreover, the type of enzyme impacted the resulting technofunctional properties. Hydrolysates prepared with Flavourzyme showed good technofunctional properties, independent of the DH. Physicochemical characterization of the hydrolysates indicated the importance of protein fragments with relatively high MW (exceeding 14.5 k) and high surface hydrophobicity for favorable technofunctional properties. PMID:17896813

Celus, Inge; Brijs, Kristof; Delcour, Jan A

2007-10-17

20

Chloroplast-derived enzyme cocktails hydrolyse lignocellulosic biomass and release fermentable sugars  

OpenAIRE

It is widely recognized that biofuel production from lignocellulosic materials is limited by inadequate technology to efficiently and economically release fermentable sugars from the complex multi-polymeric raw materials. Therefore, endoglucanases, exoglucanase, pectate lyases, cutinase, swollenin, xylanase, acetyl xylan esterase, beta glucosidase and lipase genes from bacteria or fungi were expressed in E. coli or tobacco chloroplasts. A PCR based method was used to clone genes without intro...

Verma, Dheeraj; Kanagaraj, Anderson; Jin, Shuangxia; Singh, Nameirakpam D.; Kolattukudy, Pappachan E.; Daniell, Henry

2010-01-01

21

Development of a Saccharomyces cerevisiae Strain with Enhanced Resistance to Phenolic Fermentation Inhibitors in Lignocellulose Hydrolysates by Heterologous Expression of Laccase  

OpenAIRE

To improve production of fuel ethanol from renewable raw materials, laccase from the white rot fungus Trametes versicolor was expressed under control of the PGK1 promoter in Saccharomyces cerevisiae to increase its resistance to phenolic inhibitors in lignocellulose hydrolysates. It was found that the laccase activity could be enhanced twofold by simultaneous overexpression of the homologous t-SNARE Sso2p. The factors affecting the level of active laccase obtained, besides the cultivation tem...

Larsson, Simona; Cassland, Pierre; Jo?nsson, Leif J.

2001-01-01

22

Chloroplast-derived enzyme cocktails hydrolyse lignocellulosic biomass and release fermentable sugars.  

Science.gov (United States)

It is widely recognized that biofuel production from lignocellulosic materials is limited by inadequate technology to efficiently and economically release fermentable sugars from the complex multi-polymeric raw materials. Therefore, endoglucanases, exoglucanase, pectate lyases, cutinase, swollenin, xylanase, acetyl xylan esterase, beta glucosidase and lipase genes from bacteria or fungi were expressed in Escherichia coli or tobacco chloroplasts. A PCR-based method was used to clone genes without introns from Trichoderma reesei genomic DNA. Homoplasmic transplastomic lines showed normal phenotype and were fertile. Based on observed expression levels, up to 49, 64 and 10, 751 million units of pectate lyases or endoglucanase can be produced annually, per acre of tobacco. Plant production cost of endoglucanase is 3100-fold, and pectate lyase is 1057 or 1480-fold lower than the same recombinant enzymes sold commercially, produced via fermentation. Chloroplast-derived enzymes had higher temperature stability and wider pH optima than enzymes expressed in E. coli. Plant crude-extracts showed higher enzyme activity than E. coli with increasing protein concentration, demonstrating their direct utility without purification. Addition of E. coli extracts to the chloroplast-derived enzymes significantly decreased their activity. Chloroplast-derived crude-extract enzyme cocktails yielded more (up to 3625%) glucose from filter paper, pine wood or citrus peel than commercial cocktails. Furthermore, pectate lyase transplastomic plants showed enhanced resistance to Erwina soft rot. This is the first report of using plant-derived enzyme cocktails for production of fermentable sugars from lignocellulosic biomass. Limitations of higher cost and lower production capacity of fermentation systems are addressed by chloroplast-derived enzyme cocktails. PMID:20070870

Verma, Dheeraj; Kanagaraj, Anderson; Jin, Shuangxia; Singh, Nameirakpam D; Kolattukudy, Pappachan E; Daniell, Henry

2010-04-01

23

Growth of oleaginous Rhodotorula glutinis in an internal-loop airlift bioreactor by using lignocellulosic biomass hydrolysate as the carbon source.  

Science.gov (United States)

The conversion of abundant lignocellulosic biomass (LCB) to valuable compounds has become a very attractive idea recently. This study successfully used LCB (rice straw) hydrolysate as a carbon source for the cultivation of oleaginous yeast-Rhodotorula glutinis in an airlift bioreactor. The lipid content of 34.3 ± 0.6% was obtained in an airlift batch with 60 g reducing sugars/L of LCB hydrolysate at a 2 vvm aeration rate. While using LCB hydrolysate as the carbon source, oleic acid (C18:1) and linoleic acid (C18:2) were the predominant fatty acids of the microbial lipids. Using LCB hydrolysate in the airlift bioreactor at 2 vvm achieved the highest cell mass growth as compared to the agitation tank. Despite the low lipid content of the batch using LCB hydrolysate, this low cost feedstock has the potential of being adopted for the production of ?-carotene instead of lipid accumulation in the airlift bioreactor for the cultivation of R. glutinis. PMID:25454603

Yen, Hong-Wei; Chang, Jung-Tzu

2015-05-01

24

Production of modified bentonite via adsorbing lignocelluloses from spent liquor of NSSC process.  

Science.gov (United States)

In this work, the adsorption of lignocelluloses from spent liquor (SL) of neutral sulfite semi chemical (NSSC) pulping process on bentonite was investigated. It was observed that 0.26g/g of lignin and 0.27g/g of hemicelluloses from SL were adsorbed on bentonite under the conditions of 50°C, 100rpm and 40g/gSL/bentonite after 3h of treatment. The adsorptions of lignin and hemicellulose were increased to 1.8g/g and 0.45g/g, respectively, via adding 15mg/g of polydiallyldimethylammonium chloride (PDADMAC) in the system of SL/bentonite. The turbidity and COD removals were improved from 69% to 93% and from 25% to 38% by adding PDADMAC to the SL/bentonite system, respectively. The increase in the heating value of bentonite (from 0 to 15.4MJ/kg) confirmed the adsorption of lignocelluloses. The modified bentonite can be used as filler in corrugated medium paper production or as fuel. PMID:25463794

Oveissi, Farshad; Fatehi, Pedram

2014-12-01

25

Biorefining of lignocellulose : Detoxification of inhibitory hydrolysates and potential utilization of residual streams for production of enzymes  

OpenAIRE

Lignocellulosic biomass is a renewable resource that can be utilized for the production of biofuels, chemicals, and bio-based materials. Biochemical conversion of lignocellulose to advanced biofuels, such as cellulosic ethanol, is generally performed through microbial fermentation of sugars generated by thermochemical pretreatment of the biomass followed by an enzymatic hydrolysis of the cellulose. The aims of the research presented in this thesis were to address problems associated with pret...

Cavka, Adnan

2013-01-01

26

SUMO expression shortens the lag phase of Saccharomyces cerevisiae yeast growth caused by complex interactive effects of major mixed fermentation inhibitors found in hot-compressed water-treated lignocellulosic hydrolysate.  

Science.gov (United States)

The complex inhibitory effects of inhibitors present in lignocellulose hydrolysate suppress the ethanol fermentation of Saccharomyces cerevisiae. Although the interactive inhibitory effects play important roles in the actual hydrolysate, few studies have investigated glycolaldehyde, the key inhibitor of hot-compressed water-treated lignocellulose hydrolysate. Given this challenge, we investigated the interactive effects of mixed fermentation inhibitors, including glycolaldehyde. First, we confirmed that glycolaldehyde was the most potent inhibitor in the hydrolysate and exerted interactive inhibitory effects in combination with major inhibitors. Next, through genome-wide analysis and megavariate data modeling, we identified SUMOylation as a novel potential mechanism to overcome the combinational inhibitory effects of fermentation inhibitors. Indeed, overall SUMOylation was increased and Pgk1, which produces an ATP molecule in glycolysis by substrate-level phosphorylation, was SUMOylated and degraded in response to glycolaldehyde. Augmenting the SUMO-dependent ubiquitin system in the ADH1-expressing strain significantly shortened the lag phase of growth, released cells from G2/M arrest, and improved energy status and glucose uptake in the inhibitor-containing medium. In summary, our study was the first to establish SUMOylation as a novel platform for regulating the lag phase caused by complex fermentation inhibitors. PMID:25359478

Jayakody, Lahiru N; Kadowaki, Masafumi; Tsuge, Keisuke; Horie, Kenta; Suzuki, Akihiro; Hayashi, Nobuyuki; Kitagaki, Hiroshi

2015-01-01

27

Brewers' spent grain (BSG) protein hydrolysates decrease hydrogen peroxide (H2O2)-induced oxidative stress and concanavalin-A (con-A) stimulated IFN-? production in cell culture.  

Science.gov (United States)

The present study investigated the bioactivity of protein hydrolysates and fractionated hydrolysates prepared from brewers' spent grain (BSG) using proteases, including Alcalase 2.4L, Flavourzyme and Corolase PP. Hydrolysates were designated K-Y, including fractionated hydrolysates with molecular weight (m.w.) 5 kDa. Where computable, IC50 values were lower in U937 (1.38-9.78%) than Jurkat T cells (1.15-13.82%). Hydrolysates L, Q and R and fractionated hydrolysates of U and W (5 kDa) significantly (P 5 kDa, V, V > 5 kDa, W, W > 5 kDa significantly (P 5 kDa) possess anti-inflammatory effects. PMID:24113874

McCarthy, Aoife L; O'Callaghan, Yvonne C; Connolly, Alan; Piggott, Charles O; FitzGerald, Richard J; O'Brien, Nora M

2013-11-01

28

Sophorolipid production from biomass hydrolysates.  

Science.gov (United States)

Although extensive research has been conducted on producing sophorolipids using Candida (Starmerella) bombicola from pure sugars and various oil sources, production of this biosurfactant has not been evaluated when cells are cultivated in lignocellulosic hydrolysates. Here, we report for the first time that C. bombicola is capable of producing sophorolipids on hydrolysates derived from sweet sorghum bagasse and corn fiber. Without oil supplementation, a sophorolipid concentration of 3.6 and 1.0 g/L was detected from cultures with bagasse and corn fiber hydrolysates, respectively. With the addition of soybean oil at 100 g/L, the yield of sophorolipids from these two hydrolysates in the same order was 84.6 and 15.6 g/L. Surprisingly, C. bombicola consumed all monomeric sugars and nonsugar compounds in the hydrolysates, and cultures with bagasse hydrolysates had higher yield of sophorolipids than those from a standard medium which contained pure glucose at the same concentration. PMID:25475889

Samad, Abdul; Zhang, Ji; Chen, Da; Liang, Yanna

2015-02-01

29

Second Generation Ethanol Production from Brewers’ Spent Grain  

Directory of Open Access Journals (Sweden)

Full Text Available Ethanol production from lignocellulosic biomasses raises a global interest because it represents a good alternative to petroleum-derived energies and reduces the food versus fuel conflict generated by first generation ethanol. In this study, alkaline-acid pretreated brewers’ spent grain (BSG was evaluated for ethanol production after enzymatic hydrolysis with commercial enzymes. The obtained hydrolysate containing a glucose concentration of 75 g/L was adopted, after dilution up to 50 g/L, for fermentation by the strain Saccharomyces cerevisiae NRRL YB 2293 selected as the best producer among five ethanologenic microorganims. When the hydrolysate was supplemented with yeast extract, 12.79 g/L of ethanol, corresponding to 0.28 g of ethanol per grams of glucose consumed (55% efficiency, was obtained within 24 h, while in the non-supplemented hydrolysate, a similar concentration was reached within 48 h. The volumetric productivity increased from 0.25 g/L·h in the un-supplemented hydrolysate to 0.53 g/L h in the yeast extract supplemented hydrolysate. In conclusion, the strain S. cerevisiae NRRL YB 2293 was shown able to produce ethanol from BSG. Although an equal amount of ethanol was reached in both BSG hydrolysate media, the nitrogen source supplementation reduced the ethanol fermentation time and promoted glucose uptake and cell growth.

Rossana Liguori

2015-03-01

30

Effect of Lignocellulose Related Compounds on Microalgae Growth and Product Biosynthesis: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available Microalgae contain valuable compounds that can be harnessed for industrial applications. Lignocellulose biomass is a plant material containing in abundance organic substances such as carbohydrates, phenolics, organic acids and other secondary compounds. As growth of microalgae on organic substances was confirmed during heterotrophic and mixotrophic cultivation, lignocellulose derived compounds can become a feedstock to cultivate microalgae and produce target compounds. In this review, different treatment methods to hydrolyse lignocellulose into organic substrates are presented first. Secondly, the effect of lignocellulosic hydrolysates, organic substances typically present in lignocellulosic hydrolysates, as well as minor co-products, on growth and accumulation of target compounds in microalgae cultures is described. Finally, the possibilities of using lignocellulose hydrolysates as a common feedstock for microalgae cultures are evaluated.

Krystian Miazek

2014-07-01

31

Dried Spent Yeast and Its Hydrolysate as Nitrogen Supplements for Single Batch and Repeated-Batch Ethanol Fermentation from Sweet Sorghum Juice  

Directory of Open Access Journals (Sweden)

Full Text Available Dried spent yeast (DSY and its hydrolysate (DSYH were used as low-cost nitrogen supplements to improve ethanol production from sweet sorghum juice by Saccharomyces cerevisiae NP01 under very high gravity (VHG fermentation (280 g·L?1 of total sugar conditions. The supplemented DSY and DSYH concentrations were 11, 16 and 21 g·L?1, corresponding to a yeast extract nitrogen content of 6, 9 and 12 g·L?1, respectively. The initial yeast cell concentration for ethanol fermentation was approximately 5 × 107 cells·mL?1. The fermentation was carried out in single batch mode at 30 °C in 1-L air-locked bottles with an agitation rate of 100 rpm. Ethanol production from the juice with and without yeast extract (9 g·L?1 was also performed as control treatments. The results showed that DSY at 21 g·L?1gave the highest ethanol concentration (PE, 107 g·L?1 and yield (Yp/s, 0.47 g·g?1. The use of DSYH at the same DSY concentration improved ethanol productivity (Qp, but not PE and Yp/s. The ethanol production efficiencies of the juice under DSY and DSYH supplementations were markedly higher than those without nutrient supplementation. However, the PE and Qp values of the juice containing 21 g·L?1 of DSY was approximately 7 g·L?1 and 0.62 g·L?1·h?1 lower than those under the presence of yeast extract (9 g·L?1, respectively. At the end of the single batch fermentation under the optimum DSY concentration, the sugar consumption was approximately 80%. Therefore in the repeated-batch fermentation, the initial total sugar was reduced to 240 g·L?1. The results showed that the system could be carried out at least 20 successive batches with the average PE, Yp/s and Qp of 95 g·L?1, 0.46 g·g?1 and 1.45 g·L?1·h?1, respectively.

Pattana Laopaiboon

2013-03-01

32

Comparison of methods for detoxification of spruce hydrolysate for bacterial cellulose production  

OpenAIRE

BACKGROUND: Bacterial cellulose (BC) is a nanostructured material with unique properties and wide applicability. In order to decrease the production cost of bacterial cellulose, lignocellulose-based media have considerable potential as alternative cost-effective feedstocks. However, pretreatment and enzymatic hydrolysis of lignocellulose to sugars also generate fermentation inhibitors. Detoxification of lignocellulosic hydrolysates is needed to achieve efficient production of BC. In this inve...

Guo, Xiang; Cavka, Adnan; Jo?nsson, Leif J.; Hong, Feng

2013-01-01

33

Metabolic Pathways and Biofuel Production from Lignocellulosic Biomass by Thermophilic Anaerobes isolated from Icelandic Hot Springs  

OpenAIRE

The present investigation is, firstly, a literature review of most current studies on biofuel production (e.g. ethanol, hydrogen and methane) from lignocellulosic biomass and the use of the isolated thermophilic anaerobic strains from Icelandic hot springs in the process. Various factors affect the production of biofuels from lignocellulosic biomass including partial pressure of hydrogen, initial concentration of lignocellulosic hydrolysates, acidity and alkalinity of pretreatment, inhibitor...

Sara Lind Jónsdóttir 1989

2014-01-01

34

Grass Lignocellulose  

Science.gov (United States)

Grass lignocelluloses are limited in bioconversion by aromatic constituents, which include both lignins and phenolic acids esters. Histochemistry, ultraviolet absorption microspectrophotometry, and response to microorganisms and specific enzymes have been used to determine the significance of aromatics toward recalcitrance. Coniferyl lignin appears to be the most effective limitation to biodegradation, existing in xylem cells of vascular tissues; cell walls with syringyl lignin, for example, leaf sclerenchyma, are less recalcitrant. Esterified phenolic acids, i.e., ferulic and p-coumaric acids, often constitute a major chemical limitation in nonlignified cell walls to biodegradation in grasses, especially warm-season species. Methods to improve biodegradability through modification of aromatics include: plant breeding, use of lignin-degrading white-rot fungi, and addition of esterases. Plant breeding for new cultivars has been especially effective for nutritionally improved forages, for example, bermudagrasses. In laboratory studies, selective white-rot fungi that lack cellulases delignified the lignocellulosic materials and improved fermentation of residual carbohydrates. Phenolic acid esterases released p-coumaric and ferulic acids for potential coproducts, improved the available sugars for fermentation, and improved biodegradation. The separation and removal of the aromatic components for coproducts, while enhancing the availability of sugars for bioconversion, could improve the economics of bioconversion.

Akin, Danny E.

35

Bioconversion of lignocellulosic residues by Agrocybe cylindracea and Pleurotus ostreatus mushroom fungi--assessment of their effect on the final product and spent substrate properties.  

Science.gov (United States)

Nine agro-industrial and forestry by-products were subjected to solid-state fermentation by Agrocybe cylindracea and Pleurotus ostreatus, and the process and end-products were comparatively evaluated. Grape marc waste plus cotton gin trash was the best performing medium for both fungi, while substrate composition had a marked effect on most cultivation parameters. Biological efficiency was positively correlated with nitrogen, lignin and ash, and negatively with hemicelluloses and carbohydrate content of substrates. Spent substrates demonstrated high reductions in hemicelluloses and cellulose in contrast to lignin; fibre fractions were correlated with nitrogen, fat and ash content of initial materials, while residual mycelial biomass was affected by mushroom productivity. Mushroom proximate analysis revealed significant variations of constituents depending on the substrate. Crude protein and fat were correlated with substrates nitrogen for both species. Alternative cultivation substrates of high potential are proposed, while spent material could be exploited as animal feed due to its upgraded properties. PMID:24837930

Koutrotsios, Georgios; Mountzouris, Konstantinos C; Chatzipavlidis, Iordanis; Zervakis, Georgios I

2014-10-15

36

Selective suppression of bacterial contaminants by process conditions during lignocellulose based yeast fermentations  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Contamination of bacteria in large-scale yeast fermentations is a serious problem and a threat to the development of successful biofuel production plants. Huge research efforts have been spent in order to solve this problem, but additional ways must still be found to keep bacterial contaminants from thriving in these environments. The aim of this project was to develop process conditions that would inhibit bacterial growth while giving yeast a competitive advantage. Results Lactic acid bacteria are usually considered to be the most common contaminants in industrial yeast fermentations. Our observations support this view but also suggest that acetic acid bacteria, although not so numerous, could be a much more problematic obstacle to overcome. Acetic acid bacteria showed a capacity to drastically reduce the viability of yeast. In addition, they consumed the previously formed ethanol. Lactic acid bacteria did not show this detrimental effect on yeast viability. It was possible to combat both types of bacteria by a combined addition of NaCl and ethanol to the wood hydrolysate medium used. As a result of NaCl + ethanol additions the amount of viable bacteria decreased and yeast viability was enhanced concomitantly with an increase in ethanol concentration. The successful result obtained via addition of NaCl and ethanol was also confirmed in a real industrial ethanol production plant with its natural inherent yeast/bacterial community. Conclusions It is possible to reduce the number of bacteria and offer a selective advantage to yeast by a combined addition of NaCl and ethanol when cultivated in lignocellulosic medium such as wood hydrolysate. However, for optimal results, the concentrations of NaCl + ethanol must be adjusted to suit the challenges offered by each hydrolysate.

Albers Eva

2011-12-01

37

Detoxification of hemicellulosic hydrolysates from extracted olive pomace by diananofiltration  

OpenAIRE

Xylitol can be obtained from the pentose-rich hemicellulosic fraction of agricultural residues, such as extracted olive pomace, by fermentation. Dilute acid hydrolysis of lignocellulosic materials, produces the release of potential inhibitory compounds mainly furan derivatives, aliphatic acids, and phenolic compounds. In order to study the potential on the increase of the hydrolysate fermentability, detoxification experiments based on diananofiltration membrane separation processes were made....

Bra?¡s, Teresa; Guerra, Vera; Torrado, Ivone; Lourena?§o, Pedro; Carvalheiro, Florbela; Duarte, Lua?­s C.; Neves, Luisa A.

2014-01-01

38

Electricity generation by microbial fuel cells fuelled with wheat straw hydrolysate  

International Nuclear Information System (INIS)

Electricity production from microbial fuel cells fueled with hydrolysate produced by hydrothermal treatment of wheat straw can achieve both energy production and domestic wastewater purification. The hydrolysate contained mainly xylan, carboxylic acids, and phenolic compounds. Power generation and substrate utilization from the hydrolysate was compared with the ones obtained by defined synthetic substrates. The power density increased from 47 mW m?2 to 148 mW m?2 with the hydrolysate:wastewater ratio (RHW in m3 m?3) increasing from 0 to 0.06 (corresponding to 0–0.7 g dm?3 of carbohydrates). The power density with the hydrolysate was higher than the one with only xylan (120 mW m?2) and carboxylic acids as fuel. The higher power density can be caused by the presence of phenolic compounds in the hydrolysates, which could mediate electron transport. Electricity generation with the hydrolysate resulted in 95% degradation of the xylan and glucan. The study demonstrates that lignocellulosic hydrolysate can be used for co-treatment with domestic wastewater for power generation in microbial fuel cells. -- Highlights: ? Electricity production in microbial fuel cells. ? Hydrolysate from hydrothermal treated wheat straw as fuel. ? Larger electricity production than with simple compounds as fuel. ? No need for detoxification and nutrients to the hydrolysate. ? Effective (95%) microbial utilization of the polymeric carbohydrates.

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A comparative study of the hydrolysis of gamma irradiated lignocelluloses  

Directory of Open Access Journals (Sweden)

Full Text Available The effect of high-dose irradiation as a pretreatment method on two common lignocellulosic materials; hardwood (Khaya senegalensis and softwood (Triplochiton scleroxylon were investigated by assessing the potential of cellulase enzyme derived from Aspergillus flavus Linn isolate NSPR 101 to hydrolyse the materials. The irradiation strongly affected the materials, causing the enzymatic hydrolysis to increase by more than 3 fold. Maximum digestibility occurred in softwood at 40kGy dosage of irradiation, while in hardwood it was at 90kGy dosage. The results also showed that, at the same dosage levels (p < 0.05, hardwood was hydrolysed significantly better compared to the softwood.

E. Betiku

2009-06-01

40

Exploring critical factors for fermentative hydrogen production from various types of lignocellulosic biomass  

OpenAIRE

Four dilute-acid pretreated and hydrolysed lignocellulosic raw materials were evaluated as substrates for fermentative hydrogen production by Caldicellulosiruptor saccharolyticus. Their fermentability was ranked in the order: barley straw > wheat straw > corn stalk > corn cob. The content of 5-hydroxymethylfurfural (HMF) in medium with hydrolysates prepared from corn cob (1.0 g/L) and corn stalk (0.8 g/L), respectively reached levels likely to be toxic for growth of C. saccharolyticus. HMF wa...

Panagiotopoulos, I.; Bakker, R.; Vrije, G. J.; Niel, E. W. J.; Koukios, E.; Claassen, P. A. M.

2011-01-01

41

A comparative study of the hydrolysis of gamma irradiated lignocelluloses  

OpenAIRE

The effect of high-dose irradiation as a pretreatment method on two common lignocellulosic materials; hardwood (Khaya senegalensis) and softwood (Triplochiton scleroxylon) were investigated by assessing the potential of cellulase enzyme derived from Aspergillus flavus Linn isolate NSPR 101 to hydrolyse the materials. The irradiation strongly affected the materials, causing the enzymatic hydrolysis to increase by more than 3 fold. Maximum digestibility occurred in softwood at 40kGy dosage of i...

Betiku, E.; Adetunji, O. A.; Ojumu, T. V.; Solomon, B. O.

2009-01-01

42

Glucose content in the liquid hydrolysate after dilute acid pretreatment is affected by the starch content in rice straw.  

Science.gov (United States)

Lignocellulosic biomass, such as rice straw, is often utilized as a bioresource after being hydrolyzed using dilute acid and separated into liquid hydrolysate and acid-insoluble residue. However, the biomass component that determines the distribution between liquid hydrolysate and acid-insoluble residue has not yet been clarified. In this study, the glucose content in the liquid hydrolysate and weight of acid-insoluble residue of 13 rice cultivars were analyzed. Starch content was positively correlated with glucose content in the liquid hydrolysate, and negatively correlated with acid-insoluble residue weight. These results indicate that the glucose in the liquid hydrolysate is mainly liberated from starch rather than cellulose in the rice straw. These observations suggest that starch content is a good indicator of the glucose distribution between the liquid hydrolysate and insoluble residue. PMID:24140898

Teramura, Hiroshi; Oshima, Tomoko; Matsuda, Fumio; Sasaki, Kengo; Ogino, Chiaki; Yamasaki, Masanori; Kondo, Akihiko

2013-12-01

43

Enzymatic conversion of lignocellulose into fermentable sugars : challenges and opportunities  

DEFF Research Database (Denmark)

The economic dependency on fossil fuels and the resulting effects on climate and environment have put tremendous focus on utilizing fermentable sugars from lignocellulose, the largest known renewable carbohydrate source. The fermentable sugars in lignocellulose are derived from cellulose and hemicelluloses but these are not readily accessible to enzymatic hydrolysis and require a pretreatment, which causes an extensive modification of the lignocellulosic structure. A number of pretreatment technologies are under development and being tested in pilot scale. Hydrolysis of lignocellulose carbohydrates into fermentable sugars requires a number of different cellulases and hemicellulases. The hydrolysis of cellulose is a sequential breakdown of the linear glucose chains, whereas hemicellulases must be capable of hydrolysing branched chains containing different sugars and functional groups. The technology for pretreatment and hydrolysis has been developed to an extent that is close to a commercially viable level. Ithas become possible to process lignocellulose at high substrate levels and the enzyme performance has been improved. Also the cost of enzymes has been reduced. Still a number of technical and scientific issues within pretreatment and hydrolysis remain to be solved. However, significant improvements in yield and cost reductions are expected, thus making large-scale fermentation of lignocellulosic substrates possible. © 2007 Society of Chemical Industry and John Wiley & Sons, Ltd

JØrgensen, Henning; Kristensen, Jan Bach

2007-01-01

44

Ethanol production from lignocellulose  

Science.gov (United States)

This invention presents a method of improving enzymatic degradation of lignocellulose, as in the production of ethanol from lignocellulosic material, through the use of ultrasonic treatment. The invention shows that ultrasonic treatment reduces cellulase requirements by 1/3 to 1/2. With the cost of enzymes being a major problem in the cost-effective production of ethanol from lignocellulosic material, this invention presents a significant improvement over presently available methods.

Ingram, Lonnie O. (Gainesville, FL); Wood, Brent E. (Gainesville, FL)

2001-01-01

45

Beneficial effect of corncob acid hydrolysate on the lipid production by oleaginous yeast Trichosporon dermatis.  

Science.gov (United States)

In this work, corncob acid hydrolysate and its simulated medium whose sugar composition was the same as the corncob acid hydrolysate were used as fermentation substrate for lipid production by oleaginous yeast Trichosporon dermatis. On the corncob acid hydrolysate, after 7 days of fermentation, the biomass, lipid content, lipid yield, and lipid coefficient of T. dermatis were 17.3 g/L, 40.2%, 7.0 g/L, and 16.5%, respectively. Interestingly, during the lipid fermentation on the corncob acid hydrolysate, glucose, xylose, arabinose, and even acetic acid could be well utilized as carbon sources by T. dermatis. Surprisingly, the lipid yield (7.0 g/L) of T. dermatis on the corncob acid hydrolysate was much higher than that (3.8 g/L) on the simulated medium, in spite of the fact that the lipid coefficient (17.4%) on the simulated medium was a little higher. This phenomenon further showed that lignocellulosic acid hydrolysate was a suitable substrate for lipid fermentation by T. dermatis. This work would help the comprehensive utilization of lignocellulosic biomass for lipid production. PMID:24840672

Xiong, Lian; Huang, Chao; Yang, Xiao-Yan; Lin, Xiao-Qing; Chen, Xue-Fang; Wang, Can; Wang, Bo; Zeng, Xin-An; Chen, Xin-De

2015-01-01

46

Novel bio-based catalytic strategies for the fractionation and valorization of lignocellulose  

OpenAIRE

Für das Ersetzen von fossilen Ressourcen werden in den kommenden Jahrzenten Verbund-Bioraffineriekonzepte notwendig. Diese Arbeit beschäftigt sich mit der Nutzung von Biomasse zur Herstellung biogener Kraftstoffe und Rohchemikalien. Zunächst wurde eine konzeptuelle Strategie zur Vorbehandlung von Lignocellulose, der 1 step OrganoCat Process vorgestellt und optimiert. Dieses zweiphasige Reaktionssystem beinhaltet eine wässrige, reaktive Phase mit Oxalsäure als Katalysator zur Hydrolyse de...

Grande, Philipp Michael

2014-01-01

47

Electricity generation by microbial fuel cells fuelled with wheat straw hydrolysate  

DEFF Research Database (Denmark)

Electricity production from microbial fuel cells fueled with hydrolysate produced by hydrothermal treatment of wheat straw can achieve both energy production and domestic wastewater purification. The hydrolysate contained mainly xylan, carboxylic acids, and phenolic compounds. Power generation and substrate utilization from the hydrolysate was compared with the ones obtained by defined synthetic substrates. The power density increased from 47 mW m?2 to 148 mW m?2 with the hydrolysate:wastewater ratio (RHW in m3 m?3) increasing from 0 to 0.06 (corresponding to 0–0.7 g dm?3 of carbohydrates). The power density with the hydrolysate was higher than the one with only xylan (120 mW m?2) and carboxylic acids as fuel. The higher power density can be caused by the presence of phenolic compounds in the hydrolysates, which could mediate electron transport. Electricity generation with the hydrolysate resulted in 95% degradation of the xylan and glucan. The study demonstrates that lignocellulosic hydrolysate can be used for co-treatment with domestic wastewater for power generation in microbial fuel cells.

Thygesen, Anders; Poulsen, Finn Willy

2011-01-01

48

Feasibility of filamentous fungi for biofuel production using hydrolysate from dilute sulfuric acid pretreatment of wheat straw  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Lipids produced from filamentous fungi show great promise for biofuel production, but a major limiting factor is the high production cost attributed to feedstock. Lignocellulosic biomass is a suitable feedstock for biofuel production due to its abundance and low value. However, very limited study has been performed on lipid production by culturing oleaginous fungi with lignocellulosic materials. Thus, identification of filamentous fungal strains capable of utilizing lignocellulosic hydrolysates for lipid accumulation is critical to improve the process and reduce the production cost. Results The growth performances of eleven filamentous fungi were investigated when cultured on glucose and xylose. Their dry cell weights, lipid contents and fatty acid profiles were determined. Six fungal strains with high lipid contents were selected to culture with the hydrolysate from dilute sulfuric acid pretreatment of wheat straw. The results showed that all the selected fungal strains were able to grow on both detoxified liquid hydrolysate (DLH and non-detoxified liquid hydrolysate (NDLH. The highest lipid content of 39.4% was obtained by Mortierella isabellina on NDLH. In addition, NDLH with some precipitate could help M. isabellina form pellets with an average diameter of 0.11?mm. Conclusion This study demonstrated the possibility of fungal lipid production from lignocellulosic biomass. M. isabellina was the best lipid producer grown on lignocellulosic hydrolysates among the tested filamentous fungi, because it could not only accumulate oils with a high content by directly utilizing NDLH to simplify the fermentation process, but also form proper pellets to benefit the downstream harvesting. Considering the yield and cost, fungal lipids from lignocellulosic biomass are promising alternative sources for biodiesel production.

Zheng Yubin

2012-07-01

49

Bioprocessing of bagasse hydrolysate for ethanol and xylitol production using thermotolerant yeast.  

Science.gov (United States)

Fermentation of xylose-rich and glucose-rich bagasse hydrolysates, obtained from the two-stage acid hydrolysis was studied using the thermotolerant yeast Kluyveromyces sp. IIPE453. The yeast could grow on xylose-rich hydrolysate at 50 °C with the dry cell weight, cell mass yield and maximum specific growth rate of 5.35 g l(-1), 0.58 g g(-1) and 0.13 h(-1), respectively. The yeast was found to be very promising for ethanol as well as xylitol production from the sugars obtained from the lignocellulosic biomass. Batch fermentations of xylose-rich and glucose-rich hydrolysates yielded 0.61 g g(-1) xylitol and 0.43 g g(-1) ethanol in the broth, respectively based on the sugars present in the hydrolysate. Overall ethanol yield of 165 g (210 ml) and 183 g xylitol per kg of bagasse was obtained, when bagasse hydrolysate was used as a substrate. Utilization of both the glucose and xylose sugars makes the process most economical by producing both ethanol and xylitol based on biorefinery concept. On validating the experimental data of ethanol fermentation, the modified Luong kinetic model for product inhibition as well as inhibition due to inhibitory compounds present in hydrolysate, the model was found to be the best fit for ethanol formation from bagasse hydrolysate using Kluyveromyces sp. IIPE453. PMID:25090978

Kumar, Sachin; Dheeran, Pratibha; Singh, Surendra P; Mishra, Indra M; Adhikari, Dilip K

2015-01-01

50

Sugar production from lignocellulosic materials by gamma photolysis  

International Nuclear Information System (INIS)

Lignocellulosic plant materials were treated with swelling agent and exposed to gamma radiation from Cobalt 60 or Cesium 137. The swelling agents include NaOH, KOH, NH4OH, Benzyle trimethyl ammonium hydroxide, ZnCl2, CaCO3, H3PO4, and H2SO4. At 50 Mrads or above the lignocellulosic materials were extensively solubilized and formed a thick paste or liquid, depending upon the amount of liquid used. The brownish dark hydrolysate had a sweet molasses like odor. Complete solubilization has been acheived for samples such as sugarcane bagasse, newspaper, cotton linter, cotton clothes, saw dust, and alpha cellulose powder. About 40% total sugar and 7% reducing sugar per dry weight of sugarcane bagasse was obtained. The majority of the soluble carbohydrate seemed to be disaccharides or larger molecules. Solubilization of cellulose was dosage dependent, and the rate was facilitated by alkali. However, the released sugar was further decomposed by the alkali

51

Ethanol production using a soy hydrolysate-based medium or a yeast autolysate-based medium  

Science.gov (United States)

This invention presents a method for the production of ethanol that utilizes a soy hydrolysate-based nutrient medium or a yeast autolysate-based medium nutrient medium in conjunction with ethanologenic bacteria and a fermentable sugar for the cost-effective production of ethanol from lignocellulosic biomass. The invention offers several advantages over presently available media for use in ethanol production, including consistent quality, lack of toxins and wide availability.

Ingram, Lonnie O. (Gainesville, FL)

2000-01-01

52

A mathematical model for the inhibitory effects of lignin in enzymatic hydrolysis of lignocellulosics.  

Science.gov (United States)

A new model for enzymatic hydrolysis of lignocellulosic biomass distinguishes causal influences from enzyme deactivation and restrictions on the accessibility of cellulose. It focuses on calculating the amount of unreacted cellulose at cessation of enzyme activity, unlike existing models that were constructed for calculating the time dependence of conversion. There are three adjustable parameters: (1) 'occluded cellulose' is defined as cellulose that cannot be hydrolysed regardless of enzyme loading or incubation time, (2) a 'characteristic enzyme loading' is sufficient to hydrolyse half of the non-occluded cellulose, (3) a 'mechanism index' measures deviations from first-order kinetics. This model was used to predict that the optimal incubation temperature is lower for lignocellulosics than for pure cellulose. For steam-exploded pine wood after 96h incubation, occluded cellulose was 24% and 26% at 30°C and 50°C, and the characteristic enzyme loadings were 10 and 18FPU/g substrate, respectively. PMID:23340076

Newman, Roger H; Vaidya, Alankar A; Campion, Sylke H

2013-02-01

53

Fungal delignification of lignocellulosic biomass improves the saccharification of cellulosics.  

Science.gov (United States)

The biological delignification of lignocellulosic feedstocks, Prosopis juliflora and Lantana camara was carried out with Pycnoporus cinnabarinus, a white rot fungus, at different scales under solid-state fermentation (SSF) and the fungal treated substrates were evaluated for their acid and enzymatic saccharification. The fungal fermentation at 10.0 g substrate level optimally delignified the P. juliflora by 11.89% and L. camara by 8.36%, and enriched their holocellulose content by 3.32 and 4.87%, respectively, after 15 days. The fungal delignification when scaled up from 10.0 g to 75.0, 200.0 and 500.0 g substrate level, the fungus degraded about 7.69-10.08% lignin in P. juliflora and 6.89-7.31% in L. camara, and eventually enhanced the holocellulose content by 2.90-3.97 and 4.25-4.61%, respectively. Furthermore, when the fungal fermented L. camara and P. juliflora was hydrolysed with dilute sulphuric acid, the sugar release was increased by 21.4-42.4% and the phenolics content in hydrolysate was decreased by 18.46 and 19.88%, as compared to the unfermented substrate acid hydrolysis, respectively. The reduction of phenolics in acid hydrolysates of fungal treated substrates decreased the amount of detoxifying material (activated charcoal) by 25.0-33.0% as compared to the amount required to reduce almost the same level of phenolics from unfermented substrate hydrolysates. Moreover, an increment of 21.1-25.1% sugar release was obtained when fungal treated substrates were enzymatically hydrolysed as compared to the hydrolysis of unfermented substrates. This study clearly shows that fungal delignification holds potential in utilizing plant residues for the production of sugars and biofuels. PMID:20711746

Gupta, Rishi; Mehta, Girija; Khasa, Yogender Pal; Kuhad, Ramesh Chander

2011-07-01

54

Ethanol production from wood hydrolysate using genetically engineered Zymomonas mobilis  

Energy Technology Data Exchange (ETDEWEB)

An ethanologenic microorganism capable of fermenting all of the sugars released from lignocellulosic biomass through a saccharification process is essential for secondary bioethanol production. We therefore genetically engineered the ethanologenic bacterium Zymomonas mobilis such that it efficiently produced bioethanol from the hydrolysate of wood biomass containing glucose, mannose, and xylose as major sugar components. This was accomplished by introducing genes encoding mannose and xylose catabolic enzymes from Escherichia coli. Integration of E. coli manA into Z. mobilis chromosomal DNA conferred the ability to co-ferment mannose and glucose, producing 91 % of the theoretical yield of ethanol within 36 h. Then, by introducing a recombinant plasmid harboring the genes encoding E. coli xylA, xylB, tal, and tktA, we broadened the range of fermentable sugar substrates for Z. mobilis to include mannose and xylose as well as glucose. The resultant strain was able to ferment a mixture of 20 g/l glucose, 20 g/l mannose, and 20 g/l xylose as major sugar components of wood hydrolysate within 72 h, producing 89.8 % of the theoretical yield. The recombinant Z. mobilis also efficiently fermented actual acid hydrolysate prepared from cellulosic feedstock containing glucose, mannose, and xylose. Moreover, a reactor packed with the strain continuously produced ethanol from acid hydrolysate of wood biomass from coniferous trees for 10 days without accumulation of residual sugars. Ethanol productivity was at 10.27 g/l h at a dilution rate of 0.25 h{sup -1}. (orig.)

Yanase, Hideshi; Miyawaki, Hitoshi; Sakurai, Mitsugu; Kawakami, Akinori; Matsumoto, Mari; Haga, Kenji; Kojima, Motoki; Okamoto, Kenji [Tottori Univ. (Japan). Dept. of Chemistry and Biotechnology

2012-06-15

55

Ethanol production from wood hydrolysate using genetically engineered Zymomonas mobilis.  

Science.gov (United States)

An ethanologenic microorganism capable of fermenting all of the sugars released from lignocellulosic biomass through a saccharification process is essential for secondary bioethanol production. We therefore genetically engineered the ethanologenic bacterium Zymomonas mobilis such that it efficiently produced bioethanol from the hydrolysate of wood biomass containing glucose, mannose, and xylose as major sugar components. This was accomplished by introducing genes encoding mannose and xylose catabolic enzymes from Escherichia coli. Integration of E. coli manA into Z. mobilis chromosomal DNA conferred the ability to co-ferment mannose and glucose, producing 91 % of the theoretical yield of ethanol within 36 h. Then, by introducing a recombinant plasmid harboring the genes encoding E. coli xylA, xylB, tal, and tktA, we broadened the range of fermentable sugar substrates for Z. mobilis to include mannose and xylose as well as glucose. The resultant strain was able to ferment a mixture of 20 g/l glucose, 20 g/l mannose, and 20 g/l xylose as major sugar components of wood hydrolysate within 72 h, producing 89.8 % of the theoretical yield. The recombinant Z. mobilis also efficiently fermented actual acid hydrolysate prepared from cellulosic feedstock containing glucose, mannose, and xylose. Moreover, a reactor packed with the strain continuously produced ethanol from acid hydrolysate of wood biomass from coniferous trees for 10 days without accumulation of residual sugars. Ethanol productivity was at 10.27 g/l h at a dilution rate of 0.25 h(-1). PMID:22573268

Yanase, Hideshi; Miyawaki, Hitoshi; Sakurai, Mitsugu; Kawakami, Akinori; Matsumoto, Mari; Haga, Kenji; Kojima, Motoki; Okamoto, Kenji

2012-06-01

56

Complex Physiology and Compound Stress Responses during Fermentation of Alkali-Pretreated Corn Stover Hydrolysate by an Escherichia coli Ethanologen  

Science.gov (United States)

The physiology of ethanologenic Escherichia coli grown anaerobically in alkali-pretreated plant hydrolysates is complex and not well studied. To gain insight into how E. coli responds to such hydrolysates, we studied an E. coli K-12 ethanologen fermenting a hydrolysate prepared from corn stover pretreated by ammonia fiber expansion. Despite the high sugar content (?6% glucose, 3% xylose) and relatively low toxicity of this hydrolysate, E. coli ceased growth long before glucose was depleted. Nevertheless, the cells remained metabolically active and continued conversion of glucose to ethanol until all glucose was consumed. Gene expression profiling revealed complex and changing patterns of metabolic physiology and cellular stress responses during an exponential growth phase, a transition phase, and the glycolytically active stationary phase. During the exponential and transition phases, high cell maintenance and stress response costs were mitigated, in part, by free amino acids available in the hydrolysate. However, after the majority of amino acids were depleted, the cells entered stationary phase, and ATP derived from glucose fermentation was consumed entirely by the demands of cell maintenance in the hydrolysate. Comparative gene expression profiling and metabolic modeling of the ethanologen suggested that the high energetic cost of mitigating osmotic, lignotoxin, and ethanol stress collectively limits growth, sugar utilization rates, and ethanol yields in alkali-pretreated lignocellulosic hydrolysates. PMID:22389370

Schwalbach, Michael S.; Tremaine, Mary; Marner, Wesley D.; Zhang, Yaoping; Bothfeld, William; Higbee, Alan; Grass, Jeffrey A.; Cotten, Cameron; Reed, Jennifer L.; da Costa Sousa, Leonardo; Jin, Mingjie; Balan, Venkatesh; Ellinger, James; Dale, Bruce; Kiley, Patricia J.

2012-01-01

57

Lignocellulose biodegradation : fundamentals and applications  

OpenAIRE

Lignocelluloses are the building blocks of all plants and are ubiquitous to most regions of our planet. Their chemical properties make it a substrate of enormous biotechnological value. The basic chemistry of cellulose, hemicellulose, and lignin has a profound effect on lignocellulose tertiary architecture. These intricate associations constitute physical and chemical barriers to lignocellulose utilization and biodegradation in natural and man-made environments. Overcoming these barriers is t...

Malherbe, Stephanus; Cloete, T. E.

2002-01-01

58

Bioethanol production from Lignocellulosic biomass by a novel Kluyveromyces marxianus strain.  

Science.gov (United States)

The yeast Kluyveromyces marxianus is considered as a potential alternative to Saccharomyces cerevisiae in producing ethanol as a biofuel. In this study, we investigated the ethanol fermentation properties of novel K. marxianus strain DMB1, isolated from bagasse hydrolysates. This strain utilized sorbitol as well as various pentoses and hexoses as single carbon sources under aerobic conditions and produced ethanol from glucose in hydrolysates of the Japanese cedar at 42 °C. Reference strains K. marxianus NBRC1777 and S. cerevisiae BY4743 did not assimilate sorbitol or ferment lignocellulosic hydrolysates to ethanol at this temperature. Thus strain DMB1 appears to be optimal for producing bioethanol at high temperatures, and might provide a valuable means of increasing the efficiency of ethanol fermentation. PMID:23832346

Goshima, Tetsuya; Tsuji, Masaharu; Inoue, Hiroyuki; Yano, Shinichi; Hoshino, Tamotsu; Matsushika, Akinori

2013-01-01

59

The chemistry involved in the steam treatment of lignocellulosic materials  

Directory of Open Access Journals (Sweden)

Full Text Available Pretreatment of lignocellulosic materials is essential for bioconversion because of the various physical and chemical barriers that greatly inhibit their susceptibility to bioprocesses such as hydrolysis and fermentation. The aim of this article is to review some of the most important pretreatment methods developed to date to enhance the conversion of lignocellulosics. Steam explosion, which precludes the treatment of biomass with high-pressure steam under optimal conditions, is presented as the pretreatment method of choice and its mode of action on lignocellulosics is discussed. The optimal pretreatment conditions for a given plant biomass are defined as those in which the best substrate for hydrolysis is obtained with the least amount of soluble sugars lost to side reactions such as dehydration. Therefore, pretreatment optimization results from a compromise between two opposite trends because hemicellulose recovery in acid hydrolysates can only be maximized at lower pretreatment severities, whereas the development of substrate accessibility requires more drastic pretreatment conditions in which sugar losses are inevitable. To account for this heterogeneity, the importance of several process-oriented parameters is discussed in detail, such as the pretreatment temperature, residence time into the steam reactor, use of an acid catalyst, susceptibility of the pretreated biomass to bioconversion, and process design.

Luiz Pereira Ramos

2003-12-01

60

The chemistry involved in the steam treatment of lignocellulosic materials  

Scientific Electronic Library Online (English)

Full Text Available Pretreatment of lignocellulosic materials is essential for bioconversion because of the various physical and chemical barriers that greatly inhibit their susceptibility to bioprocesses such as hydrolysis and fermentation. The aim of this article is to review some of the most important pretreatment m [...] ethods developed to date to enhance the conversion of lignocellulosics. Steam explosion, which precludes the treatment of biomass with high-pressure steam under optimal conditions, is presented as the pretreatment method of choice and its mode of action on lignocellulosics is discussed. The optimal pretreatment conditions for a given plant biomass are defined as those in which the best substrate for hydrolysis is obtained with the least amount of soluble sugars lost to side reactions such as dehydration. Therefore, pretreatment optimization results from a compromise between two opposite trends because hemicellulose recovery in acid hydrolysates can only be maximized at lower pretreatment severities, whereas the development of substrate accessibility requires more drastic pretreatment conditions in which sugar losses are inevitable. To account for this heterogeneity, the importance of several process-oriented parameters is discussed in detail, such as the pretreatment temperature, residence time into the steam reactor, use of an acid catalyst, susceptibility of the pretreated biomass to bioconversion, and process design.

Luiz Pereira, Ramos.

2003-12-01

61

Biogas from lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

Grontmij AB has cooperated with the University of Boraas to evaluate the technological and economical possibilities for biogas production from substrates containing lignocellulose, such as forest residues, straw and paper. The state of knowledge regarding biogas production from cellulosic biomass has been summarized. The research in the field has been described, especially focusing on pretreatment methods and their results on increased gas yields. An investigation concerning commercially available pretreatment methods and the cost of these technologies has been performed. An economic evaluation of biogas production from lignocellulosic materials has provided answers to questions regarding the profitability of these processes. Pretreatment with steam explosion was economically evaluated for three feedstocks - wood, straw and paper - and a combination of steam explosion and addition of NaOH for paper. The presented costs pertain to costs for the pretreatment step as it, in this study, was assumed that the pretreatment would be added to an existing plant and the lignocellulosic substrates would be part of a co-digestion process. The results of the investigation indicate that it is difficult to provide a positive net result when comparing the cost of pretreatment versus the gas yield (value) for two of the feedstocks - forest residues and straw. This is mainly due to the high cost of the raw material. For forest residues the steam pretreatment cost exceeded the gas yield by over 50 %, mainly due to the high cost of the raw material. For straw, the production cost was similar to the value of the gas. Paper showed the best economic result. The gas yield (value) for paper exceeded the pretreatment cost by 15 %, which makes it interesting to study paper further.

Berglund Odhner, Peter; Schabbauer, Anna [Grontmij AB, Stockholm (Sweden); Sarvari Horvath, Ilona; Mohseni Kabir, Maryam [Hoegskolan i Boraas, Boraas (Sweden)

2012-01-15

62

Omega-3 fatty acid production from enzyme saccharified hemp hydrolysate using a novel marine thraustochytrid strain.  

Science.gov (United States)

In this work, a newly isolated marine thraustochytrid strain, Schizochytrium sp. DT3, was used for omega-3 fatty acid production by growing on lignocellulose biomass obtained from local hemp hurd (Cannabis sativa) biomass. Prior to enzymatic hydrolysis, hemp was pretreated with sodium hydroxide to open the biomass structure for the production of sugar hydrolysate. The thraustochytrid strain was able to grow on the sugar hydrolysate and accumulated polyunsaturated fatty acids (PUFAs). At the lowest carbon concentration of 2%, the PUFAs productivity was 71% in glucose and 59% in the sugars hydrolysate, as a percentage of total fatty acids. Saturated fatty acids (SFAs) levels were highest at about 49% of TFA using 6% glucose as the carbon source. SFAs of 41% were produced using 2% of SH. This study demonstrates that SH produced from lignocellulose biomass is a potentially useful carbon source for the production of omega-3 fatty acids in thraustochytrids, as demonstrated using the new strain, Schizochytrium sp. DT3. PMID:25497057

Gupta, Adarsha; Abraham, Reinu E; Barrow, Colin J; Puri, Munish

2015-05-01

63

Ethanol from lignocellulosic biomass  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish El etanol es un combustible líquido que debido a la experiencia de producción existente se ha convertido en una importante alternativa para sustituir el uso de gasolina. Es posible mezclarlo en diferentes proporciones con gasolina, los motores no requieren de mayores cambios para su empleo y para su [...] distribución es posible emplear la infraestructura existente para la gasolina. El uso de lignocelulosas como biomasa parece promisoria para la producción de etanol, aun cuando debería aun se analizado cuidadosamente con el propósito holístico que incluya todas la tecnologías actuales y sus posibles implicancias. En este artículo se revisa el conocimiento de las características y fuentes de biomasa de origen vegetal, como también el desarrollo, características y posibilidades de obtener etanol de fuentes lignocelulósicas. Abstract in english Ethanol is the liquid combustible that has become the most promising alternative substitute for gasoline because of the experience gained in its production, the possibility of mixing it with gasoline in different proportions, the possibility of using the existing gasoline distribution infrastructure [...] , and the fact that major changes in engines are not required for its use. Lignocelluloses offer great potential as a biomass source for ethanol production, although their use still requires in-depth analysis with an objective and holistic focus that includes present and future technologic implications. The present article reviews current knowledge about the characteristics and sources of vegetable biomass, as well as the development and possibilities for obtaining ethanol from lignocelluloses sources.

Diana, Abril; Alejandro, Abril.

2009-08-01

64

21 CFR 102.22 - Protein hydrolysates.  

Science.gov (United States)

...2010-04-01 false Protein hydrolysates. 102...ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES...Foods § 102.22 Protein hydrolysates. The...names. “Hydrolyzed casein” is also an example...whereas “hydrolyzed milk protein” is not an...

2010-04-01

65

Process Design and Economics for the Conversion of Lignocellulosic Biomass to Hydrocarbons: Dilute-Acid and Enzymatic Deconstruction of Biomass to Sugars and Catalytic Conversion of Sugars to Hydrocarbons  

Energy Technology Data Exchange (ETDEWEB)

This report describes one potential conversion process to hydrocarbon products by way of catalytic conversion of lignocellulosic-derived hydrolysate. This model leverages expertise established over time in biomass deconstruction and process integration research at NREL, while adding in new technology areas for sugar purification and catalysis. The overarching process design converts biomass to die die diesel- and naphtha-range fuels using dilute-acid pretreatment, enzymatic saccharification, purifications, and catalytic conversion focused on deoxygenating and oligomerizing biomass hydrolysates.

Davis, R.; Tao, L.; Scarlata, C.; Tan, E. C. D.; Ross, J.; Lukas, J.; Sexton, D.

2015-03-01

66

Oil production by oleaginous yeasts using the hydrolysate from pretreatment of wheat straw with dilute sulfuric acid.  

Science.gov (United States)

This paper explores the use of the hydrolysate from the dilute sulfuric acid pretreatment of wheat straw for microbial oil production. The resulting hydrolysate was composed of pentoses (24.3g/L) and hexoses (4.9 g/L), along with some other degradation products, such as acetic acid, furfural, and hydroxymethylfurfural (HMF). Five oleaginous yeast strains, Cryptococcus curvatus, Rhodotorula glutinis, Rhodosporidium toruloides, Lipomyces starkeyi, and Yarrowia lipolytica, were evaluated by using this hydrolysate as substrates. The results showed that all of these strains could use the detoxified hydrolysate to produce lipids while except R. toruloides non-detoxified hydrolysate could also be used for the growth of all of the selective yeast strains. C. curvatus showed the highest lipid concentrations in medium on both the detoxified (4.2g/L) and non-detoxified (5.8 g/L) hydrolysates. And the inhibitory effect studies on C. curvatus indicated HMF had insignificant impacts at a concentration of up to 3g/L while furfural inhibited cell growth and lipid content by 72.0% and 62.0% at 1g/L, respectively. Our work demonstrates that lipid production is a promising alternative to utilize hemicellulosic sugars obtained during pretreatment of lignocellulosic materials. PMID:21463940

Yu, Xiaochen; Zheng, Yubin; Dorgan, Kathleen M; Chen, Shulin

2011-05-01

67

Protein Hydrolysates/Peptides in Animal Nutrition  

Science.gov (United States)

The use of protein hydrolysates as an important nutrient for growth and maintenance has been increasing in animal nutrition. Although animal proteins and protein hydrolysates are widely used however, recently vegetable protein hydrolysates are gaining importance. This chapter reviews the use of protein hydrolysates developed by enzyme hydrolysis and by solid state fermentation process in animal nutrition especially for piglets and compares it with the standard products such as plasma and fishmeal.

McCalla, Jeff; Waugh, Terry; Lohry, Eric

68

Efficient production of 2,3-butanediol from corn stover hydrolysate by using a thermophilic Bacillus licheniformis strain.  

Science.gov (United States)

In this study, a thermophilic Bacillus licheniformis strain X10 was newly isolated for 2,3-butanediol (2,3-BD) production from lignocellulosic hydrolysate. Strain X10 could utilize glucose and xylose simultaneously without carbon catabolite repression. In addition, strain X10 possesses high tolerance to fermentation inhibitors including furfural, vanillin, formic acid, and acetic acid. In a fed-batch fermentation, 74.0g/L of 2,3-BD was obtained from corn stover hydrolysate, with a productivity of 2.1g/Lh and a yield of 94.6%. Thus, this thermophilic B. licheniformis strain is a candidate for the development of efficient industrial production of 2,3-BD from corn stover hydrolysate. PMID:25151068

Li, Lixiang; Li, Kun; Wang, Kai; Chen, Chao; Gao, Chao; Ma, Cuiqing; Xu, Ping

2014-10-01

69

Genetic engineering of Enterobacter asburiae strain JDR-1 for efficient D(--) lactic acid production from hemicellulose hydrolysate.  

