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1

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

2

Hydrolysates of lignocellulosic materials for biohydrogen production.  

UK PubMed Central (United Kingdom)

Lignocellulosic materials are commonly used in bio-H2 production for the sustainable energy resource development as they are abundant, cheap, renewable and highly biodegradable. In the process of the bio-H2 production, the pretreated lignocellulosic materials are firstly converted to monosaccharides by enzymolysis and then to H2 by fermentation. Since the structures of lignocellulosic materials are rather complex, the hydrolysates vary with the used materials. Even using the same lignocellulosic materials, the hydrolysates also change with different pretreatment methods. It has been shown that the appropriate hydrolysate compositions can dramatically improve the biological activities and bio-H2 production performances. Over the past decades, hydrolysis with respect to different lignocellulosic materials and pretreatments has been widely investigated. Besides, effects of the hydrolysates on the biohydrogen yields have also been examined. In this review, recent studies on hydrolysis as well as their effects on the biohydrogen production performance are summarized.

Chen R; Wang YZ; Liao Q; Zhu X; Xu TF

2013-05-01

3

Hydrolysates of lignocellulosic materials for biohydrogen production  

Directory of Open Access Journals (Sweden)

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

Rong Chen; Yong-Zhong Wang; Qiang Liao; Xun Zhu; Teng-Fei Xu

2013-01-01

4

Ethanolic fermentation of pentoses in lignocellulose hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

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

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

1991-12-31

5

The fermentation of lignocellulose hydrolysates with xylose isomerases and yeasts  

Energy Technology Data Exchange (ETDEWEB)

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

Linden, T.

1992-09-01

6

The fermentation of lignocellulose hydrolysates with xylose isomerases and yeasts  

Energy Technology Data Exchange (ETDEWEB)

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

Linden, T.

1992-01-01

7

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

2013-03-14

8

Detoxification of lignocellulosic hydrolysates using sodium borohydride.  

UK PubMed Central (United Kingdom)

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.

Cavka A; Jönsson LJ

2013-05-01

9

Isolation of microorganisms for biological detoxification of lignocellulosic hydrolysates.  

UK PubMed Central (United Kingdom)

Acid pretreatment of lignocellulosic biomass releases furan and phenolic compounds, which are toxic to microorganisms used for subsequent fermentation. In this study, we isolated new microorganisms for depletion of inhibitors in lignocellulosic acid hydrolysates. A sequential enrichment strategy was used to isolate microorganisms from soil. Selection was carried out in a defined mineral medium containing a mixture of ferulic acid (5 mM), 5-hydroxymethylfurfural (5-HMF, 15 mM), and furfural (20 mM) as the carbon and energy sources, followed by an additional transfer into a corn stover hydrolysate (CSH) prepared using dilute acid. Subsequently, based on stable growth on these substrates, six isolates--including five bacteria related to Methylobacterium extorquens, Pseudomonas sp, Flavobacterium indologenes, Acinetobacter sp., Arthrobacter aurescens, and one fungus, Coniochaeta ligniaria--were chosen. All six isolates depleted toxic compounds from defined medium, but only C. ligniaria C8 (NRRL 30616) was effective at eliminating furfural and 5-HMF from CSH. C. ligniaria NRRL 30616 may be useful in developing a bioprocess for inhibitor abatement in the conversion of lignocellulosic biomass to fuels and chemicals.

López MJ; Nichols NN; Dien BS; Moreno J; Bothast RJ

2004-03-01

10

Isolation of microorganisms for biological detoxification of lignocellulosic hydrolysates.  

Science.gov (United States)

Acid pretreatment of lignocellulosic biomass releases furan and phenolic compounds, which are toxic to microorganisms used for subsequent fermentation. In this study, we isolated new microorganisms for depletion of inhibitors in lignocellulosic acid hydrolysates. A sequential enrichment strategy was used to isolate microorganisms from soil. Selection was carried out in a defined mineral medium containing a mixture of ferulic acid (5 mM), 5-hydroxymethylfurfural (5-HMF, 15 mM), and furfural (20 mM) as the carbon and energy sources, followed by an additional transfer into a corn stover hydrolysate (CSH) prepared using dilute acid. Subsequently, based on stable growth on these substrates, six isolates--including five bacteria related to Methylobacterium extorquens, Pseudomonas sp, Flavobacterium indologenes, Acinetobacter sp., Arthrobacter aurescens, and one fungus, Coniochaeta ligniaria--were chosen. All six isolates depleted toxic compounds from defined medium, but only C. ligniaria C8 (NRRL 30616) was effective at eliminating furfural and 5-HMF from CSH. C. ligniaria NRRL 30616 may be useful in developing a bioprocess for inhibitor abatement in the conversion of lignocellulosic biomass to fuels and chemicals. PMID:12908085

López, M J; Nichols, N N; Dien, B S; Moreno, J; Bothast, R J

2003-08-08

11

Production of Succinic Acid for Lignocellulosic Hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

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

Davison, B.H.; Nghiem, J.

2002-06-01

12

Fermentative performance of bacteria and yeasts in lignocellulose hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

The sugar consumption rates and the product formation of yeasts (Saccharomyces cidri NCYC 775, S. cerevisiae NCYC 1047, S.cerevisiae ATCC 4132) and bacteria (Lactobacillus brevis DSM 20054, Lactococcus lactis ssp. lactis ATCC 19435, Escherichia coli ATCC 11303, Zymomonas mobilis ATCC 31821) were investigated in spent sulphite liquor and an enzymatic hydrolysate of steam-pretreated Salix caprea at different pH values in order to elucidate the suitability of the organisms with respect to future genetic engineering approaches. The possible inhibitory action of the two substrates on the investigated microorganisms was also considered. S.cerevisiae emerged as one of the better candidates, owing to its fast sugar consumption rate and efficient ethanol production. (author)

Olsson, Lisbeth; Hahn-Haegerdal, B. (Lund Univ. (Sweden). Dept. of Applied Microbiology)

1993-01-01

13

Fractionation and characterization of brewers' spent grain protein hydrolysates.  

UK PubMed Central (United Kingdom)

Protein hydrolysates with a low and high degree of hydrolysis were enzymatically produced from brewers' spent grain (BSG), the insoluble residue of barley malt resulting from the manufacture of wort in the production of beer. To that end, BSG protein concentrate (BPC), prepared by alkaline extraction of BSG and subsequent acid precipitation, was enzymatically hydrolyzed with Alcalase during both 1.7 and 120 min. Because these hydrolysates contained many different peptides, fractionation of the hydrolysates with graded ammonium sulfate or ethanol precipitation was performed to obtain fractions homogeneous in terms of molecular weight (MW) and hydrophobicity. The emulsifying and foaming capacities of the resultant fractions were determined. MW distributions and surface hydrophobicities of fractions with protein contents exceeding 75% were investigated to determine relationships between technofunctional and physicochemical properties. It was found that the emulsifying and foaming properties are determined by different physicochemical properties of the proteins or peptides. Neither MW nor hydrophobicity alone determines the emulsifying and foaming properties of protein hydrolysates. BSG protein hydrolysates with good emulsifying properties contained less than 40% of fragments with MW exceeding 14 500. Moreover, these hydrolysates had a high surface hydrophobicity. BSG protein hydrolysates with good foaming properties contained less than 10% of material with MW lower than 1700. Hydrolysates with good foaming properties showed low surface hydrophobicities, except for protein hydrolysates with higher levels of protein fragments with MW exceeding 14 500 than of such fragments with MW in a 1700-14 500 range.

Celus I; Brijs K; Delcour JA

2009-06-01

14

Fractionation and characterization of brewers' spent grain protein hydrolysates.  

Science.gov (United States)

Protein hydrolysates with a low and high degree of hydrolysis were enzymatically produced from brewers' spent grain (BSG), the insoluble residue of barley malt resulting from the manufacture of wort in the production of beer. To that end, BSG protein concentrate (BPC), prepared by alkaline extraction of BSG and subsequent acid precipitation, was enzymatically hydrolyzed with Alcalase during both 1.7 and 120 min. Because these hydrolysates contained many different peptides, fractionation of the hydrolysates with graded ammonium sulfate or ethanol precipitation was performed to obtain fractions homogeneous in terms of molecular weight (MW) and hydrophobicity. The emulsifying and foaming capacities of the resultant fractions were determined. MW distributions and surface hydrophobicities of fractions with protein contents exceeding 75% were investigated to determine relationships between technofunctional and physicochemical properties. It was found that the emulsifying and foaming properties are determined by different physicochemical properties of the proteins or peptides. Neither MW nor hydrophobicity alone determines the emulsifying and foaming properties of protein hydrolysates. BSG protein hydrolysates with good emulsifying properties contained less than 40% of fragments with MW exceeding 14 500. Moreover, these hydrolysates had a high surface hydrophobicity. BSG protein hydrolysates with good foaming properties contained less than 10% of material with MW lower than 1700. Hydrolysates with good foaming properties showed low surface hydrophobicities, except for protein hydrolysates with higher levels of protein fragments with MW exceeding 14 500 than of such fragments with MW in a 1700-14 500 range. PMID:19456139

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

2009-06-24

15

Fermentation of lignocellulose hydrolysates with yeasts and xylose isomerase  

Energy Technology Data Exchange (ETDEWEB)

Untreated spent sulfite liquor (SSL) was fermented with five yeasts, Candida tropicalis, Pichia stipitis, Pachysolen tannophilus, Schizosaccharomyces pombe, Saccharomyces cerevisiae, and a co-culture of P. tannophilus and S. cerevisiae, in the presence of commercial xylose (glucose) isomerases and 4.6 mM azide. The highest yield of ethanol, 0.41 g g{sup -1} total sugar, was obtained with S. cerevisiae. The yield based on consumed sugars and per gram cell dry weight was also highest with this yeast. C. tropicalis and P. tannophilus produced considerable amounts of polyoles, mainly xylitol. With P. stipitis sugar uptake was rapidly inhibited in untreated SSL. The presence of azide contributed to the yield by about 0.04 mainly due to the fermentation of stored carbohydrates. The fermentation of hydrogen fluoride-pretreated and acid-hydrolysed wheat straw with S. cerevisiae, xylose isomerase, and azide gave a yield of 0.40 g ethanol g{sup -1} total sugar, In this substrate the xylose utilization was 84% compared with 51% in SSL, which is discussed in relation to the salt sensitivity of xylose isomerases. (author).

Linden, T.; Hahn-Hagerdal, B. (Lund Univ. (Sweden))

1989-09-01

16

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

UK PubMed Central (United Kingdom)

Lignocellulosic biomass has become an important feedstock to mitigate current ethical and economical concerns related to the bio-based production of fuels and chemicals. During the pre-treatment and hydrolysis of the lignocellulosic biomass, a complex mixture of sugars and inhibitors are formed. The inhibitors interfere with microbial growth and product yields. This study uses an adaptive laboratory evolution method called visualizing evolution in real-time (VERT) to uncover the molecular mechanisms associated with tolerance to hydrolysates of lignocellulosic biomass in Saccharomyces cerevisiae. VERT enables a more rational scheme for isolating adaptive mutants for characterization and molecular analyses. Subsequent growth kinetic analyses of the mutants in individual and combinations of common inhibitors present in hydrolysates (acetic acid, furfural, and hydroxymethylfurfural) showed differential levels of resistance to different inhibitors, with enhanced growth rates up to 57%, 12%, 22%, and 24% in hydrolysates, acetic acid, HMF and furfural, respectively. Interestingly, some of the adaptive mutants exhibited reduced fitness in the presence of individual inhibitors, but showed enhanced fitness in the presence of combinations of inhibitors compared to the parental strains. Transcriptomic analysis revealed different mechanisms for resistance to hydrolysates and a potential cross adaptation between oxidative stress and hydrolysates tolerance in several of the mutants. Biotechnol. Bioeng. 2013;110: 2616-2623. © 2013 Wiley Periodicals, Inc.

Almario MP; Reyes LH; Kao KC

2013-10-01

17

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

Science.gov (United States)

Lignocellulosic biomass has become an important feedstock to mitigate current ethical and economical concerns related to the bio-based production of fuels and chemicals. During the pre-treatment and hydrolysis of the lignocellulosic biomass, a complex mixture of sugars and inhibitors are formed. The inhibitors interfere with microbial growth and product yields. This study uses an adaptive laboratory evolution method called visualizing evolution in real-time (VERT) to uncover the molecular mechanisms associated with tolerance to hydrolysates of lignocellulosic biomass in Saccharomyces cerevisiae. VERT enables a more rational scheme for isolating adaptive mutants for characterization and molecular analyses. Subsequent growth kinetic analyses of the mutants in individual and combinations of common inhibitors present in hydrolysates (acetic acid, furfural, and hydroxymethylfurfural) showed differential levels of resistance to different inhibitors, with enhanced growth rates up to 57%, 12%, 22%, and 24% in hydrolysates, acetic acid, HMF and furfural, respectively. Interestingly, some of the adaptive mutants exhibited reduced fitness in the presence of individual inhibitors, but showed enhanced fitness in the presence of combinations of inhibitors compared to the parental strains. Transcriptomic analysis revealed different mechanisms for resistance to hydrolysates and a potential cross adaptation between oxidative stress and hydrolysates tolerance in several of the mutants. Biotechnol. Bioeng. 2013;110: 2616-2623. © 2013 Wiley Periodicals, Inc. PMID:23613173

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

2013-07-11

18

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

UK PubMed Central (United Kingdom)

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.

Jin M; Bothfeld W; Austin S; Sato TK; La Reau A; Li H; Foston M; Gunawan C; Leduc RD; Quensen JF; McGee M; Uppugundla N; Higbee A; Ranatunga R; Donald CW; Bone G; Ragauskas AJ; Tiedje JM; Noguera DR; Dale BE; Zhang Y; Balan V

2013-11-01

19

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

2013-08-14

20

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

Directory of Open Access Journals (Sweden)

Full Text Available 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 In this study, we demonstrate that strain TMB3400 not only converts xylose, but also displays higher tolerance to lignocellulosic hydrolysate during anaerobic batch fermentation as well as 3 times higher in vitro HMF and furfural reduction activity than the control strain USM21. Using laboratory strains producing various levels of Ps-XR, we confirm that Ps-XR is able to reduce HMF both in vitro and in vivo. Ps-XR overexpression increases the in vivo HMF conversion rate by approximately 20%, thereby improving yeast tolerance towards HMF. Further purification of Ps-XR shows that HMF is a substrate inhibitor of the enzyme. Conclusion We demonstrate for the first time that xylose reductase is also able to reduce the furaldehyde compounds that are present in undetoxified lignocellulosic hydrolysates. Possible implications of this newly characterized activity of Ps-XR on lignocellulosic hydrolysate fermentation are discussed.

Almeida João RM; Modig Tobias; Röder Anja; Lidén Gunnar; Gorwa-Grauslund Marie-F

2008-01-01

 
 
 
 
21

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

UK PubMed Central (United Kingdom)

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.

Wang J; Zhang Y; Chen Y; Lin M; Lin Z

2012-12-01

22

Detoxification of model phenolic compounds in lignocellulosic hydrolysates with peroxidase for butanol production from Clostridium beijerinckii.  

Science.gov (United States)

In the present study, we investigated the peroxidase-catalyzed detoxification of model phenolic compounds and evaluated the inhibitory effects of the detoxified solution on butanol production by Clostridium beijerinckii National Collection of Industrial and Marine Bacteria Ltd. 8052. The six phenolic compounds, p-coumaric acid, ferulic acid, 4-hydroxybenzoic acid, vanillic acid, syringaldehyde, and vanillin, were selected as model fermentation inhibitors generated during pretreatment and hydrolysis of lignocellulose. The enzyme reaction was optimized as a function of the reaction conditions of pH, peroxidase concentration, and hydrogen peroxide to substrate ratio. Most of the tested phenolics have a broad optimum pH range of 6.0 to 9. Removal efficiency increased with the molar ratio of H(2)O(2) to each compound up to 0.5-1.25. In the case of p-coumaric acid, ferulic acid, vanillic acid, and vanillin, the removal efficiency was almost 100% with only 0.01 microM of enzyme. The tested phenolic compounds (1 g/L) inhibited cell growth by 64-74%, while completely inhibiting the production of butanol. Although syringaldehyde and vanillin were less toxic on cell growth, the level of inhibition on the butanol production was quite different. The detoxified solution remarkably improved cell growth and surprisingly increased butanol production to the level of the control. Hence, our present study, using peroxidase for the removal of model phenolic compounds, could be applied towards the detoxification of lignocellulosic hydrolysates for butanol fermentation. PMID:19300996

Cho, Dae Haeng; Lee, Yun Jie; Um, Youngsoon; Sang, Byoung-In; Kim, Yong Hwan

2009-03-20

23

Detoxification of model phenolic compounds in lignocellulosic hydrolysates with peroxidase for butanol production from Clostridium beijerinckii.  

