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Ethanolic fermentation of lignocellulose hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

This minireview discusses various factors which require consideration for the ethanolic fermentation of lignocellulose hydrolysates. The production of an alternative transportation fuel requires pretreatment of the biomass and detoxification to enhance the fermentability. Recombinant DNA technology makes it possible to engineer new microorganisms for efficient ethanol production from all sugars present in the hydrolysates. 60 refs.

Hahn-Haegerdal, B. [Lund Univ. (Sweden)

1996-12-31

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Detoxification of lignocellulosic hydrolysates using sodium borohydride.  

Science.gov (United States)

Addition of sodium borohydride to a lignocellulose hydrolysate of Norway spruce affected the fermentability when cellulosic ethanol was produced using Saccharomyces cerevisiae. Treatment of the hydrolysate with borohydride improved the ethanol yield on consumed sugar from 0.09 to 0.31 g/g, the balanced ethanol yield from 0.02 to 0.30 g/g, and the ethanol productivity from 0.05 to 0.57 g/(L×h). Treatment of a sugarcane bagasse hydrolysate gave similar results, and the experiments indicate that sodium borohydride is suitable for chemical in situ detoxification. The model inhibitors coniferyl aldehyde, p-benzoquinone, 2,6-dimethoxybenzoquinone, and furfural were efficiently reduced by treatment with sodium borohydride, even under mild reaction conditions (20 °C and pH 6.0). While addition of sodium dithionite to pretreatment liquid from spruce improved enzymatic hydrolysis of cellulose, addition of sodium borohydride did not. This result indicates that the strong hydrophilicity resulting from sulfonation of inhibitors by dithionite treatment was particularly important for alleviating enzyme inhibition. PMID:23567704

Cavka, Adnan; Jönsson, Leif J

2013-05-01

3

Screening of Saccharomyces cerevisiae strains with respect to anaerobic growth in non-detoxified lignocellulose hydrolysate  

DEFF Research Database (Denmark)

A microplate screening method was used to assess anaerobic growth of 12 Saccharomyces cerevisiae strains in barley straw, spruce and wheat straw hydrolysate. The assay demonstrated significant differences in inhibitor tolerance among the strains. In addition, growth inhibition by the three hydrolysates differed so that wheat hydrolysate supported growth up to 70%, while barley hydrolysate only supported growth up to 50%, with dilute-acid spruce hydrolysate taking an intermediate position. Keyword: Screening,Lignocellulose hydrolysate,Bioethanol,Yeast,Saccharomyces cerevisiae

Almeida, João Ricardo M.; Karhumaa, Kaisa

2009-01-01

4

Cultivation of lipid-producing bacteria with lignocellulosic biomass: Effects of inhibitory compounds of lignocellulosic hydrolysates.  

Science.gov (United States)

Lignocellulosic biomass has been recognized as a promising feedstock for the fermentative production of biofuel. However, the pretreatment of lignocellulose generates a number of by-products, such as furfural, 5-hydroxylmethyl furfural (5-HMF), vanillin, vanillic acids and trans-p-coumaric acid (TPCA), which are known to inhibit microbial growth. This research explores the ability of Rhodococcus opacus PD630 to use lignocellulosic biomass for production of triacylglycerols (TAGs), a common lipid raw material for biodiesel production. This study reports that R. opacus PD630 can grow well in R2A broth in the presence of these model inhibitory compounds while accumulating TAGs. Furthermore, strain PD630 can use TPCA, vanillic acid, and vanillin as carbon sources, but can only use TPCA and vanillic acid for TAG accumulation. Strain PD630 can also grow rapidly on the hydrolysates of corn stover, sorghum, and grass to accumulate TAGs, suggesting that strain PD630 is well-suited for bacterial lipid production from lignocellulosic biomass. PMID:24698742

Wang, Baixin; Rezenom, Yohannes H; Cho, Kun-Ching; Tran, Janessa L; Lee, Do Gyun; Russell, David H; Gill, Jason J; Young, Ryland; Chu, Kung-Hui

2014-06-01

5

Ethanol from lignocellulose : Alkali detoxification of dilute-acid spruce hydrolysates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Detoxification of dilute-acid lignocellulose hydrolysates by treatment with Ca(OH)2 (overliming) efficiently improves the production of fuel ethanol, but is associated with drawbacks like sugar degradation and CaSO4 precipitation. In factorial designed experiments, in which pH and temperature were varied, dilute-acid spruce hydrolysates were treated with Ca(OH)2, NH4OH or NaOH. The concentrations of sugars and inhibitory compounds were measured before and after the treatments. The fermentabil...

Alriksson, Bjo?rn

2006-01-01

6

Effect of storage conditions on the stability and fermentability of enzymatic lignocellulosic hydrolysate.  

Science.gov (United States)

To minimize the change of lignocellulosic hydrolysate composition during storage, the effects of storage conditions (temperature, pH and time) on the composition and fermentability of hydrolysate prepared from AFEX™ (Ammonia Fiber Expansion - a trademark of MBI, Lansing, MI) pretreated corn stover were investigated. Precipitates formed during hydrolysate storage increased with increasing storage pH and time. The precipitate amount was the least when hydrolysate was stored at 4 °C and pH 4.8, accounting for only 0.02% of the total hydrolysate weight after 3-month storage. No significant changes of NMR (Nuclear Magnetic Resonance) spectra and concentrations of sugars, minerals and heavy metals were observed after storage under this condition. When pH was adjusted higher before fermentation, precipitates also formed, consisting of mostly struvite (MgNH4PO4·6H2O) and brushite (CaHPO4·2H2O). Escherichia coli and Saccharomyces cerevisiae fermentation studies and yeast cell growth assays showed no significant difference in fermentability between fresh hydrolysate and stored hydrolysate. PMID:23999256

Jin, Mingjie; Bothfeld, William; Austin, Samantha; Sato, Trey K; La Reau, Alex; Li, Haibo; Foston, Marcus; Gunawan, Christa; LeDuc, Richard D; Quensen, John F; McGee, Mick; Uppugundla, Nirmal; Higbee, Alan; Ranatunga, Ruwan; Donald, Charles W; Bone, Gwen; Ragauskas, Arthur J; Tiedje, James M; Noguera, Daniel R; Dale, Bruce E; Zhang, Yaoping; Balan, Venkatesh

2013-11-01

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Fermentation of lignocellulose hydrolysates with xylose isomerases and yeasts.  

Science.gov (United States)

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 isomer...

T. Linden

1992-01-01

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Ethanol fermentation from lignocellulosic hydrolysate by a recombinant xylose- and cellooligosaccharide-assimilating yeast strain  

Energy Technology Data Exchange (ETDEWEB)

The sulfuric acid hydrolysate of lignocellulosic biomass, such as wood chips, from the forest industry is an important material for fuel bioethanol production. In this study, we constructed a recombinant yeast strain that can ferment xylose and cellooligosaccharides by integrating genes for the intercellular expressions of xylose reductase and xylitol dehydrogenase from Pichia stipitis, and xylulokinase from Saccharomyces cerevisiae and a gene for displaying ss-glucosidase from Aspergillus acleatus on the cell surface. In the fermentation of the sulfuric acid hydrolysate of wood chips, xylose and cellooligosaccharides were completely fermented after 36 h by the recombinant strain, and then about 30 g/l ethanol was produced from 73 g/l total sugar added at the beginning. In this case, the ethanol yield of this recombinant yeast was much higher than that of the control yeast. These results demonstrate that the fermentation of the lignocellulose hydrolysate is performed efficiently by the recombinant Saccharomyces strain with abilities for xylose assimilation and cellooligosaccharide degradation. (orig.)

Katahira, Satoshi; Fukuda, Hideki [Kobe Univ. (Japan). Div. of Molecular Science; Mizuike, Atsuko; Kondo, Akihiko [Kobe Univ. (Japan). Dept. of Chemical Science and Engineering

2006-10-15

9

A process for producing lignocellulosic flocs from NSSC spent liquor.  

Science.gov (United States)

Presently, the spent liquor (SL) of neutral sulfite semi chemical (NSSC) pulping process is treated in the waste water system. In this work, a new process for isolating lignocelluloses from the SL of an NSSC process is proposed and the effectiveness of this process is evaluated on industrially produced SL. The results showed that under the optimal conditions of pH 6, 30°C and 15mg/g poly ethylene imine (PEI) concentration in the SL, a maximum of 37% lignin and 37% hemicelluloses could be removed from SL. Alternatively, the dual system of poly diallyldimethyl ammonium chloride (PDADMAC) and PEI (7.5mg/g each) was evaluated in removing lignocelluloses from the SL; and the results showed that lignin and hemicellulose removals were improved to 47% and 50%, respectively. The turbidity and chemical oxygen demand (COD) of SL, as well as the elemental analysis of generated flocs were also assessed in this work. PMID:24440635

Sitter, Thomas; Oveissi, Farshad; Fatehi, Pedram

2014-03-10

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Global regulator engineering significantly improved Escherichia coli tolerances toward inhibitors of lignocellulosic hydrolysates.  

Science.gov (United States)

Lignocellulosic biomass is regarded as the most viable source of feedstock for industrial biorefinery, but the harmful inhibitors generated from the indispensable pretreatments prior to fermentation remain a daunting technical hurdle. Using an exogenous regulator, irrE, from the radiation-resistant Deinococcus radiodurans, we previously showed that a novel global regulator engineering (GRE) approach significantly enhanced tolerances of Escherichia coli to alcohol and acetate stresses. In this work, an irrE library was subjected to selection under various stresses of furfural, a typical hydrolysate inhibitor. Three furfural tolerant irrE mutants including F1-37 and F2-1 were successfully obtained. The cells containing these mutants reached OD(600) levels of 4- to 16-fold of that for the pMD18T cells in growth assay under 0.2% (v/v) furfural stress. The cells containing irrE F1-37 and F2-1 also showed considerably reduced intracellular oxygen species (ROS) levels under furfural stress. Moreover, these two irrE mutants were subsequently found to confer significant cross tolerances to two other most common inhibitors, 5-hydroxymethyl-2-furaldehyde (HMF), vanillin, as well as real lignocellulosic hydrolysates. When evaluated in Luria-Bertani (LB) medium supplemented with corn stover cellulosic hydrolysate (prepared with a solid loading of 30%), the cells containing the mutants exhibited lag phases markedly shortened by 24-44 h in comparison with the control cells. This work thus presents a promising step forward to resolve the inhibitor problem for E. coli. From the view of synthetic biology, irrE can be considered as an evolvable "part" for various stresses. Furthermore, this GRE approach can be extended to exploit other exogenous global regulators from extremophiles, and the native counterparts in E. coli, for eliciting industrially useful phenotypes. PMID:22684885

Wang, Jianqing; Zhang, Yan; Chen, Yilu; Lin, Min; Lin, Zhanglin

2012-12-01

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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

12

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

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Fermentation performance and physiology of two strains of Saccharomyces cerevisiae during growth in high gravity spruce hydrolysate and spent sulphite liquor  

Science.gov (United States)

Background Lignocellulosic materials are a diverse group of substrates that are generally scarce in nutrients, which compromises the tolerance and fermentation performance of the fermenting organism. The problem is exacerbated by harsh pre-treatment, which introduces sugars and substances inhibitory to yeast metabolism. This study compares the fermentation behaviours of two yeast strains using different types of lignocellulosic substrates; high gravity dilute acid spruce hydrolysate (SH) and spent sulphite liquor (SSL), in the absence and presence of yeast extract. To this end, the fermentation performance, energy status and fermentation capacity of the strains were measured under different growth conditions. Results Nutrient supplementation with yeast extract increased sugar uptake, cell growth and ethanol production in all tested fermentation conditions, but had little or no effect on the energy status, irrespective of media. Nutrient-supplemented medium enhanced the fermentation capacity of harvested cells, indicating that cell viability and reusability was increased by nutrient addition. Conclusions Although both substrates belong to the lignocellulosic spruce hydrolysates, their differences offer specific challenges and the overall yields and productivities largely depend on choice of fermenting strain.

2014-01-01

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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

15

A new approach on brewer's spent grains treatment and potential use as lignocellulosic yeast cells carriers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The major objective of this work is to improve the pretreatments of brewer’s spent grains (BSG) aiming at their use as a source for lignocellulosic yeast carriers (LCYC) production. Therefore, several pretreatments of BSG have been designed aiming at obtaining various yeast carriers, differing on their physicochemical composition. Cellulose, hemicellulose, lignin, fat, protein, and ash content were determined for crude BSG and the LCYCs. The long chain fatty acids profile for the crude BSG ...

Pires, Eduardo J.; Ruiz, He?ctor A.; Teixeira, J. A.; Vicente, A. A.

2012-01-01

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A New Approach on Brewer's Spent Grains Treatment and Potential Use as Lignocellulosic Yeast Cells Carriers  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The major objective of this work is to improve the pretreatments of brewer's spent grains (BSG) aiming at their use as a source for lignocellulosic yeast carriers (LCYC) production. Therefore, several pretreatments of BSG have been designed aiming at obtaining various yeast carriers, differing on their physicochemical composition. Cellulose, hemicellulose, lignin, fat, protein, and ash content were determined for crude BSG and the LCYCs. The long chain fatty acids profile for the crude BSG wa...

2012-01-01

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

18

Development of a high-throughput method to evaluate the impact of inhibitory compounds from lignocellulosic hydrolysates on the growth of Zymomonas mobilis.  

Science.gov (United States)

Overcoming the effects of hydrolysate toxicity towards ethanologens is a key technical barrier in the biochemical conversion process for biomass feedstocks to ethanol. Despite its importance, the complexity of the hydrolysate toxicity phenomena and the lack of systematic studies, analysis and tools surrounding this issue have blocked a full understanding of relationships involving toxic compounds in hydrolysates and their effects on ethanologen growth and fermentation. In this study, we developed a quantitative, high-throughput biological growth assay using an automated turbidometer to obtain detailed inhibitory kinetics for individual compounds present in lignocellulosic biomass hydrolysate. Information about prolonged lag time and final cell densities can also be obtained. The effects of furfural, hydroxymethylfurfural (HMF), acetate and ethanol on growth rate and final cell densities of Zymomonas mobilis 8b on glucose are presented. This method was also shown to be of value in toxicity studies of hydrolysate itself, despite the highly colored nature of this material. Using this approach, we can generate comprehensive inhibitory profiles with many individual compounds and develop models that predict and examine toxic effects in the complex mixture of hydrolysates, leading to the development of improved pretreatment and conditioning processes as well as fermentation organisms. PMID:19683550

Franden, Mary Ann; Pienkos, Philip T; Zhang, Min

2009-12-01

19

Butyric acid from anaerobic fermentation of lignocellulosic biomass hydrolysates by Clostridium tyrobutyricum strain RPT-4213.  

Science.gov (United States)

A novel Clostridium tyrobutyricum strain RPT-4213 was found producing butyrate under strict anaerobic conditions. This strain produced 9.47 g L(-1) butyric acid from MRS media (0.48 g/g glucose). RPT-4213 was also used to ferment dilute acid pretreated hydrolysates including wheat straw (WSH), corn fiber (CFH), corn stover (CSH), rice hull (RHH), and switchgrass (SGH). Results indicated that 50% WSH with a Clostridia medium (Ct) produced the most butyric acid (8.06 g L(-1), 0.46 g/g glucose), followed by 50% SGH with Ct (6.01 g L(-1), 0.44 g/g glucose), however, 50% CSH Ct showed growth inhibition. RPT-4213 was then used in pH-controlled bioreactor fermentations using 60% WSH and SGH, with a dilute (0.5×) Ct medium, resulting 9.87 g L(-1) butyric acid in WSH (yield 0.44 g/g) and 7.05 g L(-1) butyric acid in SGH (yield 0.42 g/g). The titer and productivity could be improved through process engineering. PMID:23811065

Liu, Siqing; Bischoff, Kenneth M; Leathers, Timothy D; Qureshi, Nasib; Rich, Joseph O; Hughes, Stephen R

2013-09-01

20

Potential uses of spent mushroom substrate and its associated lignocellulosic enzymes.  

Science.gov (United States)

Mushroom industries generate a virtually in-exhaustible supply of a co-product called spent mushroom substrate (SMS). This is the unutilised substrate and the mushroom mycelium left after harvesting of mushrooms. As the mushroom industry is steadily growing, the volume of SMS generated annually is increasing. In recent years, the mushroom industry has faced challenges in storing and disposing the SMS. The obvious solution is to explore new applications of SMS. There has been considerable discussion recently about the potentials of using SMS for production of value-added products. One of them is production of lignocellulosic enzymes such as laccase, xylanase, lignin peroxidase, cellulase and hemicellulase. This paper reviews scientific research and practical applications of SMS as a readily available and cheap source of enzymes for bioremediation, animal feed and energy feedstock. PMID:23053096

Phan, Chia-Wei; Sabaratnam, Vikineswary

2012-11-01

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

22

Inhibitory action of the toxic compounds present in lignocellulosic hydrolysates on xylose-to-xylitol bioconversion by Candida guilliermondii  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Lignocellulosic materials represent an abundant and inexpensive source of sugars which can be microbiologically converted to industrial products. However, hydrolysis of lignocellulosic materials for sugars recovery always goes together with the formation of by-products that inhibit the fermentation process. Such by-products include acetic acid, phenolic compounds such as syringaldehyde, ferulic acid, p-hydroxybenzoic acid, and vanillic acid, among others. These toxic compounds can...

Pereira, Roge?rio S.; Mussatto, Solange I.; Roberto, Ine?s Conceic?a?o

2009-01-01

23

Bioconversion of lignocellulosic fraction of water-hyacinth (Eichhornia crassipes) hemicellulose acid hydrolysate to ethanol by Pichia stipitis.  

Science.gov (United States)

Fermentation of acid hydrolysate of water-hyacinth (Eichhornia crassipes), a free floating aquatic plant has been investigated for ethanol production. The dilute acid treatment has been applied to utilize the maximum hemicellulosic content of the water-hyacinth. The goal of this work was to investigate, both experimentally and theoretically using mathematical tools, a fermentative system utilizing water-hyacinth (Eichhornia crassipes) hemicellulose acid hydrolysate as a substrate for ethanol production using Pichia stipitis. It was found that 72.83% of xylose was converted to ethanol with a yield of 0.425 g(p)/g(s) and productivity of 0.176 g(p)/L/h. An appropriate mathematical model was developed to explain theoretically the bioconversion of this hemicellulose acid hydrolysate to ethanol and the model was tested statistically to check the validity of the model. PMID:19297151

Kumar, Ashish; Singh, L K; Ghosh, Sanjoy

2009-07-01

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The chemical nature of phenolic compounds determines their toxicity and induces distinct physiological responses in Saccharomyces cerevisiae in lignocellulose hydrolysates  

Science.gov (United States)

We investigated the severity of the inhibitory effects of 13 phenolic compounds usually found in spruce hydrolysates (4-hydroxy-3-methoxycinnamaldehyde, homovanilyl alcohol, vanillin, syringic acid, vanillic acid, gallic acid, dihydroferulic acid, p-coumaric acid, hydroquinone, ferulic acid, homovanillic acid, 4-hydroxybenzoic acid and vanillylidenacetone). The effects of the selected compounds on cell growth, biomass yield and ethanol yield were studied and the toxic concentration threshold was defined for each compound. Using Ethanol Red, the popular industrial strain of Saccharomyces cerevisiae, we found the most toxic compound to be 4-hydroxy-3-methoxycinnamaldehyde which inhibited growth at a concentration of 1.8 mM. We also observed that toxicity did not generally follow a trend based on the aldehyde, acid, ketone or alcohol classification of phenolic compounds, but rather that other structural properties such as additional functional groups attached to the compound may determine its toxicity. Three distinctive growth patterns that effectively clustered all the compounds involved in the screening into three categories. We suggest that the compounds have different cellular targets, and that. We suggest that the compounds have different cellular targets and inhibitory mechanisms in the cells, also compounds who share similar pattern on cell growth may have similar inhibitory effect and mechanisms of inhibition.

2014-01-01

25

A combined adsorption and flocculation process for producing lignocellulosic complexes from spent liquors of neutral sulfite semichemical pulping process.  

Science.gov (United States)

The spent liquor (SL) of a neutral sulfite semichemical pulping process contains lignocelluloses that are currently treated in a waste water system. In this work, an adsorption process using activated carbon (AC) was considered for isolating the lignin and hemicelluloses from SL. The maximum adsorptions of 0.9g/g lignin and 0.43g/g of hemicelluloses on AC were achieved under the conditions of 30°C, pH 7 and 3h with SL/AC weight ratio of 90. The addition of polydiallyldimethylammonium chloride (PDADMAC) to the SL/AC system significantly improved the adsorption of lignin to 2.5g/g on AC. The molecular weight of PDADMAC considerably affected the results in that the higher MW PDADMAC led to less lignin, but more hemicelluloses, turbidity and chemical oxygen demand removals from the SL. The thermal analysis also revealed that the higher MW PDADMAC generated precipitates with a lower incineration temperature and heating value. PMID:24675396

Dashtban, Mehdi; Gilbert, Allan; Fatehi, Pedram

2014-05-01

26

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 a...

Sureerat Suwanapong; Naulchan Khongsay; Lakkana Laopaiboon; Prasit Jaisil; Pattana Laopaiboon

2013-01-01

27

Xylulokinase Overexpression in Two Strains of Saccharomyces cerevisiae Also Expressing Xylose Reductase and Xylitol Dehydrogenase and Its Effect on Fermentation of Xylose and Lignocellulosic Hydrolysate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Fermentation of the pentose sugar xylose to ethanol in lignocellulosic biomass would make bioethanol production economically more competitive. Saccharomyces cerevisiae, an efficient ethanol producer, can utilize xylose only when expressing the heterologous genes XYL1 (xylose reductase) and XYL2 (xylitol dehydrogenase). Xylose reductase and xylitol dehydrogenase convert xylose to its isomer xylulose. The gene XKS1 encodes the xylulose-phosphorylating enzyme xylulokinase. In this study, we dete...

Johansson, Bjo?rn; Christensson, Camilla; Hobley, Timothy; Hahn-ha?gerdal, Ba?rbel

2001-01-01

28

Monitoring on-line desalted lignocellulosic hydrolysates by microdialysis sampling micro-high performance anion exchange chromatography with integrated pulsed electrochemical detection/mass spectrometry.  

Science.gov (United States)

An on-line system based on microdialysis sampling (MD), micro-high performance anion exchange chromatography (micro-HPAEC), integrated pulsed electrochemical detection (IPED), and electrospray ionization mass spectrometry (MS) for the monitoring of on-line desalted enzymatic hydrolysates is presented. Continuous monitoring of the enzymatic degradation of dissolving pulp from Eucalyptus grandis as well as degradation of sugar cane bagasse in a 5-mL reaction vessel was achieved up to 24 h without any additional sample handling steps. Combining MD with micro-HPAEC-IPED/MS and on-line desalting of hydrolysates enabled injection (5 microL) of at least 23 samples in a study of the sequential action of hydrolytic enzymes in an unmodified environment where the enzymes and substrate were not depleted due to the perm-selectivity of the MD membrane (30 kDa cut-off). Xylanase, phenolic acid esterase and a combination of endoglucanase (EG II) with cellobiohydrolase (CBH I) resulted in the production of DP 1 after the addition of esterase, DP 2 and DP 3 after the addition of EG II and CBH I, from the dissolving pulp substrate. Similar sequential enzyme addition to sugar cane bagasse resulted in DP 1 production after the addition of esterase and DP 1, DP 2 and DP 3 production after the addition of the EG II and CBH I mixture. Combining MS on-line with micro-HPAEC-IPED proved to be a versatile and necessary tool for such a study compared to conventional methods. The mass selectivity of MS revealed complementary information, including the co-elution of saccharides as well as the presence of more than one type of DP 2 in the case of dissolving pulp and several types of DP 2 and DP 3 for sugar cane bagasse. This study demonstrates the limitation of the use of retention time alone for confirmation of the identity of saccharides especially when dealing with complex enzymatic hydrolysates. In situ sampling and sample clean-up combined with on-line desalting of the chromatographic effluent, provides a generic approach to achieve real time monitoring of enzymatic hydrolysates when they are detected by a combination of IPED and MS. PMID:12001175

Rumbold, Karl; Okatch, Harriet; Torto, Nelson; Siika-Aho, Matti; Gübitz, Georg; Robra, Karl-Heinz; Prior, Bernard

2002-06-30

29

Ethanol production from lignocellulosic materials. Fermentation and on-line analysis  

Energy Technology Data Exchange (ETDEWEB)

The fermentation performance of bacteria, yeast and fungi was investigated in lignocellulosic hydrolysates with the aim of finding microorganisms which both withstand the inhibitors and that have the ability to ferment pentoses. Firstly, the performance of Saccharomyces cidri, Saccharomyces cerevisiae, Lactobacillus brevis, Lactococcus lactis ssp lactis, Escherichia coli and Zymomonas mobilis was investigated in spent sulphite liquor and enzymatic hydrolysate of steam-pretreated willow. Secondly, the performance of natural and recombinant E. coli, Pichia stipitis, recombinant S. cerevisiae, S. cerevisiae in combination with xylose isomerase and Fusarium oxysporum was investigated in a xylose-rich acid hydrolysate of corn cob. Recombinant E. coli was the best alternative for fermentation of lignocellulosic hydrolysates, giving both high yields and productivities. The main drawback was that detoxification was necessary. The kinetics of the fermentation with recombinant E. coli KO11 was investigated in the condensate of steam-pretreated willow. A cost analysis of the ethanol production from willow was made, which predicted an ethanol production cost of 3.9 SEK/l for the pentose fermentation. The detoxification cost constituted 22% of this cost. The monitoring of three monosaccharides and ethanol in lignocellulosic hydro lysates is described. The monosaccharides were determined using immobilized pyranose oxidase in an on-line amperometric analyser. Immobilization and characterization of pyranose oxidase from Phanerochaete chrysosporium is also described. The ethanol was monitored on-line using a micro dialysis probe as an in situ sampling device. The dialysate components were then separated in a column liquid chromatographic system and the ethanol was selectively detected by an amperometric alcohol bio sensor. The determinations with on-line analysis methods agreed well with off-line methods. 248 refs, 4 figs, 12 tabs

Olsson, L.

1994-04-01

30

Bioconversion of lignocellulose: inhibitors and detoxification  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Bioconversion of lignocellulose by microbial fermentation is typically preceded by an acidic thermochemical pretreatment step designed to facilitate enzymatic hydrolysis of cellulose. Substances formed during the pretreatment of the lignocellulosic feedstock inhibit enzymatic hydrolysis as well as microbial fermentation steps. This review focuses on inhibitors from lignocellulosic feedstocks and how conditioning of slurries and hydrolysates can be used to alleviate inhibition problems. Novel developments in the area include chemical in-situ detoxification by using reducing agents, and methods that improve the performance of both enzymatic and microbial biocatalysts.

Jönsson Leif J

2013-01-01

31

Lignocellulosic feedstock resource assessment  

Energy Technology Data Exchange (ETDEWEB)

In 1997, the National Renewable Energy Laboratory (NREL) undertook a national biomass resource assessment to address a lack of basic resource information for scientists, industry, and policy-makers. The objective of this resource assessment was to describe the state-level distribution, quantity and market value of lignocellulosic feedstocks for ethanol production in the United States. Lignocellulosic feedstocks, derived from plant materials, are composed primarily of cellulose, hemicellulose, and lignin. Cellulose and hemicellulose are polymers of simple sugars that can be chemically fermented to produce ethanol. Lignin plays a role in binding cellulose and hemicellulose together in plant cell walls. This study focused on lignocellulosic by-products of agriculture, food processing, forest products industry, and consumers. The United States generates 306 million metric tons (dry weight) of lignocellulosic materials annually that could be used to manufacture ethanol. The bulk of this potential feedstock supply is made up of agricultural residues left following crop harvesting, such as corn stover. Corn stover makes up 70 percent of the total biomass resource. If agricultural residues are used for ethanol production, the price paid for agricultural residues will have to meet or exceed their current soil nutrient and animal fodder values. Food processing residues such as corn gluten feed and meal, distillers' dried grains, and spent brewer's grains are used as animal feed additives, which makes them high in cost in relation to other feedstocks. Forest products residues are mostly used for fuel, pulp, animal bedding, or mulch. The unutilized portion of these residues may be available for ethanol production. Recycled paper, sugarcane bagasse, rice straw, paper sludge, and urban tree residue show potential for use as ethanol feedstocks due to their low cost. (author)

Rooney, T.E.; Haase, S.G. [McNeil Technologies, Golden, CO (United States); Wiselogel, A.E. [National Renewable Energy Laboratory, Golden, CO (United States)

1999-07-01

32

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

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.

34

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

35

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

36

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.

2011-11-01

37

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

38

Exometabolomics Approaches in Studying the Application of Lignocellulosic Biomass as Fermentation Feedstock  

Directory of Open Access Journals (Sweden)

Full Text Available Lignocellulosic biomass is the future feedstock for the production of biofuel and bio-based chemicals. The pretreatment-hydrolysis product of biomass, so-called hydrolysate, contains not only fermentable sugars, but also compounds that inhibit its fermentability by microbes. To reduce the toxicity of hydrolysates as fermentation media, knowledge of the identity of inhibitors and their dynamics in hydrolysates need to be obtained. In the past decade, various studies have applied targeted metabolomics approaches to examine the composition of biomass hydrolysates. In these studies, analytical methods like HPLC, RP-HPLC, CE, GC-MS and LC-MS/MS were used to detect and quantify small carboxylic acids, furans and phenols. Through applying targeted metabolomics approaches, inhibitors were identified in hydrolysates and their dynamics in fermentation processes were monitored. However, to reveal the overall composition of different hydrolysates and to investigate its influence on hydrolysate fermentation performance, a non-targeted metabolomics study needs to be conducted. In this review, a non-targeted and generic metabolomics approach is introduced to explore inhibitor identification in biomass hydrolysates, and other similar metabolomics questions.

Peter J. Punt

2013-02-01

39

Conversion of acid hydrolysate of oil palm empty fruit bunch to L-lactic acid by newly isolated Bacillus coagulans JI12.  

Science.gov (United States)

Cost-effective conversion of lignocellulose hydrolysate to optically pure lactic acid is commercially attractive but very challenging. Bacillus coagulans JI12 was isolated from natural environment and used to produce L-lactic acid (optical purity?>?99.5 %) from lignocellulose sugars and acid hydrolysate of oil palm empty fruit bunch (EFB) at 50 °C and pH 6.0 without sterilization of the medium. In fed-batch fermentation with 85 g/L initial xylose and 55 g/L xylose added after 7.5 h, 137.5 g/L lactic acid was produced with a yield of 98 % and a productivity of 4.4 g/L?h. In batch fermentation of a sugar mixture containing 8.5 % xylose, 1 % glucose, and 1 % L-arabinose, the lactic acid yield and productivity reached 98 % and 4.8 g/L?h, respectively. When EFB hydrolysate was used, 59.2 g/L of lactic acid was produced within 9.5 h at a yield of 97 % and a productivity of 6.2 g/L?h, which are the highest among those ever reported from lignocellulose hydrolysates. These results indicate that B. coagulans JI12 is a promising strain for industrial production of L-lactic acid from lignocellulose hydrolysate. PMID:23504058

Ye, Lidan; Hudari, Mohammad Sufian Bin; Zhou, Xingding; Zhang, Dongxu; Li, Zhi; Wu, Jin Chuan

2013-06-01

40

Lignocellulose biodegradation : fundamentals and applications  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

 
 
 
 
41

Succinic acid production from corn cob hydrolysates by genetically engineered Corynebacterium glutamicum.  

Science.gov (United States)

Corynebacterium glutamicum wild type lacks the ability to utilize the xylose fractions of lignocellulosic hydrolysates. In the present work, we constructed a xylose metabolic pathway in C. glutamicum by heterologous expression of the xylA and xylB genes coming from Escherichia coli. Dilute-acid hydrolysates of corn cobs containing xylose and glucose were used as a substrate for succinic acid production by recombinant C. glutamicum NC-2. The results indicated that the available activated charcoal pretreatment in dilute-acid hydrolysates of corn cobs could be able to overcome the inhibitory effect in succinic acid production. Succinic acid was shown to be efficiently produced from corn cob hydrolysates (55 g l(-1) xylose and 4 g l(-1) glucose) under oxygen deprivation with addition of sodium carbonate. Succinic acid concentration reached 40.8 g l(-1) with a yield of 0.69 g g(-1) total sugars within 48 h. It was the first report of succinic acid production from corn cob hydrolysates by metabolically engineered C. glutamicum. This study suggested that dilute-acid hydrolysates of corn cobs may be an alternative substrate for the efficient production of succinic acid by C. glutamicum. PMID:24078255

Wang, Chen; Zhang, Hengli; Cai, Heng; Zhou, Zhihui; Chen, Yilu; Chen, Yali; Ouyang, Pingkai

2014-01-01

42

Mutants of the pentose-fermenting yeast Pachysolen tannophilus tolerant to hardwood spent sulfite liquor and acetic acid.  

Science.gov (United States)

A strain development program was initiated to improve the tolerance of the pentose-fermenting yeast Pachysolen tannophilus to inhibitors in lignocellulosic hydrolysates. Several rounds of UV mutagenesis followed by screening were used to select for mutants of P. tannophilus NRRL Y2460 with improved tolerance to hardwood spent sulfite liquor (HW SSL) and acetic acid in separate selection lines. The wild type (WT) strain grew in 50 % (v/v) HW SSL while third round HW SSL mutants (designated UHW301, UHW302 and UHW303) grew in 60 % (v/v) HW SSL, with two of these isolates (UHW302 and UHW303) being viable and growing, respectively, in 70 % (v/v) HW SSL. In defined liquid media containing acetic acid, the WT strain grew in 0.70 % (w/v) acetic acid, while third round acetic acid mutants (designated UAA301, UAA302 and UAA303) grew in 0.80 % (w/v) acetic acid, with one isolate (UAA302) growing in 0.90 % (w/v) acetic acid. Cross-tolerance of HW SSL-tolerant mutants to acetic acid and vice versa was observed with UHW303 able to grow in 0.90 % (w/v) acetic acid and UAA302 growing in 60 % (v/v) HW SSL. The UV-induced mutants retained the ability to ferment glucose and xylose to ethanol in defined media. These mutants of P. tannophilus are of considerable interest for bioconversion of the sugars in lignocellulosic hydrolysates to ethanol. PMID:24122119

Harner, Nicole K; Bajwa, Paramjit K; Habash, Marc B; Trevors, Jack T; Austin, Glen D; Lee, Hung

2014-01-01

43

The chemistry involved in the steam treatment of lignocellulosic materials  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Ramos, Luiz Pereira.

44

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

45

In Situ Biodiesel Production from Fast-Growing and High Oil Content Chlorella pyrenoidosa in Rice Straw Hydrolysate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Rice straw hydrolysate was used as lignocellulose-based carbon source for Chlorella pyrenoidosa cultivation and the feasibility of in situ biodiesel production was investigated. 13.7?g/L sugar was obtained by enzymatic hydrolyzation of rice straw. Chlorella pyrenoidosa showed a rapid growth in the rice straw hydrolysate medium, the maximum biomass concentration of 2.83?g/L was obtained in only 48 hours. The lipid content of the cells reached as high as 56.3%. In situ transesterification w...

Li, Penglin; Miao, Xiaoling; Li, Rongxiu; Zhong, Jianjiang

2011-01-01

46

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

47

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

48

Oleaginous fungal lipid fermentation on combined acid- and alkali-pretreated corn stover hydrolysate for advanced biofuel production.  