Science.gov (United States)

In the dilute acid pretreatment of lignocellulose, xylose substituted with alpha-1,2-methylglucuronate is released as methylglucuronoxylose (MeGAX), which cannot be fermented by biocatalysts currently used to produce biofuels and chemicals. Enterobacter asburiae JDR-1, isolated from colonized wood, efficiently fermented both MeGAX and xylose in acid hydrolysates of sweetgum xylan. Deletion of pflB and als genes in this bacterium modified the native mixed acid fermentation pathways to one for homolactate production. The resulting strain, Enterobacter asburiae L1, completely utilized both xylose and MeGAX in a dilute acid hydrolysate of sweetgum xylan and produced lactate approximating 100% of the theoretical maximum yield. Enterobacter asburiae JDR-1 offers a platform to develop efficient biocatalysts for production of fuels and chemicals from hemicellulose hydrolysates of hardwood and agricultural residues. PMID:19504045

Bi, C; Zhang, X; Rice, J D; Ingram, L O; Preston, J F

2009-10-01

70

Synergistic effects of 2A-mediated polyproteins on the production of lignocellulose degradation enzymes in tobacco plants  

OpenAIRE

Cost-effective bioethanol production requires a supply of various low-cost enzymes that can hydrolyse lignocellulosic materials consisting of multiple polymers. Because plant-based enzyme expression systems offer low-cost and large-scale production, this study simultaneously expressed ?-glucosidase (BglB), xylanase (XylII), exoglucanase (E3), and endoglucanase (Cel5A) in tobacco plants, which were individually fused with chloroplast-targeting transit peptides and linked via the 2A self-cleav...

Lee, Dae-seok; Lee, Kwang-ho; Jung, Sera; Jo, Eun-jin; Han, Kyung-hwan; Bae, Hyeun-jong

2012-01-01

71

LIGNOCELLULOSE NANOCOMPOSITE CONTAINING COPPER SULFIDE  

OpenAIRE

Copper sulfide-containing lignocellulose nanocomposites with improved electroconductivity were obtained. Two methods for preparing the copper sulfide lignocellulose nanocomposites were developed. An optimization of the parameters for obtaining of the nanocomposites with respect to obtaining improved electroconductivity, economy, and lower quantities and concentration of copper and sulfur ions in waste waters was conducted. The mechanisms and schemes of delaying and subsequent connection of co...

Sanchi Nenkova; Peter Velev; Mirela Dragnevska; Diyana Nikolova; Kiril Dimitrov

2011-01-01

72

Methods for degrading lignocellulosic materials  

Science.gov (United States)

The present invention relates to methods for degrading a lignocellulosic material, comprising: treating the lignocellulosic material with an effective amount of one or more cellulolytic enzymes in the presence of at least one surfactant selected from the group consisting of a secondary alcohol ethoxylate, fatty alcohol ethoxylate, nonylphenol ethoxylate, tridecyl ethoxylate, and polyoxyethylene ether, wherein the presence of the surfactant increases the degradation of lignocellulosic material compared to the absence of the surfactant. The present invention also relates to methods for producing an organic substance, comprising: (a) saccharifying a lignocellulosic material with an effective amount of one or more cellulolytic enzymes in the presence of at least one surfactant selected from the group consisting of a secondary alcohol ethoxylate, fatty alcohol ethoxylate, nonylphenol ethoxylate, tridecyl ethoxylate, and polyoxyethylene ether, wherein the presence of the surfactant increases the degradation of lignocellulosic material compared to the absence of the surfactant; (b) fermenting the saccharified lignocellulosic material of step (a) with one or more fermenting microorganisms; and (c) recovering the organic substance from the fermentation.

Vlasenko, Elena (Davis, CA); Cherry, Joel (Davis, CA); Xu, Feng (Davis, CA)

2011-05-17

73

Bioconversion of corncob acid hydrolysate into microbial oil by the oleaginous yeast Lipomyces starkeyi.  

Science.gov (United States)

For the first time, corncob acid hydrolysate was used for microbial oil production by the oleaginous yeast Lipomyces starkeyi. After hydrolysis by dilute sulfuric acid, corncob could turn into an acid hydrolysate with a sugar concentration of about 42.3 g/L. Detoxified by overliming and absorption with activated carbon, the corncob hydrolysate could be used by L. starkeyi efficiently that a total biomass of 17.2 g/L with a lipid content of 47.0 % (corresponding to a lipid yield of 8.1 g/L) and a lipid coefficient of 20.9 could be obtained after cultivation on the corncob hydrolysate for 8 days. Therefore, L. starkeyi is a promising strain for microbial oil production from lignocellulosic biomass. Glucose and xylose were used by L. starkeyi simultaneously during lipid fermentation while arabinose could not be utilized by it. Besides, the lipid composition of L. starkeyi was similar to that of vegetable oils; thus, it is a promising feedstock for biodiesel production. PMID:24343368

Huang, Chao; Chen, Xue-Fang; Yang, Xiao-Yan; Xiong, Lian; Lin, Xiao-Qing; Yang, Juan; Wang, Bo; Chen, Xin-De

2014-02-01

74

Sugar cane bagasse as feedstock for second generation ethanol production: Part II: Hemicellulose hydrolysate fermentability  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Sugar cane bagasse is produced in Brazil as waste of the sugar and ethanol industries. This lignocellulosic material is a potential source for second-generation ethanol production; however a pretreatment stage is essential, which aims at removing the hemicellulose component by disorganizing the lign [...] ocellulosic complex. In this work sugar cane bagasse was pretreated by diluted acid hydrolysis resulting in xylose-rich hydrolysates, which could be fermented to ethanol by a strain of the yeast Pichia stipitis. Statistical approach was used to investigate the effects of factors associated with the diluted acid hydrolysis process (acid concentration, solid:liquid ratio and time of exposure) on the fermentability of different hydrolysates. The statistical analysis was useful for determining the effects of the individual factors and their interactions on the response variables. An acid concentration of 1.09% (v/v), a solid:liquid ratio of 1:2.8 (g:ml), and an exposure time of 27 min were established and validated as the optimum pretreatment conditions for ethanol production from hemicellulose hydrolysates of sugar cane bagasse. Under these conditions, a hydrolysate with 50 g/l of xylose, 6.04 g/l of acetic acid, 0.55 g/l of hydroxylmethylfurfural and 0.09 g/l of furfural was obtained and its fermentation yielded roughly 20 g/l of ethanol in 40 hrs.

Gabriel J. Vargas, Betancur; Nei, Pereira Jr.

2010-09-15

75

High solids enzymatic hydrolysis of pretreated lignocellulosic materials with a powerful stirrer concept.  

Science.gov (United States)

In this study, we present a powerful stirred tank reactor system that can efficiently hydrolyse lignocellulosic material at high solid content to produce hydrolysates with glucose concentration > 100 g/kg. As lignocellulosic substrates alkaline-pretreated wheat straw and organosolv-pretreated beech wood were used. The developed vertical reactor was equipped with a segmented helical stirrer, which was specially designed for high biomass hydrolysis. The stirrer was characterised according to mixing behaviour and power input. To minimise the cellulase dosage, a response surface plan was used. With the empirical relationship between glucose yield, cellulase loading and solid content, the minimal cellulase dosage was calculated to reach at least 70% yield at high glucose and high substrate concentrations within 48 h. The optimisation resulted in a minimal enzyme dosage of 30 FPU/g dry matter (DM) for the hydrolysis of wheat straw and 20 FPU/g DM for the hydrolysis of beech wood. By transferring the hydrolysis reaction from shaking flasks to the stirred tank reactor, the glucose yields could be increased. Using the developed stirred tank reactor system, alkaline-pretreated wheat straw could be converted to 110 g/kg glucose (76%) at a solid content of 20% (w/w) after 48 h. Organosolv-pretreated beech wood could be efficiently hydrolysed even at 30% (w/w) DM, giving 150 g/kg glucose (72%). PMID:24242162

Ludwig, Daniel; Michael, Buchmann; Hirth, Thomas; Rupp, Steffen; Zibek, Susanne

2014-02-01

76

Production of Bioethanol From Lignocellulosic Biomass Using Thermophilic Anaerobic Bacteria  

DEFF Research Database (Denmark)

Bioethanol (ethanol produced from biomass) as a motor fuel is an attractive renewable fully sustainable energy sources as a means of lowering dependence on fossil fuels and air pollution towards greenhouse gasses, particularly CO2. Bioethanol, unlike gasoline, is an oxygenated fuel, which burns cleaner and thus lowers emissions of CO, NOx and unburned hydrocarbons pollutants, which are constituents in ground level ozone and particulate matter pollution (smog). In addition, bioethanol can replace currently used gasoline octane booster MTBE (methyl tertiary butyl ether), which causes serious environment and public health problems. Increasing demand of bioethanol for transportation sector and higher bioethanol prices than gasoline require utilization of cheap and unlimited raw materials in order to become bioethanol economically competitive with gasoline. Such alternative raw materials are residual lignocellulose (wastes) created from forest industries or from agricultural food crops (wheat straw, corn stover, rice straw). The lignocellulose contains lignin, which binds carbohydrate polymers (cellulose and hemicellulose) forming together a rather resistant structure. In this regards, a pre-treatment step is required in order to separate the lignin from polysaccharides. Once separated, the cellulose and hemicellulose fibres must be hydrolysed to monomeric sugars by enzymatic hydrolysis or dilute acid hydrolysis before being converted into ethanol. However, during the pretreatment and hydrolysis steps, various inhibitors towards microbial fermentation are generated along with the monomeric sugars. The inhibitors can be removed by various detoxification methods but the inclusion of this extra process step increases significantly the ethanol production cost. Compared with glucose, which can be readily fermented to ethanol by yeast strains such as Saccharomyces cerevisiae and bacterial strains of Zymomonas mobilis, xylose is more difficult to ferment because of a lack of industrially suitable microorganism able to rapidly and efficiently produce high concentrations of ethanol from xylose. In order to keep ethanol production cost at a minimum, the major sugars in lignocellulosic biomass (glucose and xylose) must be converted into ethanol due to high raw material cost, typically about 40% of the total ethanol production cost. The need for a microorganism able to utilize both glucose and xylose and to tolerate the inhibitory compounds present in lignocellulosic hydrolysates is therefore apparent. Several thermophilic anaerobic xylan degrading bacteria from our culture collection (EMB group at BioCentrum-DTU) have been screened for a potential ethanol producer from hemicellulose hydrolysates, and out of the screening test, one particular strain (A10) was selected for the best performance. The strain was morphologically and physiologically characterized as Thermoanaerobacter mathranii strain A10. Unlike other thermophilic anaerobic bacteria, the wild-type strain Thermoanaerobacter mathranii A10 was able to tolerate exogenously added ethanol of 5% (v/v) at 70oC in batch fermentation. To verify the potential of thermophilic anaerobe as an alternative ethanol producer from lignocellulose, ethanol tolerance and fermentation performance of lactate dehydrogenase deficient mutant strain Thermoanaerobacter BG1L1 was further studied. The experiments were carried out in a continuous immobilized reactor system (a fluidized bed reactor), which is likely to be the process design configuration for xylose fermentation in a Danish biorefinery concept for production of fuel ethanol. The immobilization of the fermenting organism inside the reactor and a long-term strain adaptation to high ethanol concentrations enhance significantly organism tolerance to ethanol (>8.3% v/v) and improve its fermentation capability when exposed at 5% (v/v) ethanol required in practice. The use of this reactor system enables high xylose conversion, effective glucose/xylose co-fermentation, and ethanol productivity of 1 g/l/h required for an economically viable bioethanol

Georgieva, Tania I.

2006-01-01

77

Thermophilic lignocellulose deconstruction.  

Science.gov (United States)

Thermophilic microorganisms are attractive candidates for conversion of lignocellulose to biofuels because they produce robust, effective, carbohydrate-degrading enzymes and survive under harsh bioprocessing conditions that reflect their natural biotopes. However, no naturally occurring thermophile is known that can convert plant biomass into a liquid biofuel at rates, yields and titers that meet current bioprocessing and economic targets. Meeting those targets requires either metabolically engineering solventogenic thermophiles with additional biomass-deconstruction enzymes or engineering plant biomass degraders to produce a liquid biofuel. Thermostable enzymes from microorganisms isolated from diverse environments can serve as genetic reservoirs for both efforts. Because of the sheer number of enzymes that are required to hydrolyze plant biomass to fermentable oligosaccharides, the latter strategy appears to be the preferred route and thus has received the most attention to date. Thermophilic plant biomass degraders fall into one of two categories: cellulosomal (i.e. multienzyme complexes) and noncellulosomal (i.e. 'free' enzyme systems). Plant-biomass-deconstructing thermophilic bacteria from the genera Clostridium (cellulosomal) and Caldicellulosiruptor (noncellulosomal), which have potential as metabolic engineering platforms for producing biofuels, are compared and contrasted from a systems biology perspective. PMID:24118059

Blumer-Schuette, Sara E; Brown, Steven D; Sander, Kyle B; Bayer, Edward A; Kataeva, Irina; Zurawski, Jeffrey V; Conway, Jonathan M; Adams, Michael W W; Kelly, Robert M

2014-05-01

78

Thermotolerant Yeasts for Bioethanol Production Using Lignocellulosic Substrates  

Science.gov (United States)

No other sustainable option for production of transportation fuels can match ethanol made from lignocellulosic biomass with respect to its dramatic environmental, economic, strategic and infrastructure advantages. Substantial progress has been made in advancing biomass ethanol (bioethanol) production technology to the point that it now has commercial potential, and several firms are engaged in the demanding task of introducing first-of-a-kind technology into the marketplace to make bioethanol a reality in existing fuel-blending markets. In order to lower pollution India has a long-term goal to use biofuels (bioethanol and biodiesel). Ethanol may be used either in pure form, or as a blend in petrol in different proportions. Since the cost of raw materials, which can account up to 50 % of the total production cost, is one of the most significant factors affecting the economy of alcohol, nowadays efforts are more concentrated on using cheap and abundant raw materials. Several forms of biomass resources exist (starch or sugar crops, weeds, oil plants, agricultural, forestry and municipal wastes) but of all biomass cellulosic resources represent the most abundant global source. The lignocellulosic materials include agricultural residues, municipal solid wastes (MSW), pulp mill refuse, switchgrass and lawn, garden wastes. Lignocellulosic materials contain two types of polysaccharides, cellulose and hemicellulose, bound together by a third component lignin. The principal elements of the lignocellulosic research include: i) evaluation and characterization of the waste feedstock; ii) pretreatment including initial clean up or dewatering of the feedstock; and iii) development of effective direct conversion bioprocessing to generate ethanol as an end product. Pre-treatment of lignocellulosic materials is a step in which some of the hemicellulose dissolves in water, either as monomeric sugars or as oligomers and polymers. The cellulose cannot be enzymatically hydrolyzed to glucose without a physical and chemical pre-treatment. The pre-treatment processes normally applied on the different substrates are acidic hydrolysis, steam explosion and wet oxidation. A problem for most pretreatment methods is the generation of compounds that are inhibitory towards the fermenting microorganisms, primarily phenols. Degradation products that could have inhibitory action in later fermentation steps are avoided during pre-treatment by wet oxidation. Followed by pre treatment, hydrolysed with enzymes known as cellulases and hemicellulases, which hydrolyse cellulose and hemicellulose respectively. The production of bioethanol requires two steps, fermentation and distillation. Practically all ethanol fermentation is still based on Saccharomyces cerevisiae . The fermentation using thermotolerant yeasts has more advantageous in that they have faster fermentation rates, avoid the cooling costs, and decrease the over all fermentation costs, so that ethanol can be made available at cheaper rates. In addition they can be used for efficient simultaneous saccharification and fermentation of cellulose by cellulases because the temperature optimum of cellulase enzymes (about 40 ° C to 45 ° C) is close to the fermentation temperature of thermotolerant yeasts. Hence selection and improvement of thermotolerant yeasts for bioconversion of lignocellulosic substrates is very useful.

Pasha, Chand; Rao, L. Venkateswar

79

Lignosulfonate and elevated pH can enhance enzymatic saccharification of lignocelluloses  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Nonspecific (nonproductive binding (adsorption of cellulase by lignin has been identified as a key barrier to reduce cellulase loading for economical sugar and biofuel production from lignocellulosic biomass. Sulfite Pretreatment to Overcome Recalcitrance of Lignocelluloses (SPORL is a relatively new process, but demonstrated robust performance for sugar and biofuel production from woody biomass especially softwoods in terms of yields and energy efficiencies. This study demonstrated the role of lignin sulfonation in enhancing enzymatic saccharification of lignocelluloses – lignosulfonate from SPORL can improve enzymatic hydrolysis of lignocelluloses, contrary to the conventional belief that lignin inhibits enzymatic hydrolysis due to nonspecific binding of cellulase. Results The study found that lignosulfonate from SPORL pretreatment and from a commercial source inhibits enzymatic hydrolysis of pure cellulosic substrates at low concentrations due to nonspecific binding of cellulase. Surprisingly, the reduction in enzymatic saccharification efficiency of a lignocellulosic substrate was fully recovered as the concentrations of these two lignosulfonates increased. We hypothesize that lignosulfonate serves as a surfactant to enhance enzymatic hydrolysis at higher concentrations and that this enhancement offsets its inhibitive effect from nonspecific binding of cellulase, when lignosulfonate is applied to lignocellulosic solid substrates. Lignosulfonate can block nonspecific binding of cellulase by bound lignin on the solid substrates, in the same manner as a nonionic surfactant, to significantly enhance enzymatic saccharification. This enhancement is linearly proportional to the amount of lignosulfonate applied which is very important to practical applications. For a SPORL-pretreated lodgepole pine solid, 90% cellulose saccharification was achieved at cellulase loading of 13 FPU/g glucan with the application of its corresponding pretreatment hydrolysate coupled with increasing hydrolysis pH to above 5.5 compared with only 51% for the control run without lignosulfonate at pH 5.0. The pH-induced lignin surface modification at pH 5.5 further reduced nonspecific binding of cellulase by lignosulfonate. Conclusions The results reported in this study suggest significant advantages for SPORL-pretreatment in terms of reducing water usage and enzyme dosage, and simplifying process integration, i.e., it should eliminate washing of SPORL solid fraction for direct simultaneous enzymatic saccharification and combined fermentation of enzymatic and pretreatment hydrolysates (SSCombF. Elevated pH 5.5 or higher, rather than the commonly believed optimal and widely practiced pH 4.8-5.0, should be used in conducting enzymatic saccharification of lignocelluloses.

Wang ZJ

2013-01-01

80

Industrial robust yeast isolates with great potential for fermentation of lignocellulosic biomass.  

Science.gov (United States)

The search of robust microorganisms is essential to design sustainable processes of second generation bioethanol. Yeast strains isolated from industrial environments are generally recognised to present an increased stress tolerance but no specific information is available on their tolerance towards inhibitors that come from the pretreatment of lignocellulosic materials. In this work, a strategy for the selection of different yeasts using hydrothermal hydrolysate from Eucalyptus globulus wood, containing different concentrations of inhibitors, was developed. Ten Saccharomyces cerevisiae and four Kluyveromyces marxianus strains isolated from industrial environments and four laboratory background strains were evaluated. Interestingly, a correlation between final ethanol titer and percentage of furfural detoxification was observed. The results presented here highlight industrial distillery environments as a remarkable source of efficient yeast strains for lignocellulosic fermentation processes. Selected strains were able to resourcefully degrade furfural and HMF inhibitors, producing 0.8g ethanol/Lh corresponding to 94% of the theoretical yield. PMID:24704884

Pereira, Francisco B; Romaní, Aloia; Ruiz, Héctor A; Teixeira, José A; Domingues, Lucília

2014-06-01

81

Pretreatment of lignocellulosic wastes to improve ethanol and biogas production: a review.  

Science.gov (United States)

Lignocelluloses are often a major or sometimes the sole components of different waste streams from various industries, forestry, agriculture and municipalities. Hydrolysis of these materials is the first step for either digestion to biogas (methane) or fermentation to ethanol. However, enzymatic hydrolysis of lignocelluloses with no pretreatment is usually not so effective because of high stability of the materials to enzymatic or bacterial attacks. The present work is dedicated to reviewing the methods that have been studied for pretreatment of lignocellulosic wastes for conversion to ethanol or biogas. Effective parameters in pretreatment of lignocelluloses, such as crystallinity, accessible surface area, and protection by lignin and hemicellulose are described first. Then, several pretreatment methods are discussed and their effects on improvement in ethanol and/or biogas production are described. They include milling, irradiation, microwave, steam explosion, ammonia fiber explosion (AFEX), supercritical CO(2) and its explosion, alkaline hydrolysis, liquid hot-water pretreatment, organosolv processes, wet oxidation, ozonolysis, dilute-and concentrated-acid hydrolyses, and biological pretreatments. PMID:19325822

Taherzadeh, Mohammad J; Karimi, Keikhosro

2008-09-01

82

Pretreatment of Lignocellulosic Wastes to Improve Ethanol and Biogas Production: A Review  

Science.gov (United States)

Lignocelluloses are often a major or sometimes the sole components of different waste streams from various industries, forestry, agriculture and municipalities. Hydrolysis of these materials is the first step for either digestion to biogas (methane) or fermentation to ethanol. However, enzymatic hydrolysis of lignocelluloses with no pretreatment is usually not so effective because of high stability of the materials to enzymatic or bacterial attacks. The present work is dedicated to reviewing the methods that have been studied for pretreatment of lignocellulosic wastes for conversion to ethanol or biogas. Effective parameters in pretreatment of lignocelluloses, such as crystallinity, accessible surface area, and protection by lignin and hemicellulose are described first. Then, several pretreatment methods are discussed and their effects on improvement in ethanol and/or biogas production are described. They include milling, irradiation, microwave, steam explosion, ammonia fiber explosion (AFEX), supercritical CO2 and its explosion, alkaline hydrolysis, liquid hot-water pretreatment, organosolv processes, wet oxidation, ozonolysis, dilute-and concentrated-acid hydrolyses, and biological pretreatments. PMID:19325822

Taherzadeh, Mohammad J.; Karimi, Keikhosro

2008-01-01

83

Pretreatment of Lignocellulosic Wastes to Improve Ethanol and Biogas Production: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available Lignocelluloses are often a major or sometimes the sole components of different waste streams from various industries, forestry, agriculture and municipalities. Hydrolysis of these materials is the first step for either digestion to biogas (methane or fermentation to ethanol. However, enzymatic hydrolysis of lignocelluloses with no pretreatment is usually not so effective because of high stability of the materials to enzymatic or bacterial attacks. The present work is dedicated to reviewing the methods that have been studied for pretreatment of lignocellulosic wastes for conversion to ethanol or biogas. Effective parameters in pretreatment of lignocelluloses, such as crystallinity, accessible surface area, and protection by lignin and hemicellulose are described first. Then, several pretreatment methods are discussed and their effects on improvement in ethanol and/or biogas production are described. They include milling, irradiation, microwave, steam explosion, ammonia fiber explosion (AFEX, supercritical CO2 and its explosion, alkaline hydrolysis, liquid hot-water pretreatment, organosolv processes, wet oxidation, ozonolysis, dilute- and concentrated-acid hydrolyses, and biological pretreatments.

Keikhosro Karimi

2008-09-01

84

New process to degrade lignocellulose  

International Nuclear Information System (INIS)

Researchers at ARS' Southern Regional Research Center, New Orleans are developing a new process to degrade lignocellulose. The lignocellulosic material is treated with three parts (weight to volume) of a swelling agent such as sodium hydroxide, then subjected to gamma irradiation from cesium-137, a nuclear waste material, at dosage levels up to 50 Mrad. The resulting material is a dark, brownish liquid, containing a variety of sugars and small fragments of lignin degradation products. The sugar solution is sterile and ready to use for fermentation or other aseptic processes

85

Hemicellulase production by Aspergillus niger DSM 26641 in hydrothermal palm oil empty fruit bunch hydrolysate and transcriptome analysis.  

Science.gov (United States)

Palm oil empty fruit bunches (EFB) is an abundant and cheap lignocellulose material in Southeast Asia. Its use as the sole medium for producing lignocellulose-hydrolyzing enzymes would increase its commercial value. A newly isolated Aspergillus niger DSM 26641 was investigated for its capability of producing hemicellulases in EFB hydrolysate obtained by treatment with pressurized hot water (1-20%, w/v) at 120-180°C in a 1 L Parr reactor for 10-60 min. The optimal hydrolysate for the fungal growth and endoxylanase production was obtained when 10% (w/v) of empty fruit bunch was treated at 120°C or 150°C for 10 min, giving an endoxylanase activity of 24.5 mU ml(-1) on RBB-Xylan and a saccharification activity of 5 U ml(-1) on xylan (DNS assay). When the hydrolysates were produced at higher temperatures, longer treatment times or higher biomass contents, only less than 20% of the above maximal endoxylanase activity was detected, possibly due to the higher carbohydrate concentrations in the medium. Transcriptome analysis showed that 3 endoxylanases (expression levels 59-100%, the highest level was set as 100%), 2 ?-xylosidases (4%), 4 side chain-cleaving arabinofuranosidases (1-95%), 1 acetyl xylan esterase (9%) and 2 ferulic acid esterases (0.3-9%) were produced together. PMID:24958131

Ottenheim, Christoph; Verdejo, Carl; Zimmermann, Wolfgang; Wu, Jin Chuan

2014-12-01

86

Efficient hydrogen production from the lignocellulosic energy crop Miscanthus by the extreme thermophilic bacteria Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana  

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Full Text Available Abstract Background The production of hydrogen from biomass by fermentation is one of the routes that can contribute to a future sustainable hydrogen economy. Lignocellulosic biomass is an attractive feedstock because of its abundance, low production costs and high polysaccharide content. Results Batch cultures of Caldicellulosiruptor saccharolyticus and Thermotoga neapolitana produced hydrogen, carbon dioxide and acetic acid as the main products from soluble saccharides in Miscanthus hydrolysate. The presence of fermentation inhibitors, such as furfural and 5-hydroxylmethyl furfural, in this lignocellulosic hydrolysate was avoided by the mild alkaline-pretreatment conditions at a low temperature of 75°C. Both microorganisms simultaneously and completely utilized all pentoses, hexoses and oligomeric saccharides up to a total concentration of 17 g l-1 in pH-controlled batch cultures. T. neapolitana showed a preference for glucose over xylose, which are the main sugars in the hydrolysate. Hydrogen yields of 2.9 to 3.4 mol H2 per mol of hexose, corresponding to 74 to 85% of the theoretical yield, were obtained in these batch fermentations. The yields were higher with cultures of C. saccharolyticus compared to T. neapolitana. In contrast, the rate of substrate consumption and hydrogen production was higher with T. neapolitana. At substrate concentrations exceeding 30 g l-1, sugar consumption was incomplete, and lower hydrogen yields of 2.0 to 2.4 mol per mol of consumed hexose were obtained. Conclusion Efficient hydrogen production in combination with simultaneous and complete utilization of all saccharides has been obtained during the growth of thermophilic bacteria on hydrolysate of the lignocellulosic feedstock Miscanthus. The use of thermophilic bacteria will therefore significantly contribute to the energy efficiency of a bioprocess for hydrogen production from biomass.

de Vrije Truus

2009-06-01

87

Sugars metabolism and ethanol production by different yeast strains from coffee industry wastes hydrolysates  

OpenAIRE

Significant amounts of wastes are generated by the coffee industry, among of which, coffee silverskin (CS) and spent coffee grounds (SCG) are the most abundantly generated during the beans roasting and instant coffee preparation, respectively. This study evaluated the sugars metabolism and production of ethanol by three different yeast strains (Saccharomyces cerevisiae, Pichia stipitis and Kluyveromyces fragilis) when cultivated in sugar rich hydrolysates produced by acid hydrolysis of CS and...

Mussatto, Solange I.; Machado, Erci?lia M. S.; Carneiro, Li?via M.; Teixeira, J. A.

2012-01-01

88

Sunflower protein hydrolysates reduce cholesterol micellar solubility.  

Science.gov (United States)

Plant protein hydrolysates are a source of bioactive peptides. There are peptides that decrease the micellar cholesterol solubility from bile acids and therefore may reduce in vivo cholesterol absorption. The presence of these peptides in sunflower protein hydrolysates has been studied. Sunflower protein hydrolysates produced with alcalase plus flavourzyme or with pepsin plus pancreatin inhibited in some degree the cholesterol incorporation to micelles. Protein hydrolysates generated after 30 min of hydrolysis with alcalase, and after 30 min of hydrolysis with pepsin, were the inhibitoriest of the cholesterol incorporation to micelles. The average amino acid hydrophobicity of inhibitory peptides in cholesterol micelles was higher than the observed in the corresponding protein hydrolysates. This high hydrophobicity probably favours their inclusion in the lipid micelles. In vivo, this inhibition may translate in a decrease of cholesterol absorption. Reported results show that a combination of different characteristics such as peptide size or hydrophobicity may be responsible of the inhibitory activity of generated peptides. PMID:19205886

Megías, Cristina; Pedroche, Justo; Del Mar Yust, María; Alaiz, Manuel; Girón-Calle, Julio; Millán, Francisco; Vioque, Javier

2009-06-01

89

Detoxification of acid pretreated spruce hydrolysates with ferrous sulfate and hydrogen peroxide improves enzymatic hydrolysis and fermentation.  

Science.gov (United States)

The aim of the present work was to investigate whether a detoxification method already in use during waste water treatment could be functional also for ethanol production based on lignocellulosic substrates. Chemical conditioning of spruce hydrolysate with hydrogen peroxide (H?O?) and ferrous sulfate (FeSO?) was shown to be an efficient strategy to remove significant amounts of inhibitory compounds and, simultaneously, to enhance the enzymatic hydrolysis and fermentability of the substrates. Without treatment, the hydrolysates were hardly fermentable with maximum ethanol concentration below 0.4 g/l. In contrast, treatment by 2.5 mM FeSO? and 150 mM H?O? yielded a maximum ethanol concentration of 8.3 g/l. PMID:24953967

Soudham, Venkata Prabhakar; Brandberg, Tomas; Mikkola, Jyri-Pekka; Larsson, Christer

2014-08-01

90

Saccharification of recalcitrant biomass and integration options for lignocellulosic sugars from Catchlight Energy’s sugar process (CLE Sugar  

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Full Text Available Abstract Background Woody biomass is one of the most abundant biomass feedstocks, besides agriculture residuals in the United States. The sustainable harvest residuals and thinnings alone are estimated at about 75 million tons/year. These forest residuals and thinnings could produce the equivalent of 5 billion gallons of lignocellulosic ethanol annually. Softwood biomass is the most recalcitrant biomass in pretreatment before an enzymatic hydrolysis. To utilize the most recalcitrant lignocellulosic materials, an efficient, industrially scalable and cost effective pretreatment method is needed. Results Obtaining a high yield of sugar from recalcitrant biomass generally requires a high severity of pretreatment with aggressive chemistry, followed by extensive conditioning, and large doses of enzymes. Catchlight Energy’s Sugar process, CLE Sugar, uses a low intensity, high throughput variation of bisulfite pulping to pretreat recalcitrant biomass, such as softwood forest residuals. By leveraging well-proven bisulfite technology and the rapid progress of enzyme suppliers, CLE Sugar can achieve a high yield of total biomass carbohydrate conversion to monomeric lignocellulosic sugars. For example, 85.8% of biomass carbohydrates are saccharified for un-debarked Loblolly pine chips (softwood, and 94.0% for debarked maple chips (hardwood. Furan compound formation was 1.29% of biomass feedstock for Loblolly pine and 1.10% for maple. At 17% solids hydrolysis of pretreated softwood, an enzyme dose of 0.075 g Sigma enzyme mixture/g dry pretreated (unwashed biomass was needed to achieve 8.1% total sugar titer in the hydrolysate and an overall prehydrolysate liquor plus enzymatic hydrolysis conversion yield of 76.6%. At a much lower enzyme dosage of 0.044 g CTec2 enzyme product/g dry (unwashed pretreated softwood, hydrolysis at 17% solids achieved 9.2% total sugar titer in the hydrolysate with an overall sugar yield of 85.0% in the combined prehydrolysate liquor and enzymatic hydrolysate. CLE Sugar has been demonstrated to be effective on hardwood and herbaceous biomass, making it truly feedstock flexible. Conclusions Different options exist for integrating lignocellulosic sugar into sugar-using operations. A sugar conversion plant may be adjacent to a CLE Sugar plant, and the CLE Sugar can be concentrated from the initial 10% sugar as needed. Concentrated sugars, however, can be shipped to remote sites such as ethanol plants or other sugar users. In such cases, options for shipping a dense form of sugars include (1 pretreated biomass with enzyme addition, (2 lignocellulosic sugar syrup, and (3 lignocellulosic sugar solid. These could provide the advantage of maximizing the use of existing assets.

Gao Johnway

2013-01-01

91

Semantic text mining support for lignocellulose research  

OpenAIRE

Abstract Background Biofuels produced from biomass are considered to be promising sustainable alternatives to fossil fuels. The conversion of lignocellulose into fermentable sugars for biofuels production requires the use of enzyme cocktails that can efficiently and economically hydrolyze lignocellulosic biomass. As many fungi naturally break down lignocellulose, the identification and characterization of the enzymes involved is a key challenge in the research and development of biomass-deriv...

Meurs Marie-Jean; Murphy Caitlin; Morgenstern Ingo; Butler Greg; Powlowski Justin; Tsang Adrian; Witte René

2012-01-01

92

Industrial scale chromatographic separation of valuable compounds from biomass hydrolysates and side streams  

Energy Technology Data Exchange (ETDEWEB)

Carbohydrates are composed of a number of various monosaccharides, glucose being the most abundant. Some of the monosaccharides are valuable compounds used in the food and pharmaceutical industries. They can be separated from biomass hydrolysates e.g. by chromatographic methods. In this thesis, chromatographic separation of valuable compounds using ion exchange resins was studied on an industrial scale. Of special interest were rare monosaccharides in biomass hydrolysates. A novel chromatographic separation process was developed for fucose, starting from pre-processed spent sulfite liquor. The core of the process consists of three chromatographic separations with different types of ion exchange resins. Chromatographic separation of galactose was tested with three biomass hydrolysates; lactose, gum arabic and hemicellulose hydrolysates. It was demonstrated that also galactose can be separated from complex carbohydrate mixtures. A recovery process for arabinose from citrus pectin liquid residual and for mannose from wood pulp hydrolysate were also developed and experimentally verified. In addition to monosaccharides, chromatographic separation of glycinebetaine from vinasse was examined with a hydrogen form weak acid cation exchange resin. The separation involves untypical peak formation depending, for example, on the pH and the cation composition. The retention mechanism was found to be hydrogen bonding between glycinebetaine and the resin. In the experimental part, all four resin types - strong acid cation, strong base anion, weak acid cation and weak base anion exchange resins - were used. In addition, adsorption equilibria data of seven monosaccharides and sucrose were measured with the resins in sodium and sulfate forms because such data have been lacking. It was found out that the isotherms of all sugars were linear under industrial conditions. A systematic method for conceptual process design and sequencing of chromatographic separation steps were developed. Heuristics were drawn from the current industrial practices also for the selection of a suitable ion exchange resin for the separation of a sugar from a biomass hydrolysate. (orig.)

Saari, P.

2011-06-15

93

LIGNOCELLULOSE NANOCOMPOSITE CONTAINING COPPER SULFIDE  

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Full Text Available Copper sulfide-containing lignocellulose nanocomposites with improved electroconductivity were obtained. Two methods for preparing the copper sulfide lignocellulose nanocomposites were developed. An optimization of the parameters for obtaining of the nanocomposites with respect to obtaining improved electroconductivity, economy, and lower quantities and concentration of copper and sulfur ions in waste waters was conducted. The mechanisms and schemes of delaying and subsequent connection of copper sulfides in the lignocellulosic matrix were investigated. The modification with a system of 2 components: cupric sulfate pentahydrate (CuSO4. 5H2O and sodium thiosulfate pentahydrate (Na2S2O3.5H2O for wood fibers is preferred. Optimal parameters were established for the process: 40 % of the reduction system; hydromodule M=1:6; and ratio of cupric sulfate pentahydrate:sodium thiosulfate pentahydrate = 1:2. The coordinative connection of copper ions with oxygen atoms of cellulose OH groups and aromatic nucleus in lignin macromolecule was observed.

Sanchi Nenkova

2011-04-01

94

Applications of Protein Hydrolysates in Biotechnology  

Science.gov (United States)

By definition, protein hydrolysates are the products that are obtained after the hydrolysis of proteins and this can be achieved by enzymes, acid or alkali. This broad definition encompasses all the products of protein hydrolysis - peptides, amino acids and minerals present in the protein and acid/alkali used to adjust pH (Pasupuleti 2006). Protein hydrolysates contain variable side chains depending on the enzymes used. These side chains could be carboxyl, amino, imidazole, sulfhydryl, etc. and they may exert specific physiological roles in animal, microbial, insect and plant cells. This introductory chapter reviews the applications of protein hydrolysates in biotechnology. The word biotechnology is so broad and for the purpose of this book, we define it as a set of technologies such as cell culture technology, bioprocessing technology that includes fermentations, genetic engineering technology, microbiology, and so on. This chapter provides introduction and leads to other chapters on manufacturing and applications of protein hydrolysates in biotechnology.

Pasupuleti, Vijai K.; Holmes, Chris; Demain, Arnold L.

95

Effect of ozonation on the reactivity of lignocellulose substrates in enzymatic hydrolyses to sugars  

Science.gov (United States)

The efficiency of pre-treatment of aspen wood with ozone for subsequent enzymatic hydrolysis into sugars is determined by the amount of absorbed ozone. The ozone absorption rate depended on the water content in the sample being ozonized and was maximum at a relative humidity of wood of ˜40%. As a result of ozone pre-treatment, the initial rate of the enzymatic hydrolysis of wood under the action of a cellulase complex increased eightfold, and the maximum yield of sugars increased tenfold depending on the ozone dose. The ozonation at ozone doses of more than 3 mol/PPU (phenylpropane structural unit of lignin) led to a decrease in the yield of sugars because of the oxidative destruction of cellulose and hemicellulose. The alkaline ozonation in 2 and 12% NaOH was inefficient because of the accompanying oxidation of carbohydrates and considerably decreased the yield of sugars.

Ben'ko, E. M.; Manisova, O. R.; Lunin, V. V.

2013-07-01

96

Modified organosolv as a fractionation process of lignocellulosic biomass for co-production of fuels and chemicals  

Energy Technology Data Exchange (ETDEWEB)

Modified organosolv is a process by which lignocellulosic biomass can be fractionated into its three main constituents, i.e. hemicellulose, cellulose and lignin. In the process, lignocellulosic biomass is brought into contact with an organic solvent-water mixture at elevated temperature and pressure. Thus, lignin is extracted from the biomass and hemicellulose is hydrolysed, while the solid residue (mainly cellulose) is made more accessible for enzymatic hydrolysis in the subsequent process step. The goal is to achieve full fractionation of all biomass fractions, including lignin, in a sufficient quality for production of (bio)chemicals. In this work, the effect of process conditions applied, type of organic solvent and the use of catalysts is explored.

Huijgen, W.J.J.; Van der Laan, R.R.; Reith, J.H. [ECN Solar Energy, Petten (Netherlands)

2008-05-15

97

Xylitol production from wheat straw hemicellulosic hydrolysate: hydrolysate detoxification and carbon source used for inoculum preparation  

OpenAIRE

Wheat straw hemicellulosic hydrolysate was used for xylitol bioproduction. The use of a xylose-containing medium to grow the inoculum did not favor the production of xylitol in the hydrolysate, which was submitted to a previous detoxification treatment with 2.5% activated charcoal for optimized removal of inhibitory compounds.

Canilha, Larissa; Carvalho, Walter; Felipe, Maria Das Grac?as Almeida; Almeida E Silva, Joa?o Batista

2008-01-01

98

Fractionating Recalcitrant Lignocellulose at Modest Reaction Conditions  

Energy Technology Data Exchange (ETDEWEB)

Effectively releasing the locked polysaccharides from recalcitrant lignocellulose to fermentable sugars is among the greatest technical and economic barriers to the realization of lignocellulose biorefineries because leading lignocellulose pre-treatment technologies suffer from low sugar yields, and/or severe reaction conditions, and/or high cellulase use, narrow substrate applicability, and high capital investment, etc. A new lignocellulose pre-treatment featuring modest reaction conditions (50 C and atmospheric pressure) was demonstrated to fractionate lignocellulose to amorphous cellulose, hemicellulose, lignin, and acetic acid by using a non-volatile cellulose solvent (concentrated phosphoric acid), a highly volatile organic solvent (acetone), and water. The highest sugar yields after enzymatic hydrolysis were attributed to no sugar degradation during the fractionation and the highest enzymatic cellulose digestibility ({approx}97% in 24 h) during the hydrolysis step at the enzyme loading of 15 filter paper units of cellulase and 60 IU of beta-glucosidase per gram of glucan. Isolation of high-value lignocellulose components (lignin, acetic acid, and hemicellulose) would greatly increase potential revenues of a lignocellulose biorefinery.

Zhang, Y.-H. Percival [Virginia Polytechnic Institute and State University (Virginia Tech); Ding, Shi-You [National Energy Renewable Laboratory; Mielenz, Jonathan R [ORNL; Cui, Jing-Biao [Dartmouth College; Elander, Richard T. [Dartmouth College; Laser, Mark [Dartmouth College; Himmel, Michael [ORNL; McMillan, James R. [National Energy Renewable Laboratory; Lynd, L. [Dartmouth College

2007-01-01

99

The NILE Project - Advances in the Conversion of Lignocellulosic Materials into Ethanol  

International Nuclear Information System (INIS)

NILE ('New Improvements for Lignocellulosic Ethanol') was an integrated European project (2005-2010) devoted to the conversion of lignocellulosic raw materials to ethanol. The main objectives were to design novel enzymes suitable for the hydrolysis of cellulose to glucose and new yeast strains able to efficiently converting all the sugars present in lignocellulose into ethanol. The project also included testing these new developments in an integrated pilot plant and evaluating the environmental and socio-economic impacts of implementing lignocellulosic ethanol on a large scale. Two model raw materials - spruce and wheat straw - both preconditioned with similar pretreatments, were used. Several approaches were explored to improve the saccharification of these pretreated raw materials such as searching for new efficient enzymes and enzyme engineering. Various genetic engineering methods were applied to obtain stable xylose- and arabinose-fermenting Saccharomyces cerevisiae strains that tolerate the toxic compounds present in lignocellulosic hydrolysates. The pilot plant was able to treat 2 tons of dry matter per day, and hydrolysis and fermentation could be run successively or simultaneously. A global model integrating the supply chain was used to assess the performance of lignocellulosic ethanol from an economical and environmental perspective. It was found that directed evolution of a specific enzyme of the cellulolytic cocktail produced by the industrial fungus, Trichoderma reesei, and modification of the composition of this cocktail led to improvements of the enzymatic hydrolysis of pretreated raw material. These results, however, were difficult to reproduce at a large scale. A substantial increase in the ethanol conversion yield and in specific ethanol productivity was obtained through a combination of metabolic engineering of yeast strains and fermentation process development. Pilot trials confirmed the good behaviour of the yeast strains in industrial conditions as well as the suitability of lignin residues as fuels. The ethanol cost and the greenhouse gas emissions were highly dependent on the supply chain but the best performing supply chains showed environmental and economic benefits. From a global standpoint, the results showed the necessity for an optimal integration of the process to co-develop all the steps of the process and to test the improvements in a flexible pilot plant, thus allowing the comparison of various configurations and their economic and environmental impacts to be determined. (authors)

100

Protein hydrolysate components attractive to tephritids  

International Nuclear Information System (INIS)

Volatiles from protein hydrolysates have for a long time been known to attract tephritids. Many volatiles from protein hydrolysates have previously been identified, but no highly attractive materials have been determined. There have been few studies on the very low boiling components, other than ammonia. Because protein hydrolysate is more attractive to tephritids at alkaline rather than at slightly acidic conditions, vapours from Nu-Lure insect bait (NLIB) at pH4.5 and pH8.5 were examined by gas chromatography/mass spectrometry (GC/MS). Compounds identified by GC/MS did not evoke very high responses, therefore attention was focused on ammonia. Because ammonia is a gas at ambient temperatures and at atmospheric pressure, a slow release system was devised. Ammonia was tested with walnut husk flies in California and was found to be primarily attractive to the female flies. (author). 10 refs, 4 figs

101

Biochemical and functional characterisation of casein and whey protein hydrolysates.  

OpenAIRE

Whey protein and sodium caseinate were hydrolysed with commercially available enzyme preparations. The resulting hydrolysates were characterised using several analytical characterisation methods and by determination of several functional properties. Subsequently, correlations between the biochemical characteristics themselves and between biochemical and functional properties were studied using multivariate regression analysis.Biochemical characteristics of hydrolysates were determined using u...

Ven, C.

2002-01-01

102

Physicochemical and bitterness properties of enzymatic pea protein hydrolysates.  

Science.gov (United States)

The effects of different proteolytic treatments on the physiochemical and bitterness properties of pea protein hydrolysates were investigated. A commercial pea protein isolate was digested using each of 5 different proteases to produce protein hydrolysates with varying properties. After 4 h of enzyme digestion, samples were clarified by centrifugation followed by desalting of the supernatant with a 1000 Da membrane; the retentates were then freeze-dried. Alcalase and Flavourzymetrade mark produced protein hydrolysates with significantly higher (P Flavourzyme, papain, and alcalase produced hydrolysates that contained the highest levels of aromatic amino acids, while trypsin hydrolysate had the highest levels of lysine and arginine. Papain hydrolysate contained high molecular weight peptides (10 to 178 kDa) while hydrolysates from the other 4 proteases contained predominantly low molecular weight peptides (Flavourzyme hydrolysate was significantly (P Flavourzyme hydrolysate had the least inhibitory activity. Sensory analysis showed that the alcalase hydrolysate was the most bitter while papain and alpha-chymotrypsin hydrolysates were the least. Among the 5 enzymes used in this study, papain and alpha-chymotrypsin appear to be the most desirable for producing high quality pea protein hydrolysates because of the low bitterness scores combined with a high level of angiotensin converting enzyme inhibition and moderate free radical scavenging activity. PMID:17995627

Humiski, L M; Aluko, R E

2007-10-01

103

Lignocellulosic Biomass Conversion: Status and Prospects  

Science.gov (United States)

The Advanced Technology Environmental and Energy Center (ATEEC) provides this presentation on lignocellulosic biomass conversion from Christopher Scarlata and Amie Sluiter. U.S. energy consumption and supply are covered as well as an overview of lignocellulosic biomass and the outlook for biomass technology in the United States. Users must download this resource for viewing, which requires a free log-in. There is no cost to download the item.

Scarlata, C. (Christopher)

104

Developing symbiotic consortia for lignocellulosic biofuel production  

Energy Technology Data Exchange (ETDEWEB)

The search for petroleum alternatives has motivated intense research into biological breakdown of lignocellulose to produce liquid fuels such as ethanol. Degradation of lignocellulose for biofuel production is a difficult process which is limited by, among other factors, the recalcitrance of lignocellulose and biological toxicity of the products. Consolidated bioprocessing has been suggested as an efficient and economical method of producing low value products from lignocellulose; however, it is not clear whether this would be accomplished more efficiently with a single organism or community of organisms. This review highlights examples of mixtures of microbes in the context of conceptual models for developing symbiotic consortia for biofuel production from lignocellulose. Engineering a symbiosis within consortia is a putative means of improving both process efficiency and stability relative to monoculture. Because microbes often interact and exist attached to surfaces, quorum sensing and biofilm formation are also discussed in terms of consortia development and stability. An engineered, symbiotic culture of multiple organisms may be a means of assembling a novel combination of metabolic capabilities that can efficiently produce biofuel from lignocellulose. (orig.)

Zuroff, Trevor R.; Curtis, Wayne R. [Pennsylvania State Univ., University Park, PA (United States). Dept. of Chemical Engineering

2012-02-15

105

Development of a phenotypic assay for characterisation of ethanologenic yeast strain sensitivity to inhibitors released from lignocellulosic feedstocks.  

Science.gov (United States)

Inhibitors released by the breakdown of plant cell walls prevent efficient conversion of sugar into ethanol. The aim of this study was to develop a fast and reliable inhibitor sensitivity assay for ethanologenic yeast strains. The assay comprised bespoke 96-well plates containing inhibitors in isolation or combination in a format that was compatible with the Phenotypic Microarray Omnilog reader (Biolog, hayward, CA, USA). A redox reporter within the assay permits analysis of inhibitor sensitivity in aerobic and/or anaerobic conditions. Results from the assay were verified using growth on spot plates and tolerance assays in which maintenance of viability was assessed. The assay allows for individual and synergistic effects of inhibitors to be determined. It was observed that the presence of both acetic and formic acid significantly inhibited the yeast strains assessed, although this impact could be partially mitigated by buffering to neutral pH. Scheffersomyces stipitis, Candida spp., and Pichia guilliermondii demonstrated increased sensitivity to short chain weak acids at concentrations typically present in lignocellulosic hydrolysates. S. cerevisiae exhibited robustness to short chain weak acids at these concentrations. However, S. stipitis, Candida spp., and P. guilliermondii displayed increased tolerance to HMF when compared to that observed for S. cerevisiae. The results demonstrate that the phenotypic microarray assay developed in the current study is a valuable tool that can be used to identify yeast strains with desirable resistance to inhibitory compounds found in lignocellulosic hydrolysates. PMID:24664516

Greetham, D; Wimalasena, T; Kerruish, D W M; Brindley, S; Ibbett, R N; Linforth, R L; Tucker, G; Phister, T G; Smart, K A

2014-06-01

106

Homogen und heterogen katalysierte Hydrolyse von Lignin  

OpenAIRE

Lignin ist aufgrund seiner Zusammensetzung aus Phenylpropan-Untereinheiten eine potentielle Ausgangsverbindung für die Herstellung phenolischer Produkte. Lignin Modellverbindungen zeigen, dass bei der Lignin-Hydrolyse mit basischen Katalysatoren vorwiegend die ß-O-4 Etherbindung gespalten werden. Phenolische Monomere sind die Primärprodukte dieser Reaktionsroute, deren Ausbeute jedoch durch Folgereaktionen zu Oligomeren limitiert ist. Durch Reaktion mit Borsäure können diese Oligomerisie...

Roberts, Virginia

2008-01-01

107

Enhancing the anaerobic digestion of lignocellulose of municipal solid waste using a microbial pretreatment method.  

Science.gov (United States)

The use of biological pretreatment in anaerobic digestion systems has some potential; however, to date, these methods have not been able to effectively increase methane production of lignocellulose of municipal solid waste (LMSW). In this study a thermophilic microbial consortium (MC1) was used as a pretreatment method in order to enhance biogas and methane production yields. The results indicated that sCOD concentration increased significantly in the early stages of pretreatment. Ethanol, acetic acid, propionic acid, and butyric acid were the predominant volatile organic products in the MC1 hydrolysate. Biogas and methane production yields of LMSW significantly increased following MC1 pretreatment. In addition, the methane production rate of the treated LMSW was greater than that observed from the untreated sample. PMID:24365784

Yuan, Xufeng; Wen, Boting; Ma, Xuguang; Zhu, Wanbin; Wang, Xiaofen; Chen, Shaojiang; Cui, Zongjun

2014-02-01

108

Ectoine production from lignocellulosic biomass-derived sugars by engineered Halomonas elongata.  

Science.gov (United States)

In this study, the water-retaining cyclic amino acid ectoine was produced from a variety of sugars, including glucose, xylose, cellobiose, and glucose/xylose mixture using engineered Halomonas elongata. When grown on xylose as the sole carbon source, H. elongata produced 333 mmol/kg fresh cell weight (FW) of ectoine, which was 1.4-fold higher than that produced from glucose. To improve ectoine production, an ectD deficient H. elongata mutant was constructed. The engineered H. elongata produced 377 mmol/kg FW of ectoine from a glucose/xylose mixture. Ectoine was also produced from rice straw hydrolysate. These results show that H. elongata can produce ectoine from a variety of sugars derived from lignocellulosic biomass and thus has tremendous potential as a host for producing useful compounds from biomass resources. PMID:23765002

Tanimura, Kosuke; Nakayama, Hideki; Tanaka, Tsutomu; Kondo, Akihiko

2013-08-01

109

Ethanol production from wet-exploded wheat straw hydrolysate by thermophilic anaerobic bacterium Thermoanaerobacter BG1L1 in a continuous immobilized reactor  

DEFF Research Database (Denmark)

Thermophilic ethanol fermentation of wet-exploded wheat straw hydrolysate was investigated in a continuous immobilized reactor system. The experiments were carried out in a lab-scale fluidized bed reactor (FBR) at 70C. Undetoxified wheat straw hydrolysate was used (3-12% dry matter), corresponding to sugar mixtures of glucose and xylose ranging from 12 to 41 g/l. The organism, thermophilic anaerobic bacterium Thermoanaerobacter BG1L1, exhibited significant resistance to high levels of acetic acid (up to 10 g/l) and other metabolic inhibitors present in the hydrolysate. Although the hydrolysate was not detoxified, ethanol yield in a range of 0.39-0.42 g/g was obtained. Overall, sugar efficiency to ethanol was 68-76%. The reactor was operated continuously for approximately 143 days, and no contamination was seen without the use of any agent for preventing bacterial infections. The tested microorganism has considerable potential to be a novel candidate for lignocellulose bioconversion into ethanol. The work reported here also demonstrates that the use of FBR configuration might be a viable approach for thermophilic anaerobic ethanol fermentation.

Georgieva, Tania I.; Mikkelsen, Marie Just

2008-01-01

110

Lignocellulosic biomass pretreatment using AFEX.  

Science.gov (United States)

Although cellulose is the most abundant organic molecule, its susceptibility to hydrolysis is restricted due to the rigid lignin and hemicellulose protection surrounding the cellulose micro fibrils. Therefore, an effective pretreatment is necessary to liberate the cellulose from the lignin-hemicellulose seal and also reduce cellulosic crystallinity. Some of the available pretreatment techniques include acid hydrolysis, steam explosion, ammonia fiber expansion (AFEX), alkaline wet oxidation, and hot water pretreatment. Besides reducing lignocellulosic recalcitrance, an ideal pretreatment must also minimize formation of degradation products that inhibit subsequent hydrolysis and fermentation. AFEX is an important pretreatment technology that utilizes both physical (high temperature and pressure) and chemical (ammonia) processes to achieve effective pretreatment. Besides increasing the surface accessibility for hydrolysis, AFEX promotes cellulose decrystallization and partial hemicellulose depolymerization and reduces the lignin recalcitrance in the treated biomass. Theoretical glucose yield upon optimal enzymatic hydrolysis on AFEX-treated corn stover is approximately 98%. Furthermore, AFEX offers several unique advantages over other pretreatments, which include near complete recovery of the pretreatment chemical (ammonia), nutrient addition for microbial growth through the remaining ammonia on pretreated biomass, and not requiring a washing step during the process which facilitates high solid loading hydrolysis. This chapter provides a detailed practical procedure to perform AFEX, design the reactor, determine the mass balances, and conduct the process safely. PMID:19768616

Balan, Venkatesh; Bals, Bryan; Chundawat, Shishir P S; Marshall, Derek; Dale, Bruce E

2009-01-01

111

Pretreatments to enhance the digestibility of lignocellulosic biomass  

OpenAIRE

Lignocellulosic biomass represents a rather unused source for biogas and ethanol production. Many factors, like lignin content, crystallinity of cellulose, and particle size, limit the digestibility of the hemicellulose and cellulose present in the lignocellulosic biomass. Pretreatments have as a goal to improve the digestibility of the lignocellulosic biomass. Each pretreatment has its own effect(s) on the cellulose, hemicellulose and lignin; the three main components of lignocellulosic biom...

Hendriks, A. T. W. M.; Zeeman, G.