UK PubMed Central (United Kingdom)

In the present study, we investigated the peroxidase-catalyzed detoxification of model phenolic compounds and evaluated the inhibitory effects of the detoxified solution on butanol production by Clostridium beijerinckii National Collection of Industrial and Marine Bacteria Ltd. 8052. The six phenolic compounds, p-coumaric acid, ferulic acid, 4-hydroxybenzoic acid, vanillic acid, syringaldehyde, and vanillin, were selected as model fermentation inhibitors generated during pretreatment and hydrolysis of lignocellulose. The enzyme reaction was optimized as a function of the reaction conditions of pH, peroxidase concentration, and hydrogen peroxide to substrate ratio. Most of the tested phenolics have a broad optimum pH range of 6.0 to 9. Removal efficiency increased with the molar ratio of H(2)O(2) to each compound up to 0.5-1.25. In the case of p-coumaric acid, ferulic acid, vanillic acid, and vanillin, the removal efficiency was almost 100% with only 0.01 microM of enzyme. The tested phenolic compounds (1 g/L) inhibited cell growth by 64-74%, while completely inhibiting the production of butanol. Although syringaldehyde and vanillin were less toxic on cell growth, the level of inhibition on the butanol production was quite different. The detoxified solution remarkably improved cell growth and surprisingly increased butanol production to the level of the control. Hence, our present study, using peroxidase for the removal of model phenolic compounds, could be applied towards the detoxification of lignocellulosic hydrolysates for butanol fermentation.

Cho DH; Lee YJ; Um Y; Sang BI; Kim YH

2009-07-01

24

Repetitive succinic acid production from lignocellulose hydrolysates by enhancement of ATP supply in metabolically engineered Escherichia coli.  

UK PubMed Central (United Kingdom)

In this study, repetitive production of succinic acid from lignocellulose hydrolysates by enhancement of ATP supply in metabolically engineered E. coli is reported. Escherichia coli BA305, a pflB, ldhA, ppc, and ptsG deletion strain overexpressing ATP-forming phosphoenolpyruvate (PEP) carboxykinase (PEPCK), produced a final succinic acid concentration of 83 g L(-1) with a high yield of 0.87 g g(-1) total sugar in 36 h of three repetitive fermentations of sugarcane bagasse hydrolysate. Furthermore, simultaneous consumption of glucose and xylose was achieved, and the specific productivity and yield of succinic acid were almost maintained constant during the repetitive fermentations.

Liang L; Liu R; Li F; Wu M; Chen K; Ma J; Jiang M; Wei P; Ouyang P

2013-09-01

25

Kinetic behavior of Candida guilliermondii yeast during xylitol production from Brewer's spent grain hemicellulosic hydrolysate.  

Science.gov (United States)

Brewer's spent grain, the main byproduct of breweries, was hydrolyzed with dilute sulfuric acid to produce a hemicellulosic hydrolysate (containing xylose as the main sugar). The obtained hydrolysate was used as cultivation medium by Candidaguilliermondii yeast in the raw form (containing 20 g/L xylose) and after concentration (85 g/L xylose), and the kinetic behavior of the yeast during xylitol production was evaluated in both media. Assays in semisynthetic media were also performed to compare the yeast performance in media without toxic compounds. According to the results, the kinetic behavior of the yeast cultivated in raw hydrolysate was as effective as in semisynthetic medium containing 20 g/L xylose. However, in concentrated hydrolysate medium, the xylitol production efficiency was 30.6% and 42.6% lower than in raw hydrolysate and semisynthetic medium containing 85 g/L xylose, respectively. In other words, the xylose-to-xylitol bioconversion from hydrolysate medium was strongly affected when the initial xylose concentration was increased; however, similar behavior did not occur from semisynthetic media. The lowest efficiency of xylitol production from concentrated hydrolysate can be attributed to the high concentration of toxic compounds present in this medium, resulting from the hydrolysate concentration process. PMID:16080723

Mussatto, Solange I; Dragone, Giuliano; Roberto, Inês C

26

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

UK PubMed Central (United Kingdom)

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

Celus I; Brijs K; Delcour JA

2007-10-01

27

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

Science.gov (United States)

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

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

2012-11-02

28

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

UK PubMed Central (United Kingdom)

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

Quevedo-Hidalgo B; Monsalve-Marín F; Narváez-Rincón PC; Pedroza-Rodríguez AM; Velásquez-Lozano ME

2013-03-01

29

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 1:10g/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

2013-07-30

30

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

UK PubMed Central (United Kingdom)

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 1:10g/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.

Zhang X; Ye X; Guo B; Finneran KT; Zilles JL; Morgenroth E

2013-11-01

31

Development of a D-xylose fermenting and inhibitor tolerant industrial Saccharomyces cerevisiae strain with high performance in lignocellulose hydrolysates using metabolic and evolutionary engineering  

Science.gov (United States)

Background The production of bioethanol from lignocellulose hydrolysates requires a robust, D-xylose-fermenting and inhibitor-tolerant microorganism as catalyst. The purpose of the present work was to develop such a strain from a prime industrial yeast strain, Ethanol Red, used for bioethanol production. Results An expression cassette containing 13 genes including Clostridium phytofermentans XylA, encoding D-xylose isomerase (XI), and enzymes of the pentose phosphate pathway was inserted in two copies in the genome of Ethanol Red. Subsequent EMS mutagenesis, genome shuffling and selection in D-xylose-enriched lignocellulose hydrolysate, followed by multiple rounds of evolutionary engineering in complex medium with D-xylose, gradually established efficient D-xylose fermentation. The best-performing strain, GS1.11-26, showed a maximum specific D-xylose consumption rate of 1.1 g/g DW/h in synthetic medium, with complete attenuation of 35 g/L D-xylose in about 17 h. In separate hydrolysis and fermentation of lignocellulose hydrolysates of Arundo donax (giant reed), spruce and a wheat straw/hay mixture, the maximum specific D-xylose consumption rate was 0.36, 0.23 and 1.1 g/g DW inoculum/h, and the final ethanol titer was 4.2, 3.9 and 5.8% (v/v), respectively. In simultaneous saccharification and fermentation of Arundo hydrolysate, GS1.11-26 produced 32% more ethanol than the parent strain Ethanol Red, due to efficient D-xylose utilization. The high D-xylose fermentation capacity was stable after extended growth in glucose. Cell extracts of strain GS1.11-26 displayed 17-fold higher XI activity compared to the parent strain, but overexpression of XI alone was not enough to establish D-xylose fermentation. The high D-xylose consumption rate was due to synergistic interaction between the high XI activity and one or more mutations in the genome. The GS1.11-26 had a partial respiratory defect causing a reduced aerobic growth rate. Conclusions An industrial yeast strain for bioethanol production with lignocellulose hydrolysates has been developed in the genetic background of a strain widely used for commercial bioethanol production. The strain uses glucose and D-xylose with high consumption rates and partial cofermentation in various lignocellulose hydrolysates with very high ethanol yield. The GS1.11-26 strain shows highly promising potential for further development of an all-round robust yeast strain for efficient fermentation of various lignocellulose hydrolysates.

2013-01-01

32

Development of a D-xylose fermenting and inhibitor tolerant industrial Saccharomyces cerevisiae strain with high performance in lignocellulose hydrolysates using metabolic and evolutionary engineering.  

UK PubMed Central (United Kingdom)

BACKGROUND: The production of bioethanol from lignocellulose hydrolysates requires a robust, D-xylose-fermenting and inhibitor-tolerant microorganism as catalyst. The purpose of the present work was to develop such a strain from a prime industrial yeast strain, Ethanol Red, used for bioethanol production. RESULTS: An expression cassette containing 13 genes including Clostridium phytofermentans XylA, encoding D-xylose isomerase (XI), and enzymes of the pentose phosphate pathway was inserted in two copies in the genome of Ethanol Red. Subsequent EMS mutagenesis, genome shuffling and selection in D-xylose-enriched lignocellulose hydrolysate, followed by multiple rounds of evolutionary engineering in complex medium with D-xylose, gradually established efficient D-xylose fermentation. The best-performing strain, GS1.11-26, showed a maximum specific D-xylose consumption rate of 1.1 g/g DW/h in synthetic medium, with complete attenuation of 35 g/L D-xylose in about 17 h. In separate hydrolysis and fermentation of lignocellulose hydrolysates of Arundo donax (giant reed), spruce and a wheat straw/hay mixture, the maximum specific D-xylose consumption rate was 0.36, 0.23 and 1.1 g/g DW inoculum/h, and the final ethanol titer was 4.2, 3.9 and 5.8% (v/v), respectively. In simultaneous saccharification and fermentation of Arundo hydrolysate, GS1.11-26 produced 32% more ethanol than the parent strain Ethanol Red, due to efficient D-xylose utilization. The high D-xylose fermentation capacity was stable after extended growth in glucose. Cell extracts of strain GS1.11-26 displayed 17-fold higher XI activity compared to the parent strain, but overexpression of XI alone was not enough to establish D-xylose fermentation. The high D-xylose consumption rate was due to synergistic interaction between the high XI activity and one or more mutations in the genome. The GS1.11-26 had a partial respiratory defect causing a reduced aerobic growth rate. CONCLUSIONS: An industrial yeast strain for bioethanol production with lignocellulose hydrolysates has been developed in the genetic background of a strain widely used for commercial bioethanol production. The strain uses glucose and D-xylose with high consumption rates and partial cofermentation in various lignocellulose hydrolysates with very high ethanol yield. The GS1.11-26 strain shows highly promising potential for further development of an all-round robust yeast strain for efficient fermentation of various lignocellulose hydrolysates.

Demeke MM; Dietz H; Li Y; Foulquié-Moreno MR; Mutturi S; Deprez S; Den Abt T; Bonini BM; Liden G; Dumortier F; Verplaetse A; Boles E; Thevelein JM

2013-01-01

33

Role of Pretreatment and Conditioning Processes on Toxicity of Lignocellulosic Biomass Hydrolysates  

Energy Technology Data Exchange (ETDEWEB)

The Department of Energy's Office of the Biomass Program has set goals of making ethanol cost competitive by 2012 and replacing 30% of 2004 transportation supply with biofuels by 2030. Both goals require improvements in conversions of cellulosic biomass to sugars as well as improvements in fermentation rates and yields. Current best pretreatment processes are reasonably efficient at making the cellulose/hemicellulose/lignin matrix amenable to enzymatic hydrolysis and fermentation, but they release a number of toxic compounds into the hydrolysate which inhibit the growth and ethanol productivity of fermentation organisms. Conditioning methods designed to reduce the toxicity of hydrolysates are effective, but add to process costs and tend to reduce sugar yields, thus adding significantly to the final cost of production. Reducing the cost of cellulosic ethanol production will likely require enhanced understanding of the source and mode of action of hydrolysate toxic compounds, the means by which some organisms resist the actions of these compounds, and the methodology and mechanisms for conditioning hydrolysate to reduce toxicity. This review will provide an update on the state of knowledge in these areas and can provide insights useful for the crafting of hypotheses for improvements in pretreatment, conditioning, and fermentation organisms.

Pienkos, P. T.; Zhang, M.

2009-01-01

34

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

Science.gov (United States)

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

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

2007-09-27

35

Inhibition of growth of Zymomonas mobilis by model compounds found in lignocellulosic hydrolysates.  

UK PubMed Central (United Kingdom)

BACKGROUND: During the pretreatment of biomass feedstocks and subsequent conditioning prior to saccharification, many toxic compounds are produced or introduced which inhibit microbial growth and in many cases, production of ethanol. An understanding of the toxic effects of compounds found in hydrolysate is critical to improving sugar utilization and ethanol yields in the fermentation process. In this study, we established a useful tool for surveying hydrolysate toxicity by measuring growth rates in the presence of toxic compounds, and examined the effects of selected model inhibitors of aldehydes, organic and inorganic acids (along with various cations), and alcohols on growth of Zymomonas mobilis 8b (a ZM4 derivative) using glucose or xylose as the carbon source. RESULTS: Toxicity strongly correlated to hydrophobicity in Z. mobilis, which has been observed in Escherichia coli and Saccharomyces cerevisiae for aldehydes and with some exceptions, organic acids. We observed Z. mobilis 8b to be more tolerant to organic acids than previously reported, although the carbon source and growth conditions play a role in tolerance. Growth in xylose was profoundly inhibited by monocarboxylic organic acids compared to growth in glucose, whereas dicarboxylic acids demonstrated little or no effects on growth rate in either substrate. Furthermore, cations can be ranked in order of their toxicity, Ca++ >?>?Na+?>?NH4+?>?K+. HMF (5-hydroxymethylfurfural), furfural and acetate, which were observed to contribute to inhibition of Z. mobilis growth in dilute acid pretreated corn stover hydrolysate, do not interact in a synergistic manner in combination. We provide further evidence that Z. mobilis 8b is capable of converting the aldehydes furfural, vanillin, 4-hydroxybenzaldehyde and to some extent syringaldehyde to their alcohol forms (furfuryl, vanillyl, 4-hydroxybenzyl and syringyl alcohol) during fermentation. CONCLUSIONS: Several key findings in this report provide a mechanism for predicting toxic contributions of inhibitory components of hydrolysate and provide guidance for potential process development, along with potential future strain improvement and tolerance strategies.

Franden MA; Pilath HM; Mohagheghi A; Pienkos PT; Zhang M

2013-01-01

36

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

Science.gov (United States)

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

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

2010-01-08

37

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

UK PubMed Central (United Kingdom)

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.

Liu S; Bischoff KM; Leathers TD; Qureshi N; Rich JO; Hughes SR

2013-09-01

38

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

UK PubMed Central (United Kingdom)

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 was also analyzed. Chemical treatments successfully produced several different LCYC based on BSG. The highest cellulose content in LCYC was achieved upon application of caustic (NaOH) treatment during 40 min. Either caustic or combined acid-caustic treatments predominately generated hydrophobic, negatively charged LCYC. The feasibility of using BSG for LCYC production is strengthened by the fact that added-value byproduct can be extracted before the chemical treatments are applied.

Pires EJ; Ruiz HA; Teixeira JA; Vicente AA

2012-06-01

39

Co-expression of TAL1 and ADH1 in recombinant xylose-fermenting Saccharomyces cerevisiae improves ethanol production from lignocellulosic hydrolysates in the presence of furfural.  

UK PubMed Central (United Kingdom)

Lignocellulosic biomass dedicated to bioethanol production usually contains pentoses and inhibitory compounds such as furfural that are not well tolerated by Saccharomyces cerevisiae. Thus, S. cerevisiae strains with the capability of utilizing both glucose and xylose in the presence of inhibitors such as furfural are very important in industrial ethanol production. Under the synergistic conditions of transaldolase (TAL) and alcohol dehydrogenase (ADH) overexpression, S. cerevisiae MT8-1X/TAL-ADH was able to produce 1.3-fold and 2.3-fold more ethanol in the presence of 70 mM furfural than a TAL-expressing strain and a control strain, respectively. We also tested the strains' ability by mimicking industrial ethanol production from hemicellulosic hydrolysate containing fermentation inhibitors, and ethanol production was further improved by 16% when using MT8-1X/TAL-ADH compared to the control strain. Transcript analysis further revealed that besides the pentose phosphate pathway genes TKL1 and TAL1, ADH7 was also upregulated in response to furfural stress, which resulted in higher ethanol production compared to the TAL-expressing strain. The improved capability of our modified strain was based on its capacity to more quickly reduce furfural in situ resulting in higher ethanol production. The co-expression of TAL/ADH genes is one crucial strategy to fully utilize undetoxified lignocellulosic hydrolysate, leading to cost-competitive ethanol production.

Hasunuma T; Ismail KS; Nambu Y; Kondo A

2013-08-01

40

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

UK PubMed Central (United Kingdom)

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

Qiao JJ; Zhang YF; Sun LF; Liu WW; Zhu HJ; Zhang Z

2011-09-01

 
 
 
 
41

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

Science.gov (United States)

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

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

2013-10-24

42

Dynamic Changes in Xylanases and ?-1,4-Endoglucanases Secreted by Aspergillus niger An-76 in Response to Hydrolysates of Lignocellulose Polysaccharide.  

UK PubMed Central (United Kingdom)

Aspergillus niger is an effective secretor of glycoside hydrolases that facilitate the saprophytic lifestyle of the fungus by degrading plant cell wall polysaccharides. In the present study, a series of dynamic zymography assays were applied to quantify the secreted glycoside hydrolases of A. niger cultured in media containing different carbon sources. Differences in the diversity and concentrations of polysaccharide hydrolysates dynamically regulated the secretion of glycoside hydrolases. The secretion of ?-1,4-endoglucanase isozymes was observed to lag at least 24 h behind, rather than coincide with, the secretion of xylanase isozymes. Low concentrations of xylose could induce many endoxylanases (such as Xyn1/XynA, Xyn2, and Xyn3/XynB). High concentrations of xylose could sustain the induction of Xyn2 and Xyn3/XynB but repress Xyn1/XynA (GH10 endoxylanase), which has a broad substrate specificity, and also triggers the low-level secretion of Egl3/EglA, which also has a broad substrate specificity. Mixed polysaccharide hydrolysates sustained the induction of Egl1, whereas the other ?-1,4-endoglucanases were sustainably induced by the specific polysaccharide hydrolysates released during the hydrolysis process (such as Egl2 and Egl4). These results indicate that the secretion of glycoside hydrolases may be specifically regulated by the production of polysaccharide hydrolysates released during the process of biomass degradation.