Science.gov (United States)

A combined hydrolysis process, which first mixed dilute acid- and alkali-pretreated corn stover at a 1:1 (w/w) ratio, directly followed by enzymatic saccharification without pH adjustment, has been developed in this study in order to minimize the need of neutralization, detoxification, and washing during the process of lignocellulosic biofuel production. The oleaginous fungus Mortierella isabellina was selected and applied to the combined hydrolysate as well as a synthetic medium to compare fungal lipid accumulation and biodiesel production in both shake flask and 7.5L fermentor. Fungal cultivation on combined hydrolysate exhibited comparable cell mass and lipid yield with those from synthetic medium, indicating that the integration of combined hydrolysis with oleaginous fungal lipid fermentation has great potential to improve performance of advanced lignocellulosic biofuel production. PMID:24768942

Ruan, Zhenhua; Zanotti, Michael; Archer, Steven; Liao, Wei; Liu, Yan

2014-07-01

49

Methods for degrading lignocellulosic materials  

Energy Technology Data Exchange (ETDEWEB)

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 fermentating microoganisms; and (c) recovering the organic substance from the fermentation.

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

2008-04-08

50

Methods for degrading lignocellulosic materials  

Energy Technology Data Exchange (ETDEWEB)

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

51

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Marton, J. M.; Felipe, M. G. A.; Silva, J. B. Almeida E.; Pessoa Ju?nior, A.

2006-01-01

52

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

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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

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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

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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

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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

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L-lactate production from seaweed hydrolysate of Laminaria japonica using metabolically engineered Escherichia coli.  

Science.gov (United States)

Renewable and carbon neutral, marine algal biomass could be an attractive alternative substrate for the production of biofuel and various biorefinery products. Thus, the feasibility of brown seaweed (Laminaria japonica) hydrolysate as a carbon source was investigated here for L-lactate production. This work reports the homofermentative route for L-lactate production by introducing Streptococcus bovis/equinus L-lactate dehydrogenase in an engineered Escherichia coli strain where synthesis of the competing by-product was blocked. The engineered strain utilized both glucose and mannitol present in the hydrolysate under microaerobic condition and produced 37.7 g/L of high optical purity L-lactate at 80 % of the maximum theoretical value. The result shown in this study implies that algal biomass would be as competitive with lignocellulosic biomass in terms of lactic acid production and that brown seaweed can be used as a feedstock for the industrial production of other chemicals. PMID:24297185

Mazumdar, Suman; Bang, Junho; Oh, Min-Kyu

2014-02-01

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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

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Trends and challenges in the microbial production of lignocellulosic bioalcohol fuels  

Energy Technology Data Exchange (ETDEWEB)

Bioalcohols produced by microorganisms from renewable materials are promising substitutes for traditional fuels derived from fossil sources. For several years already ethanol is produced in large amounts from feedstocks such as cereals or sugar cane and used as a blend for gasoline or even as a pure biofuel. However, alcohols with longer carbon chains like butanol have even more suitable properties and would better fit with the current fuel distribution infrastructure. Moreover, ethical concerns contradict the use of food and feed products as a biofuel source. Lignocellulosic biomass, especially when considered as a waste material offers an attractive alternative. However, the recalcitrance of these materials and the inability of microorganisms to efficiently ferment lignocellulosic hydrolysates still prevent the production of bioalcohols from these plentiful sources. Obviously, no known organism exist which combines all the properties necessary to be a sustainable bioalcohol producer. Therefore, breeding technologies, genetic engineering and the search for undiscovered species are promising means to provide a microorganism exhibiting high alcohol productivities and yields, converting all lignocellulosic sugars or are even able to use carbon dioxide or monoxide, and thereby being highly resistant to inhibitors and fermentation products, and easy to cultivate in huge bioreactors. In this review, we compare the properties of various microorganisms, bacteria and yeasts, as well as current research efforts to develop a reliable lignocellulosic bioalcohol producing organism. (orig.)

Weber, Christian; Farwick, Alexander; Benisch, Feline; Brat, Dawid; Dietz, Heiko; Subtil, Thorsten; Boles, Eckhard [Frankfurt Univ., Frankfurt am Main (Germany). Inst. of Molecular Biosciences

2010-07-15

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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

 
 
 
 
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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

62

Analytical determination of organic acids formed during hydrothermal and organosolv degradation of lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

The present study deals with the isotachophoretic and the ion chromatographic analysis of organic acids found in hydrolysates of lignocellulosic biomass. The samples were pretreated by means of ultrafiltration to increase the reproducibility of the measurements. The qualitative and quantitative analysis of the fractions obtained during hydrothermal and organosolv degradations of wheat straw allowed a comparison of the rate and amount of organic acids formed (formic acid, glycolic acid, lactic acid, acetic acid). Isotachophoresis facilitates research on the reaction mechanisms underlying the hydrolysis of biomass.

Bonn, G.; Bobleter, O.; Oefner, P.J.

1988-06-01

63

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

Directory of Open Access Journals (Sweden)

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

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BIOCONVERSION OF HEMICELLULOSE HYDROLYSATE OF SWEET SORGHUM BAGASSE TO ETHANOL BY USING PICHIA STIPITIS NCIM 3497 AND DEBARYOMYCES HANSENII SP.  

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Full Text Available Production of ethanol from concentrated D-xylose solutions and hemicellulose hydrolysate of sweet sorghum bagasse was achieved by using Pichia stipitis NCIM 3497 and an isolated yeast Debaryomyces hansenii sp. These yeasts were capable of producing ethanol from solutions containing 800 g/L D-xylose, and the optimum sugar concentration was found to be 150 g/L at pH 4, 30oC, with a production time of 72 hours. These yeasts were capable of utilizing multiple sugars. Hemicellulose hydrolysates of sweet sorghum bagasse were obtained by dilute acid hydrolysis and autohydrolysis including steam explosion treatment. The hydrolysate was treated by an over-liming process for detoxification and pH adjustment. Ethanol yield from hemicellulose hydrolysate was found to be higher than that of synthetic medium containing D-xylose. These yeasts can be used in production of ethanol from concentrated hemicellulose hydrolysates containing high pentose sugars obtained while treating lignocellulosic biomass at high substrate concentrations.

Jiby Kudakasseril Kurian

2010-09-01

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SO{sub 2}-ethanol-water (SEW) fractionation of lignocellulosics  

Energy Technology Data Exchange (ETDEWEB)

This study deals with SO{sub 2}-ethanol-water (SEW) fractionation as a potential method for a Lignocellulosic Biorefinery to achieve high yield separation of the three important components of biomass; cellulose, hemicelluloses and lignin. Representatives of all principal biomass species were successfully treated by SEW fractionation at similar rates. The kinetics of delignification, polysaccharides removal and cellulose hydrolysis at different temperatures and SO{sub 2} concentrations are described and interpreted from the viewpoint of acid-catalysed degradation of the biomass polymers. The fractionation pattern is compared to that of commercial acid sulfite cooking. The kinetics of delignification, hemicelluloses removal and cellulose hydrolysis during SEW fractionation each follow a two phase behaviour. The delignification is first order in lignin and SO{sub 2}. The observed lignin sulfonation and delignification patterns can be explained using Haegglund's consecutive fast sulfonation-slow hydrolysis scheme. During the initial phase of fractionation, the hemicelluloses removal and cellulose hydrolysis rates are related to the delignification rate, while in the following bulk phase the former two processes proceed independently from the latter. It is proposed that during the initial phase the hemicelluloses are removed together with lignin in the form of lignocarbohydrate complexes, while cellulose is protected by lignin from hydrolytic attack leading to a lower hydrolysis rate. Most hemicellulose side units as well as acetyl groups are cleaved during the first phase, while the glucomannan and xylan backbone polymers are removed at a considerably lower rate in the second (bulk) phase following first order kinetics in the residual polysaccharides. The observed polysaccharides dissolution behaviour can be interpreted in terms of low glucomannan stabilisation by crystallisation on cellulose at the applied conditions. Minimal cellulose dissolution occurs during fractionation, but the cellulose degree of polymerisation decreases by hydrolysis following zero-order kinetics. The products include cellulosic fibres and a spent liquor containing lignin and hydrolysed hemicellulose sugars, the latter present up to 50% in monomeric form. The investigated overall and carbohydrate material balances show no carbohydrate losses as further supported by very low amounts of formed oxidation and dehydration products. The properties of the fibre products are evaluated and their potential applications are discussed. The amount of sulfur bound to lignin is 2-3 times lower than that in acid sulfite cooking, and accounts for less than 1.1% on wood. The rest of SO{sub 2} (95-97%) can be fully recovered by distillation. (orig.)

Iakovlev, M.

2011-10-15

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Simultaneous Cellulase Production, Saccharification and Detoxification Using Dilute Acid Hydrolysate of S. spontaneum with Trichoderma reesei NCIM 992 and Aspergillus niger  

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Bioethanol production from lignocellulosic materials has several limitations. One aspect is the high production cost of cellulases used for saccharification of substrate and inhibition of fermenting yeast due to inhibitors released in acid hydrolysis. In the present work we have made an attempt to achieve simultaneous cellulases production, saccharification and detoxification using dilute acid hydrolysate of Saccharum spontaneum with and without addition of nutrients, supplemented with acid h...

Sateesh, Lanka; Rodhe, Adivikatla Vimala; Naseeruddin, Shaik; Yadav, Kothagauni Srilekha; Prasad, Yenumulagerard; Rao, Linga Venkateswar

2012-01-01

67

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

68

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

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

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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

70

Comparative study of separated fermentations and cofermentation processes to produce ethanol from hardwood derived hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

As a part of the alcoholic conversion of lignocellulosic sugars, the co-culture process was studied in continuous conditions using a medium resulting from complete hydrolysis of aspen wood and compared with the separated fermentations process performing continuously on hemicellulosic and cellulosic aspen wood derived hydrolysates. The complete conversion of mixture of glucose and xylose was obtained using a respiratory deficient mutant of Saccharomyces diastaticus cocultivated with Pichia stipitis in continuous culture. At the dilution rate of 0.125 h{sup -1}, ethanol (13.5 g 1{sup -1}) was produced with a yield of 0.25 g g{sup -1}, a volumetric productivity of 1.6 g 1{sup -1} h{sup -1} and a substrate conversion rate of 100%. In the separated fermentations scheme, ethanol (39 g 1{sup -1}) was produced by Zymomonas mobilis from cellulosic hydrolysate with a yield of 0.35 g g{sup -1} and a productivity of 7.8 g 1{sup -1} h{sup -1}, whereas Pichia stipitis grown on hemicellulosic hydrolysate produced ethanol (14 g 1{sup -1}) with a yield of 0.37 g g{sup -1} and a productivity of 0.56 g 1{sup -1} h{sup -1}. (Author)

Delgenes, J.P.; Laplace, J.M.; Moletta, R. [Institut National de la Recherche Agronomique, Narbonne (France). Lab. de Biotechnologie de l`Environnement; Navarro, J.M. [Montpellier-2 Univ., 34 (France)

1996-12-31

71

Sequential hydrolysis of waste newspaper and bioethanol production from the hydrolysate.  

Science.gov (United States)

A practical process was developed for production of a high quality hydrolysate of waste newspaper that ensured its complete fermentability to bioethanol. After pretreatment with 0.1N NaOH for 12h and sequential acid and enzyme hydrolysis, 10.1g/L of glucose (50.5%), 1.38g/L of mannose (6.9%) and 0.28g/L of galactose (1.4%), a total of 11.76g/L of fermentable sugars was obtained, which accounts for 88.7% of saccharification efficiency. The Saccharomyces cerevisiae BCRC20271 showed excellent co-fermentability of glucose, mannose and galactose in hydrolysate of waste newspaper. After cultivation of the hydrolysate at 24°C in static culture for 48h, the final ethanol concentration of 5.72g/L (96% conversion efficiency) was produced. Overall, 1000kg of waste newspaper will produce 286kg (362L) of ethanol by the process developed, which reveals that waste newspaper has higher potential than many other lignocellulosic and seaweed feedstocks for bioethanol production. PMID:24980028

Wu, Fang-Chen; Huang, Shu-Sing; Shih, Ing-Lung

2014-09-01

72

Ethanol from lignocellulose - Fermentation inhibitors, detoxification and genetic engineering of Saccharomyces cerevisiae for enhanced resistance  

Energy Technology Data Exchange (ETDEWEB)

Ethanol can be produced from lignocellulose by first hydrolysing the material to sugars, and then fermenting the hydrolysate with the yeast Saccharomyces cerevisiae. Hydrolysis using dilute sulphuric acid has advantages over other methods, however, compounds which inhibit fermentation are generated during this kind of hydrolysis. The inhibitory effect of aliphatic acids, furans, and phenolic compounds was investigated. The generation of inhibitors during hydrolysis was studied using Norway spruce as raw material. It was concluded that the decrease in the fermentability coincided with increasing harshness of the hydrolysis conditions. The decrease in fermentability was not correlated solely to the content of aliphatic acids or furan derivatives. To increase the fermentability, detoxification is often employed. Twelve detoxification methods were compared with respect to the chemical composition of the hydrolysate and the fermentability after treatment. The most efficient detoxification methods were anion-exchange at pH 10.0, overliming and enzymatic detoxification with the phenol-oxidase laccase. Detailed analyses of ion exchange revealed that anion exchange and unspecific hydrophobic interactions greatly contributed to the detoxification effect, while cation exchange did not. The comparison of detoxification methods also showed that phenolic compounds are very important fermentation inhibitors, as their selective removal with laccase had a major positive effect on the fermentability. Selected compounds; aliphatic acids, furans and phenolic compounds, were characterised with respect to their inhibitory effect on ethanolic fermentation by S. cerevisiae. When aliphatic acids or furans were compared, the inhibitory effects were found to be in the same range, but the phenolic compounds displayed widely different inhibitory effects. The possibility of genetically engineering S. cerevisiae to achieve increased inhibitor resistance was explored by heterologous expression of laccase from Trametes versicolor and by homologous overexpression of phenylacrylic acid decarboxylase. Both procedures resulted in S. cerevisiae transformants displaying increased resistance towards lignocellulose-derived aromatic compounds.

Larsson, Simona

2000-07-01

73

Harnessing genetic diversity in Saccharomyces cerevisiae for fermentation of xylose in hydrolysates of alkaline hydrogen peroxide-pretreated biomass.  

Science.gov (United States)

The fermentation of lignocellulose-derived sugars, particularly xylose, into ethanol by the yeast Saccharomyces cerevisiae is known to be inhibited by compounds produced during feedstock pretreatment. We devised a strategy that combined chemical profiling of pretreated feedstocks, high-throughput phenotyping of genetically diverse S. cerevisiae strains isolated from a range of ecological niches, and directed engineering and evolution against identified inhibitors to produce strains with improved fermentation properties. We identified and quantified for the first time the major inhibitory compounds in alkaline hydrogen peroxide (AHP)-pretreated lignocellulosic hydrolysates, including Na(+), acetate, and p-coumaric (pCA) and ferulic (FA) acids. By phenotyping these yeast strains for their abilities to grow in the presence of these AHP inhibitors, one heterozygous diploid strain tolerant to all four inhibitors was selected, engineered for xylose metabolism, and then allowed to evolve on xylose with increasing amounts of pCA and FA. After only 149 generations, one evolved isolate, GLBRCY87, exhibited faster xylose uptake rates in both laboratory media and AHP switchgrass hydrolysate than its ancestral GLBRCY73 strain and completely converted 115 g/liter of total sugars in undetoxified AHP hydrolysate into more than 40 g/liter ethanol. Strikingly, genome sequencing revealed that during the evolution from GLBRCY73, the GLBRCY87 strain acquired the conversion of heterozygous to homozygous alleles in chromosome VII and amplification of chromosome XIV. Our approach highlights that simultaneous selection on xylose and pCA or FA with a wild S. cerevisiae strain containing inherent tolerance to AHP pretreatment inhibitors has potential for rapid evolution of robust properties in lignocellulosic biofuel production. PMID:24212571

Sato, Trey K; Liu, Tongjun; Parreiras, Lucas S; Williams, Daniel L; Wohlbach, Dana J; Bice, Benjamin D; Ong, Irene M; Breuer, Rebecca J; Qin, Li; Busalacchi, Donald; Deshpande, Shweta; Daum, Chris; Gasch, Audrey P; Hodge, David B

2014-01-01

74

Improving the bioconversion yield of carbohydrates and ethanol from lignocellulosic biomass  

Science.gov (United States)

Improving the efficiency of lignocellulosic ethanol production is of the utmost importance if cellulosic bioethanol is to be competitive with fossil fuels and first generation bioethanol from starch and sucrose. Improvements in individual processes (pretreatment, saccharification, fermentation) have been ongoing, but few researchers have considered the effect that the incoming raw biomass can have on the process. It is important to understand how biomass can be altered to provide the maximum yield of hydrolysable and fermentable sugars from whatever is available. Since the moisture content is highly variable and easily altered, the effect of drying and rewetting on bioconversion was studied on switchgrass, sugarcane bagasse and hybrid poplar. For switchgrass and sugarcane bagasse, the ethanol yield after simultaneous saccharification and fermentation was improved 18-24% by increasing the moisture content by soaking prior to pretreatment. It was also found that soaking had no effect when the samples were not catalyzed with SO2 confirming that the effect of moisture content is directly related to SO2 uptake and diffusion into the biomass. In hybrid poplar, the results were similar to herbaceous biomass for chips with less than 2% absorbed SO2. However, when the SO2 uptake was increased to 3% even the air dried chips exhibited high digestibility, indicating that increased SO2 uptake can overcome the poor diffusion in dried biomass. Alongside controlling the biomass moisture content, improving knowledge and control of the processes can also increase efficiency and product yields. By monitoring reactions continuously with accurate, robust, on-line sensors, operators can detect when reactions deviate from the norm, and when they are complete. Avoiding process upsets and contamination could be the difference between an economically viable biorefinery and one that struggles to compete. Real time, continuous Raman spectroscopy was used to continuously monitor both a synthetic glucose and a lignocellulosic hydrolysate fermentation and measure glucose and ethanol. Models developed using offline HPLC validation samples had extremely high correlation between predicted and observed values for ethanol in both fermentations (R2 = 0.98 and 0.94 for synthetic and hydrolysate, respectively) while glucose proved more difficult to detect in the hydrolysate fermentation (R2 = 0.92 and 0.51). This work showed that it is possible to monitor the ethanol and glucose in a hydrolysate with a high fluorescent background.

Ewanick, Shannon M.

75

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 (H2O2) and ferrous sulfate (FeSO4) 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 0.4g/l. In contrast, treatment by 2.5mM FeSO4 and 150mM H2O2 yielded a maximum ethanol concentration of 8.3g/l. PMID:24953967

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

2014-08-01

76

Optimization study of ethanolic fermentation from oil palm trunk, rubberwood and mixed hardwood hydrolysates using Saccharomyces cerevisiae.  

Science.gov (United States)

Ethanolic fermentation using Saccharomyces cerevisiae was carried out on three types of hydrolysates produced from lignocelulosic biomass which are commonly found in Malaysia such as oil palm trunk, rubberwood and mixed hardwood. The effect of fermentation temperature and pH of hydrolysate was evaluated to optimize the fermentation efficiency which defined as maximum ethanol yield in minimum fermentation time. The fermentation process using different temperature of 25 degrees Celsius, 30 degrees Celsius and 40 degrees Celsius were performed on the prepared fermentation medium adjusted to pH 4, pH 6 and pH 7, respectively. Results showed that the fermentation time was significantly reduced with the increase of temperature but an adverse reduction in ethanol yield was observed using temperature of 40 degrees Celsius. As the pH of hydrolysate became more acidic, the ethanol yield increased. Optimum fermentation efficiency for ethanolic fermentation of lignocellulosic hydrolysates using S. cerevisiae can be obtained using 33.2 degrees Celsius and pH 5.3. PMID:20056407

Chin, K L; H'ng, P S; Wong, L J; Tey, B T; Paridah, M T

2010-05-01

77

Biocatalytic conversion of lignocellulose to platform chemicals.  

Science.gov (United States)

Naturally occurring lignocellulose can be used as a renewable resource for the sustainable production of platform chemicals that can in turn be converted to valuable fine chemicals, polymers, and fuels. The biocatalytic conversion of lignocellulose is a very promising approach due to its high selectivity, mild conditions, and low exergy loss. However, such biocatalytic processes are still seldom applied at the industrial scale since the single conversion steps (pretreatment, hydrolysis, and fermentation) may exhibit low conversion rates, low efficiencies, or high costs. The biocatalytic conversion of lignocellulose to platform chemicals is reviewed in this work. Structures and production rates of lignocellulose are described, and platform chemicals that may be produced from lignocellulose are summarized. Biocatalytic conversion of lignocellulose is distinguished from conventional non-selective approaches. All essential conversion steps used in biocatalytic approaches (pretreatment, hydrolysis, and fermentation) are reviewed in detail. Finally, potential interactions between these conversion steps are highlighted and the advantages as well as disadvantages of integrated process configurations are elucidated. In conclusion, a comprehensive understanding of the biocatalytic conversion of lignocellulose is provided in this review. PMID:22829529

Jäger, Gernot; Büchs, Jochen

2012-09-01

78

Mineralization of Detrital Lignocelluloses by Salt Marsh Sediment Microflora †  

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Specifically radiolabeled 14C-(cellulose)-lignocellulose and 14C-(lignin)-lignocellulose were isolated from labeled cuttings of Spartina alterniflora (cordgrass) and Pinus elliottii (slash pine). These were used to estimate the rates of mineralization to CO2 of lignocelluloses of estuarine and terrestrial origin in salt marsh estuarine sediments. The lignin moiety of pine lignocellulose was mineralized 10 to 14 times more slowly than that of Spartina lignocellulose, depending on the source of...

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

1980-01-01

79

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

80

Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents  

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Full Text Available Actinopyga lecanora, a type of sea cucumber commonly known as stone fish with relatively high protein content, was explored as raw material for bioactive peptides production. Six proteolytic enzymes, namely alcalase, papain, pepsin, trypsin, bromelain and flavourzyme were used to hydrolyze A. lecanora at different times and their respective degrees of hydrolysis (DH were calculated. Subsequently, antibacterial activity of the A. lecanora hydrolysates, against some common pathogenic Gram positive bacteria (Bacillus subtilis and Staphylococcus aureus and Gram negative bacteria (Escherichia coli, Pseudomonas aeruginosa, and Pseudomonas sp. were evaluated. Papain hydrolysis showed the highest DH value (89.44%, followed by alcalase hydrolysis (83.35%. Bromelain hydrolysate after one and seven hours of hydrolysis exhibited the highest antibacterial activities against Pseudomonas sp., P. aeruginosa and E. coli at 51.85%, 30.07% and 30.45%, respectively compared to the other hydrolysates. Protein hydrolysate generated by papain after 8 h hydrolysis showed maximum antibacterial activity against S. aureus at 20.19%. The potent hydrolysates were further fractionated using RP-HPLC and antibacterial activity of the collected fractions from each hydrolysate were evaluated, wherein among them only three fractions from the bromelain hydrolysates exhibited inhibitory activities against Pseudomonas sp., P. aeruginosa and E. coli at 24%, 25.5% and 27.1%, respectively and one fraction of papain hydrolysate showed antibacterial activity of 33.1% against S. aureus. The evaluation of the relationship between DH and antibacterial activities of papain and bromelain hydrolysates revealed a meaningful correlation of four and six order functions.

Raheleh Ghanbari

2012-12-01

 
 
 
 
81

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

82

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)

2013-01-01

83

Membrane extraction for detoxification of biomass hydrolysates.  

Science.gov (United States)

Membrane extraction was used for the removal of sulfuric acid, acetic acid, 5-hydroxymethyl furfural and furfural from corn stover hydrolyzed with dilute sulfuric acid. Microporous polypropylene hollow fiber membranes were used. The organic extractant consisted of 15% Alamine 336 in: octanol, a 50:50 mixture of oleyl alcohol:octanol or oleyl alcohol. Rapid removal of sulfuric acid, 5-hydroxymethyl and furfural was observed. The rate of acetic acid removal decreased as the pH of the hydrolysate increased. Regeneration of the organic extractant was achieved by back extraction into an aqueous phase containing NaOH and ethanol. A cleaning protocol consisting of flushing the hydrolysate compartment with NaOH and the organic phase compartment with pure organic phase enabled regeneration and reuse of the module. Ethanol yields from hydrolysates detoxified by membrane extraction using 15% Alamine 336 in oleyl alcohol were about 10% higher than those from hydrolysates detoxified using ammonium hydroxide treatment. PMID:22361069

Grzenia, David L; Schell, Daniel J; Wickramasinghe, S Ranil

2012-05-01

84

Membrane Extraction for Detoxification of Biomass Hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

Membrane extraction was used for the removal of sulfuric acid, acetic acid, 5-hydroxymethyl furfural and furfural from corn stover hydrolyzed with dilute sulfuric acid. Microporous polypropylene hollow fiber membranes were used. The organic extractant consisted of 15% Alamine 336 in: octanol, a 50:50 mixture of oleyl alcohol:octanol or oleyl alcohol. Rapid removal of sulfuric acid, 5-hydroxymethyl and furfural was observed. The rate of acetic acid removal decreased as the pH of the hydrolysate increased. Regeneration of the organic extractant was achieved by back extraction into an aqueous phase containing NaOH and ethanol. A cleaning protocol consisting of flushing the hydrolysate compartment with NaOH and the organic phase compartment with pure organic phase enabled regeneration and reuse of the module. Ethanol yields from hydrolysates detoxified by membrane extraction using 15% Alamine 336 in oleyl alcohol were about 10% higher than those from hydrolysates detoxified using ammonium hydroxide treatment.

Grzenia, D. L.; Schell, D. J.; Wickramasinghe, S. R.

2012-05-01

85

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.

86

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

87

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

88

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

89

Prebiotic xylo-oligosaccharides as high-value co-products on an integrated biorefinery approach from lignocellulosic feedstock  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The present work proposes the production of prebiotic xylo-oligosaccharides (XOS) as high-value co-products of the Lignocellulose Feedstock Biorefinery concept, foreseeing potential applications on food, feed and nutraceutical industries. Autohydrolysis was used to selectively solubilise the hemicellulosic fraction of several xylan-rich, widely available, agricultural, agro-industrial and forestry by-products: corn cobs, brewery’s spent grain and Eucalyptus wood chips. The soluble hemicellu...

Moura, Patri?cia; Carvalheiro, Florbela; Esteves, M. P.; Gi?rio, Francisco M.

2008-01-01

90

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.

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

91

Ethanol production with dilute acid hydrolysis using partially dried lignocellulosics  

Energy Technology Data Exchange (ETDEWEB)

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

92

Evaluation of oat hull hemicellulosic hydrolysate fermentability employing Pichia stipitis  

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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 untreated 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 ...

2012-01-01

93

Peat Hydrolysate Medium Optimization for Pullulan Production  

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Peat hydrolysate, a diluted acid-autoclaved extract of peat, was used as a substrate for the production of the extracellular polysaccharide pullulan by three strains of Aureobasidium pullulans, 140B, 142, and 2552. It was found that the addition of (NH4)2SO4 and K2HPO4 as sources of nitrogen and phosphate, respectively, is not necessary for the polysaccharide production. The economically optimized culture medium for large-scale production of pullulan contains peat hydrolysate, 0.05% NaCl, 0.0...

1984-01-01

94

Biochemical and functional characterisation of casein and whey protein hydrolysates.  

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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

95

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

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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 am...

Silva, Maria Elisabeth Machado Pinto E.; Ive Paton; Marlene Trigo; Von Atzingen, Maria Carolina B. C.; Kira, Carmem S.; Inomata, Emiko I.; Lamardo, Leda C. A.

2008-01-01

96

Ethanol Production from Wet-Exploded Wheat Straw Hydrolysate by Thermophilic Anaerobic Bacterium Thermoanaerobacter BG1L1 in a Continuous Immobilized Reactor  

Science.gov (United States)

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 70°C. Undetoxified wheat straw hydrolysate was used (3-12% dry matter), corresponding to sugar mixtures of glucose and xylose ranging from 12 to 41 g/1. The organism, thermophilic anaerobic bacterium Thermoanaerobacter BG1L1, exhibited significant resistance to high levels of acetic acid (up to 10 g/1) 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 J.; Ahring, Birgitte K.

97

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

98

Recent Developments in the Bioconversion of Lignocelluloses into Ethanol  

Directory of Open Access Journals (Sweden)

Full Text Available 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 lignocellulose biomass is a complex mixture of carbohydrate polymers. In order to develop an efficient process, there have been many attempts to obtain more efficient ways in the conversion of lignocelluloses to ethanol, including pretreatment, enzymatic hydrolysis of lignocelluloses and direct co-culture fermentation. This paper describes the production process of ethanol from starch-containing material, recent developments on the enzymatic bioconversion of lignocelluloses into sugars and their subsequent fermentation into ethanol and the possible recombination of microbes for the direct conversion of lignocelluloses into ethanol.

KOESNANDAR

2008-12-01

99

Complex xylo-oligosaccharides identified from hydrothermally treated Eucalyptus wood and brewery's spent grain.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Hydrolysates from two hydrothermally treated xylan-rich agrobased materials, Eucalyptus wood and brewery's spent grain were fractionated by anion-exchange chromatography and size-exclusion chromatography. Hereby, several pools were obtained and they were characterised by their sugar composition. Additionally, the oligosaccharides in the pools described were further identified by high-performance anion-exchange chromatography and mass spectrometry. The hydrothermally treated brewery's spent gr...

2002-01-01

100

Method of stabilizing wood or lignocellulose materials  

International Nuclear Information System (INIS)

Wood or lignocellulose materials are impregnated with vinyl or allyl monomers and unsaturated polyester resins or with modified epoxy, alkyd or polyurethane resins in a mixture. The mixture contains chemical initiators of polymerization - organic peroxides or peroxyesters in an amount of 3 % max. Polymerization is effected by ionizing radiation. (B.S.)

1973-01-01

 
 
 
 
101

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

102

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

Marton, J. M.; Felipe, M. G. A.; Almeida e Silva, J. B.; Pessoa Júnior, A..

103

Direct glucose production from lignocellulose using Clostridium thermocellum cultures supplemented with a thermostable ?-glucosidase  

Science.gov (United States)

Background Cellulases continue to be one of the major costs associated with the lignocellulose hydrolysis process. Clostridium thermocellum is an anaerobic, thermophilic, cellulolytic bacterium that produces cellulosomes capable of efficiently degrading plant cell walls. The end-product cellobiose, however, inhibits degradation. To maximize the cellulolytic ability of C. thermocellum, it is important to eliminate this end-product inhibition. Results This work describes a system for biological saccharification that leads to glucose production following hydrolysis of lignocellulosic biomass. C. thermocellum cultures supplemented with thermostable beta-glucosidases make up this system. This approach does not require any supplementation with cellulases and hemicellulases. When C. thermocellum strain S14 was cultured with a Thermoanaerobacter brockii beta-glucosidase (CglT with activity 30 U/g cellulose) in medium containing 100 g/L cellulose (617 mM initial glucose equivalents), we observed not only high degradation of cellulose, but also accumulation of 426 mM glucose in the culture broth. In contrast, cultures without CglT, or with less thermostable beta-glucosidases, did not efficiently hydrolyze cellulose and accumulated high levels of glucose. Glucose production required a cellulose load of over 10 g/L. When alkali-pretreated rice straw containing 100 g/L glucan was used as the lignocellulosic biomass, approximately 72% of the glucan was saccharified, and glucose accumulated to 446 mM in the culture broth. The hydrolysate slurry containing glucose was directly fermented to 694 mM ethanol by addition of Saccharomyces cerevisiae, giving an 85% theoretical yield without any inhibition. Conclusions Our process is the first instance of biological saccharification with exclusive production and accumulation of glucose from lignocellulosic biomass. The key to its success was the use of C. thermocellum supplemented with a thermostable beta-glucosidase and cultured under a high cellulose load. We named this approach biological simultaneous enzyme production and saccharification (BSES). BSES may resolve a significant barrier to economical production by providing a platform for production of fermentable sugars with reduced enzyme amounts.

2013-01-01

104

40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...  

Science.gov (United States)

...Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement...Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the...Extract Hydrolysate from Saccharomyces cerevisiae on all food...

2010-07-01

105

Hydrogen Production from Paper Sludge Hydrolysate  

DEFF Research Database (Denmark)

The main objective of this study was to develop a system for the production of â??renewableâ? hydrogen. Paper sludge is a solid industrial waste yielding mainly cellulose, which can be used, after hydrolysis, as a feedstock in anaerobic fermentation by (hyper)thermophilic organisms, such as Thermotoga elfii and Caldicellulosiruptor saccharolyticus. Tests on different medium compositions showed that both bacteria were able to produce hydrogen from paper sludge hydrolysate, but the amount of produced hydrogen and the requirement for other components differed. Hydrogen production by T. elfii strongly depended on the presence of yeast extract and salts. By contrast, C. saccharolyticus was less dependent on medium components but seemed to be inhibited by a component present in the sludge hydrolysate. Utilization of xylose was preferred over glucose by C. saccharolyticus.

Kádár, Zsófia; de Vrije, Truus

2003-01-01

106

Hydrogen production from paper sludge hydrolysate  

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The main objective of this study was to develop a system for the production of 'renewable' hydrogen. Paper sludge is a solid industrial waste yielding mainly cellulose, which can be used, after hydrolysis, as a feedstock in anaerobic fermentation by (hyper)thermophilic organisms, such as Thermotoga elfii and Caldicellulosiruptor saccharolyticus. Tests on different medium compositions showed that both bacteria were able to produce hydrogen from paper sludge hydrolysate, but the amount of produ...

Ka?da?r, Z.; Vrije, G. J.; Budde, M. A. W.; Szengyel, Z.; Reczey, K.; Claassen, P. A. M.

2003-01-01

107

Symbiotic digestion of lignocellulose in termite guts.  

Science.gov (United States)

Their ability to degrade lignocellulose gives termites an important place in the carbon cycle. This ability relies on their partnership with a diverse community of bacterial, archaeal and eukaryotic gut symbionts, which break down the plant fibre and ferment the products to acetate and variable amounts of methane, with hydrogen as a central intermediate. In addition, termites rely on the biosynthetic capacities of their gut microbiota as a nutritional resource. The mineralization of humus components in the guts of soil-feeding species also contributes to nitrogen cycling in tropical soils. Lastly, the high efficiency of their minute intestinal bioreactors makes termites promising models for the industrial conversion of lignocellulose into microbial products and the production of biofuels. PMID:24487819

Brune, Andreas

2014-03-01

108

GENETICALLY MODIFIED LIGNOCELLULOSIC BIOMASS FOR IMPROVEMENT OF ETHANOL PRODUCTION  

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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 i...

2010-01-01

109

Ionic liquid pretreatment of lignocellulosic biomass  

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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

110

Conversion of Lignocellulosic Material into Fermentable Sugars  

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Lignocellulosic biomass to biofuel conversion is a promising technology to provide a unique and sustainable resource for environmentally safe organic fuels and chemicals. Most of global energy use projections predict that biomass will be a more important component of primary energy supply in the future, and that woody crops will be the primary source of biomass. Short-rotation willow wood crops (Salix sp.) are considered a promising source of bioenergy, willow wood has several characteristics...