2009-01-01

112

Evaluation of the activated charcoals and adsorption conditions used in the treatment of sugarcane bagasse hydrolysate for xylitol production  

Directory of Open Access Journals (Sweden)

Full Text Available Xylitol has sweetening, anticariogenic and clinical properties that have attracted the attention of the food and pharmaceutical industries. The conversion of sugars from lignocellulosic biomass into xylitol by D-xylose-fermenting yeast represents an alternative to the chemical process for producing this polyol. A good source of D-xylose is sugarcane bagasse, which can be hydrolyzed with dilute acid. However, acetic acid, which is toxic to the yeast, also appears in the hydrolysate, inhibiting microbe metabolism. Xylitol production depends on the initial D-xylose concentration, which can be increased by concentrating the hydrolysate by vacuum evaporation. However, with this procedure the amount of acetic acid is also increased, aggravating the problem of cell inhibition. Hydrolysate treatment with powdered activated charcoal is used to remove or decrease the concentration of this inhibitor, improving xylitol productivity as a consequence. Our work was an attempt to improve the fermentation of Candida guilliermondii yeast in sugarcane bagasse hydrolysate by treating the medium with seven types of commercial powdered activated charcoals (Synth, Carbon Delta A, Carbon Delta G, Carbon 117, Carbon 118L, Carbon 147 and Carvorite, each with its own unique physicochemical properties. Various adsorption conditions were established for the variables temperature, contact time, shaking, pH and charcoal concentration. The experiments were based on multivariate statistical concepts, with the application of fractional factorial design techniques to identify the variables that are important in the process. Subsequently, the levels of these variables were quantified by overlaying the level curves, which permitted the establishment of the best adsorption conditions for attaining high levels of xylitol volumetric productivity and D-xylose-to-xylitol conversion. This procedure consisted in increasing the original pH of the hydrolysate to 7.0 with CaO and reducing it to 5.5 with H3PO4. Next, the hydrolysate was treated under adsorption conditions employing CDA powdered activated charcoal (1% for 30 min at 60ºC, 100 rpm and pH 2.5. The optimized xylitol volumetric productivity (0.50 g/L h corresponded to a D-xylose-to-xylitol conversion of 0.66 g/g.

J. M. Marton

2006-03-01

113

Bioconversion of lignocellulose-derived sugars to ethanol by engineered Saccharomyces cerevisiae.  

Science.gov (United States)

Lignocellulosic biomass from agricultural and agro-industrial residues represents one of the most important renewable resources that can be utilized for the biological production of ethanol. The yeast Saccharomyces cerevisiae is widely used for the commercial production of bioethanol from sucrose or starch-derived glucose. While glucose and other hexose sugars like galactose and mannose can be fermented to ethanol by S. cerevisiae, the major pentose sugars D-xylose and L-arabinose remain unutilized. Nevertheless, D-xylulose, the keto isomer of xylose, can be fermented slowly by the yeast and thus, the incorporation of functional routes for the conversion of xylose and arabinose to xylulose or xylulose-5-phosphate in Saccharomyces cerevisiae can help to improve the ethanol productivity and make the fermentation process more cost-effective. Other crucial bottlenecks in pentose fermentation include low activity of the pentose phosphate pathway enzymes and competitive inhibition of xylose and arabinose transport into the cell cytoplasm by glucose and other hexose sugars. Along with a brief introduction of the pretreatment of lignocellulose and detoxification of the hydrolysate, this review provides an updated overview of (a) the key steps involved in the uptake and metabolism of the hexose sugars: glucose, galactose, and mannose, together with the pentose sugars: xylose and arabinose, (b) various factors that play a major role in the efficient fermentation of pentose sugars along with hexose sugars, and (c) the approaches used to overcome the metabolic constraints in the production of bioethanol from lignocellulose-derived sugars by developing recombinant S. cerevisiae strains. PMID:21204601

Madhavan, Anjali; Srivastava, Aradhana; Kondo, Akihiko; Bisaria, Virendra S

2012-03-01

114

Ethanol production with dilute acid hydrolysis using partially dried lignocellulosics  

Science.gov (United States)

A process of converting lignocellulosic biomass to ethanol, comprising hydrolyzing lignocellulosic materials by subjecting dried lignocellulosic material in a reactor to a catalyst comprised of a dilute solution of a strong acid and a metal salt to lower the activation energy (i.e., the temperature) of cellulose hydrolysis and ultimately obtain higher sugar yields.

Nguyen, Quang A. (Chesterfield, MO); Keller, Fred A. (Lakewood, CO); Tucker, Melvin P. (Lakewood, CO)

2003-12-09

115

Biofilm production by Zymomonas mobilis enhances ethanol production and tolerance to toxic inhibitors from rice bran hydrolysate.  

Science.gov (United States)

Microorganisms play a significant role in bioethanol production from lignocellulosic material. A challenging problem in bioconversion of rice bran is the presence of toxic inhibitors in lignocellulosic acid hydrolysate. Various strains of Zymomonas mobilis (ZM4, TISTR 405, 548, 550 and 551) grown under biofilm or planktonic modes were used in this study to examine their potential for bioconversion of rice bran hydrolysate and ethanol production efficiencies. Z. mobilis readily formed bacterial attachment on plastic surfaces, but not on glass surfaces. Additionally, the biofilms formed on plastic surfaces steadily increased over time, while those formed on glass were speculated to cycle through accumulation and detachment phases. Microscopic analysis revealed that Z. mobilis ZM4 rapidly developed homogeneous biofilm structures within 24 hours, while other Z. mobilis strains developed heterogeneous biofilm structures. ZM4 biofilms were thicker and seemed to be more stable than other Z. mobilis strains. The percentage of live cells in biofilms was greater than that for planktonic cells (54.32 ± 7.10% vs. 28.69 ± 3.03%), suggesting that biofilms serve as a protective niche for growth of bacteria in the presence of toxic inhibitors in the rice bran hydrolysate. The metabolic activity of ZM4 grown as a biofilm was also higher than the same strain grown planktonically, as measured by ethanol production from rice bran hydrolysate (13.40 ± 2.43 g/L vs. 0.432 ± 0.29 g/L, with percent theoretical ethanol yields of 72.47 ± 6.13% and 3.71 ± 5.24% respectively). Strain TISTR 551 was also quite metabolically active, with ethanol production by biofilm and planktonically grown cells of 8.956 ± 4.06 g/L and 0.0846 ± 0.064 g/L (percent theoretical yields were 48.37 ± 16.64% and 2.046 ± 1.58%, respectively). This study illustrates the potential for enhancing ethanol production by utilizing bacterial biofilms in the bioconversion of a readily available and normally unusable low value by-product of rice farming. PMID:24930397

Todhanakasem, Tatsaporn; Sangsutthiseree, Atit; Areerat, Kamonchanok; Young, Glenn M; Thanonkeo, Pornthap

2014-09-25

116

Laccase Application for Upgrading of Lignocellulose Fibers  

Directory of Open Access Journals (Sweden)

Full Text Available Laccases have the ability to oxidize both phenolic and trough mediators non-phenolic lignin related compounds. When reacting on lignin, they can display both ligninolytic and polymerizing (cross-inking abilities, which makes them very useful for their application in industries based on lignocellulose material. Most of the published papers and applications of laccase and laccase-mediator systems on lignocellulose material relate to the pulp, paper and textile industry. Recent research has been done in terms of laccase assisted biografting of phenols and other compounds on wood surface and use of laccase for adhesion enhancement in fiberboard production. They can be introduced to wood technology as environmentally friendly enzymes. The paper reviews the application of laccases in industries based on lignocellulose material and discusses the future outlook and development in the above mentioned fields.

Maja Vaukner Gabri?

2015-04-01

117

Evaluation of oat hull hemicellulosic hydrolysate fermentability employing Pichia stipitis  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Oat hull hemicellulosic hydrolysate obtained by diluted acid hydrolysis was employed as fermentation medium for Pichia stipitis cultivation. A comparison between the use of treated hydrolysate with 1% activated charcoal to reduce the toxic compounds generated during the hydrolysis process and untrea [...] ted hydrolysate as a control was conducted. In the cultures using treated hydrolysate the total consumption of glucose, low xylose consumption and ethanol and glycerol formation were observed. The medium formulated with untreated hydrolysate showed morphological cell modifications with consequently cell death, no ethanol formation and formation of glycerol as byproduct of fermentative process, probably as a response to stressful conditions to yeast due to presence of high concentration of toxic compounds. Thus, further studies are suggested in order to determine the best conditions for hydrolysis and detoxification of the hydrolysate to improve the fermentative performance of P. stipitis.

Luciana Cristina Silveira, Chaud; Débora Danielle Virgínio da, Silva; Rafael Taino de, Mattos; Maria das Graças de Almeida, Felipe.

2012-10-01

118

Dissecting a complex chemical stress: chemogenomic profiling of plant hydrolysates.  

Science.gov (United States)

The efficient production of biofuels from cellulosic feedstocks will require the efficient fermentation of the sugars in hydrolyzed plant material. Unfortunately, plant hydrolysates also contain many compounds that inhibit microbial growth and fermentation. We used DNA-barcoded mutant libraries to identify genes that are important for hydrolysate tolerance in both Zymomonas mobilis (44 genes) and Saccharomyces cerevisiae (99 genes). Overexpression of a Z. mobilis tolerance gene of unknown function (ZMO1875) improved its specific ethanol productivity 2.4-fold in the presence of miscanthus hydrolysate. However, a mixture of 37 hydrolysate-derived inhibitors was not sufficient to explain the fitness profile of plant hydrolysate. To deconstruct the fitness profile of hydrolysate, we profiled the 37 inhibitors against a library of Z. mobilis mutants and we modeled fitness in hydrolysate as a mixture of fitness in its components. By examining outliers in this model, we identified methylglyoxal as a previously unknown component of hydrolysate. Our work provides a general strategy to dissect how microbes respond to a complex chemical stress and should enable further engineering of hydrolysate tolerance. PMID:23774757

Skerker, Jeffrey M; Leon, Dacia; Price, Morgan N; Mar, Jordan S; Tarjan, Daniel R; Wetmore, Kelly M; Deutschbauer, Adam M; Baumohl, Jason K; Bauer, Stefan; Ibáñez, Ana B; Mitchell, Valerie D; Wu, Cindy H; Hu, Ping; Hazen, Terry; Arkin, Adam P

2013-01-01

119

Engineering Sugar Utilization and Microbial Tolerance toward Lignocellulose Conversion.  

Science.gov (United States)

Production of fuels and chemicals through a fermentation-based manufacturing process that uses renewable feedstock such as lignocellulosic biomass is a desirable alternative to petrochemicals. Although it is still in its infancy, synthetic biology offers great potential to overcome the challenges associated with lignocellulose conversion. In this review, we will summarize the identification and optimization of synthetic biological parts used to enhance the utilization of lignocellulose-derived sugars and to increase the biocatalyst tolerance for lignocellulose-derived fermentation inhibitors. We will also discuss the ongoing efforts and future applications of synthetic integrated biological systems used to improve lignocellulose conversion. PMID:25741507

Nieves, Lizbeth M; Panyon, Larry A; Wang, Xuan

2015-01-01

120

Engineering Sugar Utilization and Microbial Tolerance toward Lignocellulose Conversion  

Science.gov (United States)

Production of fuels and chemicals through a fermentation-based manufacturing process that uses renewable feedstock such as lignocellulosic biomass is a desirable alternative to petrochemicals. Although it is still in its infancy, synthetic biology offers great potential to overcome the challenges associated with lignocellulose conversion. In this review, we will summarize the identification and optimization of synthetic biological parts used to enhance the utilization of lignocellulose-derived sugars and to increase the biocatalyst tolerance for lignocellulose-derived fermentation inhibitors. We will also discuss the ongoing efforts and future applications of synthetic integrated biological systems used to improve lignocellulose conversion. PMID:25741507

Nieves, Lizbeth M.; Panyon, Larry A.; Wang, Xuan

2015-01-01

121

GENETICALLY MODIFIED LIGNOCELLULOSIC BIOMASS FOR IMPROVEMENT OF ETHANOL PRODUCTION  

Directory of Open Access Journals (Sweden)

Full Text Available Production of ethanol from lignocellulosic feed-stocks is of growing interest worldwide in recent years. However, we are currently still facing significant technical challenges to make it economically feasible on an industrial scale. Genetically modified lignocellulosic biomass has provided a potential alternative to address such challenges. Some studies have shown that genetically modified lignocellulosic biomass can increase its yield, decreasing its enzymatic hydrolysis cost and altering its composition and structure for ethanol production. Moreover, the modified lignocellulosic biomass also makes it possible to simplify the ethanol production procedures from lignocellulosic feed-stocks.

Qijun Wang

2010-02-01

122

Production of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) by Burkholderia sacchari using wheat straw hydrolysates and gamma-butyrolactone.  

Science.gov (United States)

Burkholderia sacchari DSM 17165 is able to grow and produce poly(3-hydroxybutyrate) both on hexoses and pentoses. In a previous study, wheat straw lignocellulosic hydrolysates (WSH) containing high C6 and C5 sugar concentrations were shown to be excellent carbon sources for P(3HB) production. Using a similar feeding strategy developed for P(3HB) production based on WSH, fed-batch cultures were developed aiming at the production of the copolymer P(3HB-co-4HB) (poly(3-hydroxybutyrate-co-4-hydroxybutyrate)) by B. sacchari. The ability of this strain to synthesize P(3HB-co-4HB) was first shown in shake flasks using gamma-butyrolactone (GBL) as precursor of the 4HB units. Fed-batch cultures using glucose as carbon source (control) and GBL were developed to achieve high copolymer productivities and 4HB incorporations. The attained P(3HB-co-4HB) productivity and 4HB molar% were 0.7g/(Lh) and 4.7molar%, respectively. The 4HB incorporation was improved to 6.3 and 11.8molar% by addition of 2g/L propionic and acetic acid, respectively. When WSH were used as carbon source under the same feeding conditions, the values achieved were 0.5g/(Lh) and 5.0molar%, respectively. Burkholderia sacchari, a strain able to produce biopolymers based on xylose-rich lignocellulosic hydrolysates, is for the first time reported to produce P(3HB-co-4HB) using gamma butyrolactone as precursor. PMID:24811901

Cesário, M Teresa; Raposo, Rodrigo S; M D de Almeida, M Catarina; van Keulen, Frederik; Ferreira, Bruno S; Telo, João P; R da Fonseca, M Manuela

2014-11-01

123

[Protein hydrolysate as a dietetic resource  

Science.gov (United States)

OBJECTIVE: The central goal of this paper was to study the application of beef meat and poultry (turkey and chicken) hydrolysates to the preparations used in our Brazilian current feeding practices. METHODS: The various kinds of meat were hydrolyzed with fresh pineapple under similar conditions to those daily used at home. The selection of three types of preparation was dependent on whether their contents included starch or gelatin and liquid, like soup, mousse and fruit-shake. Hydrolysate were added to the preparations as part of the liquid content of their recipes. The acceptability of the preparations was checked out by employing the hedonic-scale affective test with untrained tasters. Variance analysis and the Tukeýs test were performed with a 5% level of significance for the results.RESULTS: The selected recipes were the following: bitterroot soup, fruit and vegetable-shakes and grape mousse, all of them containing starch or gelatin as an element to camouflage the bitter taste of the aminoacids. The preparations were well accepted: approximately 76% of the tasters reported having liked the soup at least somewhat; as to the shakes, more than 50% gave positive answers, and as to the mousse, approximately 88% reported having liked it. There were no statistically significant differences (phydrolysates in all the preparations tested. CONCLUSIONS: The use of hydrolysed meat to replace liquid content of recipes is highly practicable, requiring only an adequate selection of recipes and their ingredients, that should include starch and gelatin in order to get fully satisfactory products. These preparations might serve as a basis for other ones, adapted to each diet. PMID:14685623

Silva, M E; Mazzilli, R N; Barbieri, D

1998-01-01

124

Catalytic fast pyrolysis of lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

Increasing energy demand, especially in the transportation sector, and soaring CO2 emissions necessitate the exploitation of renewable sources of energy. Despite the large variety of new energy Q3 carriers, liquid hydrocarbon still appears to be the most attractive and feasible form of transportation fuel taking into account the energy density, stability and existing infrastructure. Biomass is an abundant, renewable source of energy; however, utilizing it in a cost-effective way is still a substantial challenge. Lignocellulose is composed of three major biopolymers, namely cellulose, hemicellulose and lignin. Fast pyrolysis of biomass is recognized as an efficient and feasible process to selectively convert lignocellulose into a liquid fuel—bio-oil. However bio-oil from fast pyrolysis contains a large amount of oxygen, distributed in hundreds of oxygenates. These oxygenates are the cause of many negative properties, such as low heating values, high corrosiveness, high viscosity, and instability; they also greatly Q4 limit the application of bio-oil particularly as transportation fuel. Hydrocarbons derived from biomass are most attractive because of their high energy density and compatibility with the existing infrastructure. Thus, converting lignocellulose into transportation fuels via catalytic fast pyrolysis has attracted much attention. Many studies related to catalytic fast pyrolysis of biomass have been published. The main challenge of this process is the development of active and stable catalysts that can deal with a large variety of decomposition intermediates from lignocellulose. This review starts with the current understanding of the chemistry in fast pyrolysis of lignocellulose and focuses on the development of catalysts in catalytic fast pyrolysis. Recent progress in the experimental studies on catalytic fast pyrolysis of biomass is also summarized with the emphasis on bio-oil yields and quality.

Liu, Changjun; Wang, Huamin; Karim, Ayman M.; Sun, Junming; Wang, Yong

2014-11-21

125

Catalytic fast pyrolysis of lignocellulosic biomass.  

Science.gov (United States)

Increasing energy demand, especially in the transportation sector, and soaring CO2 emissions necessitate the exploitation of renewable sources of energy. Despite the large variety of new energy carriers, liquid hydrocarbon still appears to be the most attractive and feasible form of transportation fuel taking into account the energy density, stability and existing infrastructure. Biomass is an abundant, renewable source of energy; however, utilizing it in a cost-effective way is still a substantial challenge. Lignocellulose is composed of three major biopolymers, namely cellulose, hemicellulose and lignin. Fast pyrolysis of biomass is recognized as an efficient and feasible process to selectively convert lignocellulose into a liquid fuel-bio-oil. However bio-oil from fast pyrolysis contains a large amount of oxygen, distributed in hundreds of oxygenates. These oxygenates are the cause of many negative properties, such as low heating value, high corrosiveness, high viscosity, and instability; they also greatly limit the application of bio-oil particularly as transportation fuel. Hydrocarbons derived from biomass are most attractive because of their high energy density and compatibility with the existing infrastructure. Thus, converting lignocellulose into transportation fuels via catalytic fast pyrolysis has attracted much attention. Many studies related to catalytic fast pyrolysis of biomass have been published. The main challenge of this process is the development of active and stable catalysts that can deal with a large variety of decomposition intermediates from lignocellulose. This review starts with the current understanding of the chemistry in fast pyrolysis of lignocellulose and focuses on the development of catalysts in catalytic fast pyrolysis. Recent progress in the experimental studies on catalytic fast pyrolysis of biomass is also summarized with the emphasis on bio-oil yields and quality. PMID:24801125

Liu, Changjun; Wang, Huamin; Karim, Ayman M; Sun, Junming; Wang, Yong

2014-11-21

126

Production of Ethanol from Cocoa Pod Hydrolysate  

OpenAIRE

Cocoa pod (Theobroma cacao L.) hydrolysate was hydrolyzed into glucose using hydrochloric, sulphuric and nitric acids, respectively. The concentration of each acid was set at 0.25 M, 0.50 M, 0.75 M, 1.00 M and 1.25 M. They were treated under two different temperatures and time at 75?C and 90?C for 2 h and 4 h, respectively. The results showed that hydrolysis in 1.00 M of hydrochloric acid at 75?C for 4 h had produced the highest glucose content of 30.7% w/v compared to all others acids tre...

Othman Abd Samah; Salihan Sias

2011-01-01

127

Antioxidant Activity of Protein Hydrolysates of Fish and Chicken Bones  

OpenAIRE

Argentine croaker (Umbrina canosai) and chicken (Gallus domesticus) bones were hydrolyzed with different proteases (Flavourzyme, ?-Chymotrypsin and Trypsin) in order to obtain peptides whit antioxidant activity. The hydrolysates showed different degrees of hydrolysis and antioxidant activity. The antioxidant power of the hydrolysates was evaluated through inhibition of the peroxidation of linoleic acid, hydroxyl radical scavenging, DPPH free radical scavenging, ABTS free radical scavenging a...

Centenaro, G. S.; Mellado, M. S.; Prentice-herna?ndez, C.

2011-01-01

128

Antioxidant Activity of Protein Hydrolysates of Fish and Chicken Bones  

Directory of Open Access Journals (Sweden)

Full Text Available Argentine croaker (Umbrina canosai and chicken (Gallus domesticus bones were hydrolyzed with different proteases (Flavourzyme, ?-Chymotrypsin and Trypsin in order to obtain peptides whit antioxidant activity. The hydrolysates showed different degrees of hydrolysis and antioxidant activity. The antioxidant power of the hydrolysates was evaluated through inhibition of the peroxidation of linoleic acid, hydroxyl radical scavenging, DPPH free radical scavenging, ABTS free radical scavenging and reducing power. The hydrolysates of the fish (FF and chicken (CF bones produced with Flavourzyme had high activity of lipid peroxidation inhibition (77.3 and 61.6%, respectively and moderate DPPH free radical scavenging, ABTS scavenging and hydroxyl radical scavenging activity. The fraction <3000 Da was the main constituent of the six hydrolysates followed by the fraction <1000 Da. The results of this study suggest that protein hydrolysates of fish and chicken bones are good sources of natural antioxidants. FF showed better performance e can be used as antioxidant substance.

G.S. Centenaro

2011-08-01

129

The NILE Project — Advances in the Conversion of Lignocellulosic Materials into Ethanol Le projet NILE et la conversion des matériaux lignocellulosiques en éthanol  

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Full Text Available NILE ("New Improvements for Lignocellulosic Ethanol" was an integrated European project (2005-2010 devoted to the conversion of lignocellulosic raw materials to ethanol. The main objectives were to design novel enzymes suitable for the hydrolysis of cellulose to glucose and new yeast strains able to efficiently converting all the sugars present in lignocellulose into ethanol. The project also included testing these new developments in an integrated pilot plant and evaluating the environmental and socio-economic impacts of implementing lignocellulosic ethanol on a large scale. Two model raw materials – spruce and wheat straw – both preconditioned with similar pretreatments, were used. Several approaches were explored to improve the saccharification of these pretreated raw materials such as searching for new efficient enzymes and enzyme engineering. Various genetic engineering methods were applied to obtain stable xylose- and arabinose-fermenting Saccharomyces cerevisiae strains that tolerate the toxic compounds present in lignocellulosic hydrolysates. The pilot plant was able to treat 2 tons of dry matter per day, and hydrolysis and fermentation could be run successively or simultaneously. A global model integrating the supply chain was used to assess the performance of lignocellulosic ethanol from an economical and environmental perspective. It was found that directed evolution of a specific enzyme of the cellulolytic cocktail produced by the industrial fungus, Trichoderma reesei, and modification of the composition of this cocktail led to improvements of the enzymatic hydrolysis of pretreated raw material. These results, however, were difficult to reproduce at a large scale. A substantial increase in the ethanol conversion yield and in specific ethanol productivity was obtained through a combination of metabolic engineering of yeast strains and fermentation process development. Pilot trials confirmed the good behaviour of the yeast strains in industrial conditions as well as the suitability of lignin residues as fuels. The ethanol cost and the greenhouse gas emissions were highly dependent on the supply chain but the best performing supply chains showed environmental and economic benefits. From a global standpoint, the results showed the necessity for an optimal integration of the process to co-develop all the steps of the process and to test the improvements in a flexible pilot plant, thus allowing the comparison of various configurations and their economic and environmental impacts to be determined. Le projet NILE, acronyme de "New Improvements for Lignocellulosic Ethanol", était un projet européen (2005-2010 consacré à la conversion des matières premières lignocellulosiques en éthanol. Ses principaux objectifs étaient de concevoir de nouvelles enzymes adaptées à l’hydrolyse de la cellulose en glucose et de nouvelles souches de levure capables de convertir efficacement tous les sucres présents dans la lignocellulose en éthanol. Une autre partie du projet consistait à tester ces nouveaux systèmes dans une installation pilote et à évaluer les impacts environnementaux et socio-économiques de la production et utilisation à grande échelle d’éthanol lignocellulosique. Deux matières premières modèles (l’épicéa et la paille de blé prétraitées de façon semblable, ont été étudiées. Différentes approches ont été tentées pour améliorer la saccharification de ces matières premières, par exemple, la recherche de nouvelles enzymes efficaces ou l’ingénierie d’enzymes. Plusieurs stratégies d’ingénierie génétique ont été utilisées pour obtenir des souches stables de Saccharomyces cerevisiae capables de fermenter le xylose et l’arabinose, et de tolérer les composés toxiques présents dans les hydrolysats lignocellulosiques. L’installation pilote pouvait traiter 2 tonnes de matières sèches par jour, et l’hydrolyse et la fermentation pouvaient être menées successivement ou simultanément. Un modèle global intégrant la chaîne d’approvisionn

Monot F.

2013-08-01

130

Affinity purification of copper chelating peptides from chickpea protein hydrolysates.  

Science.gov (United States)

Chickpea protein hydrolysates obtained with alcalase and flavourzyme were used for purification of copper chelating peptides by affinity chromatography using copper immobilized on solid supports. The chelating activity of purified peptides was indirectly measured by the inhibition of beta-carotene oxidation in the presence of copper. Two protein hydrolysates, obtained after 10 and 100 min of hydrolysis, were the most inhibitory of beta-carotene oxidation. Purified copper chelating peptides from these protein hydrolysates contained 19.7 and 35.1% histidine, respectively, in comparison to 2.7 and 2.6% in the protein hydrolysates. Chelating peptides from hydrolysate obtained after 10 min of hydrolysis were the most antioxidative being 8.3 times more antioxidative than the hydrolysate, while chelating peptides purified from protein hydrolysate obtained after 100 min were 3.1 times more antioxidative than its hydrolysate. However, the histidine content was higher in peptides derived from the 100 min hydrolysate (19.7 against 35.1% in 10 min hydrolysate), indicating that this amino acid is not the only factor involved in the antioxidative activity, and other factors such as peptide size or amino acid sequence are also determinant. This manuscript shows that affinity chromatography is a useful procedure for purification of copper chelating peptides. This method can be extended to other metals of interest in nutrition, such as calcium, iron, or zinc. Purified chelating peptides, in addition to their antioxidative properties, may also be useful in food mineral fortification for increasing the bioavailability of these metals. PMID:17428066

Megías, Cristina; Pedroche, Justo; Yust, Maria M; Girón-Calle, Julio; Alaiz, Manuel; Millan, Francisco; Vioque, Javier

2007-05-16

131

Mineral and vitamin content of beef, chicken, and turkey hydrolysates mineral and vitamin content of protein hydrolysates  

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Full Text Available The purpose of this study was to assess the concentration of vitamins and minerals in meat protein hydrolysates. Calcium, phosphorus and iron were analyzed by inductively coupled-plasma atomic emission spectrophotometry; vitamin C was analyzed by the reduction of cupric ions and vitamins B1 and B2 by fluorescence. Regarding minerals, the beef hydrolysate (BH had more iron than the turkey hydrolysate (TH and the chicken hydrolysate (CH; TH had a little more phosphorus. BH had the largest amount of vitamin C, and similar amounts of vitamins B1 and B2. The amount of these nutrients found in the hydrolysates suggests that it is possible to use them to enrich special dietary formulations.

Maria Elisabeth Machado Pinto e Silva

2008-01-01

132

Ionic liquid pretreatment of lignocellulosic biomass  

OpenAIRE

This thesis is concerned with the thermal treatment of lignocellulosic biomass using ionic liquids for the purpose of comminution via dissolution, for fractionating the biological composite and for obtaining aqueous solutions of carbohydrate monomers from the pulp via enzymatic hydrolysis. A major focus was the relationship between the choice of the anion and the effectiveness of the treatment. The synthesis of a range of 1-butyl-3-methylimidazolium ionic liquids with str...

Brandt, Agnieszka

2012-01-01

133

Hyperthermophilic endoglucanase for in planta lignocellulose conversion  

OpenAIRE

Background: The enzymatic conversion of lignocellulosic plant biomass into fermentable sugars is a crucial step in the sustainable and environmentally friendly production of biofuels. However, a major drawback of enzymes from mesophilic sources is their suboptimal activity under established pretreatment conditions, e. g. high temperatures, extreme pH values and high salt concentrations. Enzymes from extremophiles are better adapted to these conditions and could be produced by heterologous exp...

Klose, H.; Ro?der, J.; Girfoglio, M.; Fischer, R.; Commandeur, U.

2012-01-01

134

Metabolic engineering of Enterobacter cloacae for high-yield production of enantiopure (2R,3R)-2,3-butanediol from lignocellulose-derived sugars.  

Science.gov (United States)

Biotechnological production of biofuels is restricted by toxicity of the products such as ethanol and butanol. As its low toxicity to microbes, 2,3-butanediol (2,3-BD), a fuel and platform bio-chemical, could be a promising alternative for biofuel production from renewable bioresources. In addition, no bacterial strains have been reported to produce enantiopure 2,3-BD using lignocellulosic hydrolysates. In this study, Enterobacter cloacae strain SDM was systematically and metabolically engineered to construct an efficient biocatalyst for production of the fuel and enantiopure bio-chemical-(2R,3R)-2,3-BD. First, the various (2R,3R)-2,3-BD dehydrogenase encoding genes were expressed in a meso-2,3-BD dehydrogenase encoding gene disrupted E. cloacae strain under native promoter Pb of the 2,3-BD biosynthetic gene cluster of E. cloacae. Then, carbon catabolite repression was eliminated via inactivation of the glucose transporter encoding gene ptsG and overexpression of a galactose permease encoding gene galP. The resultant strain could utilize glucose and xylose simultaneously. To improve the efficiency of (2R,3R)-2,3-BD production, the byproduct-producing genes (ldh and frdA) were knocked out, thereby enhancing the yield of (2R,3R)-2,3-BD by 16.5% in 500-mL Erlenmeyer flasks. By using fed-batch fermentation in a 5-L bioreactor, 152.0g/L (2R,3R)-2,3-BD (purity>97.5%) was produced within 44h with a specific productivity of 3.5g/[Lh] and a yield of 97.7% from a mixture of glucose and xylose, two major carbohydrate components in lignocellulosic hydrolysates. In addition, when a lignocellulosic hydrolysate was used as the substrate, 119.4g/L (2R,3R)-2,3-BD (purity>96.0%) was produced within 51h with a productivity of 2.3g/[Lh] and a yield of 95.0%. These results show that the highest records have been acquired for enantiopure (2R,3R)-2,3-BD production by a native or engineered strain from biomass-derived sugars. In addition to producing the 2,3-BD, our systematic approach might also be used in the production of other important chemicals by using lignocellulose-derived sugars. PMID:25499652

Li, Lixiang; Li, Kun; Wang, Yu; Chen, Chao; Xu, Youqiang; Zhang, Lijie; Han, Binbin; Gao, Chao; Tao, Fei; Ma, Cuiqing; Xu, Ping

2015-03-01

135

Efficient production of sophorolipids by Starmerella bombicola using a corncob hydrolysate medium.  

Science.gov (United States)

Sophorolipids (SLs) are amphiphilic compounds produced from a variety of saccharides and vegetable oils by the yeast Starmerella bombicola and related strains, and they have commercial uses as detergents. In the present study, SL production was investigated using a corncob hydrolysate (CCH) medium derived from lignocellulosic feedstocks as a source of hydrophilic carbon substrates. Excess sulfuric acid concentrations during pretreatment of the corncobs increased the furfural concentrations and turned the CCH dark brown. The optimal sulfuric acid concentration was 1% (w/v), and the treated CCH, containing 45 g/l glucose, allowed the production of 33.7 g/l of SLs following 4 days of cultivation. Additional autoclaving (121°C, 20 min) inhibited SL production and cell growth by 36% and 40%, respectively. Ammonium nitrate (0.1 g-N/l) restored SL production to the autoclaved CCH. Finally, a cost-effective SL production of 49.2 g/l, with a volumetric productivity of 12.3 g/l/day, was achieved using CCH medium during batch cultivation in a jar fermentor. PMID:25240400

Konishi, Masaaki; Yoshida, Yuka; Horiuchi, Jun-ichi

2015-03-01

136

Engineering microbial surfaces to degrade lignocellulosic biomass.  

Science.gov (United States)

Renewable lignocellulosic plant biomass is a promising feedstock from which to produce biofuels, chemicals, and materials. One approach to cost-effectively exploit this resource is to use consolidating bioprocessing (CBP) microbes that directly convert lignocellulose into valuable end products. Because many promising CBP-enabling microbes are non-cellulolytic, recent work has sought to engineer them to display multi-cellulase containing minicellulosomes that hydrolyze biomass more efficiently than isolated enzymes. In this review, we discuss progress in engineering the surfaces of the model microorganisms: Bacillus subtilis, Escherichia coli, and Saccharomyces cerevisiae. We compare the distinct approaches used to display cellulases and minicellulosomes, as well as their surface enzyme densities and cellulolytic activities. Thus far, minicellulosomes have only been grafted onto the surfaces of B. subtilis and S. cerevisiae, suggesting that the absence of an outer membrane in fungi and Gram-positive bacteria may make their surfaces better suited for displaying the elaborate multi-enzyme complexes needed to efficiently degrade lignocellulose. PMID:24430239

Huang, Grace L; Anderson, Timothy D; Clubb, Robert T

2014-01-01

137

Torrefaction of non-lignocellulose biomass waste  

Energy Technology Data Exchange (ETDEWEB)

There have been major socio-economic and environmental impacts from the world's urban population overtaking the rural population in numbers. One of the impacts is that disposal of waste from densely populated urban areas has become a major concern. Sewage in urban centers must be collected centrally and disposed of appropriately. This disposal process must be ecologically sound and energy efficient. This paper presents the torrefaction of some non-lignocellulose biomass waste that was done to ascertain if this process could be as beneficial with such materials as it is with conventional lignocellulose biomass. Tests were conducted on digested and undigested sludge and on chicken litter from a municipality in Canada. The effects of the torrefaction process parameters, temperature and residence time, on torrefaction yield were analyzed. Under the same identical conditions, torrefaction of three lignocellulose biomasses, i.e. switch grass, coffee husk and wood pellet, was also carried out for reference purposes. This study uncovered a potential option for the production of composite waste pellets.

Dhungana, A. [Dalhousie University (Canada); Dutta, A. [University of Guelph (Canada); Basu, P. [Greenfield Research Incorporated (Canada)

2012-02-15

138

Plant biotechnology for lignocellulosic biofuel production.  

Science.gov (United States)

Lignocelluloses from plant cell walls are attractive resources for sustainable biofuel production. However, conversion of lignocellulose to biofuel is more expensive than other current technologies, due to the costs of chemical pretreatment and enzyme hydrolysis for cell wall deconstruction. Recalcitrance of cell walls to deconstruction has been reduced in many plant species by modifying plant cell walls through biotechnology. These results have been achieved by reducing lignin content and altering its composition and structure. Reduction of recalcitrance has also been achieved by manipulating hemicellulose biosynthesis and by overexpression of bacterial enzymes in plants to disrupt linkages in the lignin-carbohydrate complexes. These modified plants often have improved saccharification yield and higher ethanol production. Cell wall-degrading (CWD) enzymes from bacteria and fungi have been expressed at high levels in plants to increase the efficiency of saccharification compared with exogenous addition of cellulolytic enzymes. In planta expression of heat-stable CWD enzymes from bacterial thermophiles has made autohydrolysis possible. Transgenic plants can be engineered to reduce recalcitrance without any yield penalty, indicating that successful cell wall modification can be achieved without impacting cell wall integrity or plant development. A more complete understanding of cell wall formation and structure should greatly improve lignocellulosic feedstocks and reduce the cost of biofuel production. PMID:25330253

Li, Quanzi; Song, Jian; Peng, Shaobing; Wang, Jack P; Qu, Guan-Zheng; Sederoff, Ronald R; Chiang, Vincent L

2014-12-01

139

Emulsifying and emulsion-stabilizing properties of gluten hydrolysates.  

Science.gov (United States)

Gluten is produced as a coproduct of the wheat starch isolation process. In this study, gluten was hydrolyzed to degrees of hydrolysis (DH) of 3-6-10 and 1-2-3 with alcalase and trypsin, respectively. These peptidases have a clearly distinct substrate specificity. Corn oil-in-water emulsions (10 wt % oil) were prepared by high-pressure homogenization at pH 7.5. Gluten peptides with DH 3 proved to be the most effective in producing peptides displaying emulsifying properties. Higher levels of alcalase hydrolysates (2.0 wt %) than of trypsin hydrolysates (1.0 wt %) were required to produce stable emulsions with small droplet sizes, which is attributed to differences in the nature of the peptides formed. The emulsions had small mean droplet diameters (d32 hydrolysates (stable after 9 days at 55 °C) displayed better thermal stability compared to those produced with alcalase hydrolysates (destabilized after 2 days at 37 °C). The hydrolysate-containing emulsions, however, were quickly destabilized by salt addition (?100 mM NaCl) and when the pH approached the isoelectric point of the coated droplets (pH ~5.5). Microscopic analysis revealed the formation of air-in-oil-in-water emulsions at lower hydrolysate concentrations, whereas at higher concentrations (?3.0 wt %) extensive flocculation occurred. Both phenomena contributed to creaming of the emulsions. These results may be useful for the utilization of gluten hydrolysates in food and beverage products. PMID:24571632

Joye, Iris J; McClements, David J

2014-03-26

140

Can lignocellulosic hydrocarbon liquids rival lignocellulose-derived ethanol as a future transport fuel?  

Directory of Open Access Journals (Sweden)

Full Text Available Although transport fuels are currently obtained mainly from petroleum, alternative fuels derived from lignocellulosic biomass (LB have drawn much attention in recent years in light of the limited reserves of crude oil and the associated environmental issues. Lignocellulosic ethanol (LE and lignocellulosic hydrocarbons (LH are two typical representatives of the LB-derived transport fuels. This editorial systematically compares LE and LB from production to their application in transport fuels. It can be demonstrated that LH has many advantages over LE relative to such uses. However, most recent studies on the production of the LB-derived transport fuels have focused on LE production. Hence, it is strongly recommended that more research should be aimed at developing an efficient and economically viable process for industrial LH production.

Yao Ding

2012-11-01

141

Processes for converting lignocellulosics to reduced acid pyrolysis oil  

Energy Technology Data Exchange (ETDEWEB)

Processes for producing reduced acid lignocellulosic-derived pyrolysis oil are provided. In a process, lignocellulosic material is fed to a heating zone. A basic solid catalyst is delivered to the heating zone. The lignocellulosic material is pyrolyzed in the presence of the basic solid catalyst in the heating zone to create pyrolysis gases. The oxygen in the pyrolysis gases is catalytically converted to separable species in the heating zone. The pyrolysis gases are removed from the heating zone and are liquefied to form the reduced acid lignocellulosic-derived pyrolysis oil.

Kocal, Joseph Anthony; Brandvold, Timothy A

2015-01-06

142

Production of Ethanol from Cocoa Pod Hydrolysate  

Directory of Open Access Journals (Sweden)

Full Text Available Cocoa pod (Theobroma cacao L. hydrolysate was hydrolyzed into glucose using hydrochloric, sulphuric and nitric acids, respectively. The concentration of each acid was set at 0.25 M, 0.50 M, 0.75 M, 1.00 M and 1.25 M. They were treated under two different temperatures and time at 75?C and 90?C for 2 h and 4 h, respectively. The results showed that hydrolysis in 1.00 M of hydrochloric acid at 75?C for 4 h had produced the highest glucose content of 30.7% w/v compared to all others acids treated under similar conditions. The pod’s hydolysate was then fermented in batch culture using Saccharomyces cerevisiae for 48 h at 30?C. A maximum ethanol production of 17.3%v/v was achieved after 26 h of fermentation time.

Othman Abd Samah

2011-07-01

143

The identity of lunar hydrolysable carbon  

International Nuclear Information System (INIS)

It is stated that luner soils treated with deuterated acid release a variety of deuterocarbon gases, including CD4, C2D6, C2D4, C2D2 and C3 species. It is here suggested that the principal hydrolysable C phase in lunar samples is C in solid solution in ?-Fe, and the yield of deuterocarbons from the lunar soil is probably a quantitative estimate of this carbon. Synthetic alloys of C in ?-Fe, together with some samples of cementite (Fe3C), prepared by reduction of pure Fe203 in mixtures of C0 and C02, were treated with DCl and the gases released were analysed by gas chromatography. The yields of deuterocarbons were low in samples containing cementite, whereas the ?-Fe samples released considerable quantities the largest amounts being evolved from specimens prepared under conditions of high C solubility. From the results it is concluded that iron carbides are unlikely to be the hydrolysable phase in lunar soils, and C in solid solution in Fe, probably associated with ?-Fe, is a more likely candidate. The concentration of C in the ?-Fe in lunar material can be calculated as 0.27 to 0.77 wt.%, values that are in excess of the solid solubility limits. It is stated that of the mechanisms that have been suggested for the formation of metallic Fe in lunar soils only preferential sputtering by the solar wind has been shown to be both theoreticd has been shown to be both theoretically and practically possible, and ways in which C could form solid solutions in surface layers of ?-Fe produced by sputtering are discussed. Direct implantation of solar wind C into the metal could produce solid solutions in excess of solubility limits. (U.K.)

144

Quantification of solubilized hemicellulose from pretreated lignocellulose by acid hydrolysis and high-performance liquid chromatography  

Energy Technology Data Exchange (ETDEWEB)

An investigation of the acid hydrolysis and HPLC analysis have been carried out in order to optimise the quantification of the solubilized hemicellulose fraction from wheat straw lignocellulose after pretreatment. Different acid hydrolyses have been performed to identify which conditions (concentrations of acid and hydrolysis time) gave the maximal quantification of the solubilized hemicellulose (measured as monosaccharides). Four different sugars were identified: xylose, arabinose, glucose and galactose. Some hydrolyses were carried out on aqueous samples and some using freeze-dried samples. The best overall hydrolysis was obtained by treatment of an aqueous sample with 4 %w/v sulfuric acid for 10 minutes. These conditions were not optimal for the determination of glucose, which was estimated by using a correction factor. A purification step was needed following the acid hydrolysis, and included a sulfate precipitation by barium hydroxide and elimination of remaining ions by mixed-bed ion exchange. The level of barium hydroxide addition significantly reduced the recovery of the sugars. Thus, lower than equivalent amounts of barium hydroxide were added in the purification step. For monosaccharide analysis two different HPLC columns, i.e. Aminex HPX-87P and HPX-87H with different resin ionic forms, lead (Pb{sup 2+}) and hydrogen (H{sup +}), respectively. The lead column (HPX-87P) separated all four sugars in the acid hydrolyzates, but sample purification required the removal of all interfering impurities, which resulted in poor reproducibility and a sugar recovery below 50%. The hydrogen column (HPX-87H) separated only glucose, xylose and arabinose, whereas galactose was not separated from xylose; however, the column was less sensitive towards impurities and gave improved recovery and reproducibility. Therefore, the hydrogen column (HPX-87H) was chosen for routine quantification of the hydrolyzed hemicellulose sugars. (au) 11 tabs., 8 ills., 19 refs.

Bjerre, A.B.; Ploeger, A.; Simonsen, T.; Woidemann, A.; Schmidt, A.S.

1996-11-01

145

Bacterial biodegradation and bioconversion of industrial lignocellulosic streams.  

Science.gov (United States)

Lignocellulose is a term for plant materials that are composed of matrices of cellulose, hemicellulose, and lignin. Lignocellulose is a renewable feedstock for many industries. Lignocellulosic materials are used for the production of paper, fuels, and chemicals. Typically, industry focuses on transforming the polysaccharides present in lignocellulose into products resulting in the incomplete use of this resource. The materials that are not completely used make up the underutilized streams of materials that contain cellulose, hemicellulose, and lignin. These underutilized streams have potential for conversion into valuable products. Treatment of these lignocellulosic streams with bacteria, which specifically degrade lignocellulose through the action of enzymes, offers a low-energy and low-cost method for biodegradation and bioconversion. This review describes lignocellulosic streams and summarizes different aspects of biological treatments including the bacteria isolated from lignocellulose-containing environments and enzymes which may be used for bioconversion. The chemicals produced during bioconversion can be used for a variety of products including adhesives, plastics, resins, food additives, and petrochemical replacements. PMID:25722022

Mathews, Stephanie L; Pawlak, Joel; Grunden, Amy M

2015-04-01

146

SOIL FUNGI: POTENTIAL MYCOREMEDIATORS OF LIGNOCELLULOSIC WASTE  

Directory of Open Access Journals (Sweden)

Full Text Available The continual expansion of urbanization and industrial activity has led to the accumulation of a large quantity of lignocellulosic residues throughout the world. In particular, large quantities of paper and bagasse are largely produced in Visakhapatnam. In this work we present the study of the degradability of these substrates with fungi. Three cultures of soil fungi were screened for their ability to degrade cellulose. Aspergillus flavus degraded the most, as shown by the highest CO2 release. Further, Aspergillus flavus was tested with the standard fungus Phanerochaete chrysosporium for cellulose degradation, which showed nearly equivalent potential.

Y. Avasn Maruthi

2010-05-01

147

Comparison of different pretreatment methods for separation hemicellulose from straw during the lignocellulosic bioethanol production  

Science.gov (United States)

The combustion of fossil fuels is responsible for 73% of carbon dioxide emissions into the atmosphere and consequently contributes to global warming. This fact has enormously increased the interest in the development of methods to reduce greenhouse gases. Therefore, the focus is on the production of biofuels from lignocellulosic agricultural residues. The feedstocks used for 2nd generation bioethanol production are lignocellulosic raw materials like different straw types or energy crops like miscanthus sinensis or arundo donax. Lignocellulose consists of hemicellulose (xylose and arabinose), which is bonded to cellulose (glucose) and lignin. Prior to an enzymatic hydrolysis of the polysaccharides and fermentation of the resulting sugars, the lignocelluloses must be pretreated to make the sugar polymers accessible to enzymes. A variety of pretreatment methods are described in the literature: thermophysical, acid-based and alkaline methods.In this study, we examined and compared the most important pretreatment methods: Steam explosion versus acid and alkaline pretreatment. Specific attention was paid to the mass balance, the recovery of C 5 sugars and consumption of chemicals needed for pretreatment. In lab scale experiments, wheat straw was either directly pretreated by steam explosion or by two different protocols. The straw was either soaked in sulfuric acid or in sodium hydroxide solution at different concentrations. For both methods, wheat straw was pretreated at 100°C for 30 minutes. Afterwards, the remaining straw was separated by vacuum filtration from the liquid fraction.The pretreated straw was neutralized, dried and enzymatically hydrolyzed. Finally, the sugar concentrations (glucose, xylose and arabinose) from filtrate and from hydrolysate were determined by HPLC. The recovery of xylose from hemicellulose was about 50% using the sulfuric acid pretreatment and less than 2% using the sodium hydroxide pretreatment. Increasing concentrations of sulfuric acid lead to increasing conversion of hemicellulose to xylose. In contrast, increasing sodium hydroxide concentrations degrade the hemicellulose to unknown derivates. Consequently, almost no sugars from hemicellulose remain for fermentation. The hydrolysis of sulfuric acid pretreated straw results in a maximum glucose concentration of 100 g/kg straw and a xylose concentration of nearly 30 g/kg. Sodium hydroxide pretreated and hydrolyzed straw leads to a maximum glucose concentration of 90 g/kg straw and a xylose concentration of nearly 20 g/kg. In comparison to the two chemical pretreatment methods (sodium hydroxide and sulfuric acid pretreatment), the steam explosion pretreatment (conditions: temperature 190°C, time 20 minutes) results in a higher glucose concentration of about 190 g/kg straw and a xylose concentration of nearly 75 g/kg straw after enzymatic hydrolysis of the dried straw. Because of the small effect the sodium hydroxide pretreatment has on xylose recovery, this method won't be used for separation and conversion of hemicellulose into xylose and arabinose. Although pretreatment with sulfuric acid achieved promising results, further research and economical considerations have to be performed. In conclusion, the steam explosion method is still the state of the art pretreatment method for the production of lignocellulosic biofuels. Alkaline methods destroy most of the xylose part of the sugar fraction and a loss of up to 25 % of the fermentable sugars is not acceptable for a sustainable biofuel production. The acid pretreatment yields high amounts of accessible hemicellulose and cellulose, but the consumption of chemicals for acid pretreatment and neutralization has to be taken into account when considering technical implementation.

Eisenhuber, Katharina; Krennhuber, Klaus; Steinmüller, Viktoria; Kahr, Heike; Jäger, Alexander

2013-04-01

148

BIOCONVERSION OF WATER HYACINTH HYDROLYSATE INTO ETHANOL  

Directory of Open Access Journals (Sweden)

Full Text Available The fast growing aquatic weed water hyacinth, which is available almost year-round in the tropics and subtropics, was utilized as the chief source of cellulose for production of fuel ethanol via enzymatic hydrolysis and fermentation. Fungal cellulases produced on-site by utilizing acid-alkali pretreated water hyacinth as the substrate were used as the crude enzyme source for hydrolysis of identically pretreated biomass. Four different modes of enzymatic hydrolysis and fermentation were trialed in the present study for optimization of the yield of ethanol. Two common yeasts viz., Saccharomyces cerevisiae and Pachysolen tannophilus, were used for fermentation of hexose and pentose sugars in the hydrolysate. Significant enhancement of concentration (8.3 g/L and yield (0.21 g/g of ethanol was obtained through a prefermentation hydrolysis-simultaneous saccharification and fermentation (PH-SSF process, over the other three processes viz., separate hydrolysis and fermentation (SHF, simultaneous saccharification and fermentation (SSF, and single batch bioconversion (SBB by utilizing fungal culture broth with and without filtration as crude enzyme source.

Sunita Bandopadhyay Mukhopadhyay

2010-04-01

149

Pork fat hydrolysed by Staphylococcus xylosus  

DEFF Research Database (Denmark)

Staphylococcus xylosus is used as a starter culture in the production of fermented sausages. Its ability to hydrolyse pork fat was investigated. Within 15 days of incubation an interaction of bacterial growth, lipase production and lipase activity in a pork fat containing medium caused liberation of fatty acids. The free fatty acids were determined both qualitatively and quantitatively. The effects of incubtion temperature and pH were studied using Response Surface Methodology. Within the area of interest for the producion of fermented sausages, no local maximum or minimum liberation of fatty acids was found. A rise in pH increased the amount of free fatty acids. Below pH 5.0, the amount of liberated fatty acids was insignificant although the viable count was >10+6 cell/ g emulsion. Of the two factors, pH was most influential in affecting the amount of free fatty acids. A rise in temperaure only slightly increased the amount of free fatty acids and hydrolysis took place at all temperatures from 14°C to 27°C. The strain liberates the fatty acids in a nonspecific way, in about the same proportions as those in which they occur in the pork fat.

SØrensen, B. B.; Stahnke, Louise Heller

1993-01-01

150

Removal and upgrading of lignocellulosic fermentation inhibitors by in situ biocatalysis and liquid-liquid extraction.  

Science.gov (United States)

Hydroxycinnamic acids are known to inhibit microbial growth during fermentation of lignocellulosic biomass hydrolysates, and the ability to diminish hydroxycinnamic acid toxicity would allow for more effective biological conversion of biomass to fuels and other value-added products. In this work, we provide a proof-of-concept of an in situ approach to remove these fermentation inhibitors through constituent expression of a phenolic acid decarboxylase combined with liquid-liquid extraction of the vinyl phenol products. As a first step, we confirmed using simulated fermentation conditions in two model organisms, Escherichia coli and Saccharomyces cerevisiae, that the product 4-vinyl guaiacol is more inhibitory to growth than ferulic acid. Partition coefficients of ferulic acid, p-coumaric acid, 4-vinyl guaiacol, and 4-ethyl phenol were measured for long-chain primary alcohols and alkanes, and tetradecane was identified as a co-solvent that can preferentially extract vinyl phenols relative to the acid parent and additionally had no effect on microbial growth rates or ethanol yields. Finally, E. coli expressing an active phenolic acid decarboxylase retained near maximum anaerobic growth rates in the presence of ferulic acid if and only if tetradecane was added to the fermentation broth. This work confirms the feasibility of donating catabolic pathways into fermentative microorganisms in order to ameliorate the effects of hydroxycinnamic acids on growth rates, and suggests a general strategy of detoxification by simultaneous biological conversion and extraction. PMID:25311910

Tomek, Kyle J; Saldarriaga, Carlos Rafael Castillo; Velasquez, Fernando Peregrino Cordoba; Liu, Tongjun; Hodge, David B; Whitehead, Timothy A

2015-03-01

151

Enzymology of lignocellulose bioconversion by Streptomyces viridosporus  

International Nuclear Information System (INIS)

Significant progress has been made in lignin biodegradation research since 1983, when lignin peroxidases were discovered in fungi. A similar breakthrough in bacterial lignin biodegradation research is anticipated. Several laboratories have successfully demonstrated the ability of bacteria to mineralize [14C]-lignin lignocelluloses as well as 14C-labelled synthetic lignins. Attempts are being made to identify the key enzymes involved. In this dissertation, two studies are presented which address the enzymology of lignin biodegradation by Streptomyces viridosporus. The first study compares selected extracellular enzyme of wild-type and genetically manipulated strains with enhanced abilities to produced a water soluble lignin degradation intermediate, designated acid-precipitable polymeric lignin (APPL). UV irradiation mutant T7A-81 and protoplast fusion recombinant SR-10 had higher and longer persisting peroxidase, esterase, and endoglucanase activity than did the wild type strain T7A. An extracellular lignocellulose-induced peroxidase with some similarities to fungal ligninases was described for the first time in Streptomyces. The second study describes purification and characterization of an extracellular lignin peroxidase produced by S. viridosporus T7A. This is the first report of a lignin peroxidase in any bacterium

152

Reviving the carbohydrate economy via multi-product lignocellulose biorefineries.  

Science.gov (United States)

Before the industrial revolution, the global economy was largely based on living carbon from plants. Now the economy is mainly dependent on fossil fuels (dead carbon). Biomass is the only sustainable bioresource that can provide sufficient transportation fuels and renewable materials at the same time. Cellulosic ethanol production from less costly and most abundant lignocellulose is confronted with three main obstacles: (1) high processing costs (dollars /gallon of ethanol), (2) huge capital investment (dollars approximately 4-10/gallon of annual ethanol production capacity), and (3) a narrow margin between feedstock and product prices. Both lignocellulose fractionation technology and effective co-utilization of acetic acid, lignin and hemicellulose will be vital to the realization of profitable lignocellulose biorefineries, since co-product revenues would increase the margin up to 6.2-fold, where all purified lignocellulose co-components have higher selling prices (> approximately 1.0/kg) than ethanol ( approximately 0.5/kg of ethanol). Isolation of large amounts of lignocellulose components through lignocellulose fractionation would stimulate R&D in lignin and hemicellulose applications, as well as promote new markets for lignin- and hemicellulose-derivative products. Lignocellulose resource would be sufficient to replace significant fractionations (e.g., 30%) of transportation fuels through liquid biofuels, internal combustion engines in the short term, and would provide 100% transportation fuels by sugar-hydrogen-fuel cell systems in the long term. PMID:18180967

Zhang, Y-H Percival

2008-05-01

153

Oconee spent fuel rerack  

International Nuclear Information System (INIS)

Spent fuel storage problems facing electric utilities with nuclear generation are growing more critical as existing spent fuel storage capacity is utilized. Due to the inaccessibility of spent fuel reprocessing plants, alternative temporary solutions such as transfer of spent nuclear fuel to other storage facilities and increasing the capacity of existing storage facilities through reracking are becoming increasingly prevalent. This paper describes the method and installation of new racks for increasing the fuel storage capacity of unit 3 of Duke Power Company's Oconee Nuclear Station near Seneca, South Carolina

154

Detoxification of acidic catalyzed hydrolysate of Kappaphycus alvarezii (cottonii).  