Xing S; Li G; Sun X; Ma S; Chen G; Wang L; Gao P

2013-07-01

43

Dynamic Changes in Xylanases and ?-1,4-Endoglucanases Secreted by Aspergillus niger An-76 in Response to Hydrolysates of Lignocellulose Polysaccharide.  

Science.gov (United States)

Aspergillus niger is an effective secretor of glycoside hydrolases that facilitate the saprophytic lifestyle of the fungus by degrading plant cell wall polysaccharides. In the present study, a series of dynamic zymography assays were applied to quantify the secreted glycoside hydrolases of A. niger cultured in media containing different carbon sources. Differences in the diversity and concentrations of polysaccharide hydrolysates dynamically regulated the secretion of glycoside hydrolases. The secretion of ?-1,4-endoglucanase isozymes was observed to lag at least 24 h behind, rather than coincide with, the secretion of xylanase isozymes. Low concentrations of xylose could induce many endoxylanases (such as Xyn1/XynA, Xyn2, and Xyn3/XynB). High concentrations of xylose could sustain the induction of Xyn2 and Xyn3/XynB but repress Xyn1/XynA (GH10 endoxylanase), which has a broad substrate specificity, and also triggers the low-level secretion of Egl3/EglA, which also has a broad substrate specificity. Mixed polysaccharide hydrolysates sustained the induction of Egl1, whereas the other ?-1,4-endoglucanases were sustainably induced by the specific polysaccharide hydrolysates released during the hydrolysis process (such as Egl2 and Egl4). These results indicate that the secretion of glycoside hydrolases may be specifically regulated by the production of polysaccharide hydrolysates released during the process of biomass degradation. PMID:23900618

Xing, Sheng; Li, Guoli; Sun, Xulu; Ma, Su; Chen, Guanjun; Wang, Lushan; Gao, Peiji

2013-07-31

44

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

45

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; Alriksson Björn; Nilvebrant Nils-Olof

2013-01-01

46

Bioconversion of lignocellulose: inhibitors and detoxification.  

UK PubMed Central (United Kingdom)

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 LJ; Alriksson B; Nilvebrant NO

2013-01-01

47

Bioethanol from Lignocellulosic Biomass: A review  

Directory of Open Access Journals (Sweden)

Full Text Available The perspectives of biobased fuels as options for partial fossil fuels substitution has encouraged research on the availability of biomass feedstock and development of efficient conversion processes. In the case of fuels for transport, bioconversion of lignocellulosic materials to ethanol has been recognized as one of the promising routes of producing competitive substitutes to gasoline.Lignocellulose is the most abundant natural renewable resource and is one of the preferred choices for the production of bioethanol. As a substrate for bioethanol production it has a barrier in its complex structure, which resists hydrolysis. For lignocellulose to be amenable to fermentation, treatments are necessary that release monomeric sugars, which can be converted to ethanol by microbial fermentation. The current state of the art on acid and enzymatic hydrolysis of lignocellulose and subsequent microbial fermentation to ethanol are described in this work. Approaches for detoxification of the lignocellulose hydrolysate for effective fermentation to ethanol are also described

Eufrozina Niga

2010-01-01

48

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

Directory of Open Access Journals (Sweden)

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

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

2013-01-01

49

Ethanol production from corn cob hydrolysates by Escherichia coli KO11.  

Science.gov (United States)

Corn cob hydrolysates, with xylose as the dominant sugar, were fermented to ethanol by recombinant Escherichia coli KO11. When inoculum was grown on LB medium containing glucose, fermentation of the hydrolysate was completed in 163 h and ethanol yield was 0.50 g ethanol/g sugar. When inoculum was grown on xylose, ethanol yield dropped, but fermentation was faster (113 h). Hydrolysate containing 72.0 g/l xylose and supplemented with 20.0 g/l rice bran was readily fermented, producing 36.0 g/l ethanol within 70 h. Maximum ethanol concentrations were not higher for fermentations using higher cellular concentration inocula. A simulation of an industrial process integrating pentose fermentation by E. coli and hexose fermentation by yeast was carried out. At the first step, E. coli fermented the hydrolysate containing 85.0 g/l xylose, producing 40.0 g/l ethanol in 94 h. Baker's yeast and sucrose (150.0 g/l) were then added to the spent fermentation broth. After 8 h of yeast fermentation, the ethanol concentration reached 104.0 g/l. This two-stage fermentation can render the bioconversion of lignocellulose to ethanol more attractive due to increased final alcohol concentration. PMID:12242633

de Carvalho Lima, K G; Takahashi, C M; Alterthum, F

2002-09-01

50

Ethanol production from corn cob hydrolysates by Escherichia coli KO11.  

UK PubMed Central (United Kingdom)

Corn cob hydrolysates, with xylose as the dominant sugar, were fermented to ethanol by recombinant Escherichia coli KO11. When inoculum was grown on LB medium containing glucose, fermentation of the hydrolysate was completed in 163 h and ethanol yield was 0.50 g ethanol/g sugar. When inoculum was grown on xylose, ethanol yield dropped, but fermentation was faster (113 h). Hydrolysate containing 72.0 g/l xylose and supplemented with 20.0 g/l rice bran was readily fermented, producing 36.0 g/l ethanol within 70 h. Maximum ethanol concentrations were not higher for fermentations using higher cellular concentration inocula. A simulation of an industrial process integrating pentose fermentation by E. coli and hexose fermentation by yeast was carried out. At the first step, E. coli fermented the hydrolysate containing 85.0 g/l xylose, producing 40.0 g/l ethanol in 94 h. Baker's yeast and sucrose (150.0 g/l) were then added to the spent fermentation broth. After 8 h of yeast fermentation, the ethanol concentration reached 104.0 g/l. This two-stage fermentation can render the bioconversion of lignocellulose to ethanol more attractive due to increased final alcohol concentration.

de Carvalho Lima KG; Takahashi CM; Alterthum F

2002-09-01

51

Pervaporation of ethanol from lignocellulosic fermentation broth.  

UK PubMed Central (United Kingdom)

Pervaporation can be applied in ethanol production from lignocellulosic biomass. Hydrophobic pervaporation, using a commercial PDMS membrane, was employed to concentrate the ethanol produced by fermentation of lignocellulosic hydrolysate. To our knowledge, this is the first report describing this. Pervaporation carried out with three different lignocellulosic fermentation broths reduced the membrane performance by 17-20% as compared to a base case containing only 3 wt.% ethanol in water. The membrane fouling caused by these fermentation broths was irreversible. Solutions containing model lignocellulosic components were tested during pervaporation at the same conditions. A total flux decrease of 12-15%, as compared to the base case, was observed for each component except for furfural. Catechol was found to be most fouling component whereas furfural permeated through the membrane and increased the total flux. The membrane selectivity increased in the presence of fermentation broth but remained unchanged for all selected components.

Gaykawad SS; Zha Y; Punt PJ; van Groenestijn JW; van der Wielen LA; Straathof AJ

2013-02-01

52

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

53

Adaptation of Dekkera bruxellensis to lignocellulose-based substrate.  

UK PubMed Central (United Kingdom)

Adaptation of Dekkera bruxellensis to lignocellulose hydrolysate was investigated. Cells of D. bruxellensis were grown for 72 and 192 hours in batch and continuous culture, respectively (adapted cells). Cultivations in semisynthetic medium were run as controls (non-adapted cells). To test the adaptation, cells from these cultures were reinoculated in the lignocellulose medium and growth and ethanol production characteristics were monitored. Cells adapted to lignocellulose hydrolysate had shorter lag phase, grew faster and produced higher ethanol concentration as compared to non-adapted cells. A stability test showed that after cultivation in rich medium cells partially lost the adapted phenotype but still showed faster growth and higher ethanol production as compared to non-adapted cells. Since alcohol dehydrogenase genes have been described to be involved in the adaptation to furfural in Saccharomyces cerevisiae an analogous mechanism of adaptation to lignocelluloses hydrolysate of D. bruxellensis was hypothesized. However, gene expression analysis showed that genes homologous to S. cerevisiae ADH1 were not involved in the adaptation to lignocelluloses hydrolysate in D. bruxellensis. This article is protected by copyright. All rights reserved.

Tiukova I; de Barros Pita W; Sundell D; Momeni MH; Horn SJ; Ståhlberg J; de Morais MA Jr; Passoth V

2013-08-01

54

Biohydrogen Production Using Hydrolysates Of Palm Oil Mill Effluent (Pome)  

Directory of Open Access Journals (Sweden)

Full Text Available Dark hydrogen fermentation using lignocellulosic biomass has been widely reported. In this study, raw and hydrolysed Palm Oil Mill Effluent (POME) were used as substrates to produce hydrogen by POME sludge in 30-mL serum bottle. A higher cumulative volume of hydrogen of 1439 mL H2.L-1 POME was obtained from hydrolysed POME as compared to raw POME. Fermentation process was then carried out in 2-L stirred tank bioreactor using hydrolysed POME as medium and it was found that a two-fold of hydrogen volumetric rate increase was achieved.

N.A. Khaleb; J.Md. Jahim; S. Ahmad Kamal

2012-01-01

55

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.

56

Hydrolysis of lignocellulose with sulfur dioxide. Final report; Hydrolys av lignocellulosa med svaveldioxid. Slutrapport  

Energy Technology Data Exchange (ETDEWEB)

The aim of this project was to investigate the possibility of using sulfur dioxide as the hydrolysing agent in saccharification of lignocellulose. The sulfur content in the hydrolysates was 0.5-2 % of the dry matter. When the sugar have fermented to ethanol and been distilled, the sulfur content in the remaining draff ought to be higher, which means that the sulfur content in the hydrolysate is a serious obstacle to utilization of the draffs heating value in a boiler. The sulfur content in the solid hydrolysate remains is low, which makes this material a suitable fuel 7 figs, 9 tabs

Andersson, Peter [Kemira Kemi AB (Sweden)

1998-08-01

57

Pretreatments of lignocellulosic feedstock for bioethanol production  

Directory of Open Access Journals (Sweden)

Full Text Available The use of renewable energy sources (biofuels), either as a component in the conventional fossil fuels, gasoline and diesel, or as a pure biofuel, contributes to energy saving and decrease of total CO2 emission. The use of bioethanol mixed with gasoline significantly decreases gasoline consumption and contributes to environment protection. One of the problems in the production of bioethanol is the availability of sugar and starch based feedstock used for its production. However, lignocellulosic feedstocks are becoming more significant in the production of bioethanol due to their availability and low cost. The aim of this study is to point out the advantages and shortcomings of pretreatment processes and hydrolyses of lignocellulosic feedstocks that precede their fermentation to bioethanol.

Predojevi? Zlatica J.

2010-01-01

58

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

Directory of Open Access Journals (Sweden)

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

Albers Eva; Johansson Emma; Franzén Carl Johan; Larsson Christer

2011-01-01

59

PROCESS FOR ALCOHOLIC FERMENTATION OF LIGNOCELLULOSIC BIOMASS  

UK PubMed Central (United Kingdom)

A process for the production of ethanol wherein a hydrolyzed lignocellulosic biomass is fermented in the presence of a stillage residue. The fermentation of cellulosic hydrolysates is improved by adding prior to and/or during fermentation a stillage residue side stream from a corn starch-to-ethanol process as a nutrient source for the yeast organisms used in the fermentation. Stillage residues from the grain dry mill ethanol producing process, including the whole stillage, wet cake, thin stillage, and/or syrup are added to assist as a nitrogen and nutrient source for the fermentive processes. The stillage residue is produced by any grain-to-ethanol process.

BENSON ROBERT ASHLEY COOPER; BENECH REGIS-OLIVIER

60

A comparative study of the hydrolysis of gamma irradiated lignocelluloses  

Directory of Open Access Journals (Sweden)

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

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

2009-01-01

 
 
 
 
61

Ethanol production from lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

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

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

2001-01-01

62

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

UK PubMed Central (United Kingdom)

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.

Harner NK; Bajwa PK; Habash MB; Trevors JT; Austin GD; Lee H

2013-10-01

63

Enzymatic conversion of lignocellulose into fermentable sugars : challenges and opportunities  

DEFF Research Database (Denmark)

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

JØrgensen, Henning; Kristensen, Jan Bach

2007-01-01

64

Production of ethanol from sugars and lignocellulosic biomass by Thermoanaerobacter J1 isolated from a hot spring in Iceland.  

UK PubMed Central (United Kingdom)

Thermophilic bacteria have gained increased attention as candidates for bioethanol production from lignocellulosic biomass. This study investigated ethanol production by Thermoanaerobacter strain J1 from hydrolysates made from lignocellulosic biomass in batch cultures. The effect of increased initial glucose concentration and the partial pressure of hydrogen on end product formation were examined. The strain showed a broad substrate spectrum, and high ethanol yields were observed on glucose (1.70 mol/mol) and xylose (1.25 mol/mol). Ethanol yields were, however, dramatically lowered by adding thiosulfate or by cocultivating strain J1 with a hydrogenotrophic methanogen with acetate becoming the major end product. Ethanol production from 4.5 g/L of lignocellulosic biomass hydrolysates (grass, hemp stem, wheat straw, newspaper, and cellulose) pretreated with acid or alkali and the enzymes Celluclast and Novozymes 188 was investigated. The highest ethanol yields were obtained on cellulose (7.5 mM·g(-1)) but the lowest on straw (0.8 mM·g(-1)). Chemical pretreatment increased ethanol yields substantially from lignocellulosic biomass but not from cellulose. The largest increase was on straw hydrolysates where ethanol production increased from 0.8 mM·g(-1) to 3.3 mM·g(-1) using alkali-pretreated biomass. The highest ethanol yields on lignocellulosic hydrolysates were observed with hemp hydrolysates pretreated with acid, 4.2 mM·g(-1).

Jessen JE; Orlygsson J

2012-01-01

65

ASPIC WITH GELATINE HYDROLYSATE  

UK PubMed Central (United Kingdom)

An aspic with gelatine hydrolysate based on gelatine jelly contains 1-20 % by weight gelatine hydrolysate having a mean molecular weight from 3000 to 5000 d, as compared with gelatine jelly having a mean molecular weight of 100.000 d. The aspic thus retains its typical jelly-like properties even after deep-freezing below -20 °C followed by thawing.

MARGGRANDER Kurt

66

Prehydrolysis of lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions.

Torget, Robert W. (Littleton, CO); Kadam, Kiran L. (Golden, CO); Hsu, Teh-An (Golden, CO); Philippidis, George P. (Highlands Ranch, CO); Wyman, Charles E. (Lakewood, CO)

1996-01-01

67

Prehydrolysis of lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions.

Torget, Robert W. (Littleton, CO); Kadam, Kiran L. (Golden, CO); Hsu, Teh-An (Golden, CO); Philippidis, George P. (Highlands Ranch, CO); Wyman, Charles E. (Lakewood, CO)

1998-01-01

68

Prehydrolysis of lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions.

Torget, Robert W. (Littleton, CO); Kadam, Kiran L. (Golden, CO); Hsu, Teh-An (Golden, CO); Philippidis, George P. (Highlands Ranch, CO); Wyman, Charles E. (Lakewood, CO)

1995-01-01

69

Prehydrolysis of lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions. 7 figs.

Torget, R.W.; Kadam, K.L.; Hsu, T.A.; Philippidis, G.P.; Wyman, C.E.

1996-04-02

70

Prehydrolysis of lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions. 7 figs.

Torget, R.W.; Kadam, K.L.; Hsu, T.A.; Philippidis, G.P.; Wyman, C.E.

1995-06-13

71

Prehydrolysis of lignocellulose  

Energy Technology Data Exchange (ETDEWEB)

The invention relates to the prehydrolysis of lignocellulose by passing an acidic or alkaline solution through solid lignocellulosic particles with removal of soluble components as they are formed. The technique permits a less severe combination of pH, temperature and time than conventional prehydrolysis. Furthermore, greater extraction of both hemicellulose and lignin occurs simultaneously in the same reactor and under the same conditions. 7 figs.

Torget, R.W.; Kadam, K.L.; Hsu, T.A.; Philippidis, G.P.; Wyman, C.E.

1998-01-06

72

Biotechnological valorization potential indicator for lignocellulosic materials.  