Mohammed, Asem Hassan

2012-01-01

111

Evaluation of oat hull hemicellulosic hydrolysate fermentability employing Pichia stipitis  

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Full Text Available 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 untreated 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

2012-10-01

112

The road to commercial lignocellulosic ethanol  

Energy Technology Data Exchange (ETDEWEB)

The transportation sector is the second largest energy user and the largest oil user. It has been estimated that by 2050, there will be 2.3 billion additional cars worldwide, of which 1.9 billion will be in developing countries. Global ethanol production is set to grow 12-fold between 2006 and 2030. Novozymes is a world leader in industrial enzymes and microorganisms. This presentation highlighted their commitment to the ethanol industry, with particular reference to its expertise in starch-based ethanol enzymes. The company works on various feedstocks and technologies with different partners in the United States, China, Brazil and Europe in order to enable the ethanol industry to commercialize lignocellulosic ethanol through cost efficient bioconversion. Novozymes processes are developed and integrated to make sustainable lignocellulosic ethanol production competitive with gasoline in the near term. Examples of Novozymes work on enzyme improvements were presented along with process developments. Full cost modeling demonstrated how these developments help bring down the cost of lignocellulosic ethanol to a cost competitive level. tabs., figs.

Fuglsang, C.C. [Novozymes Inc., Davis, CA (United States); Smith, M.T. [Novozymes North America, Franklinton, NC (United States); Mogensen, J. [Novozymes A/S, Bagsvaerd (Denmark); Lauridsen, C. [Novozymes China, Beijing (China)

2009-07-01

113

Fungal Bioconversion of Lignocellulosic Residues; Opportunities & Perspectives  

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Full Text Available The development of alternative energy technology is critically important because of the rising prices of crude oil, security issues regarding the oil supply, and environmental issues such as global warming and air pollution. Bioconversion of biomass has significant advantages over other alternative energy strategies because biomass is the most abundant and also the most renewable biomaterial on our planet. Bioconversion of lignocellulosic residues is initiated primarily by microorganisms such as fungi and bacteria which are capable of degrading lignocellulolytic materials. Fungi such as Trichoderma reesei and Aspergillus niger produce large amounts of extracellular cellulolytic enzymes, whereas bacterial and a few anaerobic fungal strains mostly produce cellulolytic enzymes in a complex called cellulosome, which is associated with the cell wall. In filamentous fungi, cellulolytic enzymes including endoglucanases, cellobiohydrolases (exoglucanases and ?-glucosidases work efficiently on cellulolytic residues in a synergistic manner. In addition to cellulolytic/hemicellulolytic activities, higher fungi such as basidiomycetes (e.g. Phanerochaete chrysosporium have unique oxidative systems which together with ligninolytic enzymes are responsible for lignocellulose degradation. This review gives an overview of different fungal lignocellulolytic enzymatic systems including extracellular and cellulosome-associated in aerobic and anaerobic fungi, respectively. In addition, oxidative lignocellulose-degradation mechanisms of higher fungi are discussed. Moreover, this paper reviews the current status of the technology for bioconversion of biomass by fungi, with focus on mutagenesis, co-culturing and heterologous gene expression attempts to improve fungal lignocellulolytic activities to create robust fungal strains.

Mehdi Dashtban, Heidi Schraft, Wensheng Qin

2009-01-01

114

PROTEIN HYDROLYSATES IN SPORTS AND EXERCISE: A BRIEF REVIEW  

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Full Text Available Protein can be hydrolyzed, producing small chains of amino acids called peptides. Several studies have shown that protein hydrolysates containing mostly di- and tripeptides are absorbed more rapidly than free form amino acids and much more rapidly than intact proteins. In addition, there is recent evidence that protein hydrolysate ingestion has strong insulinotropic effect. Thus, recovery sports drinks containing protein hydrolysates may be of great value

Anssi H. Manninen

2004-06-01

115

Comparison of Yeast Growth in Mesquite Wood Hydrolysate  

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Hot-water extracts of mesquite (Prosopis glandulosa) wood were assayed for their total carbohydrate, reducing sugar, and glucose content. These hydrolysates were then used as complete media for yeast growth. A total of 10 strains of yeasts were evaluated for their biomass production in the mesquite wood hydrolysates. Levels of utilizable carbohydrate proved to be the limiting factor for yeast growth in the hydrolysates.

Stanlake, Gary J.

1986-01-01

116

Hydrolysis and fractionation of lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

A multi-function process is described for the hydrolysis and fractionation of lignocellulosic biomass to separate hemicellulosic sugars from other biomass components such as extractives and proteins; a portion of the solubilized lignin; cellulose; glucose derived from cellulose; and insoluble lignin from said biomass comprising one or more of the following: optionally, as function 1, introducing a dilute acid of pH 1.0--5.0 into a continual shrinking bed reactor containing a lignocellulosic biomass material at a temperature of about 94 to about 160 C for a period of about 10 to about 120 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of extractives, lignin, and protein by keeping the solid to liquid ratio constant throughout the solubilization process; as function 2, introducing a dilute acid of pH 1.0--5.0, either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing either fresh biomass or the partially fractionated lignocellulosic biomass material from function 1 at a temperature of about 94--220 C for a period of about 10 to about 60 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of hemicellulosic sugars, semisoluble sugars and other compounds, and amorphous glucans by keeping the solid to liquid ratio constant throughout the solubilization process; as function 3, optionally, introducing a dilute acid of pH 1.0--5.0 either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing the partially fractionated lignocellulosic biomass material from function 2 at a temperature of about 180--280 C for a period of about 10 to about 60 minutes at a volumetric flow rate of 1 to about 5 reactor volumes to effect solubilization of cellulosic sugars by keeping the solid to liquid ratio constant throughout the solubilization process; and as function 4, optionally, introducing a dilute acid of pH 1.0--5.0 either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing the partially fractionated lignocellulosic biomass material from function 3 at a temperature of about 180--280 C for a period of about 10 to about 60 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of cellulosic sugars by keeping the solid to liquid ratio constant throughout the solubilization process.

Torget, R.W.; Padukone, N.; Hatzis, C.; Wyman, C.E.

2000-02-08

117

Hydrolysis and fractionation of lignocellulosic biomass  

Science.gov (United States)

A multi-function process is described for the hydrolysis and fractionation of lignocellulosic biomass to separate hemicellulosic sugars from other biomass components such as extractives and proteins; a portion of the solubilized lignin; cellulose; glucose derived from cellulose; and insoluble lignin from said biomass comprising one or more of the following: optionally, as function 1, introducing a dilute acid of pH 1.0-5.0 into a continual shrinking bed reactor containing a lignocellulosic biomass material at a temperature of about 94 to about 160.degree. C. for a period of about 10 to about 120 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of extractives, lignin, and protein by keeping the solid to liquid ratio constant throughout the solubilization process; as function 2, introducing a dilute acid of pH 1.0-5.0, either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing either fresh biomass or the partially fractionated lignocellulosic biomass material from function 1 at a temperature of about 94-220.degree. C. for a period of about 10 to about 60 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of hemicellulosic sugars, semisoluble sugars and other compounds, and amorphous glucans by keeping the solid to liquid ratio constant throughout the solubilization process; as function 3, optionally, introducing a dilute acid of pH 1.0-5.0 either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing the partially fractionated lignocellulosic biomass material from function 2 at a temperature of about 180-280.degree. C. for a period of about 10 to about 60 minutes at a volumetric flow rate of 1 to about 5 reactor volumes to effect solubilization of cellulosic sugars by keeping the solid to liquid ratio constant throughout the solubilization process; and as function 4, optionally, introducing a dilute acid of pH 1.0-5.0 either as virgin acid or an acidic stream from another function, into a continual shrinking bed reactor containing the partially fractionated lignocellulosic biomass material from function 3 at a temperature of about 180-280.degree. C. for a period of about 10 to about 60 minutes at a volumetric flow rate of about 1 to about 5 reactor volumes to effect solubilization of cellulosic sugars by keeping the solid to liquid ratio constant throughout the solubilization process.

Torget, Robert W. (Littleton, CO) [Littleton, CO; Padukone, Nandan (Denver, CO) [Denver, CO; Hatzis, Christos (Denver, CO) [Denver, CO; Wyman, Charles E. (Lakewood, CO) [Lakewood, CO

2000-01-01

118

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

119

[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

120

Method of stabilizing wood or lignocellulose materials  

International Nuclear Information System (INIS)

Stabilization is effected by impregnating wood or lignocellulose materials with unsaturated monomers in a solution of organic solvents in the presence of swelling agents containing at least one organic halo compound with halogen content exceeding 30 wt. % and not exce--eding the amount corresponding to a saturated solution in the impregnation mixture. Polymerization is effected by ionizing radiation and is completed by the action of temperature in a range of 40 to 150 degC; at the same time, the solvents and the swelling agents should be removed. (B.S.)

1973-01-01

 
 
 
 
121

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

122

Antioxidant activities of chick embryo egg hydrolysates.  

Science.gov (United States)

Chick embryo egg hydrolysates (CEEH) were obtained by enzymatic hydrolysis of chick embryo egg in vitro-simulated gastrointestinal digestion. The antioxidant activities of CEEH were investigated by employing three in vitro assays, including the 2,2'-azinobis-(3-ethylbenzthiazoline-6-sulfonate)/1,1-diphenyl-2-picrylhydrazyl (ABTS/DPPH)/hydroxyl radical-scavenging assays. The radical-scavenging effect of CEEH (1.0?mg/mL) was in a dose-dependent manner, with the highest trolox equivalent antioxidant capacity for ABTS, DPPH, and that of hydroxyl radicals found to be 569, 2097, and 259.6??mol/L, respectively; whereas the trolox equivalent antioxidant capacity of unhatched egg for ABTS, DPPH, and that of hydroxyl radicals were found to be 199, 993, and 226.5??mol/L, respectively. CEEH showed stronger scavenging activity than the hydrolysates of unhatched egg against free radicals such as ABTS, DPPH, and hydroxyl radicals. The antioxidant amino acid analysis indicated that the 14-day CEEH possess more antioxidant amino acids than that of the unhatched egg. In addition, essential amino acids analysis showed that the 14-day CEEH have the highest nutritional value. Combined with the results of the amino acid profiles, CEEH were believed to have higher nutritive value in addition to antioxidant activities than the unhatched egg. PMID:24804065

Sun, Hao; Ye, Ting; Wang, Yuntao; Wang, Ling; Chen, Yijie; Li, Bin

2014-01-01

123

Antioxidant activities of chick embryo egg hydrolysates  

Science.gov (United States)

Chick embryo egg hydrolysates (CEEH) were obtained by enzymatic hydrolysis of chick embryo egg in vitro-simulated gastrointestinal digestion. The antioxidant activities of CEEH were investigated by employing three in vitro assays, including the 2,2?-azinobis-(3-ethylbenzthiazoline-6-sulfonate)/1,1-diphenyl-2-picrylhydrazyl (ABTS/DPPH)/hydroxyl radical-scavenging assays. The radical-scavenging effect of CEEH (1.0?mg/mL) was in a dose-dependent manner, with the highest trolox equivalent antioxidant capacity for ABTS, DPPH, and that of hydroxyl radicals found to be 569, 2097, and 259.6??mol/L, respectively; whereas the trolox equivalent antioxidant capacity of unhatched egg for ABTS, DPPH, and that of hydroxyl radicals were found to be 199, 993, and 226.5??mol/L, respectively. CEEH showed stronger scavenging activity than the hydrolysates of unhatched egg against free radicals such as ABTS, DPPH, and hydroxyl radicals. The antioxidant amino acid analysis indicated that the 14-day CEEH possess more antioxidant amino acids than that of the unhatched egg. In addition, essential amino acids analysis showed that the 14-day CEEH have the highest nutritional value. Combined with the results of the amino acid profiles, CEEH were believed to have higher nutritive value in addition to antioxidant activities than the unhatched egg.

Sun, Hao; Ye, Ting; Wang, Yuntao; Wang, Ling; Chen, Yijie; Li, Bin

2014-01-01

124

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

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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 b [...] y 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.

Pinto e Silva, Maria Elisabeth Machado; Paton, Ive; Trigo, Marlene; von Atzingen, Maria Carolina B. C.; Kira, Carmem S.; Inomata, Emiko I.; Lamardo, Leda C. A..

125

Degradation of extractive-free lignocelluloses by Coriolus versicolor and Poria placenta  

Energy Technology Data Exchange (ETDEWEB)

The wood-decay fungi Coriolus versicolor, a white-rot fungus, and Poria placenta, a brown-rot fungus, were grown on an extractive-free lignocellulose prepared from quackgrass (Agropyron repens). Their abilities to decompose this lignocellulose were compared to their abilities to decompose softwood (Picea pungens) and hardwood (Acer rubrum) lignocelluloses. The two fungi were grown on malt-extract dampened lignocelluloses at 28 degrees C for up to 12 weeks. Replicate cultures were periodically harvested and lignocellulose decomposition was followed by monitoring substrate weight loss, lignin loss, and carbohydrate loss. Coriolus versicolor decomposed the lignin and carbohydrate components of the grass lignocellulose as efficiently as the softwood and hardwood lignocelluloses. Poria placenta, however, was not an efficient degrader of either lignin or carbohydrate in the grass lignocellulose. Poria placenta readily decomposed carbohydrate components of the softwood lignocellulose but not the hardwood lignocellulose. (Refs. 17).

Antai, S.P.; Crawford, D.L.

1982-04-01

126

Mineralization of detrital lignocelluloses by salt marsh sediment microflora.  

Science.gov (United States)

Specifically radiolabeled C-(cellulose)-lignocellulose and C-(lignin)-lignocellulose were isolated from labeled cuttings of Spartina alterniflora (cordgrass) and Pinus elliottii (slash pine). These were used to estimate the rates of mineralization to CO(2) of lignocelluloses of estuarine and terrestrial origin in salt marsh estuarine sediments. The lignin moiety of pine lignocellulose was mineralized 10 to 14 times more slowly than that of Spartina lignocellulose, depending on the source of inoculum. Average values for percent mineralization after 835 h of incubation were 1.4 and 13.9%, respectively. For Spartina lignocellulose, mineralization of the cellulose moiety was three times faster than that of the lignin moiety. Average values for percent mineralization after 720 h of incubation were 32.1 and 10.6%, respectively. Lignocellulose and lignin contents of live pine and Spartina plants were analyzed and found to be 60.7 and 20.9%, respectively, for pine and 75.6 and 15.1%, respectively, for Spartina. PMID:16345647

Maccubbin, A E; Hodson, R E

1980-10-01

127

Metabolic engineering of Saccharomyces cerevisiae for increased bioconversion of lignocellulose to ethanol.  

Science.gov (United States)

The absence of pentose-utilizing enzymes in Saccharomyces cerevisiae is an obstacle for efficiently converting lignocellulosic materials to ethanol. In the present study, the genes coding xylose reductase (XYL1) and xylitol dehydrogenase (XYL2) from Pichia stipitis were successfully engineered into S. cerevisae. As compared to the control transformant, engineering of XYL1 and XYL2 into yeasts significantly increased the microbial biomass (8.1 vs. 3.4 g/L), xylose consumption rate (0.15 vs. 0.02 g/h) and ethanol yield (6.8 vs. 3.5 g/L) after 72 h fermentation using a xylose-based medium. Interestingly, engineering of XYL1 and XYL2 into yeasts also elevated the ethanol yield from sugarcane bagasse hydrolysate (SUBH). This study not only provides an effective approach to increase the xylose utilization by yeasts, but the results also suggest that production of ethanol by this recombinant yeasts using unconventional nutrient sources, such as components in SUBH deserves further attention in the future. PMID:23997337

Jun, He; Jiayi, Cai

2012-09-01

128

Encapsulation-Induced Stress Helps Saccharomyces cerevisiae Resist Convertible Lignocellulose Derived Inhibitors  

Directory of Open Access Journals (Sweden)

Full Text Available The ability of macroencapsulated Saccharomyces cerevisiae CBS8066 to withstand readily and not readily in situ convertible lignocellulose-derived inhibitors was investigated in anaerobic batch cultivations. It was shown that encapsulation increased the tolerance against readily convertible furan aldehyde inhibitors and to dilute acid spruce hydrolysate, but not to organic acid inhibitors that cannot be metabolized anaerobically. Gene expression analysis showed that the protective effect arising from the encapsulation is evident also on the transcriptome level, as the expression of the stress-related genes YAP1, ATR1 and FLR1 was induced upon encapsulation. The transcript levels were increased due to encapsulation already in the medium without added inhibitors, indicating that the cells sensed low stress level arising from the encapsulation itself. We present a model, where the stress response is induced by nutrient limitation, that this helps the cells to cope with the increased stress added by a toxic medium, and that superficial cells in the capsules degrade convertible inhibitors, alleviating the inhibition for the cells deeper in the capsule.

Johan O. Westman

2012-09-01

129

Engineering furfural tolerance in Escherichia coli improves the fermentation of lignocellulosic sugars into renewable chemicals.  

Science.gov (United States)

Pretreatments such as dilute acid at elevated temperature are effective for the hydrolysis of pentose polymers in hemicellulose and also increase the access of enzymes to cellulose fibers. However, the fermentation of resulting syrups is hindered by minor reaction products such as furfural from pentose dehydration. To mitigate this problem, four genetic traits have been identified that increase furfural tolerance in ethanol-producing Escherichia coli LY180 (strain W derivative): increased expression of fucO, ucpA, or pntAB and deletion of yqhD. Plasmids and integrated strains were used to characterize epistatic interactions among traits and to identify the most effective combinations. Furfural resistance traits were subsequently integrated into the chromosome of LY180 to construct strain XW129 (LY180 ?yqhD ackA::PyadC'fucO-ucpA) for ethanol. This same combination of traits was also constructed in succinate biocatalysts (Escherichia coli strain C derivatives) and found to increase furfural tolerance. Strains engineered for resistance to furfural were also more resistant to the mixture of inhibitors in hemicellulose hydrolysates, confirming the importance of furfural as an inhibitory component. With resistant biocatalysts, product yields (ethanol and succinate) from hemicellulose syrups were equal to control fermentations in laboratory media without inhibitors. The combination of genetic traits identified for the production of ethanol (strain W derivative) and succinate (strain C derivative) may prove useful for other renewable chemicals from lignocellulosic sugars. PMID:23431191

Wang, Xuan; Yomano, Lorraine P; Lee, James Y; York, Sean W; Zheng, Huabao; Mullinnix, Michael T; Shanmugam, K T; Ingram, Lonnie O

2013-03-01

130

In vitro iron absorption of ?-lactalbumin hydrolysate-iron and ?-lactoglobulin hydrolysate-iron complexes.  

Science.gov (United States)

To study the feasibility of promoting iron absorption by peptides derived from ?-lactalbumin and ?-lactoglobulin, the present work examined the transport of iron across Caco-2 monolayer cell as in vitro model. Caco-2 cells were seeded in bicameral chambers with ?-lactalbumin hydrolysate-Fe (?-LAH-Fe) complex and ?-lactoglobulin hydrolysate-Fe (?-LGH-Fe) complex, ?-LAH and iron mixture, ?-LGH and iron mixture, FeSO4 and ascorbic acid mixture, and FeSO4. In addition, the cytotoxicity of ?-LAH-Fe and ?-LGH-Fe complexes were measured by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The iron absorption and ferritin content were assessed using the coupled in vitro digestion/Caco-2 cell model. Results support that peptide-iron complexes can promote ferritin formation and it is possible to apply ?-LGH-Fe complexes as iron-fortified supplements with high iron absorbability. PMID:24612808

Wang, X; Ai, T; Meng, X L; Zhou, J; Mao, X Y

2014-05-01

131

Pichia stipitis xylose reductase helps detoxifying lignocellulosic hydrolysate by reducing 5-hydroxymethyl-furfural (HMF)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background Pichia stipitis xylose reductase (Ps-XR) has been used to design Saccharomyces cerevisiae strains that are able to ferment xylose. One example is the industrial S. cerevisiae xylose-consuming strain TMB3400, which was constructed by expression of P. stipitis xylose reductase and xylitol dehydrogenase and overexpression of endogenous xylulose kinase in the industrial S. cerevisiae strain USM21. Results...

2008-01-01

132

A novel fermentation strategy for removing the key inhibitor acetic acid and efficiently utilizing the mixed sugars from lignocellulosic hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

As part of preliminary research efforts, we have completed several experiments which demonstrate 'proof of concept.' These experiments addressed the following three questions: (1) Can a synthetic mixed sugar solution of glucose and xylose be efficiently consumed using the multi-organism approach? (2) Can this approach be used to accumulate a model product? (3) Can this approach be applied to the removal of an inhibitor, acetate, selectively from mixtures of xylose and glucose? To answer the question of whether this multi-organism approach can effectively consume synthetic mixed sugar solutions, we first tested substrate-selective uptake using two strains, one unable to consume glucose and one unable to consume xylose. The xylose-selective strain ALS998 has mutations in the three genes involved in glucose uptake, rendering it unable to consume glucose: ptsG codes for the Enzyme IICB{sup Glc} of the phosphotransferase system (PTS) for carbohydrate transport (Postma et al., 1993), manZ codes for the IID{sup Man} domain of the mannose PTS permease (Huber, 1996), glk codes for glucokinase (Curtis and Epstein 1975) We also constructed strain ALS1008 which has a knockout in the xylA gene encoding for xylose isomerase, rendering ALS1008 unable to consume xylose. Two batch experiments and one continuous bioprocess were completed. In the first experiment, each strain was grown separately in a defined medium of 8 g/L xylose and 15 g/L glucose which represented xylose and glucose concentrations that can be generated by actual biomass. In the second experiment, the two strains were grown together in batch in the same defined, mixed-sugar medium. In a third experiment, we grew the strains continuously in a 'chemostat', except that we shifted the concentrations of glucose and xylose periodically to observe how the system would respond. (For example, we shifted the glucose concentration suddenly from 15 g/L to 30 g/L in the feed).

Mark A. Eiteman PHD; Elliot Altman Phd

2009-02-11

133

Dilute acid/metal salt hydrolysis of lignocellulosics  

Energy Technology Data Exchange (ETDEWEB)

A modified dilute acid method of hydrolyzing the cellulose and hemicellulose in lignocellulosic material under conditions to obtain higher overall fermentable sugar yields than is obtainable using dilute acid alone, comprising: impregnating a lignocellulosic feedstock with a mixture of an amount of aqueous solution of a dilute acid catalyst and a metal salt catalyst sufficient to provide higher overall fermentable sugar yields than is obtainable when hydrolyzing with dilute acid alone; loading the impregnated lignocellulosic feedstock into a reactor and heating for a sufficient period of time to hydrolyze substantially all of the hemicellulose and greater than 45% of the cellulose to water soluble sugars; and recovering the water soluble sugars.

Nguyen, Quang A. (Golden, CO); Tucker, Melvin P. (Lakewood, CO)

2002-01-01

134

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

135

Hemicellulases in lignocellulose biotechnology: recent patents.  

Science.gov (United States)

Hemicelluloses comprise a major part of renewable plant biomass and therefore have received considerable attention in lignocellulose biotechnology. Hemicelluloses are a heterogeneous group of structural polysaccharides such as xylan, mannan and arabinan named after their major constituent monomeric sugar. Bioconversion of hemicelluloses proceeds through hydrolysis using hemicellulases. A variety of hemicellulases have been identified from mesophilic and thermophilic microorganisms. First prominent industrial application of a hemicellulase was in the area of pulp biobleaching when xylanases were found to be able to reduce use of toxic chlorine oxide. Later many applications of hemicellulases in various areas such as deinking of paper waste, clarification of fruit juices, upgradation of feed, fodder and fibres, and saccharification were revealed. The present review presents an overview of patents related to hemicellulases including xylanases, mannanases, arabionosidases, acetylxylan esterases (AXE) and other accessory enzymes. PMID:24182321

Soni, Hemant; Kango, Naveen

2013-12-01

136

(Biotechnology for the conversion of lignocellulosics)  

Energy Technology Data Exchange (ETDEWEB)

This report summarizes the results of the traveler's participation in the International Energy Agency (IEA) Network planning meeting for Biotechnology for the Conversion of Lignocellulosics,'' held at the Institut Francais du Petrole (IFP), Rueil-Malmaison, France. It also summarizes the results of discussions held at Aston University, Birmingham, UK, with Dr. Martin Beevers with whom the traveler is attempting to initiate a collaborative research project that will be beneficial to ongoing research programs at Oak Ridge National Laboratory (ORNL). The itinerary for the trip is given in Appendix A; the names of the people contacted are listed in Appendix B. Also, pertinent information about the Institut Francais du Petrole is attached (Appendix C). 1 tab.

Woodward, J.

1990-10-25

137

Biological pretreatment for production of lignocellulosic biofuel.  

Science.gov (United States)

Lignocellulosic biomass was submitted to a biological pretreatment prior to a catalytic hydroliquefaction in order to produce biofuel. The biodegradation process was conducted over 3 months in a reactor under controlled conditions. During the biodegradation process the organic matter was characterised and its evolution was correlated with physico-chemical parameters. In parallel with the analysis of the lipidic fraction, analytical pyrolysis was used to monitor bacterial activity. The alterations of branched to linear fatty acids ratio and of mono- to diacids ratio were compared when determined by thermochemolysis and observed in the directly extractable lipids. The evolution of the phytol to the corresponding isoprenoic ketone ratio was observed to be dependent on the desorption technique since it decreases using headspace while it increases using pyrolysis. "Humic"/"fulvic acids" ratio, infrared spectroscopy and thermodifferential analysis were used to determine the degree of OM complexification. PMID:22617032

Lemée, L; Kpogbemabou, D; Pinard, L; Beauchet, R; Laduranty, J

2012-08-01

138

Lignocellulose degradation and humus modification by the fungus Paecilomyces inflatus  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Composting is the biological conversion of solid organic waste into usable end products such as fertilizers, substrates for mushroom production and biogas. Although composts are highly variable in their bulk composition, composting material is generally based on lignocellulose compounds derived from agricultural, forestry, fruit and vegetable processing, household and municipal wastes. Lignocellulose is very recalcitrant; however it is rich and abundant source of carbon and energy. Therefore ...

Kluczek-turpeinen, Beata

2007-01-01

139

Improving enzymatic conversion of lignocellulose to platform sugars  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Increasing demand and uncertain availability of fossil fuels urge us to find alternative resources available in large quantities especially for the petrol-based transportation sector. Lignocellulosic biomass, available worldwide in plant cell walls, is a promising alternative feedstock. It can be depolymerised to sugar monomers, which provide potential raw material for sugar platform-based production of fuels and chemicals. However, the enzymatic saccharification of lignocellulose to platform...

Va?rnai, Aniko?

2012-01-01

140

The chemistry involved in the steam treatment of lignocellulosic materials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Luiz Pereira Ramos

2003-01-01

 
 
 
 
141

Microbial Activity on the Degradation of Lignocellulosic Polysaccharides  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In present world there is an increase in demand for organic waste disposal to minimize pollution and maximize resource recovery. Several workers from various parts of the world have reported successful conversion of waste materials to useful compost. Lignocellulose comprises three different polymer types: lignin, hemicellulose and cellulose. Bioconversion of lignocellulosic material through microbial enzyme to produce fermentable sugars has been given serious consideration and continuous rese...

2001-01-01

142

Techno-economic analysis of lignocellulosic ethanol: A review  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Lignocellulosic ethanol is expected to be commercialised during the next decade as renewable energy for transport. Competiveness with first generation bioethanol and with gasoline is commonly considered in techno-economic analyses for commercial stage. Several existing reviews conclude about the high spread of current and projected production costs of lignocellulosic ethanol due to the significant differences in assumptions concerning the following factors: composition and cost of feedstock, ...

Gnansounou, Edgard; Dauriat, Arnaud

2010-01-01

143

High-throughput Saccharification Assay for Lignocellulosic Materials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Polysaccharides that make up plant lignocellulosic biomass can be broken down to produce a range of sugars that subsequently can be used in establishing a biorefinery. These raw materials would constitute a new industrial platform, which is both sustainable and carbon neutral, to replace the current dependency on fossil fuel. The recalcitrance to deconstruction observed in lignocellulosic materials is produced by several intrinsic properties of plant cell walls. Crystalline cellul...

Gomez, Leonardo D.; Whitehead, Caragh; Roberts, Philip; Mcqueen-mason, Simon J.

2011-01-01

144

Production of lupinus angustifolius protein hydrolysates with improved functional properties  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Protein hydrolysates were obtained from lupin flour and from the purified globulin a-conglutin, and their functional properties were studied. Hydrolysis with alcalase for 60 minutes yielded degrees of hydrolysis ranging from 4% to 11% for lupin flour, and from 4% to 13% for a-conglutin. Protein solubility, oil absorption, foam capacity and stability, emulsifying activity, and emulsion stability of hydrolysates with 6% degree of hydrolysis were determined and compared with the properties...

Lqari, Hassane; Pedroche, Justo; Giro?n-calle, Julio; Vioque, Javier; Milla?n, Francisco

2005-01-01

145

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

146

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

1985-05-03

147

Spent fuel integral experiments  

International Nuclear Information System (INIS)

A series of parallel spent fuel integral experiments are underway at Battelle-Columbus. These experiments are operational in the Battelle hot cell facility and are designed to provide information on effects of cladding degradation on the release of radionuclides from spent fuel waste forms and on combined effects interactions between spent fuel waste forms, the waste package, and the surrounding repository environment. To accomplish these objectives, the integral experiments have been designed the emulate characteristics of repository environments for spent fuel materials in deep-mined repositories in tuff, basalt, and granite media

1986-01-01

148

Antioxidant Effect and Water-Holding Capacity of Roselle (Hibiscus sabdariffa L. Seed Protein Hydrolysates  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this study was to investigate the effect of in-vitro pepsin and pancreatin digestion of proteins extracted from Roselle seed on the production of bioactive peptides. Defatted Roselle seed flour was used to extract different protein fractions namely globulin, albumin and glutelin. The proteins were digested using pepsin (1 h followed by pancreatin (1 h in order to produce hydrolysates with good antioxidant activity. The prepared hydrolysates were as effective as antioxidants in model systems, in scavenging of free radicals and acting as reducing agents. This effect was concentration-dependent and was also influenced by the type of protein fraction. The albumin fraction hydrolysates prepared showed the highest antioxidant activity followed by Glutelin and Globulin hydrolysates respectively (Albumin hydrolysates>Glutelin hydrolysates>Globulin hydrolysates. All of the prepared hydrolysates were also found to be effective in enhancing water-holding capacity and cooking yield in a meat model system. Albumin hydrolysates showed the highest improved meat cooking ability followed by Glutelin and Globulin respectively (Albumin hydrolysates>Glutelin hydrolysates>Globulin hydrolysates. The molecular weight distribution analysis of the hydrolysates was determined and most of the peptides were found between 1000 Da and below. The study findings suggest that Roselle seed protein hydrolysates can be applied as functional food ingredients and that their composition determines their functional properties thus their potential application in the food and feed industries.

Fatoumata Tounkara

2013-06-01

149

Laccase Enzymology in Relation to Lignocellulose Processing  

DEFF Research Database (Denmark)

Several studies have indicated that cellulase action on cellulose fibers and their conversion to glucose is inhibited by lignin and lignin-derived phenolic substances, which are released during the pretreatment of lignocellulosic biomass. A prerequisite for optimization of the cellulose-to-glucose conversion is to either get rid of the inhibitory substances or to alter them in a way, so they no longer decrease the action of cellulases. The main focus in the present work was the investigation of the influence of the enzymes that are being expressed from the white-rot fungi when lignin was present in the cultivation broth, on the cellulase catalyzed hydrolysis of pretreated biomass, and to understand the mechanism of their action on phenolic substances. In this thesis, 44 fungi from the genus Alternaria, Fusarium, Memnoniella, Stemphylium, Ulocladium, Ganoderma, Trametes, and Polyporus were evaluated for their ability to grow on lignocellulosic material, such as sugarcane bagasse â?? a competitive substrate forgrain bioethanol. From this investigation, four white-rot fungi (Ganoderma lucidum, Trametes versicolor, Polyporus brumalis, and Polyporus ciliatus), were selected for the growth on lignin (lignin alkaline) and investigated for production of enzymes under such conditions (Paper I). G. lucidum was found to produce high amounts of laccase which corresponded to its exceptional growth on lignocellulosic substrate and lignin. This observation led to a hypothesis that this particular laccase might act in a synergistic way with cellulase preparations and yield in higher cellulose-to-glucose catalyzed hydrolysis. To test this hypothesis the laccase-rich crude extract from G. lucidum was added to the cellulase catalyzed hydrolysis of cellulose from the pretreated sugarcane bagasse (Paper I). A positive outcome of this reaction, a 17% increase in the total glucose yields during cellulase catalyzed hydrolysis of cellulose, led to amplification of laccase gene and its expression in Pichia pastoris (Paper II). This approach was directed into obtaining a monocomponent laccase enzyme and to prove that the higher yields of cellulose-to-glucose conversion are partly due to the presence of laccase, and are not caused by the other proteins, present in the laccase-rich crude protein extract. The addition of the laccase from G. lucidum, expressed in P. pastoris resulted in a total increase in the glucose yields by 20 and 33% depending on the cellulase cocktail preparation. This discovery is significant considering the fact that the cellulase cocktail preparations, namely Cellic®CTec1 and Cellic®CTec2, are improved in respect to phenolic-derived, and end-substrate inhibitors. Additionally, the molecular dynamics simulations (MD) of the obtained amino acid sequence of the laccase from G. lucidum highlighted a potential mechanism of laccase detoxification of the cellulase-pretreated-biomass-derived inhibitors (Paper II). The mechanism of laccase reaction on the phenolic substrates was further evaluated by the literature study of the reactions that take place in the catalytic pocket of this oxidoreductases and the structural alteration that can lead to a more robust, or completely inactive, laccase (Review paper).

Sitarz, Anna Katarzyna

2013-01-01

150

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

151

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

152

Characterization of flavor of whey protein hydrolysates.  

Science.gov (United States)

Twenty-two whey protein hydrolysates (WPH) obtained from 8 major global manufacturers were characterized by instrumental analysis and descriptive sensory analysis. Proximate analysis, size exclusion chromatography, and two different degrees of hydrolysis (DH) analytical methods were also conducted. WPH were evaluated by a trained descriptive sensory panel, and volatile compounds were extracted by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Eleven representative WPH were selected, and 15 aroma active compounds were quantified by GC-MS via the generation of external standard curves. Potato/brothy, malty, and animal flavors and bitter taste were key distinguishing sensory attributes of WPH. Correlations between bitter taste intensity, degree of hydrolysis (using both methods), and concentration of different molecular weight peptides were documented, with high DH samples having high bitter taste intensity and a high concentration of low molecular weight peptides and vice versa. The four aroma-active compounds out of 40 detected by GC-O present at the highest concentration and with consistently high odor activity values in WPH were Strecker derived products, dimethyl sulfide (DMS), 3-methyl butanal, 2-methyl butanal, and methional. Orthonasal thresholds of WPH were lower (p < 0.05) than basic taste thresholds suggesting that aromatics and bitter taste are both crucial to control in WPH food applications. PMID:20415487

Leksrisompong, Pattarin P; Miracle, R Evan; Drake, Maryanne

2010-05-26

153

40 CFR 180.1246 - Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement of a...  

Science.gov (United States)

...false Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement...1246 Yeast Extract Hydrolysate from Saccharomyces cerevisiae: exemption from the requirement...pesticide Yeast Extract Hydrolysate from Saccharomyces cerevisiae on all food...