Science.gov (United States)

Red seaweed, Kappaphycus alvarezii, holds great promise for use in biofuel production due to its high carbohydrate content. In this study, we investigated the effect of fermentation inhibitors to the K. alvarezii hydrolysate on cell growth and ethanol fermentation. In addition, detoxification of fermentation inhibitors was performed to decrease the fermentation inhibitory effect. 5-Hydroxymethylfurfural and levulinic acid, which are liberated from acidic hydrolysis, was also observed in the hydrolysate of K. alvarezii. These compounds inhibited ethanol fermentation. In order to remove these inhibitors, activated charcoal and calcium hydroxide were introduced. The efficiency of activated charcoals was examined and over-liming was used to remove the inhibitors. Activated charcoal was found to be more effective than calcium hydroxide to remove the inhibitors. Detoxification by activated charcoal strongly improved the fermentability of dilute acid hydrolysate in the production of bioethanol from K. alvarezii with Saccharomyces cerevisiae. The optimal detoxifying conditions were found to be below an activated charcoal concentration of 5%. PMID:21909671

Meinita, Maria Dyah Nur; Hong, Yong-Ki; Jeong, Gwi-Taek

2012-01-01

155

Production of enzymatic protein hydrolysates from freshwater catfish (Clarias batrachus)  

Science.gov (United States)

Fish protein hydrolysate (FPH) was prepared from freshwater catfish (Clarias batrachus) by using Alcalase® 2.4L and Papain. The effect of hydrolysis time (30, 60, 120, 180 min) with enzyme concentration of 1% (v/w substrate); pH = 8.0, 7.0 was studied to determine the degree of hydrolysis (DH), peptide content, proximate composition and amino acid profile. Results showed that the highest DH of Alcalase and Papain FPH were 58.79% and 53.48% after 180 min at 55°C incubation respectively. The peptide content of both FPH increased as hydrolysis time increases. FPH showed higher crude protein content and lower fat, moisture and ash content compared to raw catfish. The major amino acids of both hydrolysates were Glu, Lys and Asp. Content of essential amino acids of Alcalase and Papain hydrolysates were 44.05% and 43.31% respectively.

Seniman, Maizatul Sarah Md; Yusop, Salma Mohamad; Babji, Abdul Salam

2014-09-01

156

Impedance of nickel/cadmium cells with nylon separator hydrolysate  

Energy Technology Data Exchange (ETDEWEB)

In sealed nickel/cadmium cells, degradation of the nylon separator leads to decrease in the electrolyte and, eventually, to shorting of the cells. To understand this effect further, a study of the influence of nylon hydrolysis on the impedance of nickel/cadmium cells has been undertaken. Measurements have been made of the impedance of a positive-limited nickel/cadmium cell (flooded type) with and without nylon hydrolysate. The nylon hydrolysate was expected to affect the double-layer impedance of the nickel oxide electrode around a cell voltage of 0.4 V. Unfortunately, the results show only small changes in the cell impedance due to nylon hydrolysate and these are not considered to be significant. It appears, therefore, that the impedance technique does not provide unequivocal information about nylon hydrolysis. (orig.)

Suresh, M.S. (Battery Div., ISRO Satellite Centre, Bangalore (India))

1994-07-01

157

Superhydrophobic lignocellulosic wood fiber/mineral networks.  

Science.gov (United States)

Lignocellulosic wood fibers and mineral fillers (calcium carbonate, talc, or clay) were used to prepare paper samples (handsheets), which were then subjected to a fluorocarbon plasma treatment. The plasma treatment was performed in two steps: first using oxygen plasma to create nanoscale roughness on the surface of the handsheet, and second fluorocarbon deposition plasma to add a layer of low surface energy material. The wetting behavior of the resulting fiber/mineral network (handsheet) was determined. It was found the samples that were subjected to oxygen plasma etching prior to fluorocarbon deposition exhibit superhydrophobicity with low contact angle hysteresis. On the other hand, those that were only treated by fluorocarbon plasma resulted in "sticky" hydrophobicity behavior. Moreover, as the mineral content in the handsheet increases, the hydrophobicity after plasma treatment decreases. Finally, it was found that although the plasma-treated handsheets show excellent water repellency they are not good water vapor barriers. PMID:23957774

Mirvakili, Mehr Negar; Hatzikiriakos, Savvas G; Englezos, Peter

2013-09-25

158

Tower reactors for bioconversion of lignocellulosic material  

Science.gov (United States)

An apparatus for enzymatic hydrolysis and fermentation of pretreated lignocellulosic material, in the form of a tower bioreactor, having mixers to achieve intermittent mixing of the material. Precise mixing of the material is important for effective heat and mass transfer requirements without damaging or denaturing the enzymes or fermenting microorganisms. The pretreated material, generally in the form of a slurry, is pumped through the bioreactor, either upwards or downwards, and is mixed periodically as it passes through the mixing zones where the mixers are located. For a thin slurry, alternate mixing can be achieved by a pumping loop which also serves as a heat transfer device. Additional heat transfer takes place through the reactor heat transfer jackets.

Nguyen, Quang A. (16458 W. 1st Ave., Golden, CO 80401)

1999-01-01

159

Tower reactors for bioconversion of lignocellulosic material  

Science.gov (United States)

An apparatus is described for enzymatic hydrolysis and fermentation of pretreated lignocellulosic material, in the form of a tower bioreactor, having mixers to achieve intermittent mixing of the material. Precise mixing of the material is important for effective heat and mass transfer requirements without damaging or denaturing the enzymes or fermenting microorganisms. The pretreated material, generally in the form of a slurry, is pumped through the bioreactor, either upwards or downwards, and is mixed periodically as it passes through the mixing zones where the mixers are located. For a thin slurry, alternate mixing can be achieved by a pumping loop which also serves as a heat transfer device. Additional heat transfer takes place through the reactor heat transfer jackets. 5 figs.

Nguyen, Q.A.

1999-03-30

160

Extrusion Pretreatment of Lignocellulosic Biomass: A Review  

Directory of Open Access Journals (Sweden)

Full Text Available Bioconversion of lignocellulosic biomass to bioethanol has shown environmental, economic and energetic advantages in comparison to bioethanol produced from sugar or starch. However, the pretreatment process for increasing the enzymatic accessibility and improving the digestibility of cellulose is hindered by many physical-chemical, structural and compositional factors, which make these materials difficult to be used as feedstocks for ethanol production. A wide range of pretreatment methods has been developed to alter or remove structural and compositional impediments to (enzymatic hydrolysis over the last few decades; however, only a few of them can be used at commercial scale due to economic feasibility. This paper will give an overview of extrusion pretreatment for bioethanol production with a special focus on twin-screw extruders. An economic assessment of this pretreatment is also discussed to determine its feasibility for future industrial cellulosic ethanol plant designs.

Jun Zheng

2014-10-01

161

Lignocellulose-degrading enzymes from termites and their symbiotic microbiota.  

Science.gov (United States)

Lignocellulose-the dry matter of plants, or "plant biomass"-digestion is of increasing interest in organismal metabolism research, specifically the conversion of biomass into biofuels. Termites efficiently decompose lignocelluloses, and studies on lignocellulolytic systems may elucidate mechanisms of efficient lignocellulose degradation in termites as well as offer novel enzyme sources, findings which have significant potential industrial applications. Recent progress in metagenomic and metatranscriptomic research has illuminated the diversity of lignocellulolytic enzymes within the termite gut. Here, we review state-of-the-art research on lignocellulose-degrading systems in termites, specifically cellulases, xylanases, and lignin modification enzymes produced by termites and their symbiotic microbiota. We also discuss recent investigations into heterologous overexpression of lignocellulolytic enzymes from termites and their symbionts. PMID:23623853

Ni, Jinfeng; Tokuda, Gaku

2013-11-01

162

Antioxidant and functional properties of protein hydrolysates from pink perch (Nemipterus japonicus) muscle  

OpenAIRE

Functional properties and antioxidant activity of pink perch (Nemipterus japonicus) muscle hydrolysed by three different enzymes papain, pepsin and trypsin were studied. The protein hydrolysates produced by trypsin had an excellent solubility (98%) compared to pepsin (77%) and papain hydrolysate (74%). Conversely, the emulsifying activity index (ESI) and foaming abilities were affected by pH. DPPH radical scavenging ability, reducing power and metal chelating activity of protein hydrolysates ...

Naqash, Shabeena Yousuf; Nazeer, R. A.

2011-01-01

163

Electricity generation by microbial fuel cells fuelled with wheat straw hydrolysate  

OpenAIRE

Electricity production from microbial fuel cells fueled with hydrolysate produced by hydrothermal treatment of wheat straw can achieve both energy production and domestic wastewater purification. The hydrolysate contained mainly xylan, carboxylic acids, and phenolic compounds. Power generation and substrate utilization from the hydrolysate was compared with the ones obtained by defined synthetic substrates. The power density increased from 47 mW m?2 to 148 mW m?2 with the hydrolysate:wast...

Thygesen, Anders; Poulsen, Finn Willy; Angelidaki, Irini; Min, Booki; Thomsen, Anne Belinda

2011-01-01

164

Factors affecting antioxidant activity of soybean meal and caseine protein hydrolysates  

International Nuclear Information System (INIS)

Antioxidative activity of protein hydrolysates was dependent on the raw material, condition of hydrolysis and lipid substrate used in model systems. Soybean meal hydrolysate was more active in lard and in linoleic acid emulsion than caseine hydrolysate, whereas caseine was more active in vegetable oils. Antioxidant activity of evaluated protein hydrolysates in all lipid systems, with or without oxidation catalysts, suggests them as natural food additives for lipid stabilization, thus for improvement of its nutritional value and sensory properties

165

FTIR spectra of whey and casein hydrolysates in relation to their functional properties  

OpenAIRE

Mid-infrared spectra of whey and casein hydrolysates were recorded using Fourier transform infrared (FTIR) spectroscopy. Multivariate data analysis techniques were used to investigate the capacity of FTIR spectra to classify hydrolysates and to study the ability of the spectra to predict bitterness, solubility, emulsifying, and foaming properties of hydrolysates. Principal component analysis revealed that hydrolysates prepared from different protein sources or with different classes of proteo...

Ven, C.; Muresan, S.; Gruppen, H.; Bont, D. B. A.; Merck, K. B.; Voragen, A. G. J.

2002-01-01

166

Enzymatic Pretreatment of Lignocellulose Rich Waste for Improved Biogas Production  

OpenAIRE

The present study aimed to investigate the methane yield from anaerobic digestion of a lignocellulosic substrate subjected to different pretreatments. The lignocellulosic forest residues materials were milled and then pretreated with the organic solvent NMMO (N-Methylmorpholine N-oxide) and/or the lignolytic enzymes laccase and versatile peroxidase at a dosage of 60 U g-1 total solids (TS) substrate. The amount of methane produced was studied in a biomethane potential assay with inocula from ...

Kvillborn, Carin

2013-01-01

167

Multiple Levels of Synergistic Collaboration in Termite Lignocellulose Digestion  

OpenAIRE

In addition to evolving eusocial lifestyles, two equally fascinating aspects of termite biology are their mutualistic relationships with gut symbionts and their use of lignocellulose as a primary nutrition source. Termites are also considered excellent model systems for studying the production of bioethanol and renewable bioenergy from 2nd generation (non-food) feedstocks. While the idea that gut symbionts are the sole contributors to termite lignocellulose digestion has remained popular and ...

Scharf, Michael E.

2011-01-01

168

Enzymatic lignocellulose hydrolysis: Improved cellulase productivity by insoluble solids recycling  

OpenAIRE

Abstract Background It is necessary to develop efficient methods to produce renewable fuels from lignocellulosic biomass. One of the main challenges to the industrialization of lignocellulose conversion processes is the large amount of cellulase enzymes used for the hydrolysis of cellulose. One method for decreasing the amount of enzyme used is to recycle the enzymes. In this study, the recycle of enzymes associated with the insoluble solid fraction after the enzymatic hydrolysis of cellulose...

Weiss Noah; Börjesson Johan; Pedersen Lars Saaby; Meyer Anne S

2013-01-01

169

Recent Developments in the Bioconversion of Lignocelluloses into Ethanol  

OpenAIRE

Ethanol has been commercially produced using sugars derived from sugarcane and corn. Recently, research has been focused on the development of thermotolerant and ethanol-tolerant yeast or bacteria that are able to produce ethanol efficiently, as well as the development of lignocellulosic materials as the carbon sources of fermentation. Utilization of lignocellulosic materials as fermentation substrate is promising since they are available in large amounts, renewable and relatively cheap. A li...

KOESNANDAR; IS HELIANTI; NIKNIK NURHAYATI

2008-01-01

170

Spent fuel transporting cask  

International Nuclear Information System (INIS)

Purpose: To lower the degree of exposure of workers to radiation during the transport of spent fuel and also to improve transport efficiency by increasing the spent fuel holding capacity of the container. Method: A deplated uranium metal is interposed as a gamma ray shielding body between the inner and outer tubes of the shell of the spent fuel transport cask for the purpose of lessening the degree of exposure of workers to radiation by utilizing the excellent gamma ray shielding performance of the depleted uranium metal. Furthermore, the wall thickness of the whole container can be made thinner than casks in conventional use. Therefore, the cask capacity for holding the spent fuel can be increased and the transport efficiency improved. In addition, a large volume of depleted uranium metal is produced in the process of manufacturing fuel to be used for atomic power generation and in the process of re-processing the spent fuel, and can be effectively utilized. (Takahashi, M.)

171

Evaluation of sorghum straw hemicellulosic hydrolysate for biotechnological production of xylitol by Candida guilliermondii  

OpenAIRE

A preliminary study on xylitol production by Candida guilliermondii in sorghum straw hemicellulosic hydrolysate was performed. Hydrolysate had high xylose content and inhibitors concentrations did not exceed the commonly found values in other hemicellulosic hydrolysates. The highest xylitol yield (0.44 g/g) and productivity (0.19 g/Lh) were verified after 72 hours.

Sene, L.; Arruda, P. V.; Oliveira, S. M. M.; Felipe, M. G. A.

2011-01-01

172

Cellulase-lignin interactions in the enzymatic hydrolysis of lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

Today, the production of transportation fuels and chemicals is heavily dependent on fossil carbon sources, such as oil and natural gas. Their limited availability and the environmental concerns arising from their use have driven the search for renewable alternatives. Lignocellulosic plant biomass is the most abundant, but currently underutilised, renewable carbon-rich resource for fuel and chemical production. Enzymatic degradation of structural polysaccharides in lignocellulose produces soluble carbohydrates that serve as ideal precursors for the production of a vast amount of different chemical compounds. The difficulty in full exploitation of lignocellulose for fuel and chemical production lies in the complex and recalcitrant structure of the raw material. Lignocellulose is mainly composed of structural polysaccharides, cellulose and hemicellulose, but also of lignin, which is an aromatic polymer. Enzymatic degradation of cellulose and hemicellulose is restricted by several substrate- and enzyme-related factors, among which lignin is considered as one of the most problematic issues. Lignin restricts the action of hydrolytic enzymes and enzyme binding onto lignin has been identified as a major inhibitory mechanism preventing efficient hydrolysis of lignocellulosic feedstocks. In this thesis, the interactions between cellulase enzymes and lignin-rich compounds were studied in detail and the findings reported in this work have the potential to help in controlling the harmful cellulase-lignin interactions, and thus improve the biochemical processing route from lignocellulose to fuels and chemicals.

Rahikainen, J.

2013-11-01

173

Spent nuclear fuel storage  

International Nuclear Information System (INIS)

When a country becomes self-sufficient in part of the nuclear cycle, as production of fuel that will be used in nuclear power plants for energy generation, it is necessary to pay attention for the best method of storing the spent fuel. Temporary storage of spent nuclear fuel is a necessary practice and is applied nowadays all over the world, so much in countries that have not been defined their plan for a definitive repository, as well for those that already put in practice such storage form. There are two main aspects that involve the spent fuels: one regarding the spent nuclear fuel storage intended to reprocessing and the other in which the spent fuel will be sent for final deposition when the definitive place is defined, correctly located, appropriately characterized as to several technical aspects, and licentiate. This last aspect can involve decades of studies because of the technical and normative definitions at a given country. In Brazil, the interest is linked with the storage of spent fuels that will not be reprocessed. This work analyses possible types of storage, the international panorama and a proposal for future construction of a spent nuclear fuel temporary storage place in the country. (author)

174

Generation and identification of angiotensin converting enzyme (ACE) inhibitory peptides from a brewers' spent grain protein isolate.  

Science.gov (United States)

An alkaline extracted brewers' spent grain protein-enriched isolate (BSG-PI) was hydrolysed using Alcalase, Corolase PP, Flavourzyme and Promod 144MG, yielding Alc hydrolysate (H), CorH, FlavH and ProH, respectively. The degree of hydrolysis (DH) of the protein hydrolysates varied from 4.45% for ProH to 16.4% for CorH. The in vitro ACE inhibitory activity of the BSG-PI increased significantly following 15min incubations with Alcalase, Corolase PP and Flavourzyme. The 5kDa ultrafiltration permeates of FlavH and CorH resulted in lower ACE IC50 values than their respective hydrolysates. The bioactivity of the BSG-PI hydrolysates was retained after simulated gastrointestinal digestion (SGID) while SGID also resulted in the release of ACE inhibitory peptides from the BSG-PI and ProH. UPLC-MS/MS analysis resulted in the identification of 34 peptides. Of 12 synthesised peptides, IVY and ILDL were the most potent, having ACE IC50 values at 80.4±11.9 and 96.4±8.36?M, respectively. PMID:25624207

Connolly, Alan; O'Keeffe, Martina B; Piggott, Charles O; Nongonierma, Alice B; FitzGerald, Richard J

2015-06-01

175

Debittering of Protein Hydrolysates by Lactobacillus LBL-4 Aminopeptidase.  

Science.gov (United States)

Yoghurt strain Lactobacillus LBL-4 cultivated for 8-10?h at pH ~6.0 was investigated as a considerable food-grade source of intracellular aminopeptidase. Cell-free extract manifesting >200?AP U/l was obtained from cells harvested from 1?L culture media. Subtilisin-induced hydrolysates of casein, soybean isolate, and Scenedesmus cell protein with degree of hydrolysis 20-22% incubated at 45°C for 10?h by 10 AP?U/g peptides caused an enlarging of DH up to 40-42%, 46-48%, and 38-40% respectively. The DH increased rapidly during the first 4?h, but gel chromatography studies on BioGel P-2 showed significant changes occurred during 4-10?h of enzyme action when the DH increased gradually. After the digestion, the remained AP activity can be recovered by ultrafiltration (yield 40-50%). Scenedesmus protein hydrolysate with DH 20% was inoculated by Lactobacillus LBL-4 cells, and after 72?h cultivation the DH reached 32%. The protein hydrolysates (DH above 40%) obtained from casein and soybean isolate (high Q value) demonstrated a negligible bitterness while Scenedesmus protein hydrolysates (low Q value) after both treatments were free of bitterness. PMID:21876793

Tchorbanov, Bozhidar; Marinova, Margarita; Grozeva, Lydia

2011-01-01

176

Biochemical and radical-scavenging properties of sea cucumber (Stichopus vastus) collagen hydrolysates.  

Science.gov (United States)

The molecular mass distribution, amino acid composition and radical-scavenging activity of collagen hydrolysates prepared from collagen isolated from the sea cucumber Stichopus vastus were investigated. ? and ?1 chains of the collagen were successfully hydrolysed by trypsin. The molecular mass distribution of the hydrolysates ranged from 5 to 25 kDa, and they were rich in glycine, alanine, glutamate, proline and hydroxyproline residues. The hydrolysates exhibited excellent radical-scavenging activity. These results indicate that collagen hydrolysates from S. vastus can be used as a functional ingredient in food and nutraceutical products. PMID:24670209

Abedin, Md Zainul; Karim, Alias A; Latiff, Aishah A; Gan, Chee-Yuen; Ghazali, Farid Che; Barzideh, Zoha; Ferdosh, Sahena; Akanda, Md Jahurul Haque; Zzaman, Wahidu; Karim, Md Rezaul; Sarker, Md Zaidul Islam

2014-01-01

177

Sustainable Process Design of Lignocellulose based Biofuel  

DEFF Research Database (Denmark)

Worldwide energy demand has increased steadily as the world population has grown and more countries have become industrialized. The major energy sources of the world still depend on fossil fuels, which are also the main sources for carbon dioxide emission. As the fossil fuels always pass through a combustion processing step, carbondioxide and other important greenhouse gases are released. This is considered non-renewable and non-sustainable energy and may be one of the major causes of global warming and therefore, climate change concerns coupled with high oil prices. This isdriving efforts to increase the production and use of alternative and sustainable energy sources as rapidly as possible. Biofuel is a type of alternative energy that can be produced from many sources including sugar substances (such as sugarcane juice and molasses), starchy materials (such as corn and cassava), and lignocellulosic materials such as agricultural residual, straw and wood chips, the residual from wood industry. However, thosesugar and starchy materials can be used not only to make biofuels but they are also food sources. Thus, lignocellulosic materials are interesting feed-stocls as they are inexpensive, abundantly available, and are also non-food crops. In this respect, Cassava rhizome has several characteristics that make it a potential feedstock for fuel ethanol production. It has high content of cellulose and hemicelluloses . The objective of this paper is to present a study focused on the sustainable process design of bioethanol production from cassava rhizome using various computer aided tools through a systematic and effiicient work-flow, The study includes process simulation, sustainability analysis, economic evaluation and life cycle assessment (LCA) according to a well-defined workflow that guarantees the deermination of sustainable process options, if they exist. . The paper will highlight an improved alternative process design compared to a base case (published) design in terms of production cost, waste, energy usage and environmental impacts, criteria that are asociated with sustainable process design. The final process design includes 39 unit operations, has a capacity of 150,000 L/day and produces dry ethanol (approximately 13.0% of cassava rhizome is converted to ethanol)

Mangnimit, Saranya; Malakul, Pomthong

178

Protein Hydrolysates as Hypoallergenic, Flavors and Palatants for Companion Animals  

Science.gov (United States)

Early civilizations have relied upon their good sense and experience to develop and improve their food quality. The discovery of soy sauce centuries ago can now be considered one of the earliest protein hydrolysates made by man to improve palatability of foods. Now, it is well known that such savory systems are not just sources for enjoyment but complex semiotic systems that direct the humans to satisfy the body's protein need for their sustenance. Recent developments have resulted in a wide range of cost effective savory flavorings, the best known of which are autolyzed yeast extracts and hydrolyzed vegetable proteins. New technologies have helped researchers to improve the savory characteristics of yeast extracts through the application of Maillard reaction and by generating specific flavor enhancers through the use of enzymes. An interesting parallel exists in the pet food industry, where a similar approach is taken in using animal protein hydrolysates to create palatability enhancers via Maillard reaction scheme. Protein hydrolysates are also utilized extensively as a source of nutrition to the elderly, young children and immuno-compromised patient population. These hydrolysates have an added advantage in having peptides small enough to avoid any chance of an allergenic reaction which sometimes occur with the consumption of larger sized peptides or proteins. Accordingly, protein hydrolysates are required to have an average molecular weight distribution in the range 800-1,500 Da to make them non-allergenic. The technical challenge for scientists involved in food and feed manufacture is to use an appropriate combination of enzymes within the existing economic constraints and other physical factors/limitations, such as heat, pH, and time, to create highly palatable, yet still nutritious and hypoallergenic food formulations.

Nagodawithana, Tilak W.; Nelles, Lynn; Trivedi, Nayan B.

179

Enzyme Hydrolysates from Stichopus horrens as a New Source for Angiotensin-Converting Enzyme Inhibitory Peptides.  

Science.gov (United States)

Stichopus horrens flesh was explored as a potential source for generating peptides with angiotensin-converting enzyme (ACE) inhibitory capacity using 6 proteases, namely alcalase, flavourzyme, trypsin, papain, bromelain, and protamex. Degree of hydrolysis (DH) and peptide profiling (SDS-PAGE) of Stichopus horrens hydrolysates (SHHs) was also assessed. Alcalase hydrolysate showed the highest DH value (39.8%) followed by flavourzyme hydrolysate (32.7%). Overall, alcalase hydrolysate exhibited the highest ACE inhibitory activity (IC(50) value of 0.41?mg/mL) followed by flavourzyme hydrolysate (IC(50) value of 2.24?mg/mL), trypsin hydrolysate (IC(50) value of 2.28?mg/mL), papain hydrolysate (IC(50) value of 2.48?mg/mL), bromelain hydrolysate (IC(50) value of 4.21?mg/mL), and protamex hydrolysate (IC(50) value of 6.38?mg/mL). The SDS-PAGE results showed that alcalase hydrolysate represented a unique pattern compared to others, which yielded potent ACE inhibitory peptides with molecular weight distribution lower than 20?kDa. The evaluation of the relationship between DH and IC(50) values of alcalase and flavourzyme hydrolysates revealed that the trend between those parameters was related to the type of the protease used. We concluded that the tested SHHs would be used as a potential source of functional ACE inhibitory peptides for physiological benefits. PMID:22927875

Forghani, Bita; Ebrahimpour, Afshin; Bakar, Jamilah; Abdul Hamid, Azizah; Hassan, Zaiton; Saari, Nazamid

2012-01-01

180

Supercritical CO2 pretreatment of lignocellulose enhances enzymatic cellulose hydrolysis.  

Science.gov (United States)

The supercritical carbon dioxide (SC-CO2) pretreatment of lignocellulose for enzymatic hydrolysis of cellulose was investigated. Aspen (hardwood) and southern yellow pine (softwood) with moisture contents in the range of 0-73% (w/w) were pretreated with SC-CO2 at 3100 and 4000 psi and at 112-165 degrees C for 10-60 min. Each pretreated lignocellulose was hydrolyzed with commercial cellulase to assess its enzymatic digestibility. Untreated aspen and southern yellow pine (SYP) gave final reducing sugar yields of 14.5 +/- 2.3 and 12.8 +/- 2.7% of theoretical maximum, respectively. When no moisture was present in lignocellulose to be pretreated, the final reducing sugar yield from hydrolysis of SC-CO2-pretreated lignocellulose was similar to that of untreated aspen. When the moisture content of lignocellulose was increased, particularly in aspen, significantly increased final sugar yields were obtained from enzymatic hydrolysis of SC-CO2-pretreated lignocellulose. When the moisture content of lignocellulose was 73% (w/w) before pretreatment, the sugar yields from the enzymatic hydrolysis of aspen and southern yellow pine pretreated with SC-CO2 at 3100 psi and 165 degrees C for 30 min were 84.7 +/- 2.6 and 27.3 +/- 3.8% of theoretical maximum, respectively. The SC-CO2 pretreatments of both aspen and SYP with moisture contents of 40, 57, and 73% (w/w) showed significantly higher final sugar yields compared to the thermal pretreatments without SC-CO2. PMID:11272020

Kim, K H; Hong, J

2001-04-01

181

Antioxidant and cryoprotective effects of Amur sturgeon skin gelatin hydrolysate in unwashed fish mince.  

Science.gov (United States)

Antioxidant and cryoprotective effects of Amur sturgeon skin gelatin hydrolysates prepared using different commercial proteases in unwashed fish mince were investigated. Gelatin hydrolysates prepared using either Alcalase or Flavourzyme, were effective in preventing lipid oxidation as evidenced by the lower thiobarbituric acid-reactive substances formation. Gelatin hydrolysates were able to retard protein oxidation as indicated by the retarded protein carbonyl formation and lower loss in sulfhydryl content. In the presence of gelatin hydrolysates, unwashed mince had higher transition temperature of myosin and higher enthalpy of myosin and actin as determined by differential scanning calorimetry. Based on low field proton nuclear magnetic resonance analysis, gelatin hydrolysates prevented the displacement of water molecules between the different compartments, thus stabilizing the water associated with myofibrils in unwashed mince induced by repeated freeze-thawing. Oligopeptides in gelatin hydrolysates more likely contributed to the cryoprotective effect. Thus, gelatin hydrolysate could act as both antioxidant and cryoprotectant in unwashed fish mince. PMID:25794753

Nikoo, Mehdi; Benjakul, Soottawat; Xu, Xueming

2015-08-15

182

Identification of candidate genes for yeast engineering to improve bioethanol production in very high gravity and lignocellulosic biomass industrial fermentations  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background The optimization of industrial bioethanol production will depend on the rational design and manipulation of industrial strains to improve their robustness against the many stress factors affecting their performance during very high gravity (VHG or lignocellulosic fermentations. In this study, a set of Saccharomyces cerevisiae genes found, through genome-wide screenings, to confer resistance to the simultaneous presence of different relevant stresses were identified as required for maximal fermentation performance under industrial conditions. Results Chemogenomics data were used to identify eight genes whose expression confers simultaneous resistance to high concentrations of glucose, acetic acid and ethanol, chemical stresses relevant for VHG fermentations; and eleven genes conferring simultaneous resistance to stresses relevant during lignocellulosic fermentations. These eleven genes were identified based on two different sets: one with five genes granting simultaneous resistance to ethanol, acetic acid and furfural, and the other with six genes providing simultaneous resistance to ethanol, acetic acid and vanillin. The expression of Bud31 and Hpr1 was found to lead to the increase of both ethanol yield and fermentation rate, while Pho85, Vrp1 and Ygl024w expression is required for maximal ethanol production in VHG fermentations. Five genes, Erg2, Prs3, Rav1, Rpb4 and Vma8, were found to contribute to the maintenance of cell viability in wheat straw hydrolysate and/or the maximal fermentation rate of this substrate. Conclusions The identified genes stand as preferential targets for genetic engineering manipulation in order to generate more robust industrial strains, able to cope with the most significant fermentation stresses and, thus, to increase ethanol production rate and final ethanol titers.

Pereira Francisco B

2011-12-01

183

Spent fuel storage pool  

International Nuclear Information System (INIS)

Purpose: To increase the capacities of spent fuel pools in the reactor building by dividing a pair, left and right, of pools communicating with the reactor well pool into two, upper and lower, stages and storing spent fuels in the lower stage. Constitution: At the lower part of a pool communicating with the reactor well pool through pool gates and shield blocks there are provided storage racks thereby to use the pool as an auxiliary machine tentatively set pool concurrently used as a spent fuel storage pool. Furthermore, a pair of spent fuel storage pools are provided at the left and right hand sides of the well pool thereby to double the storage capacity. (Sekiya, K.)

184

Hyperthermophilic endoglucanase for in planta lignocellulose conversion  

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Full Text Available Abstract Background The enzymatic conversion of lignocellulosic plant biomass into fermentable sugars is a crucial step in the sustainable and environmentally friendly production of biofuels. However, a major drawback of enzymes from mesophilic sources is their suboptimal activity under established pretreatment conditions, e.g. high temperatures, extreme pH values and high salt concentrations. Enzymes from extremophiles are better adapted to these conditions and could be produced by heterologous expression in microbes, or even directly in the plant biomass. Results Here we show that a cellulase gene (sso1354 isolated from the hyperthermophilic archaeon Sulfolobus solfataricus can be expressed in plants, and that the recombinant enzyme is biologically active and exhibits the same properties as the wild type form. Since the enzyme is inactive under normal plant growth conditions, this potentially allows its expression in plants without negative effects on growth and development, and subsequent heat-inducible activation. Furthermore we demonstrate that the recombinant enzyme acts in high concentrations of ionic liquids and can therefore degrade ?-cellulose or even complex cell wall preparations under those pretreatment conditions. Conclusion The hyperthermophilic endoglucanase SSO1354 with its unique features is an excellent tool for advanced biomass conversion. Here we demonstrate its expression in planta and the possibility for post harvest activation. Moreover the enzyme is suitable for combined pretreatment and hydrolysis applications.

Klose Holger

2012-08-01

185

Improved lignocellulose conversion to biofuels with thermophilic bacteria and thermostable enzymes  

Science.gov (United States)

Second generation feedstock, especially nonfood lignocellulosic biomass, has been seen as a potential source for biofuel production. Cost intensive pretreatment operations, including physical, chemical, biological, and slow enzymatic hydrolysis, make the overall process of lignocellulosic conversio...

186

Thermoset-cross-linked lignocellulose: a moldable plant biomass.  

Science.gov (United States)

The present work demonstrates a high biomass content (i.e., up to 90% by weight) and moldable material by controlled covalent cross-linking of lignocellulosic particles by a thermoset through epoxide-hydroxyl reactions. As an example for lignocellulosic biomass, Eastern redcedar was employed. Using scanning fluorescence microscopy and vibrational spectroscopy, macroscopic to molecular scale interactions of the thermoset with the lignocellulose have been revealed. Impregnation of the polymer resin into the biomass cellular network by capillary action as well as applied pressure results in a self-organizing structure in the form of thermoset microrods in a matrix of lignocellulose. We also infer permeation of the thermoset into the cell walls from the reaction of epoxides with the hydroxyls of the lignin. Compression tests reveal, at 30% thermoset content, thermoset-cross-linked lignocellulose has superior mechanical properties over a commercial wood plastic composite while comparable stiffness and strength to bulk epoxy and wood, respectively. The failure mechanism is understood to be crack propagation along the particle-thermoset interface and/or interparticle thermoset network. PMID:25734539

Karumuri, Sriharsha; Hiziroglu, Salim; Kalkan, A Kaan

2015-04-01

187

Evaluation of the biomass potential for the production of lignocellulosic bioethanol from various agricultural residues in Austria and Worldwide  

Science.gov (United States)

Due to the fact that the resources of fossil fuels are steadily decreasing, researchers have been trying to find alternatives over the past few years. As bioethanol of the first generation is based on potential food, its production has become an increasingly controversial topic. Therefore the focus of research currently is on the production of bioethanol of the second generation, which is made from cellulosic and lignocellulosic materials. However, for the production of bioethanol of the second generation the fibres have to be pre-treated. In this work the mass balances of various agricultural residues available in Austria were generated and examined in lab scale experiments for their bioethanol potential. The residues were pretreatment by means of state of the art technology (steam explosion), enzymatically hydrolysed and fermented with yeast to produce ethanol. Special attention was paid the mass balance of the overall process. Due to the pretreatment the proportion of cellulose increases with the duration of the pre-treatment, whereby the amount of hemicellulose decreases greatly. However, the total losses were increasing with the duration of the pre-treatment, and the losses largely consist of hemicellulose. The ethanol yield varied depending on the cellulose content of the substrates. So rye straw 200 °C 20 min reaches an ethanol yield of 169 kg/t, by far the largest yield. As result on the basis of the annual straw yield in Austria, approximately 210 000 t of bioethanol (266 million litres) could be produced from the straw of wheat (Triticum vulgare), rye (Secale cereale), oat (Avena sativa) and corn (Zea mays) as well as elephant grass (Miscanthus sinensis) using appropriate pre-treatment. So the greenhouse gas emissions produced by burning fossil fuels could be reduced significantly. About 1.8 million tons of motor gasoline are consumed in Austria every year. The needed quantity for a transition to E10 biofuels could thus be easily provided by bioethanol from straw. We also evaluated the production of world's most important grains (wheat, corn, rice, sugar cain) and we calculated the worldwide production of the relevant lignocellulosic residues. On the basis of our labs scale experiments on bioethanol production, the possible lignocellulosic bioethanol production word wide was determined.

Kahr, Heike; Steindl, Daniel; Wimberger, Julia; Schürz, Daniel; Jäger, Alexander

2013-04-01

188

PRETREATMENT TECHNOLOGIES IN BIOETHANOL PRODUCTION FROM LIGNOCELLULOSIC BIOMASS  

Directory of Open Access Journals (Sweden)

Full Text Available Bioethanol is today most commonly produced from corn grain and sugar cane. It is expected that there will be limits to the supply of these raw materials in the near future. Therefore, lignocellulosic biomass, namely agricultural and forest waste, is seen as an attractive feedstock for future supplies of ethanol.Lignocellulosic biomass consists of lignin, hemicellulose and cellulose. Indeed, complexicity of the lignocellulosic biomass structure causes a pretreatment to be applied prior to cellulose and hemicellulose hydrolysis into fermentable sugars. Pretreatment technologies can be physical (mechanical comminution, pyrolysis, physico-chemical (steam explosion, ammonia fiber explosion, CO2 explosion, chemical(ozonolysis, acid hydrolysis, alkaline hydrolysis, oxidative delignification, organosolvent process and biological ones.

Vanja Januši?

2008-06-01

189

Altered lignin biosynthesis using biotechnology to improve lignocellulosic biofuel feedstocks.  

Science.gov (United States)

Lignocellulosic feedstocks can be converted to biofuels, which can conceivably replace a large fraction of fossil fuels currently used for transformation. However, lignin, a prominent constituent of secondary cell walls, is an impediment to the conversion of cell walls to fuel: the recalcitrance problem. Biomass pretreatment for removing lignin is the most expensive step in the production of lignocellulosic biofuels. Even though we have learned a great deal about the biosynthesis of lignin, we do not fully understand its role in plant biology, which is needed for the rational design of engineered cell walls for lignocellulosic feedstocks. This review will recapitulate our knowledge of lignin biosynthesis and discuss how lignin has been modified and the consequences for the host plant. PMID:25051990

Poovaiah, Charleson R; Nageswara-Rao, Madhugiri; Soneji, Jaya R; Baxter, Holly L; Stewart, Charles N

2014-12-01

190

Disposal of spent fuel  

International Nuclear Information System (INIS)

Based on preliminary analyses, spent fuel assemblies are an acceptable form for waste disposal. The following studies appear necessary to bring our knowledge of spent fuel as a final disposal form to a level comparable with that of the solidified wastes from reprocessing: 1. A complete systems analysis is needed of spent fuel disposition from reactor discharge to final isolation in a repository. 2. Since it appears desirable to encase the spent fuel assembly in a metal canister, candidate materials for this container need to be studied. 3. It is highly likely that some ''filler'' material will be needed between the fuel elements and the can. 4. Leachability, stability, and waste-rock interaction studies should be carried out on the fuels. The major disadvantages of spent fuel as a disposal form are the lower maximum heat loading, 60 kW/acre versus 150 kW/acre for high-level waste from a reprocessing plant; the greater long-term potential hazard due to the larger quantities of plutonium and uranium introduced into a repository; and the possibility of criticality in case the repository is breached. The major advantages are the lower cost and increased near-term safety resulting from eliminating reprocessing and the treatment and handling of the wastes therefrom

191

Hydrolyses of calcium phosphates-allografts composite in physiological solutions.  

Science.gov (United States)

Hydrolysis of calcium phosphates cement- allografts composite in calf serum and that in saline were examined in comparison with those of the calcium phosphates cement in both the solutions. The calcium phosphates cement consists of alpha-tricalcium phosphate (alpha-TCP), tetracalcium phosphate (TetCP), dicalcium phosphate dihydrate (DCPD), and hydroxyapatite (HAP), which is clinically used as Biopex. In the hydrolyses of Biopex-allografts composite in both the solutions, the calcium phosphates cement was transformed into HAP. On the other hand, in the hydrolyses of Biopex, HAP was formed after 1 day and octacalcium phosphate (OCP) was gradually formed after 7 days. In the presence of allografts, plate-like crystals were deposited and in the absence of allografts, needle-like crystals were deposited in both the solutions. By the addition of allografts, the hydrolysis process of the calcium phosphates cement was significantly changed. PMID:16617417

Nomoto, Takuya; Haraguchi, Keiji; Yamaguchi, Shunro; Sugano, Nobuhiko; Nakayama, Hirokazu; Sekino, Tohru; Niihara, Koichi

2006-04-01

192

Recent advances in production of bioethanol from lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

Ethanol is considered the most potential next generation automotive fuel because it is carbon-neutral and could be produced from renewable resources like lignocellulosic biomass. There are some technological barriers such as pretreatment, saccharification of cellulose and hemicellulose matrix, and simultaneous fermentation of hexose and pentose sugars which needs to be addressed for efficient conversion of lignocellulosic biomass to bioethanol. This paper reviews the various process options and kinetic models adopted towards resolving the technological challenges to develop a low-cost commercial process. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Kumar, S. [Biotechnology Area, Indian Institute of Petroleum, Dehradun (India); Department of Chemical Engineering, Indian Institute of Technology, Roorkee (India); Singh, S.P. [Department of Paper Technology, Indian Institute of Technology, Roorkee, Saharanpur Campus (India); Mishra, I.M. [Department of Chemical Engineering, Indian Institute of Technology, Roorkee (India); Adhikari, D.K.

2009-04-15

193

Integration of Lignocellulosic Biomass into Renewable Energy Generation Concepts  

Directory of Open Access Journals (Sweden)

Full Text Available In all European countries various lignocellulosic biomasses such as agricultural residues (straw, strawcontaining dung or fractions from municipal solid waste are available in large amounts, but currently hardly any of thispotential is being used for energy generation. This paper reviews the different options for including lignocellulosicbiomass into renewable energy generation schemes. Not all wastes are suitable to be treated by principally availabletechniques such as anaerobic digestion, ethanol production or thermal valorisation. The present paper gives an overviewof utilisation options for lignocellulosic biomass to either produce biofuels or to integrate such biomass into anaerobicdigestion. Biorefinery concepts are discussed as well.

KUSCH Sigrid

2009-08-01

194

Concentration of lignocellulosic hydrolyzates by solar membrane distillation.  

Science.gov (United States)

A small solar energy collector was run to heat lignocellulosic hydrolyzates through an exchanger, and the heated hydrolyzate was concentrated by vacuum membrane distillation (VMD). Under optimal conditions of velocity of 1.0m/s and 65°C, glucose rejection was 99.5% and the flux was 8.46Lm(-2)h(-1). Fermentation of the concentrated hydrolyzate produced 2.64 times the amount of ethanol as fermentation using the original hydrolyzate. The results of this work indicated the possibility to decrease the thermal energy consumption of lignocellulosic ethanol through using VMD. PMID:22940345

Zhang, Lin; Wang, Yafei; Cheng, Li-Hua; Xu, Xinhua; Chen, Huanlin

2012-11-01

195

Wheat gluten hydrolysate affects race performance in the triathlon  

OpenAIRE

Wheat gluten hydrolysate (WGH) is a food ingredient, prepared by partial enzymatic digestion of wheat gluten, which has been reported to suppress exercise-induced elevation of serum creatinine kinase (CK) activity. However, its effects on athletic performance have not yet been elucidated. This is the presentation of an experiment performed on five female college triathletes who completed an Olympic distance triathlon with or without ingestion of 21 g of WGH during the cycling leg. The experim...

Koikawa, Natsue; Aoki, Emi; Suzuki, Yoshio; Sakuraba, Keishoku; Nagaoka, Isao; Aoki, Kazuhiro; Shimmura, Yuki; Sawaki, Keisuke

2013-01-01

196

KUR spent fuel handling  

International Nuclear Information System (INIS)

The spent fuel elements of HEU (253 as of July 1997 and 389 as of April 2004) will be sent back to US by March 2006. In July 1997, the contract (No. DE-AC09-97SR18907) was completed between DOE and Kyoto University. One or two casks will be made in 1998 and the shipment will start in 1999. So many paper works and negotiations with the Government of Japan and the local governments have been aggressively executed by committee members of Spent Fuel Countermeasure. One of the highlights is to find a port of shipment. Technical and political problems including public acceptance are to be solved. In this paper, mainly technical matters related to spent fuel handling are described. (author)

197

Spent fuel consolidation system  

International Nuclear Information System (INIS)

The spent fuel consolidation system provides method and apparatus for remotely vertically and horizontally compacting an array of spent fuel rods while the fuel rods remain submerged in a coolant. The invention comprises a row ordering section for rearranging the configuration of the fuel rods, horizontal consolidation section for horizontally compacting several rows of fuel rods, and a vertical consolidation section for vertically compacting several rows of horizontally compacted fuel rods. The system is capable of compacting the fuel rods from a given fuel assembly to about one half of the volume originally occupied by such fuel rods in the fuel assembly thereby providing greater storage capacity for a given volume of spent fuel storage

198

Spent fuel pyroprocessing demonstration  

International Nuclear Information System (INIS)

A major element of the shutdown of the US liquid metal reactor development program is managing the sodium-bonded spent metallic fuel from the Experimental Breeder Reactor-II to meet US environmental laws. Argonne National Laboratory has refurbished and equipped an existing hot cell facility for treating the spent fuel by a high-temperature electrochemical process commonly called pyroprocessing. Four products will be produced for storage and disposal. Two high-level waste forms will be produced and qualified for disposal of the fission and activation products. Uranium and transuranium alloys will be produced for storage pending a decision by the US Department of Energy on the fate of its plutonium and enriched uranium. Together these activities will demonstrate a unique electrochemical treatment technology for spent nuclear fuel. This technology potentially has significant economic and technical advantages over either conventional reprocessing or direct disposal as a high-level waste option

199

Safety evaluation of fish protein hydrolysate supplementation in malnourished children.  

Science.gov (United States)

Amizate® is a proprietary protein hydrolysate preparation derived from Atlantic salmon (Salmo salar) using endogenous hydrolytic enzymes; it contains mostly free amino acids and short peptides, as well as small amounts of micronutrients (i.e., vitamins and minerals). In this study, the safety of supplementation with fish protein hydrolysate (Amizate®) was examined in 438 malnourished children in a randomized, placebo-controlled, double-blind, and parallel study. The children were between the ages of six to eight and met the Gomez classification for mild or moderate malnutrition. They were randomized to receive one of three interventions for four months, including a chocolate drink (control), or Amizate® (3 or 6g/day) in a chocolate drink. Administration of Amizate® was well-tolerated, with no adverse events reported. Growth (i.e., body weight gain, changes in height, and body mass index) was not negatively impacted by administration of Amizate®, and routine biochemical analysis of blood and urine samples did not reveal any abnormalities that were attributable to the intervention. Findings from this study demonstrate that daily consumption of 3 or 6g of fish protein hydrolysate (Amizate®) was safe and suitable for supplementing the diets of malnourished children. PMID:24569051

Nesse, Knut Olav; Nagalakshmi, A P; Marimuthu, P; Singh, Mamta; Bhetariya, Preetida J; Ho, Manki; Simon, Ryan R

2014-06-01

200

Study on Hydrolysis Conditions of Flavourzyme in Soybean Polypeptide Alcalase Hydrolysate and Soybean Polypeptide Refining Process  

OpenAIRE

Soybean protein Alcalase hydrolysate was further hydrolyzed by adopting Flavourzyme as hydrolytic enzyme. The optimal hydrolysis conditions of Flavourzyme was that pH was 7.0 at temperature 50°C and E/S(ratio of enzyme and substrate) was 20LAPU/g. Bitterness value was reduced to 2 after Flavourzyme hydrolysis reaction in optimal hydrolysis conditions. The change of molecular weight distribution range from Alcalase hydrolysate to Flavourzyme hydrolysate was not obvious. DH (Degree of hydrolys...

Yongsheng Ma; Lintong Wang; Xianhui Sun; Jianqiang Zhang; Junfeng Wang; Yue Li

2014-01-01

201

Antioxidant activity of hydrolysates and peptide fractions derived from porcine hemoglobin  

OpenAIRE

Porcine hemoglobin hydrolysate (PHH) was prepared with 6 different proteases (flavourzyme, papain, A.S.1398, alcalase, pepsin and trypsin). There was no correlation between extent of hydrolysis and antioxidant activity (p?>?0.05). The peptic hydrolysate prepared at 60 min possessed the strongest antioxidant potential (67.0?±?1.84%) among different hydrolysates, which was fractionated into 4 major types by ultrafiltration membranes with different molecular weight cut-off (MWCO), PHH-...

Sun, Qian; Shen, Huixing; Luo, Yongkang

2010-01-01

202

Biogeochemical cycling of lignocellulosic carbon in marine and freshwater ecosystems: relative contributions of procaryotes and eucaryotes  

International Nuclear Information System (INIS)

The relative contributions of procaryotes and eucaryotes to the degradation of the lignin and polysaccharide components of lignocellulosic detritus in two marine and two freshwater wetland ecosystems were determined. Two independent methods - physical separation of bacteria from fungi and other eucaryotes by size fractionation, and antibiotic treatments - were used to estimate procaryotic and eucaryotic contributions to the degradation of [14C-lignin]lignocelluloses and [13C-polysaccharide]lignocelluloses in samples of water and decaying plant material from each environment. Both methods yielded similar results; bacteria were the predominant degraders of lignocellulose in each of the aquatic ecosystems. These results indicate a basic difference between the microbial degradation of lignocellulosic material in terrestrial and aquatic environments. Fungi have long been considered the predominant degraders of lignocellulose in terrestrial systems; our results indicate that in aquatic systems bacteria are the predominant degraders of lignocellulose

203

Optimization of the enzyme system for hydrolysis of pretreated lignocellulose substrates; Optimering av enzymsystemet foer hydrolys av foerbehandlade lignocellulosa substrat  

Energy Technology Data Exchange (ETDEWEB)

This project aims to clarify the reasons for the slow and incomplete enzymatic hydrolysis of certain lignocellulose substrates, particularly softwood e.g. spruce. Based on this knowledge we will optimize the enzyme system so that the yield of fermentable sugars is increased as well as the rate of hydrolysis. We will also study methods for recycling of the enzymes in the process by adsorption on fresh substrate. Progress in these areas will lead to improved process economy in an ethanol process. We collaborate with Chemical Engineering on hydrolysis of pretreated lignocellulose substrates and with Analytical Chemistry and Applied Microbiology on analysis of potential inhibitors. Within this main research direction the work at Biochemistry during this project period (since 970701) has been focused on the following areas: (1) Studies of the role of substrate properties in the enzymatic hydrolysis to clarify the reasons for the decrease in the rate of hydrolysis; (2) enzyme adsorption on lignin; (3) studies of recently identified low molecular weight endo glucanases which may be used for more effective penetration of small pores in pretreated substrates (this part is financed by the Nordic Energy Research Program). Central results during the period: In order to study the role of substrate properties for hydrolysis we have initiated investigations on steam pretreated substrates with several techniques. Measurements of pore sizes have been done with probe molecules of known molecular weights. Results show that probe molecules with diameters larger than 50 Aangstroem can more easily penetrate pretreated willow compared with spruce, which can be a part of the explanation for the better hydrolysability of hardwood substrates compared with softwood. We have started studies with electron microscopy of pretreated substrates at different degrees of enzymatic hydrolysis. With scanning electron microscopy (SEM) we can see significant differences in substrate structure in comparisons before and after hydrolysis. For better interpretation of enzyme effects on substrates we have started studies with transmission electron microscopy (TEM) where we aim to study enzyme binding to the cellulose and lignin parts of the substrate. Studies of enzymatic hydrolysis of steam pretreated spruce have been done to clarify the reasons for the drastic reduction on hydrolysis rate in the later stage of hydrolysis. Results show that the hydrolysis rate for the enzymes CBHI and EGI is reduced to 10% of the initial rate already after 60 min. Additions of fresh enzymes to the hydrolysed substrate leads to increased hydrolysis rate. Our conclusion is that the enzymes become unproductively bound to the substrate during the course of hydrolysis which leads to reduction of the effective enzyme concentration. In studies of the synergy between CBHI and EGI we have observed that the synergy between the enzymes is increasing during the hydrolysis, which can be explained by the increased need for the exo-enzyme CBHI to have access to free cellulose chain ends which can be formed by the action of endo glucanase I. This points to the possibility to increase the hydrolysis rate by addition of extra endo glucanase during the later stages of the hydrolysis. The adsorption of the enzymes on the lignin is of importance since the pretreated substrate is a lignocellulose complex. A strong adsorption to the lignin may reduce the amount of enzymes available for cellulose hydrolysis, and can reduce the possibilities for enzyme recycling. Our studies show that the central enzyme CBHI is strongly adsorbed to alkali extracted lignin and that the binding kinetics are fast.

Tjerneld, Folke [Lund univ., (Sweden). Dept. of Biochemistry

2000-06-01

204

Umwandlung von Lignocellulose-Material in vergärbare Zucker  

OpenAIRE

Die Umwandlung von Lignocellulose-Biomasse zu Biokraftstoffen ist eine vielversprechende Technologie, um diese einzigartige und nachhaltige Ressource zur Bereitstellung von umweltfreundlichen, organischen Brennstoffen und Chemikalien zu nutzen. Die meisten Projektionen zur globalen Energienutzung gehen davon aus, dass Biomasse eine wichtige Komponente der primären Energieversorgung in Zukunft sein wird. Hierbei stellt Agrarholz die primäre Quelle von Biomasse. Kurzumtrieb-Weidenholz (Salix ...

Mohammed, Asem Hassan

2012-01-01

205

EXTRACTING LIGNOCELLULOSE AND SYNTHESIZING SILICA NANOPARTICLES FROM RICE HUSKS  

Science.gov (United States)

At the end of this project, we will have the demonstration package including lignocellulose fibers and silica nanoparticles (with microscope images), and a chart illustrating the optimized process. We will also submit a conference abstract and a journal manuscript for national...

206

Lignin Production by Organosolv Fractionation of Lignocellulosic Biomass  

Energy Technology Data Exchange (ETDEWEB)

The contents of this presentation comprise an introduction of Lignin and lignocellulosic biomass, and Biomass pre-treatment and fractionation; outline of Organosolv fractionation (Experimental set-up, Process conditions, and Catalysts); the Production and Characterisation of Lignin, and finally the Conclusions.

Huijgen, W.J.J.; De Wild, P.J.; Reith, J.H. [ECN Biomass, Coal and Environment, Petten (Netherlands)

2010-09-15

207

Lignocellulose Biomass: Constitutive Polymers. Biological Processes of Lignin Degradation  

International Nuclear Information System (INIS)

The structure of the lignocellulosic materials and the chemical composition of their main constitutive polymers, cellulose, hemicelluloses and lignin are described. The most promising transformation processes according to the type of biomass considered: hardwood, softwood an herbaceous and the perspectives of biotechnological processes for bio pulping, bio bleaching and effluents decolorisation in the paper pulp industry are also discussed. (Author) 7 refs

208

Production, characterization and application of activated carbon from brewer’s spent grain lignin  

OpenAIRE

Different types of activated carbon were prepared by chemical activation of brewer’s spent grain (BSG) lignin using H3PO4 at various acid/lignin ratios (1, 2, or 3 g/g) and carbonization temperatures (300, 450, or 600 °C), according to a 22 full-factorial design. The resulting materials were characterized with regard to their surface area, pore volume, and pore size distribution, and used for detoxification of BSG hemicellulosic hydrolysate (a mixture of sugars, phenolic compounds, metalli...

Mussatto, Solange I.; Fernandes, Marcela; Rocha, George J. M.; O?rfa?o, Jose? J. M.; Teixeira, J. A.; Roberto, Ine?s Conceic?a?o

2010-01-01

209

Radical scavenging and reducing ability of tilapia (Oreochromis niloticus) protein hydrolysates.  