Science.gov (United States)

This report introduces the biotechnological valorization potential indicator (BVPI) concept, a metric to measure the degree of suitability of lignocellulosic materials to be used as feedstock in a biorefinery framework. This indicator groups the impact of the main factors influencing upgrade-ability, both the biological/chemical nature of the materials, and the economical, technological and geographical factors. The BVPI was applied to the identification of the most relevant opportunities and constraints pertaining to the lignocellulosic by-products from the Portuguese agro-industrial cluster. Several by-products were identified with a high valorization potential, e.g., rice husks, brewery's spent grain, tomato pomace, carob pulp, de-alcoholized grape bagasse, and extracted olive bagasse, that would greatly benefit from the further development of specific biotechnology processes, specifically concerning the upgrade of their hemicellulosic fraction. PMID:18061896

Duarte, Luís C; Esteves, Maria P; Carvalheiro, Florbela; Gírio, Francisco M

2007-12-01

73

Electricity generation by microbial fuel cells fuelled with wheat straw hydrolysate  

DEFF Research Database (Denmark)

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

Thygesen, Anders; Poulsen, Finn Willy

2011-01-01

74

Bioconversion of lignocellulosics  

Energy Technology Data Exchange (ETDEWEB)

During the 3 years from 1986 to 1988, two International Energy Agency projects, CPD 2 (Pretreatment of Lignocellulosics) and CPD 5 (Conversion of C5, Sugars to Ethanol) were combined to form Task IV -Bioconversion of Lignocellulosics. Two meetings were held, the first in Graz, Austria in 1986 and the second in Ottawa, Canada in 1988. Proceedings from each of these meetings were distributed among the participants. Round-robin tests on the chemical analysis of pretreated lignocellulosic substrates and the enzymatic hydrolysis of these substrates were carried out by the network participants. Industrial groups from member countries were invited to participate at the Ottawa meeting. Various economic models were presented to determine the techno-economic factors influencing the commercial viability of a bioconversion process. The success of the network was reflected in the attendance at the meetings, the excellent rapport of the participants and the useful information arising from the round-robin comparisons. (author).

Saddler, J.N. (Forintek Canada Corp., Ottawa, ON (Canada). Eastern Forest Products Lab.); Mackie, K. (Forest Research Inst., Rotorua (NZ))

1990-01-01

75

gTME for improved adaptation of Saccharomyces cerevisiae to corn cob acid hydrolysate.  

UK PubMed Central (United Kingdom)

Global transcription machinery engineering was employed to engineer xylose metabolism, tolerance and adaptation to lignocellulosic hydrolysates. Mutation of the transcription factor spt15 was introduced by error-prone PCR, then transformed the recombinant plasmid pYX212-spt15 into Saccharomyces cerevisiae YPH499 which was not able to grow on xylose, and screened on media using lignocellulosic hydrolysates as the sole carbon source. The maximum sugar yield was obtained by the hydrolysis form with 3% HCl (m/v) using autoclaving at 120 °C, for 2 h with a solid to liquid ratio of 1:10. The corn cob hydrolysate contained 68.41 g/L xylose and 7.67 g/L glucose. The recombinant strain showed modest growth rate when cultured in the cellulosic hydrolysates with different pretreatment and pH conditions. The results showed that spt15-29 reached the maximum xylose and glucose utilization of 65.7% and 87.0%, respectively, the maximum ethanol concentration was 11.9 g/L, after 71 h, using the acid hydrolysate with the initial pH of 5.

Liu H; Liu K; Yan M; Xu L; Ouyang P

2011-08-01

76

Comparative Proteomic Analysis of Tolerance and Adaptation of Ethanologenic Saccharomyces cerevisiae to Furfural, a Lignocellulosic Inhibitory Compound? †  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The molecular mechanism involved in tolerance and adaptation of ethanologenic Saccharomyces cerevisiae to inhibitors (such as furfural, acetic acid, and phenol) represented in lignocellulosic hydrolysate is still unclear. Here, 18O-labeling-aided shotgun comparative proteome analysis was applied to ...

Lin, Feng-Ming; Qiao, Bin; Yuan, Ying-Jin

77

Kinetic studies on the product inhibition of enzymatic lignocellulose hydrolysis.  

UK PubMed Central (United Kingdom)

In order to understand the product inhibition of enzymatic lignocellulose hydrolysis, the enzymatic hydrolysis of pretreated rice straw was carried out over an enzyme loading range of 2 to 30 FPU/g substrate, and the inhibition of enzymatic hydrolysis was analyzed kinetically based on the reducing sugars produced. It was shown that glucose, xylose, and arabinose were the main reducing sugar components contained in the hydrolysate. The mass ratio of glucose, xylose, and arabinose to the total reducing sugars was almost constant at 52.0%, 29.7% and 18.8%, respectively, in the enzyme loading range. The reducing sugars exerted competitive inhibitory interferences to the enzymatic hydrolysis. Glucose, xylose, and arabinose had a dissociation constant of 1.24, 0.54 and 0.33 g/l, respectively. The inhibitory interferences by reducing sugars were superimposed on the enzymatic hydrolysis. The enzymatic hydrolysis could be improved by the removal of the produced reducing sugars from hydrolysate.

Miao Y; Chen JY; Jiang X; Huang Z

2012-05-01

78

A comparative study of the hydrolysis of gamma irradiated lignocelluloses  

Scientific Electronic Library Online (English)

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

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

2009-06-01

79

Performance of a newly developed integrant of Zymomonas mobilis for ethanol production on corn stover hydrolysate.  

UK PubMed Central (United Kingdom)

Efficient conversion of lignocellulosic biomass requires biocatalysts able to tolerate inhibitors produced by many pretreatment processes. Recombinant Zymomonas mobilis 8b, a recently developed integrant of Zymomonas mobilis 31821(pZB5), tolerated acetic acid up to 16 g l(-1) and achieved 82%-87% (w/w) ethanol yields from pure glucose/xylose solutions at pH 6 and temperatures of 30 degrees C and 37 degrees C. An ethanol yield of 85% (w/w) was achieved on glucose/xylose from hydrolysate produced by dilute sulfuric acid pretreatment of corn stover after an overliming' process was used to improve hydrolysate fermentability.

Mohagheghi A; Dowe N; Schell D; Chou YC; Eddy C; Zhang M

2004-02-01

80

Performance of a newly developed integrant of Zymomonas mobilis for ethanol production on corn stover hydrolysate.  

Science.gov (United States)

Efficient conversion of lignocellulosic biomass requires biocatalysts able to tolerate inhibitors produced by many pretreatment processes. Recombinant Zymomonas mobilis 8b, a recently developed integrant of Zymomonas mobilis 31821(pZB5), tolerated acetic acid up to 16 g l(-1) and achieved 82%-87% (w/w) ethanol yields from pure glucose/xylose solutions at pH 6 and temperatures of 30 degrees C and 37 degrees C. An ethanol yield of 85% (w/w) was achieved on glucose/xylose from hydrolysate produced by dilute sulfuric acid pretreatment of corn stover after an overliming' process was used to improve hydrolysate fermentability. PMID:15055769

Mohagheghi, Ali; Dowe, Nancy; Schell, Daniel; Chou, Yat-Chen; Eddy, Christina; Zhang, Min

2004-02-01

 
 
 
 
81

Ethanol from lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

Lignocellulosic biomass includes agricultural and forestry residues, municipal solid waste (MSW), fiber resulting from grain operations, waste cellulosics (e.g. paper and pulp operations), and energy crops. Taken together, these materials represent one of the most abundant renewable resources on earth. The conversion of even a small portion of this resource to ethanol could substantially reduce current gasoline consumption and dependence on petroleum. Lignocellulosic materials are composed of three major components: cellulose, hemicellulose, and lignin. The cellulose and hemicellulose polymers can be hydrolyzed into their component sugars, primarily glucose and xylose, respectively, which can then be fermented to ethanol. Ethanol and fuel additives from ethanol have properties useful for dealing with urban air pollution. In addition, using renewable lignocellulosic resources for ethanol production can reduce the accumulation of carbon dioxide in the atmosphere and thereby aid in the prevention of global warming. Moreover, producing ethanol from an abundant domestic lignocellulosic resource will provide new opportunities for agriculture. In an overall process for converting lignocellulosic biomass to ethanol, the biomass is first pretreated by mechanical and chemical processes. An acid-based pretreatment process is one method that can be used to hydrolyze the hemicellulose to xylose. To hydrolyze the cellulose to glucose, processes based on the use of acids or cellulase enzyme can then be used. For enzymatic processes, the rate and yield of glucose from cellulose depends on the characteristics of the cellulose enzymes, which are synthesized by cellulolytic microorganisms such as fungi or bacteria. A variety of microorganisms can be used to ferment xylose and glucose to ethanol. 178 refs., 3 figs., 14 tabs.

Schell, D.J.; McMillian, J.D.; Philippidis, G.P. [and others

1992-12-31

82

Effect of lignocellulose-derived inhibitors on growth and hydrogen production by Thermoanaerobacterium thermosaccharolyticum W16  

Energy Technology Data Exchange (ETDEWEB)

In the process of producing H{sub 2} from lignocellulosic materials, inhibitory compounds could be potentially formed during pre-treatment. This work experimentally investigated the effect of lignocellulose-derived inhibitors on growth and hydrogen production by Thermoanaerobacterium thermosaccharolyticum W16. Representative compounds presented in corn stover acid hydrolysate were added in various concentrations, individually or in various combinations and subsequently inhibitions on growth and H{sub 2} production were quantified. Acetate sodium was not inhibitory to T. thermosaccharolyticum W16, rather than it was stimulatory to the growth and H{sub 2} production. Alternatively, furfural, hydroxymethylfurfural (HMF), vanillin and syringaldehyde were potent inhibitors of growth and hydrogen production even though these compounds showed inhibitory effect depending on their concentrations. Synergistic inhibitory effects were exhibited in the introduction of combinations of inhibitors to the medium and in hydrolysate with concentrated inhibitors. Fermentation results from hydrolysates revealed that to increase the efficiency of this bioprocess from corn stover hydrolysate, the inhibitory compounds concentration must be reduced to the levels present in the raw hydrolysate. (author)

Cao, Guang-Li; Ren, Nan-Qi; Wang, Ai-Jie; Guo, Wan-Qian; Xu, Ji-Fei; Liu, Bing-Feng [State Key Lab of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090 (China)

2010-12-15

83

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

UK PubMed Central (United Kingdom)

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.

Ye L; Hudari MS; Zhou X; Zhang D; Li Z; Wu JC

2013-06-01

84

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

2013-03-16

85

Utilization of lignocellulosic polysaccharides  

Science.gov (United States)

Lignocellulosic biomass represents a vast supply of fermentable carbohydrates and functional aromatic compounds. Conversion of lignocellulosics to ethanol and other useful products would be of widespread economical and environmental benefit. Better understanding of the behavior of different lignocellulosic feedstocks in fermentation protocols as well as catalytic activities involved in lignocellulosic depolymerization will further enhance the commercial viability of biomass-to-ethanol conversion processes. The relative toxicity of the combined non-xylose components in prehydrolysates derived from three different lignocellulosic biomass feedstocks (poplar, corn stover and switchgrass, or Panicum virgatum L.) was determined using a Pichia stipits fermentation assay. The relative toxicity of the prehydrolysates, in decreasing order, was poplar-derived prehydrolysates > switchgrass-derived prehydrolysates > corn stover-derived prehydrolysates. Ethanol yields averaged 74%, 83% and 88% of control values for poplar, switchgrass and corn stover prehydrolysates, respectively. Volumetric ethanol productivities (g ethanol lsp{-1} hsp{-1}) averaged 32%, 70% and 102% of control values for poplar, switchgrass and corn stover prehydrolysates, respectively. Ethanol productivities correlated closely with acetate concentrations in the prehydrolysates; however, regression lines correlating acetate concentrations and ethanol productivities were found to be feedstock-dependent. Differences in the relative toxicity of xylose-rich prehydrolysates derived from woody and herbaceous feedstocks are likely due to the relative abundance of a variety of inhibitory compounds, e.g. acetate and aromatic compounds. Fourteen aromatic monomers present in prehydrolysates prepared from corn stover, switchgrass, and poplar were tentatively identified by comparison with published mass spectra. The concentrations of the aromatic monomers totaled 112, 141 and 247 mg(l)sp{-1} for corn stover, switchgrass and poplar prehydrolysates, respectively. The woody and herbaceous feedstocks differed in both amount and type of aromatic monomers. The cellulases of Trichoderma reesei are the most widely studied for use in the depolymerization of lignocellulosics. The Trichoderma cellobiohydrolases CBH1 and CBH2 are traditionally categorized as exo-acting cellulases. A simple individual-based model was created to explore the potential effects of native endo activity on substrate-velocity profiles. The model results indicate that an enzyme with a small amount of endo activity will show an apparent substrate inhibition as substrate levels are increased. Actual hydrolysis studies using affinity chromatography-purified CBH2 preparations from three laboratories indicate that CBH2 has native endo activity, while CBH1 does not.

Fenske, John James

86

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

Energy Technology Data Exchange (ETDEWEB)

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

Ingram, Lonnie O. (Gainesville, FL)

2000-01-01

87

Chemical processing of lignocellulosics  

Energy Technology Data Exchange (ETDEWEB)

Lignocellulosics can be separated into their three main components by extraction with acetic acid, containing 0.1% hydrogen chloride, at 110/sup 0/C. The residual pulp can be bleached in the same solvent with peracetic acid, which is formed in situ when adding hydrogen peroxide. Hemicelluloses and lignin are obtained in a low condensed and relatively reactive form that may be converted into valuable chemical raw materials. Some aspects of such conversions are discussed.

Nimz, H.H.; Casten, R.

1986-06-01

88

Protein hydrolysates in sports nutrition  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract It has been suggested that protein hydrolysates providing mainly di- and tripeptides are superior to intact (whole) proteins and free amino acids in terms of skeletal muscle protein anabolism. This review provides a critical examination of protein hydrolysate studies conducted in healthy humans with special reference to sports nutrition. The effects of protein hydrolysate ingestion on blood amino acid levels, muscle protein anabolism, body composition, exercise performance and muscle glycogen resynthesis are discussed.

Manninen Anssi H

2009-01-01

89

Fungal delignification of lignocellulosic biomass improves the saccharification of cellulosics.  

Science.gov (United States)

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

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

2010-08-14

90

Fungal delignification of lignocellulosic biomass improves the saccharification of cellulosics.  

UK PubMed Central (United Kingdom)

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

Gupta R; Mehta G; Khasa YP; Kuhad RC

2011-07-01

91

Succinic Acid Production from Corn Cob Hydrolysates by Genetically Engineered Corynebacterium glutamicum.  

UK PubMed Central (United Kingdom)

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.

Wang C; Zhang H; Cai H; Zhou Z; Chen Y; Chen Y; Ouyang P

2013-10-01

92

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

Scientific Electronic Library Online (English)

Full Text Available 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 lignocellulosic 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 s (more) train 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.

Betancur, Gabriel J. Vargas; Pereira Jr, Nei

2010-09-01

93

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 archi...

Malherbe, Stephanus; Cloete, T.E. (Thomas Eugene), 1958-

94

Protein hydrolysates in sports nutrition  

Digital Repository Infrastructure Vision for European Research (DRIVER)

It has been suggested that protein hydrolysates providing mainly di- and tripeptides are superior to intact (whole) proteins and free amino acids in terms of skeletal muscle protein anabolism. This review provides a critical examination of protein hydrolysate studies conducted in healthy humans with...

Manninen, Anssi H

95

Co-hydrolysis of lignocellulosic biomass for microbial lipid accumulation.  

UK PubMed Central (United Kingdom)

The herbaceous perennial energy crops miscanthus, giant reed, and switchgrass, along with the annual crop residue corn stover, were evaluated for their bioconversion potential. A co-hydrolysis process, which applied dilute acid pretreatment, directly followed by enzymatic saccharification without detoxification and liquid-solid separation between these two steps was implemented to convert lignocellulose into monomeric sugars (glucose and xylose). A factorial experiment in a randomized block design was employed to optimize the co-hydrolysis process. Under the optimal reaction conditions, corn stover exhibited the greatest total sugar yield (glucose?+?xylose) at 0.545 g g(-1) dry biomass at 83.3% of the theoretical yield, followed by switch grass (0.44 g g(-1) dry biomass, 65.8% of theoretical yield), giant reed (0.355 g g(-1) dry biomass, 64.7% of theoretical yield), and miscanthus (0.349 g g(-1) dry biomass, 58.1% of theoretical yield). The influence of combined severity factor on the susceptibility of pretreated substrates to enzymatic hydrolysis was clearly discernible, showing that co-hydrolysis is a technically feasible approach to release sugars from lignocellulosic biomass. The oleaginous fungus Mortierella isabellina was selected and applied to the co-hydrolysate mediums to accumulate fungal lipids due to its capability of utilizing both C5 and C6 sugars. Fungal cultivations grown on the co-hydrolysates exhibited comparable cell mass and lipid production to the synthetic medium with pure glucose and xylose. These results elucidated that combining fungal fermentation and co-hydrolysis to accumulate lipids could have the potential to enhance the utilization efficiency of lignocellulosic biomass for advanced biofuels production.