2010-07-01

154

Bacterial conversion of lignocellulose to ethanol  

Energy Technology Data Exchange (ETDEWEB)

Technologies for fuel ethanol production from lignocellulose are currently available. The challenge today is to assemble these technologies into a commercial demonstration plant. Bacteria such as Escherichia coli strain KO11 have been specifically engineered to produce ethanol at greater than 90% of theoretical yield (40 g ethanol/L in 48 h) from all sugar constituents in hemicellulose (pentoses and hexoses). Methods have been developed to produce fermentable hemicellulose syrups containing high concentrations of sugars. The effectiveness of strain KO11 has been demonstrated with hemicellulose syrups at the 150-liter scale and with laboratory sugars at the 10,000-liter scale. Additional organisms such as Klebsiella oxytoca strain P2 have been engineered for the simultaneous saccharification and fermentation of cellulose (SSF). Cellulase enzymes is one of the major costs associated with all SSF processes. The new organisms eliminate the need for added cellobiase and in some cases produce part of the endoglucanase. Strain P2 has been tested with bagasse, purified cellulose and mixed waste office paper. A simple method of enzyme recycling was tested using strain P2 with office paper as a substrate. Ethanol yields were prejected to be over 539 liters per metric ton. With onsite production, the estimated cost of cellulose for this process is 8.5 cents (U.S.) per liter.

Ingram, L.O. [Univ. of Florida, Gainesville, FL (United States)

1996-10-01

155

Bioethanol from lignocellulosics: Status and perspectives in Canada.  

Science.gov (United States)

Canada has invested significantly in the development of a domestic bioethanol industry, and it is expected that bioethanol from lignocellulosics will become more desirable to the industry as it expands. Development of the Canadian industry to date is described in this paper, as are examples of domestic research programs focused on both bioconversion and thermochemical conversion to generate biofuels from lignocellulosic biomass. The availability of lignocellulosic residues from agricultural and forestry operations, and the potential biofuel production associated with these residues, is described. The policy tools used to develop the domestic bioethanol industry are explored. A residue-based process could greatly extend the potential of the bioethanol industry in Canada. It is estimated that bioethanol production from residual lignocellulosic feedstocks could provide up to 50% of Canada's 2006 transportation fuel demand, given ideal conversion and full access to these feedstocks. Utilizing lignocellulosic biomass will extend the geographic range of the bioethanol industry, and increase the stability and security of this sector by reducing the impact of localized disruptions in supply. Use of disturbance crops could add 9% to this figure, but not in a sustainable fashion. If pursued aggressively, energy crops ultimately could contribute bioethanol at a volume double that of Canada's gasoline consumption in 2006. This would move Canada towards greater transportation fuel independence and a larger role in the export of bioethanol to the global market. PMID:20006494

Mabee, W E; Saddler, J N

2010-07-01

156

Flash photolysis and pulse radiolysis studies on elastin hydrolysates.  

Science.gov (United States)

The formation of reactive species and free radicals in water soluble elastin hydrolysates have been investigated by pulse radiolysis and flash photolysis. Elastin hydrolysates were obtained by hydrolysis of elastin extracted from aorta. An investigation of the photochemical properties of elastin hydrolysates in water was carried out using nanosecond laser irradiation. The transient spectra of elastin hydrolysates solution excited at 266 nm showed two bands. One of them with maximum at 295 nm and the second one with maximum at 400 nm. The reactions of hydrated electrons and ?OH radicals with elastin have been studied by pulse radiolysis. In the absorption spectra of products resulting from the reaction of elastin with e(aq)(-) small maximum absorption in UV and visible light was observed. In the absorption spectra of products resulting from the reaction of the hydroxyl radicals with elastin two bands were observed. The first one at 320 nm and the second one at 410 nm. Reaction of OH radicals with elastin hydrolysates lead to formation of Tyr phenoxyl radicals with absorption at 410 nm. The influence of the addition of sodium azide NaN3 on the formation of the transients was evaluated. PMID:23702900

Sionkowska, Alina

2013-08-01

157

Desalting Fish Skin Protein Hydrolysates Using Macroporous Adsorption Resin  

Directory of Open Access Journals (Sweden)

Full Text Available Macroporous Adsorption Resin (MAR DA 201-C was used to desalt different Fish Skin Protein Hydrolysates (FSPHs. The FSPHs were obtained by hydrolysis of fish skin using Alcalase in a batch reactor a 60°C and pH 8.25. The ash was removed by adsorbing FSPHs onto MAR. Desorption was achieved by washing with alcohol at different concentrations. Ash content of the FSPHs was reduced from 4.69-5.57 to 1.07-2.48% range. The protein content was enriched from 89.07-90.82 to 94.89-96.38% range. MAR has good hydrolysate recoveries. The use of MAR showed promising results in decolourization and fishy flavour reduction. Nile tilapia and Nile perch skin protein hydrolysates were moderately bitter compared to Grass carp skin protein hydrolysates. The bitter taste in FSPHs was reduced to slightly detectable levels by our sensor panel. The hydrolysates had relatively low molecular weight. The process of applying MAR to desalt and debitter FSPHs is feasible.

Joseph Wasswa

2007-01-01

158

Lupine protein hydrolysates inhibit enzymes involved in the inflammatory pathway.  

Science.gov (United States)

Lupine protein hydrolysates (LPHs) were obtained from a lupine protein isolate (LPI) by enzymatic hydrolysis using two proteases, Izyme AL and Alcalase 2.4 L, and their potential anti-inflammatory capacities were studied by determining their in vitro inhibition of the following enzymes that are involved in the inflammatory process: phospholipase A2 (PLA2), cyclooxygenase 2 (COX-2), thrombin, and transglutaminase (TG). The strongest inhibitory activities toward PLA2 and TG were found in the hydrolysates obtained by hydrolysis with Izyme and subsequently with Alcalase, with more than 70% inhibition obtained in some cases. All of the hydrolysates tested inhibited more than 60% of the COX-2 activity. In no case did the percentage of thrombin activity inhibition exceed 40%. The best inhibitory activities were found in the LPH obtained after 15 min of hydrolysis with Alcalase and in the LPH obtained after 60 min of hydrolysis with Izyme followed by 15 min of hydrolysis with Alcalase. Enzyme kinetic analyses were conducted to determine the Km and Vmax parameters of these two hydrolysates using the Lineweaver-Burk equation. Both hydrolysates competitively inhibited the thrombin and PLA2 activities. In the case of COX-2 and TG, the inhibition appeared to be the mixed type. PMID:24423513

Millán-Linares, María del Carmen; Yust, María del Mar; Alcaide-Hidalgo, Juan María; Millán, Francisco; Pedroche, Justo

2014-05-15

159

Microbial utilization and biopolyester synthesis of bagasse hydrolysates.  

Science.gov (United States)

Cellulosic biomass is a potentially inexpensive renewable feedstock for the biorefineries of fuels, chemicals and materials. Sugarcane bagasse was pretreated in dilute acid solution under moderately severe conditions, releasing sugars and other hydrolysates including volatile organic acids, furfurals and acid soluble lignin. Utilization of the hydrolysates by an aerobic bacterium, Ralstonia eutropha, was investigated to determine if the organic inhibitors can be removed for potential recycling and reuse of the process water. Simultaneous biosynthesis of polyhydroxyalkanoates (PHAs) for the production of value-added bioplastics was also investigated. An inhibitory effect of hydrolysates on microbial activity was observed, but it could be effectively relieved by using (a) a large inoculum, (b) a diluted hydrolysate solution, and (c) a tolerant strain, or a combination of the three. The major organic inhibitors including formic acid, acetic acid, furfural and acid soluble lignin were effectively utilized and removed to low concentration levels (less than 100ppm) while at the same time, PHA biopolyesters were synthesized and accumulated to 57wt% of cell mass under appropriate C/N ratios. Poly(3-hydroxybutyrate) was the predominant biopolyester formed on the hydrolysates, but the cells could also synthesize co-polyesters that exhibit high ductility. PMID:18474421

Yu, Jian; Stahl, Heiko

2008-11-01

160

Spinal cord hydrolysate ameliorate immunological reaction in experimental allergic encephalomyelitis.  

Science.gov (United States)

The aim of this study was to use the hydrolysate of pig spinal cord proteins to induce oral tolerance in the animal model of sclerosis multiplex - experimental allergic encephalomyelitis. The female Lewis rats were fed with hydrolysate of pig spinal cord proteins in two doses for one week before immunization, which was induced by injection of guinea pig spinal cord homogenate. At the peak of clinical symptoms (the 13th day post immunization) the rats were sacrificed and the spleen removed. Splenocytes were suspended in a culture medium and placed in microculture plates. The cells were stimulated with homogenate. The cells were cultured for seven days. Proliferation of splenocytes was estimated by means of methyl-3H thymidine incorporation. In supernatants of cultures of splenocytes the level of cytokines INF-gamma, IL-10, IL-4, and TGF-gamma was measured. It was demonstrated that homogenate-induced splenocytes of hydrolysate-fed rats gave rise to low proliferation as compared to the controls used. The IFN-gamma was inhibited in hydrolysate-fed animals. The hydrolysate of pig spinal cord proteins has a modulatory effect on the immune reaction, particularly on the orally-induced antigen-specific modulation of autoimmune response. PMID:19325643

Kwiatkowska-Patzer, Barbara; Micha?kiewicz, Jacek; Kubiszewska, Izabela; Zieli?ska, Joanna; Kasarello, Kaja; Kurzepa, Katarzyna; Lipkowski, Andrzej W

2009-01-01

 
 
 
 
161

Zinc intestinal absorption: effect of protein hydrolysate  

Energy Technology Data Exchange (ETDEWEB)

Protein breakdown products have a high affinity for Zn and may play a role in the intestinal absorption of this element. Na participates in the transport of certain amino acids and oligopeptides. Therefore, the authors investigated by intestinal perfusion the effectiveness of a protein hydrolysate (PrH) on rat jejunal (J) and ileal (I) absorption of Zn, in the absence or the presence of Na. When isotonic NaCl was present in perfusates containing 0.153 mM Zn, and PrH at a 2:1 molar ratio to the metal, Zn uptake in the J (means +/- SEM, in pmoles Zn/min x cm) declined from 389+/-14 in PrH-free to 254+/-11 with PrH, P<0.001. A comparable decline occurred in the I: 360+/-27 in PrH-free vs. 264+/-17 with PrH, P<0.001. In the absence of Na (isotonicity with glycerol), Zn absorption in the J was unchanged by the addition of PrH in the perfusates (436+/-25 in PrH-free vs. 469+/-21 with PrH, P=NS). In the I there was significant enhancement of Zn absorption (362+/-17 in PrH-free vs. 453+/-16 with PrH, P<0.01). These data indicate that, in both the J and the I, Na-linked uptake of PrH products may compete for transport sites with PrH:Zn complexes and thus reduce overall Zn absorption. In the I, the enhancement of Zn absorption by PrH in the absence of Na is compatible with a Na-independent uptake of PrH:Zn chelates.

Wapnir, R.A.; Stiel, L.

1986-03-05

162

Evaluation of continuous ethanol fermentation of dilute-acid corn stover hydrolysate using thermophilic anaerobic bacterium Thermoanaerobacter BG1L1  

DEFF Research Database (Denmark)

Dilute sulfuric acid pretreated corn stover is potential feedstock of industrial interest for second generation fuel ethanol production. However, the toxicity of corn stover hydrolysate (PCS) has been a challenge for fermentation by recombinant xylose fermenting organisms. In this work, the thermophilic anaerobic bacterial strain Thermoanaerobacter BG1L1 was assessed for its ability to ferment undetoxified PCS hydrolysate in a continuous immobilized reactor system at 70°C. The tested strain showed significant resistance to PCS, and substrate concentrations up to 15% total solids (TS) were fermented yielding ethanol of 0.39â??0.42 g/g-sugars consumed. Xylose was nearly completely utilized (89â??98%) for PCS up to 10% TS, whereas at 15% TS, xylose conversion was lowered to 67%. The reactor was operated continuously for 135 days, and no contamination was seen without the use of any agent for preventing bacterial infections. This study demonstrated that the use of immobilized thermophilic anaerobic bacteria for continuous ethanol fermentation could be promising in a commercial ethanol process in terms of system stability to process hardiness and reactor contamination. The tested microorganism has considerable potential to be a novel candidate for lignocellulose bioconversion into ethanol.

Georgieva, Tania I.; Ahring, Birgitte Kiær

2007-01-01

163

Spent fuel management strategies  

International Nuclear Information System (INIS)

Nuclear fuel cycle is divided into two sections; front end and back end of the fuel cycle. Front end of the fuel cycle, which covers all the activities of the fuel cycle before the fuel goes into the reactor has better developed and well-defined technologies. For storage of the spent fuel which are subjects of the back end of the fuel cycle, the waste management policies are not so well defined. There are three approaches that exist today for management of spent fuel. 1. For once through or open fuel cycles direct disposal of spent fuel in a deep geological repository, 2. For closed fuel cycles reprocessing of spent fuel and recycling of the recovered plutonium and uranium in new mixed oxide (MOX) fuels, 3. The spent fuel is placed in long term interim storage pending a decision as to its ultimate reprocessing or disposal. There are so large scale geological repositories for the final disposal of spent fuel in operation. Studies on suitable site selection, design, construction and licensing take about 30-40 years. Reprocessing, on the other hand, produces plutonium and is therefore under close inspection because of the Non Proliferation Treaty. Today more countries are delaying their final decision about the spent fuel management approach and using the long term interim storage approach

1997-09-03

164

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)

2005-01-01

165

LIGNOCELLULOSIC BIOMASS: A POTENTIAL FEEDSTOCK TO REPLACE PETROLEUM  

Directory of Open Access Journals (Sweden)

Full Text Available Sustainability considerations for product and energy production in a future US economy can be met with lignocellulosic biomass. The age of petroleum as the key resource to meet the US economy requirements is rapidly dwindling, given the limited resources of petroleum, the growing global population, and concurrent detrimental effects on environmental safety. The use of natural and renewable feedstocks such as trees and switchgrass is becoming more attractive; indeed, lignocellulosic biomass is becoming a logical alternative to petroleum in light of looming oil shortages, increases in oil prices, and environmental sustainability considerations. This editorial aims at providing a broad overview of the consider-ations for replacing the US petroleum economy with one based on lignocellulosic biomass.

Lucian A. Lucia

2008-11-01

166

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

167

Elucidating the role of ferrous ion cocatalyst in enhancing dilute acid pretreatment of lignocellulosic biomass  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Recently developed iron cocatalyst enhancement of dilute acid pretreatment of biomass is a promising approach for enhancing sugar release from recalcitrant lignocellulosic biomass. However, very little is known about the underlying mechanisms of this enhancement. In the current study, our aim was to identify several essential factors that contribute to ferrous ion-enhanced efficiency during dilute acid pretreatment of biomass and to initiate the investigation of the mechanisms that result in this enhancement. Results During dilute acid and ferrous ion cocatalyst pretreatments, we observed concomitant increases in solubilized sugars in the hydrolysate and reducing sugars in the (insoluble biomass residues. We also observed enhancements in sugar release during subsequent enzymatic saccharification of iron cocatalyst-pretreated biomass. Fourier transform Raman spectroscopy showed that major peaks representing the C-O-C and C-H bonds in cellulose are significantly attenuated by iron cocatalyst pretreatment. Imaging using Prussian blue staining indicated that Fe2+ ions associate with both cellulose/xylan and lignin in untreated as well as dilute acid/Fe2+ ion-pretreated corn stover samples. Analyses by scanning electron microscopy and transmission electron microscopy revealed structural details of biomass after dilute acid/Fe2+ ion pretreatment, in which delamination and fibrillation of the cell wall were observed. Conclusions By using this multimodal approach, we have revealed that (1 acid-ferrous ion-assisted pretreatment increases solubilization and enzymatic digestion of both cellulose and xylan to monomers and (2 this pretreatment likely targets multiple chemistries in plant cell wall polymer networks, including those represented by the C-O-C and C-H bonds in cellulose.

Wei Hui

2011-11-01

168

Elucidating the Role of Ferrous Ion Cocatalyst in Enhancing Dilute Acid Pretreatment of Lignocellulosic Biomass  

Energy Technology Data Exchange (ETDEWEB)

Recently developed iron cocatalyst enhancement of dilute acid pretreatment of biomass is a promising approach for enhancing sugar release from recalcitrant lignocellulosic biomass. However, very little is known about the underlying mechanisms of this enhancement. In the current study, our aim was to identify several essential factors that contribute to ferrous ion-enhanced efficiency during dilute acid pretreatment of biomass and to initiate the investigation of the mechanisms that result in this enhancement. During dilute acid and ferrous ion cocatalyst pretreatments, we observed concomitant increases in solubilized sugars in the hydrolysate and reducing sugars in the (insoluble) biomass residues. We also observed enhancements in sugar release during subsequent enzymatic saccharification of iron cocatalyst-pretreated biomass. Fourier transform Raman spectroscopy showed that major peaks representing the C-O-C and C-H bonds in cellulose are significantly attenuated by iron cocatalyst pretreatment. Imaging using Prussian blue staining indicated that Fe{sup 2+} ions associate with both cellulose/xylan and lignin in untreated as well as dilute acid/Fe{sup 2+} ion-pretreated corn stover samples. Analyses by scanning electron microscopy and transmission electron microscopy revealed structural details of biomass after dilute acid/Fe{sup 2+} ion pretreatment, in which delamination and fibrillation of the cell wall were observed. By using this multimodal approach, we have revealed that (1) acid-ferrous ion-assisted pretreatment increases solubilization and enzymatic digestion of both cellulose and xylan to monomers and (2) this pretreatment likely targets multiple chemistries in plant cell wall polymer networks, including those represented by the C-O-C and C-H bonds in cellulose.

Wei, H.; Donohoe, B. S.; Vinzant, T. B.; Ciesielski, P. N.; Wang, W.; Gedvilas, L. M.; Zeng, Y.; Johnson, D. K.; Ding, S. Y.; Himmel, M. E.; Tucker, M. P.

2011-01-01

169

Advanced anaerobic bioconversion of lignocellulosic waste for the melissa life support system  

Science.gov (United States)

The feasibility of nearly-complete conversion of lignocellulosic waste (70% food crops, 20% faecal matter and 10% green algae) into biogas was investigated in the context of the MELiSSA loop (Micro-Ecological Life Support System Alternative). The treatment comprised a series of processes, i.e. a mesophilic laboratory scale CSTR (continuously stirred tank reactor), an upflow biofilm reactor, a fiber liquefaction reactor employing the rumen bacterium Fibrobacter succinogenes and a hydrothermolysis system in near-critical water. By the one-stage CSTR, a biogas yield of 75% with a specific biogas production of 0.37 l biogas g-1 VSS (volatile suspended solids) added at a RT (hydraulic retention time) of 20-25 d was obtained. Biogas yields could not be increased considerably at higher RT, indicating the depletion of readily available substrate after 25 d. The solids present in the CSTR-effluent were subsequently treated in two ways. Hydrothermal treatment (T ˜ 310-350C, p ˜ 240 bar) resulted in effective carbon liquefaction (50-60% without and 83% with carbon dioxide saturation) and complete sanitation of the residue. Application of the cellulolytic Fibrobacter succinogenes converted remaining cellulose contained in the CSTR-effluent into acetate and propionate mainly. Subsequent anaerobic digestion of the hydrothermolysis and the Fibrobacter hydrolysates allowed conversion of 48-60% and 30%, respectively. Thus, the total process yielded biogas corresponding with conversions up to 90% of the original organic matter. It appears that particularly mesophilic digestion in conjunction with hydrothermolysis offers interesting features for (nearly) the MELiSSA system. The described additional technologies show that complete and hygienic carbon and energy recovery from human waste within MELiSSA is technically feasible, provided that the extra energy needed for the thermal treatment is guaranteed.

Lissens, G.; Verstraete, W.; Albrecht, T.; Brunner, G.; Creuly, C.; Dussap, G.; Kube, J.; Maerkl, H.; Lasseur, C.

170

Optimisation of the angiotensin converting enzyme inhibition by whey protein hydrolysates using response surface methodology  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Protein hydrolysates inhibiting the angiotensin converting enzyme (ACE) in vitro, are potentially interesting constituents for blood pressure decreasing products. To minimise the amount of hydrolysate needed, the ACE inhibitory activity should be maximised. The total peptide composition of a hydrolysate determines its ACE inhibitory ability and depends on the specificity of the proteolytic enzyme and the process conditions used for the production of the hydrolysate. In the present research, t...

2002-01-01

171

Use of nuclear wastes in utilization of lignocellulosic biomass  

International Nuclear Information System (INIS)

The practices of high energy irradiation of biomass to increase its utility are reviewed. Sugar yield, digestibility to acid and enzymatic hydrolysis, and changes in chemical and physical properties of lignocellulosic materials upon irradiation are investigated. Gamma irradiation at the dose of 50 Mrad or greater extensively degraded and solubilized sugarcane bagasse in water, but direct production of fermentable sugars from biomass by gamma irradiation was difficult because of decomposition of the sugars. Possible use of nuclear wastes (in the form of caesium-137) in utilization of lignocellulosic biomass are discussed. (author)

1982-01-01

172

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

173

Microbial Activity on the Degradation of Lignocellulosic Polysaccharides  

Directory of Open Access Journals (Sweden)

Full Text Available In present world there is an increase in demand for organic waste disposal to minimize pollution and maximize resource recovery. Several workers from various parts of the world have reported successful conversion of waste materials to useful compost. Lignocellulose comprises three different polymer types: lignin, hemicellulose and cellulose. Bioconversion of lignocellulosic material through microbial enzyme to produce fermentable sugars has been given serious consideration and continuous research and development activities has been carried out in laboratories around the world. This article highlights the significant research findings and reviews the state of the art in this very important area of biotechnology.

Zakaria Ahmed

2001-01-01

174

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

175

Production of biomass from enzymatic hydrolysate of agricultural waste  

Energy Technology Data Exchange (ETDEWEB)

An attempt was made to cultivate marine yeasts on hydrolysate produced by saccharification of cellulosic wastes, by the action of cellulases. The cellulases were produced in a 10 l laboratory fermentor with 1% treated rice straw as substrate. A syrup of about 5% glucose could be obtained with a high enzyme concentration in 2.5 days. The hydrolysate proved to be a suitable substrate for the production of microbial biomass, as 5 to 6 g/l of dry yeast cell mass was obtained in 48 hr. The protein content of which ranged from 38 to 48%.

Araujo, A. (Goa College of Pharmacy, India); D' Souza, J.

1980-01-01

176

The spent fuel fate  

International Nuclear Information System (INIS)

The spent fuel is not a waste. It can be upgrade by a reprocessing which extracts all products able to produce energy. The today situation is presented and economically analyzed and future alternatives are discussed. (A.L.B.)

2001-01-01

177

Spent fuel workshop'2002  

International Nuclear Information System (INIS)

This document gathers the transparencies of the presentations given at the 2002 spent fuel workshop: Session 1 - Research Projects: Overview on the IN CAN PROCESSES European project (M. Cowper), Overview on the SPENT FUEL STABILITY European project (C. Poinssot), Overview on the French R and D project on spent fuel long term evolution, PRECCI (C. Poinssot); Session 2 - Spent Fuel Oxidation: Oxidation of uranium dioxide single crystals (F. Garrido), Experimental results on SF oxidation and new modeling approach (L. Desgranges), LWR spent fuel oxidation - effects of burn-up and humidity (B. Hanson), An approach to modeling CANDU fuel oxidation under dry storage conditions (P. Taylor); Session 3 - Spent Fuel Dissolution Experiments: Overview on high burnup spent fuel dissolution studies at FZK/INE (A. Loida), Results on the influence of hydrogen on spent fuel leaching (K. Spahiu), Leaching of spent UO2 fuel under inert and reducing conditions (Y. Albinsson), Fuel corrosion investigation by electrochemical techniques (D. Wegen), A reanalysis of LWR spent fuel flow through dissolution tests (B. Hanson), U-bearing secondary phases formed during fuel corrosion (R. Finch), The near-field chemical conditions and spent fuel leaching (D. Cui), The release of radionuclides from spent fuel in bentonite block (S.S. Kim), Trace actinide behavior in altered spent fuel (E. Buck, B. Hanson); Session 4 - Radiolysis Issues: The effect of radiolysis on UO2 dissolution determined from electrochemical experiments with 238Pu doped UO2 M. Stroess-Gascoyne (F. King, J.S. Betteridge, F. Garisto), doped UO2 studies (V. Rondinella), Preliminary results of static and dynamic dissolution tests with ? doped UO2 in Boom clay conditions (K. Lemmens), Studies of the behavior of UO2 / water interfaces under He2+ beam (C. Corbel), Alpha and gamma radiolysis effects on UO2 alteration in water (C. Jegou), Behavior of Pu-doped pellets in brines (M. Kelm), On the potential catalytic behavior of UO2(s): experimental approach and preliminary results on uranium oxide - water interface (J. Devoy), Preliminary results on studies on radiolysis effects on dissolution of UO2 (E. Ekeroth, M. Jonnson); Session 5 - Modeling of the Spent Fuel Dissolution: tUO2 dissolution and the effect of radiolysis (T. Lundstrom), Prediction of the effect of radiolysis (F. King), Experimental determination and chemical modeling of radiolytic processes at the spent fuel / water interface (E. Cera, J. Bruno, T. Eriksen, M. Grive, L. Duro); Session 6 - Influence of the Potential Evolution prior to the Water Access on IRF: Potential occurrence of ? self-irradiation enhanced-diffusion (H.J. Matzke, T. Petit), Are grain boundaries a stable microstructure? (Y. Guerin), Modeling RN instant release fractions from spent nuclear fuel under repository conditions (C.Poinssot, L. Johnson, P. Lovera). (J.S.)

2002-09-23

178

Degradation of softwood, hardwood, and grass lignocelluloses by two Steptomyces strains  

Energy Technology Data Exchange (ETDEWEB)

Two Streptomyces strains, S. viridosporus T7A and S. setonii 75Vi2, were grown on softwood, hardwood, and grass lignocelluloses, and lignocellulose decomposition was followed by monitoring substrate weight loss, lignin loss, and carbohydrate loss over time. Results showed that both Streptomyces strains substantially degraded both the lignin and the carbohydrate components of each lignocellulose; however, these actinomycetes were more efficient decomposers of grass lignocelluloses than of hardwood or softwood lignocelluloses. In particular, these Streptomyces strains were more efficient decomposers of grass lignins than of hardwood or softwood lignins.

Antai, S.P.; Crawford, D.L.

1981-08-01

179

Degradation of softwood, hardwood, and grass lignocelluloses by two steptomyces strains  

Energy Technology Data Exchange (ETDEWEB)

Two Streptomyces strains, S. viridiosporus T7A and S. setonii 75Vi2, were grown on softwood, hardwood, and grass lignocelluloses, and lignocellulose decomposition was followed by monitoring substrate weight loss, lignin loss, and carbohydrate loss over time. Results showed that both Streptomyces strains substantially degraded both the lignin and the carbohydrate components of each lignocellulose. However, these Streptomyces strains were more efficient decomposers of grass lignocelluloses than of hardwood or softwood lignocelluloses; in particular, they were more efficient decomposers of grass lignins than of hardwood or softwood lignins.

Antal, S.P.; Crawford, D.L.

1981-08-01

180

Screening spent fuels  

International Nuclear Information System (INIS)

A new research facility named 'armored processes chain' (CBP) has been implemented in the Atalante installation of CEA/Valrho (Marcoule, France). This facility will contribute to validate the different steps of the advanced separation process for the separation of the most toxic radionuclides of spent fuels. The chain is tested at a significant scale (15 kg of spent fuel) before its industrial development planned for the beginning of 2005. Short digest paper. (J.S.)

2004-01-01

 
 
 
 
181

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 ["1"4C-lignin]lignocelluloses and ["1"3C-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

1986-01-01

182

Removal and recovery of molybdenum from aqueous solutions by adsorption onto Surfactant-Modified coir pith, a lignocellulosic polymer  

Energy Technology Data Exchange (ETDEWEB)

Coconut coir pith, a lignocellulosic polymer, is an unwanted by-product of the coir fiber industry. The pith was used as a biosorbent for the removal of Molybdenum(VI) after modification with a cationic surfactant, hexadecyltrimethylammonium bromide. The optimum pH for maximum adsorption of Mo(VI) was found to be 3.0. Langmuir, Freundlich and Dubinin Radushkevich isotherms were used to model the adsorption equilibrium data and the system was seen to follow all three isotherms. The Langmuir adsorption capacity of the biosorbent was found to be 57.5 mg g{sup -1}. Kinetic studies showed that the adsorption generally obeyed a second-order kinetic model. Desorption studies showed that the recovery of Mo(VI) from the spent adsorbent was feasible. The effect of foreign anions on the adsorption of Mo(VI) was also examined. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

Namasivayam, Chinnaiya [Environmental Chemistry Division, Department of Environmental Sciences, Bharathiar University, Coimbatore (India); Sureshkumar, Molagoundanpalayam Venkatachalam [Department of Chemistry, PARK College of Engineering and Technology, Coimbatore (India)

2009-01-15

183

Selection of lactic acid bacteria able to ferment inulin hydrolysates  

Directory of Open Access Journals (Sweden)

Full Text Available Eight homofermentative lactic acid bacteria isolates were tested for lactic acid production using chicory and Jerusalem artichoke hydrolysate as substrate. The pH, lactic acid yield and productivity were used to select the best homolactic bacteria for lactic acid production. The selected strains produced lactic acid at maximum yield after 24 hours of fermentation and the productivity was greater at 24 hours of fermentation. From all studied strains, Lb1 and Lb2 showed the best results regarding lactic acid yields andproductivity. After 48 hours of chicory and Jerusalem artichhoke hydrolysates fermentation, from all the studied strains, Lb2 produced the highest lactic acid yield (0.97%. Lb2 produced after 48 hours of fermentation the lowest pH value of 3.45±0.01. Lb2 showed greater lactic acid productivity compared to the other studied lactic acid bacteria, the highest values, 0.13 g·L-1·h-1fromJerusalem artichoke hydrolysate and 0.11g·L-1·h-1 from chicory hydrolysate, being produced after 24 hours of fermentation.

Octavian BASTON

2012-12-01

184

Radiation hydrolysate of tuna cooking juice with enhanced antioxidant properties  

International Nuclear Information System (INIS)

Tuna protein hydrolysates are of increasing interest because of their potential application as a source of bioactive peptides. Large amounts of tuna cooking juice with proteins and extracts are produced during the process of tuna canning, and these cooking juice wastes cause environmental problems. Therefore, in this study, cooking juice proteins were hydrolyzed by irradiation for their utilization as functional additives. The degree of hydrolysis of tuna cooking juice protein increased from 0% to 15.1% at the absorbed doses of 50 kGy. To investigate the antioxidant activity of the hydrolysate, it was performed the ferric reducing antioxidant power (FRAP) assay, and the lipid peroxidation inhibitory and superoxide radical scavenging activities were measured. The FRAP values increased from 1470 ?M to 1930 ?M and IC50 on superoxide anion was decreased from 3.91 ?g/mL to 1.29 ?g/mL at 50 kGy. All of the antioxidant activities were increased in the hydrolysate, suggesting that radiation hydrolysis, which is a simple process that does not require an additive catalysts or an inactivation step, is a promising method for food and environmental industries. - Highlights: ? Radiation was applied for the hydrolysis of tuna cooking juice protein. ? The degree of hydrolysis were increased by irradiation and the antioxidant activity of hydrolysate was higher than protein. ? This result suggest that radiation is useful method for the hydrolysis of protein.

2012-08-01

185

Development of Silane Hydrolysate Binder for Thermal-Control Coatings  

Science.gov (United States)

Technical report describes theoretical and experimental development of methyltriethoxysilane (MTES) hydrolysate binder for white, titanium dioxidepigmented thermal-control coatings often needed on satellites. New coating is tougher and more abrasion-resistant than conventional coating, S-13G, which comprises zinc oxide in hydroxyl-therminated dimethylsiloxane binder.

Patterson, W. J.

1983-01-01

186

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

1994-01-01

187

[Anaerobic digestion of lignocellulosic biomass with animal digestion mechanisms].  

Science.gov (United States)

Lignocellulosic material is the most abundant renewable resource in the earth. Herbivores and wood-eating insects are highly effective in the digestion of plant cellulose, while anaerobic digestion process simulating animal alimentary tract still remains inefficient. The digestion mechanisms of herbivores and wood-eating insects and the development of anaerobic digestion processes of lignocellulose were reviewed for better understanding of animal digestion mechanisms and their application in design and operation of the anaerobic digestion reactor. Highly effective digestion of lignocellulosic materials in animal digestive system results from the synergistic effect of various digestive enzymes and a series of physical and biochemical reactions. Microbial fermentation system is strongly supported by powerful pretreatment, such as rumination of ruminants, cellulase catalysis and alkali treatment in digestive tract of wood-eating insects. Oxygen concentration gradient along the digestive tract may stimulate the hydrolytic activity of some microorganisms. In addition, the excellent arrangement of solid retention time, digesta flow and end product discharge enhance the animal digestion of wood cellulose. Although anaerobic digestion processes inoculated with rumen microorganisms based rumen digestion mechanisms were developed to treat lignocellulose, the fermentation was more greatly limited by the environmental conditions in the anaerobic digestion reactors than that in rumen or hindgut. Therefore, the anaerobic digestion processes simulating animal digestion mechanisms can effectively enhance the degradation of wood cellulose and other organic solid wastes. PMID:23668159

Wu, Hao; Zhang, Pan-Yue; Guo, Jian-Bin; Wu, Yong-Jie

2013-02-01

188

Lignocellulose pretreatment: a comparison of wet and dry ball attrition  

Energy Technology Data Exchange (ETDEWEB)

A comparison of wet and dry ball attrition of various lignocellulosic substrates indicates that terminal crystallinity index following enzymatic hydrolysis usually decreases after wet attrition and increases after dry attrition. Particle size was reduced to a greater extent in dry attrition in accordance with increased friability. Conversions favored neither wet nor dry pretreatment, indicating substrate specific requirements. (Refs. 14).

Rivers, D.B.; Emert, G.H.

1987-01-01

189

Thermoanalytical study of the carbonization process in lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

Thermogravimetry and differential thermal analysis were applied to observe the carbonization process in oak wood and lignocellulose derived from it as influenced by temperature increase, sample size and concentration of oxygen in gas phase. Quantitative and qualitative analysis showed that these parameters have a substantive effect on the process.

Balcerowiak, W.; Maciejewski, Z.

1982-01-01

190

Swedish developments in biotechnology based on lignocellulosic materials  

Energy Technology Data Exchange (ETDEWEB)

The basic research on enzyme mechanisms involved in the fungal degradation of cellulose and lignin for conversion of biomass to chemicals and fuel-grade EtOH are discussed. The biotechnical processes based on lignocellulosic materials and Swedish biomass resources are described. (Refs. 34).

Eriksson, K.E.