Science.gov (United States)

Enzymatically hydrolyzed fish protein hydrolysates could be used as a source of antioxidative nutraceuticals. In our current work, we have investigated alkali-solubilized tilapia ( Oreochromis niloticus) protein hydrolysates for their ability to scavenge reactive oxygen species (ROS) and for their reducing power. Tilapia protein isolate was prepared by an alkaline solubilization technique and used as a substrate for enzyme hydrolysis. Cryotin, protease A 'Amano' 2, protease N 'Amano', Neutrase and Flavourzyme, were used separately to determine their effectiveness in hydrolyzing tilapia protein isolate. ROS scavenging ability was quantified using an isoluminol enhanced chemiluminescent assay in the presence of a) hydrogen peroxide or b) mononuclear cells isolated from human blood. Ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) of the hydrolysates using 2, 2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) or 2,2'-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS), were also investigated. Results showed that, in general, the TEAC, FRAP values and ROS scavenging ability of the hydrolysates increased with an increase in the degree of hydrolysis. Among the different hydrolysates, those prepared using Cryotin were most effective and Amano A2 hydrolysates were least effective in scavenging ABTS*(+) and ROS generated by hydrogen peroxide. However, FRAP assay showed that hydrolysates prepared using Flavourzyme were most effective, and Amano N and Neutrase hydrolysates were least effective in reducing ferric ions. No significant difference was observed among the hydrolysates produced with different enzymes in their ability to scavenge ROS generated by phorbol myristate acetate stimulated mononuclear cells. These results shed light on the in vitro ROS scavenging ability of alkali solubilized tilapia protein hydrolysates, as well as potential nutraceutical use of these hydrolysates. PMID:18828605

Raghavan, Sivakumar; Kristinsson, Hordur G; Leeuwenburgh, Christiaan

2008-11-12

210

Spent fuel storage alternatives  

International Nuclear Information System (INIS)

This paper compares a small onsite wet storage pool to a dry cask storage facility in order to determine what type of spent fuel storage alternatives would best serve the utilities in consideration of the Nuclear Waste Policy Act of 1982. The Act allows the DOE to provide a total of 1900 metric tons (MT) of additional spent fuel storage capacity to utilities that cannot reasonably provide such capacity for themselves. Topics considered include the implementation of the Act (DOE away-from reactor storage), the Act's impact on storage needs, and an economic evaluation. The Waste Act mandates schedules for the determination of several sites, the licensing and construction of a high-level waste repository, and the study of a monitored retrievable storage facility. It is determined that a small wet pool storage facility offers a conservative and cost-effective approach for many stations, in comparison to dry cask storage

211

Debittering of Protein Hydrolysates by Lactobacillus LBL-4 Aminopeptidase  

OpenAIRE

Yoghurt strain Lactobacillus LBL-4 cultivated for 8–10?h at pH ~6.0 was investigated as a considerable food-grade source of intracellular aminopeptidase. Cell-free extract manifesting >200?AP U/l was obtained from cells harvested from 1?L culture media. Subtilisin-induced hydrolysates of casein, soybean isolate, and Scenedesmus cell protein with degree of hydrolysis 20–22% incubated at 45°C for 10?h by 10 AP?U/g peptides caused an enlarging of DH up to 40–42%, 46–48%, and 3...

Tchorbanov, Bozhidar; Marinova, Margarita; Grozeva, Lydia

2011-01-01

212

Encapsulating spent nuclear fuel  

International Nuclear Information System (INIS)

A system is described for encapsulating spent nuclear fuel discharged from nuclear reactors in the form of rods or multi-rod assemblies. The rods are completely and contiguously enclosed in concrete in which metallic fibres are incorporated to increase thermal conductivity and polymers to decrease fluid permeability. This technique provides the advantage of acceptable long-term stability for storage over the conventional underwater storage method. Examples are given of suitable concrete compositions. (UK)

213

Scintillator spent fuel monitor  

International Nuclear Information System (INIS)

A monitor for rapidly measuring the gross gamma-ray flux immediately above spent fuel assemblies in underwater storage racks has been developed. It consists of a plastic scintillator, photomultiplier, collimator, and a small battery-powered electronics package. The crosstalk from an isolated fuel assembly to an adjacent void is only about 2%. The mean difference between the measured gamma-ray flux and the flux estimated from the declared burnup and cooling time with a simple formula is 22%

214

Spent fuel dissolution mechanisms  

International Nuclear Information System (INIS)

This study is a literature survey on the dissolution mechanisms of spent fuel under disposal conditions. First, the effects of radiolysis products on the oxidative dissolution mechanisms and rates of UO2 are discussed. These effects have mainly been investigated by using electrochemical methods. Then the release mechanisms of soluble radionuclides and the dissolution of the UO2 matrix including the actinides, are treated. Experimental methods have been developed for measuring the grain-boundary inventories of radionuclides. The behaviour of cesium, strontium and technetium in leaching tests shows different trends. Comparison of spent fuel leaching data strongly suggests that the release of 90Sr into the leachant can be used as a measure of the oxidation/dissolution of the fuel matrix. Approaches to the modelling UO2, dissolution are briefly discussed in the next chapter. Lastly, the use of natural material, uraninite, in the evaluation of the long-term performance of spent fuel is discussed. (orig.). (81 ref., 37 figs., 8 tabs.)

215

FRACTIONATION OF LIGNOCELLULOSIC BIOMASS FOR FUEL-GRADE ETHANOL PRODUCTION  

Energy Technology Data Exchange (ETDEWEB)

PureVision Technology, Inc. (PureVision) of Fort Lupton, Colorado is developing a process for the conversion of lignocellulosic biomass into fuel-grade ethanol and specialty chemicals in order to enhance national energy security, rural economies, and environmental quality. Lignocellulosic-containing plants are those types of biomass that include wood, agricultural residues, and paper wastes. Lignocellulose is composed of the biopolymers cellulose, hemicellulose, and lignin. Cellulose, a polymer of glucose, is the component in lignocellulose that has potential for the production of fuel-grade ethanol by direct fermentation of the glucose. However, enzymatic hydrolysis of lignocellulose and raw cellulose into glucose is hindered by the presence of lignin. The cellulase enzyme, which hydrolyzes cellulose to glucose, becomes irreversibly bound to lignin. This requires using the enzyme in reagent quantities rather than in catalytic concentration. The extensive use of this enzyme is expensive and adversely affects the economics of ethanol production. PureVision has approached this problem by developing a biomass fractionator to pretreat the lignocellulose to yield a highly pure cellulose fraction. The biomass fractionator is based on sequentially treating the biomass with hot water, hot alkaline solutions, and polishing the cellulose fraction with a wet alkaline oxidation step. In September 2001 PureVision and Western Research Institute (WRI) initiated a jointly sponsored research project with the U.S. Department of Energy (DOE) to evaluate their pretreatment technology, develop an understanding of the chemistry, and provide the data required to design and fabricate a one- to two-ton/day pilot-scale unit. The efforts during the first year of this program completed the design, fabrication, and shakedown of a bench-scale reactor system and evaluated the fractionation of corn stover. The results from the evaluation of corn stover have shown that water hydrolysis prior to alkaline hydrolysis may be beneficial in removing hemicellulose and lignin from the feedstock. In addition, alkaline hydrolysis has been shown to remove a significant portion of the hemicellulose and lignin. The resulting cellulose can be exposed to a finishing step with wet alkaline oxidation to remove the remaining lignin. The final product is a highly pure cellulose fraction containing less than 1% of the native lignin with an overall yield in excess of 85% of the native cellulose. This report summarizes the results from the first year's effort to move the technology to commercialization.

F.D. Guffey; R.C. Wingerson

2002-10-01

216

Enzymatic hydrolysis of recovered protein from frozen small croaker and functional properties of its hydrolysates.  

Science.gov (United States)

Fish protein isolate were recovered from frozen small croaker using pH shift. The partial enzymatic hydrolysates were fractionated as soluble and insoluble parts. They were dried using the drum dryer and their functional properties were examined. The total nitrogen content of the enzymatic hydrolysates ranged from 12.9% to 13.7%. The degree of hydrolysis of precipitates was 18.2% and 12.2% for croaker hydrolysates treated with Protamex 1.5 MG (Bacilllus protease complex) and Flavourzyme 500 MG (endoproteases and exoproteases, Aspergillus oryzae), respectively. The TCA supernatant, after centrifugation of hydrolysates, contained numerous peptides ranging from 100 to 4000 daltons. The solubility of the supernatants was higher than that of the precipitates at 0% to 3% NaCl and pH 2 to 10. The precipitate of Flavourzyme- and Protamex-treated hydrolysates showed a high emulsion activity index value compared to egg white and bovine plasma protein. In addition, the highest emulsion stability was observed for Protamex-treated precipitate hydrolysates. Emulsion stability of Protamex-treated precipitate hydrolysates was comparable to those of protein additives (egg white, bovine plasma protein, and soy protein concentrate). Water and fat binding capacity of precipitates were higher than those of supernatant. The results indicate that precipitate hydrolysate from undersized croaker can be used in processed muscle foods as a functional and nutritional ingredient. PMID:19200081

Choi, Yeung Joon; Hur, Sungik; Choi, Byeong-Dae; Konno, Kunihiko; Park, Jae W

2009-01-01

217

Production of defatted palm kernel cake protein hydrolysate as a valuable source of natural antioxidants.  

Science.gov (United States)

The aim of this study was to produce a valuable protein hydrolysate from palm kernel cake (PKC) for the development of natural antioxidants. Extracted PKC protein was hydrolyzed using different proteases (alcalase, chymotrypsin, papain, pepsin, trypsin, flavourzyme, and bromelain). Subsequently, antioxidant activity and degree of hydrolysis (DH) of each hydrolysate were evaluated using DPPH• radical scavenging activity and O-phthaldialdehyde spectrophotometric assay, respectively. The results revealed a strong correlation between DH and radical scavenging activity of the hydrolysates, where among these, protein hydrolysates produced by papain after 38 h hydrolysis exhibited the highest DH (91 ± 0.1%) and DPPH• radical scavenging activity (73.5 ± 0.25%) compared to the other hydrolysates. In addition, fractionation of the most effective (potent) hydrolysate by reverse phase high performance liquid chromatography indicated a direct association between hydrophobicity and radical scavenging activity of the hydrolysates. Isoelectric focusing tests also revealed that protein hydrolysates with basic and neutral isoelectric point (pI) have the highest radical scavenging activity, although few fractions in the acidic range also exhibited good antioxidant potential. PMID:22942692

Zarei, Mohammad; Ebrahimpour, Afshin; Abdul-Hamid, Azizah; Anwar, Farooq; Saari, Nazamid

2012-01-01

218

Dipeptidyl peptidase IV inhibitory and antioxidative properties of milk protein-derived dipeptides and hydrolysates.  

Science.gov (United States)

Selected synthetic dipeptides and milk protein hydrolysates were evaluated for their dipeptidyl peptidase IV (DPP-IV) inhibitory properties, and their superoxide (SO) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities. DPP-IV inhibition was seen with eight out of the twelve dipeptides and 5 of the twelve hydrolysates studied. Trp-Val inhibited DPP-IV, however, inhibition was not observed with the reverse peptide Val-Trp. The most potent hydrolysate inhibitors were generated from casein (CasH2) and lactoferrin (LFH1). Two Trp containing dipeptides, Trp-Val and Val-Trp, and three lactoferrin hydrolysates scavenged DPPH. The dipeptides had higher SO EC(50) values compared to the milk protein hydrolysates (arising from three lactoferrin and one whey protein hydrolysates). Higher molecular mass fractions of the milk protein hydrolysates were associated with the SO scavenging activity. Trp-Val and one lactoferrin hydrolysate (LFH1) were multifunctional displaying both DPP-IV inhibitory and antioxidant (SO and DPPH scavenging) activities. These compounds may have potential as dietary ingredients in the management of type 2 diabetes by virtue of their ability to scavenge reactive oxygen species and to extend the half-life of incretin molecules. PMID:23219487

Nongonierma, Alice B; FitzGerald, Richard J

2013-01-01

219

Total reuse of brewer’s spent grain in chemical and biotechnological processes for the production of added-value compounds  

OpenAIRE

Brewer’s spent grain was fractionated by means of three different procedures: dilute acid hydrolysis, for the hemicellulose recovery; alkaline hydrolysis, for the lignin solubilization, and enzymatic hydrolysis, for the cellulose conversion into glucose. The best hydrolysis conditions were optimized to each case. The cellulosic and hemicellulosic hydrolysates produced under these conditions were used as fermentation medium for the production of lactic acid and xylitol, respectively. The eff...

Mussatto, Solange I.; Dragone, Giuliano; Teixeira, J. A.; Roberto, Ine?s Conceic?a?o

2008-01-01

220

The quality of silage of corn grain and spent P. ostreatus mushroom substrate  

Directory of Open Access Journals (Sweden)

Full Text Available The chemical composition, fermentation quality, mycological and mycotoxicological analyses of silage mixture, made of ground corn grain and spent P. ostreatus mushroom substrate, were investigated in this paper. Dry matter content in high moisture ground corn, at the time of ensiling was 70%, and in the spent substrate (on the Salt Cedar wood shaving basis was 52.7%. Corn grain to spent substrate ratio in trials was: 100:0% (I, 90:10% (II, 80:20% (III and 70:30% (IV respectively. Content of the lignocellulose fractions in silage was slightly increased, and protein content was slightly decreased with the increase of spent substrate content. Contents of the VFA (volatile fatty acids in silage, pH value, and NH3-N content were for the silage of very good quality. In the spent substrate 9 mold species were found, from which the most frequent were genus Penicillium, Paecilomyces variotii, and Trichoderma harzianum. In ground corn grain silage (I presence of the yeasts was dominant (90.000/g. In combined trials (II-IV only Penicillium (P. brevicompactum and P. echinulatum mold species were found. Presence of molds and yeasts in investigated trials was within tolerated values for ensiled feedstuffs. Mycotoxin presence in silage was not determined.

Adamovi? Milan J.

2007-01-01

221

Positron lifetime reveals the nano level packing in complex polysaccharide-rich hydrolysate matrixes.  

Science.gov (United States)

Positron annihilation lifetime spectroscopy (PALS) was used to quantify the free volume and molecular packing in hydrolysate and hemicellulose-based barriers films, derived from process streams during wood processing operations. These hydrolysate films, comprising a fair share of lignin coexisting with poly- and oligo-saccharides, have very low but variable oxygen permeability but differ among themselves with respect to barrier performance as well as molecular weight, degree of branching, and monosaccharide residue main chain composition. From PALS measurements on hydrolysates, the free volume hole radius (r(h)), radius distributions (n(r(h))), volume-weighted hole sizes ((v)), and hole volume distributions (g(v(h))) were calculated showing that the hydrolysate matrixes are very densely packed with small holes. The results show a clear relationship between hydrolysate molecular architecture and composition, the nanolevel molecular packing, and the ability of suppressing the diffusion of oxygen through the film. PMID:22455471

Edlund, Ulrica; Yu, Yang; Ryberg, Yingzhi Zhu; Krause-Rehberg, Reinhard; Albertsson, Ann-Christine

2012-04-17

222

Antioxidant activity of bovine casein hydrolysates produced by Ficus carica L.-derived proteinase.  

Science.gov (United States)

A Ficus carica L. latex proteinase preparation was investigated for its ability to produce antioxidant hydrolysates/peptides from bovine casein (CN). The Oxygen Radical Absorbance Capacity (ORAC) values for NaCN and ?-CN hydrolysates ranged from 0.06 to 0.18, and from 0.51 to 1.19?mol Trolox equivalents/mg freeze-dried sample, respectively. Gel permeation HPLC showed that the ?-CN hydrolysate with a degree of hydrolysis of 21% had 65% of peptide material with a molecular mass <500Da. The RP-UPLC profiles also indicated that ?-CN was substantially hydrolysed during the early stages of hydrolysis. Analysis of the 4h ?-CN hydrolysate by LC-ESI-MS/MS allowed identification of 8 peptide sequences with potential antioxidant properties. PMID:24629973

Di Pierro, Giovanna; O'Keeffe, Martina B; Poyarkov, Alexey; Lomolino, Giovanna; FitzGerald, Richard J

2014-08-01

223

In vitro binding capacity of bile acids by defatted corn protein hydrolysate.  

Science.gov (United States)

Defatted corn protein was digested using five different proteases, Alcalase, Trypsin, Neutrase, Protamex and Flavourzyme, in order to produce bile acid binding peptides. Bile acid binding capacity was analyzed in vitro using peptides from different proteases of defatted corn hydrolysate. Some crystalline bile acids like sodium glycocholate, sodium cholate and sodium deoxycholate were individually tested using HPLC to see which enzymes can release more peptides with high bile acid binding capacity. Peptides from Flavourzyme defatted corn hydrolysate exhibited significantly (p Flavourzyme hydrolysate was almost preserved after gastrointestinal proteases digestion. The molecular weight of Flavourzyme hydrolysate was determined and most of the peptides were found between 500-180 Da. The results showed that Flavourzyme hydrolysate may be used as a potential cholesterol-reducing agent. PMID:21541043

Kongo-Dia-Moukala, Jauricque Ursulla; Zhang, Hui; Irakoze, Pierre Claver

2011-01-01

224

Advancing lignocellulose bioconversion through direct assessment of enzyme action on insoluble substrates  

DEFF Research Database (Denmark)

Microbial utilization of lignocellulose from plant cell walls is integral to carbon cycling on Earth. Correspondingly, secreted enzymes that initiate lignocellulose depolymerization serve a crucial step in the bioconversion of lignocellulosic biomass to fuels and chemicals. Genome and metagenome sequencing efforts that span the past decade reveal the diversity of enzymes that have evolved to transform lignocellulose from wood, herbaceous plants and grasses. Nevertheless, there are relatively few examples where ‘omic’ technologies have identified novel enzyme activities or combinations thereof that dramatically improve the economics of lignocellulose bioprocessing and utilization. A likely factor contributing to the discrepancy between sequence-based enzyme discovery and enzyme application is the common practice to screen enzyme candidates based on activity measurements using soluble model compounds. In this context, the development and application of imaging, physicochemical, and spectromicroscopic techniquesthat allow direct assessment of enzyme action on relevant lignocellulosic substrates is reviewed.

Goacher, Robyn E.; Selig, Michael J.

2014-01-01

225

Thermophysical Properties of Lignocellulose: A Cell-scale Study down to 41K  

CERN Document Server

Thermal energy transport is of great importance in lignocellulose pyrolysis for bio-fuels. The thermophysical properties of lignocellulose significantly affect the overall properties of bio-composites and the related thermal transport. In this work, cell-scale lignocellulose (mono-layer plant cells) is prepared to characterize their thermal properties from room temperature down to 41 K. The thermal conductivities of cell-scale lignocellulose along different directions show a little anisotropy due to the cell structure anisotropy. It is found that with temperature going down, the volumetric specific heat of the lignocellulose shows a slower decreasing trend against temperature than that of microcrystalline cellulose, and its value is always higher than that of microcrystalline cellulose. The thermal conductivity of lignocellulose decreases with temperature from 243 K to 317 K due to increasing phonon-phonon scatterings. From 41 K to 243 K, the thermal conductivity rises with temperature and its change mainly d...

Cheng, Zhe; Zhang, Lei; Wang, Xinwei

2014-01-01

226

Enzymatic preparation of immunomodulating hydrolysates from soy proteins.  

Science.gov (United States)

Soy protein hydrolysates with lower molecular weight were enzymatically prepared by several commercially available proteases (Alcalase 2.4L, Flavourzyme, Trypsin, Papain, Protease A and Peptidase R) with protein recovery varied from 42.59% to 79.87%. Relative content of positively charged peptides was determined on SP Sephadex C-25 using gradient sodium chloride solution as eluents. Immunomodulating properties were evaluated by measuring their effect on in vitro proliferation of murine spleen lymphocytes and phagocytic activity of peritoneal macrophages. The results showed that soy protein hydrolysates (SPHs) prepared with Alcalase and insoluble soy protein (InSP), preferable to other enzymes and soy proteins, have the highest immunomodulating activity and the optimum conditions were determined as follows: E/S=2% (Alcalase), 60 degrees C, pH 8.0, InSP concentration 6% and 225min. Positive correlations were obtained between the immunomodulating activity and content of positively charged peptides. The results suggested that lower molecular weight and positively charged peptides released from soy protein were effective in stimulating immunomodulating activity, thus provided insights into the preparation of potent immunomodulating products. PMID:18524579

Kong, Xiangzhen; Guo, Mingming; Hua, Yufei; Cao, Dong; Zhang, Caimeng

2008-12-01

227

Antioxidative, DPP-IV and ACE inhibiting peptides from fish protein hydrolysed with intestinal proteases  

DEFF Research Database (Denmark)

Proteins from fish tissue could be a promising source of peptides with a nutritional and pharmaceutical value, e.g. as treatment of type 2 diabetes with dipeptidyl peptidase IV (DPP-IV) inhibiting peptides, and could be used in health and functional foods and thereby increasing the value of secondary marine products. The approach in this study is to hydrolyse skin and belly flap tissue from Salmon with the use of mammalian digestive proteases from pancreas and intestinal mucosa and test hydrolysates for antioxidative capacity, intestinal DPP-IV and angiotensin converting enzyme (ACE) inhibiting properties. 10kDa dialysis bags containing 10ml water were added to homogenized fish tissues, which were subsequently hydrolysed for 24 hours at 37?C and pH 8 with intestinal mucosa extract and/or pancreatin solution from pig. Dialysis bags were then removed and content were analyzed for free amino groups, antioxidative capacity by ABTS (2,2-azinobis(3-ethylbenzothiazoline-6-sulfonicacid)), DPP-IV and ACE inhibiting activity. Degree of hydrolysis (DH) of hydrolysates was approximately 13% and 10% for belly flap and skin respectively. No clear difference was observed in DH between pancreatin and pancreatin + mucosa hydrolysates. No DH was obtained for tissues hydrolysed with only intestinal mucosa extract. Preliminary results showed antioxidant activity and intestinal DPP-IV and ACE inhibiting activity in 10 kDa fraction from both belly flap and skin hydrolysates but with a higher antioxidative capacity in belly flap hydrolysates. No difference between hydrolysates with pancreatin and pancreatin+mucosa was observed. Hydrolysates will be further fractionated by gelfiltration. Fractions will be analyzed for the three bioactivities and also presented.

Falkenberg, Susan Skanderup; Stagsted, Jan

228

Canonical correlations between chemical and energetic characteristics of lignocellulosic wastes  

Directory of Open Access Journals (Sweden)

Full Text Available Canonical correlation analysis is a statistical multivariate procedure that allows analyzing linear correlation that may exist between two groups or sets of variables (X and Y. This paper aimed to provide canonical correlation analysis between a group comprised of lignin and total extractives contents and higher heating value (HHV with a group of elemental components (carbon, hydrogen, nitrogen and sulfur for lignocellulosic wastes. The following wastes were used: eucalyptus shavings; pine shavings; red cedar shavings; sugar cane bagasse; residual bamboo cellulose pulp; coffee husk and parchment; maize harvesting wastes; and rice husk. Only the first canonical function was significant, but it presented a low canonical R². High carbon, hydrogen and sulfur contents and low nitrogen contents seem to be related to high total extractives contents of the lignocellulosic wastes. The preliminary results found in this paper indicate that the canonical correlations were not efficient to explain the correlations between the chemical elemental components and lignin contents and higher heating values.

Thiago de Paula Protásio

2012-09-01

229

Flow-through biological conversion of lignocellulosic biomass  

Science.gov (United States)

The present invention is directed to a process for biologically converting carbohydrates from lignocellulosic biomass comprising the steps of: suspending lignocellulosic biomass in a flow-through reactor, passing a reaction solution into the reactor, wherein the solution is absorbed into the biomass substrate and at least a portion of the solution migrates through said biomass substrate to a liquid reservoir, recirculating the reaction solution in the liquid reservoir at least once to be absorbed into and migrate through the biomass substrate again. The biological converting of the may involve hydrolyzing cellulose, hemicellulose, or a combination thereof to form oligosaccharides, monomelic sugars, or a combination thereof; fermenting oligosaccharides, monomelic sugars, or a combination thereof to produce ethanol, or a combination thereof. The process can further comprise removing the reaction solution and processing the solution to separate the ethanol produced from non-fermented solids.

Herring, Christopher D.; Liu, Chaogang; Bardsley, John

2014-07-01

230

VALORIZATION AND BIODECOLORIZATION OF DYE ADSORBED ON LIGNOCELLULOSICS USING WHITE ROT FUNGI  

OpenAIRE

Biosorption of dyes by lignocelluloses may be an effective method for removing dyes from textile effluents. However, the resulting dye-adsorbed lignocellulosic materials may constitute another pollution problem. An integrated method can solve this problem. Here, various lignocelluloses were tested for their Astrazon Black and Astrazon Blue dyes removal activities. The dye adsorbed after 30 min contact time was 90% (45 mg/L), 70% (35 mg/L), and 98% (49 mg/L) for wheat bran, pine cone, and cott...

Nesrin Ozmen,; Ozfer Yesilada

2012-01-01

231

The NILE project : advances in the conversion of lignocellulosic materials into ethanol.  

OpenAIRE

NILE ("New Improvements for Lignocellulosic Ethanol") was an integrated European project (2005-2010) devoted to the conversion of ligno-cellulosic raw materials to ethanol. The main objectives were to design novel enzymes suitable for the hydrolysis of cellulose to glucose and new yeast strains able to efficiently converting all the sugars present in lignocellulose into ethanol. The project also included testing these new developments in an integrated pilot plant and evaluating the environmen...

Monot, F.; Margeot, A.; Hahn-ha?gerdal, B.; Lindstedt, J.; Slade, R.

2013-01-01

232

Anaerobic Biodegradation of the Lignin and Polysaccharide Components of Lignocellulose and Synthetic Lignin by Sediment Microflora †  

OpenAIRE

Specifically radiolabeled [14C-lignin]lignocelluloses and [14C-polysaccharide]lignocelluloses were prepared from a variety of marine and freshwater wetland plants including a grass, a sedge, a rush, and a hardwood. These [14C]lignocellulose preparations and synthetic [14C]lignin were incubated anaerobically with anoxic sediments collected from a salt marsh, a freshwater marsh, and a mangrove swamp. During long-term incubations lasting up to 300 days, the lignin and polysaccharide components o...

Benner, Ronald; Maccubbin, A. E.; Hodson, Robert E.

1984-01-01

233

Fermentation to ethanol of pentose-containing spent sulphite liquor.  

Science.gov (United States)

Ethanolic fermentation of spent sulphite liquor with ordinary bakers' yeast is incomplete because this yeast cannot ferment the pentose sugars in the liquor. This results in poor alcohol yields, and a residual effluent problem By using the yeast Candida shehatae (R) for fermentation of the spent sulphite liquor from a large Canadian alcohol-producing sulphite pulp and paper mill, pentoses as well as hexoses were fermented nearly completely, alcohol yields were raised by 33%, and sugar removal increased by 46%. Inhibitors were removed prior to fermentation by steam stripping. Major benefits were obtained by careful recycling of this yeast, which was shown to be tolerant both of high sugar concentrations and high alcohol concentrations. When sugar concentrations over 250 g/L (glucose: xylose 70:30) were fermented, ethanol became an inhibitor when its concentration reached 90 g/L. However, when the ethanol was removed by low-temperature vacuum distillation, fermentation continued and resulted in a yield of 0.50 g ethanol/g sugar consumed. Further improvement was achieved by combining enzyme saccharification of sugar oligomers with fermentation. This yeast is able to ferment both hexoses and pentoses simultaneously, efficiently, and rapidly. Present indications are that it is well suited to industrial operations wherever hexoses and pentoses are both to be fermented to ethanol, for example, in wood hydrolysates. PMID:18576569

Yu, S; Wayman, M; Parekh, S K

1987-06-01

234

Fermentation to ethanol of pentose-containing spent sulphite liquor  

Energy Technology Data Exchange (ETDEWEB)

Ethanolic fermentation of spent sulphite liquor with ordinary bakers' yeast is incomplete because this yeast cannot ferment the pentose sugars in the liquor. This results in poor alcohol yields, and a residual effluent problem. By using the yeast Candida shehatae (R) for fermentation of the spent sulphite liquor from a large Canadian alcohol-producing sulphite pulp and paper mill, pentoses as well as hexoses were fermented nearly completely, alcohol yields were raised by 33%, and sugar removal increased by 46%. Inhibitors were removed prior to fermentation by steam stripping. Major benefits were obtained by careful recycling of this yeast, which was shown to be tolerant both of high sugar concentrations and high alcohol concentrations. When sugar concentrations over 250 g/L (glucose:xylose 70:30) were fermented, ethanol became an inhibitor when its concentration reached 90 g/L. However, when the ethanol was removed by low-temperature vacuum distillation, fermentation continued and resulted in a yield of 0.50 g ethanol/g sugar consumed. Further improvement was achieved by combining enzyme saccharification of sugar oligomers with fermentation. This yeast is able to ferment both hexoses and pentoses simultaneously, efficiently, and rapidly. Present indications are that it is well suited to industrial operations wherever hexoses and pentoses are both to be fermented to ethanol, for example, in wood hydrolysates. (Refs. 6).

Yu, S.; Wayman, M.; Parekh, S.K.

1987-06-01

235

Screening of Fungi Capable of Degrading Lignocellulose from Plantation Forests  

OpenAIRE

In an effort to prevent forest fires after the clear cutting of plantation forests, fungi capable of degrading lignocelluloses were isolated to make a fertilizer from the logging waste. Seventy five fungal species were isolated from fruiting bodies and mycelia in plantation forests of South and North Sumatera, Indonesia. Sixty three of the fungi were identified based on the appearance and morphological characteristics of their fruiting bodies and mycelia, as Pycnoporus sanguineus, Dacryopinax...

Djarwanto; Tachibana, S.

2009-01-01

236

Lignocellulosic biomass utilization toward biorefinery : technologies, products and perspectives  

OpenAIRE

Lignocellulosic biomass wastes (LBW) are generated and accumulated in large amounts around the world every year. The disposal of large amounts of such wastes in the nature may cause environmental problems, affecting the quality of the soil, lakes and rivers. In order to avoid these problems, efforts have been directed to use LBW in a biorefinery to maximize the reutilization of these wastes with minimal or none production of residual matter. Through biorefiner...

Mussatto, Solange I.

2014-01-01

237

Role of lignin in the enzymatic hydrolysis of lignocellulose  

OpenAIRE

Characterization, understanding and overcoming barriers of enzymatic hydrolysis of different raw materials is essential for the development of economically competitive processes based on enzymatic treatments. This work focused on factors relevant for the improvement of enzymatic hydrolysis of lignocellulose raw materials derived from softwood. The major interest of the work was in lignin. Specific areas addressed were the role of lignin in the unproductive binding of cellulases, which restric...

Palonen, Hetti

2004-01-01

238

A method for rapid determination of sugars in lignocellulose prehydrolyzate  

OpenAIRE

A simple and rapid dual-wavelength spectroscopic method is used for simultaneous determination of pentoses and hexoses in the prehydrolyzate from lignocellulosic biomass. The method is based on the following reaction mechanism: in the solution of hydrochloric acid, phloroglucinol gives color reaction with sugars or their degradation products, showing maximum absorbance at 553 nm and 410 nm. Based on dual-wavelength spectrophotometric measurement, the pentoses and hexoses can separately ...

Congcong Chi; Hou-min Chang; Zhijian Li; Hasan Jameel; Zeng Zhang

2013-01-01

239

Proteins for breaking barriers in lignocellulosic bioethanol production.  

Science.gov (United States)

Reduction in fossil fuel consumption by using alternate sources of energy is a major challenge facing mankind in the coming decades. Bioethanol production using lignocellulosic biomass is the most viable option for addressing this challenge. Industrial bioconversion of lignocellulosic biomass, though possible now, is not economically viable due to presence of barriers that escalate the cost of production. As cellulose and hemicellulose are the major constituents of terrestrial biomass, which is available in massive quantities, hydrolysis of cellulose and hemicellulose by the microorganisms are the most prominent biochemical processes happening in the earth. Microorganisms possess different categories of proteins associated with different stages of bioethanol production and a number of them are already found and characterized. Many more of these proteins need to be identified which suit the specificities needed for the bioethanol production process. Discovery of proteins with novel specificities and application of genetic engineering technologies to harvest the synergies existing between them with the aim to develop consolidated bioprocess is the major direction of research in the future. In this review, we discuss the different categories of proteins used for bioethanol production in the context of breaking the barriers existing for the economically feasible lignocellulosic bioethanol production. PMID:25692949

Ulaganathan, Kandasamy; Goud, Burragoni S; Reddy, Mettu M; Kumar, Vanaparthi P; Balsingh, Jatoth; Radhakrishna, Surabhi

2015-01-01

240

Spent fuel shipping cask  

International Nuclear Information System (INIS)

A shipping cask for spent or failed nuclear fuel assemblies is described. The cask has a generally cylindrical stainless steel enclosure with a thick stainless steel slab welded to one end, a thick stainless steel closure removably sealed to the other end, a sheath of lead surrounding the cylindrical wall, separate tanks for neutron absorbing liquid surrounding the lead sheath and balsa wood impact absorbers on the exterior of the cask. The cask is also provided with pressure relief and drain valves housed in cavities in the steel for protection and trunnions specially arranged to facilitate handling. (U.S.)

241

Bioconversion of lignocellulosic biomass: biochemical and molecular perspectives.  

Science.gov (United States)

In view of rising prices of crude oil due to increasing fuel demands, the need for alternative sources of bioenergy is expected to increase sharply in the coming years. Among potential alternative bioenergy resources, lignocellulosics have been identified as the prime source of biofuels and other value-added products. Lignocelluloses as agricultural, industrial and forest residuals account for the majority of the total biomass present in the world. To initiate the production of industrially important products from cellulosic biomass, bioconversion of the cellulosic components into fermentable sugars is necessary. A variety of microorganisms including bacteria and fungi may have the ability to degrade the cellulosic biomass to glucose monomers. Bacterial cellulases exist as discrete multi-enzyme complexes, called cellulosomes that consist of multiple subunits. Cellulolytic enzyme systems from the filamentous fungi, especially Trichoderma reesei, contain two exoglucanases or cellobiohydrolases (CBH1 and CBH2), at least four endoglucanases (EG1, EG2, EG3, EG5), and one beta-glucosidase. These enzymes act synergistically to catalyse the hydrolysis of cellulose. Different physical parameters such as pH, temperature, adsorption, chemical factors like nitrogen, phosphorus, presence of phenolic compounds and other inhibitors can critically influence the bioconversion of lignocellulose. The production of cellulases by microbial cells is governed by genetic and biochemical controls including induction, catabolite repression, or end product inhibition. Several efforts have been made to increase the production of cellulases through strain improvement by mutagenesis. Various physical and chemical methods have been used to develop bacterial and fungal strains producing higher amounts of cellulase, all with limited success. Cellulosic bioconversion is a complex process and requires the synergistic action of the three enzymatic components consisting of endoglucanases, exoglucanases and beta-glucosidases. The co-cultivation of microbes in fermentation can increase the quantity of the desirable components of the cellulase complex. An understanding of the molecular mechanism leading to biodegradation of lignocelluloses and the development of the bioprocessing potential of cellulolytic microorganisms might effectively be accomplished with recombinant DNA technology. For instance, cloning and sequencing of the various cellulolytic genes could economize the cellulase production process. Apart from that, metabolic engineering and genomics approaches have great potential for enhancing our understanding of the molecular mechanism of bioconversion of lignocelluloses to value added economically significant products in the future. PMID:18338189

Kumar, Raj; Singh, Sompal; Singh, Om V

2008-05-01

242

Centralised spent fuel storage  

International Nuclear Information System (INIS)

France has a large nuclear power programme with about 50 nuclear power plants generating roughly 1300t of spent fuel a year. She has decided to continue reprocessing and recycling the recovered plutonium. This is being done for LWR fuels at La Hague, where the existing plant has been already carried out prompt reprocessing of more than 1300t. Two additional large 800tU/year plants, UP3 and UP2 800, will be on line in 1988 and 1991 respectively, to accommodate domestic fuel and meet the needs of foreign clients. To receive these fuels, a major spent fuel reception and storage programme has been implemented at La Hague. This facility is described and each stage from reception and unloading and storage in pools is explained. At La Hague there is dry reception for unloading the fuels into the new pools. For smaller storage capacities, dry storage is cheaper but for large capacities the pool is less expensive. Loading and unloading can be automated. Centralised storage prior to reprocessing reduces the amount of handling and reshuffling required. (UK)

243

Uses of mechanically separated chicken meat for production from protein hydrolysates different proteolytic enzymes  

Directory of Open Access Journals (Sweden)

Full Text Available The use of hydrolyzed protein, derived from animal and vegetable sources, in specific formulations, is an area of growing interest. The aim of this study was to develop different powder hydrolysates with high protein value, from the enzymatic hydrolysis of mechanically deboned meat (MDM, a byproduct of the poultry industry, which can be a low-cost source for the production of these hydrolysates. The raw material used was frozen poultry mechanically deboned meat (MDM purchased from an abattoir in southern Brazil, before use it was thawed under refrigeration and homogenized in a processor by 2 minutes. Three commercial enzymes were used, Papain, Protamex® and Flavourzyme®. The hydrolysis occurred in a thermostatized bath with temperature, time and pH controlled. Proximal composition of the raw material and lyophilized hydrolysates, control analysis such as hydrolysis degree of hydrolysis, protein, total solids, ash and amino acid characterization of the hydrolysates were performed. The results were evaluated by analysis of variance and Tukey’s averages test. The hydrolyzed obtained from the papain enzyme showed the best behavior, followed by Protamex and Flavourzyme. The hydrolysates from papain enzyme had higher protein content, soluble solids and lower ash content compared to other hydrolysates. The amino acid composition showed that the hydrolyzate from papain has a closer composition to what is recommended by the control organs. It was concluded that the protein hydrolysates obtained from mechanically deboned chicken had high protein content characterizing them as a promising raw material in the formulation of special diets.

Mari Silvia Rodrigues de Oliveira

2014-02-01

244

Antioxidant and antimicrobial activity of lecithin free egg yolk protein preparation hydrolysates obtained with digestive enzymes  

Directory of Open Access Journals (Sweden)

Full Text Available ABSTRACT:Several biological activities have now been associated with egg protein- derived peptides, including antihypertensive, antimicrobial, immunomodulatory, anticancer and antioxidantactivities, highlighting the importance of these biopeptides in human health, and disease prevention and treatment. Special attention has been given to peptides with antioxidant and antimicrobial activities as a new source of natural preservatives in food industry. In this study, the antioxidant properties of the egg-yolk protein by-product (YP hydrolysates were evaluated based on their radical scavenging capacity (DPPH, Fe2+chelating effect and ferric reducing power (FRAP. Furthermore, antimicrobial properties of obtained hydrolysates against Bacillus species were studied. The degrees (DHs of hydrolysis for 4h hydrolysates were: 19.1%, 13.5% and 13.0%, for pepsin, chymotrypsin and trypsin, respectively. Pepsin was the most effective in producing the free amino groups (1410.3 ?molGly/g. The RP-HPLC profiles of the protein hydrolysates showed differences in the hydrophobicity of the generated peptides.Trypsin hydrolysate obtained after 4h reaction demonstrated the strongest DPPH free radical scavenging activity (0.85 µmol Troloxeq/mg. Trypsin and chymotrypsin hydrolysates obtained after 4h reaction exhibited 4 times higher ferric reducing capacity than those treated bypepsin. The hydrolysis products obtained from YP exhibited significant chelating activity. The 4h trypsin hydrolysate exhibited weak antimicrobial activity against B. subtilis B3; B. cereus B512; B. cereus B 3p and B. laterosporum B6.

Aleksandra Zambrowicz

2012-12-01

245

[Functional properties and possible uses of a hydrolysate of pepitona (Arca zebra) in the preparation of foods].  

Science.gov (United States)

The present study revealed that the drum-drying and spray-drying procedures used on the pepitona (Arca zebra) hydrolysate, as well as the storage time, exert a deteriorative significant effect on the functional properties of both hydrolysates. The greatest and more significant losses of the majority of such properties occur during the first two months of storage period. Thus, in the case of foaming capacity, losses ranging from 17% to 34% were detected in the drum-dried hydrolysate, and of 38% to 49% in the hydrolysate dehydrated using a spray drier, during the first two months of storage. The emulsifying capacity was also altered in 14% of the hydrolysate dehydrated in a drum drier, and in 25% of the hydrolysate dehydrated using a spray drier. Sensory evaluation tests demonstrated the potential of both hydrolysates for use as supplements of conventional foods such as cookies and extruded products. PMID:3842930

Arbej, J; Luna, G

1985-12-01

246

Enhancement of glycerol production with ram horn hydrolysate by yeast  

International Nuclear Information System (INIS)

The potential use of ram horn hydrolysate (RHH) as a supplement for enhancement of glycerol production by Saccharomyces cerevisiae was studied. For this purpose, first, RHH was produced. Ram horns were hydrolyzed by treating with acid (6 N H2SO4), and the RHH was obtained. The contents of protein, nitrogen, ash, some minerals, total sugars, total lipids and amino acids of RHH were determined. With the addition of RHH to the fermentation medium with a final concentration of 4% (optimal concentration), the glycerol value reached a maximum value of 9.4 g l-1, which is 47% higher than that of the control experiment. The addition of 4% (v/v) RHH enhanced the glycerol accumulation, reduced the residual sugar concentration and stimulated yeast growth. Adding 4% RHH had no adverse effects on the cells of S. cerevisiae. As a result, RHH was found to be suitable as a valuable supplement for glycerol production in the batch fermentation

247

System and method for conditioning a hardwood pulp liquid hydrolysate  

Science.gov (United States)

A system and method for hardwood pulp liquid hydrolysate conditioning includes a first evaporator receives a hardwood mix extract and outputting a quantity of vapor and extract. A hydrolysis unit receives the extract, hyrolyzes and outputs to a lignin separation device, which separates and recovers a quantity of lignin. A neutralization device receives extract from the lignin separation device and a neutralizing agent, producing a mixture of solid precipitate and a fifth extract. The solid precipitate is removed from the fifth extract. A second evaporator removes a quantity of acid from the fifth extract in a vapor form. This vapor may be recycled to improve total acid recovery or discarded. A desalination device receives the diluted extract, separates out some of the acid and salt and outputs a desalinated solution.

Waite, Darrell M; Arnold, Richard; St. Pierre, James; Pendse, Hemant P; Ceckler, William H

2013-12-17

248

Xylan-hydrolysing enzymes of the yeast Pichia stipitis  

Energy Technology Data Exchange (ETDEWEB)

Two xylanolytic enzymes, xylanase and {beta}-xylosidase from the yeast Pichia stipitis were purified to homogeneity and characterized. Both enzymes are secreted into the culture medium upon growth on xylan. The xylanase is a glycoprotein with an approximate molecular mass of 43 kDa. The N-linked carbohydrate content was estimated to be 26% by endoglycosidase H digestion. The {beta}-xylosidase protein has a molecular mass of 37 kDa as determined by sodium dodecyl sulphate gel electrophoresis. Synthesis of xylanase was found to be inducible by xylan and repressible by xylose and glucose. By contrast, {beta}-xylosidase is synthesized constitutively to a considerable degree. The purified {beta}-xylosidase is able to hydrolyse aryl-{beta}-D-glucosides with an even higher rate than {beta}-xylosides. Thus, this enzyme may not be a specific component of the xylan-degrading system of P. stipitis. (orig.).

Oezcan, S.; Koetter, P.; Ciriacy, M. (Duesseldorf Univ. (Germany). Inst. fuer Mikrobiologie)

1991-11-01

249

Spent fuel management in Japan  

International Nuclear Information System (INIS)

In Japan 52 commercial nuclear power units are now operated, and the total power generation capacity is about 45 GWe. The cumulative amount of spent fuel arising is about 13,500 tU as of March 1997. Spent fuel is reprocessed, and recovered nuclear materials are to be recycled in LWRs and FBRs. In February 1997 short-term policy measures were announced by the Atomic Energy Commission, which addressed promotion of reprocessing programme in Rokkasho, plutonium utilization in LWRs, spent fuel management, backend measures and FBR development. With regard to the spent fuel management, the policy measures included expansion of spent fuel storage capacity at reactor sites and a study on spent fuel storage away from reactor sites, considering the increasing amount of spent fuel arising. Research and development on spent fuel storage has been carried out, particularly on dry storage technology. Fundamental studies are also conducted to implement the burnup credit into the criticality safety design of storage and transportation casks. Rokkasho reprocessing plant is being constructed towards its commencement in 2003, and Pu utilization in LWRs will be started in 1999. Research and development of future recycling technology are also continued for the establishment of nuclear fuel cycle based on FBRs and LWRs. (author)

250

Effects of gamma irradiation on the decomposition and biodegradability of lignocellulose  

International Nuclear Information System (INIS)

The study of effects of a pretreatment by gamma radiation on radioactive lignocellulose from poplar-tree and on subsequent biodegradation by fungi is realized for residues and soluble products. Measurement before and after treatment, of cellulose accessibility to an exogen cellulase shows the interest of irradiation in transformation processes of lignocellulosic products

251

Structural reorganisation of cellulose fibrils in hydrothermally deconstructed lignocellulosic biomass and relationships with enzyme digestibility  

OpenAIRE

Background: The investigation of structural organisation in lignocellulose materials is important to understand changes in cellulase accessibility and reactivity resulting from hydrothermal deconstruction, to allow development of strategies to maximise bioethanol process efficiencies. To achieve progress, wheat straw lignocellulose and comparative model wood cellulose were characterised following increasing severity of hydrothermal treatment. Powder and fibre wide-angle X-ray diff...

Ibbett, Roger; Gaddipati, Sanyasi; Hill, Sandra; Tucker, Greg

2013-01-01

252

Effect of Lignocellulose Related Compounds on Microalgae Growth and Product Biosynthesis: A Review  

OpenAIRE

Microalgae contain valuable compounds that can be harnessed for industrial applications. Lignocellulose biomass is a plant material containing in abundance organic substances such as carbohydrates, phenolics, organic acids and other secondary compounds. As growth of microalgae on organic substances was confirmed during heterotrophic and mixotrophic cultivation, lignocellulose derived compounds can become a feedstock to cultivate microalgae and produce target compounds. In this review, differe...

Krystian Miazek; Claire Remacle; Aurore Richel; Dorothee Goffin

2014-01-01

253

Advanced spent fuel storage pools  

International Nuclear Information System (INIS)

Full text: Spent fuel from Power Reactors is currently stored either in at-reactor pools or in independent spent fuel storage installations (ISFSI) using wet or dry storage technology. During the past 15 years, storage capacity of at reactor pools was increased using high density spent fuel storage technology. To achieve maximum capacity, storage racks were replaced in many of the power reactors in operation at least once, some of them went through even various reracking cycles. Independent spent fuel storage installations were established either at the site of power reactors of away from them. They use either storage pools or dry technology, the latter in form of metal casks and concrete silos or vaults. Storage of spent fuel from power reactors must be safe for the public and must protect the environment from its radioactive content. For this purpose, adequate regulation was developed and is available to be applied. However, advances in fuel and core design as well the need for extended storage periods require frequent re-assessment of the available spent fuel storage technology. Improved fuel utilization leads to elevated burn-up resulting in higher heat generation of the spent fuel in the longer term. Also spent MOX fuel generates considerable more heat than spent uranium fuel unloaded from the power reactors 15 years ago. As most of the mechanisms which could endanger fuel integrity are temperature dependent, effective heat removal is one of the challenges spent at removal is one of the challenges spent fuel storage systems have to face. In order to make most efficient use out of high density storage equipment, designer want to take credit from the actual burn-up of the spent fuel. Existing methodology to analyze burn-up credited spent fuel storage racks for criticality safety is being further developed to be applied in the design of dual-purpose casks or multi-purpose-canisters. For poisoned high density storage equipment, long term stability of the material as well as efficient neutron absorption is required. Degrading absorbers which contaminate the coolant of fuel pools and primary circuits and fuel assemblies getting stuck in swollen storage cells are well known problems which already caused considerable headaches to many operators and still continue to do so. Although limited in boron content, borated stainless steel has extensively proved as sufficiently effective and extremely stable neutron poison material. Over and above the basic requirements for maximum safety for operators and the public, logistic in fuel reception is an important aspect to be addressed with the design of independent spent fuel storage facilities. The aspect to keep the operators exposure to radiation as low as reasonably achievable requires expeditious reception of spent fuel and its transfer to the dedicated storage location. Independent wet storage facilities are known for many years to comply best with most of the expectations as described above. However, the assumption to need active cooling systems and to generate secondary waste had caused vendors and users to look favorably at dry storage systems. Despite the remarkable development achieved in dry storage technology, most of the spent fuel generated up to now is stored in fuel pools, either at the reactors or in independent installations. One of the latest achievements in wet storage technology is used in Framatome-ANP's wet storage facility design as currently being performed for the new spent fuel pool building to be constructed at the Goesgen Nuclear Power Station in Switzerland. The advanced design of this independent spent fuel storage facility provides a passive cooling system which reliably removes the heat generated by the spent fuel by natural circulation through air cooled heat exchangers. This progressive design makes extensive use of well balanced safety technology with largely passive safety features developed for Framatome-ANP's Boiling Water Reactor SWR1000. Clearly designed to enable the enforcement of strict foreign material exclusion strategies and state of the

254

Chemical and ultrastructural studies of lignocellulose biodegradation during Agaricus bisporus cultivation.  

Science.gov (United States)

During Agaricus bisporus cultivation, lignocellulose degradation is the result of the activity of both the mushroom and microbial communities developed during the composting. To investigate the lignocellulose degradation in detail from the beginning to the end of the process, the functional groups of cellulose, hemicellulose, and lignin have been studied with Fourier transform infrared spectroscopy and the morphological changes of lignocelluloses were elucidated with scanning electron microscopy. The aperture of lignin and cellulose increased to enable the mycelia of A. bisporus to penetrate into the medium and to degrade lignocelluloses in a more direct way. The chemical structure changes implied a preferential use of lignin that could make for better use of cellulose to boost growth of A. bisporus. Changes in chemical structure together with ultrastructural changes induced by the microbial flora during cultivation substrate production by the composting substrate are important in promoting the utilization of lignocelluloses by A. bisporus. PMID:24033911

Zhang, Rui; Wang, Hexiang; Liu, Qinghong; Ng, TziBun

2014-01-01

255

Fungal degradation of lignocellulosic residues: An aspect of improved nutritive quality.  

Science.gov (United States)

Abstract Microbial degradation of lignocellulosic materials brings a variety of changes in their bio-physicochemical properties. Lower digestibility of various agricultural residues can be enhanced by microbial treatment. White rot fungi are the potential candidates, which can improve the nutritional quality of lignocellulosic residues by degrading lignin and converting complex polysaccharides into simple sugars. Changes in physical qualities of lignocellulosics that is texture, colour and aroma have been an interesting area of study along with chemical properties. Degradation of lignocellulose not only upgrades the quality of degraded biomass, but helps simultaneous production of different commercial enzymes and other by products of interest. The review is focused on fungal degradation of lignocellulosics, resultant changes in physicochemical properties and nutritional value. PMID:23855359

Sharma, Rakesh Kumar; Arora, Daljit Singh

2015-02-01

256

Radical scavenging and amino acid profiling of wedge clam, Donax cuneatus (Linnaeus) protein hydrolysates.  

Science.gov (United States)

Body, foot and viscera of Donax cuneatus (Linnaeus) were hydrolyzed using commercial proteases (pepsin, trypsin and papain) and tested for their antioxidant activity by DPPH scavenging ability and reducing power assays. In comparison between all the hydrolysates, papain viscera (28.513?±?0.165 & 0.186?±?0.008) and foot (33.567?±?0.132 & 0.166?±?0.013) hydrolysates showed highest DPPH and reducing power ability respectively. The active hydrolysates were purified with DEAE- cellulose followed by Sephadex G-25 columns connected to FPLC. Further, the isolated active fractions were loaded onto HPLC for their amino acid profiling and found with the presence of potential amino acids viz., histidine, cysteine, alanine etc. These results suggest that the isolated antioxidant peptide from viscera and foot hydrolysate of D. cuneatus can be used in treating human diseases where free radicals and oxidative damage are involved. PMID:25477664

Nazeer, R A; Saranya, M A V; Naqash, Shabeena Yousuf

2014-12-01

257

Ethanol production from marine algal hydrolysates using Escherichia coli KO11.  

Science.gov (United States)

Algae biomass is a potential raw material for the production of biofuels and other chemicals. In this study, biomass of the marine algae, Ulva lactuca, Gelidium amansii,Laminaria japonica, and Sargassum fulvellum, was treated with acid and commercially available hydrolytic enzymes. The hydrolysates contained glucose, mannose, galactose, and mannitol, among other sugars, at different ratios. The Laminaria japonica hydrolysate contained up to 30.5% mannitol and 6.98% glucose in the hydrolysate solids. Ethanogenic recombinant Escherichia coli KO11 was able to utilize both mannitol and glucose and produced 0.4g ethanol per g of carbohydrate when cultured in L. japonica hydrolysate supplemented with Luria-Bertani medium and hydrolytic enzymes. The strategy of acid hydrolysis followed by simultaneous enzyme treatment and inoculation with E. coli KO11 could be a viable strategy to produce ethanol from marine alga biomass. PMID:21640583

Kim, Nag-Jong; Li, Hui; Jung, Kwonsu; Chang, Ho Nam; Lee, Pyung Cheon

2011-08-01

258

THE EFFECT OF ENZYMATIC HYDROLYSIS ON THE PROPERTIES OF PROTEIN HYDROLYSATE FROM PADDY MUSHROOM  

Directory of Open Access Journals (Sweden)

Full Text Available Protein hydrolysate was prepared from Paddy (Volvariella volvaceae mushroom. Hydrolysis uses commercially protease available Protamex ™ with enzyme concentration of 0.1% (w/w. Hydrolysis was performed at three different temperatures (room temperature, 40 °C, and 50 °C with different incubation periods (60, 90, and 120 minutes. Enzyme inactivation was done in 90 °C for 3 minutes. Yield and degree of hydrolysis ranged from 94.76% to 99.55% and 19.06% to 24.59%. Protein solubility was about 89–11,8%. The longer time of hydrolysis, the darker the color of protein hydrolysate. Protein hydrolysate which has hydrolysis at 50 °C for 120 minutes has the highest protein yield and the best sensory properties: 4.76 (taste liking, 3.68 (aroma liking, and 4.56 (overall liking. However, this protein hydrolysate has the potential for application as an ingredient in formulated diets.

Tamtarini

2010-11-01

259

Partially hydrolysed guar gum supplemented comminuted chicken diet in persistent diarrhoea: a randomised controlled trial  

OpenAIRE

Background: Partially hydrolysed guar gum (Benefiber) added to a diet is fermented in the colon, producing short chain fatty acids, which improve intestinal function, including colonic salt and water absorption.

Alam, N.; Meier, R.; Sarker, S.; Bardhan, P.; Schneider, H.; Gyr, N.

2005-01-01

260

Gross and true ileal digestible amino acid contents of several animal body proteins and their hydrolysates.  

Science.gov (United States)

Amino acid compositions of ovine muscle, ovine myofibrillar protein, ovine spleen, ovine liver, bovine blood plasma, bovine blood globulins and bovine serum albumin and the amino acid compositions and in vivo (laboratory rat) true ileal amino acid digestibilities of hydrolysates (sequential hydrolysis with Neutrase, Alcalase and Flavourzyme) of these protein sources were determined. True ileal amino acid digestibility differed (P<0.05) among the seven protein hydrolysates. The ovine myofibrillar protein and liver hydrolysates were the most digestible, with a mean true ileal digestibility across all amino acids of 99%. The least digestible protein hydrolysate was bovine serum albumin with a comparable mean true ileal digestibility of 93%. When the digestible amino acid contents were expressed as proportions relative to lysine, considerable differences, across the diverse protein sources, were found in the pattern of predicted absorbed amino acids. PMID:23567135

Cui, J; Chong, B; Rutherfurd, S M; Wilkinson, B; Singh, H; Moughan, P J

2013-07-01

261

Ethanol Production from Nondetoxified Dilute-Acid Lignocellulosic Hydrolysate by Cocultures of Saccharomyces cerevisiae Y5 and Pichia stipitis CBS6054  

OpenAIRE

Saccharomyces cerevisiae Y5 (CGMCC no. 2660) and Issatchenkia orientalis Y4 (CGMCC no. 2159) were combined individually with Pichia stipitis CBS6054 to establish the cocultures of Y5 + CBS6054 and Y4 + CBS6054. The coculture Y5 + CBS6054 effectively metabolized furfural and HMF and converted xylose and glucose mixture to ethanol with ethanol concentration of 16.6?g/L and ethanol yield of 0.46?g ethanol/g sugar, corresponding to 91.2% of the maximal theoretical value in synthetic medium. A...

Ping Wan; Dongmei Zhai; Zhen Wang,; Xiushan Yang; Shen Tian

2012-01-01

262

Study of lignocellulose components for production of lactic acid  

Energy Technology Data Exchange (ETDEWEB)

Lactic acid promises to be an important chemical feedstock in the future for the production of biodegradable and biocompatible polymers. About half of the current US consumption is imported to meet the escalating demand from both the food and chemical industries. The potential future market for polylactide products would further stress the domestic capacity of lactic acid production. Renewable resources such as lignocellulosic crops and wastes are abundant and could be utilized for the production of important fuels and chemicals. This would not only reduce our dependence on limited reserves of fossil fuels but also alleviate the environmental burden of waste accumulation and disposal.