Ruan Z; Zanotti M; Zhong Y; Liao W; Ducey C; Liu Y

2013-04-01

96

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

97

METHOD OF HYDROLYSATE PRODUCTION  

UK PubMed Central (United Kingdom)

FIELD: food products. ^ SUBSTANCE: fish raw materials are cut, washed and rinsed by anolyte of electrochemically activated water, milled. Reaction mixture is made by mixing fish raw materials with water and enzyme preparation. Enzymatic splitting of reaction mixture is done. Inactivation of enzyme system by heating up the reaction mixture is performed, partition of reaction mixture is done with extraction of hydrolysate, its de-fatting in the separator and drying. The process of enzymatic splitting is performed, using catholyte in quantity 30% materials weight at the temperature 55C. To obtain hydrolizate without separation of non-enzymated protein residue, enzymatic splitting is performed 1.5-2 hours before reaching hydrolysis depth with 25-27% filtrate nitrogen of total quantity of materials nitrogen. In order to make hydrolysate with separation of non-enzymated protein residue enzymatic splitting is performed 4-6 hours before reaching hydrolysis depth with 60-65% filtrate nitrogen of total quantity of materials nitrogen. ^ EFFECT: reagentless creation of media pH, decrease of duration of operating practices of processing, acquisition of final product with low leach content, improvement of hygiene at the place of production. ^ 3 cl, 2 ex

RAZUMOVSKAJA RAMZIJA GUMEROVNA; KIL MAEV ALEKSEJ ALEKSEEVICH

98

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

UK PubMed Central (United Kingdom)

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

Goshima T; Tsuji M; Inoue H; Yano S; Hoshino T; Matsushika A

2013-01-01

99

Ethanol from lignocellulosic biomass  

Scientific Electronic Library Online (English)

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

Abril, Diana; Abril, Alejandro

2009-08-01

100

Preparation of Fish Protein Hydrolysates.  

Science.gov (United States)

An innovative procedure for developing and building a laboratory digestion unit capable of handling and producing approximately 10 liters of fish protein hydrolysate (FPH) is described. The unit consists of a pump, heat exchanger, and holding vat. Comminu...

D. L. Crawford

1973-01-01

 
 
 
 
101

Biological Systems for Lignocellulose Conversion.  

Science.gov (United States)

Microbiological approaches to the utilization of lignocellulosic biomass are reported. The two biological systems examined were Phanaerochate chrysosporium and Clostridium thermocellum. Detailed studies of lignin metabolism by P. chrysosporium and of cell...

J. G. Zeikus T. K. Kirk

1980-01-01

102

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

103

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

104

Pervaporation behavior and integrated process for concentrating lignocellulosic ethanol through polydimethylsiloxane (PDMS) membrane.  

UK PubMed Central (United Kingdom)

The effects of by-products from ethanol fermentation and hydrolysates of lignocelluloses on ethanol diffusion through polydimethylsiloxane (PDMS) membranes with/without silicalite-1 were investigated. A pervaporation process was integrated with lignocellulosic fermentation to concentrate bioethanol using bare PDMS membranes. Results showed that yeasts, solid particles, and salts increased ethanol flux and selectivity through the membranes (PDMS with/without silicalite-1), whereas glucose exerted negative effects on the performance. On bare PDMS membrane, the performance was not obviously affected by the existence of aliphatic acids. However, on PDMS-silicalite-1 membrane, a remarkable decrease in ethanol selectivity and a rapid growth of total flux in the presence of aliphatic acids were observed. These phenomena were due to the interaction of acids with silanol (Si-OH) groups to break the dense membrane surface. On the PDMS membranes with/without silicalite-1, degradation products of lignocellulosic hydrolysates such as furfural and hydroxyacetone slightly influenced separation performance. These results revealed that an integrated process can effectively eliminate product inhibition, improve ethanol productivity, and enhance the glucose conversion rate.

Chen J; Zhang H; Wei P; Zhang L; Huang H

2013-06-01

105

Pervaporation behavior and integrated process for concentrating lignocellulosic ethanol through polydimethylsiloxane (PDMS) membrane.  

Science.gov (United States)

The effects of by-products from ethanol fermentation and hydrolysates of lignocelluloses on ethanol diffusion through polydimethylsiloxane (PDMS) membranes with/without silicalite-1 were investigated. A pervaporation process was integrated with lignocellulosic fermentation to concentrate bioethanol using bare PDMS membranes. Results showed that yeasts, solid particles, and salts increased ethanol flux and selectivity through the membranes (PDMS with/without silicalite-1), whereas glucose exerted negative effects on the performance. On bare PDMS membrane, the performance was not obviously affected by the existence of aliphatic acids. However, on PDMS-silicalite-1 membrane, a remarkable decrease in ethanol selectivity and a rapid growth of total flux in the presence of aliphatic acids were observed. These phenomena were due to the interaction of acids with silanol (Si-OH) groups to break the dense membrane surface. On the PDMS membranes with/without silicalite-1, degradation products of lignocellulosic hydrolysates such as furfural and hydroxyacetone slightly influenced separation performance. These results revealed that an integrated process can effectively eliminate product inhibition, improve ethanol productivity, and enhance the glucose conversion rate. PMID:23732286

Chen, Jingwen; Zhang, Hongman; Wei, Ping; Zhang, Lin; Huang, He

2013-06-01

106

Bioethanol from lignocellulosic biomass.  

UK PubMed Central (United Kingdom)

China is suffering from a sustained shortage of crude oil supply, making fuel ethanol and other biofuels alternative solutions for this issue. However, taking into account the country's large population and dwindling arable land due to rapid urbanization, it is apparent that current fuel ethanol production from grain-based feedstocks is not sustainable, and lignocellulosic biomass, particularly agricultural residues that are abundantly available in China, is the only choice for China to further expand its fuel ethanol production, provided economically viable processes can be developed. In this chapter, cutting edge progress in bioethanol is reviewed, with a focus on the understanding of the molecular structure of the feedstock, leading pretreatment technologies, enzymatic hydrolysis of the cellulose component and strategies for the co-fermentation of the C5 and C6 sugars with engineered microorganisms. Finally, process integration and optimization is addressed with a case study on the COFCO Corporation's pilot plant, and challenges and perspectives for commercial production of bioethanol are highlighted.

Zhao XQ; Zi LH; Bai FW; Lin HL; Hao XM; Yue GJ; Ho NW

2012-01-01

107

Thermophilic lignocellulose deconstruction.  

UK PubMed Central (United Kingdom)

Thermophilic microorganisms are attractive candidates for conversion of lignocellulose to biofuels since 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 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., multi-enzyme complexes) and non-cellulosomal (i.e., "free" enzyme systems). Plant biomass deconstructing thermophilic bacteria from the genera Clostridium (cellulosomal) and Caldicellulosiruptor (non-cellulosomal), which have potential as metabolic engineering platforms for producing biofuels, are compared and contrasted from a systems biology perspective. This article is protected by copyright. All rights reserved.

Blumer-Schuette SE; Brown SD; Sander KB; Bayer EA; Kataeva I; Zurawski JV; Conway JM; Adams MW; Kelly RM

2013-10-01

108

Conversion of Lignocellulose by Actinomycete Microorganisms, 1978.  

Science.gov (United States)

Specific research objectives include: the isolation of a large number of lignocellulose decomposing thermophilic actinomycetes; the characterization of the ability of each isolate to attack lignin and cellulose within the lignocellulose complex; and the o...

D. L. Crawford

1978-01-01

109

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

UK PubMed Central (United Kingdom)

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.

Yu X; Zheng Y; Dorgan KM; Chen S

2011-05-01

110

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

2011-04-03

111

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

112

Lignosulfonate and elevated pH can enhance enzymatic saccharification of lignocelluloses.  

UK PubMed Central (United Kingdom)

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

Wang Z; Lan T; Zhu J

2013-01-01

113

Lignosulfonate and elevated pH can enhance enzymatic saccharification of lignocelluloses  

Directory of Open Access Journals (Sweden)

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

Wang ZJ; Lan TQ; Zhu JY

2013-01-01

114

New process to degrade lignocellulose  

International Nuclear Information System (INIS)

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

1982-01-01

115

Planting and cultivating annual lignocelluloses  

Energy Technology Data Exchange (ETDEWEB)

Crop yields for 1982 indicate that topinambur, sunflower and sorghum could be of economic interest as suppliers of biomass provided that, along with the lignocellulose mass, the tuber and seed yields are also utilized, and that for sorghum the sugar instead of the lignin is used or at least part of the plants are used as fodder. The production processes described here could pose interesting production alternatives for today's agriculture of yields/ha continue to increase and lignocellulose utilization is improved (=higher prices).

Kahnt, G.; Leible, L.

1983-01-01

116

Biohydrogen production from lignocellulosic feedstock.  

UK PubMed Central (United Kingdom)

Due to the recent energy crisis and rising concern over climate change, the development of clean alternative energy sources is of significant interest. Biohydrogen produced from cellulosic feedstock, such as second generation feedstock (lignocellulosic biomass) and third generation feedstock (carbohydrate-rich microalgae), is a promising candidate as a clean, CO2-neutral, non-polluting and high efficiency energy carrier to meet the future needs. This article reviews state-of-the-art technology on lignocellulosic biohydrogen production in terms of feedstock pretreatment, saccharification strategy, and fermentation technology. Future developments of integrated biohydrogen processes leading to efficient waste reduction, low CO2 emission and high overall hydrogen yield is discussed.

Cheng CL; Lo YC; Lee KS; Lee DJ; Lin CY; Chang JS

2011-09-01

117

Production of bioethanol : Structural characterization of pretreated lignocellulose  

DEFF Research Database (Denmark)

Efficient conversion of lignocellulosic materials to ethanol requires pretreatment and hydrolysis prior to the ethanolic fermentation. This pretreatment renders the biomass more susceptible to the subsequent hydrolysis. Of the wide variety of pretreatment methods presently available, wet oxidation (Bjerre et al., 1996; McGinnis et al., 1983; Schmidt & thomsen, 1997) and steam explosion (puls et al., 1985; Saddler et al., 1993) are among the most promising. However, fermentation of the pretreated hydrolysates with the anaerobic thermophilic bacterium Thermoanaerobacter mathranii strain A3M1, adapted to the hemicellulose hydrolysate, has until now resulted in low ethanol yields, indicating incomplete hydrolyzation or the presence of inhibitory compounds in the hydrolyzate (Ahring et al., 1996; Sommer, 1998). Therefore, a structural study of the hemicellulosefraction is being conducted. This includes investigations of the structure of the hemicellulose fraction prior to pretreatment, prior to hydrolysis, prior to fermentation, and after fermentation. Various techniques, such as gas chromatography / mass spectrometry (GC/MS), size-exclusion chromatography (SEC), and nuclear magnetic resonance spectrometry (NMR), will be used in this study. Preliminary results from these investigations will be presented and discussed.

Tranekjær, Michael; Sommer, Peter

1998-01-01

118

Lignocellulose biotechnology: Current and future prospects  

Energy Technology Data Exchange (ETDEWEB)

Lignocellulose is the most abundant biomass available on Earth. It has attracted considerable attention as an alternate feed stock and energy resource because of the large quantities available and its renewable nature. The potential uses of lignocelluloses are in pulp and paper industries, production of fuel alcohol and chemicals, protein for food, and feed using biotechnological means. The current industrial activity of lignocellulosic biomass fermentation is limited mainly because of the difficulty in economic bioconversion of these materials to value-added products. Considerable improvement in many processes related to lignocellulose biotechnology appeared during the last decade. Current uses of lignocellulosic biomass, process constraints, and areas of future research are discussed here.

Kuhad, R.C. (Univ. of Delhi South Campus, New Delhi (India). Dept. of Microbiology); Singh, A. (Biochemical Engineering Research Centre, New Delhi (India))

1993-07-01

119

[Progress in lignocellulose deconstruction by fungi].  

UK PubMed Central (United Kingdom)

Inefficient degradation of lignocellulose is one of the main barriers for the utilization of renewable plant biomass for biofuel production. The bottleneck of the biorefinery process is the generation of fermentable sugars from complicated biomass polymers. In nature, the main microbes of lignocelluloses deconstruction are fungi. Therefore, elucidating the mechanism of lignocelluloses degradation by fungi is of critical importance for the commercialization of lignocellulosic biofuels. This review focuses on the progress in lignocelluloses degradation pathways in fungi, especially on the advances made by functional genomics studies.

Tian C; Ma Y

2010-10-01

120

[Progress in lignocellulose deconstruction by fungi].  

Science.gov (United States)

Inefficient degradation of lignocellulose is one of the main barriers for the utilization of renewable plant biomass for biofuel production. The bottleneck of the biorefinery process is the generation of fermentable sugars from complicated biomass polymers. In nature, the main microbes of lignocelluloses deconstruction are fungi. Therefore, elucidating the mechanism of lignocelluloses degradation by fungi is of critical importance for the commercialization of lignocellulosic biofuels. This review focuses on the progress in lignocelluloses degradation pathways in fungi, especially on the advances made by functional genomics studies. PMID:21218619

Tian, Chaoguang; Ma, Yanhe

2010-10-01

 
 
 
 
121

Bioethanol production from the hydrolysate of rape stem in a surface-aerated fermentor.  

UK PubMed Central (United Kingdom)

In this study, we investigated the feasibility of producing bioethanol from the hydrolysate of rape stem. Specifically, the most ideal yeast strain was screened, and the microaeration was performed by surface aeration on a liquid medium surface. Among the yeast strains examined, Pichia stipitis CBS 7126 displayed the best performance in bioethanol production during the surface-aerated fermentor culture. Pichia stipitis CBS 7126 produced maximally 9.56 g/l of bioethanol from the initial total reducing sugars (about 28 g/l). The bioethanol yield was 0.397 (by the DNS method). Furthermore, this controlled surface aeration method holds promise for use in the bioethanol production from the xylose-containing lignocellulosic hydrolysate of biomass.

Yeon JH; Lee SE; Choi WY; Choi WS; Kim IC; Lee HY; Jung KH

2011-01-01

122

Treatment of rice straw hemicellulosic hydrolysates with advanced oxidative processes: a new and promising detoxification method to improve the bioconversion process.  

UK PubMed Central (United Kingdom)

BACKGROUND: The use of lignocellulosic constituents in biotechnological processes requires a selective separation of the main fractions (cellulose, hemicellulose and lignin). During diluted acid hydrolysis for hemicellulose extraction, several toxic compounds are formed by the degradation of sugars and lignin, which have ability to inhibit microbial metabolism. Thus, the use of a detoxification step represents an important aspect to be considered for the improvement of fermentation processes from hydrolysates. In this paper, we evaluated the application of Advanced Oxidative Processes (AOPs) for the detoxification of rice straw hemicellulosic hydrolysate with the goal of improving ethanol bioproduction by Pichia stipitis yeast. Aiming to reduce the toxicity of the hemicellulosic hydrolysate, different treatment conditions were analyzed. The treatments were carried out according to a Taguchi L16 orthogonal array to evaluate the influence of Fe+2, H2O2, UV, O3 and pH on the concentration of aromatic compounds and the fermentative process. RESULTS: The results showed that the AOPs were able to remove aromatic compounds (furan and phenolic compounds derived from lignin) without affecting the sugar concentration in the hydrolysate. Ozonation in alkaline medium (pH 8) in the presence of H2O2 (treatment A3) or UV radiation (treatment A5) were the most effective for hydrolysate detoxification and had a positive effect on increasing the yeast fermentability of rice straw hemicellulose hydrolysate. Under these conditions, the higher removal of total phenols (above 40%), low molecular weight phenolic compounds (above 95%) and furans (above 52%) were observed. In addition, the ethanol volumetric productivity by P. stipitis was increased in approximately twice in relation the untreated hydrolysate. CONCLUSION: These results demonstrate that AOPs are a promising methods to reduce toxicity and improve the fermentability of lignocellulosic hydrolysates.

Silva JP; Carneiro LM; Roberto IC

2013-01-01

123

FED BATCH PROCESS FOR BIOCHEMICAL CONVERSION OF LIGNOCELLULOSIC BIOMASS TO ETHANOL  

UK PubMed Central (United Kingdom)

A method for optimization of a fed-batch lignocellulosic biomass hydrolysis process wherein the hydrolysis time is minimized by controlling the feed addition volume and / or batch addition frequency of prehydrolysed lignocellulosic feed and optionally the enzyme feed. The increase over time in hydrolysate consistency and volume and / or concentration of sugars released in the reactor, so that the enzymatic hydrolysis is controlled, significantly reduces the impact of cellulase feedback inhibition, especially for enzyme contents lower than 0.5%. The overall time to reach conversion of the total prehydrolysate feed is reduced significantly where the batch addition frequency is equal to one batch each time 70% to 90% of a theoretical cellulose to glucose conversion is reached, preferably when 80% conversion is reached. At an enzyme load of 0.3% in the reaction mixture, the optimum frequency each time 80% conversion was reached was found to be one batch every 105 minutes.

BENSON ROBERT ASHLEY COOPER; BENECH REGIS-OLIVIER

124

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

Directory of Open Access Journals (Sweden)

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

Mohammad J. Taherzadeh; Keikhosro Karimi

2008-01-01

125

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

126

Transcriptional profiling of Saccharomyces cerevisiae T2 cells upon exposure to hardwood spent sulphite liquor: comparison to acetic acid, furfural and hydroxymethylfurfural.  