1981-01-01

191

Cellulase production using biomass feed stock and its application in lignocellulose saccharification for bio-ethanol production  

Energy Technology Data Exchange (ETDEWEB)

A major constraint in the enzymatic saccharification of biomass for ethanol production is the cost of cellulase enzymes. Production cost of cellulases may be brought down by multifaceted approaches which include the use of cheap lignocellulosic substrates for fermentation production of the enzyme, and the use of cost efficient fermentation strategies like solid state fermentation (SSF). In the present study, cellulolytic enzymes for biomass hydrolysis were produced using solid state fermentation on wheat bran as substrate. Crude cellulase and a relatively glucose tolerant BGL were produced using fungi Trichoderma reesei RUT C30 and Aspergillus niger MTCC 7956, respectively. Saccharification of three different feed stock, i.e. sugar cane bagasse, rice straw and water hyacinth biomass was studied using the enzymes. Saccharification was performed with 50 FPU of cellulase and 10 U of {beta}-glucosidase per gram of pretreated biomass. Highest yield of reducing sugars (26.3 g/L) was obtained from rice straw followed by sugar cane bagasse (17.79 g/L). The enzymatic hydrolysate of rice straw was used as substrate for ethanol production by Saccharomyces cerevisiae. The yield of ethanol was 0.093 g per gram of pretreated rice straw. (author)

Sukumaran, Rajeev K.; Singhania, Reeta Rani; Mathew, Gincy Marina; Pandey, Ashok [Biotechnology Division, National Institute for Interdisciplinary Science and Technology, CSIR, Trivandrum-695 019 (India)

2009-02-15

192

Effect of Protein Hydrolysates on Pancreatic Cancer Cells  

DEFF Research Database (Denmark)

Effect of Fish Protein Hydrolysates on Pancreatic Cancer Cells Carlo G. Ossum1, Lisa Lystbæk Andersen2, Henrik Hauch Nielsen2, Else K. Hoffmann1, and Flemming Jessen2 1University of Copenhagen, Department of Biology, Denmark, 2Technical University of Denmark (DTU), National Food Institute, Denmark Corresponding author: Carlo G. Ossum (cgossum@gmail.com) A large number of bioactive peptides have been identified in and isolated from various food sources. Milk seems to be a particularly rich source but also different fish species have been found to yield bioactive peptides. Bioactive peptides, usually consisting of 3 to 20 amino acids, can be released from proteins upon degradation by proteolytic enzymes, e.g. in the intestinal tract. The numerous described bioactivities include antihypertensive, anticancerous, antimicrobial, and immunomodulating effects. Here, we investigate the effect of fish protein hydrolysates obtained by enzymatic hydrolysis on cancer cell proliferation. Skin and belly flap muscle from trout were hydrolysed with the unspecific proteases Alcalase, Neutrase, or UE1 (all from Novozymes, Bagsværd, Denmark) to a hydrolysis degree of 1-15%. The hydrolysates were tested for biological activities affecting cell proliferation and ability to modulate caspase activity in pancreatic cancer cells COLO357 and BxPC-3 in vitro. A number of the hydrolysates showed caspase promoting activity; in particular products containing muscle tissue, i.e. belly flap, were able to stimulate caspase activity. Selected hydrolysis products were further fractionated by ultrafiltration into molecular sizes above and below 5 kDa and their activity and dose-dependence was tested.

Ossum, Carlo G.; Andersen, Lisa Lystbæk

193

Production of Lupinus angustifolius protein hydrolysates with improved functional properties  

Directory of Open Access Journals (Sweden)

Full Text Available Protein hydrolysates wer e obtained from lupin flour and from the purified globulin α -conglutin, and their functional properties were studied. Hydrolysis with alcalase for 60 minutes yielded degrees of hydrolysis ranging from 4 % to 11 % for lupin flour, and from 4 % to 13% for α -conglutin. Protein solubility, oil absorption, foam capacity and stability, emulsifying activity, and emulsion stability of hydrolysates with 6% degree of hydrolysis were determined and compared with the properties of the original flour. The protein hydrolysates showed better functional properties than the original proteins. Most importantly, the solubility of the α -conglutin and L. angustifolius flour hydrolysates was increased by 43 % and 52 %, respectively. Thus, lupin seed protein hydrolysates have improved functional properties and could be used in the elaboration of a variety of products such as breads, cakes, and salad dressings.Se obtuvieron hidrolizados proteicos de la harina del altramuz y de la globulina α - conglutina purificada y se estudiaron sus propiedades funcionales. La hidrólisis con alcalasa durante 60 minutos produjo hidrolizados con grados de hidrólisis entre el 4 % y el 11 % para la harina y entre el 4 % y el 13 % para la α - conglutina. Se estudió en un hidrolizado con un 6 % de grado de hidrólisis la solubilidad proteica, absorción de aceite, capacidad y estabilidad espumante y actividad y estabilidad emulsificante. Los hidrolizados proteicos mostraron mejores propiedades funcionales que las proteínas originales. Más aún, la solubilidad de los hidrolizados de α - conglutina y la harina se incrementó en un 43 % y 52 % respectivamente. Así pues, hidrolizados de proteínas de semilla de lupino presentan mejores propiedades funcionales y podrían usarse en la elaboración de productos como pan, dulces, salsas o cremas.

Millán, Francisco

2005-06-01

194

Enzymatic hydrolysis of spent coffee ground.  

Science.gov (United States)

Spent coffee ground (SCG) is the main residue generated during the production of instant coffee by thermal water extraction from roasted coffee beans. This waste is composed mainly of polysaccharides such as cellulose and galactomannans that are not solubilised during the extraction process, thus remaining as unextractable, insoluble solids. In this context, the application of an enzyme cocktail (mannanase, endoglucanase, exoglucanase, xylanase and pectinase) with more than one component that acts synergistically with each other is regarded as a promising strategy to solubilise/hydrolyse remaining solids, either to increase the soluble solids yield of instant coffee or for use as raw material in the production of bioethanol and food additives (mannitol). Wild fungi were isolated from both SCG and coffee beans and screened for enzyme production. The enzymes produced from the selected wild fungi and recombinant fungi were then evaluated for enzymatic hydrolysis of SCG, in comparison to commercial enzyme preparations. Out of the enzymes evaluated on SCG, the application of mannanase enzymes gave better yields than when only cellulase or xylanase was utilised for hydrolysis. The recombinant mannanase (Man1) provided the highest increments in soluble solids yield (17 %), even when compared with commercial preparations at the same protein concentration (0.5 mg/g SCG). The combination of Man1 with other enzyme activities revealed an additive effect on the hydrolysis yield, but not synergistic interaction, suggesting that the highest soluble solid yields was mainly due to the hydrolysis action of mannanase. PMID:23436225

Jooste, T; García-Aparicio, M P; Brienzo, M; van Zyl, W H; Görgens, J F

2013-04-01

195

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

196

Spent fuel management  

International Nuclear Information System (INIS)

The light-water reactor (LWR) fuel cycle has always been based on the assumption that the spent fuel would stay for between one and three years in storage basins at the reactor before being reprocessed. Only a limited storage capacity is required in the fast breeder reactor (FBR) fuel cycle, since early reprocessing - to recover the new fissile material ''bred'' in the reactor - is an integral component of the fuel cycle. On the other hand, it was originally intended that spent fuel from Candu heavy-water reactors (HWR) should be stored permanently and not reprocessed. Delays in implementing the LWR reprocessing step have occurred in some States as questions have arisen about technologies, economics of the nuclear industry, the choice of fuel cycle, and the political aspects of non-proliferation. As a result of the increased need for extended storage of LWR spent fuel and of a review of the eventual recycle of HWR spent fuel, methods for the interim storage of spent fuel and for its eventual recycling are being considered afresh

1981-01-01

197

Spent fuel reprocessing options  

International Nuclear Information System (INIS)

The objective of this publication is to provide an update on the latest developments in nuclear reprocessing technologies in the light of new developments on the global nuclear scene. The background information on spent fuel reprocessing is provided in Section One. Substantial global growth of nuclear electricity generation is expected to occur during this century, in response to environmental issues and to assure the sustainability of the electrical energy supply in both industrial and less-developed countries. This growth carries with it an increasing responsibility to ensure that nuclear fuel cycle technologies are used only for peaceful purposes. In Section Two, an overview of the options for spent fuel reprocessing and their level of development are provided. A number of options exist for the treatment of spent fuel. Some, including those that avoid separation of a pure plutonium stream, are at an advanced level of technological maturity. These could be deployed in the next generation of industrial-scale reprocessing plants, while others (such as dry methods) are at a pilot scale, laboratory scale or conceptual stage of development. In Section Three, research and development in support of advanced reprocessing options is described. Next-generation spent fuel reprocessing plants are likely to be based on aqueous extraction processes that can be designed to a country specific set of spent fuel partitioning criteria for recycling of fissile materials to advanced light water reactors or fast spectrum reactors. The physical design of these plants must incorporate effective means for materials accountancy, safeguards and physical protection. Section four deals with issues and challenges related to spent fuel reprocessing. The spent fuel reprocessing options assessment of economics, proliferation resistance, and environmental impact are discussed. The importance of public acceptance for a reprocessing strategy is discussed. A review of modelling tools to support the development of advanced nuclear fuel cycles is also given. As a conclusion, spent fuel reprocessing options have evolved significantly since the start of nuclear energy application. There is a large body of industrial experience in fuel cycle technologies complemented by research and development programs in several countries

2008-01-01

198

Transportation of spent fuels  

International Nuclear Information System (INIS)

JMTR (Japan Material Test Reactor) of JAERI, Oarai Establishment, transported spent fuels from JMTR reactor to Savannah River Site, US DOE, in June 1997, for the first time since the US Government adopted a new policy for accepting spent fuels from foreign research reactors (New Off-Site Fuel Policy, 1993). The present report describes the details of the transportation. It includes the characteristics of the fuel elements, the fuel casks used, the storage facilities, the necessary administrative procedures, an outline of the contract, and examinations to confirm the safety during transportation by sea and by land made from Japan side and also US DOE side (S. Ohno)

1998-03-01

199

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

200

Spent fuel counter  

Energy Technology Data Exchange (ETDEWEB)

In many cases the IAEA must inspect spent fuel shipping casks before they leave facilities. Similarly, inspections may be required at the location where a cask is received and unloaded. In order to reduce the number of inspections required, it would be desirable to develop a system to count spent fuel assemblies as they are loaded or removed from shipping casks. This report discusses several methods which potentially could be used for performing this function. A concept for a Spent Fuel Counter System is proposed which uses a Laser Surveillance System (LASSY), Cerenkov Viewing Device (CVD), and Modular Integrated Video System (MIVS), all coupled together. In the proposed system, LASSY would provide an indication that an object is being placed into or removed from the cask, the CVD would be used to determine if the object has the radiation characteristics of a spent fuel assembly, and the MIVS would record the information. The system may need to be designed so that the operator could determine that it was operating correctly during the loading operations. This would help prevent anomalies from occurring which could only be resolved through reverification measures. Before such a system could be implemented testing would be necessary to determine that the individual components would each work adequately in this application. The issues of reliability, intrusiveness, and cask sealing should also be addressed before a development program is undertaken. 12 refs., 1 fig.

Drayer, D.D.

1988-09-01

 
 
 
 
201

Flow-through biological conversion of lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

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

202

Feasibility study of energy use for densificated lignocellulosic material (briquettes)  

Energy Technology Data Exchange (ETDEWEB)

A study is made of a series of briquettes made from forest or industrial waste, some types of which have not to date been used in briquettes. They are evaluated from both an energy and economic viewpoint. Lignocellulosic densification improves the birquettes' behavior as a fuel by increasing the homogeneity and by being easier to transport and manage. Lignocellulosic binderless briquettes' characteristic net heating value (LHV) and remaining amount of fuel during combustion (Weight) have been investigated to obtain a general expression function of production and raw material factors. In both cases the main factor is the fixed carbon in a quadratic way as all the factors are easily measurable. 36 refs., 6 figs., 6 tabs.

Tabares, J.L.M.; Ortiz, L.; Granada, E.; Viar, F.P. [Technical School of Industrial Engineering, Vigo (Spain)

2000-08-01

203

Characterization of the ATP-hydrolysing activity of ?-sarcoglycan  

Science.gov (United States)

?-Sarcoglycan is a glycoprotein associated with the dystrophin complex at sarcolemma of skeletal and cardiac muscles. Gene defects in ?-sarcoglycan lead to a severe muscular dystrophy whose molecular mechanisms are not yet clear. A first insight into the function of ?-sarcoglycan was obtained by finding that it is an ATP-binding protein and that it probably confers ability to hydrolyse ATP to the purified dystrophin complex [Betto, Senter, Ceoldo, Tarricone, Biral and Salviati (1999) J. Biol. Chem. 274, 7907–7912]. In the present study, we present definitive evidence showing that ?-sarcoglycan is an ATP-hydrolysing enzyme. The appearance of ?-sarcoglycan protein expression was correlated with the increase in ecto-nucleotidase activity during differentiation of C2C12 cells. Approx. 25% of ecto-nucleotidase activity displayed by the C2C12 myotubes was inhibited by preincubating cells with an antibody specific for the ATP-binding motif of ?-sarcoglycan. This demonstrates that ?-sarcoglycan substantially contributes to total ecto-nucleotidase activity of C2C12 myotubes. To characterize further this activity, human embryonic kidney 293 cells were transfected with expression plasmids containing ?-sarcoglycan cDNA. Transfected cells exhibited a significant increase in the ATP-hydrolysing activity that was abolished by the anti-?-sarcoglycan antibody. The enzyme had a substrate specificity for ATP and ADP, did not hydrolyse other triphosphonucleosides, and the affinity for ATP was in the low mM range. The ATPase activity strictly required the presence of both Mg2+ and Ca2+ and was completely inhibited by suramin and reactive blue-2. These results show that ?-sarcoglycan is a Ca2+, Mg2+-ecto-ATPDase. The possible consequences of the absence of ?-sarcoglycan activity in the pathogenesis of muscular dystrophy are discussed.

2004-01-01

204

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

205

Production and use of lignocellulosic bioethanol in Europe: Current situation and perspectives  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Contrary to the case of the United States where a systematic management of the RD&D on lignocellulosic ethanol prevails, in Europe the research works remain fragmented despite the efforts made by the European Union and in few member states. In most of the European countries, sustainable lignocellulosic resources may not be widely available in the future for bioethanol production due to the possible competition between several potential usages. Thus the actual deployment of the lignocellulosic...

Gnansounou, Edgard

2010-01-01

206

Production by Streptomyces viridosporus T7A of an Enzyme Which Cleaves Aromatic Acids from Lignocellulose †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The lignocellulose-degrading actinomycete Streptomyces viridosporus T7A produced an extracellular esterase when grown in a mineral salts-yeast extract medium. Extracellular esterase activity was first detected during the late stationary phase and typically followed the appearance of intracellular activity. When the organism was grown in lignocellulose-supplemented medium, esterase activity was not increased, but lignocellulose-esterified p-coumaric acid and vanillic acid were released into th...

1988-01-01

207

Exploiting the inter-strain divergence of Fusarium oxysporum for microbial bioprocessing of lignocellulose to bioethanol  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Microbial bioprocessing of lignocellulose to bioethanol still poses challenges in terms of substrate catabolism. A targeted evolution-based study was undertaken to determine if inter-strain microbial variability could be exploited for bioprocessing of lignocellulose to bioethanol. The microorganism studied was Fusarium oxysporum because of its capacity to both saccharify and ferment lignocellulose. Strains of F. oxysporum were isolated and assessed for their genetic variability. Using optimis...

2012-01-01

208

Chemical and Physicochemical Pretreatment of Lignocellulosic Biomass: A Review  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Overcoming the recalcitrance (resistance of plant cell walls to deconstruction) of lignocellulosic biomass is a key step in the production of fuels and chemicals. The recalcitrance is due to the highly crystalline structure of cellulose which is embedded in a matrix of polymers-lignin and hemicellulose. The main goal of pretreatment is to overcome this recalcitrance, to separate the cellulose from the matrix polymers, and to make it more accessible for enzymatic hydrolysis. Reports have sh...

Brodeur, Gary; Yau, Elizabeth; Badal, Kimberly; Collier, John; Ramachandran, K. B.; Ramakrishnan, Subramanian

2011-01-01

209

STEAM EXPLOSION : PROCESS AND IMPACT ON LIGNOCELLULOSIC MATERIAL  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Steam explosion is a thermomechanochemical process which allows the breakdown of lignocellulosic structural components by steam heating, hydrolysis of glycosidic bonds by organic acid formed during the process and shearing forces due to the expansion of the moisture. The process is composed of two distinct stages: vapocracking and explosive decompression. Cumul effects of both phases include modification of the physical properties of the material (specific surface area, water retention capaci...

Jacquet, Nicolas; Vanderghem, Caroline; Danthine, Sabine; Blecker, Christophe; Paquot, Michel

2012-01-01

210

Utilization of Lignocellulosic Waste for the Preparation of Nitrogenous Biofertilizer  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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. chrooco...

Malik, Farhat R.; Soaliha Ahmed; Rizki, Yazdana M.

2001-01-01

211

Lignocellulosic Ethanol Production Potential and Regional Transportation Fuel Demand  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Road traffic dominates in domestic Swedish transportation and is highly dependent on fossil fuels, petrol and diesel. Currently, the use of renewable fuels in transportation accounts for less than 6% of the total energy use in transport. The demand for bioethanol to fuel transportation is growing and cannot be met through current domestic production alone. Lignocellulosic ethanol derived from agricultural crop residues may be a feasible alternative source of ethanol for securing a consistent ...

2011-01-01

212

Role of lignin in the enzymatic hydrolysis of lignocellulose  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

213

SO2 -ethanol-water (SEW) fractionation of lignocellulose  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This study deals with SO2-ethanol-water (SEW) fractionation as a potential method for a Lignocellulosic Biorefinery to achieve high yield separation of the three important components of biomass; cellulose, hemicelluloses and lignin. Representatives of all principal biomass species were successfully treated by SEW fractionation at similar rates. The kinetics of delignification, polysaccharides removal and cellulose hydrolysis at different temperatures and SO2 concentrations are described and i...

2011-01-01

214

Bioflavour production from orange peel hydrolysate using immobilized Saccharomyces cerevisiae.  

Science.gov (United States)

The rising trend of bioflavour synthesis by microorganisms is hindered by the high manufacturing costs, partially attributed to the cost of the starting material. To overcome this limitation, in the present study, dilute-acid hydrolysate of orange peel was employed as a low-cost, rich in fermentable sugars substrate for the production of flavour-active compounds by Saccharomyces cerevisiae. With this purpose, the use of immobilized cell technology to protect cells against the various inhibitory compounds present in the hydrolysate was evaluated with regard to yeast viability, carbon and nitrogen consumption and cell ability to produce flavour active compounds. For cell immobilization the encapsulation in Ca alginate beads was used. The results were compared with those obtained using free-cell system. Based on the data obtained immobilized cells showed better growth performance and increased ability for de novo synthesis of volatile esters of "fruity" aroma (phenylethyl acetate, ethyl hexanoate, octanoate, decanoate and dodecanoate) than those of free cells. The potential for in situ production of new formulations containing flavour-active compounds derive from yeast cells and also from essential oil of orange peel (limonene, ?-terpineol) was demonstrated by the fact that bioflavour mixture was found to accumulate within the beads. Furthermore, the ability of the immobilized yeast to perform efficiently repeated batch fermentations of orange peel hydrolysate for bioflavour production was successfully maintained after six consecutive cycles of a total period of 240 h. PMID:23995224

Lalou, Sofia; Mantzouridou, Fani; Paraskevopoulou, Adamantini; Bugarski, Branko; Levic, Steva; Nedovic, Victor

2013-11-01

215

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

216

Recent advances in production of succinic acid from lignocellulosic biomass.  

Science.gov (United States)

Production of succinic acid via separate enzymatic hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) are alternatives and are environmentally friendly processes. These processes have attained considerable positions in the industry with their own share of challenges and problems. The high-value succinic acid is extensively used in chemical, food, pharmaceutical, leather and textile industries and can be efficiently produced via several methods. Previously, succinic acid production via chemical synthesis from petrochemical or refined sugar has been the focus of interest of most reviewers. However, these expensive substrates have been recently replaced by alternative sustainable raw materials such as lignocellulosic biomass, which is cheap and abundantly available. Thus, this review focuses on succinic acid production utilizing lignocellulosic material as a potential substrate for SSF and SHF. SSF is an economical single-step process which can be a substitute for SHF - a two-step process where biomass is hydrolyzed in the first step and fermented in the second step. SSF of lignocellulosic biomass under optimum temperature and pH conditions results in the controlled release of sugar and simultaneous conversion into succinic acid by specific microorganisms, reducing reaction time and costs and increasing productivity. In addition, main process parameters which influence SHF and SSF processes such as batch and fed-batch fermentation conditions using different microbial strains are discussed in detail. PMID:24292125

Akhtar, Junaid; Idris, Ani; Abd Aziz, Ramlan

2014-02-01

217

Purification and identification of antioxidant peptides from walnut (Juglans regia L.) protein hydrolysates.  

Science.gov (United States)

Walnut proteins were hydrolyzed separately using three different proteases to obtain antioxidant peptides. The antioxidant activities of the hydrolysates were measured using 1,1-diphenyl-2-picryl hydrazyl (DPPH) assay. Among hydrolysates, pepsin hydrolysate obtained by 3h exhibited the highest antioxidant activities, which could also quench the hydroxyl radical, chelate ferrous ion, exhibit reducing power and inhibit the lipid peroxidation. Then, 3-h pepsin hydrolysates were purified sequentially by ultrafiltration, gel filtration and RP-HPLC. The sequence of the peptide with the highest antioxidative activity was identified to be Ala-Asp-Ala-Phe (423.23 Da) using RP-HPLC-ESI-MS, which was identified for the first time from walnut protein hydrolysates. Last, the inhibition of the peptide on lipid peroxidation was similar with that of reduced glutathione (GSH). These results indicate that the protein hydrolysates and/or its isolated peptides may be effectively used as food additives. PMID:23022588

Chen, Ning; Yang, Hongmei; Sun, Yi; Niu, Jun; Liu, Shuying

2012-12-01

218

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

219

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)

1979-01-01

220

Hemicellulases and auxiliary enzymes for improved conversion of lignocellulosic biomass to monosaccharides  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background High enzyme loading is a major economic bottleneck for the commercial processing of pretreated lignocellulosic biomass to produce fermentable sugars. Optimizing the enzyme cocktail for specific types of pretreated biomass allows for a significant reduction in enzyme loading without sacrificing hydrolysis yield. This is especially important for alkaline pretreatments such as Ammonia fiber expansion (AFEX pretreated corn stover. Hence, a diverse set of hemicellulases supplemented along with cellulases is necessary for high recovery of monosaccharides. Results The core fungal cellulases in the optimal cocktail include cellobiohydrolase I [CBH I; glycoside hydrolase (GH family 7A], cellobiohydrolase II (CBH II; GH family 6A, endoglucanase I (EG I; GH family 7B and ?-glucosidase (?G; GH family 3. Hemicellulases tested along with the core cellulases include xylanases (LX1, GH family 10; LX2, GH family 10; LX3, GH family 10; LX4, GH family 11; LX5, GH family 10; LX6, GH family 10, ?-xylosidase (L?X; GH family 52, ?-arabinofuranosidase (LArb, GH family 51 and ?-glucuronidase (L?Gl, GH family 67 that were cloned, expressed and/or purified from different bacterial sources. Different combinations of these enzymes were tested using a high-throughput microplate based 24 h hydrolysis assay. Both family 10 (LX3 and family 11 (LX4 xylanases were found to most efficiently hydrolyze AFEX pretreated corn stover in a synergistic manner. The optimal mass ratio of xylanases (LX3 and LX4 to cellulases (CBH I, CBH II and EG I is 25:75. L?X (0.6 mg/g glucan is crucial to obtaining monomeric xylose (54% xylose yield, while LArb (0.6 mg/g glucan and L?Gl (0.8 mg/g glucan can both further increase xylose yield by an additional 20%. Compared with Accellerase 1000, a purified cocktail of cellulases supplemented with accessory hemicellulases will not only increase both glucose and xylose yields but will also decrease the total enzyme loading needed for equivalent yields. Conclusions A diverse set of accessory hemicellulases was found necessary to enhance the synergistic action of cellulases hydrolysing AFEX pretreated corn stover. High glucose (around 80% and xylose (around 70% yields were achieved with a moderate enzyme loading (~20 mg protein/g glucan using an in-house developed cocktail compared to commercial enzymes.

Hermanson Spencer

2011-02-01

 
 
 
 
221

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.)

1993-01-01

222

3-year midterm results following hydrolyser{sup TM} thrombolysis; Langzeit-Ergebnisse nach Hydrolyser-unterstuetzter Angioplastie - eine prospektive Studie  

Energy Technology Data Exchange (ETDEWEB)

Purpose: Data of a three-year follow-up after mechanical thrombolysis with the Hydrolyser catheter were evaluated. Patients have otherwise been treated by local thrombolysis. Method: 35 patients were treated by thrombolysis, balloon angioplasty, aspiration, local thrombolysis, and stent placement, if necessary. Morphological results following Hydrolyser treatment and additional treatment were evaluated. Results: Following Hydrolyser treatment a significant reduction of the degree and length of the occlusion was observed. Primary clinical success was 80%. Patency rate after 3 years was 0.5. 23% of all patients died in the follow-up period. Conclusion: The Hydrolyser treatment is a relevant alternative to local thrombolysis. This method reduces the time of treatment. The authors favor the lateral opening of the catheter to remove mural thrombus. (orig.) [German] Ziel: Auswertung der Nachkontrollen von Patienten, die anstelle einer lokalen Lyse mit dem Hydrolyser {sup trademark} -Thrombektomiekatheter (HT), Ballondilatation (PTA), Aspirationsthrombektomie (PAT) oder Stent behandelt wurden. Methode: 35 Patienten wurden behandelt und ueber drei Jahre nachbeobachtet. Alle Patienten hatten thromotische/thrombembolische Verschluesse der unteren Extremitaet. Die Laesionen wurden alle mit dem Hydrolyser {sup trademark} -Katheter behandelt. Abhaengig von der Art der Laesion wurden die unterschiedlichen Zusatzverfahren eingesetzt. Das morphologische Resultat wurde sowohl nach dem Einsatz des Hydrolysers {sup trademark} als auch nach der sekundaeren Therapie beurteilt. Ergebnis: Nach Verwendung des Hydrolysers konnte in 21 Faellen eine weitgehende Rekanalisation erreicht werden. Nach sekundaerer Angioplastie wurde in 31 Faellen ein zufrieden-stellendes Resultat (keine relevante Reststenose) erzielt. Die primaere klinische Erfolgsrate lag bei 28/35 (80%). Die Offenheitsrate nach drei Jahren betrug 0,5. 8 Patienten (23%) waren verstorben. Schlussfolgerung: Das System verkuerzt oder ersetzt die lokale Lyse. Vergleichbar ist der Hydrolyser {sup trademark} nur mit dem SET-Thrombektomiesystem {sup trademark}, wobei den Autoren die laterale Absaugoeffnung guenstiger erscheint, um murale Thromben zu entfernen. (orig.)

Beyer-Enke, S.A.; Deichen, J.; Zeitler, E. [Staedtisches Klinikum Nuernberg-Nord (Germany). Inst. fuer Diagnostische und interventionelle Radiologie

1999-08-01

223

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

224

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

1984-01-01

225

Effects of Selected Assay Parameters on Measurement of Lignocellulose Mineralization with a Radiolabeled Substrate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Varying the amount of labeled substrate or the amount of leaf material resulted in significant nonlinear changes in lignocellulose mineralization, as measured with natural [14C]lignin-labeled lignocellulose. The use of periodic rather than continuous aeration was found not to have significant effects on measured mineralization.

Baker, Katherine H.

1983-01-01

226

Desalting Fish Skin Protein Hydrolysates Using Macroporous Adsorption Resin  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Macroporous Adsorption Resin (MAR) DA 201-C was used to desalt different Fish Skin Protein Hydrolysates (FSPHs). The FSPHs were obtained by hydrolysis of fish skin using Alcalase in a batch reactor a 60°C and pH 8.25. The ash was removed by adsorbing FSPHs onto MAR. Desorption was achieved by washing with alcohol at different concentrations. Ash content of the FSPHs was reduced from 4.69-5.57 to 1.07-2.48% range. The protein content was enriched from 89.07-90.82 to 94.89-96.38% range. MAR ha...

Joseph Wasswa; Jian Tang; Xiao-Hong Gu

2007-01-01

227

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

228

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.)

1975-01-01

229

Spent fuel shipping cask  

International Nuclear Information System (INIS)

The invention discloses a shipping cask for spent or failed nuclear fuel assemblies, having 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

1975-01-01

230

Adhesion improvement of lignocellulosic products by enzymatic pre-treatment.  

Science.gov (United States)

Enzymatic bonding methods, based on laccase or peroxidase enzymes, for lignocellulosic products such as medium-density fiberboard and particleboard are discussed with reference to the increasing costs of presently used petroleum-based adhesives and the health concerns associated with formaldehyde emissions from current composite products. One approach is to improve the self-bonding properties of the particles by oxidation of their surface lignin before they are fabricated into boards. Another method involves using enzymatically pre-treated lignins as adhesives for boards and laminates. The application of this technology to achieve wet strength characteristics in paper is also reviewed. PMID:18502077

Widsten, Petri; Kandelbauer, Andreas

2008-01-01

231

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

232

Process for Production of Hydrolysed Collagen from Agriculture Resources: Potential for Further Development  

Directory of Open Access Journals (Sweden)

Full Text Available Collagen is not a uniform substance, but is rather a family of protein. It is a group of naturally occurring proteins found in animals, especially in the flesh and connective tissues of mammals. For food or nutritional purpose, collagen is broken down into gelatine which can be broken down further into hydrolysed collagen. Hydrolysed collagen is a polypeptide composite made by further hydrolysis of denatured collagen or gelatin and the molecular weights are within the range approximately 500 to 25000 Da. In hydrolysate, the molecular mass and the size of the molecules have been deliberately decreased by hydrolysis part of peptide bonds of the gelatine molecules. This will make the hydrolysed collagen dissolved in cold water and does not gel anymore but still has surface active properties. The processes involved in processing hydrolysed collagen are demineralization, extraction of collagen to gelatine, enzymatic hydrolysis to obtain hydrolysed collagen, ion exchange, filtration, evaporation, sterilization and finally drying. In previous study a large number of studies focused on the enzymatic hydrolysis of collagen or gelatine for the production of bioactive peptide. However, studies focusing on the process development of hydrolysed collagen are still limited. This study thus will briefly describe the process design, market potential, research and development work and potential future research development for the production of hydrolysed collagen from agriculture sources such as cattle bones, fish skins and fish scales.

Abdul Wahab Mohammad

2014-01-01

233

Production of Defatted Palm Kernel Cake Protein Hydrolysate as a Valuable Source of Natural Antioxidants  

Directory of Open Access Journals (Sweden)

Full Text Available 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.

Mohammad Zarei

2012-06-01

234

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

235

Spent fuel management in Japan  

International Nuclear Information System (INIS)

The numbers of current nuclear electric generation together with spent fuel arising are updated and their future predictions are made. Spent fuel discharged from LWRs is now stored at reactor sites, waiting for being reprocessed in the future. Meanwhile, it is pointed out that the interim spent fuel storage facility should be constructed and commissioned by around 2010, to accommodate superfluous spent fuel from nuclear power stations. Recovered plutonium is currently scheduled to be used in LWRs as MOX fuel and ultimately to be burned in FBRs in accordance with the Long-Term Programme for Research, Development and Utilization of Nuclear Energy. (author)

1999-07-01

236

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

237

Efficient production of pullulan using rice hull hydrolysate by adaptive laboratory evolution of Aureobasidium pullulans.  

Science.gov (United States)

Pullulan production by Aureobasidium pullulans CCTCC M 2012259 using rice hull hydrolysate as the carbon source was conducted. The acetic acid in the hydrolysate was demonstrated to exert a negative effect on pullulan biosynthesis. Instead of employing expensive methods to remove acetic acid from the hydrolysate, a mutant A. pullulans ARH-1 was isolated following 20 cycles of adaptive laboratory evolution of the parental strain on medium containing acetic acid. The maximum pullulan production achieved by the adapted mutant at 48h using the hydrolysate of untreated rice hull was 22.2gL(-1), while that obtained by the parental strain at 60h was 15.6gL(-1). The assay of key enzymes associated with pullulan biosynthesis revealed that acetic acid inhibited enzyme activity rather than suppressing enzyme synthesis. These results demonstrated that adaptive evolution highly improved the efficiency of pullulan production by A. pullulans using the hydrolysate of untreated rice hull. PMID:24835913

Wang, Dahui; Ju, Xiaomin; Zhou, Donghai; Wei, Gongyuan

2014-07-01

238

Spent fuel management in Ukraine and spent fuel data tracking  

International Nuclear Information System (INIS)

Ukraine has eleven WWER-1000 and two WWER-440 operating reactors at four nuclear plants. These reactors generated almost 45% of Ukraine's electricity. The last of the three RBMK-1000 reactors of Chornobyl NPP was shut down on December 15, 2000. Two WWER-1000 units (one at Khmelnytskyy NPP and another at Rivne NPP) are under construction. According to the Spent Fuel Management Program of Ukraine, which was approved in 2000, the state policy in the spent fuel management field is 'wait and see'. In order to implement this state policy the following problems should be solved: Construction of interim spent fuel storage facilities; Provision of spent fuel transportation from the reactor site to the interim storage facility; Provision of scientific and technical support of the spent fuel management. (author)

2006-11-01

239

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 37Ë?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

240

SO{sub 2}-Ethanol-Water fractionation of lignocellulose and pilot scale production of Isopropanol-Butanol-Ethanol solvent mixture with an advanced column technology - SEWIBE  

Energy Technology Data Exchange (ETDEWEB)

The overall objective is to demonstrate at the pilot scale level the production of biofuels from lignocellulose biomass using the omnivorous SO{sub 2}-ethanol-water (SEW) fractionation process and an advanced column fermentation technology. A monomeric hemicellulose sugar solution will be produced by conditioning the spent fractionation liquor and a glucose solution by subsequent hydrolysis of the liberated cellulosic fibers. The combined monomeric sugars streams containing hexoses and pentoses will be fermented to a mixture of isopropanol, n-butanol and ethanol (IBE solvents) using genetically modified Clostridium bacteria. The recovery yields of the cooking chemicals, i.e. ethanol and unreacted SO{sub 2} from the spent fractionation liquor by evaporation and steam stripping will be established. Soluble and precipitated lignin fractions of the spent liquor combined with the organic residue remaining after solvent-solvent extraction of the IBE solvents will be studied experimentally with the objective to establish their potential as commercial products and biofuels, and the total sulphur recovery yield of these biomass fractions. (orig.)

Heiningen, A. van (Aalto Univ., Espoo (Finland), Dept. of Forest Products Technology), e-mail: adriaan.vanheiningen@aalto.fi; Granstroem, T. (Aalto Univ., Espoo (Finland), Dept.of Biotechnology and Chemical Technology), e-mail: tom.granstrom@aalto.fi

2011-11-15

 
 
 
 
241

Furfural--a promising platform for lignocellulosic biofuels.  