Padukone, N.; Schmidt, S.L.; Goodman, B.J.; Wyman, C.E. [National Renewable Energy Lab., Golden, CO (United States)

1993-12-31

263

A comparative study of the hydrolysis of gamma irradiated lignocelluloses  

Scientific Electronic Library Online (English)

Full Text Available The effect of high-dose irradiation as a pretreatment method on two common lignocellulosic materials; hardwood (Khaya senegalensis) and softwood (Triplochiton scleroxylon) were investigated by assessing the potential of cellulase enzyme derived from Aspergillus flavus Linn isolate NSPR 101 to hydrol [...] yse the materials. The irradiation strongly affected the materials, causing the enzymatic hydrolysis to increase by more than 3 fold. Maximum digestibility occurred in softwood at 40kGy dosage of irradiation, while in hardwood it was at 90kGy dosage. The results also showed that, at the same dosage levels (p

E., Betiku; O. A., Adetunji; T. V., Ojumu; B. O., Solomon.

2009-06-01

264

Synergism of glycoside hydrolase secretomes from two thermophilic bacteria cocultivated on lignocellulose.  

Science.gov (United States)

Two cellulolytic thermophilic bacterial strains, CS-3-2 and CS-4-4, were isolated from decayed cornstalk by the addition of growth-supporting factors to the medium. According to 16S rRNA gene-sequencing results, these strains belonged to the genus Clostridium and showed 98.87% and 98.86% identity with Clostridium stercorarium subsp. leptospartum ATCC 35414(T) and Clostridium cellulosi AS 1.1777(T), respectively. The endoglucanase and exoglucanase activities of strain CS-4-4 were approximately 3 to 5 times those of strain CS-3-2, whereas the ?-glucosidase activity of strain CS-3-2 was 18 times higher than that of strain CS-4-4. The xylanase activity of strain CS-3-2 was 9 times that of strain CS-4-4, whereas the ?-xylosidase activity of strain CS-4-4 was 27 times that of strain CS-3-2. The enzyme activities in spent cultures following cocultivation of the two strains with cornstalk as the substrate were much greater than those in pure cultures or an artificial mixture of samples, indicating synergism of glycoside hydrolase secretomes between the two strains. Quantitative measurement of the two strains in the cocultivation system indicated that strain CS-3-2 grew robustly during the initial stages, whereas strain CS-4-4 dominated the system in the late-exponential phase. Liquid chromatography-tandem mass spectrometry analysis of protein bands appearing in the native zymograms showed that ORF3880 and ORF3883 from strain CS-4-4 played key roles in the lignocellulose degradation process. Both these open reading frames (ORFs) exhibited endoglucanase and xylanase activities, but ORF3880 showed tighter adhesion to insoluble substrates at 4, 25, and 60°C owing to its five carbohydrate-binding modules (CBMs). PMID:24532065

Zhang, Kundi; Chen, Xiaohua; Schwarz, Wolfgang H; Li, Fuli

2014-04-01

265

Characterization and Potential Use of Cuttlefish Skin Gelatin Hydrolysates Prepared by Different Microbial Proteases  

OpenAIRE

Composition, functional properties, and in vitro antioxidant activities of gelatin hydrolysates prepared from cuttlefish skin were investigated. Cuttlefish skin gelatin hydrolysates (CSGHs) were obtained by treatment with crude enzyme preparations from Bacillus licheniformis NH1, Bacillus mojavensis A21, Bacillus subtilis A26, and commercial alcalase. All CSGHs had high protein contents, 74.3–78.3%, and showed excellent solubility (over 90%). CSGH obtained by alcalase demonstrated high anti...

Mourad Jridi; Imen Lassoued; Rim Nasri; Mohamed Ali Ayadi; Moncef Nasri; Nabil Souissi

2014-01-01

266

Optimization of the Preparation of Fish Protein Anti-Obesity Hydrolysates Using Response Surface Methodology  

OpenAIRE

The enzymatic condition for producing the anti-obesity hydrolysates from fish water-soluble protein was optimized with the aid of response surface methodology, which also derived a statistical model for experimental validation. Compared with neutral protease, papain and protamex, the porcine pancreas lipase inhibitory rate of hydrolysates from fish water-soluble protein was higher with alkaline protease. Results showed that the model terms were significant, the terms of lack of fit were not s...

Jinju Wang; Chen Peng; Yanping Wang; Liyuan Liu

2013-01-01

267

Industrial scale chromatographic separation of valuable compounds from biomass hydrolysates and side streams  

OpenAIRE

Carbohydrates are composed of a number of various monosaccharides, glucose being the most abundant. Some of the monosaccharides are valuable compounds used in the food and pharmaceutical industries. They can be separated from biomass hydrolysates e.g. by chromatographic methods. In this thesis, chromatographic separation of valuable compounds using ion exchange resins was studied on an industrial scale. Of special interest were rare monosaccharides in biomass hydrolysates. A novel chroma...

Saari, Pia

2011-01-01

268

Preparation and Characteristic of Iron-Binding Peptides from Shrimp Processing Discards Hydrolysates  

OpenAIRE

The aim of this study was focused on preparation of iron-binding peptides from Shrimp Processing Discards (SPD) hydrolysate using response surface methodology (RSM) and characteristic of the iron-peptides complex. Six kinds of protease (tyrpsin, pepsin, protmex, flavourzyme, neutrase and alcalase) were used to hydrolysis the SPD protein and the trypsin hydrolysate showed the highest iron-binding activity. The factorial design experiments showed that pH, trypsin concentration and hydrolysis ti...

Zhang-yan Ren; Guang-rong Huang; Jia-xin Jiang; Wen-wei Chen

2011-01-01

269

In Vitro Binding Capacity of Bile Acids by Defatted Corn Protein Hydrolysate  

Directory of Open Access Journals (Sweden)

Full Text Available Defatted corn protein was digested using five different proteases, Alcalase, Trypsin, Neutrase, Protamex and Flavourzyme, in order to produce bile acid binding peptides. Bile acid binding capacity was analyzed in vitro using peptides from different proteases of defatted corn hydrolysate. Some crystalline bile acids like sodium glycocholate, sodium cholate and sodium deoxycholate were individually tested using HPLC to see which enzymes can release more peptides with high bile acid binding capacity. Peptides from Flavourzyme defatted corn hydrolysate exhibited significantly (p

Pierre Claver Irakoze

2011-02-01

270

HYDROLYSIS OF WHEAT STRAW HEMICELLULOSE AND DETOXIFICATION OF THE HYDROLYSATE FOR XYLITOL PRODUCTION  

OpenAIRE

Xylitol can be obtained from wheat straw hemicellulose containing a high content of xylan. This study describes a new system of hydrolysis, utilizing a mixed solution of formic acid and hydrochloric acid in which xylan can be hydrolyzed effectively. The hydrolysate contains a high content of formic acid, which markedly inhibits the fermentation. One of the most efficient methods for removing inhibiting compounds is treatment of the hydrolysate with ion-exchange resins. Formate can be removed ...

Junping Zhuang; Ying Liu; Zhen Wu; Yong Sun; Lu Lin

2009-01-01

271

Disposal of spent nuclear fuel  

Energy Technology Data Exchange (ETDEWEB)

This report addresses the topic of the mined geologic disposal of spent nuclear fuel from Pressurized Water Reactors (PWR) and Boiling Water Reactors (BWR). Although some fuel processing options are identified, most of the information in this report relates to the isolation of spent fuel in the form it is removed from the reactor. The characteristics of the waste management system and research which relate to spent fuel isolation are discussed. The differences between spent fuel and processed HLW which impact the waste isolation system are defined and evaluated for the nature and extent of that impact. What is known and what needs to be determined about spent fuel as a waste form to design a viable waste isolation system is presented. Other waste forms and programs such as geologic exploration, site characterization and licensing which are generic to all waste forms are also discussed. R and D is being carried out to establish the technical information to develop the methods used for disposal of spent fuel. All evidence to date indicates that there is no reason, based on safety considerations, that spent fuel should not be disposed of as a waste.

1979-12-01

272

Advanced spent fuel storage pools  

International Nuclear Information System (INIS)

Spent fuel from power reactors is currently stored either in at-reactor spent fuel storage pools or in independent spent fuel storage installations using wet or dry storage technology. Most of the spent fuel generated up to now is stored in spent fuel pools. The assumption that wet storage is expensive due to the need of active cooling systems and generation of waste had caused vendors to look favorable at dry storage systems. One of the latest achievements in wet storage technology is used in FRAMATOME ANP's wet storage facility as currently designed for the new spent fuel storage building at Goesgen Nuclear Power Station Switzerland. It provides a passive cooling system which reliably removes the heat generated by the spent fuel by natural circulation through air cooled heat exchanger. Due to the passive nature of the operating system, the number of active components which require maintenance is substantially reduced. The frequency of maintenance activities can be determined under consideration of actual usage due to advanced acquisition methodology of operational data. This usually leads to a considerable reduction of human intervention and the time needed to act in radiation areas reducing considerably waste generation and dose burden to personnel. Due to the fact that maintenance and repair concepts are available, it can be predicted, if correctly applied, such pools to be operable for extended periods of time. (author)

273

Spent fuel treatment in Japan  

International Nuclear Information System (INIS)

In Japan, 52 nuclear power reactors are operating with a total power generation capacity of 45 GWe. The cumulative amount of spent fuel arising, as of March 1998, is about 14,700 W. Spent fuel is reprocessed and recovered nuclear materials are to be recycled in LWRs and FBRs. Pu utilization in LWRs will commence in 1999. In January 1997, short-term policy measures were announced by the Atomic Energy Commission, which addressed promotion of the reprocessing programme in Rokkasho, plutonium utilization in LWRs, spent fuel management, back-end measures and FBR development. With regard to the spent fuel management, the policy measures included expansion of spent fuel storage capacity at reactor sites and a study on spent fuel storage away-from-reactor sites, considering the increasing amount of spent fuel arising. Valuable experience was been accumulated at the Tokai Reprocessing Plant (TRP), from the start of hot operation in 1977 up to now. The role of the TRP will be changed from an operation-oriented to a more R and D oriented facility, when PNC is reorganized into the new organization JNC. The Rokkasho reprocessing plant is under construction and is expected to commence operation in 2003. R and D of future recycling technologies is also continued for the establishment of a nuclear fuel cycle based on FBRs and LWRs. (author)

274

Antioxidant Activities of Protein Hydrolysates from Little Hairtail (Trichiurus haumela of East China Sea  

Directory of Open Access Journals (Sweden)

Full Text Available This study investigated antioxidant properties of the little hairtail (Trichiurus haumela protein hydrolysates obtained by commercial protease of Alcalase through using various antioxidant assays, including reducing power and free radical scavenging activities. The molecular mass distribution of hydrolysates was also examined to evaluate their relationship with antioxidant activity. The results showed that little hairtail protein hydrolysates had good ability to donate electron or hydrogen and scavenge DPPH, hydroxyl and superoxide anion radicals. The highest value of reducing power and radical scavenging activities was 1.89, 46.15% (DPPH radical, 75.65% (hydroxyl radical and 82.5% (superoxide anion radical, respectively. The reducing power and free radical scavenging activities of little hairtail protein hydrolysates were related to hydrolysis time to some extent. The molecular mass distribution of hydrolysates showed that their molecular mass was between 337 and 6007Da, which indicated that little hairtail protein hydrolysates were mainly composed of low molecular peptides with antioxidant activity. Conclusively, the little hairtail protein was a good natural source for producing antioxidants, which could be used as antioxidant ingredient with potential applications in various food products.

Ting Jin

2015-02-01

275

Antioxidative efficacy of alkali-treated tilapia protein hydrolysates: a comparative study of five enzymes.  

Science.gov (United States)

The antioxidant activities of alkali-treated tilapia protein hydrolysates were determined by their ability to inhibit the formation of lipid hydroperoxides (PV) and thiobarbituric acid reactive substances (TBARS) in a washed muscle model system and by their ability to inhibit DPPH free radicals and chelate ferrous ion in an aqueous solution. Protein isolates were prepared from tilapia white muscle using alkali solubilization at pH 11.0 and reprecipitation at pH 5.5. Protein hydrolysates were prepared by hydrolyzing the isolates using five different enzymes, Cryotin F, Protease A Amano, Protease N Amano, Flavourzyme, and Neutrase, to 7.5, 15, and 25% degrees of hydrolysis (DH). All of the protein hydrolysates significantly (pFlavourzyme and Neutrase were least effective in inhibiting the development of TBARS and PV, whereas in an aqueous solution, hydrolysates prepared using Flavourzyme were most effective in scavenging DPPH radicals and chelating ferrous ions. Enzymatic hydrolysis decreased the size of tilapia protein hydrolysates and, in general, tilapia protein hydrolysates with low molecular weights were better antioxidants than those with high molecular weights. PMID:18247531

Raghavan, Sivakumar; Kristinsson, Hordur G

2008-02-27

276

Assessment of spent fuel cooling  

International Nuclear Information System (INIS)

The paper presents the methodology, the findings, and the conclusions of a study that was done by the Nuclear Regulatory Commission's Office for Analysis and Evaluation of Operational Data (AEOD) on loss of spent fuel pool cooling. The study involved an examination of spent fuel pool designs, operating experience, operating practices, and procedures. AEOD's work was augmented in the area of statistics and probabilistic risk assessment by experts from the Idaho Nuclear Engineering Laboratory. Operating experience was integrated into a probabilistic risk assessment to gain insight on the risks from spent fuel pools

277

Assessment of spent fuel cooling  

Energy Technology Data Exchange (ETDEWEB)

The paper presents the methodology, the findings, and the conclusions of a study that was done by the Nuclear Regulatory Commission`s Office for Analysis and Evaluation of Operational Data (AEOD) on loss of spent fuel pool cooling. The study involved an examination of spent fuel pool designs, operating experience, operating practices, and procedures. AEOD`s work was augmented in the area of statistics and probabilistic risk assessment by experts from the Idaho Nuclear Engineering Laboratory. Operating experience was integrated into a probabilistic risk assessment to gain insight on the risks from spent fuel pools.

Ibarra, J.G.; Jones, W.R.; Lanik, G.F. [and others

1997-02-01

278

Lignocellulose degradation by the isolate of Streptomyces griseorubens JSD-1.  

Science.gov (United States)

Streptomyces griseorubens JSD-1 is an isolate that can utilize lignocellulose (straw) as its sole carbon source for growth, and these lignocellulolytic genes involved in this biotransformation are expected to be crucial. However, little is known about the genetic basis related to this process. To further investigate the lignocellulose-degrading mechanisms, genome sequencing was carried out using MiSeq platform. After obtaining its draft genome, the key lignocellulolytic genes such as multicopper oxidase, exo-1, 4-?-glucanase, endo-1,4-?-glucanase, and ?-xylosidase were identified and characterized. Multiple sequence alignments were performed to find out the identities of these analyzed proteins to those of their similar species. Signal peptide cleavage sites were predicted by SignalP 4.1 to reflect the cellular localization of their mature proteins. Besides, predicted 3D structures of these proteins were modeled by Phyre2, which showed to be highly identical to the templates in the PDB database. Finally, quantitative real-time PCR revealed that expression levels of all analyzed enzymes were significantly and generally up-regulated during the whole cultivation, indicating that they all contributed to the biodegradation. PMID:25452226

Feng, Haiwei; Sun, Yujing; Zhi, Yuee; Mao, Liang; Luo, Yanqing; Wei, Xing; Zhou, Pei

2015-03-01

279

Covalent Immobilization of ?-Glucosidase on Magnetic Particles for Lignocellulose Hydrolysis  

DEFF Research Database (Denmark)

?-Glucosidase hydrolyzes cellobiose to glucose and is an important enzyme in the consortium used for hydrolysis of cellulosic and lignocellulosic feedstocks. In the present work, ?-glucosidase was covalently immobilized on non-porous magnetic particles to enable re-use of the enzyme. It was found that particles activated with cyanuric chloride and polyglutaraldehyde gave the highest bead-related immobilized enzyme activity when tested with p-nitrophenyl-?-D-glucopyranoside (104.7 and 82.2 U/g particles, respectively). Furthermore, the purified ?-glucosidase preparation from Megazyme gave higher bead-related enzyme activities compared to Novozym 188 (79.0 and 9.8 U/g particles, respectively). A significant improvement in thermal stability was observed for immobilized enzyme compared to free enzyme; after 5 h (at 65 °C), 36 % of activity remained for the former, while there was no activity in the latter. The performance and recyclability of immobilized ?-glucosidase on more complex substrate (pretreated spruce)was also studied. It was shown that adding immobilized ?-glucosidase (16 U/g dry matter) to free cellulases (8 FPU/g dry matter) increased the hydrolysis yield of pretreated spruce from ca. 44 % to ca. 65 %. In addition, it was possible to re-use the immobilized ?-glucosidase in the spruce and retain activity for at least four cycles. The immobilized enzyme thus shows promise for lignocellulose hydrolysis.

Alftrén, Johan; Hobley, Timothy John

2013-01-01

280

Energy and Environmental Performance of Bioethanol from Different Lignocelluloses  

Directory of Open Access Journals (Sweden)

Full Text Available Climate change and the wish to reduce the dependence on oil are the incentives for the development of alternative energy sources. The use of lignocellulosic biomass together with cellulosic processing technology provides opportunities to produce fuel ethanol with less competition with food and nature. Many studies on energy analysis and life cycle assessment of second-generation bioethanol have been conducted. However, due to the different methodology used and different system boundary definition, it is difficult to compare their results. To permit a direct comparison of fuel ethanol from different lignocelluloses in terms of energy use and environmental impact, seven studies conducted in our group were summarized in this paper, where the same technologies were used to convert biomass to ethanol, the same system boundaries were defined, and the same allocation procedures were followed. A complete set of environmental impacts ranging from global warming potential to toxicity aspects is used. The results provide an overview on the energy efficiency and environmental performance of using fuel ethanol derived from different feedstocks in comparison with gasoline.

Gjalt Huppes

2010-01-01

281

Lignocellulose pretreatment severity – relating pH to biomatrix opening  

DEFF Research Database (Denmark)

In cellulose-to-ethanol processes a physico-chemical pretreatment of the lignocellulosic feedstock is a critical prerequisite for increasing the amenability of the cellulose to enzymatic attack. Currently published pretreatment strategies span over a wide range of reaction conditions involving different pH values, temperatures, types of catalysts, and holding times. The consequences of the pretreatment on lignocellulosic biomass are described with special emphasis on the chemical alterations of the biomass during pretreatment, especially highlighting the significance of the pretreatment pH. We present a new illustration of the pretreatment effects encompassing the differential responses to the pH and temperature. A detailed evaluation of the use of severity factor calculations for pretreatment comparisons signifies that the multiple effects of different pretreatment factors on the subsequent monosaccharide yields after enzymatic hydrolysis cannot be reliably compared by a one-dimensional severity factor, evenwithin the same type of pretreatment strategy. However, a quantitative comparison of published data for wheat straw pretreatment illustrates that there is some correlation between the hydrolysis yields (glucose, xylose) and the pretreatment pH, but no correlation with the pretreatment temperature (90–200 °C). A better recognition and understanding of the factors affecting biomatrix opening, and use of more standardized evaluation protocols, will allow for the identification of new pretreatment strategies that improve biomass utilization and permit rational enzymatic hydrolysis of the cellulose.

Pedersen, Mads; Meyer, Anne S.

2010-01-01

282

Enzymatic hydrolysis of lignocellulosic biomass from Onopordum nervosum.  

Science.gov (United States)

Some properties of the cellulolytic complex obtained from Trichoderma reesei QM 9414 grown on Solka floc as carbon source and its ability to hydrolyze the lignocellulosic biomass of Onopordum nervosum Boiss were studied. The optimum enzyme activity was found at temperatures between 50 and 55 degrees C and pH ranging from 4.3 to 4.8. Hydrolysis of 4-nitropnenyl-beta-D-glucopyranoside (4-NPG) and cellobiose by the beta-glucosidase of the complex, showed competitive inhibition by glucose with a K(i) value of 0.8 mM for 4-NPG and 2. 56 mM for cellobiose. Enzymatic hydrolysis yield of Onopordum nervosum, evaluated as glucose production after 48 h, showed a threefold increase by pretreating the lignocellulosic substrate with alkali. When the loss of glucose incurred by de pretreatment was taken into account, a 160% increase in the final cellulose to glucose conversion was found to be due to the pretreatment. PMID:18584755

Martín, C; Negro, M J; Alfonsel, M; Sáez, R

1988-07-20

283

LWR spent fuel storage technology  

International Nuclear Information System (INIS)

By 2003, the year the U.S. Department of Energy (DOE) predicts a repository will be available, 58 domestic commercial nuclear-power plant units are expected to run out of wet storage space for LWR spent fuel. To alleviate this problem, utilities implemented advances in storage methods that increase storage capacity as well as reduced the rate of generating spent fuel. Those advances are discussed. They include transshipping spent-fuel assemblies between pools within the same utility system, reracking pools to accommodate additional spent-fuel assemblies, taking credit for fuel burnup in pool storage rack design, extending fuel burnup, rod consolidation, and dry storage. The focus of this paper is on advances in rod consolidation and dry storage

284

Spent fuel management in Canada  

International Nuclear Information System (INIS)

The current status of storage, transport and disposal/recycle of spent fuel is described. Virtually all of the spent fuel is now stored at the reactor, mostly in water pools, but also in concrete containers. Future plans are for the development of a transportation prototype and for the development of a disposal concept based on deep underground implacement in crystalline rock. (author). 5 figs, 2 tabs

285

Transportation of spent MTR fuels  

Energy Technology Data Exchange (ETDEWEB)

This paper gives an overview of the various aspects of MTR spent fuel transportation and provides in particular information about the on-going shipment of 4 spent fuel casks to the United States. Transnucleaire is a transport and Engineering Company created in 1963 at the request of the French Atomic Energy Commission. The company followed the growth of the world nuclear industry and has now six subsidiaries and affiliated companies established in countries with major nuclear programs.

Raisonnier, D.

1997-08-01

286

Adapting wood hydrolysate barriers to high humidity conditions.  

Science.gov (United States)

The incorporation of layered silicates in bio-based barrier films resulted in lower water vapor permeability, and significantly lowered oxygen permeability at a relative humidity (RH) as high as 80%, with reduced moisture sensitivity of the wood hydrolysate (WH) based films. The applicability of WH based films was accordingly extended over a wider relative humidity condition range. Crude aqueous process liquor, the WH, was extracted from hardwood and utilized as a feed-stock for films without any upgrading pretreatment, yet producing superior oxygen barrier performance compared to partially upgraded WH and highly purified hemicelluloses. Films composed of crude WH and either one of two types of naturally occurring layered silicates, montmorillonite (MMT) or talc, as mineral additives, were evaluated with respect to oxygen and water vapor permeability, morphological, tensile and dynamic thermo-mechanical properties. Films with an oxygen permeability as low as 1.5 (cm(3)?m)/(m(2)daykPa) at 80% RH was achieved. PMID:24188847

Yaich, Anas Ibn; Edlund, Ulrica; Albertsson, Ann-Christine

2014-01-16

287

Management of HFIR spent fuel  

International Nuclear Information System (INIS)

The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) has been unable to ship its spent fuel off-site for reprocessing since 1985. The HFIR storage pools are expected to fill up by the end of 1994. If a management alternative to existing HFIR pool storage is not identified and implemented by that time, the HFIR will be forced to shut down. This study identified and investigated five alternatives to managing the HFIR spent fuel, to determine the feasibility of implementing each in time to prevent shutdown of the HFIR: (1) increasing HFIR pool storage capacity, (2) storing the spent fuel at another ORNL pool, (3) storing the spent fuel in one or more hot cells at ORNL, (4) shipping the spent fuel off-site for reprocessing or storage elsewhere, and (5) installing a dedicated dry storage facility at ORNL. Of the alternatives investigated, only two could prevent the shutdown of the HFIR in the near term: increasing HFIR pool storage capacity or shipping the spent fuel off-site. Both options have been vigorously pursued because neither is assured of success, and at least one of the options must be successfully implemented if the HFIR is to continue operation. In addition, a third option was selected for implementation as an intermediate-term storage solution: installing a dedicated dry storage facility for the HFIR. An intermediate-term storage solution is needed because neither of the short-term solutions could ensure long-term continued operation of the HFIR

288

HFIR spent fuel management alternatives  

International Nuclear Information System (INIS)

The High Flux Isotope Reactor (HFIR) at Martin Marietta Energy Systems' Oak Ridge National Laboratory (ORNL) has been unable to ship its spent fuel to Savannah River Site (SRS) for reprocessing since 1985. The HFIR storage pools are expected to fill up in the February 1994 to February 1995 time frame. If a management altemative to existing HFIR pool storage is not identified and implemented before the HFIR pools are full, the HFIR will be forced to shut down. This study investigated several alternatives for managing the HFIR spent fuel, attempting to identify options that could be implemented before the HFIR pools are full. The options investigated were: installing a dedicated dry cask storage facility at ORNL, increasing HFIR pool storage capacity by clearing the HFIR pools of debris and either close-packing or stacking the spent fuel elements, storing the spent fuel at another ORNL pool, storing the spent fuel in one or more hot cells at ORNL, and shipping the spent fuel offsite for reprocessing or storage elsewhere

289

Preparation of Low-phenylalanine Whey Hydrolysates, Using Papain and Pancreatin Immobilized on Activated Carbon and Alumina  

OpenAIRE

This study involves the preparation of whey hydrolysates with low phenylalanine (Phe) content aiming the treatment of phenylketonuria. For hydrolysing the proteins, two enzymes were used, papain and pancreatin, in an immobilized form, on Activated Carbon (AC) and alumina (AL) and three enzyme: substrate ratios (E:S) were tested for each enzyme. Activated carbon was used to remove Phe from hydrolysates. The second order spectrophotometry was used to evaluate the efficiency of Phe removal as we...

Silva, Viviane D. M.; Marco, Leticia M.; Afonso, Wendel O.; Lopes, Daniella C. F.; JoseN. Januario; Aguiar, Marcos J. B.; Starling, Ana Lucia P.; Silvestre, Marialice P. C.

2007-01-01

290

Evaluation of nutrient supplementation to charcoal-treated and untreated rice straw hydrolysate for xylitol production by Candida guilliermondii  

OpenAIRE

Xylitol was produced by Candida guilliermondii from charcoal-treated and untreated rice straw hemicellulosic hydrolysate with or without nutrients (ammonium sulphate, calcium chloride, rice bran extract). Both, xylitol yield and volumetric productivity decreased significantly when the nutrients were added to treated and untreated hydrolysates. In the treated hydrolysate, the efficiency of xylose conversion to xylitol was 79% when the nutrients were omitted. The results demonstrated that rice ...

Solange Inês Mussatto; Inês Conceição Roberto

2005-01-01

291

The effects of dietary marine protein hydrolysates on the development of sea bass larvae, Dicentrarchus labrax, and associated microbiota  

OpenAIRE

Protein hydrolysate is an essential component of dry starter diets for fish larvae, as promoting healthy development. Peptides are also suitable substrates for many intestinal microbes. Five experimental diets were compared to a control diet (CONT) supplemented with a commercial fish protein hydrolysate. Each diet contained one marine protein hydrolysate, which differed by the proportion of di- and tri-peptides, and by raw materials. Two diets (HYD4 and HYD5) stimulated larval growth compared...

Delcroix, Jeremy; Gatesoupe, Joel; Desbruye?res, Elisabeth; Huelvan, Christine; Le Delliou, Herve; Le Gall, Marie-madeleine; Quazuguel, Patrick; Mazurais, David; Zambonino, Jose-luis

2014-01-01

292

Angiotensin-I-Converting Enzyme Inhibitory and Antioxidant Activities of Protein Hydrolysate from Muscle of Barbel (Barbus callensis)  

OpenAIRE

The present study investigated angiotensin-I-converting enzyme (ACE) inhibitory and antioxidant activities of barbel muscle protein hydrolysate prepared with Alcalase. The barbel muscle protein hydrolysate displayed a high ACE inhibitory activity (C I 50 = 0.92 mg/mL). The antioxidant activities of protein hydrolysate at different concentrations were evaluated using various in vitro antioxidant assays, including 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical method and reducing power assay. The...

Assaad Sila; Anissa Haddar; Oscar Martinez-Alvarez; Ali Bougatef

2013-01-01

293

Spent Nuclear Fuel project, project management plan  

International Nuclear Information System (INIS)

The Hanford Spent Nuclear Fuel Project has been established to safely store spent nuclear fuel at the Hanford Site. This Project Management Plan sets forth the management basis for the Spent Nuclear Fuel Project. The plan applies to all fabrication and construction projects, operation of the Spent Nuclear Fuel Project facilities, and necessary engineering and management functions within the scope of the project

294

Biostimulant action of a plant-derived protein hydrolysate produced through enzymatic hydrolysis.  

Science.gov (United States)

The aim of this study was to evaluate the biostimulant action (hormone like activity, nitrogen uptake, and growth stimulation) of a plant-derived protein hydrolysate by means of two laboratory bioassays: a corn (Zea mays L.) coleoptile elongation rate test (Experiment 1), a rooting test on tomato cuttings (Experiment 2); and two greenhouse experiments: a dwarf pea (Pisum sativum L.) growth test (Experiment 3), and a tomato (Solanum lycopersicum L.) nitrogen uptake trial (Experiment 4). Protein hydrolysate treatments of corn caused an increase in coleoptile elongation rate when compared to the control, in a dose-dependent fashion, with no significant differences between the concentrations 0.75, 1.5, and 3.0 ml/L, and inodole-3-acetic acid treatment. The auxin-like effect of the protein hydrolysate on corn has been also observed in the rooting experiment of tomato cuttings. The shoot, root dry weight, root length, and root area were significantly higher by 21, 35, 24, and 26%, respectively, in tomato treated plants with the protein hydrolysate at 6 ml/L than untreated plants. In Experiment 3, the application of the protein hydrolysate at all doses (0.375, 0.75, 1.5, and 3.0 ml/L) significantly increased the shoot length of the gibberellin-deficient dwarf pea plants by an average value of 33% in comparison with the control treatment. Increasing the concentration of the protein hydrolysate from 0 to 10 ml/L increased the total dry biomass, SPAD index, and leaf nitrogen content by 20.5, 15, and 21.5%, respectively. Thus the application of plant-derived protein hydrolysate containing amino acids and small peptides elicited a hormone-like activity, enhanced nitrogen uptake and consequently crop performances. PMID:25250039

Colla, Giuseppe; Rouphael, Youssef; Canaguier, Renaud; Svecova, Eva; Cardarelli, Mariateresa

2014-01-01

295

Biostimulant action of a plant-derived protein hydrolysate produced through enzymatic hydrolysis  

Science.gov (United States)

The aim of this study was to evaluate the biostimulant action (hormone like activity, nitrogen uptake, and growth stimulation) of a plant-derived protein hydrolysate by means of two laboratory bioassays: a corn (Zea mays L.) coleoptile elongation rate test (Experiment 1), a rooting test on tomato cuttings (Experiment 2); and two greenhouse experiments: a dwarf pea (Pisum sativum L.) growth test (Experiment 3), and a tomato (Solanum lycopersicum L.) nitrogen uptake trial (Experiment 4). Protein hydrolysate treatments of corn caused an increase in coleoptile elongation rate when compared to the control, in a dose-dependent fashion, with no significant differences between the concentrations 0.75, 1.5, and 3.0 ml/L, and inodole-3-acetic acid treatment. The auxin-like effect of the protein hydrolysate on corn has been also observed in the rooting experiment of tomato cuttings. The shoot, root dry weight, root length, and root area were significantly higher by 21, 35, 24, and 26%, respectively, in tomato treated plants with the protein hydrolysate at 6 ml/L than untreated plants. In Experiment 3, the application of the protein hydrolysate at all doses (0.375, 0.75, 1.5, and 3.0 ml/L) significantly increased the shoot length of the gibberellin-deficient dwarf pea plants by an average value of 33% in comparison with the control treatment. Increasing the concentration of the protein hydrolysate from 0 to 10 ml/L increased the total dry biomass, SPAD index, and leaf nitrogen content by 20.5, 15, and 21.5%, respectively. Thus the application of plant-derived protein hydrolysate containing amino acids and small peptides elicited a hormone-like activity, enhanced nitrogen uptake and consequently crop performances. PMID:25250039

Colla, Giuseppe; Rouphael, Youssef; Canaguier, Renaud; Svecova, Eva; Cardarelli, Mariateresa

2014-01-01

296

Percutaneous removal of pulmonary artery emboli with hydrolyser catheter in pigs  

International Nuclear Information System (INIS)

To evaluate the efficacy and safety of the Hydrolyser catheter for per,cutaneous treatment of massive pulmonary embolism in pigs. Twelve pigs, each weighing between 55 kg and 89 kg, were used. Radio-opaque 9 cm x 0.8 cm and 4.5 cm x 0.8 cm clots, produced by mixing pig blood with iodinated contrast agent in vacutainers, were injected via the jugular vein until central pulmonary embolism (main and proximal lobar arteries) was obtained with significant systemic and pulmonary hemodynamic modifications. From a femoral approach, the 7-French Hydrolyser thrombectomy catheter was run over a 0.025-inch (0.64-mm) guide wire to remove the pulmonary emboli. Hemodynamic, gasometric and angiographic monitoring was performed before and after treatment. The procedure's safety and completeness of emboli removal was assessed by cardiopulmonary autopsy. Three of the 12 pigs died during embolization. Thrombectomy was therefore performed in 9, and central emboli could be obtained in 7 of the 9. The Hydrolyser could be manipulated only in central pulmonary arteries and could aspirate only central emboli in 5 of the 7 pigs that had them. Despite minimal angiographic improvement seen in these 5, there was no significant hemodynamic and gasometric improvement after treatment. The procedure induced an increase in free hemoglobin blood levels. Autopsies revealed an average of 2 endothelial injuries per pig (mainly adherent endocardial thrombi) in both nontreated (n = 3) and Hydrolyser-treated nontreated (n = 3) and Hydrolyser-treated (n = 9) groups. The Hydrolyser thrombectomy catheter can be promptly positioned and easily steered in central pulmonary arteries. It can be used to partially remove central emboli, but not peripheral pulmonary emboli. Most of the injuries observed may not have been strictly related to Hydrolyser use. The pig might not be a suitable animal model for treatment of massive pulmonary embolism. (author)

297

[Preparation and nutritional characteristics of a hydrolysate from pepitona (Arca zebra)].  

Science.gov (United States)

Two soluble products resulting from the hydrolysis of pepitona (Arca zebra) were prepared as flour. Papain at its optimum hydrolysis conditions, previously established, was the enzyme used (40 degrees C for two hours at a pH of 7 in the proportion of 0.3% weight/enzyme/100 g meat). The hydrolysate obtained was then subjected to two different dehydration techniques: drum drying at 121 degrees C and 18 seconds retention, and spray drying at 101 degrees C and 40 psi pressure. The products were then stored for a five-month period at a temperature of 25 degrees C +/- 2 degrees C, time during which chemical determinations were performed in both hydrolysates. Findings showed that the time of storage does exert a significant effect of deterioration on the products. The greater and more significant quality losses occur during the first two months. The dehydration techniques used also affect significantly the soluble nitrogen content, and non-protein nitrogen and soluble solids content, as well as color of pepitona hydrolysates. Spray-drying dehydration technique does not have a significant deteriorating effect. Biological studies undertaken demonstrated that the quality of both hydrolysates is satisfactory from the nutritional and amino acid composition points of view. A protein efficiency ratio (PER) of 2.27 and 2.29 was determined for the hydrolysate dehydrated by drum drier and for the dehydrated by spray drier, respectively. With regard to amino acid composition, both had satisfactory levels of essential amino acids, with a lysine content of 6.9 g/100 g protein for the hydrolysate dehydrated by drum drying, and 8.6 g/100 g protein for the other hydrolysate dehydrated by spray drying. PMID:3842922

Arbej, J; Luna, G

1985-12-01

298

The conversion of lignocellulosics to fermentable sugars - A survey of current research and applications to CELSS  

Science.gov (United States)

This report provides an overview options for converting lignocellulosics into fermentable sugars in CELSS. A requirement for pretreatment is shown. Physical-chemical and enzymatic hydrolysis processes for producing fermentable sugars are discussed. At present physical-chemical methods are the simplest and best characterized options, but enzymatic processes will be the likely method of choice in the future. The use of pentose sugars by microorganisms to produce edibles is possible. The use of mycelial food production on pretreated but not hydrolyzed lignocellulosics is also possible. Simple trade-off analyses to regenerate waste lignocellulosics for two pathways are made, one of which is compared to complete oxidation.

Petersen, Gene R.; Baresi, Larry

1990-01-01

299

Development of spent fuel remote handling technology  

Energy Technology Data Exchange (ETDEWEB)

Since the nation`s policy on spent fuel management is not finalized, the technical items commonly required for safe management and recycling of spent fuel - remote technologies of transportation, inspection, maintenance, and disassembly of spent fuel - are selected and pursued. In this regards, the following R and D activities are carried out : collision free transportation of spent fuel assembly, mechanical disassembly of spent nuclear fuel and graphical simulation of fuel handling / disassembly process. (author). 36 refs., 16 tabs., 77 figs

Yoon, Ji Sup; Park, B. S.; Park, Y. S.; Oh, S. C.; Kim, S. H.; Cho, M. W.; Hong, D. H

1997-12-01

300

Development of spent fuel remote handling technology  

International Nuclear Information System (INIS)

Since the nation's policy on spent fuel management is not finalized, the technical items commonly required for safe management and recycling of spent fuel - remote technologies of transportation, inspection, maintenance, and disassembly of spent fuel - are selected and pursued. In this regards, the following R and D activities are carried out : collision free transportation of spent fuel assembly, mechanical disassembly of spent nuclear fuel and graphical simulation of fuel handling / disassembly process. (author). 36 refs., 16 tabs., 77 figs

301

Comparative environmental performance of lignocellulosic ethanol from different feedstocks  

International Nuclear Information System (INIS)

A renewable biofuel economy is projected as a pathway to decrease dependence on fossil fuels as well as to reduce greenhouse gases (GHG) emissions. Ethanol produced on large-scale from lignocellulosic raw materials is considered the most potential next generation automotive fuel. In this paper, a Life Cycle Assessment model was developed to evaluate the environmental implications of the production of ethanol from five lignocellulosic materials: alfalfa stems, poplar, Ethiopian mustard, flax shives and hemp hurds and its use in passenger cars. Two ethanol-based fuel applications, E10 (a mixture of 10% ethanol and 90% gasoline by volume) and E85 (85% ethanol and 15% gasoline by volume) were assessed and the results were compared to those of conventional gasoline (CG) in an equivalent car. The environmental performance was assessed in terms of fossil fuels requirements, global warming, photochemical oxidant formation, acidification and eutrophication by means of the Life Cycle Assessment (LCA) methodology in order to identify the best environmental friendly lignocellulosic source. The results show that, compared to CG, life cycle greenhouse gases emissions are lower for etanol blends, specifically up to 145% lower for E85-fueled car derived from Ethiopian mustard. This crop is also the best option in terms of eutrophying emissions regardless the ratio of ethanol in the blend. In the remaining impact categories, other feedstocks are considered beneficial, that is, poplar re considered beneficial, that is, poplar in the case of photochemical oxidants formation and flax shives for acidification. Concerning fossil fuels requirements, decreases up to 10% and 63% for E10 and E85 derived from hemp hurds and Ethiopian mustard, respectively, were obtained. According to the results, the study clearly demonstrates the importance of using low intensive energy and high biomass yield crops. LCA procedure helps to identify the key areas in the ethanol production life cycle where the researchers and technicians need to work to improve the environmental performance. Technological development could help in lowering both the environmental impact and the prices of the ethanol fuels. (author)

302

Towards an Understanding of How Protein Hydrolysates Stimulate More Efficient Biosynthesis in Cultured Cells  

Science.gov (United States)

In the light of the growing demand for high quality plant-derived hydrolysates (i.e., HyPep™ and UltraPep™ series), Sheffield Bio-Science has developed a new hydrolysate platform that addresses the need for animal-free cell culture medium supplements while also minimizing variability concerns. The platform is based upon a novel approach to enzymatic digestion and more refined processing. At the heart of the platform is a rationally designed animal component-free (ACF) enzyme cocktail that includes both proteases and non-proteolytic enzymes (hydrolases) whose activities can also liberate primary components of the polymerized non-protein portion of the raw material. This enzyme system is added during a highly optimized process step that targets specific enzyme-substrate reactions to expand the range of beneficial nutritional factors made available to cells in culture. Such factors are fundamental to improving the bio-performance of the culture system, as they provide not merely growth-promoting peptides and amino acids, but also key carbohydrates, lipids, minerals, and vitamins that improve both rate and quality of protein expression, and serve to improve culture life due to osmo-protectant and anti-apoptotic properties. Also of significant note is that, compared to typical hydrolysates, the production process is greatly reduced and requires fewer steps, intrinsically yielding a better-controlled and therefore more reproducible product. Finally, the more sophisticated approach to enzymatic digestion renders hydrolysates more amenable to sterile filtration, allowing hydrolysate end users to experience streamlined media preparation and bioreactor supplementation activities. Current and future development activities will evolve from a better understanding of the complex interactions within a handful of key biochemical pathways that impact the growth and productivity of industrially relevant organisms. Presented in this chapter are some examples of the efforts that have been made so far to elucidate the mechanisms for the often dramatic benefits that hydrolysates can impart on cell culture processes. Given the variety of roles that hydrolysates likely play in each cell type, close collaboration between protein hydrolysate manufacturers and biopharmaceutical developers will continue to be critical to expanding the industry's knowledge and retaining hydrolysates as a tool for enhancing media formulations.

Siemensma, André; Babcock, James; Wilcox, Chris; Huttinga, Hans

303

Utilization of Lignocellulosic Waste for the Preparation of Nitrogenous Biofertilizer  

Directory of Open Access Journals (Sweden)

Full Text Available This work is a part of solid waste management project. Bagasse, a lignocellulosic waste of sugarcane industry was utilized for producing the nitrogenous biofertilizer. Nitrogen fixing free living bacteria were isolated from soil samples using dilution plate method. Selection of bacteria Azotobacter chroococcum was made due to its capability to survive and fix the maximum nitrogen as compared to other bacteria tested in a medium in which bagasse was the only carbon source. A. chroococcum, A. indicus and Azospirilum brasilense were tested for nitrogen fixation from 7 to 28 days. Maximum nitrogen fixed by these bacteria was 67.81, 28.00 and 43.20 mg/L respectively. Experimental results justified that bagasse biomass with A. chroococcum is a good source of nitrogen and organic matter, which can be utilized as a biofertilizer.

Farhat R. Malik

2001-01-01

304

Bioethanol from lignocellulose - pretreatment, enzyme immobilization and hydrolysis kinetics  

DEFF Research Database (Denmark)

Pretreatment and enzymatic hydrolysis are two of the processes involved in the production of cellulosic ethanol. Several pretreatment methods were proposed, however new pretreatment strategies to increase enzymetic hydrolysis efficiency are still under investigation. For enzymatic hydrolysis, the cost of enzyme is still the bottle neck, re-using the enzyme is apossible way to reduce the input of enzyme in the process. In the point view of engineering, the prediction of enzymatic hydrolysis kinetics under different substrate loading, enzyme combination is usful for process design. Therefore, several kinetic models were proposed previously. In view of the connetions between pretreatment and enzymatic hydrolysis. The hypotheses and objective of this PhD study consists of three parts: (1) Pretreatment of barley straw by 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac), which was done during 2009. Ionic liquid had been reported to be able to dissolve lignocellulose. However, as our knowledge, in all published researches, the concentration of lignocellulose in ionic liquid were low (5~10%). Besides, pretreatment time were long (from 1 hr to 1 day). Based on the hypothesis that the amount of ionic liquid and pretreatment time can be reduced, the influence of substrate concentration, pretreatment time and temperature were investigated and optimized. Pretreatment of barley straw by [EMIM]Ac, correlative models were constructed using 3 different pretreatment parameters (temperature, time, concentration of barley straw substrate) and sugar recoveries obtained following enzymatic hydrolysis. Elevated pretreatmenttemperature and longer pretreatment time favoured hydrolysis. However intensive pretreatment at high temperature also causes degradation of cellulose. In addition, [EMIM]Ac pretreated lignocellulose was found to stabilize and protect the enzymes at elevated temperatures. Therefore lower levels of enzymes were required to obtain similar hydrolytic efficiencies. Optimal pretreatment condition was found with the aid of models based on multiple linear regression. Consider the balanced against economic considerations, barley straw can be pretreated under 150°C for 50 min with dry matter of 20% (w/w). Glucose yield can be up to 70% after enzymatic hydrolysis. (2) Immobilization of ß-glucosidase (BG), which was done during 2010. One of the major bottlenecks in production of ethanol from lignocellulose is the required high cellulase enzyme dosages that increase the processing costs. One method to decrease the enzyme dosage is to re-use BG, which hydrolyze the soluble substrate cellobiose. Based on the hypothesis that immobilized BG can be re-used, how many times the enzyme could be recycled and how coupling with glutaraldehyde affected enzyme recovery after immobilization were investigated. Glutaraldehyde cross-linkedBG aggregates were entrapped in 3.75% calcium alginate. Glutaraldehyde inactivate enzyme activity but also reduce the leakage of enzyme from calcium alginate. Findings showed that more than 60% of enzymatic activity could be maintained under optimized immobilization condition. In order to evaluate stability, the immobilized enzymes were reused for the hydrolysis of Avicel. No significant loss of activity was observed up to 20th round. Similar glucose yields were obtained following enzymatic hydrolysis of hot water pretreated barley straw by immobilized and free BG. Finally, this is the first time that BG aggregates in a calcium alginate were visualized by confocallaser scanning microscope. The images prove that more BG aggregates were entrapped in the matrix when the enzyme was cross-linked by glutaraldehyde. (3) Validation and modification of a semimechanistic model, which was done during 2010 ~ 2012. A number of cellulosic hydrolysis kinetic models were proposed. Among the models, a simple and usful mathamatical model proposed by Kadam et al. (2004) has potential for supporting process design. However, like the other models, it was not validated intensivly, especially under high glucose concentration background and hi

Tsai, Chien Tai

2012-01-01

305

Effect of microaerobic fermentation in preprocessing fibrous lignocellulosic materials.  

Science.gov (United States)

Amending soil with organic matter is common in agricultural and logging practices. Such amendments have benefits to soil fertility and crop yields. These benefits may be increased if material is preprocessed before introduction into soil. We analyzed the efficiency of microaerobic fermentation (MF), also referred to as Bokashi, in preprocessing fibrous lignocellulosic (FLC) organic materials using varying produce amendments and leachate treatments. Adding produce amendments increased leachate production and fermentation rates and decreased the biological oxygen demand of the leachate. Continuously draining leachate without returning it to the fermentors led to acidification and decreased concentrations of polysaccharides (PS) in leachates. PS fragmentation and the production of soluble metabolites and gases stabilized in fermentors in about 2-4 weeks. About 2 % of the carbon content was lost as CO(2). PS degradation rates, upon introduction of processed materials into soil, were similar to unfermented FLC. Our results indicate that MF is insufficient for adequate preprocessing of FLC material. PMID:22639359

Alattar, Manar Arica; Green, Terrence R; Henry, Jordan; Gulca, Vitalie; Tizazu, Mikias; Bergstrom, Robby; Popa, Radu

2012-06-01

306

Ultrasound-assisted fractionation of the lignocellulosic material.  

Science.gov (United States)

In the present work the effectiveness of different lignocellulosic biomass fractionation processes based on ultrasounds technology was evaluated. Organosolv (acetic acid 60% v/v), alkaline (sodium hydroxide 7.5% w/w) and autohydrolysis treatments were applied at low temperature and the fractionation effectiveness was measured at different sonication conditions of the raw material. The obtained solid fractions were characterized using TAPPI standard methods, and the liquid fractions main components were quantified with the purpose of studying the effect that the treatment conditions had on the obtained by-products quality. Therefore, obtained lignin samples were characterized by ATR-IR spectroscopy and their thermal behaviour by TGA technique. The results showed that ultrasounds application improved the yield and selectivity of the studied processes and that the obtained lignin did not suffer significant modifications in its physicochemical properties. PMID:21377359

García, Araceli; Alriols, María González; Llano-Ponte, Rodrigo; Labidi, Jalel

2011-05-01

307

Thermogravimetric-mass spectrometric analysis on combustion of lignocellulosic biomass.  

Science.gov (United States)

Combustion characteristics of biomass main components and three lignocellulosic biomass (fir wood, eucalyptus wood and pine bark) were investigated by thermogravimetric analysis coupled with mass spectrometry. The combustion of biomass was divided into two main steps, devolatilization and char oxidation stage. Heating rate effect was also studied. Generally, the higher the heating rate, the higher the decomposition temperature. Furthermore, the weight loss rate decreased due to particle temperature gradients. Combustion kinetics were studied. Models based on reaction order (Oi), nucleation (Ni) and diffusion (Di) achieved the best fitting to the experimental data. Cellulose oxidation presented the highest activation energies. CO, CO2 and H2O were the main components evolved from combustion. Additionally, light hydrocarbons (CH4 and C2H5) were also present. Finally, nitrogen compounds were in a higher proportion than sulfur compounds being released as primary amines and NOx. PMID:23835261

López-González, D; Fernandez-Lopez, M; Valverde, J L; Sanchez-Silva, L

2013-09-01

308

Improved efficiency of butanol production by absorbed lignocellulose fermentation.  

Science.gov (United States)

Alkali-treated steam-exploded corn stover (SECSAT) was used as solid substrate for acetone-butanol-ethanol (ABE) production by absorbed lignocellulose fermentation (ALF) using Clostridium acetobutylicum ATCC 824. The ABE concentration in ALF culture had increased by 47% compared with that in submerged culture. More surprisingly, the acetone production was promoted and ethanol production was lower in the presence of SECSAT than that in its absence. ALF was also successfully in cofermentation of glucose and xylose, although decreased fermentability with an increase in the proportion of xylose. An invariable chemical composition and dry weight of SECSAT was found in ALF. Partial simultaneous saccharification and fermentation of SECSAT using a certain amount of cellulase could not only enhance the ABE concentration by 71%, but also significantly increase the area proportion of fiber cells in SECSAT from 53% to 90%, which would be an excellent paper making material. PMID:23085417

He, Qin; Chen, Hongzhang

2013-03-01

309

Experimental modelling of a pilot lignocellulosic pellets stove plant  

International Nuclear Information System (INIS)

Small-scale stoves, producing heat and hot water, are suited for domestic purposes. In order to optimise their efficiency when using lignocellulosic pellets, an important task is to do research on their real performance. The general behaviour depends on many operational factors (air flow and humidity, pressure, etc), dimension and pellet characteristics (moisture, size, raw material, density, friability, etc). In this paper, the first results and general performance of a 24 kW pellet fixed bed stove pilot plant are presented. The plant has been designed to study pellet combustion in the laboratory. The main targets are to reduce emissions of pollutants and to improve energy efficiency. Different situations can be simulated and tested due to its flexible design. Temperatures, pressures, flows and emissions are measured and analysed. An extensive study of different load conditions is presented through the application of both an experiment design technique and the later statistical analysis of the results. Fuel characterisation is also presented. (Author)

310

Development of a commercial enzymes system for lignocellulosic biomass saccharification  

Energy Technology Data Exchange (ETDEWEB)

DSM Innovation Inc., in its four year effort was able to evaluate and develop its in-house DSM fungal cellulolytic enzymes system to reach enzyme efficiency mandates set by DoE Biomass program MYPP goals. DSM enzyme cocktail is uniquely active at high temperature and acidic pH, offering many benefits and product differentiation in 2G bioethanol production. Under this project, strain and process development, ratio optimization of enzymes, protein and genetic engineering has led to multitudes of improvement in productivity and efficiency making development of a commercial enzyme system for lignocellulosic biomass saccharification viable. DSM is continuing further improvement by additional biodiversity screening, protein engineering and overexpression of enzymes to continue to further lower the cost of enzymes for saccharification of biomass.

Kumar, Manoj

2012-12-20

311

TPS/LDPE blends reinforced with lignocellulose fibers  

International Nuclear Information System (INIS)

Because of their abundance, availability, low abrasiveness and mechanical properties, cellulose fibers have been frequently chosen as reinforcing fillers in composites. Castor bean cake, the residue from biodiesel production, is rich in lignocellulose fibers and proteins. One of these proteins is ricin, a toxin protein. In this work, ricin was denatured by heat treatment in water at 90 deg C for 4 h. Thermoplastic starch (TPS), low density polyethylene (LDPE), maleated polyethylene (used as the compatibilizing agent), and an organophilic clay were processed in the presence of different contents of heat treated castor bean cake. Processing was carried out in a single-screw extruder, at 400 rpm, with heat zones at 130 deg C, 135 deg C, 135 deg C and 130 deg C (from feed zone to die end). The structural and mechanical properties of the resulting polymeric composites were investigated, and revealed the reinforcing effect of the partially purified cellulose fibers. (author)

312

Chickpea protein hydrolysate as a substitute for serum in cell culture.  

Science.gov (United States)

The growth of mammalian cells in vitro requires the use of rich culture media that are prepared by combining serum with specific nutrient formulations. Serum, the most expensive component of culture media, provides a complex mixture of growth factors and nutrients. Protein hydrolysates that can support in vitro cell growth and eliminate or reduce the need to use serum have been obtained from different sources. Here we describe the use of two food grade proteases to produce a chickpea protein hydrolysate that has been added to cell culture medium in order to determine whether it can be used as a substitute for serum. Medium containing the hydrolysate has been tested using two human cells lines: the monocytic THP-1 cell line which grows in suspension, and the epithelial Caco-2 cell line which grows as a monolayer. The chickpea protein hydrolysate was a good substitute for serum in the first case, but did not allow growth of Caco-2 cells. Supplementation of culture media with this inexpensive and safe hydrolysate would greatly reduce the cost of cell culture. PMID:19003183

Girón-Calle, Julio; Vioque, Javier; Pedroche, Justo; Alaiz, Manuel; Yust, María M; Megías, Cristina; Millán, Francisco

2008-07-01

313

Amino acid composition and functional properties of giant red sea cucumber ( Parastichopus californicus) collagen hydrolysates  

Science.gov (United States)

Giant red sea cucumber ( Parastichopus californicus) is an under-utilized species due to its high tendency to autolysis. The aim of this study was to evaluate the functional properties of collagen hydrolysates from this species. The degree of hydrolysis (DH), amino acid composition, SDS-PAGE, emulsion activity index (EAI), emulsion stability index (ESI), foam expansion (FE), and foam stability (FS) of hydrolysates were investigated. The effects of pH on the EAI, ESI FE and FS of hydrolysates were also investigated. The results indicated that the ? and ? 1 chains of the collagen were effectively hydrolyzed by trypsin at 50°c with an Enzyme/Substrate (E/S) ration of 1:20 (w:w). The DH of collagen was up to 17.3% after 3 h hydrolysis with trypsin. The hydrolysates had a molecular weight distribution of 1.1-17 kDa, and were abundant in glycine (Gly), proline (Pro), glutamic acid (Glu), alanine (Ala) and hydroxyproline (Hyp) residues. The hydrolysates were fractionated into three fractions ( 10 kDa), and the fraction of 3-10 kDa exhibited a higher EAI value than the fraction of > 10 kDa ( P 10 kDa had higher FE and FS values than other fractions ( P 10 kDa showed higher FE value, respectively. They are hoped to be utilized as functional ingredients in food and nutraceutical industries.

Liu, Zunying; Su, Yicheng; Zeng, Mingyong

2011-03-01

314

Amino acid composition and antioxidant activities of hydrolysates and peptide fractions from porcine collagen.  