Science.gov (United States)

Global gene expression was analyzed in Saccharomyces cerevisiae T2 cells grown in the presence of hardwood spent sulphite liquor (HW SSL) and each of the three main inhibitors in HW SSL, acetic acid, hydroxymethyfurfural (HMF) and furfural, using a S. cerevisiae DNA oligonucleotide microarray. The objective was to compare the gene expression profiles of T2 cells in response to the individual inhibitors against that elicited in response to HW SSL. Acetic acid mainly affected the expression of genes related to the uptake systems of the yeast as well as energy generation and metabolism. Furfural and HMF mainly affected the transcription of genes involved in the redox balance of the cell. On the other hand, the effect of HW SSL on S. cerevisiae T2 cells was distinct and considerably more diverse as compared to the effect of individual inhibitors found in lignocellulosic hydrolysates. This is not surprising as HW SSL contains a complex mixture of inhibitors which may act synergistically. HW SSL elicited significant changes in expression of genes involved in diverse and multiple effects on several aspects of the cellular structure and function. A notable response to HW SSL was decreased expression of the ribosomal protein genes in T2 cells. In addition, HW SSL decreased the expression of genes functioning in the synthesis and transport of proteins as well as metabolism of carbohydrates, lipids, vitamins and vacuolar proteins. Furthermore, the expression of genes involved in multidrug resistance, iron transport and pheromone response was increased, suggesting that T2 cells grown in the presence of HW SSL may have activated pheromone response and/or activated pleiotropic drug response. Some of the largest changes in gene expression were observed in the presence of HW SSL and the affected genes are involved in mating, iron transport, stress response and phospholipid metabolism. A total of 59 out of the 400 genes differentially expressed in the presence of HW SSL, acetic acid, HMF and furfural, belonged to the category of poorly characterized genes. The results indicate that transcriptional responses to individual lignocellulosic inhibitors gave a different picture and may not be representative of how the cells would respond to the presence of all the inhibitors in lignocellulosic hydrolysates such as HW SSL. PMID:23539198

Bajwa, Paramjit K; Ho, Chi-Yip; Chan, Chi-Kin; Martin, Vincent J J; Trevors, Jack T; Lee, Hung

2013-03-29

127

Transcriptional profiling of Saccharomyces cerevisiae T2 cells upon exposure to hardwood spent sulphite liquor: comparison to acetic acid, furfural and hydroxymethylfurfural.  

UK PubMed Central (United Kingdom)

Global gene expression was analyzed in Saccharomyces cerevisiae T2 cells grown in the presence of hardwood spent sulphite liquor (HW SSL) and each of the three main inhibitors in HW SSL, acetic acid, hydroxymethyfurfural (HMF) and furfural, using a S. cerevisiae DNA oligonucleotide microarray. The objective was to compare the gene expression profiles of T2 cells in response to the individual inhibitors against that elicited in response to HW SSL. Acetic acid mainly affected the expression of genes related to the uptake systems of the yeast as well as energy generation and metabolism. Furfural and HMF mainly affected the transcription of genes involved in the redox balance of the cell. On the other hand, the effect of HW SSL on S. cerevisiae T2 cells was distinct and considerably more diverse as compared to the effect of individual inhibitors found in lignocellulosic hydrolysates. This is not surprising as HW SSL contains a complex mixture of inhibitors which may act synergistically. HW SSL elicited significant changes in expression of genes involved in diverse and multiple effects on several aspects of the cellular structure and function. A notable response to HW SSL was decreased expression of the ribosomal protein genes in T2 cells. In addition, HW SSL decreased the expression of genes functioning in the synthesis and transport of proteins as well as metabolism of carbohydrates, lipids, vitamins and vacuolar proteins. Furthermore, the expression of genes involved in multidrug resistance, iron transport and pheromone response was increased, suggesting that T2 cells grown in the presence of HW SSL may have activated pheromone response and/or activated pleiotropic drug response. Some of the largest changes in gene expression were observed in the presence of HW SSL and the affected genes are involved in mating, iron transport, stress response and phospholipid metabolism. A total of 59 out of the 400 genes differentially expressed in the presence of HW SSL, acetic acid, HMF and furfural, belonged to the category of poorly characterized genes. The results indicate that transcriptional responses to individual lignocellulosic inhibitors gave a different picture and may not be representative of how the cells would respond to the presence of all the inhibitors in lignocellulosic hydrolysates such as HW SSL.

Bajwa PK; Ho CY; Chan CK; Martin VJ; Trevors JT; Lee H

2013-06-01

128

USE OF STILLAGE RESIDUE AS A NUTRIENT SOURCE FOR FERMENTATION OF HYDROLYZED LIGNOCELLULOSIC BIOMASS TO ETHANOL  

UK PubMed Central (United Kingdom)

A process for the production of ethanol wherein a hydrolyzed lignocellulosic biomass is fermented in the presence of a stillage residue. The fermentation of cellulosic hydrolysates is improved by adding prior to and/or during fermentation a stillage residue side stream from a corn starch-to-ethanol process as a nutrient source for the yeast organisms used in the fermentation. Stillage residues from the grain dry mill ethanol producing process, including the whole stillage, wet cake, thin stillage, and/or syrup are added to assist as a nitrogen and nutrient source for the fermentive processes. The stillage residue is produced by any grain-to- ethanol process.

BENSON ROBERT ASHLEY COOPER; BENECH REGIS-OLIVIER

129

Ethanol fermentation by Pichia stipitis of combined pentose and hexose sugars from lignocellulosics prehydrolysed by SO/sub 2/ and enzymatically saccharified  

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Lignocellulosic biomass, namely pine, aspen, and corn stover, were prehydrolysed using SO/sub 2/ as the hydrolysing catalyst. The prehydrolysis residues were directly saccharified, without washing, by cellulolytic enzymes, whereby about 90% of theoretical yields of sugars were obtained. Fermentation of the hydrolysates containing both the hemicellulose and cellulose sugars by a pentose fermenting yeast, Pichia stipitis R, gave yields of 372, 346, and 388 litres of ethanol per tonne (dry weight) from pine, aspen and corn stover respectively. The technical aspects of the SO/sub 2/ catalysed prehydrolysis and enzymatic saccharification stages and the advantages of fermentation by pentose fermenting yeasts are discussed.

Wayman, M.; Seagrave, C.; Parekh, S.R.

1987-04-01

130

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

Energy Technology Data Exchange (ETDEWEB)

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. 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 75C. Both microorganisms simultaneously and completely utilized all pentoses, hexoses and oligomeric saccharides up to a total concentration of 17 g l{sup -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 H{sub 2} 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{sup -1}, sugar consumption was incomplete, and lower hydrogen yields of 2.0 to 2.4 mol per mol of consumed hexose were obtained. 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, G.J.; Bakker, R.R.; Budde, M.A.W.; Lai, M.H.; Mars, A.E.; Claassen, P.A.M. [Agrotechnology and Food Sciences Group, Wageningen University and Research Centre, PO Box 17, 6700 AA Wageningen (Netherlands)

2009-06-17

131

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

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

de Vrije Truus; Bakker Robert R; Budde Miriam AW; Lai Man H; Mars Astrid E; Claassen Pieternel AM

2009-01-01

132

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

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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

133

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; Minu K Ashok; Aditi Banerjee; Kishore V. V. N.

2010-01-01

134

Hydrothermal carbonization of lignocellulosic biomass.  

UK PubMed Central (United Kingdom)

Hydrothermal carbonization (HTC) is a novel thermochemical conversion process to convert lignocellulosic biomass into value-added products. HTC processes were studied using two different biomass feedstocks: corn stalk and Tamarix ramosissima. The treatment brought an increase of the higher heating values up to 29.2 and 28.4 MJ/kg for corn stalk and T. ramosissima, respectively, corresponding to an increase of 66.8% and 58.3% as compared to those for the raw materials. The resulting lignite-like solid products contained mainly lignin with a high degree of aromatization and a large amount of oxygen-containing groups. Liquid products extracted with ethyl acetate were analyzed by gas chromatography-mass spectrometry. The identified degradation products were phenolic compounds and furan derivatives, which may be desirable feedstocks for biodiesel and chemical production. Based on these results, HTC is considered to be a potential treatment in a lignocellulosic biomass refinery.

Xiao LP; Shi ZJ; Xu F; Sun RC

2012-08-01

135

Degradation of ligno-cellulose biomass  

Energy Technology Data Exchange (ETDEWEB)

The use of lignocellulose to produce chemicals like furfural, ethyl alcohol, crude and refined sugars, acetone, butanol, levulinic acid, oxalic acid, hydrocarbon fuel, lignocellulose plastics etc. require operations like hydrolysis, oxidation, fermentations, pyrolysis and reduction. As a matter of fact every known chemical could conceivably be made from wood. The crux of the situation is economics. Degradation of lignocellulose could be broadly effected by (I) Pyrolysis, (II) Hydrolysis, (III) Biodegradation, (IV) Radiolysis by gamma rays.

Chawla, J.S.

1985-10-01

136

Treating lignocellulosic materials by pyrolysis  

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High-quality charcoal is prepared by heating lignocellulosic materials in organic liquids, preferably obtained by pyrolysis of ligneous materials, at 400-450/sup 0/ and pressures near atmosphere. Thus, 1 ton sawdust (moisture content 20%) in 2 tons organic liquid is heated gradually to 450/sup 0/, giving 270 g charcoal containing 85% fixed C, and a pyroligneous distillate containing 2100 kg organic phase, 480 kg aqueous phase, and 200 kg combustible gas.

Schwob, Y.

1981-09-23

137

MICROBIAL TREATMENT OF LIGNOCELLULOSIC BIOMASS  

UK PubMed Central (United Kingdom)

Aspects of the present invention relate to methods of microbially treating lignocellulosic biomass using cellulose- and/or hemicellulose-degrading bacteria. In certain embodiments, the microbially treated material is then subjected to thermal and/or chemical pretreatment. In tandem with the microbial treatment the thermal and/or chemical pretreatment may result in the production of fewer degradation products, thereby allowing for higher overall yields of ethanol per ton of starting biomass.

ALL SARAH; HOGSETT DAVID A

138

Microbial Treatment of Lignocellulosic Biomass  

UK PubMed Central (United Kingdom)

Aspects of the present invention relate to methods of microbially treating lignocellulosic biomass using cellulose- and/or hemicellulose-degrading bacteria. In certain embodiments, the microbially treated material is then subjected to thermal and/or chemical pretreatment. In tandem with the microbial treatment the thermal and/or chemical pretreatment may result in the production of fewer degradation products, thereby allowing for higher overall yields of ethanol per ton of starting biomass.

ALL SARAH; HOGSETT DAVID ANTHONY

139

Quantification of glucose, xylose, arabinose, furfural, and HMF in corncob hydrolysate by HPLC-PDA-ELSD.  

UK PubMed Central (United Kingdom)

Lignocellulose and other carbohydrates are being studied extensively as potential renewable carbon sources for liquid biofuels and other valuable chemicals. In the present study, a simple, sensitive, selective, and reliable HPLC method using a photodiode array (PDA) detector and an evaporative light scattering detector (ELSD) was developed for the simultaneous determination of important sugars (D(+)-cellobiose, glucose, xylose, and arabinose), furfural and 5-hydroxymethylfurfural (5-HMF) in lignocellulose hydrolysate. The analysis was carried out on an Aminex HPX-87H column (250 mm × 4.6 mm, 5 ?m particle size). Ultra-pure water with 0.00035 M H(2)SO(4) was used as the mobile phase with a flow rate of 0.6 mL/min. The temperature of the ELSD drift tube was kept at 50 °C, the carrier gas pressure was 350 kPa, and the gain was set at 7. Furfural and 5-HMF were quantified on a PDA detector at 275 nm and 284 nm, respectively. The sugar concentrations were determined by ELSD. This method was validated for accuracy and precision. The regression equation revealed a good linear relationship (r(2) = 0.9986 ± 0.0012) within the test ranges. The method showed good reproducibility for the quantification of six analytes in corncob hydrolysate, with intra- and inter-day variations less than 1.12%. This method is also convenient because it allows the rapid analysis of the primary products of biomass hydrolysis and carbohydrate degradation.

Liu X; Ai N; Zhang H; Lu M; Ji D; Yu F; Ji J

2012-05-01

140

Quantification of glucose, xylose, arabinose, furfural, and HMF in corncob hydrolysate by HPLC-PDA-ELSD.  

Science.gov (United States)

Lignocellulose and other carbohydrates are being studied extensively as potential renewable carbon sources for liquid biofuels and other valuable chemicals. In the present study, a simple, sensitive, selective, and reliable HPLC method using a photodiode array (PDA) detector and an evaporative light scattering detector (ELSD) was developed for the simultaneous determination of important sugars (D(+)-cellobiose, glucose, xylose, and arabinose), furfural and 5-hydroxymethylfurfural (5-HMF) in lignocellulose hydrolysate. The analysis was carried out on an Aminex HPX-87H column (250 mm × 4.6 mm, 5 ?m particle size). Ultra-pure water with 0.00035 M H(2)SO(4) was used as the mobile phase with a flow rate of 0.6 mL/min. The temperature of the ELSD drift tube was kept at 50 °C, the carrier gas pressure was 350 kPa, and the gain was set at 7. Furfural and 5-HMF were quantified on a PDA detector at 275 nm and 284 nm, respectively. The sugar concentrations were determined by ELSD. This method was validated for accuracy and precision. The regression equation revealed a good linear relationship (r(2) = 0.9986 ± 0.0012) within the test ranges. The method showed good reproducibility for the quantification of six analytes in corncob hydrolysate, with intra- and inter-day variations less than 1.12%. This method is also convenient because it allows the rapid analysis of the primary products of biomass hydrolysis and carbohydrate degradation. PMID:22516168

Liu, Xuejun; Ai, Ning; Zhang, Haiyan; Lu, Meizhen; Ji, Dengxiang; Yu, Fengwen; Ji, Jianbing

2012-04-01

 
 
 
 
141

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

2011-01-01

142

[Recycle of spent cells from anaerobic succinate fermentation].  

Science.gov (United States)

Spent cells recovered from anaerobic fermentation by Actinobacillus succinogenes were used as nitrogen source for succinic acid production. Three methods were investigated for cell wall-breaking. The results showed that enzymatic hydrolysis was more effective for higher succinic acid yield. When the enzymatic hydrolysate of spent cells was added to reach a total nitrogen concentration 1.11 g/L (equivalent to 10 g/L yeast extract), the succinic acid concentration was 42.0 g/L, but it increased slightly when enhancing the level of enzymatic hydrolysate. However, when 5 g/L yeast extract was supplemented with the enzymatic hydrolysate of spent cells, the succinic acid concentration reached 75.5 g/L after 36 hours and, the succinic acid productivity was 2.10 g/(L x h), which increased by 66.7% compared with the fermentation using 10 g/L yeast extract. Therefore, enzymatic hydrolysate of spent cells could replace 50% yeast extract in the original medium for succinic acid production. PMID:21141119

Bai, Xuefei; Chen, Kequan; Ye, Guizi; Huang, Xiumei; Li, Jian; Jiang, Min

2010-09-01

143

PROCESS FOR PRODUCTION OF AN ENZYMATIC PREPARATION FOR HYDROLYSIS OF CELLULOSE FROM LIGNOCELLULOSIC RESIDUES AND APPLICATION THEREOF IN THE PRODUCTION OF ETHANOL  

UK PubMed Central (United Kingdom)

The process of the present invention is based on the microbial production of enzymes from the growth of the fungus Penicillium funiculosum in a suitable culture medium with a cellulosic substrate. The process of the invention comprises in particular the fermentative treatment of a lignocellulosic substrate by means of a specially adapted fungus, for obtaining an enzymatic preparation capable of hydrolysing cellulose and hemicellulose for the production of ethanol.

DE CASTRO ALINE MACHADO; SANTANNA LIDIA MARIA MELO; PEREIRA JUNIOR NEI; GOMES ABSAI DA CONCEICAO; MENEZES EMERSON PIRES; SILVEIRA CLAUDIA JULIA GROPOSO; MOYSES DANUZA NOGUEIRA; BANDEIRA LUIZ FERNANDO MARTINS; MAEDA ROBERTO NOBUYUKI

144

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; Anderson Dwight; Levie Benjamin

2013-01-01

145

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

UK PubMed Central (United Kingdom)

UNLABELLED: 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 J; Anderson D; Levie B

2013-01-01

146

A chewy problem. Lignocellulose; Kein Zuckerschlecken. Lignozellulose  

Energy Technology Data Exchange (ETDEWEB)

Instead of gaining ethanol and other hydrocarbons from crops, biofuels of a new generation especially should be produced from vegetable wastes. Thus, chemists are looking for methods to gain sugar molecules from lignocellulose. Lignocellulose is a mixture of molecules which may lignify cell walls. The necessary enzymes still are expensive and not very stable. However, new solvents as well as biotechnology promise a solution.

Sanderson, Katharine

2012-03-15

147

Amine-catalyzed hydrolyses of cyclodextrin cinnamates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Hydrolyses of ?-cyclodextrin cinnamate (?CDC) and ?-cyclodextrin cinnamate were catalyzed by amines such as 1,4-diazabicyclo(2.2.2)octane, triethylamine, quinuclidine, piperidine, diisobutylamine, and n-butylamine. The rate constant of hydrolyses of the ?CDC-amine complexes follows the order: 1,4-di...

Komiyama, Makoto; Bender, Myron L.