Science.gov (United States)

Furfural offers a promising, rich platform for lignocellulosic biofuels. These include methylfuran and methyltetrahydrofuran, valerate esters, ethylfurfuryl and ethyltetrahydrofurfuryl ethers as well as various C(10)-C(15) coupling products. The various production routes are critically reviewed, and the needs for improvements are identified. Their relative industrial potential is analysed by defining an investment index and CO(2) emissions as well as determining the fuel properties for the resulting products. Finally, the most promising candidate, 2-methylfuran, was subjected to a road trial of 90,000 km in a gasoline blend. Importantly, the potential of the furfural platform relies heavily on the cost-competitive production of furfural from lignocellulosic feedstock. Conventional standalone and emerging coproduct processes-for example, as a coproduct of cellulosic ethanol, levulinic acid or hydroxymethyl furfural-are expensive and energetically demanding. Challenges and areas that need improvement are highlighted. In addition to providing a critical review of the literature, this paper also presents new results and analysis in this area. PMID:22213717

Lange, Jean-Paul; van der Heide, Evert; van Buijtenen, Jeroen; Price, Richard

2012-01-01

242

Ethanol Production from Lignocellulose by the Dimorphic Fungus Mucor Indicus  

Energy Technology Data Exchange (ETDEWEB)

Ethanol production from dilute-acid lignocellulosic hydrolyzate by the dimorphic fungus Mucor indicus was investigated. A mixture of different forest wood chips dominated by spruce was hydrolyzed with 0.5 g/L sulfuric acid at 15 bar for 10 min, yielding different sugars including galactose, glucose, mannose, and xylose, but also different fermentation inhibitors such as acetic acid, furfural, hydroxymethyl furfural (HMF), and phenolic compounds. We induced different morphological growth of M. indicus from purely filamentous, mostly filamentous, mostly yeast-like to purely yeast-like. The different forms were then used to ferment the hydrolyzate. They tolerated the presence of the inhibitors under anaerobic batch cultivation well and the ethanol yield was 430-440 g/kg consumed sugars. The ethanol productivity depended on the morphology. Judging from these results, we conclude that M. indicus, is useful for ethanol production from toxic substrates independent of its morphology. Keywords: bio-ethanol, lignocellulosic materials, dilute acid hydrolysis, Mucor indicus, dimorphic fungi

Lennartsson, P.R.; Taherzadeh, M.J. (School of Engineering, Univ. of Boraas, SE-50190, Boraas (Sweden)). e-mail: Patrik.Lennartsson@hb.se; Karimi, K. (Dept. of Chemical Engineering, Isfahan Univ. of Technology, 84156-83111, Isfahan (IR)); Edebo, L. (Dept. of Clinical Bacteriology, Univ. of Goeteborg, SE-41346, Goeteborg (Sweden))

2008-10-15

243

Development of a Commerical Enzyme System for Lignocellulosic Biomass Saccharification  

Energy Technology Data Exchange (ETDEWEB)

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

Manoj Kumar, PhD

2011-02-14

244

The potential of lignocellulosic ethanol production in the Mediterranean Basin  

Energy Technology Data Exchange (ETDEWEB)

This review provides an overview of the potential of bioethanol fuel production from lignocellulosic residues in the Mediterranean Basin. Residues from cereal crops, olive trees, and tomato and grape processing are abundant lignocellulosic wastes in France, Italy, Spain, Turkey and Egypt, where their use as raw materials for ethanol production could give rise to a potential production capacity of 13 Mtoe of ethanol. Due to the lack of sufficient amounts of agricultural residues in all of the other Mediterranean countries, use of the cellulosic content of municipal solid waste (MSW) as feedstock for ethanol fuel production is also proposed. A maximum potential production capacity of 30 Mtoe of ethanol could be achieved from 50% of the 180 million tons of waste currently produced annually in the Mediterranean Basin, the management of which has become a subject of serious concern. However, to make large-scale ethanol production from agricultural residues and MSW a medium-term feasible goal in the Mediterranean Basin, huge efforts are needed to achieve the required progress in cellulose ethanol technologies and to overcome several foreseeable constraints. (author)

Faraco, Vincenza [Department of Organic Chemistry and Biochemistry, University of Naples ' ' Federico II' ' , Naples (Italy); School of Biotechnological Sciences, University of Naples ' ' Federico II' ' , Naples (Italy); Hadar, Yitzhak [Department of Microbiology and Plant Pathology, The Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, Rehovot (Israel)

2011-01-15

245

Covalent immobilization of ?-glucosidase on magnetic particles for lignocellulose hydrolysis.  

Science.gov (United States)

?-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. PMID:23371782

Alftrén, Johan; Hobley, Timothy John

2013-04-01

246

Fuel ethanol production from agricultural lignocellulosic feedstocks - a review  

Energy Technology Data Exchange (ETDEWEB)

Over the past three decades significant efforts have been made towards the conservation of fossil-based fuels and the exploration and exploitation of new renewable sources. The focus primarily has been on the outlook for alternatives to the petroleum products. In this spectrum alcohol manufacture from biomass has attracted great attention all over the world which could be used as an alternative source to petrol or in blends with petrol. The National Research Council (NRC) has substantially emphasized the reduction of CO[sub 2] emissions and the other so-called greenhouse gases. The NRC committee also recommends better evaluations of the processes for converting the biomass/lignocellulosic wastes to ethanol that will lessen the US dependence on foreign oil. Among the factors behind the move to bio-based materials are the environmental concerns, the availability of abundant, renewable agricultural and forest resources that are both inexpensive and under-utilized. This paper provides a comprehensive review of the ethanol fermentation from the food crops as well as the lignocellulosic materials. Different processes involved including acid and enzymatic hydrolysis, enzyme production, fermentation, and lignin conversion are discussed. Also the energy balance considerations of the process are elucidated. 46 refs., 14 figs., 1 tab.

Bashir, S.; Lee, S. (University of Akron, Akron, OH (United States). Dept. of Chemical Engineering)

1994-01-01

247

A method for rapid determination of sugars in lignocellulose prehydrolyzate  

Directory of Open Access Journals (Sweden)

Full Text Available 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 be quantified. It was found that the derivatives from these two different sugars have an isosbestic point at 425 nm. According to the validation results, high accuracy and reasonable recovery rate is shown with the present method (pentoses recovery 97.1 to 100.0%, hexoses recovery 97.2 to 102.0%. Additionally, the interferences from substances including lignin, furfural, 5-hydroxymethyl furfural (HMF, glucuronic acid, and galacturonic acid are insignificant. All of the above results illustrate the suitability of this method for analyzing sugars in the lignocelluloses prehydrolyzate, especially hardwoods or herbaceous plants, based on forest-related biorefinery research.

Congcong Chi

2013-02-01

248

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)

1998-03-01

249

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

2012-01-01

250

Conversion of lignocellulosic biomass by irradiation: use of high-performance liquid chromatography for study  

International Nuclear Information System (INIS)

Irradiation of lignocellulosic material is under investigation as one means of converting biomass to useful chemical feedstocks and/or fermentable substrates. High-energy gamma radiation in combination with various chemical treatments effects degradation of lignocellulosic and cellulosic materials. The composition of the generated products has been monitored for carbohydrates and organic acids by high-performance liquid chromatography (HPLC). Comparisons of the extent and products of decomposition of the cellulose component of the lignocellulosic materials are presented. 15 references, 6 figures, 2 tables

1982-05-24

251

Pilot-scale ethanol production from rice straw hydrolysates using xylose-fermenting Pichia stipitis.  

Science.gov (United States)

Ethanol was produced at pilot scale from rice straw hydrolysates using a Pichia stipitis strain previously adapted to NaOH-neutralized hydrolysates. The highest ethanol yield was 0.44 ± 0.02 g(p)/g(s) at an aeration rate of 0.05 vvm using overliming-detoxified hydrolysates. The yield with hydrolysates conditioned by ammonia and NaOH was 0.39 ± 0.01 and 0.34 ± 0.01 g(p)/g(s), respectively, were achieved at the same aeration rate. The actual ethanol yield from hydrolysate fermentation with ammonia neutralization was similar to that with overliming hydrolysate after taking into account the xylose loss resulting from these conditioning processes. Moreover, the ethanol yield from ammonia-neutralized hydrolysates could be further enhanced by increasing the initial cell density by two-fold or reducing the combined concentration of furfural and 5-hydroxymethyl furfural to 0.6g/L by reducing the severity of operational conditions in pretreatment. This study demonstrated the potential for commercial ethanol production from rice straw via xylose fermentation. PMID:22537402

Lin, Ting-Hsiang; Huang, Chiung-Fang; Guo, Gia-Luen; Hwang, Wen-Song; Huang, Shir-Ly

2012-07-01

252

Factors causing compositional changes in soy protein hydrolysates and effects on cell culture functionality.  

Science.gov (United States)

Soy protein hydrolysates significantly enhance cell growth and recombinant protein production in cell cultures. The extent of this enhancement in cell growth and IgG production is known to vary from batch to batch. This can be due to differences in the abundance of different classes of compounds (e.g., peptide content), the quality of these compounds (e.g., glycated peptides), or the presence of specific compounds (e.g., furosine). These quantitative and qualitative differences between batches of hydrolysates result from variation in the seed composition and seed/meal processing. Although a considerable amount of literature is available that describes these factors, this knowledge has not been combined in an overview yet. The aim of this review is to identify the most dominant factors that affect hydrolysate composition and functionality. Although there is a limited influence of variation in the seed composition, the overview shows that the qualitative changes in hydrolysate composition result in the formation of minor compounds (e.g., Maillard reaction products). In pure systems, these compounds have a profound effect on the cell culture functionality. This suggests that the presence of these compounds in soy protein hydrolysates may affect hydrolysate functionality as well. This influence on the functionality can be of direct or indirect nature. For instance, some minor compounds (e.g., Maillard reaction products) are cytotoxic, whereas other compounds (e.g., phytates) suppress protein hydrolysis during hydrolysate production, resulting in altered peptide composition, and, thus, affect the functionality. PMID:24117369

Gupta, Abhishek J; Gruppen, Harry; Maes, Dominick; Boots, Jan-Willem; Wierenga, Peter A

2013-11-13

253

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

254

Antioxidant activities of red tilapia (Oreochromis niloticus) protein hydrolysates as influenced by thermolysin and alcalase  

Science.gov (United States)

The hydrolysis process was performed on fish meat from Red Tilapia (Oreochromis niloticus) by enzymes thermolysin and alcalase under optimum conditions. The hydrolysis was performed from 0 - 4 hours at 37°C. Hydrolysates after 2 hours incubation with thermolysin and alcalase had degree of hydrolysis of 76.29 % and 63.49 %, respectively. The freeze dried protein hydrolysate was tested for peptide content and characterized with respect to amino acid composition. The result of increased peptide content in Red Tilapia (O. Niloticus) hydrolysates obtained was directly proportional to the increase activities of different proteolytic enzymes. The result of amino acid composition showed that the sample used contained abundant Gly, Ala, Asp, Glu, Lys and Leu in residues or peptide sequences. Both enzymatic hydrolysates were tested for anti-oxidant activity with DPPH and ABTS assay. Alcalase yielded higher anti-oxidative activity than Thermolysin hydrolysates after 1 hour incubation, but both enzymes hydrolysates showed a significant decrease of anti-oxidant activity after 2 hours of incubation. Hydrolysates from Red Tilapia may contribute as a health promoting ingredient in functional foods to reduce oxidation stress caused by accumulated free radicals.

Daud, Nur'Aliah; Babji, Abdul Salam; Yusop, Salma Mohamad

2013-11-01

255

Cellulosic ethanol: progress towards a simulation model of lignocellulosic biomass;  

Energy Technology Data Exchange (ETDEWEB)

A CHARMM molecular mechanics force field for lignin is derived. Parameterization is based on reproducing quantum mechanical data of model compounds. Partial atomic charges are derived by the examination of methoxybenzene:water interactions. Dihedral parameters are optimized by fitting to critical rotational potentials, and bonded parameters are obtained by optimizing vibrational frequencies and normal modes. The force field is validated by performing a molecular dynamics simulation of a crystal of a lignin fragment molecule and comparing simulation-derived structural features with experimental results. Together with the existing force field for polysaccharides, this work will enable full simulations of lignocellulose. This work presents a molecular mechanics force field for lignin that is compatible with the CHARMM potential energy function. The parameterization was based on reproducing quantum-mechanically derived target data. Special care was taken to correctly describe the most common lignin linkage: the {beta}-O-4{prime} bond. The partial atomic charge of the oxygen and carbon atoms participating in the linkage were derived by examining interactions between a lignin fragment model compound and a water molecule. Dihedral parameters were obtained by reproducing QM potential energy profiles, with emphasis placed on reproducing accurately the thermally sampled low energy regions. The remaining bond and angle parameters were derived using the AFMM method. In order to test the validity of the force field a simulation of a lignin-dimer crystal was performed. The overall good agreement between the structural properties of the MD run and the experiment provide confidence that the force field can be used in simulation of biomass. The accurate computer simulation of lignin in lignocellulose will present significant challenges. Unlike many biological macromolecules that have been studied with molecular simulation, both the chemical and three-dimensional structures of lignin are relatively poorly researched. However, the present force field provides a basis for constructing molecular models of lignin systems, and, in combination with a range of biophysical measurements, significant progress in determining structures of lignocellulosic biomass can be expected in the near future.

Petridis, Loukas [ORNL; Smith, Jeremy C [ORNL

2008-01-01

256

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

257

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)

1999-08-01

258

In vitro Antioxidant Activities of Trianthema portulacastrum L. Hydrolysates  

Science.gov (United States)

Hydrolysates of Trianthema portulacastrum in acidified methanol were evaluated for their total phenolic (TP) constituents and respective antioxidant activities using in vitro assays (i.e., 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, percent inhibition of linoleic acid peroxidation, and ferric reducing power). The observed results indicate that root, shoot, and leaf fractions of T. portulacastrum contain 50.75~98.09 mg gallic acid equivalents/g dry weight of TP. In addition, these fractions have substantial reducing potentials (0.10~0.59), abilities to inhibit peroxidation (43.26~89.98%), and DPPH radical scavenging capabilities (6.98~311.61 ?g/mL IC50). The experimental data not only reveal T. portulacastrum as potential source of valuable antioxidants, but also indicate that acidified methanol may be an ideal choice for the enhanced recovery of phenolic compounds with retained biological potential for the food and pharmaceutical industry.

Yaqoob, Sadaf; Sultana, Bushra; Mushtaq, Muhammad

2014-01-01

259

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

260

Effect of protein hydrolysate on the degradation of diesel fuel in soil*  

Science.gov (United States)

The addition of protein hydrolysate solution to soil contaminated with diesel fuel was investigated for effects on diesel degradation. The application of protein hydrolysate solution led to an increase in the removal of diesel from the soil. At the end of the 21d experimental period the amount of diesel removed from the soil was 21% greater with the addition of protein hydrolysate solution when compared to a control system. This increased removal was linked to increases in both the number of hydrocarbon degrading micro-organisms, and an extension to their period of activity. PMID:10713212

Harrison; Ripley; Dart; Betts; Wilson

2000-03-01

 
 
 
 
261

Effect of hydrolysed egg protein on brain tryptophan availability.  

Science.gov (United States)

Serotonin synthesis critically depends on plasma levels of tryptophan (TRP). Earlier studies have shown that for mood and cognitive benefits to occur, the ratio between TRP and other large neutral amino acids (LNAA) has to be increased by approximately 40 %. The present study investigated the dose-dependent effects of a TRP-rich hydrolysed protein (egg-protein hydrolysate, EPH) on the plasma TRP:LNAA. Moreover, it was investigated whether EPH could increase TRP:LNAA in the presence of 2 g of milk protein (MP). In a randomised double-blind crossover design, plasma amino acids were measured every 30 min for 3·5 h after ingestion of a drink containing either three different doses of 4, 8 and 12 g EPH containing 270, 560 or 800 mg of TRP, respectively, the combination of 4 g EPH and 2 g MP (74 mg TRP), or 4 g MP (148 mg TRP) in twenty healthy subjects with a mean age of 52 years. All three EPH doses caused significant increases of TRP:LNAA above 40 % at 30, 60 and 90 min after consumption in a dose-dependent manner. Compared with the 4 g EPH, the increase in TRP:LNAA in the 4 g EPH with 2 g MP condition was significantly lower at 60 min (63 v. 44 %, P 0·05). The present study showed that a low dose of 4 g EPH with even the addition of 2 g MP was sufficient to increase the ratio of TRP:LNAA above 40 %. Thus, EPH offers a viable ingredient to increase TRP availability. PMID:21269547

Mitchell, E Siobhan; Slettenaar, Marieke; Quadt, Frits; Giesbrecht, Timo; Kloek, Joris; Gerhardt, Cindy; Bot, Arjen; Eilander, Ans; Wiseman, Sheila

2011-02-01

262

Biorefining of lignocellulosic feedstock--Technical, economic and environmental considerations.  

Science.gov (United States)

Biorefinery, an example of a multiple products system, integrates biomass conversion processes and equipment to produce fuels, power and chemicals from biomass. This study focuses on technical design, economic and environmental analysis of a lignocellulosic feedstock (LCF) biorefinery producing ethanol, succinic acid, acetic acid and electricity. As the potential worldwide demand of succinic acid and its derivatives can reach 30 million tons per year, succinic acid is a promising high-value product if production cost and market price are substantially lowered. The results of the economic analysis show that the designed refinery has great potentials compared to the single-output ethanol plant; even when the price of succinic acid is lowered or the capital investment doubled. In terms of eco-efficiency, the LCF biorefinery shows better environmental performances mainly in global warming potential due to CO(2) fixation during acid fermentation. The overall evaluation of the eco-efficiency depends on the importance attached to each impact category. PMID:20093018

Luo, Lin; van der Voet, Ester; Huppes, Gjalt

2010-07-01

263

Fuel lignocellulosic briquettes, die design and products study  

Energy Technology Data Exchange (ETDEWEB)

Briquetting of biomass can be done through various techniques. The present work describes the process of designing a taper die and its optimisation for use in a hydraulic machine. The application of an experimental design technique, and the later statistical analysis of the results is presented, applied to a laboratory hydraulic press densification process of lignocellulosic biomass. The most appropriate experiment type is determined for a first set of experiments; calculating, among other things: minimum number of tests to carry out to obtain binding conclusions, most influential factors, and search paths to improve fuel quality. Another experiment type is determined for a second set of experiments, taking account of the most influential factors (pressure, temperature and moisture content), and also the number of tests to carry out considering the improvement of density and friability. Finally, an approximation study of the best product allows conclusions to be reached on product behaviour beyond the experimental design range factors. (Author)

Granada, E.; Miguez, J.L.; Moran, J. [Vigo Univ. (Spain). E.T.S. Ingenieros Industriales y Minas; Lopez Gonzalez, L.M. [Universidad de La Rioja (Spain). Departamento de Ingenieria Mecanica

2002-12-01

264

Enzymatic hydrolysis and ethanol fermentation of lignocellulosic materials  

Energy Technology Data Exchange (ETDEWEB)

The kinetics of enzymatic hydrolysis of different lignocellulosic materials (wheat straw, newspaper and microcrystalline cellulose Avicel PH 101) was studied using the cellulase complexes from Trichoderma reesei QM 9414 and its mutants M 5, M 6, MHC 15 and MHC 22. The maximum yields of hydrolysis were obtained with wheat straw partially delignified with 1% NaOH as substrate, and using the enzyme from the mutants T. reesei M 6 and MHC 22. The possibility of simultaneous enzymatic hydrolysis and ethanol fermentation of wheat straw using the enzyme complex from M6 and yeasts of the genus Candida and Torulopsis was also investigated. A good conversion of liberated glucose and cellobiose to ethanol was obtained, however, xylose was not fermented. (Refs. 21).

Danielova, E.; Farkas, V.; Bauer, S.

1983-01-01

265

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

266

Lab-scale Technology for Biogas Production from Lignocellulose Wastes  

Directory of Open Access Journals (Sweden)

Full Text Available Currently-operating biogas plants are based on the treatment of lignocellulose biomass, which is included in materials such as agriculture and forestry wastes, municipal solid wastes, waste paper, wood and herbaceous energy crops. Lab-scale biogas technology was specially developed for evaluating the anaerobic biodegrability and the specific methane yields of solid organic substrates. This technology falls into two main categories – pretreatment equipments, and fermentation equipments. Pretreatment units use physical principles based on mechanical comminution (ball mills, macerator orhydrothermal treatment (liquid hot water pretreatment technology. The biochemical methane potential test is used to evaluate the specific methane yields of treated or non-treated organic substrates. This test can be performed both by lab testing units and by lab fermenter.

LukᚠKrátký

2012-01-01

267

Ranking of lignocellulosic biomass pellets through multicriteria modeling  

Energy Technology Data Exchange (ETDEWEB)

A study was conducted in which pellets from different lignocellulosic biomass sources were ranked using a multicriteria assessment model. Five different pellet alternatives were compared based on 10 criteria. The pair-wise comparison was done in order to develop preference indices for various alternatives. The methodology used in this study was the Preference Ranking Organization Method for Enrichment and Evaluation (PROMETHEE). The biomass included wood pellets, straw pellets, switchgrass pellets, alfalfa pellets and poultry pellets. The study considered both quantitative and qualitative criteria such as energy consumption to produce the pellets, production cost, bulk density, NOx emissions, SOx emissions, deposit formation, net calorific value, moisture content, maturity of technology, and quality of material. A sensitivity analysis was performed by changing weights of criteria and threshold values of the criteria. Different scenarios were developed for ranking cost and environmental impacts. According to preliminary results, the wood pellet is the best energy source, followed by switchgrass pellets, straw pellets, alfalfa pellets and poultry pellets.

Sultana, A.; Kumar, A. [Alberta Univ., Edmonton, AB (Canada). Dept. of Mechanical Engineering

2009-07-01

268

Radicalization of lignocellulosic fibers, related structural and morphological changes.  

Science.gov (United States)

The radicalization of unbleached lignocellulosic fibers obtained from thermomechanical (TMP) and chemothermomechanical (CTMP) pulps was performed in heterogeneous phase by reaction with dioxygen in the presence of N,N'-ethylenebis(salicylideneiminato)cobalt(II), [Co(salen)], as catalyst. Phenoxy cobalt radicals immobilized in fibers were observed by electron paramagnetic resonance (EPR) spectroscopy; their amount depends on the fiber swelling induced by reaction medium. The absolute concentration of such radicals in fibers, about 10(16) spin/g, reaches values 10 times higher than that of phenoxy radicals formed in similar oxidative reactions catalyzed by laccase. The generation of phenoxy cobalt radicals in fibers was related to structural changes of lignin units, detected by mono- and bidimensional nuclear magnetic resonance ((13)C NMR and 2D-HSQC) investigations, and to morphological modifications in fibers observed by scanning electron microscopy (SEM). PMID:15877382

Canevali, Carmen; Orlandi, Marco; Zoia, Luca; Scotti, Roberto; Tolppa, Eeva-Liisa; Sipila, Jussi; Agnoli, Francesca; Morazzoni, Franca

2005-01-01

269

Simultaneous uptake of lignocellulose-based monosaccharides by Escherichia coli.  

Science.gov (United States)

Lignocellulosic waste is a naturally abundant biomass and is therefore an attractive material to use in second generation biorefineries. Microbial growth on the monosaccharides present in hydrolyzed lignocellulose is however associated with several obstacles whereof one is the lack of simultaneous uptake of the sugars. We have studied the aerobic growth of Escherichia coli on D-glucose, D-xylose, and L-arabinose and for simultaneous uptake to occur, both the carbon catabolite repression mechanism (CCR) and the AraC repression of xylose uptake and metabolism had to be removed. The strain AF1000 is a MC4100 derivative that is only able to assimilate arabinose after a considerable lag phase, which is unsuitable for commercial production. This strain was successfully adapted to growth on L-arabinose and this led to simultaneous uptake of arabinose and xylose in a diauxic growth mode following glucose consumption. In this strain, a deletion in the phosphoenolpyruvate:phosphotransferase system (PTS) for glucose uptake, the ptsG mutation, was introduced. The resulting strain, PPA652ara simultaneously consumed all three monosaccharides at a maximum specific growth rate of 0.59?h(-1) , 55% higher than for the ptsG mutant alone. Also, no residual sugar was present in the cultivation medium. The potential of PPA652ara is further acknowledged by the performance of AF1000 during fed-batch processing on a mixture of D-glucose, D-xylose, and L-arabinose. The conclusion is that without the removal of both layers of carbon uptake control, this process results in accumulation of pentoses and leads to a reduction of the specific growth rate by 30%. PMID:24382675

Jarmander, Johan; Hallström, Björn M; Larsson, Gen

2014-06-01

270

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

271

WWER spent fuel storage  

International Nuclear Information System (INIS)

Selection criteria for PAKS NPP dry storage system are outlined. They include the following: fuel temperature in storage; sub-criticality assurance (avoidance of criticality for fuel in the unirradiated condition without having to take credit for burn-up); assurance of decay heat removal; dose uptake to the operators and public; protection of environment; volume of waste produced during operation and decommissioning; physical protection of stored irradiated fuel assemblies; IAEA safeguards assurance; storage system versus final disposal route; cost of construction and extent of technology transfer to Hungarian industry. Several available systems are evaluated against these criteria, and as a result the GEC ALSTHOM Modular Vault Dry Store (MVDS) system has been selected. The MVDS is a passively cooled dry storage facility. Its most important technical, safety, licensing and technology transfer characteristics are outlined. On the basis of the experience gained some key questions and considerations related to the East European perspective in the field of spent fuel storage are discussed. 8 figs

1994-09-07

272

Study of the formation of polyethylene composites and lignocellulose materials by means of irradiation and extrusion  

International Nuclear Information System (INIS)

One of the greatest opportunities for using of biomass as a precursor in the production of polymeric materials is the lignocellulose composites that can combine high performance with low costs. This work is a initial study on the production of a lignocellulose reinforced polyethylene composite. A compatibilization made by a induced gamma radiation grafting reaction was used to increase the adhesion between the matrix and the reinforced or filled fibers. The lignocellulose materials were exposed to gamma radiation in order to promote a molecular degradation and increase its reactivity. The polymer, the lignocellulose material and the compatibilization were processed by extrusion and the composite produced by this process were characterized by mechanical tests. (author)

2000-10-05

273

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

274

Environmentally-friendly sonochemistry synthesis of hybrids from lignocelluloses and silver.  

Science.gov (United States)

The purpose of this study was to explore a green strategy about the high value-added applications of biomass. Hybrids from lignocelluloses and silver have been successfully prepared using NaBH4 as reducing reagent by an environmentally-friendly sonochemistry method. The phase, microstructure, and morphology of the hybrids were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). The influences of the various reaction parameters including reaction time, lignocelluloses concentration, and types of reducing reagents on the products were investigated in detail. Silver particles can be better dispersed on the lignocelluloses matrix by adjusting reaction parameters. These hybrids may be a promising antimicrobial material for their applications in the biomedical field. This environmentally-friendly synthetic strategy reported here opens a new window to the high value-added applications of lignocelluloses. PMID:24507304

Dong, Yan-Yan; Li, Shu-Ming; Ma, Ming-Guo; Zhao, Jin-Jin; Sun, Run-Cang; Wang, Shan-Peng

2014-02-15

275

Intermodal transportation of spent fuel  

International Nuclear Information System (INIS)

Concepts for transportation of spent fuel in rail casks from nuclear power plant sites with no rail service are under consideration by the US Department of Energy in the Commercial Spent Fuel Management program at the Pacific Northwest Laboratory. This report identifies and evaluates three alternative systems for intermodal transfer of spent fuel: heavy-haul truck to rail, barge to rail, and barge to heavy-haul truck. This report concludes that, with some modifications and provisions for new equipment, existing rail and marine systems can provide a transportation base for the intermodal transfer of spent fuel to federal interim storage facilities. Some needed land transportation support and loading and unloading equipment does not currently exist. There are insufficient shipping casks available at this time, but the industrial capability to meet projected needs appears adequate

1983-01-01

276

Spent Fuel Integrity During Transportation.  

Science.gov (United States)

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 int...

C. W. Funk L. D. Jacobson

1980-01-01

277

Spent fuel element storage facility  

International Nuclear Information System (INIS)

Purpose: To always keep water level of a spent fuel cask pit equal with water level of spent fuel storage pool by means of syphon principle. Constitution: The pool water of a spent fuel storage pool is airtightly communicated through a pipe with the pool water of a spent fuel cask, and a gate is provided between the pool and the cask. Since cask is conveyed into the cask pit as the gate close while conveying, the pool water level is raised an amount corresponding to the volume of the cask, and water flow through scattering pipe and the communication pipe to the storage pool. When the fuel is conveyed out of the cask, the water level is lowered in the amount corresponding to the volume in the cask pit, and the water in the pool flow through the communication pipe to the cask pit. (Sekiya, K.)

1981-01-01

278

Intermodal transportation of spent fuel  

Energy Technology Data Exchange (ETDEWEB)

Concepts for transportation of spent fuel in rail casks from nuclear power plant sites with no rail service are under consideration by the US Department of Energy in the Commercial Spent Fuel Management program at the Pacific Northwest Laboratory. This report identifies and evaluates three alternative systems for intermodal transfer of spent fuel: heavy-haul truck to rail, barge to rail, and barge to heavy-haul truck. This report concludes that, with some modifications and provisions for new equipment, existing rail and marine systems can provide a transportation base for the intermodal transfer of spent fuel to federal interim storage facilities. Some needed land transportation support and loading and unloading equipment does not currently exist. There are insufficient shipping casks available at this time, but the industrial capability to meet projected needs appears adequate.

Elder, H.K.

1983-09-01

279

Adaptation of a flocculent Saccharomyces cerevisiae strain to lignocellulosic inhibitors by cell recycle batch fermentation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The ethanol production from lignocellulosic feedstocks is considered a promising strategy to increase global production of biofuels without impacting food supplies. However, some compounds released during the hydrolysis of lignocellulosic materials are toxic for the microbial metabolism, causing low ethanol yield and productivity during the fermentation. As an attempt to overcome this problem, the present study evaluated the adaptation of a flocculent strain of Saccharomyces cerevisiae (NRRL ...

2013-01-01

280

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

 
 
 
 
281

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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

282

Molecular Adaptation Mechanisms Employed by Ethanologenic Bacteria in Response to Lignocellulose-derived Inhibitory Compounds  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Current international interest in finding alternative sources of energy to the diminishing supplies of fossil fuels has encouraged research efforts in improving biofuel production technologies. In countries which lack sufficient food, the use of sustainable lignocellulosic feedstocks, for the production of bioethanol, is an attractive option. In the pre-treatment of lignocellulosic feedstocks for ethanol production, various chemicals and/or enzymatic processes are employed. These methods gene...

Ibraheem, Omodele; Ndimba, Bongani K.

2013-01-01

283

Catalytic upgrading of lignocellulose-derived platform molecules- Screening of homogeneous catalysts  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Lignocellulosic biomass has received widespread attention as environmentally benign feedstock for fuels. Biomass consists of cellulose, hemicellulose and lignin and has rather high oxygen content. Different techniques for the conversion of lignocellulose to liquid fuels have been suggested in the literature. In this thesis the emphasis is on the utilization of biomass-derived platform molecules. Platform molecules include eg. ketones, alcohols and carboxylic acids.

Nurttila, Sandra

2013-01-01

284

Engineering xylose metabolism in triacylglycerol-producing Rhodococcus opacus for lignocellulosic fuel production  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Background: There has been a great deal of interest in fuel productions from lignocellulosic biomass to minimize the conflict between food and fuel use. The bioconversion of xylose, which is the second most abundant sugar present after glucose in lignocellulosic biomass, is important for the development of cost effective bioprocesses to fuels. Rhodococcus opacus PD630, an oleaginous bacterium, accumulates large amounts of triacylglycerols (TAGs), which can be processed into advanced liquid...

Kurosawa, Kazuhiko; Wewetzer, Sandra J.; Sinskey, Anthony J.

2013-01-01

285

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 ...

Taherzadeh, Mohammad J.; Keikhosro Karimi

2008-01-01

286

Effect of steam explosion pre-treatment on enzymatic saccharification of lignocellulosic material  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Taking into account the sharp rise in prices and the depletion of resources of petroleum, an alternative to fossil resources is needed. A probable alternative is the use of lignocellulosic raw material to produce biofuels. The “first generation” biofuels are highly controversial because of the use of food plant material. The aim of the “second generation” biofuels is to take lignocellulosic non-food plant material as raw material.

Meyer, Laurence; Jacquet, Nicolas; Vanderghem, Caroline; Blecker, Christophe; Paquot, Michel

2011-01-01

287

Application of steam explosion for the pretreatment of the lignocellulosic raw materials  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Application of steam explosion for the pretreatment of the lignocellulosic raw materials. Steam explosion is a thermomechanochemical process which allows the breakdown of lignocellulosic structural components by steam heating, hydrolysis of glycosidic bonds by organic acid formed during the process and shearing forces due to the expansion of the moisture. The process is composed of two distinct stages: vapocracking and explosive decompression. Cumul effects of both phases include modification...

Jacquet, Nicolas; Vanderghem, Caroline; Blecker, Christophe; Paquot, Michel

2010-01-01

288

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 in...

Kristensen Jan B; Felby Claus; Jørgensen Henning

2009-01-01

289

Ethanol production from lignocellulosic biomass by recombinant Escherichia coli strain FBR5  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Lignocellulosic biomass, upon pretreatment and enzymatic hydrolysis, generates a mixture of hexose and pentose sugars such as glucose, xylose, arabinose and galactose. While Escherichia coli utilizes all these sugars it lacks the ability to produce ethanol from them. Recombinant ethanologenic E. coli strains have been created with a goal to produce ethanol from both hexose and pentose sugars. Herein, we review the current state of the art on the production of ethanol from lignocellulosic hydr...

Saha, Badal; Cotta, Michael A.

2012-01-01

290

Relationship between Calorific Value and Elementary Composition of Torrefied Lignocellulosic Biomass  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In this study, the relationship between calorific value and elementary composition of torrefied oil palm wastes (empty fruit bunches, mesocarp fiber and kernel shell) and other lignocellulosic biomass is discussed. Several correlations for calorific value vs. elementary composition for biomass were examined for their applicability to torrefied lignocellulosic biomass. One of the correlations was selected as the most appropriate for the purpose, based on average absolute error between observed...

Uemura, Y.; Omar, W.; Tsutsui, T.; Subbarao, D.; Yusup, S.

2010-01-01

291

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

292

Fast reactor spent fuel processing  

International Nuclear Information System (INIS)

The characteristics of fast reactor fuel and of the fuel cycle and specific problems of fast reactor fuel reprocessing are discussed. Wet and dry methods of spent fuel reprocessing are described and the two methods are compared. Reprocessing efforts in France, FRG, Great Britain, USSR, Italy, Japan, and Belgium are reviewed. The problem is briefly outlined of proliferation associated with spent fuel reprocessing. (J.P.)

1979-01-01

293

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

294

Hydrolysed walls in the water-conducting cells of Dendroligotrichum (bryophyta): Histochemistry and ultrastructure.  

Science.gov (United States)

Histochemical techniques and electron microscopy have been used to investigate the nature of the oblique primary end-walls of the water-conducting cells (hydroids) of Dendroligotrichum dendroides. (Hedw.) Broth. The observed properties (weakly birefringent; IKI-H2SO4-positive; periodic acid/Schiff negative; toluidine blue O-negative) support the conclusion that these end-walls are the cellulose residue of a primary wall that has been hydrolysed during autolysis of the hydroids. The walls are now referred to as hydrolysed end-walls. The unhydrolysed lateral-walls appear to be protected from hydrolytic attack by lignin or a lignin-like compound within those walls. The similarities between the hydrolysed end-walls of the hydroids and the hydrolysed walls of vascular plant tracheary elements are discussed. PMID:24458815

Scheirer, D C

1973-03-01

295

An integrated detoxification process with electrodialysis and adsorption from the hemicellulose hydrolysates of yellow poplars.  

Science.gov (United States)

An integrated detoxification process with electrodialysis (ED) followed by adsorption was performed to remove fermentation inhibitors from hemicellulose hydrolysates. The hydrolysates were prepared by oxalic acid pretreatment of yellow poplars at different temperatures. Of fermentation inhibitors, acetic acid showed high removal efficiency of about 90% and high transport rate during the ED process without membrane fouling. The integration of the detoxification processes increased up to the ethanol yield of 0.33g/g sugar, the ethanol production of about 9g/L, and the productivity of 0.12g/Lh, while the fermentation of non-detoxified hydrolysates did not produce bioethanol. The influence of inhibitor concentration on the fermentability showed that HMF had the highest inhibition effect. The results clearly showed that an integrated detoxification process with ED followed by adsorption removed fermentation inhibitors with high efficiency and increased the fermentability of the oxalic acid pretreated hemicellulose hydrolysates. PMID:24713602

Trinh, Ly Thi Phi; Kundu, Chandan; Lee, Jae-Won; Lee, Hong-Joo

2014-06-01

296

Spent Nuclear Fuel project, project management plan  

Energy Technology Data Exchange (ETDEWEB)

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

Fuquay, B.J.