Science.gov (United States)

The amino acid composition and antioxidant activities of different hydrolysates from porcine collagen were analyzed. The gelatin was hydrolyzed for antioxidative peptides with various proteases, namely papain, protease from bovine pancreas, protease from Streptomyces, and cocktail mixture of protease from bovine pancreas and protease from Streptomyces. The hydrolysates were assessed using methods of DPPH radical-scavenging ability, metal-chelating ability and lipid peroxidation inhibition activity. It was found that the collagen hydrolysates by different protease treatments had different amino acid compositions and antioxidant properties. However, the contents of Hyp and Pro were improved and the content of Gly was decreased in each collagen hydrolysate compared with collagen. The hydrolysate prepared with the cocktail mixture of proteases, which exhibited the highest antioxidant activity, was separated into 6 fractions by gel filtration chromatography. Fraction 2 was further separated by ion exchange chromatography. Fraction 2b with abundant basic amino acids and Fraction 2d which was slightly acidic fractions had higher radical-scavenging and metal-chelating activities, and both Fraction 2b and 2d contained more hydrophobic amino acids. The results confirmed that the antioxidative peptides were rich in Hyp, Pro and Gly, which accounted for half of amino acid composition. This article added further support to the preparation of natural antioxidative peptides from porcine skin collagen. PMID:23064526

Ao, Jing; Li, Bo

2012-10-01

315

Affinity purification of copper-chelating peptides from sunflower protein hydrolysates.  

Science.gov (United States)

Copper-chelating peptides were purified from sunflower protein hydrolysates by affinity chromatography using immobilized copper. A variety of protein hydrolysates were obtained by incubation with the proteases Alcalase and Flavourzyme for different periods of time. Chelating activity was indirectly determined by measuring the inhibitory effect of hydrolysates on the oxidation of beta-carotene by copper. Copper-binding peptides purified from the two hydrolysates that inhibited oxidation by copper the most contained 25.4 and 42.0% histidine and inhibited beta-carotene oxidation 8 and 3 times more than the original hydrolysates, which had 2.4 and 2.6% histidine, respectively. Thus, histidine content is not the only factor involved in antioxidant activity, and probably other factors such as peptide size and amino acid sequence are also important. This work shows that affinity chromatography can be used for the purification of copper-chelating peptides and probably other metals of nutritional interest such as calcium, iron, and zinc. In addition to their antioxidant potential, chelating peptides are of nutritional interest because they increase bioavailability of minerals. PMID:17636941

Megías, Cristina; Pedroche, Justo; Yust, Maria M; Girón-Calle, Julio; Alaiz, Manuel; Millan, Francisco; Vioque, Javier

2007-08-01

316

Enzymatic lignocellulose hydrolysis: Improved cellulase productivity by insoluble solids recycling  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background It is necessary to develop efficient methods to produce renewable fuels from lignocellulosic biomass. One of the main challenges to the industrialization of lignocellulose conversion processes is the large amount of cellulase enzymes used for the hydrolysis of cellulose. One method for decreasing the amount of enzyme used is to recycle the enzymes. In this study, the recycle of enzymes associated with the insoluble solid fraction after the enzymatic hydrolysis of cellulose was investigated for pretreated corn stover under a variety of recycling conditions. Results It was found that a significant amount of cellulase activity could be recovered by recycling the insoluble biomass fraction, and the enzyme dosage could be decreased by 30% to achieve the same glucose yields under the most favorable conditions. Enzyme productivity (g glucose produced/g enzyme applied increased between 30 and 50% by the recycling, depending on the reaction conditions. While increasing the amount of solids recycled increased process performance, the methods applicability was limited by its positive correlation with increasing total solids concentrations, reaction volumes, and lignin content of the insoluble residue. However, increasing amounts of lignin rich residue during the recycle did not negatively impact glucose yields. Conclusions To take advantage of this effect, the amount of solids recycled should be maximized, based on a given processes ability to deal with higher solids concentrations and volumes. Recycling of enzymes by recycling the insoluble solids fraction was thus shown to be an effective method to decrease enzyme usage, and research should be continued for its industrial application.

Weiss Noah

2013-01-01

317

Biodiesel from lignocellulosic biomass--prospects and challenges.  

Science.gov (United States)

Biodiesel can be a potential alternative to petroleum diesel, but its high production cost has impeded its commercialization in most parts of the world. One of the main drivers for the generation and use of biodiesel is energy security, because this fuel can be produced from locally available resources, thereby reducing the dependence on imported oil. Many countries are now trying to produce biodiesel from plant or vegetable oils. However, the consumption of large amounts of vegetable oils for biodiesel production could result in a shortage in edible oils and cause food prices to soar. Alternatively, the use of animal fat, used frying oils, and waste oils from restaurants as feedstock could be a good strategy to reduce the cost. However, these limited resources might not meet the increasing demand for clean, renewable fuels. Therefore, recent research has been focused the use of residual materials as renewable feedstock in order to lower the cost of producing biodiesel. Microbial oils or single cell oils (SCOs), produced by oleaginous microorganisms have been studied as promising alternatives to vegetable or seed oils. Various types of agro-industrial residues have been suggested as prospective nutritional sources for microbial cultures. Since the most abundant residue from agricultural crops is lignocellulosic biomass (LCB), this byproduct has been given top-priority consideration as a source of biomass for producing biodiesel. But the biological transformation of lignocellulosic materials is complicated due to their crystalline structure. So, pretreatment is required before they can be converted into fermentable sugar. This article compares and scrutinizes the extent to which various microbes can accumulate high levels of lipids as functions of the starting materials and the fermentation conditions. Also, the obstacles associated with the use of LCB are described, along with a potentially viable approach for overcoming the obstacles that currently preclude the commercial production of biodiesel from agricultural biomass. PMID:22475852

Yousuf, Abu

2012-11-01

318

SELF-ASSEMBLED LIGNOCELLULOSE MICELLES: A NEW GENERATION OF VALUE-ADDED FUNCTIONAL NANOSTRUCTURES  

Directory of Open Access Journals (Sweden)

Full Text Available Lignocellulose-based self-assembled micelles have emerged as a new generation of value-added functional nanostructures that show promise to address issues concerning the depletion of non-renewable resources; also these materials may contribute to the growing enthusiasm of utilizing biomass resources. Lignocellulose micelles can be conveniently prepared by self-assembly of amphiphilic lignocellulose derivatives in aqueous solution. They show great potential for applications in disparate fields, e.g. drug delivery, bioimaging diagnosis, sensing, nanoreacting, and so on. However, as a new research topic, a lot of research work would be needed to find out the critical structural factors that correlate with the formation, stability, morphology, and flexibility of lignocellulose micelles.

Xiaohui Wang Mail

2011-01-01

319

Enzyme Characterization of Cellulase and Hemicellulases Component Enzymes and Saccharification of Ionic Liquid Pretreated Lignocellulosic Biomass  

Science.gov (United States)

Lignocellulosic biomass is comprised of cellulose and hemicellulose, sources of polysaccharides, and lignin, a macromolecule with extensive aromaticity. Terrestrial biomass can provide a renewable carbon based feedstock for fuel and chemical production. However, recalcitrance of biomass to deconstru...

320

Thermogravimetric-mass spectrometric analysis of lignocellulosic and marine biomass pyrolysis.  

Science.gov (United States)

The pyrolysis characteristics of three lignocellulosic biomasses (fir wood, eucalyptus and pine bark) and a marine biomass (Nannochloropsis gaditana microalgae) were investigated by thermogravimetric analysis coupled with mass spectrometry (TGA-MS). Thermal degradation of lignocellulosic biomass was divided into four zones, corresponding to the decomposition of their main components (cellulose, hemicellulose and lignin) and a first step associated to water removal. Differences in volatile matter and cellulose content of lignocellulosic species resulted in different degradation rates. Microalgae pyrolysis occurred in three stages due to the main components of them (proteins), which are greatly different from lignocellulosic biomass. Heating rate effect was also studied. The main gaseous products formed were CO(2), light hydrocarbons and H(2)O. H(2) was detected at high temperatures, being associated to secondary reactions (char self-gasification). Pyrolysis kinetics were studied using a multiple-step model. The proposed model successfully predicted the pyrolytic behaviour of these samples resulting to be statistically meaningful. PMID:22297048

Sanchez-Silva, L; López-González, D; Villaseñor, J; Sánchez, P; Valverde, J L

2012-04-01

321

Room temperature ionic liquids as emerging solvents for the pretreatment of lignocellulosic biomass.  

Science.gov (United States)

Room temperature ionic liquids (RTILs) are emerging as attractive and green solvents for lignocellulosic biomass pretreatment. The unique solvating properties of RTILs foster the disruption of the 3D network structure of lignin, cellulose, and hemicellulose, which allows high yields of fermentable sugars to be produced in subsequent enzymatic hydrolysis. In the current review, we summarize the physicochemical properties of RTILs that make them effective solvents for lignocellulose pretreatment including mechanisms of interaction between lignocellulosic biomass subcomponents and RTILs. We also highlight several recent strategies that exploit RTILs and generate high yields of fermentable sugars suitable for downstream biofuel production, and address new opportunities for use of lignocellulosic components, including lignin. Finally, we address some of the challenges that remain before large-scale use of RTILs may be achieved. PMID:21337342

Mora-Pale, Mauricio; Meli, Luciana; Doherty, Thomas V; Linhardt, Robert J; Dordick, Jonathan S

2011-06-01

322

Biological Pretreatment of Lignocellulosic Substrates for Enhanced Delignification and Enzymatic Digestibility  

OpenAIRE

Sheer enormity of lignocellulosics makes them potential feedstock for biofuel production but, their conversion into fermentable sugars is a major hurdle. They have to be pretreated physically, chemically, or biologically to be used by fermenting organisms for production of ethanol. Each lignocellulosic substrate is a complex mix of cellulose, hemicellulose and lignin, bound in a matrix. While cellulose and hemicellulose yield fermentable sugars, lignin is the most recalcitrant polymer, consis...

Saritha, M.; Arora, Anju; Lata

2011-01-01

323

Pretreatment of Lignocellulosic Wastes to Improve Ethanol and Biogas Production: A Review  

OpenAIRE

Lignocelluloses are often a major or sometimes the sole components of different waste streams from various industries, forestry, agriculture and municipalities. Hydrolysis of these materials is the first step for either digestion to biogas (methane) or fermentation to ethanol. However, enzymatic hydrolysis of lignocelluloses with no pretreatment is usually not so effective because of high stability of the materials to enzymatic or bacterial attacks. The present work is dedicated to reviewing ...

Keikhosro Karimi; Taherzadeh, Mohammad J.

2008-01-01

324

Cellulose, hemicelluloses, lignin, and ash contents in various lignocellulosic crops for second generation bioethanol production  

OpenAIRE

Cellulose, hemicelluloses, lignin, and ash contents in various lignocellulosic crops for second generation bioethanol production. Various green energy crops are available for the production of renewable energy vectors such as second generation bioethanol. The efficiency of the energy recovery potential of these lignocellulosic crops depends on the crop husbandry, their content of main components (cellulose, hemicelluloses, lignin, ash) and on the second generation bioethanol production proces...

Godin, Bruno; Ghysel, Francois; Agneessens, Richard; Schmit, Thomas; Gofflot, Sebastien; Lamaudiere, Ste?phane; Sinnaeve, Georges; Goffart, Jean-pierre; Gerin, Patrick A.; Stilmant, Didier; Delcarte, Jerome

2010-01-01

325

Yield-determining factors in high-solids enzymatic hydrolysis of lignocellulose  

OpenAIRE

Abstract Background Working at high solids (substrate) concentrations is advantageous in enzymatic conversion of lignocellulosic biomass as it increases product concentrations and plant productivity while lowering energy and water input. However, for a number of lignocellulosic substrates it has been shown that at increasing substrate concentration, the corresponding yield decreases in a fashion which can not be explained by current models and knowledge of enzyme-substrate interactions. This ...

Felby Claus; Kristensen Jan B; Jørgensen Henning

2009-01-01

326

Design and construction of modular genetic devices and the enzymatic hydrolysis of lignocellulosic biomass  

OpenAIRE

The enzymatic deconstruction of lignocellulosic plant biomass is performed by specialist microbial species. It is a ubiquitous process within nature and central to the global recycling of carbon and energy. Lignocellulose is a complex heteropolymer, highly recalcitrant and resistant to hydrolysis due to the major polysaccharide cellulose existing as a crystalline lattice, intimately associated with a disordered sheath of hemicellulosic polysaccharides and lignin. In this thesis...

Barnard, Damian Kelly

2012-01-01

327

Spent fuel management in Japan  

International Nuclear Information System (INIS)

Japan has scarce energy resources and depends on foreign resources for 84% of its energy needs. Therefore, Japan has made efforts to utilize nuclear power as a key energy source since mid-1950's. Today, the nuclear energy produced from 49 nuclear power plants is responsible for about 31% of Japan's total electricity supply. The cumulative amount of spent fuel generated as of March 1995 was about 11,600 Mg U. Japan's policy of spent fuel management is to reprocess spent nuclear fuel and recycle recovered plutonium and uranium as nuclear fuel. The Tokai reprocessing plant continues stable operation keeping the annual treatment capacity or around 90 Mg U. A commercial reprocessing plant is under construction at Rokkasho, northern part of Japan. Although FBR is the principal reactor to use plutonium, LWR will be a major power source for some time and recycling of the fuel in LWRs will be prompted. (author). 3 figs

328

Management of HFIR spent fuel  

International Nuclear Information System (INIS)

The High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory (ORNL) has been unable to ship its spent fuel off-site for reprocessing since 1985. The HFIR storage pools are expected to fill up by the end of 1994. If a management alternative to existing HFIR pool storage is not identified and implemented by that time, the HFIR will be forced to shut down. This study identified and investigated five alternatives to managing the HFIR spent fuel, to determine the feasibility of implementing each in time to prevent shutdown of the HFIR: (1) increasing HFIR pool storage capacity, (2) storing the spent fuel at another ORNL pool, (3) storing the spent fuel in one or more hot cells at ORNL, (4) shipping the spent fuel off-site for reprocessing or storage elsewhere, and (5) installing a dedicated dry storage facility at ORNL. Of the alternatives investigated, only two could prevent the shutdown of the HFIR in the near term: increasing HFIR pool storage capacity or shipping the spent fuel off-site. Both options have been vigorously pursued because neither is assured of success, and at least one of the options must be successfully implemented if the HFIR is to continue operation. In addition, a third option was selected for implementation as an intermediate-term storage solution: installing a dedicated dry storage facility for the HFIR. An intermediate-term storage solution is needed because neither of the short-term solutions could ensure long-term continued operation ofld ensure long-term continued operation of the HFIR

329

Production of extensive chickpea (Cicer arietinum L.) protein hydrolysates with reduced antigenic activity.  

Science.gov (United States)

Chickpea protein isolate was used as starting material for the production of hypoallergenic protein hydrolysates. Western blotting of the protein isolate showed that IgE in sensitized patient sera strongly bound to the basic polypeptidic chains and recognized the acidic ones of 11S globulin. During the hydrolysis process by the individual and/or sequential action of endo- and exoproteases, a high reduction of antigenic activity was observed. Results suggest that the presence of intact or partially hydrolyzed basic polypeptide chains of 11S globulin are responsible for the formation of IgE complexes in protein hydrolysates obtained by exoprotease treatment; however, the digestion of these polypeptide chains by individual action of endoprotease caused a high loss of antigenic activity. The most effective reduction of antigenicity, >90%, was observed in extensive hydrolyzed chickpea proteins obtained by sequential treatment with endo- and exopeptidases. This chickpea protein hydrolysate could be useful for the elaboration of specialized hypoallergenic food products. PMID:10552721

Clemente, A; Vioque, J; Sanchez-Vioque, R; Pedroche, J; Millán, F

1999-09-01

330

Fermentation of sugars in orange peel hydrolysates to ethanol by recombinant Escherichia coli KO11  

Energy Technology Data Exchange (ETDEWEB)

The conversion of monosaccharides in orange peel hydrolysates to ethanol by recombinant Escherichia coli KO11 has been investigated in pH-controlled batch fermentations at 32 and 37{degrees}C. pH values and concentration of peel hydrolysate were varied to determine approximate optimal conditions and limitations of these fermentations. Very high yields of ethanol were achieved by this microorganism at reasonable ethanol concentrations (28-48 g/L). The pH range between 5.8 and 6.2 appears to be optimal. The microorganism can convert all major monosaccharides in orange peel hydrolysates to ethanol and to smaller amounts of acetic and lactic acids. Acetic acid is coproduced in equimolar amounts with ethanol by catabolism of salts of galacturonic acid.

Grohmann, K.; Cameron, R.G. [Citrus and Subtropical Products Lab., Winter Haven, FL (United States); Buslig, B.S. [Florida Department of Citrus, Winter Haven, FL (United States)

1995-12-31

331

Single cell protein production by penicillium expansum incorporating of acid hydrolysate of rice husk in medium  

International Nuclear Information System (INIS)

The aim of the research work is to bioconversion of rice husk to single cell protein by penicillium expansum. The rice husk was degraded chemically using sulphuric acid and perchloric acid with various concentrations (0.15, 0.30, 0.45, and 0.60 N) to fermentable sugars and these were used as substrate for the production of single cell protein by penicillium expansum. It was observed that the amount of single cell protein is higher in case of perchloric acid hydrolysate in comparison to sulphuric acid hydrolysate, while the protein content of single cell protein is higher in sulphuric acid hydrolysate. The single cell protein of penicillium expansum contains nearly all essential amino acids while it free from aflatoxin. (author)

332

In vitro bioactive properties of intact and enzymatically hydrolysed whey protein: targeting the enteroinsular axis.  

Science.gov (United States)

Enzymatically hydrolysed milk proteins have a variety of biofunctional effects some of which may be beneficial in the management of type 2 diabetes mellitus. The purpose of this study was to evaluate the effect of commercially available intact and hydrolysed whey protein ingredients (DH 32, DH 45) on markers of the enteroinsular axis (glucagon like peptide-1 secretion, dipeptidyl peptidase IV inhibition, insulin secretion and antioxidant activity) before and after simulated gastrointestinal digestion (SGID). A whey protein hydrolysate, DH32, significantly enhanced (P 0.05) or enhanced (DH 45, P < 0.05) following SGID. Intact whey stimulated GLP-1 secretion from enteroendocrine cells compared to vehicle control (P < 0.05). This data confirm that whey proteins and peptides can act through multiple targets within the enteroinsular axis and as such may have glucoregulatory potential. PMID:25666373

Power-Grant, O; Bruen, C; Brennan, L; Giblin, L; Jakeman, P; FitzGerald, R J

2015-03-11

333

Antioxidant activity of hydrolysates and peptide fractions derived from porcine hemoglobin.  

Science.gov (United States)

Porcine hemoglobin hydrolysate (PHH) was prepared with 6 different proteases (flavourzyme, papain, A.S.1398, alcalase, pepsin and trypsin). There was no correlation between extent of hydrolysis and antioxidant activity (p?>?0.05). The peptic hydrolysate prepared at 60 min possessed the strongest antioxidant potential (67.0?±?1.84%) among different hydrolysates, which was fractionated into 4 major types by ultrafiltration membranes with different molecular weight cut-off (MWCO), PHH-I (Mw?>?10 kDa), PHH-II (Mw?=?5-10 kDa), PHH-III (Mw?=?3-5 kDa) and PHH-IV (Mw? PHH-I > PHH-III > PHH-II. MW of the 2 major peptide fractions from PHH-IV was located at 2476 Da (F1) and 1042 Da (F2), respectively. PHH-IV could be utilized to develop physiologically functional foods or therapy drugs. PMID:23572716

Sun, Qian; Shen, Huixing; Luo, Yongkang

2011-02-01

334

Angiotensin converting enzyme (ACE) inhibitory, antihypertensive and antihyperlipidaemic activities of protein hydrolysates from Rhopilema esculentum.  

Science.gov (United States)

Angiotensin-converting enzyme (ACE) inhibitory, antihypertensive and antihyperlipidaemic activities of protein hydrolysates (RPH) from the jellyfish Rhopilema esculentum were investigated. R. esculentum was hydrolysed sequentially with pepsin and papain, and then the hydrolysate was ultrafiltered with a 2000 Da cut-off membrane. It was found that RPH contained high levels of Gly, Glu, Pro, Asp and Ala, having potential ACE inhibitory activity in vitro with an IC(50) of 1.28 mg/ml. It was also found that systolic blood pressure was reduced markedly in spontaneously hypertensive rats after single and chronic oral administration of RPH, indicating that RPH had an antihypertensive effect. In addition, oral administration of RPH decreased total serum cholesterol and triglyceride, and increased high-density lipoprotein cholesterol in rats fed with high-fat diet. These results indicate that RPH may prove to be a promising functional food for the prevention and treatment of hypertension and hyperlipidaemia. PMID:23442666

Liu, Xin; Zhang, Miansong; Zhang, Chao; Liu, Changheng

2012-10-15

335

Spent-fuel-storage alternatives  

Energy Technology Data Exchange (ETDEWEB)

The Spent Fuel Storage Alternatives meeting was a technical forum in which 37 experts from 12 states discussed storage alternatives that are available or are under development. The subject matter was divided into the following five areas: techniques for increasing fuel storage density; dry storage of spent fuel; fuel characterization and conditioning; fuel storage operating experience; and storage and transport economics. Nineteen of the 21 papers which were presented at this meeting are included in this Proceedings. These have been abstracted and indexed. (ATT)

1980-01-01

336

Spent graphite fuel element processing  

International Nuclear Information System (INIS)

The Department of Energy currently sponsors two programs to demonstrate the processing of spent graphite fuel elements. General Atomic in San Diego operates a cold pilot plant to demonstrate the processing of both US and German high-temperature reactor fuel. Exxon Nuclear Idaho Company is demonstrating the processing of spent graphite fuel elements from Rover reactors operated for the Nuclear Rocket Propulsion Program. This work is done at Idaho National Engineering Laboratory, where a hot facility is being constructed to complete processing of the Rover fuel. This paper focuses on the graphite combustion process common to both programs

337

Antioxidant and functional properties of collagen hydrolysates from Spanish mackerel skin as influenced by average molecular weight.  

Science.gov (United States)

In the current study, the relationships between functional properties and average molecular weight (AMW) of collagen hydrolysates from Spanish mackerel (Scomberomorous niphonius) skin were researched. Seven hydrolysate fractions (5.04 ? AMW ? 47.82 kDa) from collagen of Spanish mackerel skin were obtained through the processes of acid extraction, proteolysis, and fractionation using gel filtration chromatography. The physicochemical properties of the collagen hydrolysate fractions were studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), gel filtration chromatography, scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FTIR). The results indicated that there was an inverse relationship between the antioxidant activities and the logarithm of the AMW of the hydrolysate fractions in the tested AMW range. However, the reduction of AMW significantly enhanced the solubility of the hydrolysate fractions, and a similar AMW decrease of the hydrolysate fractions negatively affected the emulsifying and foaming capacities. This presented as a positive correlation between the logarithm of AMW and emulsion stability index, emulsifying activity index, foam stability, and foam capacity. Therefore, these collagen hydrolysates with excellent antioxidant activities or good functionalities as emulsifiers could be obtained by controlling the effect of the digestion process on the AMW of the resultant hydrolysates. PMID:25090114

Chi, Chang-Feng; Cao, Zi-Hao; Wang, Bin; Hu, Fa-Yuan; Li, Zhong-Rui; Zhang, Bin

2014-01-01

338

Antioxidant Potential of Date (Phoenix dactylifera L.) Seed Protein Hydrolysates and Carnosine in Food and Biological Systems.  

Science.gov (United States)

Date seed protein hydrolysates were evaluated for antioxidant activity as well as solubility and water-holding capacity in food and biological model systems. Date seed protein hydrolysates as well as carnosine exhibited >80% of solubility over a pH range of 2-12. The hydrolysates and carnosine at 0.5% (w/w) were also found to be effective in enhancing water-holding capacity and cooking yield in a fish model system, which was nearly similar to sodium tripolyphosphate (STPP; 0.3%, w/w). Incorporation of hydrolysates (200 ppm) in fish model systems resulted in the highest inhibition (30%) of oxidation in comparison to butylated hydroxytoluene (BHT; 9%). In addition, hydrolysates and carnosine inhibited ?-carotene oxidation by 75%. The hydrolysates (0.1 mg/mL) inhibited LDL cholesterol oxidation by 60%, whereas carnosine inhibited oxidation by 80% after 12 h of incubation. Additionally, hydrolysates and carnosine effectively inhibited hydroxyl (6 mg/mL) and peroxyl (0.1 mg/mL) radical-induced DNA scission. Therefore, date seed protein hydrolysates could be used as a potential functional food ingredient for health promotion. PMID:25553507

Ambigaipalan, Priyatharini; Shahidi, Fereidoon

2015-01-28

339

Antioxidant and Functional Properties of Collagen Hydrolysates from Spanish Mackerel Skin as Influenced by Average Molecular Weight  

Directory of Open Access Journals (Sweden)

Full Text Available In the current study, the relationships between functional properties and average molecular weight (AMW of collagen hydrolysates from Spanish mackerel (Scomberomorous niphonius skin were researched. Seven hydrolysate fractions (5.04 ? AMW ? 47.82 kDa from collagen of Spanish mackerel skin were obtained through the processes of acid extraction, proteolysis, and fractionation using gel filtration chromatography. The physicochemical properties of the collagen hydrolysate fractions were studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE, gel filtration chromatography, scanning electron microscope (SEM and Fourier transform infrared spectroscopy (FTIR. The results indicated that there was an inverse relationship between the antioxidant activities and the logarithm of the AMW of the hydrolysate fractions in the tested AMW range. However, the reduction of AMW significantly enhanced the solubility of the hydrolysate fractions, and a similar AMW decrease of the hydrolysate fractions negatively affected the emulsifying and foaming capacities. This presented as a positive correlation between the logarithm of AMW and emulsion stability index, emulsifying activity index, foam stability, and foam capacity. Therefore, these collagen hydrolysates with excellent antioxidant activities or good functionalities as emulsifiers could be obtained by controlling the effect of the digestion process on the AMW of the resultant hydrolysates.

Chang-Feng Chi

2014-07-01

340

Antioxidant Activity of Fish Protein Hydrolysates in in vitro Assays and in Oil-in-Water Emulsions.  

DEFF Research Database (Denmark)

The aim of this study was to screen different protein hydrolysates with respect to their antioxidative properties in order to select the most promising extracts for further evaluation in oil-in-water emulsions. Three fractions of protein hydrolysates (Crude, >5kDa and 5kDa, 3-5kDa and

Farvin, Sabeena; Andersen, Lisa Lystbæk

341

Percutaneous removal of pulmonary artery emboli with hydrolyser catheter in pigs  

Energy Technology Data Exchange (ETDEWEB)

To evaluate the efficacy and safety of the Hydrolyser catheter for per,cutaneous treatment of massive pulmonary embolism in pigs. Twelve pigs, each weighing between 55 kg and 89 kg, were used. Radio-opaque 9 cm x 0.8 cm and 4.5 cm x 0.8 cm clots, produced by mixing pig blood with iodinated contrast agent in vacutainers, were injected via the jugular vein until central pulmonary embolism (main and proximal lobar arteries) was obtained with significant systemic and pulmonary hemodynamic modifications. From a femoral approach, the 7-French Hydrolyser thrombectomy catheter was run over a 0.025-inch (0.64-mm) guide wire to remove the pulmonary emboli. Hemodynamic, gasometric and angiographic monitoring was performed before and after treatment. The procedure's safety and completeness of emboli removal was assessed by cardiopulmonary autopsy. Three of the 12 pigs died during embolization. Thrombectomy was therefore performed in 9, and central emboli could be obtained in 7 of the 9. The Hydrolyser could be manipulated only in central pulmonary arteries and could aspirate only central emboli in 5 of the 7 pigs that had them. Despite minimal angiographic improvement seen in these 5, there was no significant hemodynamic and gasometric improvement after treatment. The procedure induced an increase in free hemoglobin blood levels. Autopsies revealed an average of 2 endothelial injuries per pig (mainly adherent endocardial thrombi) in both nontreated (n = 3) and Hydrolyser-treated (n = 9) groups. The Hydrolyser thrombectomy catheter can be promptly positioned and easily steered in central pulmonary arteries. It can be used to partially remove central emboli, but not peripheral pulmonary emboli. Most of the injuries observed may not have been strictly related to Hydrolyser use. The pig might not be a suitable animal model for treatment of massive pulmonary embolism. (author)

Lacoursiere, L. [Hopital Laval, Dept. d' Imagerie Medicale, Ste-Foy, Quebec (Canada); Millward, S. [University of Ottawa, Ottawa Hospital, Civic Campus, Dept. of Diagnostic Imaging, Ottawa, Ontario (Canada); Veinot, J.P. [University of Ottawa, Ottawa Hospital, Civic Campus, Dept. of Pathology and Laboratory Medicine, Ottawa, Ontario (Canada); Labinaz, M. [University of Ottawa, Ottawa Hospital, Civic Campus, Dept. of Cardiology and Medicine, Ottawa, Ontario (Canada)

2001-04-01

342

The protein encoded by the rolB plant oncogene hydrolyses indole glucosides.  

OpenAIRE

The rolB gene of Agrobacterium rhizogenes, whose expression stimulates the formation of roots by transformed plant tissues and other growth alterations in transgenic plants, codes for a beta-glucosidase able to hydrolyse indole-beta-glucosides. Indeed, we show that extracts of bacteria and/or plant tissue expressing the rolB protein hydrolyse indoxyl-beta-glucoside (plant indican). Because of the structural similarity between indoxyl-beta-glucoside and indole-3-acetyl-beta-glucoside (IAA-beta...

Estruch, J. J.; Schell, J.; Spena, A.

1991-01-01

343

Improvement of biotechnological xylitol production by glucose during cultive of Candida guilliermondii in sugarcane bagasse hydrolysate  

OpenAIRE

The effect of glucose on xylose-to-xylitol bioconversion by Candida guilliermondii was examined by adding it to sugarcane bagasse hydrolysate medium to obtain different glucose:xylose ratios (1:25, 1:12, 1:5 and 1:2.5). Under experimental conditions, increasing glucose:xylose ratio improved the assimilation of the xylose present in the hydrolysate by yeast, resulting in biomass increase, and in the formation of xylitol and glycerol/ethanol by-products. Maximum values of xylitol yield (0.59 g ...

Débora Danielle Virgínio da Silva; Ismael Maciel de Mancilha; Silvio Silvério da Silva; Maria das Graças de Almeida Felipe

2007-01-01

344

Antioxidant Activity of Hydrolysates Prepared from Flaxseed Cake Proteins Using Pancreatin  

Directory of Open Access Journals (Sweden)

Full Text Available Proteins were isolated from defatted flaxseed cake and hydrolysed with pancreatin. The hydrolysis process was conducted at a stable temperature of 50°C and pH 7.5, and monitored with the pH-stat method. The obtained hydrolysates with a degree of hydrolysis (DH of 5, 10, 15, 20, 25% were investigated in terms of antioxidant properties. The radical scavenging activity was assayed against DPPH· and ABTS·+, the reducing ability - with FRAP assay, and the capability to bind Fe(II - by reaction with ferrozine. SE-HPLC analysis was used to determine molecular weight distribution of hydrolysis products.

Karama? Magdalena

2014-12-01

345

Effects of Some Environmental Factors on Growth Characteristics of Candida utilis on Peat Hydrolysates  

OpenAIRE

Samples of peat from Pine Island and Brookston bogs in Minnesota were hydrolyzed with various concentrations of HCl or H2SO4 solutions, before or after debituminization (an extraction process used to remove waxy materials, bitumens, from peat), to produce peak hydrolysates as growth substrates for Candida utilis. Hydrolysates were neutralized with concentrated NaOH solution to pH 3.5, 4.5, 5.0, 5.5, 6.0, and 7.0. The precipitated humates were removed by filtration. The resulting peat hydrolys...

Chang, Fu-hsian

1985-01-01

346

Information on spent fuel transport  

International Nuclear Information System (INIS)

In Germany, the legal basis for management of spent fuel from nuclear power plants is a resolution of 28 September 19979 of the heads of governments of the Laender (federal states) and the Federal Chancellor. It is provided by this resolution that any nuclear power plant in Germany has to set up and present to the supervisory bodies a spent fuel management plan for six years in advance, giving proof that adequate provisions are taken for safe management of spent fuel elements arising from power plant operation, ensuring safe interim storage and disposal of the spent fuel elements and radioactive material in a final waste disposal facility (radwaste management plan). The necessary transports are carried out on behalf of the electric power industry. On 30 April 1998, the Federal Ministry of the Environment, Nature Conservation and Reactor Safety (BMU) announced that during the last two years, the usual external radioactivity scans of incoming transports at the radwaste reprocessing facility of the Cogema company at La Hague detected at some locations on the loading space of the railway freight cars carrying the German transport casks radioactive contamination exceeding the maximum permissible contamination laid down in the transport regulations. In response to this information, a representative of the electric power industry, the vicepresident engineering of the Bayernwerk utility, Dr.-Ing. Eberhard Wild, presented a statement to the press which is reproduced in this aro the press which is reproduced in this article. (orig./CB)

347

Spent fuel carrier ''Hinoura Maru''  

International Nuclear Information System (INIS)

With the development of nuclear power in Japan, the amount of spent fuel has increased gradually, and its reprocessing has become a serious problem. This led to the construction of the first reprocessing plant in Tokai Village, Ibaraki Prefecture. The method to transport spent fuel safely and economically was studied, and it was decided to transport it by sea from various power stations mostly located in coastal areas to the exclusive port for the Tokai Plant, then by land transport from the port to the reprocessing plant about 4 km distant. Ship Inspection Regulation No. 610 was established by the Ministry of Transport in 1974, and the spent fuel carrier ''HINOURA MARU'' was designed and rebuilt on the basis of this regulation. The collision-enduring hull structure, the water depth and size of the ports concerned, the number of casks, the operation cost and others were investigated thoroughly. The main particulars of the ship are as follows: gross tonnage 1290 t, length overall 77.55 m, full load draft 4.20 m, service speed 11 knots, propulsive power 2500 PS, the number of casks loaded 4, and complement 20. The features of this ship are the collision and stranding-enduring structures, stability characteristic, radiation shield structure, hold-cooling equipment, cask-fixing equipment, hold bilge tanks, and water pouring equipment for holds. The management of spent fuel transport is explained. (Kako, I.)

348

Reprocessing spent fuel in France  

International Nuclear Information System (INIS)

A review is given of the reprocessing of spent fuel in France. The organization for dealing with waste is outlined. A description is given of research and development work into the Purex process. The processing of the wastes and effluents arising is also discussed. (U.K.)

349

Characterization of the Immunogenicity and Allergenicity of Two Cow's Milk Hydrolysates – A Study in Brown Norway Rats  

DEFF Research Database (Denmark)

Hypoallergenic infant formulas based on hydrolysed milk proteins are used in the diet for cow's milk allergic infants. For a preclinical evaluation of the immunogenicity and allergenicity of new protein ingredients for such hypoallergenic infant formulas as well as for the investigation of which characteristics of hydrolysates that contribute to allergenicity, in vivo models are valuable tools. In this study, we examine the immunogenicity and allergenicity of two hydrolysates in a Brown Norway (BN) rat model, using i.p. dosing, which allows for the use of small quantities. Intact BLG, hydrolysed BLG and a hydrolysed whey product suitable for use in extensively hydrolysed formulas were thoroughly characterized for protein chemical features and administered to BN rats by i.p. immunization with or without adjuvant. Sera were analysed for specific IgG and IgE for evaluation of sensitizing capacity, immunogenicity and antibody?binding capacity. For evaluation of eliciting capacity a skin test was performed. The study showed that the hydrolysates had no residual allergenicity, lacking the capacity to sensitize and elicit reactions in the BN rats. Dosing with or without adjuvant induced a large difference in immunogenicity. Only antibodies from rats sensitized to intact BLG with adjuvant were able to bind the hydrolysates, and the whey?based hydrolysate only showed immunogenicity when dosed with adjuvant. This study showed that hydrolysates can be evaluated by an i.p. animal model, but that the choice of in vitro tests used for evaluation of antibody responses may greatly influence the result as well as may the use of adjuvant.

BØgh, Katrine Lindholm; Barkholt, Vibeke

2015-01-01

350

Spent fuel transports: Anger about Castors  

International Nuclear Information System (INIS)

New spent fuel casks should avoid the shutdown of nuclear power plants. Since the scandal about increased radioactivity when handling spent fuel pins they are stored near by the reactors. A factory at Krefeld has developed safer Castors

351

Cotter's new plant diets on spent catalysts  

International Nuclear Information System (INIS)

Cotter Corp.'s new 60-tpd spent-catalyst processing plant that recovers molybdenum, nickel, tungsten and vanadium products from spent catalysts is described. The company entered the business as a sideline to its main activity--the mining and processing of uranium ore. The spent-catalyst plant contains ammonium carbonate and sodium hydroxide leach circuits to provide the versatility required to recover various metals from a variety of spent catalysts

352

Spent fuel storage process equipment development  

International Nuclear Information System (INIS)

Nuclear energy which is a major energy source of national energy supply entails spent fuels. Spent fuels which are high level radioactive meterials, are tricky to manage and need high technology. The objectives of this study are to establish and develop key elements of spent fuel management technologies: handling equipment and maintenance, process automation technology, colling system, and cleanup system. (author)

353

Development of process variants for fast pyrolysis of lignocellulose in a double-lead screw reactor; Entwicklung von Verfahrensvarianten zur Schnellpyrolyse von Lignocellulose im Doppelschneckenreaktor  

Energy Technology Data Exchange (ETDEWEB)

Karlsruhe Research Center (FZK) is working on a two-stage concept for synfuel production from lignocellulose. The contribution describes the process, including properties of and requirements on educts, products, and working fluids. The development of process variants is discussed on the basis of experimental results. (orig.)

Kornmayer, C.; Dinjus, E.; Henrich, E.; Weirich, F. [Forschungszentrum Karlsruhe (Germany); Reimert, R. [Engler-Bunte-Inst., Univ. Karlsruhe (Germany)

2006-07-01

354

Oberflächenchemie und Kinetik der Hydrolyse von Isocyansäure auf TiO2 Anatas  

OpenAIRE

Die selektive katalytische Reduktion (SCR) von Stickoxiden mit Ammoniak oder Harnstoff als Reduktionsmittel stellt die aussichtsreichste Technologie für die Abgasnachbehandlung bei Nutzfahrzeugen dar. Die Erzeugung des Ammoniaks erfolgt durch die katalytische hydrolytische Zersetzung des an Bord mitgeführten Harnstoffs. In der vorliegenden Arbeit wurden die Einzelschritte der Hydrolyse des wichtigsten Zwischenprodukts, der Isocyansäure, über einem TiO2 Anatas Katalysator untersucht. Die r...

Hauck, Philipp Christian Dino Patrick

2007-01-01

355

A paper chromatographic technique for quantitative evaluation of hydrolysed and ionic components in 201Tl radiopharmaceuticals  

International Nuclear Information System (INIS)

A reported paper chromatographic technique has been extended to delineate the hydrolysed components in 201Tl radiopharmaceuticals for the determination of radiochemical purity. Detailed radiochemical purity analysis of 201TlCl has been demonstrated using mini paper chromatographic systems. The technique is also useful in evaluation of the radiochemical purity of 67Ga and 111In radiopharmaceuticals

356

Enzymatic hydrolysis of rice protein with papain and antioxidation activity of hydrolysate  

Science.gov (United States)

The enzymatic hydrolysis technology of rice protein and the antioxidant activity of the hydrolysate were studied. Substrate concentration,enzyme dose,pH value and temperature were selected as factors to optimize the hydrolysis parameters with single—factor and orthogonal tests. Results show the opti...

357

Nitrogen absorption in pancreatectomized patients: protein versus protein hydrolysate as substrate.  

Science.gov (United States)

To investigate nitrogen absorption in the absence of the pancreas, six patients with total pancreatectomy, all in stable nutritional and metabolic condition, underwent two periods of enteral nutrition identical in all respects except for the nitrogen source. Nitrogen source was either lactalbumin or its hydrolysate. The quantity and quality of calories infused simulated the patient's usual diet, which was a high-protein diet (2.0 +/- 0.4 gm/kg body weight). Pancreatic enzyme replacement therapy was discontinued during each period of enteral nutrition. All patients had greater nitrogen absorption during the enteral nutrition with lactalbumin hydrolysate than that with lactalbumin (91% +/- 2% vs 61% +/- 6% of nitrogen intake, p less than 0.02). Despite this difference in absorption, nitrogen balances during the two periods of enteral nutrition were not significantly different. This appeared to be caused by a urea production rate that was greater during the enteral nutrition with lactalbumin hydrolysate than the rate during that with lactalbumin (26 +/- 1 gm/24 hr vs 16 +/- 3 gm/24 hr, p less than 0.05). Plasma concentrations of amino acids and proteins did not differ significantly during the two treatments. In conclusion, the data suggest that (1) the intestine plays a significant role in protein digestion and that (2) enteral feeding with a protein hydrolysate could eliminate the need for a high-protein diet in patients with pancreatic insufficiency. PMID:2492590

Steinhardt, H J; Wolf, A; Jakober, B; Schmuelling, R M; Langer, K; Brandl, M; Fekl, W; Adibi, S A

1989-02-01

358

Fractionation of protein hydrolysates of fish and chicken using membrane ultrafiltration: investigation of antioxidant activity.  

Science.gov (United States)

In this work, chicken and fish peptides were obtained using the proteolytic enzymes ?-Chymotrypsin and Flavourzyme. The muscle was hydrolyzed for 4 h, and the resulting peptides were evaluated. Hydrolysates were produced from Argentine croaker (Umbrina canosai) with a degree of hydrolysis (DH) of 25.9 and 27.6% and from chicken (Gallus domesticus) with DH of 17.8 and 20.6% for Flavourzyme and ?-Chymotrypsin, respectively. Membrane ultrafiltration was used to separate fish and chicken hydrolysates from Flavourzyme and ?-Chymotrypsin based on molecular weight cutoff of >1,000, 500, and <500 Da, to produce fractions (F1,000, F1,000-500, and F500) with antioxidant activity. Fish hydrolysates produced with Flavourzyme (FHF) and ?-Chymotrypsin showed 60.8 and 50.9% of peptides with a molecular weight of <3 kDa in its composition, respectively. To chicken hydrolysates produced with Flavourzyme and ?-Chymotrypsin (CHC) was observed 83 and 92.4% of peptides with a molecular weight of <3 kDa. The fraction that showed, in general, higher antioxidant potential was F1,000 from FHF. When added 40 mg/mL of FHF and CHC, 93 and 80% of lipid oxidation in ground beef homogenates was inhibited, respectively. The composition of amino acids indicated higher amino acids hydrophobic content and amino acids containing sulfuric residues for FHF, which showed antioxidant potential. PMID:24449375

Centenaro, Graciela Salete; Salas-Mellado, Myriam; Pires, Carla; Batista, Irineu; Nunes, Maria L; Prentice, Carlos

2014-03-01

359

Influence of peptides-phenolics interaction on the antioxidant profile of protein hydrolysates from Brassica napus.  

Science.gov (United States)

The role of the peptides-phenolic compounds (PC) interaction on the antioxidant capacity profile (ACP) of protein hydrolysates from rapeseed (Brassica napus) was studied in 36 hydrolysates obtained from a PC-rich and PC-reduced protein substrate. The latent profile analysis (LPA), with data of seven in vitro methods and one assay for cellular antioxidant activity (CAA), allowed identifying five distinctive groups of hydrolysates, each one with distinctive ACP. The interaction of peptides with naturally present PC diminished in vitro antioxidant activity in comparison with their PC-reduced counterparts. However, CAA increased when peptides-PC interaction occurred. The profile with the highest average CAA (62.41 ± 1.48%), shown by hydrolysates obtained by using alcalase, shared typical values of Cu(2+)-catalysed ?-carotene oxidation (62.41 ± 0.43%), ?-carotene bleaching inhibition (91.75 ± 0.22%) and Cu(2+)-chelating activity (74.53 ± 0.58%). The possibilities for a sample to exhibit ACP with higher CAA increased with each unit of positively charged amino acids, according to multinomial logistic regression analysis. PMID:25704722

Hernández-Jabalera, Anaid; Cortés-Giraldo, Isabel; Dávila-Ortíz, Gloria; Vioque, Javier; Alaiz, Manuel; Girón-Calle, Julio; Megías, Cristina; Jiménez-Martínez, Cristian

2015-07-01

360

Soybean and casein hydrolysates induce grapevine immune responses and resistance against Plasmopara viticola.  

Science.gov (United States)

Plasmopara viticola, the causal agent of grapevine downy mildew, is one of the most devastating grape pathogen in Europe and North America. Although phytochemicals are used to control pathogen infections, the appearance of resistant strains and the concern for possible adverse effects on environment and human health are increasing the search for alternative strategies. In the present investigation, we successfully tested two protein hydrolysates from soybean (soy) and casein (cas) to trigger grapevine resistance against P. viticola. On Vitis vinifera cv. Marselan plants, the application of soy and cas reduced the infected leaf surface by 76 and 63%, as compared to the control, respectively. Since both hydrolysates might trigger the plant immunity, we investigated their ability to elicit grapevine defense responses. On grapevine cell suspensions, a different free cytosolic calcium signature was recorded for each hydrolysate, whereas a similar transient phosphorylation of two MAP kinases of 45 and 49 kDa was observed. These signaling events were followed by transcriptome reprogramming, including the up-regulation of defense genes encoding pathogenesis-related (PR) proteins and the stilbene synthase enzyme responsible for the biosynthesis of resveratrol, the main grapevine phytoalexin. Liquid chromatography analyses confirmed the production of resveratrol and its dimer metabolites, ?- and ?-viniferins. Overall, soy effects were more pronounced as compared to the cas ones. Both hydrolysates proved to act as elicitors to enhance grapevine immunity against pathogen attack. PMID:25566290

Lachhab, Nihed; Sanzani, Simona M; Adrian, Marielle; Chiltz, Annick; Balacey, Suzanne; Boselli, Maurizio; Ippolito, Antonio; Poinssot, Benoit

2014-01-01

361

Production and functional characterisation of antioxidative hydrolysates from corn protein via enzymatic hydrolysis and ultrafiltration.  

Science.gov (United States)

Corn protein was hydrolysed by three microbial proteases and further separated by sequential ultra-filtration to 12 hydrolysate fractions which were investigated for free radical scavenging capacity and chelating activity. The oxygen radical absorbance capacity (ORAC) of the hydrolysates varied significantly between 65.6 and 191.4?moles Trolox equivalents (TE)/g dried weight with a small peptide fraction (NP-F3) produced by neutral protease (NP) possessing the highest antioxidant activity. The 1,1-diphenyl-2-picrylhydrazyl radical (DPPH()) scavenging activities of the hydrolysate fractions also varied significantly between 18.4 and 38.7?moles TE/g. Two fractions (AP-F2 and AP-F3) produced by alkaline protease (AP) showed the strongest activity. However, no significant difference was detected on the chelating activity of the fractions. NP-F3, AP-F2, and AP-F3 were incorporated into ground beef to determine their effects on lipid oxidation during 15-day storage period. NP-F3 was the only fraction that inhibited lipid oxidation at both 250 and 500?g/g levels by as much as 52.9%. PMID:22953842

Zhou, Kequan; Sun, Shi; Canning, Corene

2012-12-01

362

Preparation of antioxidant enzymatic hydrolysates from honeybee-collected pollen using plant enzymes.  

Science.gov (United States)

Enzymatic hydrolysates of honeybee-collected pollen were prepared using food-grade proteinase and aminopeptidases entirely of plant origin. Bromelain from pineapple stem was applied (8?mAU/g substrate) in the first hydrolysis stage. Aminopeptidase (0.05?U/g substrate) and proline iminopeptidase (0.03?U/g substrate) from cabbage leaves (Brassica oleracea var. capitata), and aminopeptidase (0.2?U/g substrate) from chick-pea cotyledons (Cicer arietinum L.) were involved in the additional hydrolysis of the peptide mixtures. The degree of hydrolysis (DH), total phenolic contents, and protein contents of these hydrolysates were as follows: DH (about 20-28%), total phenolics (15.3-27.2??g/mg sample powder), and proteins (162.7-242.8??g/mg sample powder), respectively. The hydrolysates possessed high antiradical scavenging activity determined with DPPH (42-46% inhibition). The prepared hydrolysates of bee-collected flower pollen may be regarded as effective natural and functional dietary food supplements due to their remarkable content of polyphenol substances and significant radical-scavenging capacity with special regard to their nutritional-physiological implications. PMID:21318132

Marinova, Margarita D; Tchorbanov, Bozhidar P

2011-01-01

363

Draft Genome Sequence of Kluyveromyces marxianus Strain DMB1, Isolated from Sugarcane Bagasse Hydrolysate  

OpenAIRE

We determined the genome sequence of a thermotolerant yeast, Kluyveromyces marxianus strain DMB1, isolated from sugarcane bagasse hydrolysate, and the sequence provides further insights into the genomic differences between this strain and other reported K. marxianus strains. The genome described here is composed of 11,165,408 bases and has 4,943 protein-coding genes.

Suzuki, Toshihiro; Hoshino, Tamotsu; Matsushika, Akinori

2014-01-01

364

Draft Genome Sequence of Kluyveromyces marxianus Strain DMB1, Isolated from Sugarcane Bagasse Hydrolysate.  

Science.gov (United States)

We determined the genome sequence of a thermotolerant yeast, Kluyveromyces marxianus strain DMB1, isolated from sugarcane bagasse hydrolysate, and the sequence provides further insights into the genomic differences between this strain and other reported K. marxianus strains. The genome described here is composed of 11,165,408 bases and has 4,943 protein-coding genes. PMID:25059876

Suzuki, Toshihiro; Hoshino, Tamotsu; Matsushika, Akinori

2014-01-01

365

The extraction kinetics of calcium ions at hydrolyses of proto-pectin of sunflower heads  

International Nuclear Information System (INIS)

The purpose of present work is studying of extraction kinetics of calcium ions at acid hydrolyses of proto-pectin of sunflower heads. Obtained experimental data in this article shows important role of calcium ions in stabilization of various component structures of proto-pectin hydrolysis and possibility of process regulation by selective removal of calcium ions

366

Distribution of calcium ions in hydrolyses products of proto-pectin of sunflower head  

International Nuclear Information System (INIS)

The purpose of present work is determination calcium ions containing in hydrolyses products of proto-pectins of sunflowers heads which let elaborate optimal method of high quality pectin obtaining. Obtained data in this article indicate that at least one of chemical reactions at hydrolysis passes with participations calcium ions

367

Bactericidal effect of hydrolysable and condensed tannin extracts on Campylobacter jejuni in vitro.  

Science.gov (United States)

Strategies are sought to reduce intestinal colonisation of food-producing animals by Campylobacter jejuni, a leading bacterial cause of human foodborne illness worldwide. Presently, we tested the antimicrobial activity of hydrolysable-rich blackberry, cranberry and chestnut tannin extracts and condensed tannin-rich mimosa, quebracho and sorghum tannins (each at 100 mg/mL) against C. jejuni via disc diffusion assay in the presence of supplemental casamino acids. We found that when compared to non-tannin-treated controls, all tested tannins inhibited the growth of C. jejuni and that inhibition by the condensed tannin-rich mimosa and quebracho extracts was mitigated in nutrient-limited medium supplemented with casamino acids. When tested in broth culture, both chestnut and mimosa extracts inhibited growth of C. jejuni and this inhibition was much greater in nutrient-limited than in full-strength medium. Consistent with observations from the disc diffusion assay, the inhibitory activity of the condensed tannin-rich mimosa extracts but not the hydrolysable tannin-rich chestnut extracts was mitigated by casamino acid supplementation to the nutrient-limited medium, likely because the added amino acids saturated the binding potential of the condensed tannins. These results demonstrate the antimicrobial activity of various hydrolysable and condensed tannin-rich extracts against C. jejuni and reveal that condensed tannins may be less efficient than hydrolysable tannins in controlling C. jejuni in gut environments containing high concentrations of amino acids and soluble proteins. PMID:22528299

Anderson, Robin C; Vodovnik, Maša; Min, Byeng R; Pinchak, William E; Krueger, Nathan A; Harvey, Roger B; Nisbet, David J

2012-07-01

368

Soybean and casein hydrolysates induce grapevine immune responses and resistance against Plasmopara viticola  

Science.gov (United States)

Plasmopara viticola, the causal agent of grapevine downy mildew, is one of the most devastating grape pathogen in Europe and North America. Although phytochemicals are used to control pathogen infections, the appearance of resistant strains and the concern for possible adverse effects on environment and human health are increasing the search for alternative strategies. In the present investigation, we successfully tested two protein hydrolysates from soybean (soy) and casein (cas) to trigger grapevine resistance against P. viticola. On Vitis vinifera cv. Marselan plants, the application of soy and cas reduced the infected leaf surface by 76 and 63%, as compared to the control, respectively. Since both hydrolysates might trigger the plant immunity, we investigated their ability to elicit grapevine defense responses. On grapevine cell suspensions, a different free cytosolic calcium signature was recorded for each hydrolysate, whereas a similar transient phosphorylation of two MAP kinases of 45 and 49 kDa was observed. These signaling events were followed by transcriptome reprogramming, including the up-regulation of defense genes encoding pathogenesis-related (PR) proteins and the stilbene synthase enzyme responsible for the biosynthesis of resveratrol, the main grapevine phytoalexin. Liquid chromatography analyses confirmed the production of resveratrol and its dimer metabolites, ?- and ?-viniferins. Overall, soy effects were more pronounced as compared to the cas ones. Both hydrolysates proved to act as elicitors to enhance grapevine immunity against pathogen attack. PMID:25566290

Lachhab, Nihed; Sanzani, Simona M.; Adrian, Marielle; Chiltz, Annick; Balacey, Suzanne; Boselli, Maurizio; Ippolito, Antonio; Poinssot, Benoit

2014-01-01

369

Protein Hydrolysates from Non-bovine and Plant Sources Replaces Tryptone in Microbiological Media  

Science.gov (United States)

Tryptone (pancreatic digest of casein) is a common ingredient in laboratory and fermentation media for growing wild-type and genetically modified microorganisms. Many of the commercially manufactured products such as human growth hormone, antibiotics, insulin, etc. are produced by recombinant strains grown on materials derived from bovine sources. With the emergence of Bovine Spongiform Encephalopathy (BSE) and the consequent increase in Food and Drug Administration (FDA) regulations, elimination of materials of bovine origin from fermentation media is of paramount importance. To achieve this objective, a number of protein hydrolysates derived from non-bovine animal and plant sources were evaluated. Tryptone in Luria-Bertani (LB) broth was replaced with an equal quantity of alternate protein hydrolysates. Four of the six hydrolysates (one animal and three from plants) were found to efficiently replace the tryptone present in LB-medium as measured by growth rate and growth yield of a recombinant Escherichia coli strain. In addition, we have determined plasmid stability, inducibility and activity of the plasmid encoded ?-galactosidase in the recombinant strain grown in the presence of various protein hydrolysates.

Ranganathan, Yamini; Patel, Shifa; Pasupuleti, Vijai K.; Meganathan, R.

370

Purification and characterization of antioxidative peptides from round scad (Decapterus maruadsi) muscle protein hydrolysate.  

Science.gov (United States)

Muscle protein from round scad (Decapterus maruadsi) was hydrolyzed with five commercial proteases, namely, Alcalase, neutral protease, papain, pepsin, and trypsin. Round scad hydrolysate (RSH) prepared with Alcalase demonstrated high antioxidative activity. After ultrafiltration, RSH-III fraction (MWscad muscle protein can be developed into antioxidative ingredients in functional foods. PMID:24518328

Jiang, Haiping; Tong, Tianzhe; Sun, Jianhua; Xu, Yuanjin; Zhao, Zhongxing; Liao, Dankui

2014-07-01

371

Xylose utilizing zymomonas mobilis with improved ethanol production in biomass hydrolysate medium  

Energy Technology Data Exchange (ETDEWEB)

Xylose-utilizing, ethanol producing strains of Zymomonas mobilis with improved performance in medium comprising biomass hydrolysate were isolated using an adaptation process. Independently isolated strains were found to have independent mutations in the same coding region. Mutation in this coding may be engineered to confer the improved phenotype.