148

Ethanol from lignocellulose; An overview  

Energy Technology Data Exchange (ETDEWEB)

Ethanol, a liquid fuel compatible with today's transportation system, can be produced by biological processes from lignocellulosic feedstocks. Biomass in an attractive feedstock for ethanol production because it is available in large quantities at low cost. Biological processes are very efficient, but each fraction of the lignocellulosic feedstock must be processed separately. Cellulose (a crystalline polymer of glucose), the structural core, comprises 40% of the feedstock. It is difficult to hydrolyze (break down) into glucose, but once formed, the glucose is readily fermented to ethanol. Cellulose can be hydrolyzed with either acid or enzymatic catalysts. Using acids, the chief problem is that conditions severe enough to promote hydrolysis also degrade the glucose, resulting in low (55%-80%) yields. Enzymatic processes are potentially much more efficient because enzymes catalyze only the hydrolysis reaction. However, these processes are much newer and less developed. Research is required to develop methods to make lignocellulose more digestible, to produce more active enzymes at lower cost, and to develop methods of hydrolysis where enzyme action is not inhibited by reaction end products. Approximately 30% of the feedstock is hemicellulose, which is largely made of xylan (a polymer of xylose). Xylan is easily hydrolyzed, but it is difficult to ferment to ethanol. Several potential methods of fermentation have been identified, but it is not yet clear which is the most promising. Lignin, the final major component, is a phenolic polymer that cannot be fermented to ethanol. However, it can be broken down to phenolic monomers, hydrotreated, and reacted with methanol to produce methyl aryl ethers, a high-octane gasoline additive. 21 refs., 11 figs., 1 tab.

Wright, J.D.

1987-07-01

149

Lime pretreatment of lignocellulosic biomass  

Science.gov (United States)

Lignocellulose is a valuable alternative energy source. The susceptibility of lignocellulosic biomass to enzymatic hydrolysis is constrained due to its structural features, so pretreatment is essential to enhance enzymatic digestibility. Of the chemicals used as pretreatment agents, it has been reported that alkalis improve biomass digestibility significantly. In comparison with other alkalis such as NaOH and ammonia, lime (calcium hydroxide) has many advantages; it is very inexpensive, is safe, and can be recovered by carbonating wash water. The effects of lime pretreatment were explored on switchgrass and poplar wood, representing herbaceous and woody biomass, respectively. The effects of pretreatment conditions (time, temperature, lime loading, water loading, particle size, and oxygen pressure) have been systematically studies. Lime alone enhances the digestibility of switchgrass significantly; under the recommended conditions, the 3-d total sugar (glucose + xylose) yields of lime-treated switchgrass were 7 times that of untreated sample. When treating poplar wood, lime must be combined with oxygen to achieve high digestibility; oxidative lime pretreatment increased the 3-d total sugar yield of poplar wood to 12 times that of untreated sample. In a fundamental study, to determine why lime pretreatment is effective, the effects of three structural features on enzymatic digestibility were studied: lignin content, acetyl content, and crystallinity index (CrI). Poplar wood was treated with peracetic acid, potassium hydroxide, and ball milling to produce model lignocelluloses with a broad spectrum of lignin contents, acetyl contents, and CrI, respectively. Enzymatic hydrolysis was performed on the model lignocelluloses to determine the digestibility. Correlations between lignin/carbohydrate ratio, acetyl/carbohydrate ratio, CrI and digestibility were developed. The 95% prediction intervals show that the correlations predict the 1-h and 3-d total sugar conversions of a biomass sample within a precision of 5% and 20%, respectively. The digestibility of a variety of lime-treated biomass and ball-milled alpha-cellulose was compared to the correlations determined from the model compounds. The agreement between the measured and predicted values shows that the correlations are satisfactory and the three structural features---lignin content, acetyl content, and CrI---are the major factors that determine enzymatic digestibility.

Chang, Shushien

150

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

151

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

Science.gov (United States)

A newly isolated Clostridium sp. strain RPT-4213 was found to produce butyrate under anaerobic conditions. Fermentations using Lactobacilli MRS Broth produced 9.47 g L-1 butyric acid from glucose (0.48 g/g glucose). However, the strain was not capable of utilizing five carbon sugars. To assess the a...

152

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

153

Fractionating recalcitrant lignocellulose at modest reaction conditions.  

UK PubMed Central (United Kingdom)

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

Zhang YH; Ding SY; Mielenz JR; Cui JB; Elander RT; Laser M; Himmel ME; McMillan JR; Lynd LR

2007-06-01

154

Fractionating Recalcitrant Lignocellulose at Modest Reaction Conditions  

Energy Technology Data Exchange (ETDEWEB)

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

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

2007-01-01

155

Biocatalytic conversion of lignocellulose to platform chemicals.  

UK PubMed Central (United Kingdom)

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.

Jäger G; Büchs J

2012-09-01

156

Food engineering residues: amino acid composition of hydrolysates and application for the decontamination of metal polluted soils  

Energy Technology Data Exchange (ETDEWEB)

Several residues of the brewing industry and slaughtering offals were investigated in order to evaluate their potential as raw materials for the hydrolytic preparation of amino acid containing solutions, applicable as extractants in amelioration processes for metal polluted soils. The residues were hydrolysed with 6 mol/L hydrochloric acid and the hydrolysates were analysed for their total nitrogen, TOC, amino acid and heavy metal contents. Then, the leaching capacities of the hydrolysates were examined in a series of batch tests with a contaminated soil. High amino acid yields in relation to the weight of the air-dried raw materials were achieved with blood meal (72.5%) and poultry feather meal (56.6%). The portion of the detected amino acids of the total organic carbon content of the hydrolysates ranged from 38.9% (brewer's spent grain) to 93.6% (blood meal). In extraction tests with hydrolysates adjusted to a total amino acid concentration of 60 mmol/L and to a pH value of 7.0, maximum extraction yields of 50.3% for copper (soil content 279 mg kg[sup -1]) and 38.7% for nickel (soil content 54 mg kg[sup -1]) were reached. An increase of the hydrolysate concentration and of the pH of an amino acid mixture resulted in higher solubilisation of the metals. (orig.)

Fischer, K. (GSF-Forschungszentrum, Inst. fuer Oekologische Chemie, Oberschleissheim (Germany) TU Muenchen, Lehrstuhl fuer Oekologische Chemie, Freising-Weihenstephan (Germany)); Riemschneider, P. (GSF-Forschungszentrum, Inst. fuer Oekologische Chemie, Oberschleissheim (Germany)); Bieniek, D. (GSF-Forschungszentrum, Inst. fuer Oekologische Chemie, Oberschleissheim (Germany)); Kettrup, A. (GSF-Forschungszentrum, Inst. fuer Oekologische Chemie, Oberschleissheim (Germany) TU Muenchen, Lehrstuhl fuer Oekologische Chemie, Freising-Weihenstephan (Germany))

1994-11-01

157

A feasibility study on the multistage process for the oxalic acid pretreatment of a lignocellulosic biomass using electrodialysis.  

Science.gov (United States)

The present study investigated the feasibility of the recovery and reuse oxalic acid in a multistage process for the pretreatment of a lignocellulosic biomass. Electrodialysis (ED), an electrochemical process using ion exchange membranes, was used to recover and reuse oxalic acid in the multistage process. The ED optimal condition for recover oxalic acid was potential of 10V and pH 2.2 in synthetic solutions. The recovery efficiency of oxalic acid from hydrolysates reached 100% at potential of 10V. The power consumption to treat 1mol of oxalic acid was estimated to be 41.0wh. At the same time, ethanol production increased up to 19g/L in the ED-treated hydrolysate, corresponding to ethanol productivity of 0.27g/L/h. It was clearly shown that bioethanol fermentation efficiency increased using the ED process, due to a small loss of fermentable sugar and a significantly high removal of inhibitory chemicals. PMID:23306131

Lee, Hong-Joo; Ahn, Sung Ju; Seo, Young-Jun; Lee, Jae-Won

2012-12-17

158

Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents.  

UK PubMed Central (United Kingdom)

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.

Ghanbari R; Ebrahimpour A; Abdul-Hamid A; Ismail A; Saari N

2012-01-01

159

Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents  

Directory of Open Access Journals (Sweden)

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; Afshin Ebrahimpour; Azizah Abdul-Hamid; Amin Ismail; Nazamid Saari

2012-01-01

160

Actinopyga lecanora Hydrolysates as Natural Antibacterial Agents.  

Science.gov (United States)

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. PMID:23222684

Ghanbari, Raheleh; Ebrahimpour, Afshin; Abdul-Hamid, Azizah; Ismail, Amin; Saari, Nazamid

2012-12-07

 
 
 
 
161

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

162

Ethanol from lignocellulose - An overview  

Energy Technology Data Exchange (ETDEWEB)

Ethanol, a liquid fuel compatible with today's transportation system, can be produced by biological processes from lingocellulosic feedstocks. Biomass is an attractive feedstock for ethanol production because it is available in large quantities at low cost. Biological processes are very efficient, but each fraction of the lignocellulosic feedstock must be processed separately. Cellulose (a crystalline polymer of glucose), the structural core, comprises 40% of the feedstock. It is difficult to hydrolyze (break down) into glucose, but once formed, the glucose is readily fermented to ethanol. Cellulose can be hydrolyzed with either acid or enzymatic catalysts. Using acids, the chief problem is that conditions severe enough to promote hydrolysis also degrade the glucose, resulting in low (55%-80%) yields. Enzymatic processes are potentially much more efficient because enzymes catalyze only the hydrolysis reaction. However, these processes are much newer and less developed. Research is required to develop methods to make lignocellulose more digestible, to produce more active enzymes at lower cost, and to develop methods of hydrolysis where enzyme action is not inhibited by reaction end products. Approximately 30% of the feedstock is hemicellulose, which is largely made of xylan (a polymer of xylose). Xylan is easily hydrolyzed, but it is difficult to ferment to ethanol. Several potential methods of fermentation have been identified, but it is not yet clear which is the most promising. Lignin, the final major component, is a phenolic polymer that cannot be fermented to ethanol. However, it can be broken down to phenolic monomers, hydrotreated, and reacted with methanol to produce methyl aryl ethers, a high-octane gasoline additive.

Wright, J.D.

1987-01-01

163

PROCESS FOR PRODUCING A SHRIMP HYDROLYSATE USING ELECTRODIALYSIS  

UK PubMed Central (United Kingdom)

The present invention provides a process for the production of a shrimp hydrolysate comprising (a) contacting a shrimp proteinaceous material with a protease and allowing proteolysis to take place, thereby generating a hydrolysate (b) increasing the dry matter content of said hydrolysate to 30-44% and then (c) reducing the NaCl content of said hydrolysate to less than 4% through electrodialysis. Also provided are a hydrolysate obtainable by such a process, uses thereof and methods of treatment.

RAUO JARAN

164

Develop Biological Systems for Lignocellulose Conversion.  

Science.gov (United States)

Two aspects of lignocellulose bioprocessing are explored: the potential for using a lignin-degrading system to partially delignify substrates in order to improve polysaccharidase digestibility or to improve other properties; and the possibility of obtaini...

T. K. Kirk J. G. Zeikus

1978-01-01

165

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

166

Influence of Retardants to Burning Lignocellulosic Materials  

Science.gov (United States)

The paper deals with monitoring retardant changes of lignocellulosic materials. Combustion of lignocellulosic materials and fire-technical characteristics are described. In assessing the retarding effect of salt NH4H2PO4, fire-technical characteristics as limiting oxygen index (LOI) were measured, and by using thermoanalytical TG and DSC methods. High-temperature process of cellulose degradation at various flame concentrations was studied.

Tureková, Ivana; Harangozó, Jozef; Martinka, Jozef

2011-01-01

167

Lignocellulosic Biomass Conversion: Status and Prospects  

Science.gov (United States)

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

Scarlata, C. (Christopher); Sluiter, Amie

2011-04-25

168

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

169

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

UK PubMed Central (United Kingdom)

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

Canilha L; Carvalho W; Felipe Md; de Almeida E Silva JB

2008-04-01

170

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

UK PubMed Central (United Kingdom)

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

Tanimura K; Nakayama H; Tanaka T; Kondo A

2013-08-01

171

Lignocellulosic biomass pretreatment using AFEX.  

UK PubMed Central (United Kingdom)

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 V; Bals B; Chundawat SP; Marshall D; Dale BE

2009-01-01

172

Acetylation of woody lignocellulose: significance and regulation.  

UK PubMed Central (United Kingdom)

Non-cellulosic cell wall polysaccharides constitute approximately one quarter of usable biomass for human exploitation. In contrast to cellulose, these components are usually substituted by O-acetyl groups, which affect their properties and interactions with other polymers, thus affecting their solubility and extractability. However, details of these interactions are still largely obscure. Moreover, polysaccharide hydrolysis to constituent monosaccharides is hampered by the presence of O-acetyl groups, necessitating either enzymatic (esterase) or chemical de-acetylation, increasing the costs and chemical consumption. Reduction of polysaccharide acetyl content in planta is a way to modify lignocellulose toward improved saccharification. In this review we: (1) summarize literature on lignocellulose acetylation in different tree species, (2) present data and current hypotheses concerning the role of O-acetylation in determining woody lignocellulose properties, (3) describe plant proteins involved in lignocellulose O-acetylation, (4) give examples of microbial enzymes capable to de-acetylate lignocellulose, and (5) discuss prospects for exploiting these enzymes in planta to modify xylan acetylation.

Pawar PM; Koutaniemi S; Tenkanen M; Mellerowicz EJ

2013-01-01

173

Co-production of bioethanol, lactic acid, electricity and heat from lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

Large-scale CO2 abatement is a very important issue in our society. Many options are open to reach this goal including the bioconversion of biomass into either energy carriers or bulk chemicals. In this respect, bioethanol and lactic acid are excellent candidates as liquid fuel and bulk chemical, respectively. As for the biomass to be used as feedstock, potential interference with human consumption should be avoided. Hence, lignocellulosic biomass is the preferred option for future large scale processes. Bioethanol can be applied directly or in the form of ETBE in blends with petrol; lactic acid is a renewable alternative for petrochemical solvents and for production of polylactic acid (PLA) to replace petrochemical packaging materials and other synthetic materials. The preparation of fermentable sugars from lignocellulose is a major challenge for both bioethanol and lactic acid production and requires integral optimization of the trajectory from feedstock through fermentation to product recovery. The above issues have been addressed in the Netherlands in a 4.5-year R and D project (2002-2006) by a consortium of industries and R and D institutes in the framework of the EET-program. The overall project objective was to develop and evaluate technologies for the use of lignocellulose as feedstock for bioethanol and lactic acid production. Wheat straw was selected as the model feedstock. Major R and D themes in the project were: Physical/chemical pretreatment for mobilization of (hemi)cellulose from the lignocellulose matrix. Both mild acid pressurized hot water and mild alkaline pretreatment were studied; Optimization of enzymatic cellulose hydrolysis with commercially available enzymes; Use of lignocellulose hydrolysates for ethanol and lactic acid fermentation including optimization of the fermentation process setup and process conditions; Combined Heat and Power (CHP) generation from fermentation residues including evaluation of the potential utilisation of ashes as secondary building material or fertilizer; System modelling and evaluation and integral plant design including economic evaluation; Ecologic evaluation in the form of a screening LCA; Specification and formulation of bioethanol in blends with petrol.

Reith, J.H.; De Bont, J.A.M. (eds.) [ECN Biomass, Coal and Environmental Research, Petten (Netherlands)

2007-09-15

174

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

175

Ethanol production from lignocellulosic biomass  

Energy Technology Data Exchange (ETDEWEB)

When added directly to gasoline or used to produce ethyl tertiary butyl ether (ETBE) for gasoline blends, ethanol improves combustion and reduces tailpipe carbon monoxide and hydrocarbon emissions that contribute to ozone formation and smog. ETBE also reduces fuel evaporation that contributes to smog formation. Enough ethanol could be derived from domestic sources of dedicated herbaceous and woody energy crops, collectible waste materials, and other sources of lignocellulosic biomass to potentially replace all gasoline used in the United States. Furthermore, because the lignin fraction can be burned to power the conversion process, few if any, fossil resources are needed to produce ethanol from biomass, and ethanol`s contribution to carbon dioxide buildup in the atmosphere is 10% or less than that of gasoline. Based on technoeconomic analyses and R and D results, efforts have been directed at enzyme-based processes because of the technology`s status and the opportunities to lower the cost to be competitive with gasoline. The cost of ethanol production has been reduced from about $3.60/gal in 1980 to less than $1.22/gal now. Research is being carried out to further improve biomass pretreatment, cellulose enzyme production, cellulose conversion, five-carbon sugar utilization, lignin use, and product recovery, with the goal of reducing the cost to $0.67/gal at the plant gate. Major breakthroughs have been achieved recently on technologies for pretreatment and xylose fermentation. Because ethanol production from biomass is now competitive for use in direct blends with gasoline (particularly for niche applications), bench scale integrated processes are being operated, and construction of a 1 ton/d PDU is being completed at NREL to allow industrial partners to obtain data that are vital to commercial applications. Partnerships have been formed with New Energy Company of Indiana, Amoco Corporation, and others to rapidly apply the technology.