1995-10-25

297

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

1992-01-01

298

Feather keratin hydrolysates obtained from microbial keratinases: effect on hair fiber  

Science.gov (United States)

Background Hair is composed mainly of keratin protein and a small amount of lipid. Protein hydrolysates, in particular those with low molecular weight distribution have been known to protect hair against chemical and environmental damage. Many types of protein hydrolysates from plants and animals have been used in hair and personal care such as keratin hydrolysates obtained from nails, horns and wool. Most of these hydrolysates are obtained by chemical hydrolysis and hydrothermal methods, but recently hydrolyzed hair keratin, feather keratin peptides, and feather meal peptides have been obtained by enzymatic hydrolysis using Bacillus spp in submerged fermentation. Results Keratin peptides were obtained by enzymatic hydrolysis of keratinases using Bacillus subtilis AMR. The microorganism was grown on a feather medium, pH 8.0 (1% feathers) and supplemented with 0.01% of yeast extract, for 5 days, at 28°C with agitation. The supernatant containing the hydrolysates was colleted by centrifugation and ultra filtered in an AMICON system using nano–membranes (Millipore – YC05). The Proteins and peptides were analyzed using HPTLC and MALDI-TOF-MS. Commercial preparations of keratin hydrolysates were used as a comparative standard. After five days the feather had been degraded (90-95%) by the peptidases and keratinases of the microorganism. MALDI-TOF mass spectrometry showed multiple peaks that correspond to peptides in the range of 800 to 1079 Daltons and the commercial hydrolysate was in the range of 900 to 1400 Da. HPTLC showed lower molecular mass peptides and amino acids in the enzymatic hydrolysate when compared with the commercial hydrolysate . A mild shampoo and a rinse off conditioner were formulated with the enzymatic hydrolysate and applied to hair fibers to evaluate the hydration, with and without heat, using a Corneometer® CM 825. The hydration was more efficient with heat, suggesting a more complete incorporation of hydrolysates into the fibers. Scanning Electron Microscopy showed deposits of organic matter in the junction of the cuticles that probably collaborates to the sealing of the cuticles, increasing the brightness and softness. Conclusions These results show that the enzymatic method to produce keratin peptides for hair care products is an attractive and eco- friendly method with a great potential in the cosmetic industry.

2013-01-01

299

Comparison of the aggregation behavior of soy and bovine whey protein hydrolysates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Soy-derived proteins (soy protein isolate, glycinin, and ß-conglycinin) and bovine whey-derived proteins (whey protein isolate, ¿-lactalbumin, ß-lactoglobulin) were hydrolyzed using subtilisin Carlsberg, chymotrypsin, trypsin, bromelain, and papain. The (in)solubility of the hydrolysates obtained was studied as a function of pH. At neutral pH, all soy-derived protein hydrolysates, particularly those from glycinin, obtained by hydrolysis with subtilisin Carlsberg, chymotrypsin, bro...

Kuipers, B. J. H.; Alting, A. C.; Gruppen, H.

2007-01-01

300

Impact of ultrafiltration and nanofiltration of an industrial fish protein hydrolysate on its bioactive properties  

Digital Repository Infrastructure Vision for European Research (DRIVER)

BACKGROUND: Numerous studies have demonstrated that in vitro controlled enzymatic hydrolysis of fish and shellfish proteins leads to bioactive peptides. Ultrafiltration (UF) and/or nanofiltration (NF) can be used to refine hydrolysates and also to fractionate them in order to obtain a peptide population enriched in selected sizes. This study was designed to highlight the impact of controlled UF and NF on the stability of biological activities of an industrial fish protein hydrolysate (FPH) an...

2010-01-01

 
 
 
 
301

Effect of Adsorption Medium, Hydrolytic Parameters and Ultrafiltration on the Phenylalanine Removal from Pancreatic Whey Hydrolysates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

With the aim of producing dietary supplements for phenylketonurics, using whey hydrolysates as protein sources, the effect of some procedures over phenylalanine (Phe) removal was evaluated. Twelve whey hydrolysates were prepared by the action of a pancreatin, in three enzyme:substrate (E:S) ratios and two temperatures. Half of the samples were submitted to the ultrafiltration (UF) through 10,000 Da cut-off membranes. The activated carbon and the polymeric adsorbent XAD-4 were used for removin...

2006-01-01

302

Effects of concentration on in vivo absorption of a peptide containing protein hydrolysate.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Amino acid absorption from a peptide-containing protein hydrolysate and an equivalent amino acid mixture over a range of concentrations of the two--such as is thought to be found in the normal intestine after a meal--has been studied using a jejunal perfusion technique in man. The relative rates of amino acid absorption from the protein hydrolysate and amino acid mixture varied markedly with concentration, demonstrating that the global hypothesis that peptides confer an advantage in amino aci...

Hegarty, J. E.; Fairclough, P. D.; Moriarty, K. J.; Kelly, M. J.; Clark, M. L.

1982-01-01

303

Production of Defatted Palm Kernel Cake Protein Hydrolysate as a Valuable Source of Natural Antioxidants  

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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 resul...

2012-01-01

304

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Liu, Liyuan; Wang, Yanping; Peng, Chen; Wang, Jinju

2013-01-01

305

Collagen metabolism of human osteoarthritic articular cartilage as modulated by bovine collagen hydrolysates  

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Destruction of articular cartilage is a characteristic feature of osteoarthritis (OA). Collagen hydrolysates are mixtures of collagen peptides and have gained huge public attention as nutriceuticals used for prophylaxis of OA. Here, we evaluated for the first time whether different bovine collagen hydrolysate preparations indeed modulate the metabolism of collagen and proteoglycans from human OA cartilage explants and determined the chemical composition of oligopeptides representing collagen ...

Schadow, Saskia; Siebert, Hans-christian; Lochnit, Gu?nter; Kordelle, Jens; Rickert, Markus; Steinmeyer, Ju?rgen

2013-01-01

306

Collagen Metabolism of Human Osteoarthritic Articular Cartilage as Modulated by Bovine Collagen Hydrolysates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Destruction of articular cartilage is a characteristic feature of osteoarthritis (OA). Collagen hydrolysates are mixtures of collagen peptides and have gained huge public attention as nutriceuticals used for prophylaxis of OA. Here, we evaluated for the first time whether different bovine collagen hydrolysate preparations indeed modulate the metabolism of collagen and proteoglycans from human OA cartilage explants and determined the chemical composition of oligopeptides representing collagen ...

Schadow, Saskia; Siebert, Hans-christian; Lochnit, Gu?nter; Kordelle, Jens; Rickert, Markus; Steinmeyer, Ju?rgen

2013-01-01

307

WPC Hydrolysates Obtained by the Action of a Pancreatin: Preparation, Analysis and Phenylalanine Removal  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this work was to use a pancreatin to obtain Whey Protein Concentrate (WPC) hydrolysates with high degree of hydrolysis, appropriate peptide profiles from the nutritional point of view as well as with reduced Phenylalanine (Phe) content. Six hydrolysates were prepared by varying the enzyme: Substrate ratio and the substrate concentration. The degree of hydrolysis was calculated by the ratio between a-amino and total nitrogen. The analysis of peptide profile involved the fractionatio...

Silvestre, Marialice P. C.; Silva, Maite C.; Silva, Viviane D. M.; Silva, Mauro R.; Amorin, Larissa L.

2011-01-01

308

Production of Lactic Acid by a Local Isolate of Lactobacillus plantarum Using Cheap Starchy Material Hydrolysates  

Directory of Open Access Journals (Sweden)

Full Text Available Some cheap starchy materials like sorghum grains and wheat bran were degraded by crude glucoamylase of a local isolate of Mucor sp., then Lactic Acid (LA was produced by a local isolate of L. plantarum using sorghum flour hydrolysate, sorghum starch hydrolysate, soluble starch hydrolysate, wheat bran hydrolysate and date syrup with 10% reducing sugars. The yield of LA increased to 37.2 g/100 reducing sugars by using sorghum flour hydrolysate as a basal medium supplemented with (0.6+0.6% yeast extract+(NH42HPO4 and 0.06% MgSO4.7H2O, reducing sugars was 5%. The fermentation temperature was 30°C/96 h. Results indicated that using hydrolysates mixtures of sorghum flour and wheat bran improved LA fermentation. The yield of LA was 92.5 g by using sorghum flour and 50% wheat bran. Paper chromatography indicated that LA was the unique organic acid in the fermented broth.

Amal Kadhim G. Al-Asady

2012-01-01

309

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

1997-01-01

310

Preparation, Characterization, and Microbial Degradation of Specifically Radiolabeled [14C]Lignocelluloses from Marine and Freshwater Macrophytes †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

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

1984-01-01

311

Utilization of anaerobically treated distillery spent wash for production of cellulases under solid-state fermentation.  

Science.gov (United States)

Pollution caused by distillery spent wash on one hand has stimulated the need to develop new technologies to treat the waste and on the other, forced us to reevaluate the efficient utilization of its nutritive potential for production of various high value compounds. In this study, anaerobically treated distillery spent wash was used for the production of cellulases by Aspergillus ellipticus under solid-state fermentation using wheat straw as a substrate. The interactions between distillery effluent concentration, initial pH, moisture content and inoculum size were investigated and modeled using response surface methodology (RSM) involving Box-Behnken design (BBD). Under optimized conditions, filter paper activity, beta-glucosidase and endo-beta-1,4-glucanase activities were found to be 13.38, 26.68 and 130.92 U/g of substrate respectively. Characterization of endo-beta-1,4-glucanase and beta-glucosidase was done after partial purification by ammonium sulfate fractionation followed by desalting. The partially purified endo-beta-1,4-glucanase and beta-glucosidase showed maximum activity at 60 degrees C. Saccharification studies performed with different lignocellulosic substrates showed that wheat bran was most susceptible to enzymatic hydrolysis. The study suggests that anaerobically treated distillery spent wash can be used as a viable nutrient source for cellulase production under solid-state fermentation by A. ellipticus. PMID:20627545

Acharya, Bhavik K; Mohana, Sarayu; Jog, Rahul; Divecha, Jyoti; Madamwar, Datta

2010-10-01

312

Effect of extrusion process on antioxidant and ACE inhibition properties from bovine haemoglobin concentrate hydrolysates incorporated into expanded maize products.  

Science.gov (United States)

Extrusion process has been widely used for the development of many functional foods. The aim of this study was to assess the effect of extrusion process on antioxidant and angiotensin-converting enzyme (ACE) inhibition properties from bovine haemoglobin concentrate (BHC) hydrolysates (P, FC, PF and FCF). Extrusion was carried out with a Brabender single screw extruder. The ACE inhibition and the antioxidant capacity (AC) were estimated by the inhibition of the ACE and ABTS+? radical cation expressed as Trolox equivalent antioxidant capacity (TEAC), respectively. The ACE inhibition and TEAC values from hydrolysates were significantly higher than that from BHC. The highest ACE inhibition corresponded to P hydrolysate and the highest TEAC corresponded to PF and FCF hydrolysates. The ACE inhibition and AC from extruded products with added hydrolysates were higher than that from maize control; however, the extrusion process modified both ACE inhibition and AC formerly present in hydrolysates. PMID:21568820

Cian, Raúl E; Luggren, Pablo; Drago, Silvina R

2011-11-01

313

Research reactor spent fuel status  

International Nuclear Information System (INIS)

In recent years the problems of spent fuel from research reactors have received increasing attention as concerns about ageing fuel storage facilities, their life extension and the ultimate disposal of spent fuel loom larger. The overall scope of these problems can be gauged by examination of the databases compiled and maintained by the IAEA. Data compiled in the research reactor spent fuel database are used to assess the status of research reactor spent fuel worldwide. Fuel assemblies, their types, enrichment, origin of enrichment and geological distribution among the industrialised and developing countries of the world are discussed. Some projections of spent fuel inventories to the year 2006 are presented and discussed. Fuel management practices in wet and dry storage facilities and the concerns of reactor operators about long-term storage of their spent fuel are presented and some of the activities carried out by the International Atomic Energy Agency to address the issues associated with research reactor spent fuel are outlined. It is clear that more exposure of the problems and concerns and more international co-operation will be necessary to resolve the outstanding issues. It is also clear that take-back programmes of foreign research reactor fuels, if and when they are implemented, will not continue indefinitely. At some stage in the not too distant future (in 2006 for foreign research reactors with US-origin fuel), research reactor operators will be faced with having to find their own solutions regarding the permanent disposal of their spent fuel. For countries with no nuclear power programme, the construction of geological repositories for the relatively small amounts of spent fuel from one or two research reactors is obviously not practicable. For such countries, access to a regional interim storage facility and eventually a regional or international repository for research reactor fuel would be an ideal solution. The time is ripe for serious discussion of regional or international solutions and to begin planning for the day when neither take-back programmes nor the reprocessing option might be available. (author)

2000-06-01

314

Fish meals, fish components, and fish protein hydrolysates as potential ingredients in pet foods.  

Science.gov (United States)

An experiment to determine the chemical composition and protein quality of 13 fish substrates (pollock by-products, n = 5; fish protein hydrolysates, n = 5; and fish meals, n = 3) was conducted. Two of these substrates, salmon protein hydrolysate (SPH) and salmon meal with crushed bones (SMB), were used to determine their palatability as components of dog diets. Pollock by-products differed in concentrations of CP, crude fat, and total AA by 71, 79, and 71%, respectively, and GE by 4.1 kcal/g. Fish protein hydrolysates and fish meals were less variable (approximately 18, 14, and 17%, and 1.4 kcal/g, respectively). Biogenic amine concentrations were much higher in fish protein hydrolysates as compared with pollock by-products and fish meals. Pollock liver and viscera had the highest total fatty acid concentrations; however, red salmon hydrolysate and SMB had the highest total PUFA concentrations (49.63 and 48.60 mg/g, respectively). Salmon protein hydrolysate had the highest protein solubility in 0.2% KOH. Based on calculations using immobilized digestive enzyme assay values, lysine digestibility of fish meal substrates was comparable to in vivo cecectomized rooster assay values and averaged approximately 90.3%. Also, pollock milt, pollock viscera, red salmon hydrolysate, and sole hydrolysate had comparable values as assessed by immobilized digestive enzyme assay and rooster assays. A chick protein efficiency ratio (PER) assay compared SMB and SPH to a whole egg meal control and showed that SMB had high protein quality (PER = 3.5), whereas SPH had poor protein quality (PER value less than 1.5). However, using whole egg meal as the reference protein, both fish substrates were found to be good protein sources with an essential AA index of 1.0 and 0.9 for SMB and SPH, respectively. In the dog palatability experiments, a chicken-based control diet and 2 diets containing 10% of either SPH or SMB were tested. Dogs consumed more of the SPH diet compared with the control, and similar amounts of the SMB and control diets. The intake ratios for each were 0.73 and 0.52, respectively. Salmon protein hydrolysate was especially palatable to dogs. These data suggest that chemical composition and nutritional quality of fish substrates differ greatly and are affected by the specific part of the fish used to prepare fish meals and fish protein hydrolysates. PMID:16971577

Folador, J F; Karr-Lilienthal, L K; Parsons, C M; Bauer, L L; Utterback, P L; Schasteen, C S; Bechtel, P J; Fahey, G C

2006-10-01

315

Overview of spent fuel management  

International Nuclear Information System (INIS)

The annual arising of spent fuel at nuclear power plants worldwide was about 10,000 t HM (tonnes heavy metal) in 1993. The projected cumulative amount of spent fuel generated by the year 2010 will reach 330,000 t HM. Considering that part of it will be reprocessed, the amount of spent fuel to be stored by the year 2010 would be about 215,000 t HM. Since the first large scale geological repositories for the final disposal of spent fuel are not expected to be in operation before the year 2010 (an even greater delay is foreseen) and reprocessing capacity will not be sufficiently expanded, the indications are that interim storage will be the primary option at least for the next 20 years. Continuous attention is being given by international organizations to the collection, analysis and exchange of information on spent fuel storage. Their role in this area is to provide a forum for exchanging information, to co-ordinate and encourage closer co-operation among Member States in certain research and development activities that are of common interest, and to assist countries in responding to problems and finding solutions. (author). 2 refs, 1 fig., 6 tabs

1995-08-01

316

Intermodal transfer of spent fuel  

International Nuclear Information System (INIS)

As a result of the international standardization of containerized cargo handling in ports around the world, maritime shipment handling is particularly uniform. Thus, handier exposure parameters will be relatively constant for ship-truck and ship-rail transfers at ports throughout the world. Inspectors' doses are expected to vary because of jurisdictional considerations. The results of this study should be applicable to truck-to-rail transfers. A study of the movement of spent fuel casks through ports, including the loading and unloading of containers from cargo vessels, afforded an opportunity to estimate the radiation doses to those individuals handling the spent fuels with doses to the public along subsequent transportation routes of the fuel. A number of states require redundant inspections and for escorts over long distances on highways; thus handlers, inspectors, escort personnel, and others who are not normally classified as radiation workers may sustain doses high enough to warrant concern about occupational safety. This paper addresses the question of radiation safety for these workers. Data were obtained during, observation of the offloading of reactor spent fuel (research reactor spent fuel, in this instance) which included estimates of exposure times and distances for handlers, inspectors and other workers during offloading and overnight storage. Exposure times and distance were also for other workers, including crane operators, scale operators, security personnel and truck drivers. RADTRAN calculational models and parameter values then facilitated estimation of the dose to workers during incident-free ship-to-truck transfer of spent fuel

1992-09-13

317

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

318

Effect of Peptide Size on Antioxidant Properties of African Yam Bean Seed (Sphenostylis stenocarpa) Protein Hydrolysate Fractions  

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Enzymatic hydrolysate of African yam bean seed protein isolate was prepared by treatment with alcalase. The hydrolysate was further fractionated into peptide sizes of <1, 1–3, 3–5 and 5–10 kDa using membrane ultrafiltration. The protein hydrolysate (APH) and its membrane ultrafiltration fractions were assayed for in vitro antioxidant activities. The <1 kDa peptides exhibited significantly better (p < 0.05) ferric reducing power, diphenyl-1-picryhydradzyl (DPPH) and hydroxyl radical scav...

2011-01-01

319

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

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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

320

Simultaneously improving xylose fermentation and tolerance to lignocellulosic inhibitors through evolutionary engineering of recombinant Saccharomyces cerevisiae harbouring xylose isomerase  

Science.gov (United States)

Background Yeasts tolerant to toxic inhibitors from steam-pretreated lignocellulose with xylose co-fermentation capability represent an appealing approach for 2nd generation ethanol production. Whereas rational engineering, mutagenesis and evolutionary engineering are established techniques for either improved xylose utilisation or enhancing yeast tolerance, this report focuses on the simultaneous enhancement of these attributes through mutagenesis and evolutionary engineering of Saccharomyces cerevisiae harbouring xylose isomerase in anoxic chemostat culture using non-detoxified pretreatment liquor from triticale straw. Results Following ethyl methanesulfonate (EMS) mutagenesis, Saccharomyces cerevisiae strain D5A+ (ATCC 200062 strain platform), harbouring the xylose isomerase (XI) gene for pentose co-fermentation was grown in anoxic chemostat culture for 100 generations at a dilution rate of 0.10 h-1 in a medium consisting of 60% (v/v) non-detoxified hydrolysate liquor from steam-pretreated triticale straw, supplemented with 20 g/L xylose as carbon source. In semi-aerobic batch cultures in the same medium, the isolated strain D5A+H exhibited a slightly lower maximum specific growth rate (?max?=?0.12?±?0.01 h-1) than strain TMB3400, with no ethanol production observed by the latter strain. Strain D5A+H also exhibited a shorter lag phase (4 h vs. 30 h) and complete removal of HMF, furfural and acetic acid from the fermentation broth within 24 h, reaching an ethanol concentration of 1.54 g/L at a yield (Yp/s) of 0.06 g/g xylose and a specific productivity of 2.08 g/gh. Evolutionary engineering profoundly affected the yeast metabolism, given that parental strain D5A+ exhibited an oxidative metabolism on xylose prior to strain development. Conclusions Physiological adaptations confirm improvements in the resistance to and conversion of inhibitors from pretreatment liquor with simultaneous enhancement of xylose to ethanol fermentation. These data support the sequential application of random mutagenesis followed by continuous culture under simultaneous selective pressure from inhibitors and xylose as primary carbon source.

2014-01-01

 
 
 
 
321

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

322

Evaluation of Candida acidothermophilum in ethanol production from lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

A Saccharomyces-cerevisiae-bases simultaneous saccharification and fermentation (SSF) of lignocellulosic biomass is limited to an operating temperature of about 37 C, and even a small increase in temperature can have a deleterious effect. This points to a need for a more thermotolerant yeast. To this end, S. cerevisiae D{sub 5}A and a thermotolerant yeast, Candida acidothermophilum, were tested at 37 C, 40 C, and 42 C using dilute-acid-pretreated poplar as substrate. At 40 C, C. acidothermophilum produced 80% of the theoretical ethanol yield, which was higher than the yield from S. cerevisiae D{sub 5}A at either 37 C or 40 C. At 42 C, C. acidothermophilum showed a slight drop in performance. On the basis of preliminary estimates, SSF with C. acidothermophilum at 40 C can recuce cellulase costs by about 16%. Proportionately greater savings can be realized at higher temperatures if such a high-temperature SSF is feasible. This demonstrates the advantage of using thermophilic or thermotolerant yeasts. (orig.)

Kadam, K.L.; Schmidt, S.L. [Biotechnology Center for Fuels and Chemicals, National Renewable Energy Lab., Golden, CO (United States)

1997-12-31

323

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

324

CONVERSION OF LIGNOCELLULOSIC MATERIAL TO CHEMICALS AND FUELS; TOPICAL  

International Nuclear Information System (INIS)

A direct conversion of cellulosic wastes, including resin-bonded furniture and building waste, to levulinate esters is being investigated with the view to producing fuels, solvents, and chemical intermediates as well as other useful by-products in an inexpensive process. The acid-catalyzed reaction of cellulosic materials with ethanol or methanol at 200 C gives good yields of levulinate and formate esters, as well as useful by-products, such as a solid residue (charcoal) and a resinous lignin residue. An initial plant design showed reasonable rates of return for production of purified ethyl levulinate and by-products. In this project, investigations have been performed to identify and develop reactions that utilize esters of levulinic acid produced during the acid-catalyzed ethanolysis reaction. We wish to develop uses for levulinate esters that allow their marketing at prices comparable to inexpensive polymer intermediates. These prices will allow a sufficient rate of return to justify building plants for utilizing the waste lignocellulosics. If need is demonstrated for purified levulinate, the initial plant design work may be adequate, at least until further pilot-scale work on the process is performed

2001-01-01

325

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.

2009-05-01

326

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

327

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

328

Spent fuel management in Spain  

International Nuclear Information System (INIS)

There are presently nine Light Water Reactors in operation, representing around a 34% of the overall electricity production. In the early years, a small amount of spent fuel was sent to be reprocessed, although this policy was cancelled in favor of the open cycle option. A state owned company, ENRESA, was created in 1984, which was given the mandate to manage all kinds of radioactive wastes generated in the country. Under the present scenario, a rough overall amount of 7000 tU of spent fuel will be produced during the lifetime of the plants, which will go into final disposal. (author)

1996-08-01

329

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

330

Defatted Jatropha curcas flour and protein isolate as materials for protein hydrolysates with biological activity.  

Science.gov (United States)

Jatropha curcas L. protein hydrolysates were produced by treatment of a non-toxic genotype with Alcalase as well as the digestive enzymes pepsin and pancreatin. The J. curcas protein hydrolysate produced with the pepsin-pancreatin system from protein isolate had the highest TEAC value and was shown to undergo single-electron transfer reactions in the ABTS(+) reduction assay, demonstrating its antioxidant capacity. Testing of antimicrobial activity in the J. curcas protein hydrolysates against seven bacterial pathogens showed no growth inhibitory effect in Gram-negative and Gram-positive bacteria. More ACE-I inhibitory active peptides were produced in the Alcalase hydrolysates obtained from J. curcas protein isolate. The protein hydrolysate obtained with Alcalase from defatted J. curcas flour as well as from the protein isolate showed the highest inhibitory effect of ADP-induced aggregation of human platelets in platelet-rich plasma. It is expected that the information collated will facilitate new applications of proteins present in Jatropha plant. PMID:23265458

Marrufo-Estrada, Duly M; Segura-Campos, Maira R; Chel-Guerrero, Luis A; Betancur-Ancona, David A

2013-05-01

331

Dietary Combination of Fish Oil and Hemoglobin Hydrolysates Alters Serum and Liver Lipid Contents in Rat  

Directory of Open Access Journals (Sweden)

Full Text Available Fish oil has been shown to have anti-inflammatory and anti-cancer effects, and to reduce serum triacylglycerol (TAG levels by stimulating lipid oxidation and inhibiting lipogenesis in the liver. A small number of studies have demonstrated the synergistic effect of fish oil and other bioactive components. This study examined the effect of fish oil in combination with porcine hemoglobin (Hb hydrolysates on serum and liver lipid contents in rats. Male Wistar rats were divided into four groups; one group was fed a casein and soybean oil-based semi-purified basal diet and other three groups were fed the basal diet supplemented with 2% fish oil, 0.175% Hb hydrolysates, and 2% fish oil plus 0.175% Hb hydrolysates, respectively, for 4 weeks. The fish oil diet decreased serum and liver TAG contents but did not change serum and liver cholesterol levels. The dietary combination of fish oil and Hb hydrolysates decreased serum and liver TAG and cholesterol contents owing to the additive effect of both compounds, and this diet reduced the serum non-high-density lipoprotein cholesterol content as a result of a synergistic effect. This hypolipidemic effect was in part caused by enhanced excretion of fecal fatty acids, neutral steroids, and acidic steroids. The results of this study suggest that the combined intake of fish oil and Hb hydrolysates may play beneficial roles in the prevention of cardiovascular disease as compared with fish oil alone.

Ryota Hosomi

2013-08-01

332

Aggregation properties of whey protein hydrolysates generated with Bacillus licheniformis proteinase activities.  

Science.gov (United States)

Hydrolysis of whey protein concentrate (WPC) with Alcalase 2.4 L, a Bacillus licheniformis proteinase preparation, induces gelation. The aggregation behavior of WPC hydrolysates generated with Alcalase and Prolyve 1000, a Bacillus licheniformis proteinase that did not induce gelation, were studied by turbidity and particle size analysis. With the use of synthetic peptide substrates, it was shown that Alcalase contains a glutamyl endopeptidase (GE) activity not present in Prolyve. Comparison of the aggregation behavior of WPC hydrolysates generated with Alcalase, Prolyve, and combinations of Prolyve with a GE activity isolated from Alcalase showed that GE was responsible for the observed enzyme-induced peptide aggregation in Alcalase hydrolysates. Hydrolysates generated with Prolyve, having a degree of hydrolysis (DH) of 11.8% and 10.4% of peptide material greater than 10 kDa, could be induced to aggregate by the addition of GE. These results emphasize the contribution of enzyme specificity to the physicochemical and functional characteristics of proteinase hydrolysates of WPC. PMID:15713050

Spellman, David; Kenny, Patricia; O'Cuinn, Gerard; FitzGerald, Richard J

2005-02-23

333

Spent fuel management in Canada  

International Nuclear Information System (INIS)

The current status of the Canadian Spent Fuel Management is described. This includes wet and dry interim storage, transportation issues and future plans regarding final disposal based on deep underground emplacement in stable granite rock. Extension of wet interim storage facilities is not planned, as dry storage technologies have found wide acceptance. (author)

1998-03-01

334

Reprocessing of spent nuclear fuel  

International Nuclear Information System (INIS)

This report covers: chemical-technology investigation of modified purex process for reprocessing of spent fuel; implementation of the procedure for obtaining plutonium peroxide and oxalate; research in the field of uranium, plutonium, and fission products separation by inorganic ion exchangers and extraction by organic solutions; study of the fission products in the heavy water RA reactor

1963-01-01

335

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 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

1984-01-01

336

Spent fuel characteristics & disposal considerations  

Energy Technology Data Exchange (ETDEWEB)

The fuel used in commercial nuclear power reactors is uranium, generally in the form of an oxide. The gas-cooled reactors developed in England use metallic uranium enclosed in a thin layer of Magnox. Since this fuel must be processed into a more stable form before disposal, we will not consider the characteristics of the Magnox spent fuel. The vast majority of the remaining power reactors in the world use uranium dioxide pellets in Zircaloy cladding as the fuel material. Reactors that are fueled with uranium dioxide generally use water as the moderator. If ordinary water is used, the reactors are called Light Water Reactors (LWR), while if water enriched in the deuterium isotope of hydrogen is used, the reactors are called Heavy Water reactors. The LWRs can be either pressurized reactors (PWR) or boiling water reactors (BWR). Both of these reactor types use uranium that has been enriched in the 235 isotope to about 3.5 to 4% total abundance. There may be minor differences in the details of the spent fuel characteristics for PWRs and BWRs, but for simplicity we will not consider these second-order effects. The Canadian designed reactor (CANDU) that is moderated by heavy water uses natural uranium without enrichment of the 235 isotope as the fuel. These reactors run at higher linear power density than LWRs and produce spent fuel with lower total burn-up than LWRs. Where these difference are important with respect to spent fuel management, we will discuss them. Otherwise, we will concentrate on spent fuel from LWRs.

Oversby, V.M.

1996-06-01

337

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

338

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

339

Spent fuel data for waste storage programs  

International Nuclear Information System (INIS)

Data on LWR spent fuel were compiled for dissemination to participants in DOE-sponsored waste storage programs. Included are mechanical descriptions of the existing major types of LWR fuel assemblies, spent LWR fuel fission product inventories and decay heat data, and inventories of LWR spent fuel currently in storage, with projections of future quantities

1980-01-01

340

Spent fuel integrity during dry storage.  

Science.gov (United States)

Information on spent fuel integrity is of interest in evaluating the impact of long-term dry storage on the behavior of spent fuel rods. Spent fuel used during cask performance tests at the Idaho National Engineering Laboratory (INEL) offers significant o...

M. A. McKinnon

1995-01-01

 
 
 
 
341

Spent Fuel Behavior in Various Storage Modes.  

Science.gov (United States)

Spent fuel integrity is a major consideration in licensing actions for spent fuel storage technologies. Wet storage is the main-line US spent fuel management technology. Dry storage and rod consolidation are moving toward fully-licensed status. This paper...

A. B. Johnson W. J. Bailey E. R. Gilbert

1986-01-01

342

High performance maleated lignocellulose epicarp fibers for copper ion removal  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english 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.

343

Systematic Investigation of Antioxidant Activity of Egg White Protein Hydrolysates Obtained by Pepsin  

Directory of Open Access Journals (Sweden)

Full Text Available Antioxidative activity of protein hydrolysates from egg white hydrolyzed by Pepsin with different Degrees of Hydrolysis (DHs was investigated. As the DH increased from 6.47 to 18.22%, the antioxidative activity of Egg White Protein Hydrolysates (EWPHs first increased and then decreased, except for the reducing power of EWPHs. The EWPHs with DH 16.93% showed higher DPPH radical scavenging activity (96.07±3.84%, hydroxyl radical scavenging activity (36.82±1.46%, superoxide anion scavenging activity (67.72±2.51% and inhibitory activity of tea oil autoxidation (62.68±2.32% compared to other EWPHs. At DH 18.22%, the EWPHs exhibited the strongest reducing power (0.34±0.014. The results revealed that antioxidative activity of protein hydrolysates from egg white was determined by the DH. According to the experimental results, the EWPHs have potential for use as a natural antioxidant for food preservation.

Shuguo Sun

2013-01-01

344

Study on the free radical scavenging activity of sea cucumber (Paracaudina chinens var.) gelatin hydrolysate  

Science.gov (United States)

Gelatin from the sea cucumber (Paracaudina chinens var.) was hydrolyzed by bromelain and the hydrolysate was found to have a high free radical scavenging activity. The hydrolysate was fractionated through an ultrafiltration membrane with 5 kDa molecular weight cutoff (MWCO). The portion (less than 5 kDa) was further separated by Sephadex G-25. The active peak was collected and assayed for free radical scavenging activity. The scavenging rates for superoxide anion radicals (O2·-) and hydroxyl radicals (·OH) of the fraction with the highest activity were 29.02% and 75.41%, respectively. A rabbit liver mitochondrial free radical damage model was adopted to study the free radical scavenging activity of the fraction. The results showed that the sea cucumber gelatin hydrolysate can prevent the damage of rabbit liver and mitochondria.

Zeng, Mingyong; Xiao, Feng; Zhao, Yuanhui; Liu, Zunying; Li, Bafang; Dong, Shiyuan

2007-07-01

345

Microbial production of 2,3 butanediol from seaweed hydrolysate using metabolically engineered Escherichia coli.  

Science.gov (United States)

A variety of biofuel and biorefinery products have been produced from engineered Escherichia coli till date. Most of these products had been derived from simple sugars in its pure form, rather than deriving it from alternative, renewable and carbon neutral sources, such as marine alga biomass. Engineering E. coli to use algal hydrolysate can make these an attractive carbon source for the industrial production of value added fuels and chemicals. This work reports the engineering of E. coli by a combination of gene deletion and synthetic pathway incorporation, for the efficient utilization of algal hydrolysate to produce BA (2,3 butanediol+acetoin) under microaerobic condition. Engineered strain produced ~19 g/L of total BA from algal hydrolysate in defined M9 salt media at a yield of 0.43 g/g. PMID:23567699

Mazumdar, Suman; Lee, Jinwon; Oh, Min-Kyu

2013-05-01

346

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

347

Fish protein hydrolysates: proximate composition, amino acid composition, antioxidant activities and applications: a review.  

Science.gov (United States)

The fish processing industry produces more than 60% by-products as waste, which includes skin, head, viscera, trimmings, liver, frames, bones, and roes. These by-product wastes contain good amount of protein rich material that are normally processed into low market-value products, such as animal feed, fish meal and fertilizer. In view of utilizing these fish industry wastes, and for increasing the value to several underutilised fish species, protein hydrolysates from fish proteins are being prepared by several researchers all over the world. Fish protein hydrolysates are breakdown products of enzymatic conversion of fish proteins into smaller peptides, which normally contain 2-20 amino acids. In recent years, fish protein hydrolysates have attracted much attention of food biotechnologists due to the availability of large quantities of raw material for the process, and presence of high protein content with good amino acid balance and bioactive peptides (antioxidant, antihypertensive, immunomodulatory and antimicrobial peptides). PMID:22980905

Chalamaiah, M; Dinesh Kumar, B; Hemalatha, R; Jyothirmayi, T

2012-12-15

348

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)

2008-01-01

349

Conversion of lignocellulosic waste by gamma irradiation and fungal fermentation  

International Nuclear Information System (INIS)

Effects of microbial elimination (initially contaminated bacteria and fungi) were confirmed at wide range of irradiation doses (15-30 kGy) with gamma rays of Co-60 for substrates with sawdusts, sugar cane baggasse, rice straw, oil palm fibre and others. Some changes of main components of basic polysaccharides and nitrogen sources in substrates under irradiation and fermentations have been examined to confirm effective conversions and assimilations of inorganic nitrogen into protein, particularly using N-15 tracer techniques. Biomass obtained by fungal fermentations would be used for animal feed and spent compots were useful for biofertilizer production. (author)

2000-01-01

350

Relationship between Calorific Value and Elementary Composition of Torrefied Lignocellulosic Biomass  

Directory of Open Access Journals (Sweden)

Full Text Available In this study, the relationship between calorific value and elementary composition of torrefied oil palm wastes (empty fruit bunches, mesocarp fiber and kernel shell and other lignocellulosic biomass is discussed. Several correlations for calorific value vs. elementary composition for biomass were examined for their applicability to torrefied lignocellulosic biomass. One of the correlations was selected as the most appropriate for the purpose, based on average absolute error between observed and estimated calorific values. In addition, the triangle plot of carbon, hydrogen and oxygen contents in untreated and pyrolyzed biomass is proposed as an appropriate tool for discussing biomass decomposition behavior.