Caimi, Perry G; Hitz, William D; Stieglitz, Barry; Viitanen, Paul V

2013-07-02

372

Xylose utilizing Zymomonas mobilis with improved ethanol production in biomass hydrolysate medium  

Science.gov (United States)

Xylose-utilizing, ethanol producing strains of Zymomonas mobilis with improved performance in medium comprising biomass hydrolysate were isolated using an adaptation process. Independently isolated strains were found to have independent mutations in the same coding region. Mutation in this coding may be engineered to confer the improved phenotype.

Caimi, Perry G; Hitz, William D; Viitanen, Paul V; Stieglitz, Barry

2013-10-29

373

Environmental impacts of a lignocellulose feedstock biorefinery system: An assessment  

International Nuclear Information System (INIS)

Biomass is a sustainable alternative to fossil energy carriers which are used to produce fuels, electricity, chemicals, and other goods. At the moment, the main biobased products are obtained by the conversion of biomass to basic products like starch, oil, and cellulose. In addition, some single chemicals and fuels are produced. Presently, concepts of biorefineries which will produce a multitude of biomass-derived products are discussed. Biorefineries are supposed to contribute to a more sustainable resource supply and to a reduction in greenhouse gas emissions. However, biobased products and fuels may also be associated with environmental disadvantages due to, e.g. land use or eutrophication of water. We performed a Life Cycle Assessment of a lignocellulose feedstock biorefinery system and compared it to conventional product alternatives. The biorefinery was found to have the greatest environmental impacts in the three categories: fossil fuel use, respiratory effects, and carcinogenics. The environmental impacts predominantly result from the provision of hydrochloric acid and to a smaller extent also from the provision of process heat. As the final configuration of the biorefinery cannot be determined yet, various variants of the biorefinery system were analysed. The optimum variant (acid and heat recoveries) yields better results than the fossil alternatives, with the total environmental impacts being approx. 41% lower than those of the fossil counterparts. For most biorefinery variants analysed, the environmental performance in some impact categories is better than that of the fossil counterparts while disadvantages can be seen in other categories.

374

Using Populus as a lignocellulosic feedstock for bioethanol.  

Science.gov (United States)

Populus species along with species from the sister genus Salix will provide valuable feedstock resources for advanced second-generation biofuels. Their inherent fast growth characteristics can particularly be exploited for short rotation management, a time and energy saving cultivation alternative for lignocellulosic feedstock supply. Salicaceae possess inherent cell wall characteristics with favorable cellulose to lignin ratios for utilization as bioethanol crop. We review economically important traits relevant for intensively managed biofuel crop plantations, genomic and phenotypic resources available for Populus, breeding strategies for forest trees dedicated to bioenergy provision, and bioprocesses and downstream applications related to opportunities using Salicaceae as a renewable resource. Challenges need to be resolved for every single step of the conversion process chain, i.e., starting from tree domestication for improved performance as a bioenergy crop, bioconversion process, policy development for land use changes associated with advanced biofuels, and harvest and supply logistics associated with industrial-scale biorefinery plants using Populus as feedstock. Significant hurdles towards cost and energy efficiency, environmental friendliness, and yield maximization with regards to biomass pretreatment, saccharification, and fermentation of celluloses and the sustainability of biorefineries as a whole still need to be overcome. PMID:25676392

Porth, Ilga; El-Kassaby, Yousry A

2015-04-01

375

Life cycle evaluation of emerging lignocellulosic ethanol conversion technologies.  

Science.gov (United States)

Lignocellulosic ethanol holds promise for addressing climate change and energy security issues associated with personal transportation through lowering the fuel mixes' carbon intensity and petroleum demand. We compare the technological features and life cycle environmental impacts of near- and mid-term ethanol bioconversion technologies in the United States. Key uncertainties in the major processes: pre-treatment, hydrolysis, and fermentation are evaluated. The potential to reduce fossil energy use and greenhouse gas (GHG) emissions varies among bioconversion processes, although all options studied are considerably more attractive than gasoline. Anticipated future performance is found to be considerably more attractive than that published in the literature as being achieved to date. Electricity co-product credits are important in characterizing the GHG impacts of different ethanol production pathways; however, in the absence of near-term liquid transportation fuel alternatives to gasoline, optimizing ethanol facilities to produce ethanol (as opposed to co-products) is important for reducing the carbon intensity of the road transportation sector and for energy security. PMID:19762231

Spatari, Sabrina; Bagley, David M; MacLean, Heather L

2010-01-01

376

Soluble inhibitors/deactivators of cellulase enzymes from lignocellulosic biomass.  

Science.gov (United States)

Liquid hot water, steam explosion, and dilute acid pretreatments of lignocellulose generate soluble inhibitors which hamper enzymatic hydrolysis as well as fermentation of sugars to ethanol. Toxic and inhibitory compounds will vary with pretreatment and include soluble sugars, furan derivatives (hydroxymethyl fulfural, furfural), organic acids (acetic, formic and, levulinic acid), and phenolic compounds. Their effect is seen when an increase in the concentration of pretreated biomass in a hydrolysis slurry results in decreased cellulose conversion, even though the ratio of enzyme to cellulose is kept constant. We used lignin-free cellulose, Solka Floc, combined with mixtures of soluble components released during pretreatment of wood, to prove that the decrease in the rate and extent of cellulose hydrolysis is due to a combination of enzyme inhibition and deactivation. The causative agents were extracted from wood pretreatment liquid using PEG surfactant, activated charcoal or ethyl acetate and then desorbed, recovered, and added back to a mixture of enzyme and cellulose. At enzyme loadings of either 1 or 25mg protein/g glucan, the most inhibitory components, later identified as phenolics, decreased the rate and extent of cellulose hydrolysis by half due to both inhibition and precipitation of the enzymes. Full enzyme activity occurred when the phenols were removed. Hence detoxification of pretreated woods through phenol removal is expected to reduce enzyme loadings, and therefore reduce enzyme costs, for a given level of cellulose conversion. PMID:22112958

Kim, Youngmi; Ximenes, Eduardo; Mosier, Nathan S; Ladisch, Michael R

2011-04-01

377

Switchable ionic liquids as delignification solvents for lignocellulosic materials.  

Science.gov (United States)

The transformation of lignocellulosic materials into potentially valuable resources is compromised by their complicated structure. Consequently, new economical and feasible conversion/fractionation techniques that render value-added products are intensely investigated. Herein an unorthodox and feasible fractionation method of birch chips (B. pendula) using a switchable ionic liquid (SIL) derived from an alkanol amine (monoethanol amine, MEA) and an organic super base (1,8-diazabicyclo-[5.4.0]-undec-7-ene, DBU) with two different trigger acid gases (CO2 and SO2 ) is studied. After SIL treatment, the dissolved fractions were selectively separated by a step-wise method using an antisolvent to induce precipitation. The SIL was recycled after concentration and evaporation of anti-solvent. The composition of undissolved wood after MEA-SO2 -SIL treatment resulted in 80 wt % cellulose, 10 wt % hemicelluloses, and 3 wt % lignin, whereas MEA-CO2 -SIL treatment resulted in 66 wt % cellulose, 12 wt % hemicelluloses and 11 wt % lignin. Thus, the MEA-SO2 -SIL proved more efficient than the MEA-CO2 -SIL, and a better solvent for lignin removal. All fractions were analyzed by gas chromatography (GC), Fourier transform infrared spectroscopy (FT-IR), (13) C nuclear magnetic resonance spectroscopy (NMR) and Gel permeation chromatography (GPC). PMID:24616172

Anugwom, Ikenna; Eta, Valerie; Virtanen, Pasi; Mäki-Arvela, Päivi; Hedenström, Mattias; Hummel, Michael; Sixta, Herbert; Mikkola, Jyri-Pekka

2014-04-01

378

[Determination of the nutritional value of lignocellulose materials].  

Science.gov (United States)

The determination of the nutritive value of various secondary wood products was conducted by the method of the in-vitro digestibility of dry matter (Mellenberger et al., 1970) and by detergent analyses of fibre (Goering and Van Soest, 1970). Rumen contents for trials in vitro were obtained from adult wethers having a permanent rumen fistula and fed good meadow hay ad lib. The animals also had free access to water and mineral lick for sheep. Out of the 11 lignocellulose materials tested, digestibility in vitro higher than 60% (equivalent to the digestibility of high-quality meadow hay) was only found in three samples. These are: a) beech sawdust II treated with 0.1M sulphuric acid at the hydromodulus of 1:8, temperature 100 to 130 degrees C for two hours, and pressure of 0.25 MPa and then with 0.47M nitric acid at the hydromodulus of 1:13, temperature 100 degrees C for two hours and pressure of 0.25 MPa; b) beech sawdust III treated as beech sawdust II and then neutralized with ammonia to pH 8; c) aspen sawdust treated hydrobarothermically at a temperature of 280 degrees C and pressure of 7 MPa in saturated vapour medium (Canon system). The high digestibility of these samples was due to a low lignin content so that the polysaccharides (cellulose and hemicelluloses) of these secondary wood sources could be sufficiently utilized by rumen microflora. PMID:6404041

Jalc, D; Zelenák, I; Bucko, J; Bod'a, K; Baran, M

1983-01-01

379

Screening of Fungi Capable of Degrading Lignocellulose from Plantation Forests  

Directory of Open Access Journals (Sweden)

Full Text Available In an effort to prevent forest fires after the clear cutting of plantation forests, fungi capable of degrading lignocelluloses were isolated to make a fertilizer from the logging waste. Seventy five fungal species were isolated from fruiting bodies and mycelia in plantation forests of South and North Sumatera, Indonesia. Sixty three of the fungi were identified based on the appearance and morphological characteristics of their fruiting bodies and mycelia, as Pycnoporus sanguineus, Dacryopinax spathularia, Schizophyllum commune, Polyporus sp. and Trametes sp. Twenty fungi were categorized as white-rot fungi and 12 as brown-rot fungi. Moreover, isolates 371, 368, 265, 346, 345 and 338 were selected using indicators and tested for the ability to degrade lignin and holo-cellulose in mangium wood meal over 1 to 4 weeks. Results showed that the 6 fungi could degrade lignin and holo-cellulose in wood meal. An increase in incubation time tended to decrease the amounts of lignin and holo-cellulose. Isolate 371 was found to be best at degrading lignin and holo-cellulose in mangium wood meal.

Djarwanto

2009-01-01

380

Screening of fungi capable of degrading lignocellulose from plantation forests.  

Science.gov (United States)

In an effort to prevent forest fires after the clear cutting of plantation forests, fungi capable of degrading lignocelluloses were isolated to make a fertilizer from the logging waste. Seventy five fungal species were isolated from fruiting bodies and mycelia in plantation forests of South and North Sumatera, Indonesia. Sixty three of the fungi were identified based on the appearance and morphological characteristics of their fruiting bodies and mycelia, as Pycnoporus sanguineus, Dacryopinax spathularia, Schizophyllum commune, Polyporus sp. and Trametes sp. Twenty fungi were categorized as white-rot fungi and 12 as brown-rot fungi. Moreover, isolates 371, 368, 265, 346, 345 and 338 were selected using indicators and tested for the ability to degrade lignin and holo-cellulose in mangium wood meal over 1 to 4 weeks. Results showed that the 6 fungi could degrade lignin and holo-cellulose in wood meal. An increase in incubation time tended to decrease the amounts of lignin and holo-cellulose. Isolate 371 was found to be best at degrading lignin and holo-cellulose in mangium wood meal. PMID:19634469

Djarwanto; Tachibana, S

2009-05-01

381

Validation of lignocellulosic biomass carbohydrates determination via acid hydrolysis.  

Science.gov (United States)

This work studied the two-step acid hydrolysis for determining carbohydrates in lignocellulosic biomass. Estimation of sugar loss based on acid hydrolyzed sugar standards or analysis of sugar derivatives was investigated. Four model substrates (starch, holocellulose, filter paper and cotton) and three levels of acid/material ratios (7.8, 10.3 and 15.4, v/w) were studied to demonstrate the range of test artifacts. The method for carbohydrates estimation based on acid hydrolyzed sugar standards having the most satisfactory carbohydrate recovery and relative standard deviation. Raw material and the acid/material ratio both had significant effect on carbohydrate hydrolysis, suggesting the acid to have impacts beyond a catalyst in the hydrolysis. Following optimal procedures, we were able to reach a carbohydrate recovery of 96% with a relative standard deviation less than 3%. The carbohydrates recovery lower than 100% was likely due to the incomplete hydrolysis of substrates, which was supported by scanning electron microscope (SEM) images. PMID:25129733

Zhou, Shengfei; Runge, Troy M

2014-11-01

382

New products made with lignocellulosic nanofibers from Brazilian amazon forest  

Science.gov (United States)

The biodiversity of the Amazon forest is undoubtedly rich; hence there is considerable variety of plant fibers regarding their morphological, chemical and structural properties. The legal exploration of the Brazilian Amazon is based on sustainable management techniques, but the generation of a relevant amount of plant wastes still cant be avoided. The correct destination of such materials is a challenge that Brazilian companies have to face. In this context, the National Council of Science and Technology (CNPq) promoted the creation of investigation nets on sustainability of Brazilian agribusiness. The Brazilian Net on Lignocellulosic Composites and Nanocomposites was then created, with partnership between several national and international research institutions. Until the moment, the results showed that Amazon plant fibers that are discarded as residues have great potential to nanofiber production. Nanopapers with considerable high mechanical and physical strength, proper opacity and great crystalline index were produced by using a clean and simple mechanical method. Those materials are candidates to several uses such as packaging, substrates transparent conductive films, gas barrier films, solar cells and e-papers.

Bufalino, L.; Mendes, L. M.; Tonoli, G. H. D.; Rodrigues, A.; Fonseca, A.; Cunha, P. I.; Marconcini, J. M.

2014-08-01

383

Surveillance instrumentation for spent-fuel safeguards  

International Nuclear Information System (INIS)

The movement, in a facility, of spent reactor fuel may be tracked using simple instrumentation together with a real time unfolding algorithm. Experimental measurements, from multiple radiation monitors and crane weight and position monitors, were obtained during spent fuel movements at the G.E. Morris Spent-Fuel Storage Facility. These data and a preliminary version of an unfolding algorithm were used to estimate the position of the centroid and the magnitude of the spent fuel radiation source. Spatial location was estimated to +-1.5 m and source magnitude to +-10% of their true values. Application of this surveillance instrumentation to spent-fuel safeguards is discussed

384

Protein hydrolysates from the alga Chlorella vulgaris 87/1 with potentialities in immuno nutrition  

International Nuclear Information System (INIS)

Chlorella vulgaris (Chlorophyta, Chlorophyceae) has received a particular attention in the programmes of microalgae utilisation in biotechnology. Enzymatic hydrolysis of cell proteins represents a very promising method to increase protein digestibility and thus, for obtaining hydrolysates with improved nutritional and functional properties. However, this technology has been little approached and the biological evaluation of hydrolysates has had a strictly nutritional nature. The design of hydrolysis conditions that combined for the first time, the use of C.vulgaris 87/1 treated with ethanol and pancreatin at pH values of 7.5-8.0, led to a product with a degree of hydrolysis of 20-22% and yields of 50-55%, characterised by a high digestibility (97.2%) and nitrogen solubility over a wide pH range (2.0-10.0). Hydrolysis curves were fitted to an exponential model, common to many food proteins. The bulk of the product dry matter consists of soluble peptides and free amino acids (47.7%) with three main peptides of molecular masses between 2 and 5 kDa. The oral administration of Chlorella hydrolysate (500 mg/kg) to undernourished Balb/c mice provided benefits in terms of liver protein metabolism and the induction of anabolic processes in gut mucosa. The hydrolysate also enhanced the immunological recovery, as judged by the stimulation of haemopoiesis, monocyte macrophage system activation, as well as humoral and cell mediated immune functions, like T-dependent antibody respofunctions, like T-dependent antibody response and the reconstitution of delayed-type hypersensitivity (DTH) response. These results represent the first findings in the world concerning the immunomodulating effects of a microalgae protein hydrolysate. (author)

385

Protein hydrolysates from the alga Chlorella vulgaris 87/1 with potentialities in immunonutrition  

Scientific Electronic Library Online (English)

Full Text Available SciELO Cuba | Language: English Abstract in english Chlorella vulgaris (Chlorophyta, Chlorophyceae) has received a particular attention in the programmes of microalgae utilisation in biotechnology. Enzymatic hydrolysis of cell proteins represents a very promising method to increase protein digestibility and thus, for obtaining hydrolysates with impro [...] ved nutritional and functional properties. However, this technology has been little approached and the biological evaluation of hydrolysates has had a strictly nutritional nature. The design of hydrolysis conditions that combined for the first time, the use of C.vulgaris 87/1 treated with ethanol and pancreatin at pH values of 7.5-8.0, led to a product with a degree of hydrolysis of 20-22% and yields of 50-55%, characterised by a high digestibility (97.2%) and nitrogen solubility over a wide pH range (2.0- 10.0). Hydrolysis curves were fitted to an exponential model, common to many food proteins. The bulk of the product dry matter consists of soluble peptides and free amino acids (47.7%) with three main peptides of molecular masses between 2 and 5 kDa. The oral administration of Chlorella hydrolysate (500 mg/kg) to undernourished Balb/c mice provided benefits in terms of liver protein metabolism and the induction of anabolic processes in gut mucosa. The hydrolysate also enhanced the immunological recovery, as judged by the stimulation of haemopoiesis, monocyte-macrophage system activation, as well as humoral and cell mediated immune functions, like T-dependent antibody response and the reconstitution of delayed-type hypersensitivity (DTH) response. These results represent the first findings in the world concerning the immunomodulating effects of a microalgae protein hydrolysate.

Humberto J, Morris; Olimpia V, Carrillo; Ángel, Almarales; Rosa C, Bermúdez; María E, Alonso; Leonardo, Borges; María M, Quintana; Roberto, Fontaine; Gabriel, Llauradó; Martha, Hernández.

2009-06-01

386

Amino acid composition and antioxidative peptides from protein hydrolysates of yellow stripe Trevally (Selaroides leptolepis).  

Science.gov (United States)

Hydrolysates from yellow stripe trevally meat with 15% degree of hydrolysis (DH) obtained using Alcalase (HA) and Flavourzyme (HF) following pH-stat method were characterized. Both hydrolysates, HA and HF, contained glutamic acid and glutamine as the major amino acids, while glycine was the dominant amino acid in fish flesh. Hydrolysates were also rich in aspartic acid, asparagine, alanine, lysine, and leucine. Essential amino acid/nonessential amino acid ratios were 0.55, 0.63, and 0.62 for flesh, HA, and HF, respectively. After separation on a Sephadex G-50 column, antioxidative activity of hydrolysate fractions was determined as Trolox equivalent antioxidant capacity. The fraction of HF with molecular weight (MW) of 1.77 kDa exhibited the strongest antioxidative activity, compared with other fractions. Among all fractions of HA, the one having a MW of 2.44 kDa showed the highest antioxidative activity. Thereafter, the selected Sephadex G-50 fractions from both HA and HF were further chromatographed using a Sephadex C-25 column, followed by HPLC. MW of antioxidative peptides from HA and HF determined by Maldi TOF/TOF was 656 and 617 Da, respectively. However, peptides isolated from both HA and HF possessed a lower antioxidative activity than Trolox at the same concentration (P < 0.05). HA and HF prevented DNA oxidative damage in Fenton reaction system tested by in vitro plasmid DNA relaxation assay. These results indicate that hydrolysates from yellow stripe trevally can be used as an important source of amino acids and serve as alternative natural antioxidants. PMID:19323726

Klompong, V; Benjakul, S; Yachai, M; Visessanguan, W; Shahidi, F; Hayes, K D

2009-03-01

387

Evaluation of bitterness in enzymatic hydrolysates of soy protein isolate by taste dilution analysis.  

Science.gov (United States)

Although enzymatic hydrolysates of soy protein isolate (SPI) have physiological functionality, partially hydrolyzed SPI exhibits bitter taste depending on proteases and degree of hydrolysis (DH). To determine proteolysis conditions for SPI, it is important to evaluate bitterness during enzymatic hydrolysis. Taste dilution analysis (TDA) has been developed for the screening technique of taste-active compounds in foods. The objectives of the present study were to evaluate bitterness of enzyme-hydrolyzed SPI by TDA and to compare bitterness of SPI hydrolysates with respect to kinds of proteases and DH. SPI was hydrolyzed at 50 degrees C and pH 6.8 to 7.1 to obtain various DH with commercial proteases (flavourzyme, alcalase, neutrase, protamex, papain, and bromelain) at E/S ratios of 0.5%, 1%, and 2%. The DH of enzymatic hydrolysates was measured by trinitrobenzenesulfonic acid method. The bitterness of enzymatic hydrolysates was evaluated by TDA, which is based on threshold detection in serially diluted samples. Taste dilution (TD) factor was defined as the dilution at which a taste difference between the diluted sample and 2 blanks could be detected. As DH increased, the bitterness increased for all proteases evaluated. Alcalase showed the highest TD factor at the same DH, followed by neutrase. Flavourzyme showed the lowest TD factor at the entire DH ranges. At the DH of 10%, TD factor of hydrolysate by flavourzyme was 0 whereas those by protamex and alcalase were 4 and 16, respectively. These results suggest that TDA could be applied for the alternative of bitterness evaluation to the hedonic scale sensory evaluation. PMID:18211368

Seo, W H; Lee, H G; Baek, H H

2008-01-01

388

Metals removal from spent salts  

Science.gov (United States)

A method and apparatus for removing metal contaminants from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents may be added to precipitate the metal oxide and/or the metal as either metal oxide, metal hydroxide, or as a salt. The precipitated materials are filtered, dried and packaged for disposal as waste or can be immobilized as ceramic pellets. More than about 90% of the metals and mineral residues (ashes) present are removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be spray-dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration salt solutions that contain less than 1.0 ppm of contaminants.

Hsu, Peter C. (Pleasanton, CA); Von Holtz, Erica H. (Livermore, CA); Hipple, David L. (Livermore, CA); Summers, Leslie J. (Livermore, CA); Brummond, William A. (Livermore, CA); Adamson, Martyn G. (Danville, CA)

2002-01-01

389

Xylose fermentation as a challenge for commercialization of lignocellulosic fuels and chemicals.  

Science.gov (United States)

Fuel ethanol production from lignocellulosic materials is at a level where commercial biofuel production is becoming a reality. The solubilization of the hemicellulose fraction in lignocellulosic-based feedstocks results in a large variety of sugar mixtures including xylose. However, allowing xylose fermentation in yeast that normally is used for fuel ethanol production requires genetic engineering. Moreover, the efficiency of lignocellulosic pretreatment, together with the release and generation of inhibitory compounds in this step, are some of the new challenges faced during second generation ethanol production. Successful advances in all these aspects will improve ethanol yield, productivity and titer, which will reduce the impact on capital and operating costs, leading to the consolidation of the fermentation of lignocellulosic biomass as an economically feasible option for the production of renewable fuels. Therefore the development of yeast strains capable of fermenting a wide variety of sugars in a highly inhibitory environment, while maintaining a high ethanol yield and production rate, is required. This review provides an overview of the current status in the use of xylose-engineered yeast strains and describes the remaining challenges to achieve an efficient deployment of lignocellulosic-based ethanol production. PMID:25522734

Sànchez Nogué, Violeta; Karhumaa, Kaisa

2015-04-01

390

Sonochemistry: what potential for conversion of lignocellulosic biomass into platform chemicals?  

Science.gov (United States)

This Review focuses on the use of ultrasound to produce chemicals from lignocellulosic biomass. However, the question about the potential of sonochemistry for valorization/conversion of lignocellulosic biomass into added-value chemicals is rather conceptual. Until now, this technology has been mainly used for the production of low-value chemicals such as biodiesel or as simple method for pretreatment or extraction. According to preliminary studies reported in literature, access to added-value chemicals can be easily and sometimes solely obtained by the use of ultrasound. The design of sonochemical parameters offers many opportunities to develop new eco-friendly and efficient processes. The goal of this Review is to understand why the use of ultrasound is focused rather on pretreatment or extraction of lignocellulosic biomass rather than on the production of chemicals and to understand, through the reported examples, which directions need to be followed to favor strategies based on ultrasound-assisted production of chemicals from lignocellulosic biomass. We believe that ultrasound-assisted processes represent an innovative approach and will create a growing interest in academia but also in the industry in the near future. Based on the examples reported in the literature, we critically discuss how sonochemistry could offer new strategies and give rise to new results in lignocellulosic biomass valorization. PMID:25146583

Chatel, Gregory; De Oliveira Vigier, Karine; Jérôme, François

2014-10-01

391

A review of biological delignification and detoxification methods for lignocellulosic bioethanol production.  

Science.gov (United States)

Abstract Future biorefineries will integrate biomass conversion processes to produce fuels, power, heat and value-added chemicals. Due to its low price and wide distribution, lignocellulosic biomass is expected to play an important role toward this goal. Regarding renewable biofuel production, bioethanol from lignocellulosic feedstocks is considered the most feasible option for fossil fuels replacement since these raw materials do not compete with food or feed crops. In the overall process, lignin, the natural barrier of the lignocellulosic biomass, represents an important limiting factor in biomass digestibility. In order to reduce the recalcitrant structure of lignocellulose, biological pretreatments have been promoted as sustainable and environmentally friendly alternatives to traditional physico-chemical technologies, which are expensive and pollute the environment. These approaches include the use of diverse white-rot fungi and/or ligninolytic enzymes, which disrupt lignin polymers and facilitate the bioconversion of the sugar fraction into ethanol. As there is still no suitable biological pretreatment technology ready to scale up in an industrial context, white-rot fungi and/or ligninolytic enzymes have also been proposed to overcome, in a separated or in situ biodetoxification step, the effect of the inhibitors produced by non-biological pretreatments. The present work reviews the latest studies regarding the application of different microorganisms or enzymes as useful and environmentally friendly delignification and detoxification technologies for lignocellulosic biofuel production. This review also points out the main challenges and possible ways to make these technologies a reality for the bioethanol industry. PMID:24506661

Moreno, Antonio D; Ibarra, David; Alvira, Pablo; Tomás-Pejó, Elia; Ballesteros, Mercedes

2014-02-10

392

Spent fuel receipt scenarios study  

International Nuclear Information System (INIS)

This study reports on the results of an assignment from the DOE Office of Civilian Radioactive Waste Management to evaluate of the effects of different scenarios for receipt of spent fuel on the potential performance of the waste packages in the proposed Yucca Mountain high-level waste repository. The initial evaluations were performed and an interim letter report was prepared during the fall of 1988. Subsequently, the scope of work was expanded and additional analyses were conducted in 1989. This report combines the results of the two phases of the activity. This study is a part of a broader effort to investigate the options available to the DOE and the nuclear utilities for selection of spent fuel for acceptance into the Federal Waste Management System for disposal. Each major element of the system has evaluated the effects of various options on its own operations, with the objective of providing the basis for performing system-wide trade-offs and determining an optimum acceptance scenario. Therefore, this study considers different scenarios for receipt of spent fuel by the repository only from the narrow perspective of their effect on the very-near-field temperatures in the repository following permanent closure. This report is organized into three main sections. The balance of this section is devoted to a statement of the study objective, a summary of the assumptions. The second section of the report contains a discussion of the major elements of the study. The third section summarizes the results of the study and draws some conclusions from them. The appendices include copies of the waste acceptance schedule and the existing and projected spent fuel inventory that were used in the study. 10 refs., 27 figs

393

Spent nuclear fuel storage racks  

International Nuclear Information System (INIS)

A storage rack in which a plurality of tubular shrouds are assembled together in a checkerboard arrangement, each shroud having side walls arranged to absorb sub-atomic particles such as neutrons. With this arrangement, spent atomic fuel rods may be assembled in the shrouds and also in the spaces which are surrounded by shrouds, so that each adjacent grouping of fuel rods has interposed therebetween an emission absorbing wall

394

Spent fuel integrity during transportation  

International Nuclear Information System (INIS)

The conditions of recent shipments of light water reactor spent fuel were surveyed. The radioactivity level of cask coolant was examined in an attempt to find the effects of transportation on LWR fuel assemblies. Discussion included potential cladding integrity loss mechanisms, canning requirements, changes of radioactivity levels, and comparison of transportation in wet or dry media. Although integrity loss or degradation has not been identified, radioactivity levels usually increase during transportation, especially for leaking assemblies

395

Projected spent fuel storage requirements  

International Nuclear Information System (INIS)

This analysis identifies the post-reactor basin storage capacity requirements between now and 1990 for various combinations of utility actions in order to establish the full range of possible storage requirements. The combined actions of reracking reactor basins, transferring spent fuel within utilities, and relaxing the policy of reserving reactor basin capacity for a full core discharge are insufficient to meet pre-1985 spent fuel storage capacity requirements. Additional storage capacity is required before 1985 for at least 1000 BWR assemblies and 2000 PWR assemblies. Storage capacity must be provided for a minimum of 12,000 BWR assemblies and 7,000 PWR assemblies by 1990. If none of the possible industry actions are taken, additional storage capacity is required for over 23,000 BWR and 17,000 PWR assemblies before 1985 and over 63,000 BWR and 40,000 PWR assemblies by 1990. The amount of spent fuel which would be shipped to a post reactor basin storage facility between 1985 and 1990 depends on whether utilities continue the activities and policies required to meet spent fuel storage requirements before 1985 (no full core reserve, intra-utility fuel shipments) or seek to regain their pre-storage shortage posture (full core reserve capacity, no intra-utility fuel shipments). If utilities take the former approach, storage capacity is required between 1985 and 1990 for approximately 11,000 BWR assemblies and 5,000 PWR assemblies. If the latter philososphy prevails, storage capacity must be provided between 1895 and 1990 for approximately 27,000 BWR assemblies and 23,000 PWR assemblies

396

Biological treatment of spent caustics.  

OpenAIRE

A process for the biological treatment of a spent caustic solution containing sulphides is disclosed, wherein the solution is introduced into an aerobic reactor containing sulphide-oxidising bacteria, and the sulphides are partly converted to elemental sulphur and partly to sulphate by controlling the redox potential in the reactor at a value below -300 mV (against an Ag/AgCl reference electrode), or below -97 (against a H2 reference electrode). Also disclosed is process for the biological tr...

Janssen, A. J. H.; Buisman, C.; Lettinga, G.; Straten, G.; Bontsema, J.; Kuenen, J. G.; Zwart, J. M. M.

1996-01-01

397

Extended storage of spent fuel  

International Nuclear Information System (INIS)

This document is the final report on the IAEA Co-ordinated Research Programme on the Behaviour of Spent Fuel and Storage Facility Components during Long Term Storage (BEFAST-II, 1986-1991). It contains the results on wet and dry spent fuel storage technologies obtained from 16 organizations representing 13 countries who participated in the co-ordinated research programme. Considerable quantities of spent fuel continue to arise and accumulate. Many countries are investigating the option of extended spent fuel storage prior to reprocessing or fuel disposal. Wet storage continues to predominate as an established technology with the construction of additional away-from-reactor storage pools. However, dry storage is increasingly used with most participants considering dry storage concepts for the longer term. Depending on the cladding type options of dry storage in air or inert gas are proposed. Dry storage is becoming widely used as a supplement to wet storage for zirconium alloy clad oxide fuels. Storage periods as long as under wet conditions appear to be feasible. Dry storage will also continue to be used for Al clad and Magnox type fuel. Enhancement of wet storage capacity will remain an important activity. Rod consolidation to increase wet storage capacity will continue in the UK and is being evaluated for LWR fuel in the USA, and may start in some other countries. High density storage racks have been successfully introduced in many existing pools and are planned for future facilities. For extremely long wet storage (?50 years), there is a need to continue work on fuel integrity investigations and LWR fuel performance modelling. it might be that pool component performance in some cases could be more limiting than the FA storage performance. It is desirable to make concerted efforts in the field of corrosion monitoring and prediction of fuel cladding and poll component behaviour in order to maintain good experience of wet storage. Refs, figs and tabs

398

Spent fuel management in Argentina  

International Nuclear Information System (INIS)

The current Argentine nuclear power programme consists of HWR reactors: two in operation (Atucha-I, 345 MWe and EMBALSE, 600 MWe) one 745 MWe is under construction and another one, 700 MWe will be installed before the end of the century. Plans for spent fuel storage and active programme for the utilization of Mixed Oxide (U-235, Pu-239) fuel which allows the development of technology for reprocessing and MOX fuel fabrication on a pilot plant are described. (author)

399

Reuse of Hydrotreating Spent Catalyst  

International Nuclear Information System (INIS)

All hydro treating catalysts used in petroleum refining processes gradually lose activity through coking, poisoning by metal, sulfur or halides or lose surface area from sintering at high process temperatures. Waste hydrotreating catalyst, which have been used in re-refining of waste lube oil at Alexandria Petroleum Company (after 5 years lifetime) compared with the same fresh catalyst were used in the present work. Studies are conducted on partial extraction of the active metals of spent catalyst (Mo and Ni) using three leaching solvents,4% oxidized oxalic acid, 10% aqueous sodium hydroxide and 10% citric acid. The leaching experiments are conducting on the de coked extrude [un crushed] spent catalyst samples. These steps are carried out in order to rejuvenate the spent catalyst to be reused in other reactions. The results indicated that 4% oxidized oxalic acid leaching solution gave total metal removal 45.6 for de coked catalyst samples while NaOH gave 35% and citric acid gave 31.9 % The oxidized leaching agent was the most efficient leaching solvent to facilitate the metal removal, and the rejuvenated catalyst was characterized by the unchanged crystalline phase The rejuvenated catalyst was applied for hydrodesulfurization (HDS) of vacuum gas oil as a feedstock, under different hydrogen pressure 20-80 bar in order to compare its HDS activity

400

Spent fuel reprocessing: an overview  

International Nuclear Information System (INIS)

In seventies, India has entered in the field of reprocessing of spent fuel arising from power reactor by way of design, erection and commissioning of a reprocessing plant at Tarapur (PREFRE) and subsequently one more reprocessing plant has been commissioned at Kalpakkam (KARP). Presently, spent fuel from KAPS and MAPS are being reprocessed at PREFRE Tarapur and KARP Kalpakkam respectively and fuel from Dhruva and CIRUS is being reprocessed at Plutonium Plant, Trombay. Recently, the country has also developed the process flow sheet for separation of uranium from thorium rod irradiated in a research reactor and this has been demonstrated by successful commissioning of a plant at BARC, Trombay (UTSF) and recovered uranium is being used for various programmes of the department. Design work is also in progress for separation of uranium from thorium rod irradiated in power reactor. R and D activities are also going on for development of process flow sheet for reprocessing of spent fuel which will be arising from AHWR in near future

401

Criticality of spent reactor fuel  

International Nuclear Information System (INIS)

The storage capacity of spent reactor fuel pools can be greatly increased by consolidation. In this process, the fuel rods are removed from reactor fuel assemblies and are stored in close-packed arrays in a canister or skeleton. An earlier study examined criticality consideration for consolidation of Westinghouse fuel, assumed to be fresh, in canisters at the Millstone-2 spent-fuel pool and in the General Electric IF-300 shipping cask. The conclusions were that the fuel rods in the canister are so deficient in water that they are adequately subcritical, both in normal and in off-normal conditions. One potential accident, the water spill event, remained unresolved in the earlier study. A methodology is developed here for spent-fuel criticality and is applied to the water spill event. The methodology utilizes LEOPARD to compute few-group cross sections for the diffusion code PDQ7, which then is used to compute reactivity. These codes give results for fresh fuel that are in good agreement with KENO IV-NITAWL Monte Carlo results, which themselves are in good agreement with continuous energy Monte Carlo calculations. These methodologies are in reasonable agreement with critical measurements for undepleted fuel

402

Spent Fuel Working Group Report  

International Nuclear Information System (INIS)

The Department of Energy is storing large amounts of spent nuclear fuel and other reactor irradiated nuclear materials (herein referred to as RINM). In the past, the Department reprocessed RINM to recover plutonium, tritium, and other isotopes. However, the Department has ceased or is phasing out reprocessing operations. As a consequence, Department facilities designed, constructed, and operated to store RINM for relatively short periods of time now store RINM, pending decisions on the disposition of these materials. The extended use of the facilities, combined with their known degradation and that of their stored materials, has led to uncertainties about safety. To ensure that extended storage is safe (i.e., that protection exists for workers, the public, and the environment), the conditions of these storage facilities had to be assessed. The compelling need for such an assessment led to the Secretary's initiative on spent fuel, which is the subject of this report. This report comprises three volumes: Volume I; Summary Results of the Spent Fuel Working Group Evaluation; Volume II, Working Group Assessment Team Reports and Protocol; Volume III; Operating Contractor Site Team Reports. This volume presents the overall results of the Working Group's Evaluation. The group assessed 66 facilities spread across 11 sites. It identified: (1) facilities that should be considered for priority attention. (2) programmatic issues to be considered in decision making about interim storage plans and (3) specific vulnerabilities for some of these facilities

403

Spent fuel management in the Slovak Republic  

International Nuclear Information System (INIS)

Presentation describes the history, present and future of the spent fuel management in the Slovak Republic. First experiences with spent fuel were gained in the seventies. Spent fuel form A-1 NPP was handled at Jaslovske Bohunice site, in order to prepare the spent fuel for the transport to the former USSR. After shut down of the A-1 NPP, all spent fuel was transported to the USSR. In 1978 first unit of V-1 NPP was set into operation. Actually there are six NPP units of the WWER type at Jaslovske Bohunice and Mochovce sites in operation in the Slovak Republic. These six units produce about 500 spent fuel assemblies per year. In 1988 an Interim spent fuel storage facility was build at Jaslovske Bohunice site. These facility stores spent fuel from four Jaslovske Bohunice units. In 2000 this facility was subject to a reconstruction, seismic upgrade and capacity enlargement. In 2004 Nuclear Regulatory Authority of the Slovak Republic approved transport container C-30 for transport of forty-eight spent fuel assemblies. The transport capacity has risen, so the number of transports could be reduced. In 2006 Slovak Electric Plc. (SE) will start transports of spent fuel from Mochovce site to Interim spent fuel storage facility (ISFSF) Jaslovske Bohunice. In addition, a project of Interim spent fuel storage facility at Mochovce site is going on. In the future Slovakia plans to find definitive solution for the spent fuel. One solution could be reprocessing and further usage in the power reactors, the other solution could be final deposition of spent fuel. (author)

404

Relative contributions of bacteria and fungi to rates of degradation of lignocellulosic detritus in salt-marsh sediments  

International Nuclear Information System (INIS)

Specifically radiolabeled [14C-lignin]lignocellulose and [14C-polysaccharide]lignocellulose from the salt-marsh cordgrass Spartina alterniflora were incubated with an intact salt-marsh sediment microbial assemblage, with a mixed (size-fractionated) bacterial assemblage, and with each of three marine fungi, Buergenerula spartinae, Phaeosphaeria typharum, and Leptosphaeria obiones, isolated from decaying S. alterniflora. The bacterial assemblage alone mineralized the lignin and polysaccharide components of S. alterniflora lignocellulose at approximately the same rate as did intact salt-marsh sediment inocula. The polysaccharide component was mineralized twice as fast as the lignin component; after 23 days of incubation, ca. 10% of the lignin component and 20% of the polysaccharide component of S. alterniflora lignocellulose were mineralized. Relative to the total sediment and bacterial inocula, the three species of fungi mediated only very slow mineralization of the lignin and polysaccharide components of S. alterniflora lignocellulose. Experiments with uniformly 14C-labeled S. alterniflora material indicated that the three fungi and the bacterial assemblage were capable of degrading the non-lignocellulosic fraction of S. alterniflora material, but only the bacterial assemblage significantly degraded the lignocellulosic fraction. Our results suggest that bacteria are the predominant degraders of lignocellulosic detritus in salt-march sedlignocellulosic detritus in salt-march sediments

405

Preparation, characterization, and microbial degradation of specifically radiolabeled [14C]lignocelluloses from marine and fresh water macrophytes  

International Nuclear Information System (INIS)

Specifically radiolabeled [14C-lignin]lignocelluloses were prepared from the aquatic macrophytes Spartina alterniflora, Juncus roemerianus, Rhizophora mangle, and Carex walteriana by using [14C]phenylalanine, [14C]tyrosine, and [14C]cinnamic acid as precursors. Specifically radiolabeled [14C-polysaccharide]lignocelluloses were prepared by using [14C]glucose as precursor. The rates of microbial degradation varied among [14C-lignin]lignocelluloses labeled with different lignin precursors within the same plant species. In herbaceous plants, significant amounts (8 to 24%) of radioactivity from [14C]phenylalanine and [14C]tyrosine were found associated with protein. Microbial degradation of radiolabeled protein resulted in overestimation of lignin degradation rates in lignocelluloses derived from herbaceous aquatic plants. Other differences in degradation rates among [14C-lignin]lignocelluloses from the same plant species were attributable to differences in the amount of label being associated with ester-linked subunits of peripheral lignin. After acid hydrolysis of [14C-polysaccharide]lignocelluloses, radioactivity was detected in several sugars, although most of the radioactivity was distributed between glucose and xylose. After 576 h of incubation with salt marsh sediments, 38% of the polysaccharide component and between 6 and 16% of the lignin componand between 6 and 16% of the lignin component (depending on the precursor) of J. roemerianus lignocellulose was mineralized to 14CO2; during the same incubation period, 30% of the polysaccharide component and between 12 and 18% of the lignin component of S. alterniflora lignocellulose was mineralized

406

Spent fuel management in Poland  

International Nuclear Information System (INIS)

Full text: The problems with spent nuclear fuel management were beginning in Poland at the moment of discharge of first fuel assembly used research reactor EWA at 1959. It was water-moderated reactor with Ek10 type fuel rods, operated at 2 MW thermal power. In 1966 the EWA reactor was rebuild and new type fuel assemblies: WWR-SM and WWR-M2 were used. The power of reactor was changed up to 10 MW. EWA reactor was operated until February 1995. Spent Ek-10 fuel rods and WWR spent fuel assemblies are stored in water pools in two away from reactor storage facilities. The basic design information on these facilities and experience from their operation are presented in the present presentation. In 1974 the new research reactor MARIA reached criticality and start operation from 1975. This is water beryllium moderated reactor with MR6 or MR5 fuel assemblies. The maximum thermal power is 30 MW. Up to 2000, the fuel assemblies with 80 % enrichment uranium were used. Now, the medium enrichment (36 %) fuel assemblies were used. The spent MR type fuel was stored in at reactor storage tank. The experience with operation of storage pool is presented. Taking into account the fact that the fuel was stored for the long period of time in wet condition, the wide program of physical investigation of spent fuel and storage facilities was carried out. The visual investigation of cladding material was performed. Only initial cladding corrosion was observed for the fuel with 20 years of storagerved for the fuel with 20 years of storage, and the strong corrosion process was visible on elements stored for 30 years. It was observed that corrosion processes is faster if fuel meat is present under cladding material. On the basis of the results of the sipping tests of WWR-SM fuel assemblies with different storage time (from 4 to 31 years), the assessment of the time limit of their storage in wet condition has been made. Based on this assessment, the value of the daily leakage of Cs-137 from WWR-SM and WWR-M2 spent fuel in the wet pool was estimated and compared with the measurements performed in 1999 and 2000. The results of systematic sipping tests of Ek-10 fuel rods and WWR-SM fuel assemblies discharged from EWA reactor before 1970 is presented in the paper. The remote ultrasonic scanning was used for pit corrosion profile determination. The condition of the stainless steel liner and aluminium tank of the storage pool was investigated. For this purpose the wide range of techniques e.g. penetrating, ultrasonic was applied. On the basis of the investigation necessary repairs of facility were made. Taking into account the fact that storage in wet condition is limited in time, the technology of encapsulation of spent MR type fuel assemblies was in helium atmosphere elaborated and used after approval by Polish Regulatory Body. Tents of MR assemblies were encapsulated successfully. The technology of encapsulation of Ek-10 fuel rods and WWR fuel assemblies are under elaboration. The concept of dry storage facility is presented

407

Bioethanol Production from Lignocellulosic Feedstocks Based on Enzymatic Hydrolysis: Current Status and Recent Developments  

Directory of Open Access Journals (Sweden)

Full Text Available All over the world, research on bioethanol production has grown with increasing of energy needs and it has become a research area of great interest to many governments, academic groups and companies. Ethanol which is presently the most common renewable fuel, can be produced biologically from a variety of feedstocks and wastes. Due to advances in agriculture and biotechnology one can envision inexpensive production of ethanol based on lignocellulosic biomass. This review summarizes various processes involved in lignocellulosic-derived biofuel bioconversion. Several methods of pretreatment of lignocelluloses are discussed. Characteristics of enzymes and important factors in enzymatic hydrolysis of the cellulose and hemicellulose are reviewed. Different strategies are then described and illustrated in a simpler form for enzymatic hydrolysis and fermentation, including separate enzymatic hydrolysis and fermentation, simultaneous saccharification and fermentation, simultaneous saccharification and co-fermentation and consolidated bioprocessing. Furthermore, recent trends, major challenges and perspective of future development are highlighted.

Noura El-Ahmady El-Naggar

2014-01-01

408

LIGNOCELLULOSIC FEEDSTOCK BIOREFINERY—THE FUTURE OF CHEMICAL AND ENERGY INDUSTRY  

Directory of Open Access Journals (Sweden)

Full Text Available The sustainable development of the chemical and energy industry is an indispensable component of our sustainable society. However, the traditional chemical and energy industry depends heavily on such non-renewable fossil resources as oil, coal, and natural gas. Its feedstock shortage and the resultant environmental and climatic problems pose a great threat for any type of sustainable development. Lignocellulosic materials are the most abundant renewable resources in the world and their efficient utilization provides a practical route to address these challenges. The lignocellulosic feedstock bio-refinery is an effective model for the comprehensive utilization of lignocellulosic materials, and it will play vital role in the future development of chemical and energy industry.

Shengdong Zhu

2009-05-01

409

Augmented digestion of lignocellulose by steam explosion, acid and alkaline pretreatment methods: a review.  

Science.gov (United States)

Lignocellulosic materials can be explored as one of the sustainable substrates for bioethanol production through microbial intervention as they are abundant, cheap and renewable. But at the same time, their recalcitrant structure makes the conversion process more cumbersome owing to their chemical composition which adversely affects the efficiency of bioethanol production. Therefore, the technical approaches to overcome recalcitrance of biomass feedstock has been developed to remove the barriers with the help of pretreatment methods which make cellulose more accessible to the hydrolytic enzymes, secreted by the microorganisms, for its conversion to glucose. Pretreatment of lignocellulosic biomass in cost effective manner is a major challenge to bioethanol technology research and development. Hence, in this review, we have discussed various aspects of three commonly used pretreatment methods, viz., steam explosion, acid and alkaline, applied on various lignocellulosic biomasses to augment their digestibility alongwith the challenges associated with their processing. PMID:25498680

Singh, Joginder; Suhag, Meenakshi; Dhaka, Anil

2015-03-01

410

Saccharification of Miscanthus x giganteus, incorporation of lignocellulosic by-product in cementitious matrix.  

Science.gov (United States)

Given the non competition of miscanthus with food and animal feed, this lignocellulosic species has attracted attention as a possible biofuel resource. However, sustainability of ethanol production from lignocelluloses biomass would imply reduction in the consumption of chemicals and/or energetic means, but also valorization of the lignocellulosic by-product remaining from enzymatic saccharification. Introduction of these by-products into a cementitious matrix could be used in manufacturing a lightweight composite. Miscanthus biomass was submitted to chemical pretreatments followed by saccharification using an enzymatic cocktail. Residues from saccharification were then mixed with a cementitious matrix. Given their mechanical properties and a good adherence between cement and by-product, the hardened materials could be used. However, the delay in the beginning of setting time is too long, which prevents the direct use of by-product into cementitious matrix. Preliminary experiments using a setting accelerator in the cementitious matrix permitted significant reduction in the setting time delay. PMID:22078741

Le Ngoc Huyen, Tran; Queneudec T'kint, Michèle; Remond, Caroline; Chabbert, Brigitte; Dheilly, Rose-Marie

2011-11-01

411

High performance maleated lignocellulose epicarp fibers for copper ion removal  

Scientific Electronic Library Online (English)

Full Text Available Natural lignocellulosic fiber epicarp extracted from the babassu coconut (Orbignya speciosa) was chemically modified through reaction with molten maleic anhydride without solvent, with incorporation of 189.34 mg g-1 of carboxylic acid groups into the biopolymer structure. The success of this reactio [...] n was also confirmed by the presence of carboxylic acid bands at 1741 and 1164 cm-1 in the infrared spectrum. Identically, the same group is observed through 13C NMR CP/MAS in the solid state, via high field signals in the 167 pm region. Both the precursor and the immobilized maleated biopolymers presented nearly the same thermal stability and similar crystallinity to cellulose. However, the pendant carboxylic groups have the ability to remove copper with maximum sorption through a batchwise process at pH 6.0, as expected from the point of zero charge, determined to be 6.45. The sorption kinetic data were fitted to pseudo-first order, pseudo-second order, Elovich-chemisorption and intra-particle diffusion models and the equilibrium data were fitted to the Langmuir, the Freundlich and Tenkim isotherm models. Taking into account a statistical error function and determination coefficients, the data were fit to the pseudo-first and pseudo-second order kinetic and Langmuir isotherm models, with a maximum sorption capacity of copper ions of 55.09 mg g-1. This value suggests the application of this biopolymer with incorporated carboxylate groups as a favorable agent for copper removal from appropriate systems.

A. P., Vieira; S. A. A., Santana; C. W. B., Bezerra; H. A. S., Silva; K. C. A., Santos; J. C. P., Melo; E. C., Silva Filho; C., Airoldi.

2014-03-01

412

Typical Lignocellulose-degrading Enzymes: a Synthesis of Kinetic Properties  

Science.gov (United States)

While soil enzymes have been explicitly included in the soil organic carbon (SOC) decomposition models, there are big concerns on the model parameterization. Our object is to study the kinetic parameters of five typical lignocellulose-degrading enzymes through literature research and data synthesis. The kinetic parameters refer to the maximum specific enzyme activity (Vmax) and half-saturation constant (Km) in the Michaelis-Menton equation. The Activation energy (Ea) and the pH optimum and sensitivity (pHopt and pHsen) were also analyzed. pHsen was estimated by curve fitting of an exponential-quadratic function. The Vmax values in different units under various conditions were converted into the same units at a reference temperature (20°C) and optimum pH. The scaling issue on Vmax and Km and the effects of soil temperature, pH, and SWC were discussed later. Major findings are summarized as follows. (i) Both Vmax and Km are log-normal distributed. (ii) No significant difference in Vmax is found between groups (ligninases and cellulases). The one-standard-deviation interval of Vmax falls within 10-1000 (mean ? 100) mg C mg^-1 Enz h^-1. However, there is significant difference in Km between groups. (iii) Significant difference in activation energy, i.e., 53±17 and 37±15 kJ mol^-1 is found for ligninases and cellulases, respectively. (iv) Both ligninases and cellulases prefer to acid environment. The average ratio of pHsen to pHopt ranges 0.3-0.4 and the optimum pH for ligninases is significantly lower than pHopt for cellulases. (v) A preliminary analysis of Vmax indicates a scaling factor 0.01-0.1 for transforming the Vmax from lab measurements to SOC decomposition models. This study provides useful information for the parameterization of enzyme-driven SOC decomposition models.

Wang, G.; Post, W. M.; Mayes, M. A.; Frerichs, J.; Jagadamma, S.

2011-12-01

413

Spent nuclear fuel storage - Basic concept  

Energy Technology Data Exchange (ETDEWEB)

According to the procedures adopted in others countries in the world, the spent nuclear fuel elements burned to produce electrical energy in the Brazilian Nuclear Power Plant of Angra do Reis, Central Nuclear Almirante Alvaro Alberto - CNAAA will be stored for a long time. Such procedure will allow the next generation to decide how they will handle those materials. In the future, the reprocessing of the nuclear fuel assemblies could be a good solution in order to have additional energy resource and also to decrease the volume of discarded materials. This decision will be done in the future according to the new studies and investigations that are being studied around the world. The present proposal to handle the nuclear spent fuel is to storage it for a long period of time, under institutional control. Therefore, the aim of this paper is to introduce a proposal of a basic concept of spent fuel storage, which involves the construction of a new storage building at site, in order to increase the present storage capacity of spent fuel assemblies in CNAAA installation; the concept of the spent fuel transportation casks that will transfer the spent fuel assemblies from the power plants to the Spent Fuel Complementary Storage Building and later on from this building to the Long Term Intermediate Storage of Spent Fuel; the concept of the spent fuel canister and finally the basic concept of the spent fuel long term storage. (author)

Krempel, Ascanio; Santos, Cicero D. Pacifici dos; Sato, Heitor Hitoshi; Magalhaes, Leonardo de [ELETROBRAS Termonuclear S.A. - ELETRONUCLEAR, Rio de Janeiro, RJ (Brazil). Dept. GTP.T - DT], e-mail: ascanio@eletronuclear.gov.br, e-mail: cicero@eletronuclear.gov.br, e-mail: hitoshi@eletronuclear.gov.br, e-mail: leomag@eletronuclear.gov.br

2009-07-01

414

Spent nuclear fuel storage - Basic concept  

International Nuclear Information System (INIS)

According to the procedures adopted in others countries in the world, the spent nuclear fuel elements burned to produce electrical energy in the Brazilian Nuclear Power Plant of Angra do Reis, Central Nuclear Almirante Alvaro Alberto - CNAAA will be stored for a long time. Such procedure will allow the next generation to decide how they will handle those materials. In the future, the reprocessing of the nuclear fuel assemblies could be a good solution in order to have additional energy resource and also to decrease the volume of discarded materials. This decision will be done in the future according to the new studies and investigations that are being studied around the world. The present proposal to handle the nuclear spent fuel is to storage it for a long period of time, under institutional control. Therefore, the aim of this paper is to introduce a proposal of a basic concept of spent fuel storage, which involves the construction of a new storage building at site, in order to increase the present storage capacity of spent fuel assemblies in CNAAA installation; the concept of the spent fuel transportation casks that will transfer the spent fuel assemblies from the power plants to the Spent Fuel Complementary Storage Building and later on from this building to the Long Term Intermediate Storage of Spent Fuel; the concept of the spent fuel canister and finally the basic concept of the spent fuel long term storage. (author)

415

Biological pretreatment of lignocellulosic substrates for enhanced delignification and enzymatic digestibility.  

Science.gov (United States)

Sheer enormity of lignocellulosics makes them potential feedstock for biofuel production but, their conversion into fermentable sugars is a major hurdle. They have to be pretreated physically, chemically, or biologically to be used by fermenting organisms for production of ethanol. Each lignocellulosic substrate is a complex mix of cellulose, hemicellulose and lignin, bound in a matrix. While cellulose and hemicellulose yield fermentable sugars, lignin is the most recalcitrant polymer, consisting of phenyl-propanoid units. Many microorganisms in nature are able to attack and degrade lignin, thus making access to cellulose easy. Such organisms are abundantly found in forest leaf litter/composts and especially include the wood rotting fungi, actinomycetes and bacteria. These microorganisms possess enzyme systems to attack, depolymerize and degrade the polymers in lignocellulosic substrates. Current pretreatment research is targeted towards developing processes which are mild, economical and environment friendly facilitating subsequent saccharification of cellulose and its fermentation to ethanol. Besides being the critical step, pretreatment is also cost intensive. Biological treatments with white rot fungi and Streptomyces have been studied for delignification of pulp, increasing digestibility of lignocellulosics for animal feed and for bioremediation of paper mill effluents. Such lignocellulolytic organisms can prove extremely useful in production of bioethanol when used for removal of lignin from lignocellulosic substrate and also for cellulase production. Our studies on treatment of hardwood and softwood residues with Streptomyces griseus isolated from leaf litter showed that it enhanced the mild alkaline solubilisation of lignins and also produced high levels of the cellulase complex when growing on wood substrates. Lignin loss (Klason lignin) observed was 10.5 and 23.5% in case of soft wood and hard wood, respectively. Thus, biological pretreatment process for lignocellulosic substrate using lignolytic organisms such as actinomycetes and white rot fungi can be developed for facilitating efficient enzymatic digestibility of cellulose. PMID:23729871

Saritha, M; Arora, Anju; Lata

2012-06-01

416