S. Yusup

2010-01-01

351

Technoeconomic analysis of biofuels: A wiki-based platform for lignocellulosic biorefineries  

DEFF Research Database (Denmark)

We present a process model for a lignocellulosic ethanol biorefinery that is open to the biofuels academic community. Beyond providing a series of static results, the wiki-based platform provides a dynamic and transparent tool for analyzing, exploring, and communicating the impact of process advances and alternatives for biofuels production. The model is available for download (at http://econ.jbei.org) and will be updated based on feedback from the community of experts in biofuel-related fields. By making the assumptions and performance metrics of this model transparent, we anticipate this tool can provide a consensus on the energy-related, environmental, and economic performance of lignocellulosic ethanol.

Oleskowicz-Popiel, Piotr

2010-01-01

352

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

353

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 (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)

2001-04-01

354

Two-step process for conversion of lignocellulose into methane  

Energy Technology Data Exchange (ETDEWEB)

On-field burning of straw becoming prohibited throughout the EEC. Straw can represent a large potential source of energy for the production of biogas (methane) by anaerobic digestion but the lignocellolosic nature of the straw means that digestion is slow and yields may be poor. This study aims to examine the potential for a biological pretreatment using white-rot fungi to enhance the digestibility of barley straw, and to optimise the subsequent anaerobic digestion of partially delignified material. Among a wide range of white-rot fungi tested, PLEUROTUS OSTREATUS strains selectively delignify barly straw and produced a cellulose-rich straw. This cellulose-rich straw more than doubled the yield of reducing sugars during a cellulase digestion, and increased the methane yield by 22% more compared with untreated straw. However, when the dry matter lossed in the pretreatment are included in the estimations, there is no net increase in methane yield compared to untreated straw. As expected the methane yield increased with retention times when straw is digested in continously-fed digesters. Loading rates higher than 1.25 g straw/l digester/day resulted in a rapid drop in pH and inhibition of methanogenesis. Straw pretreated with PLEUROTUS OSTREATUS strains and digested in continously-fed reactors gave the similar results as batch-fed digestion. During anaerobic digestion hemicellulose was hydrolysed to the same extent over the range of retention times studied (10 to 47.5 days) whereas cellulose hydrolysis increased with increasing retention time. Chemical pretreatment of straw was found to be a more efficient method than biological pretreatment. Sodium hydroxide, mild acid and alkaline perioxide pretreatment increased the biogas yield between 15 and 160%. (AB).

Richards, S.R.; Spendler, F.H.

1989-07-15

355

Influence of the concentration of locust bean gum on the gelling ability of whey peptic hydrolysates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The gelling ability of whey proteins can be changed by limited hydrolysis and by the presence of other components such as polysaccharides; depending on the environmental conditions it can either be improved or impaired. In this work the effect of LBG on the heat-set gelation of aqueous whey protein hydrolysates (10 % w/w) from pepsin was assessed at pH 7.0 by small deformation rheology. Whey protein concentrate (WPC) and hydrolysates with a degree of hydrolysis (DH) of 1.5, ...

Rocha, Cristina; Hilliou, L.; Teixeira, J. A.; Gonc?alves, M. P.

2008-01-01

356

Oil Production from Yarrowia lipolytica Po1g Using Rice Bran Hydrolysate  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of this study was to produce microbial oil from Yarrowia lipolytica Po1g grown in defatted rice bran hydrolysate. After removing oil from rice bran by Soxhlet extraction, the bran is subjected to acid hydrolysis with various sulfuric acid concentrations (1–4% v/v), reaction times (1–8?h), and reaction temperatures (60–120°C). The optimal conditions for maximum total sugar production from the hydrolysate were found to be 3% sulfuric acid at 90°C for 6?h. Glucose was the...

Tsigie, Yeshitila Asteraye; Wang, Chun-yuan; Kasim, Novy S.; Diem, Quy-do; Huynh, Lien-huong; Ho, Quoc-phong; Truong, Chi-thanh; Ju, Yi-hsu

2012-01-01

357

In Vitro Antioxidant Activities of Protein Hydrolysate from Germinated Black Soybean (Glycine max L.  

Directory of Open Access Journals (Sweden)

Full Text Available During this study, the effect of germination in combination with in vitro pepsin and pancreatin digestion of protein flours extracted from black soybean on the production of bioactive peptides was investigated. Black soybean (Glycine max L. were germinated for 3 days (at 24, 48 and 72 h, respectively germination periods and harvested. Protein hydrolysates from germinated black soybean were prepared from protein isolate by in vitro digestion using pepsin and pancreatin and then evaluated for antioxidant activity. Soy protein hydrolysate from 48 h of germination exhibited the highest scavenging activity against 2, 2-Diphenyl-1-Picrylhydrazyl (DPPH free radicals (76.56 % at 2.5 mg/mL followed by 24 and 72 h (66.62 and 60.55% at 2.5 mg/mL, respectively. Protein hydrolysate from germinated black soybean also exhibited noticeable scavenging activity for hydroxyl. Soy protein hydrolysate from 48 h of germination (97.475% at 2 mg/mL significantly was the most effective in neutralizing •OH (p<0.05 than that from 24 and 72 h (88.56 and 92.5%, respectively at 2 mg/mL, compared to the nongerminated which was 34.42% also at the same concentration. In addition, soyprotein hydrolysate from 24 h of germination significantly showed the highest reducing power (0.32 at 2.0 mg/mL compared to that from 48 and 72 h germination period (0.25 and 0.23 at 2.0 mg/mL, respectively. Molecular Weights distribution of protein hydrolysates from germinated black soybean was believed to have correlation with their antioxidant activities. Results showed that germination with in vitro digestion (pepsin and pancreatin of protein hydrolysate from germinated black soybean was successful in production of natural antioxidant compounds which established obvious antioxidant potency than non-germinated. As conclusion, soy protein hydrolysate from 48 h of germination had the best antioxidant potency and could be used as natural antioxidant in food systems.

Ralison Solominoarisoa Sefatie

2013-04-01

358

Overview of spent fuel management and problems  

International Nuclear Information System (INIS)

Results compiled in the research reactor spent fuel database are used to assess the status of research reactor spent fuel worldwide. Fuel assemblies, their types, enrichment, origin of enrichment and geological distribution among the industrialized and developed countries of the world are discussed. Fuel management practices in wet and dry storage facilities and the concerns of reactor operators about long-term storage of their spent fuel are presented and some of the activities carried out by the International Atomic Energy Agency to address the issues associated with research reactor spent fuel are outlined. Some projections of spent fuel inventories to the year 2006 are presented and discussed. (author)

1998-03-29

359

Spent graphite sleeve treatment facility  

International Nuclear Information System (INIS)

Fuji Electric Co., Ltd. has provided a spent graphite sleeve treatment facility to TOKAI nuclear power station of Japan Atomic Power Co., Inc (JAPC) The facility is a solid radwaste processing plant which is composed of volume reduction, heat sealing, removing and storage systems. TOKAI station has been storaged spent graphite sleeves in the bunker in the reactor building, but the bunker volume is not sufficient for long term operation. Therefore the new processing and storage facility has been introduced. Its feature is to fill up sleeves in a vinyl chloride container and seal this with remote operation. Fuji Electric has provided overall mechanical and electrical systems and plant engineering. The plant has achieved an excellent availability and already processed 400 fuel channels; 3,200 graphite sleeves. (author)

1988-01-01

360

Actinide removal from spent salts  

Energy Technology Data Exchange (ETDEWEB)

A method for removing actinide contaminants (uranium and thorium) 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 are added to precipitate the thorium as thorium oxide and/or the uranium as either uranium oxide or as a diuranate salt. The precipitated materials are filtered, dried and packaged for disposal as radioactive waste. About 90% of the thorium and/or uranium present is removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 0.1 ppm of thorium or uranium.

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

2002-01-01

 
 
 
 
361

Spent catalyst processing with electrochemistry  

Energy Technology Data Exchange (ETDEWEB)

Increasing concern for pollution prevention and waste disposal has created a need for clean alternatives for spent catalyst processing. In addition, expanded use of catalysts for the production of fuels and chemical feedstocks will continue in response to (1) economic pressure to upgrade heavier crudes and other feeds having high levels of impurities; (2) competitive pressure to achieve higher conversions using less energy; and (3) pressure to increase reaction selectivities to minimize waste production. While the incentives for using catalysts are great, all catalysts gradually lose activity through coking; poisoning by metals, sulfur, or halides; or loss of surface area from sintering at high process temperatures. Regeneration is possible where the catalyst deactivation can easily be reversed. Electrochemical dissolution is a new technique to oxidize catalyst contaminants and dissolve catalyst metals in an aqueous solution for further recovery of the raw materials. The key to this process is adding spent catalyst to a solution containing small amounts of species that form kinetically active, strongly oxidizing ions such as cerium(IV) or silver(II). The oxidizing ions are regenerated at the anode; they act in a catalytic manner carrying electrons from the solid surface to the anode of the electrochemical cell. A cerium oxidizer was used for the experiments described in this paper. For this procedure, solution is added to the anode side of an electrochemical cell. At the anode, aqueous cerium(III) is oxidized to cerium(IV). The cerium(IV), in turn, oxidizes organic material adhered to the catalyst to carbon dioxide and water. Many spent catalysts used in hydrogenations contain metal sulfides that have contaminated the catalyst surface during processing. Metal sulfides are oxidized to dissolved metal ions and sulfur species. Because cerium is continuously reoxidized to cerium(IV) at the anode, a small amount of cerium is needed to oxidize the spent catalyst.

Silva, L.J.; Bray, L.A.; Frye, J.G.; Buehler, M.F.

1994-11-01

362

Spent fuel integrity during transportation  

Energy Technology Data Exchange (ETDEWEB)

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.

Funk, C.W.; Jacobson, L.D.

1980-01-01

363

TMI-2 spent fuel shipping  

Energy Technology Data Exchange (ETDEWEB)

TMI-2 failed fuel will be shipped to the Idaho National Engineering Laboratory for use in the DOE Core Examination Program. The fuel debris will be loaded into three types of canisters during defueling and dry loaded into a spent fuel shipping cask. The cask design accommodates seven canisters per cask and has two separate containment vessels with ''leaktight'' seals. Shipments are expectd to begin in early 1986.

Quinn, G.J.; Burton, H.M.

1985-01-01

364

Spent fuel: Nuclear security issues  

International Nuclear Information System (INIS)

The paper gives an overview of the current global security threats facing the nuclear industry, with particular reference to spent fuel. It describes the types of nuclear facilities and activities involving radioactive materials that are at risk and the international measures established to counter the risks. In particular, it describes the activities of the International Atomic Energy Agency aimed at assisting its Member States in the nuclear security area. (author)

2007-07-01

365

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

2004-12-27

366

Spent fuel transport and reprocessing  

International Nuclear Information System (INIS)

The reprocessing experience in India started with the commissioning in 1964 at Trombay a plant designed to handle metallic uranium fuels from research reactors. This was entirely executed by indigenous effort. Since then the reprocessing programme has evolved in stages matching with the growth of nuclear programme. The reprocessing plant at Tarapur, under operation at present, is the next one to be built capable of reprocessing uranium oxide fuels from the power reactors at Rajasthan (PHWR) and Tarapur (BWR). The third plant now under construction will reprocess the spent fuels from the power reactors (PHWR) and the Fast Breeder Test Reactor (FBTR) located at Kalpakkam. By this planned progressive approach considerable experience has been acquired which will be useful in the design and construction of even larger plants to meet the projected demands. Setting up of a larger plant is being planned. To meet the increasing demands for movement of spent fuel arisings from reactors to reprocessing plants, transportation casks, each weighing up to 70 tonnes, have been designed and manufactured within the country. These casks each conform to test standards stipulated in the IAEA transport regulations. This paper discusses the experience in aspects dealing with spent fuel transport and reprocessing

1985-05-19

367

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

1993-01-01

368

Experimental methods for laboratory-scale ensilage of lignocellulosic biomass  

International Nuclear Information System (INIS)

Anaerobic fermentation is a potential storage method for lignocellulosic biomass in biofuel production processes. Since biomass is seasonally harvested, stocks are often dried or frozen at laboratory scale prior to fermentation experiments. Such treatments prior to fermentation studies cause irreversible changes in the plant cells, influencing the initial state of biomass and thereby the progression of the fermentation processes itself. This study investigated the effects of drying, refrigeration, and freezing relative to freshly harvested corn stover in lab-scale ensilage studies. Particle sizes, as well as post-ensilage drying temperatures for compositional analysis, were tested to identify the appropriate sample processing methods. After 21 days of ensilage the lowest pH value (3.73 ± 0.03), lowest dry matter loss (4.28 ± 0.26 g. 100 g-1DM), and highest water soluble carbohydrate (WSC) concentrations (7.73 ± 0.26 g. 100 g-1DM) were observed in control biomass (stover ensiled within 12 h of harvest without any treatments). WSC concentration was significantly reduced in samples refrigerated for 7 days prior to ensilage (3.86 ± 0.49 g. 100 g?1 DM). However, biomass frozen prior to ensilage produced statistically similar results to the fresh biomass control, especially in treatments with cell wall degrading enzymes. Grinding to decrease particle size reduced the variance amongst replicates for pH values of individual reactors to a minor extent. Drying biomass prior to extraction of WSCs resulted in degradation of the carbohydrates and a reduced estimate of their concentrations. The methods developed in this study can be used to improve ensilage experiments and thereby help in developing ensilage as a storage method for biofuel production. -- Highlights: ? Laboratory-scale methods to assess the influence of ensilage biofuel production. ? Drying, freezing, and refrigeration of biomass influenced microbial fermentation. ? Freshly ensiled stover exhibited the most preferable characteristics. ? Frozen biomass was statistically similar to freshly ensiled stover. ? Modified phenol-sulfuric method provides appropriate results and better resolution.

2012-12-01

369

Electropolar effects on anaerobic fermentation of lignocellulosic materials in novel single-electrode cells.  

Science.gov (United States)

As a promising renewable energy technology, anaerobic fermentation is consistently limited by low production and calorific value of biogas, along with the difficulty of lignocellulose degradation. The effects of polarity and micro-voltage on anaerobic fermentation from lignocellulosic materials were investigated in single-electrode fermenter to explore cost-efficient technology. The results illustrated that the biogas production and quality were significantly affected by electric polarity. And cathode-assisted fermentation led to more positive effects than anode-assisted. Compared with results in control group without electrode, the average biogas and methane yield under cathodic micro-voltage (-250mV) were astonishingly improved by 2.82 and 2.44mLg(-1)d(-1) respectively. Meanwhile, the degradation ratios of lignin and cellulose were also improved by 23.11% and 19.46%. It demonstrated that single micro-voltage can not only promote lignocellulose degradation but biogas production and calorific value. These micro-voltage effects on fermentation process also provided great opportunity to breakthrough the present limitation of lignocellulosic materials fermentation. PMID:24632630

Qu, Guangfei; Qiu, Weixia; Liu, Yuhuan; Zhong, Dongwei; Ning, Ping

2014-05-01

370

Draft Genome Sequence of the Lignocellulose Decomposer Thermobifida fusca Strain TM51  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Here, we present the complete genome sequence of Thermobifida fusca strain TM51, which was isolated from the hot upper layer of a compost pile in Hungary. T. fusca TM51 is a thermotolerant, aerobic actinomycete with outstanding lignocellulose-decomposing activity.

To?th, A?kos; Barna, Tere?zia; Horva?th, Bala?zs; Nagy, Istva?n; Ta?ncsics, Andra?s; Kriszt, Bala?zs; Baka, Erzse?bet; Fekete, Csaba; Kukolya, Jo?zsef

2013-01-01

371

Draft Genome Sequence of the Lignocellulose Decomposer Thermobifida fusca Strain TM51.  

Science.gov (United States)

Here, we present the complete genome sequence of Thermobifida fusca strain TM51, which was isolated from the hot upper layer of a compost pile in Hungary. T. fusca TM51 is a thermotolerant, aerobic actinomycete with outstanding lignocellulose-decomposing activity. PMID:23846276

Tóth, Akos; Barna, Terézia; Nagy, István; Horváth, Balázs; Nagy, István; Táncsics, András; Kriszt, Balázs; Baka, Erzsébet; Fekete, Csaba; Kukolya, József

2013-01-01

372

Characterization of ligno-cellulosic materials bleached with oxo-diperoxo-molybdates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A newly effective system was used to bleach ligno-cellulosic textile materials. This system is based on two different newly synthesized natrium oxo-diperoxo molybdates, Na2[MoO (O2)2(C2O4)] and Na2[MoO (O2)2(C6H6O7)].

Si?rghiea, Cecilia; Bodescu, Adina-maria; Botar, Alexandru; Paulo, Artur Cavaco; Munteanu, Florentina-daniela

2013-01-01

373

The Chemistry and Technology of Furfural Production in Modern Lignocellulose-Feedstock Biorefineries:  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This dissertation deals with biorefinery technology development, i.e. with the development of sustainable industrial methods aimed at the production of chemicals, fuels, heat and power from lignocellulosic biomass. This work is particularly focused on the production of furfural from hemicellulose-derived pentoses.

2011-01-01

374

Rate of formation/decomposition and methane fermentability of autohydrolysis products from lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

The fermentation of lignocellulose to methane, a potential renewable energy resource, is limited by lignocellulose's lignin content and the crystallinity of cellulose. Autohydrolysis, aqueous heat treatment under pressure at temperatures from 175 to 250/sup 0/C without chemical addition, is a potential pretreatment for increasing the fermentability of lignocellulose. Factors affecting the rates of product formation and decomposition during staged autohydrolysis were determined in order to find conditions that enhance the production of fermentable products. Staged autohydrolysis and biodegradability/toxicity pretreatments were performed in bomb-type autoclaves, while kinetic studies were conducted in a constant temperature bath. Staged autohydrolysis of white fir increased the production of biodegradable products. The first stage at mild conditions solubilized hemicellulose, and subsequent stages at more severe conditions solubilized the cellulose, but carbohydrate decomposition also occurred. The kinetics of monosaccharide decomposition and product formation were evlauated as a function of temperature and pH. The rate of monosaccharide decomposition was subject to general acid-base catalysis with temperature modeled by the Arrhenius relationship. A model was developed which accounts for the major products from staged autohydrolysis of lignocellulose. Application of the model indicated that the formation of biodegradable products is optimized when the pH is less than 3.

Baugh, K.D.

1983-01-01

375

Real-time understanding of lignocellulosic bioethanol fermentation by Raman spectroscopy  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Abstract Background A substantial barrier to commercialization of lignocellulosic ethanol production is a lack of process specific sensors and associated control strategies that are essential for economic viability. Current sensors and analytical techniques require lengthy offline analysis or are easily fouled in situ. Raman spectroscopy has the potential to continuously monitor fermentation reactants and products, maximizing efficiency and allowing for improved process contr...

Ewanick Shannon M; Thompson Wesley J; Marquardt Brian J; Bura Renata

2013-01-01

376

Analysis of taste-active compounds in an enzymatic hydrolysate of deamidated wheat gluten.  

Science.gov (United States)

Hydrolyzed plant proteins are widely used as ingredients in culinary products for their glutamate-like ("umami") taste. Three hydrolysates were prepared from wheat gluten using different enzymatic approaches. Comparison of their taste profiles revealed the enzymatic hydrolysate of an acid-deamidated wheat gluten (WGH-3) to be the least bitter of all and to elicit an intense glutamate-like taste. Its umami taste intensity was similar to that of an enzymatic hydrolysate in which glutaminase had been employed to convert free glutamine to glutamic acid and which had a 3-fold higher concentration of free glutamate. Reconstitution studies based on the results of the chemical analysis of WGH-3 and sensory comparison of the model solution and WGH-3 indicated that other components in addition to glutamate and organic acids contribute to its glutamate-like taste. WGH-3 was fractionated by gel permeation chromatography and reversed phase high-performance liquid chromatography, and two fractions with a pronounced glutamate-like taste were obtained. In one of them four pyroglutamyl peptides were tentatively identified: pGlu-Pro-Ser, pGlu-Pro, pGlu-Pro-Glu, and pGlu-Pro-Gln. Apparently, these peptides were formed by cyclization of the N-terminal glutamine residues during the preparation of the hydrolysates. PMID:11879030

Schlichtherle-Cerny, Hedwig; Amadò, Renato

2002-03-13

377

Genetic Engineering of Enterobacter asburiae Strain JDR-1 for Efficient Production of Ethanol from Hemicellulose Hydrolysates?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Dilute acid pretreatment is an established method for hydrolyzing the methylglucuronoxylans of hemicellulose to release fermentable xylose. In addition to xylose, this process releases the aldouronate methylglucuronoxylose, which cannot be metabolized by current ethanologenic biocatalysts. Enterobacter asburiae JDR-1, isolated from colonized wood, was found to efficiently ferment both methylglucuronoxylose and xylose in acid hydrolysates of sweet gum xylan, producing predominantly ethanol and...

Bi, Changhao; Zhang, Xueli; Ingram, Lonnie O.; Preston, James F.

2009-01-01

378

Effect of Adsorption Medium, Hydrolytic Parameters and Ultrafiltration on the Phenylalanine Removal from Pancreatic Whey Hydrolysates  

Directory of Open Access Journals (Sweden)

Full Text Available With the aim of producing dietary supplements for phenylketonurics, using whey hydrolysates as protein sources, the effect of some procedures over phenylalanine (Phe removal was evaluated. Twelve whey hydrolysates were prepared by the action of a pancreatin, in three enzyme:substrate (E:S ratios and two temperatures. Half of the samples were submitted to the ultrafiltration (UF through 10,000 Da cut-off membranes. The activated carbon and the polymeric adsorbent XAD-4 were used for removing Phe from the hydrolysates. The results showed that the activated carbon was more advantageous than the resin, since it led to the lowest final Phe content (2.3 to 38.2 mg Phe/100 g hydrolysate. The effect of E:S ratio, temperature and ultrafiltration was also evaluated. The least final amount of Phe was obtained in absence of UF for three situations: E:S = 0.01% and 25°C, E:S = 0.1% and 50°C, E:S = 1.0% and 50°C.

Fernanda M. Delvivo

2006-01-01

379

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.

380

WPC Hydrolysates Obtained by the Action of a Pancreatin: Preparation, Analysis and Phenylalanine Removal  

Directory of Open Access Journals (Sweden)

Full Text Available The aim of this work was to use a pancreatin to obtain Whey Protein Concentrate (WPC hydrolysates with high degree of hydrolysis, appropriate peptide profiles from the nutritional point of view as well as with reduced Phenylalanine (Phe content. Six hydrolysates were prepared by varying the enzyme: Substrate ratio and the substrate concentration. The degree of hydrolysis was calculated by the ratio between a-amino and total nitrogen. The analysis of peptide profile involved the fractionation of hydrolysates by high performance size-exclusion liquid chromatography and the rapid correct fraction area method was used to quantify the chromatographic fraction components. The activated carbon was used to remove Phe and the efficiency of this procedure was evaluated by measuring the amount of this amino acid by second derivative spectrophotometry. The results showed that the degree of hydrolysis changed from 15 to 30%. An appropriate peptide profile was obtained with high free amino acid (55.43% and low large peptide (15.75% contents as well as an amount of di and tripeptides greater than 6%. Also, Phe removal changed from 59.1 to 81.3%. The economical advantage of using the smallest enzyme: Substrate ratio (1:100 was associated to the achievement of the best peptide profile. Thus, the use of a pancreatin in the hydrolytic conditions tested in the current study produced WPC hydrolysates with high degree of hydrolysis, suitable peptide profile and reduced Phe content.

Larissa L. Amorin

2011-01-01

 
 
 
 
381

Antioxidant activity and oxidative stress protection of duck proteins hydrolysates in SK-N-SH cells.  

Science.gov (United States)

Studies have found that natural antioxidants, which are free-radical scavengers, can reduce the risk of diseases caused by free radicals. This work investigated the antioxidant properties of duck proteins hydrolysates. The free-radical scavenging function of CP-1 (M(r) > 10 kDa), CP-2 (5 kDa SK-N-SH cells. PMID:23295546

Guo, Yuxing; Pan, Daodong; Wu, Zhen; Zhao, Chuanchuan; Cao, Jinxuan

2013-02-26

382

Evaluation of Phenolic Content and Antioxidant Property of Hydrolysed Extracts of Terminalia catappa L. Leaf  

Directory of Open Access Journals (Sweden)

Full Text Available The influence of acid and alkaline hydrolysis on the phenolic content and antioxidant activity of Terminalia catappa L. leaves were evaluated in this study. Polyphenolic content was determined using total phenolic, total flavonoid and total tannin assays. Four in vitro antioxidant assays such as DPPH, ABTS, Ferric Reducing Antioxidant Potency (FRAP and total antioxidant capacity assays were followed to determine the antioxidant potency of the extracts and the values were expressed as mg vitamin C equivalent antioxidant capacity (VCEAC/g extract. The results of this study indicated that acid hydrolysed and alkaline hydrolysed extracts possess fewer amounts of polyphenolic constituents in comparison with non hydrolysed extract. Even the VCEAC values of non hydrolysed extract in antioxidant assays were significantly higher (pin vitro results. A strong correlation was observed for polyphenolic content and antioxidant activities of these extracts ensuring the involvement of polyphenolic content for the antioxidant activity. However, the results of this study may not be generalised for all plants as different plants possess different phytoconstituents in varying quantities.

S. Ramanathan

2010-01-01

383

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; Viitanen, Paul V; Stieglitz, Barry

2013-10-29

384

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

385

Adsorptive Membranes vs. Resins for Acetic Acid Removal from Biomass Hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

Acetic acid is a compound commonly found in hemicellulosic hydrolysates. This weak acid strongly influences the bioconversion of sugar containing hydrolysates. Previous investigators have used anion exchange resins for acetic acid removal from different hemicellulosic hydrolysates. In this study, the efficiency of an anion exchange membrane was compared to that of an anion exchange resin, for acetic acid removal from a DI water solution and an acidic hemicellulose hydrolysate pretreated using two different methods. Ion exchange membranes and resins have very different geometries. Here the performance of membranes and resins is compared using two dimensionless parameters, the relative mass throughput and chromatographic bed number. The relative mass throughput arises naturally from the Thomas solution for ion exchange. The results show that the membrane exhibit better performance in terms of capacity, and loss of the desired sugars. In addition acetic acid may be eluted at a higher concentration from the membrane thus leading to the possibility of recovery and re-use of the acetic acid.

Han, B.; Carvalho, W.; Canilha, L.; da Silva, S. S.; e Silva, J. B. A.; McMillan, J. D.; Wickramasinghe, S. R.

2006-01-01

386

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

1998-01-01

387

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

1998-01-01

388

Kinetic considerations about the study of alcoholic fermentations in starch hydrolysate  

Energy Technology Data Exchange (ETDEWEB)

Alcoholic fermentations of starch hydrolysate by two different yeast strains, Saccharomyces cerevisiae (var. Vinal) and Saccharomyces oviformis (IMAP 383), have been studied in batch runs. In order to evaluate the different inhibition phenomena due to both substrate and product, a new kinetic equation is suggested. 23 references.

Converti, A.; Perego, P.; Del Borghi, M.; Parisi, F.; Ferraiolo, G.

1986-05-01

389

CASTOR gets spent fuel to Sellafield [spent fuel caskets  

International Nuclear Information System (INIS)

The first transport of spent fuel from Germany to the UK using the GNS CASTOR flask is expected to take place this month. Two flasks manufactured from highly ductile cast iron have been developed for wet transport between nuclear power stations and the reprocessing plant at Sellafield. They are basically similar in design and differ only in length. CASTOR S1 is designed for the transport of five or six PWR fuel assemblies (long type). CASTOR S2 is designed for the transport of 14 or 17 BWR fuel assemblies or seven PWR fuel assemblies (short type). They are briefly described. (author)

1989-01-01

390

Impact of nitrogen and phosphorus on [14C]lignocellulose decomposition by stream wood microflora  

International Nuclear Information System (INIS)

Nutritional and physical factors affecting the decomposition of [14C]lignocellulose prepared for Douglas fir (Pseudotsuga menziesii) were examined by incubating the labeled substrate with homogenized surface wood scrapings obtained from a Douglas fir log in a Pacific Northwest stream. Decomposition rates of [14C]lignocellulose, as measured by 14CO2 evolution, were greater in each of the four filter-sterilized sources of stream water than in distilled water alone. Decomposition experiments conducted in stream water media with the addition of defined mineral salts demonstrated that [14C]cellulose decomposition was stimulated 50% by the addition of either KNO3 or KH2/PO4K2HPO4 and further enhanced (167%) by a combination of both. In contrast, [14C]lignin decomposition was stimulated (65%) only by the addition of both N and P. Decomposition of [14C]lignocellulose was greatest when supplemental KNO3 was supplied in concentrations of at least 10.0 mg of N liter-1 but not increased further by higher concentrations. The decomposition of [14C]lignocellulose increased as the incubation temperature was raised and NO3--N supplementation further increased these rates between three- and sevenfold over the range of temperatures examined (5 to 220C). Accumulation of NH4+ (2 to 4 mg of N liter-1) was always observed in culture filtrates of incubations which had been supplemented with KNO3, the quantity being independent of NO3- concentrations greater than or equal to 10 mg of N liter-1. The role of supplemental NO3- in the decomposition of [14C]lignocellulose is discussed in relation to wood decomposition and the low concentrations of N found in stream ecosystems of the Pacific Northwest

1985-01-01

391

Lima Bean (Phaseolus lunatus Protein Hydrolysates with ACE-I Inhibitory Activity  

Directory of Open Access Journals (Sweden)

Full Text Available Several protein sources can be used to produce bioactive peptides with angiotensin I-converting enzyme (ACE inhibittory activity. Protein concentrates from ungerminated and germinated lima bean Phaseolus lunatus seed flours were hydrolyzed with Alcalase 2.4 L or pepsin-pancreatin sequential hydrolysis, and ACE inhibitory activity measured in the different hydrolysis treatments. Protein hydrolysate production was analyzed with a 23 factorial design with four replicates of the central treatment. Evaluated factors were protein concentrate source (ungerminated seeds, PC1; germinated seeds, PC2, enzyme/substrate ratio E/S (1/50 or 1/10 and hydrolysis time (0.5 or 2.0 h for Alcalase; 1 or 3 h for pepsin-pancreatin. Degree of hydrolysis (DH was high for the Alcalase hydrolysates (24.12% 58.94%, but the pepsin-pancreatin hydrolysates exhibited the highest ACE inhibitory activity (IC50 = 0.250 0.692 mg/mL. Under the tested conditions, the hydrolysates with the highest ACE inhibitory activity were produced with sequential pepsin-pancreatin using either PC1 at 1 h hydrolysis time and a 1/10 E/S ratio or PC2 at 1 h hydrolysis time and a 1/50 E/S ratio. Lima bean protein hydrolysates prepared with Alcalase or pepsin-pancreatin are a potential ingredient in the production of physiologically functional foods with antihypertensive activity.

David Betancur-Ancona

2012-04-01

392

What does time spent on searching indicate?  

DEFF Research Database (Denmark)

In this paper, we report a comparative study on what usersâ?? time spent on searching for information is an indication of. Time spent is commonly interpreted as an implicit measure of interest, but might indeed describe other circumstances of the information retrieval (IR) interaction. This phenomenon of time spent is interesting from an IR evaluation point of view with reference to how time spent is to be interpreted. A comparison of time spent between a semi-lab interactive IR (IIR) study using simulated work task situations and a naturalistic IIR study is presented. The findings of this comparison are further related to a study on information searching and seeking in the real work environment that provides a resonance board for the reported IIR studies. The main conclusion is that time spent searching depends not only on interest, but also on circumstances such as prior knowledge and external requirements.

Borlund, Pia; Dreier, Sabine

2012-01-01

393

Spent nuclear fuel shipping basket  

Energy Technology Data Exchange (ETDEWEB)

A spent nuclear fuel shipping basket is described. A shell has a lower wall section of greater thickness than the remainder of the shell and a plurality of notches spaced apart around its inner circumference and extending the length of said shell. A plurality of drain holes are provided in the lower end plate of the shell. A plurality of cruciforms are sized to receive fuel cans. The cruciforms are formed from a neutron absorber and heat transfer material. Ring supports are spaced apart along the length of the shell and receive and transfer operating loads from the fuel cans to the shell and the shipping cask that receives the basket. 3 figures.

DeCooman, W.J. Sr.; Lafleur, J.F.

1994-12-13

394

Spent fuel canister docking station  

Energy Technology Data Exchange (ETDEWEB)

The working report for the spent fuel canister docking station presents a design for the operation and structure of the docking equipment located in the fuel handling cell for the spent fuel in the encapsulation plant. The report contains a description of the basic requirements for the docking station equipment and their implementation, the operation of the equipment, maintenance and a cost estimate. In the designing of the equipment all the problems related with the operation have been solved at the level of principle, nevertheless, detailed designing and the selection of final components have not yet been carried out. In case of defects and failures, solutions have been considered for postulated problems, and furthermore, the entire equipment was gone through by the means of systematic risk analysis (PFMEA). During the docking station designing we came across with needs to influence the structure of the actual disposal canister for spent nuclear fuel, too. Proposed changes for the structure of the steel lid fastening screw were included in the report. The report also contains a description of installation with the fuel handling cell structures. The purpose of the docking station for the fuel handling cell is to position and to seal the disposal canister for spent nuclear fuel into a penetration located on the cell floor and to provide suitable means for executing the loading of the disposal canister and the changing of atmosphere. The designed docking station consists of a docking ring, a covering hatch, a protective cone and an atmosphere-changing cap as well as the vacuum technology pertaining to the changing of atmosphere and the inert gas system. As far as the solutions are concerned, we have arrived at rather simple structures and most of the actuators of the system are situated outside of the actual fuel handling cell. When necessary, the equipment can also be used for the dismantling of a faulty disposal canister, cut from its upper end by machining. The overall cost estimate for the manufacture of the equipment, value added tax not included, totalled 669 000 EUR, of which 189 000 EUR constituted designing costs and 73 000 EUR installation costs. (orig.)

Suikki, M. [Afore Oy, Turku (Finland)

2006-01-15

395

HTGR spent fuel storage study  

International Nuclear Information System (INIS)

This report documents a study of alternate methods of storing high-temperature gas-cooled reactor (HTGR) spent fuel. General requirements and design considerations are defined for a storage facility integral to a fuel recycle plant. Requirements for stand-alone storage are briefly considered. Three alternate water-cooled storage conceptual designs (plug well, portable well, and monolith) are considered and compared to a previous air-cooled design. A concept using portable storage wells in racks appears to be the most favorable, subject to seismic analysis and economic evaluation verification

1979-01-01