Wyman, C.E. [National Renewable Energy Lab., Golden, CO (United States). Alternative Fuels Division

1995-10-01

176

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

UK PubMed Central (United Kingdom)

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

Madhavan A; Srivastava A; Kondo A; Bisaria VS

2012-03-01

177

GENETICALLY MODIFIED LIGNOCELLULOSIC BIOMASS FOR IMPROVEMENT OF ETHANOL PRODUCTION  

Directory of Open Access Journals (Sweden)

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

Qijun Wang; Shengdong Zhu

2010-01-01

178

Novel biomixtures based on local Mediterranean lignocellulosic materials: evaluation for use in biobed systems.  

UK PubMed Central (United Kingdom)

The composition of biomixtures strongly affect the efficacy of biobeds. Typically, biomixture consists of peat (or compost), straw (STR) and topsoil (1:2:1 by volume). Straw guarantees a continuous supply of nutrients and high microbial activity. However, in south Europe other lignocellulosic materials including sunflower crop residues (SFR), olive leaves, grape stalks (GS), orange peels, corn cobs (CC) and spent mushroom substrate (SMS) are also readily available at no cost. Their potential utilization in biomixtures instead of STR was tested in pesticide degradation and adsorption studies. The microbial activity in these biomixtures was also assessed. The GS-biomixture was the most efficient in pesticide degradation, while CC- and SFR-biomixtures showed comparable degrading efficacy with the STR-biomixture. The SMS-biomixture was also highly efficient in degrading the pesticide mixture with degradation rates being correlated with the proportion of SMS in the biomixture. Microbial respiration was positively correlated with the degradation rates of metalaxyl, azoxystrobin and chlorpyrifos, compared to phenoloxidase which showed no correlation. Biomixtures containing alternative lignocellulosic materials showed a higher adsorption affinity for terbuthylazine and metribuzin compared to the STR-biomixture. We provide first evidence that STR can be substituted in biomixtures by other lignocellulosic materials which are readily available in south Europe.

Karanasios E; Tsiropoulos NG; Karpouzas DG; Menkissoglu-Spiroudi U

2010-08-01

179

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; IS HELIANTI; NIKNIK NURHAYATI

2008-01-01

180

Semantic text mining support for lignocellulose research.  

UK PubMed Central (United Kingdom)

BACKGROUND: Biofuels produced from biomass are considered to be promising sustainable alternatives to fossil fuels. The conversion of lignocellulose into fermentable sugars for biofuels production requires the use of enzyme cocktails that can efficiently and economically hydrolyze lignocellulosic biomass. As many fungi naturally break down lignocellulose, the identification and characterization of the enzymes involved is a key challenge in the research and development of biomass-derived products and fuels. One approach to meeting this challenge is to mine the rapidly-expanding repertoire of microbial genomes for enzymes with the appropriate catalytic properties. RESULTS: Semantic technologies, including natural language processing, ontologies, semantic Web services and Web-based collaboration tools, promise to support users in handling complex data, thereby facilitating knowledge-intensive tasks. An ongoing challenge is to select the appropriate technologies and combine them in a coherent system that brings measurable improvements to the users. We present our ongoing development of a semantic infrastructure in support of genomics-based lignocellulose research. Part of this effort is the automated curation of knowledge from information on fungal enzymes that is available in the literature and genome resources. CONCLUSIONS: Working closely with fungal biology researchers who manually curate the existing literature, we developed ontological natural language processing pipelines integrated in a Web-based interface to assist them in two main tasks: mining the literature for relevant knowledge, and at the same time providing rich and semantically linked information.

Meurs MJ; Murphy C; Morgenstern I; Butler G; Powlowski J; Tsang A; Witte R

2012-01-01

 
 
 
 
181

LIGNOCELLULOSIC BIOMASS SACCHARIFICATION PRE-TREATMENT DEVICE  

UK PubMed Central (United Kingdom)

Provided is a lignocellulosic biomass saccharification pre-treatment device that can easily recover and re-use aqueous ammonia that is used for pre-treatment when saccharifying lignocellulosic biomass. The lignocellulosic biomass saccharification pre-treatment device is provided with a mixing means (2) that mixes the lignocellulosic biomass and ammonia, a heating means (3) that heats the biomass-ammonia mixture, a separating means (4) that separates ammonia gas from the biomass-ammonia mixture and obtains a biomass-water mixture, and a transport means (6) that transports the biomass-water mixture to a post-process (5). The device is provided with an aqueous ammonia-supplying means (8) that supplies aqueous ammonia to the mixing means (2), an ammonia recovery means (20) that recovers the ammonia gas as aqueous ammonia, a heat of solution recovery means (24) that recovers the heat of solution generated when the ammonia gas is dissolved in water, and a heat pump means (30) that uses at least said heat of solution as a heat source and generates heat that is supplied to the heating means (3).

BABA TSUYOSHI

182

Conversion of Lignocellulosic Material into Fermentable Sugars  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 fut...

Mohammed, Asem Hassan

183

Assessment of Bacteria for Lignocellulose Transformations.  

Science.gov (United States)

In this research approximately 50 eubacteria were isolated and screened for their abilities to convert 14C-(LIGNIN)-lignocelluloses to 14CO2. Nine of the bacteria were able to perform this conversion. The best lignin degrading bacterium isolated was a Bac...

R. L. Crawford

1979-01-01

184

Semantic text mining support for lignocellulose research  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Biofuels produced from biomass are considered to be promising sustainable alternatives to fossil fuels. The conversion of lignocellulose into fermentable sugars for biofuels production requires the use of enzyme cocktails that can efficiently and economically hydrolyze lignocellulosic biomass. As many fungi naturally break down lignocellulose, the identification and characterization of the enzymes involved is a key challenge in the research and development of biomass-derived products and fuels. One approach to meeting this challenge is to mine the rapidly-expanding repertoire of microbial genomes for enzymes with the appropriate catalytic properties. Results Semantic technologies, including natural language processing, ontologies, semantic Web services and Web-based collaboration tools, promise to support users in handling complex data, thereby facilitating knowledge-intensive tasks. An ongoing challenge is to select the appropriate technologies and combine them in a coherent system that brings measurable improvements to the users. We present our ongoing development of a semantic infrastructure in support of genomics-based lignocellulose research. Part of this effort is the automated curation of knowledge from information on fungal enzymes that is available in the literature and genome resources. Conclusions Working closely with fungal biology researchers who manually curate the existing literature, we developed ontological natural language processing pipelines integrated in a Web-based interface to assist them in two main tasks: mining the literature for relevant knowledge, and at the same time providing rich and semantically linked information.

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

2012-01-01

185

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

186

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.

187

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

2006-01-01

188

[Protein hydrolysate as a dietetic resource  

UK PubMed Central (United Kingdom)

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 (p< 0.05) concerning the application of the three hydrolysates 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.

Silva ME; Mazzilli RN; Barbieri D

1998-05-01

189

Thermorheological complexity and fragility in plasticized lignocellulose.  

UK PubMed Central (United Kingdom)

It is demonstrated that plasticized lignocellulose fails to satisfy classic criteria normally required to validate time/temperature superposition (TTS) in dynamic mechanical analysis (DMA). However, insightful relaxation behavior is available and dismissing it would be a mistake. TTS was applied to Liriodendron tulipifera wood using parallel plate compressive-torsion DMA with specimens immersed in different organic liquids, ranging from weak to strong swelling power. While all storage moduli shifted smoothly, thermorheological complexity was detected in loss modulus shift failures, which themselves must reflect unknown structural features. Storage modulus shift factors clearly distinguished solvent specific relaxation behavior and interpretations through the WLF model or through fragility (cooperativity) analysis are useful. However, it is demonstrated that fragility analysis is preferred and solvents of different swelling power are compared. Coupled with other methods, TTS and fragility analysis warrant further development as a means to improve the understanding of structure/property relationships in plasticized lignocellulose.

Chowdhury S; Frazier CE

2013-04-01

190

Lignocelluloses conversion: the Soustons site example  

Energy Technology Data Exchange (ETDEWEB)

The lignocellulose biomass conversion in acetone-butanol in Soustons site (France) uses an enzymatic hydrolysis technology. The biomass thermal and mechanical pre-treatment allows enzymatic hydrolysis of cellulose fraction, for glucose and xylose formation (cellulases are produced by an aerobic fermentation of a selected variety of Trichoderma reesei mushroom) . This is followed by an anaerobic fermentation with Clostridium acetobutylicum for a 66% butanol 33% acetone mixture. (A.B.). 2 figs., 2 insets.

Ballerini, D.; Renault, P.; Vandecasteele, J.P. (Institut Francais du Petrole (IFP), 92 - Rueil-Malmaison (France)); Nativel, F.; Rebeller, M.

1992-06-01

191

Stabilization of wood and lignocellulose materials  

International Nuclear Information System (INIS)

A method is described consisting in impregnation of wood or of lignocellulose materials with a mixture containing the unsaturated monomers styrene and acrylnitrile, organic solvents and swelling agents, and 1,3-butadiene and/or 2-chloro-1,3-butadiene and/or 1,3-cyclopentadiene at an amount of 40 volume per cent in the initial mixture. Polymerization is effected by ionizing radiation. (B.S.)

1973-01-01

192

Combining inhibitor tolerance and D-xylose fermentation in industrial Saccharomyces cerevisiae for efficient lignocellulose-based bioethanol production.  

UK PubMed Central (United Kingdom)

BACKGROUND: In addition to efficient pentose utilization, high inhibitor tolerance is a key trait required in any organism used for economically viable industrial bioethanol production with lignocellulose biomass. Although recent work has succeeded in establishing efficient xylose fermentation in robust industrial Saccharomyces cerevisiae strains, the resulting strains still lacked sufficient inhibitor tolerance for efficient sugar fermentation in lignocellulose hydrolysates. The aim of the present work was to combine high xylose fermentation activity and high inhibitor tolerance in a single industrial yeast strain. RESULTS: We have screened 580 yeast strains for high inhibitor tolerance using undetoxified acid-pretreated spruce hydrolysate and identified a triploid industrial baker's yeast strain as having the highest inhibitor tolerance. From this strain, a mating competent diploid segregant with even higher inhibitor tolerance was obtained. It was crossed with the recently developed D-xylose fermenting diploid industrial strain GS1.11-26, with the Ethanol Red genetic background. Screening of 819 diploid segregants from the tetraploid hybrid resulted in two strains, GSF335 and GSF767, combining high inhibitor tolerance and efficient xylose fermentation. In a parallel approach, meiotic recombination of GS1.11-26 with a haploid segregant of Ethanol Red and screening of 104 segregants resulted in a similar inhibitor tolerant diploid strain, GSE16. The three superior strains exhibited significantly improved tolerance to inhibitors in spruce hydrolysate, higher glucose consumption rates, higher aerobic growth rates and higher maximal ethanol accumulation capacity in very-high gravity fermentation, compared to GS1.11-26. In complex medium, the D-xylose utilization rate by the three superior strains ranged from 0.36 to 0.67 g/g DW/h, which was lower than that of GS1.11-26 (1.10 g/g DW/h). On the other hand, in batch fermentation of undetoxified acid-pretreated spruce hydrolysate, the three superior strains showed comparable D-xylose utilization rates as GS1.11-26, probably because of their higher inhibitor tolerance. They produced up to 23% more ethanol compared to Ethanol Red. CONCLUSIONS: We have successfully constructed three superior industrial S. cerevisiae strains that combine efficient D-xylose utilization with high inhibitor tolerance. Since the background strain Ethanol Red has a proven record of successful industrial application, the three new superior strains have strong potential for direct application in industrial bioethanol production.

Demeke MM; Dumortier F; Li Y; Broeckx T; Foulquié-Moreno MR; Thevelein JM

2013-08-01

193

Torrefaction of non-lignocellulose biomass waste  

Energy Technology Data Exchange (ETDEWEB)

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

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

2012-02-15

194

Fungal Bioconversion of Lignocellulosic Residues; Opportunities & Perspectives  

Directory of Open Access Journals (Sweden)

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

195

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

196

Brewer's spent grain as raw material for lactic acid production by Lactobacillus delbrueckii.  

Science.gov (United States)

Chemically pre-treated brewer's spent grain was saccharified with cellulase producing a hydrolysate with approx. 50 g glucose l(-1). This hydrolysate was used as a fermentation medium without any nutrient supplementation by Lactobacillus delbrueckii, which produced L-lactic acid (5.4 g l(-1)) at 0.73 g g(-1) glucose consumed (73% efficiency). An inoculum of 1 g dry cells l(-1) gave the best yield of the process, but the pH decrease affected the microorganism capacity to consume glucose and convert it into lactic acid. PMID:17700998

Mussatto, Solange I; Fernandes, Marcela; Dragone, Giuliano; Mancilha, Ismael M; Roberto, Inês C

2007-08-14

197

Dipeptidyl peptidase-IV inhibitory activity of dairy protein hydrolysates  

UK PubMed Central (United Kingdom)

Dipeptidyl peptidase (DPP)-IV inhibitors are promising new therapies for type 2 diabetes. Currently, these inhibitors are only available as synthetic drugs. Therefore, the aim of the present study was to investigate dairy protein hydrolysates as natural sources of DPP-IV inhibitors. While the DPP-IV inhibitory activity of sodium caseinate, skim milk powder and milk protein concentrate hydrolysates increased over the course of in vitro pepsin-pancreatin digestion, whey protein isolate (WPI) hydrolysate showed highest inhibitory activity following peptic digestion. Hydrolysates produced from sodium caseinate using 11 different proteases displayed higher inhibitory activity than most WPI hydrolysates. However, among all enzymatic treatments investigated, peptic digestion of WPI resulted in the greatest DPP-IV inhibitory activity (IC50 of 0.075 mg mL?1). Fractionation of the hydrolysates by size generally improved the inhibitory activity. This study shows that peptides with DPP-IV inhibitory activity can be generated from dairy ingredients.

Lacroix IME; Li-Chan ECY

2012-08-01

198

Spent refractory reuse  

Energy Technology Data Exchange (ETDEWEB)

The Albany Research Center is conducting work on spent refractory recycling/alternate use, including a review of refractory usage and current recycling/disposal practices. Research has focused on the hazardous nature of some spent refractory materials, with emphasis on lead pickup. Information on the issues associated with the reuse of spent refractories will be presented, including those associated with hazardous materials.

Bennett, J.P.; Kwong, K.S.; Clark, J.A. [Albany Research Center, Albany, NY (United States)] [and others

1996-12-31

199

PROTEIN HYDROLYSATES IN SPORTS AND EXERCISE: A BRIEF REVIEW  

Directory of Open Access Journals (Sweden)

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

2004-01-01

200

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

UK PubMed Central (United Kingdom)

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

Skerker JM; Leon D; Price MN; Mar JS; Tarjan DR; Wetmore KM; Deutschbauer AM; Baumohl JK; Bauer S; Ibáñez AB; Mitchell VD; Wu CH; Hu P; Hazen T; Arkin AP

2013-01-01

 
 
 
 
201

Collagen hydrolysate based collagen/hydroxyapatite composite materials  

Science.gov (United States)

The aim of this study was to study the influence of collagen hydrolysate (HAS) on the formation of ternary collagen-hydrolysate/hydroxyapatite composite materials (COLL-HAS/HA). During the precipitation process of HA, a large amount of brushite is resulted at pH = 7 but, practically pure HA is obtained at pH ? 8. The FTIR data reveal the duplication of the most important collagen absorption bands due to the presence of the collagen hydrolysate. The presence of collagen hydrolysate is beneficial for the management of bone and joint disorders such as osteoarthritis and osteoporosis.

Ficai, Anton; Albu, Madalina Georgiana; Birsan, Mihaela; Sonmez, Maria; Ficai, Denisa; Trandafir, Viorica; Andronescu, Ecaterina

2013-04-01

202

Fermentation of dried distillers' grains and solubles (DDGS) hydrolysates to solvents and value-added products by solventogenic clostridia.  

Science.gov (United States)

Pretreatment and hydrolysis of lignocellulosic biomass using either dilute acid, liquid hot water (LHW), or ammonium fiber expansion (AFEX) results in a complex mixture of sugars such as hexoses (glucose, galactose, mannose), and pentoses (xylose, arabinose). A detailed description of the utilization of representative mixed sugar streams (pentoses and hexoses) and their sugar preferences by the solventogenic clostridia (Clostridium beijerinckii BA101, C. acetobutylicum 260, C. acetobutylicum 824, Clostridium saccharobutylicum 262, and C. butylicum 592) is presented. In these experiments, all the sugars were utilized concurrently throughout the fermentation, although the rate of sugar utilization was sugar specific. For all clostridia tested, the rate of glucose utilization was higher than for the other sugars in the mixture. In addition, the availability of excess fermentable sugars in the bioreactor is necessary for both the onset and the maintenance of solvent production otherwise the fermentation will become acidogenic leading to premature termination of the fermentation process. During an investigation on the effect of some of the known lignocellulosic hydrolysate inhibitors on the growth and ABE production by clostridia, ferulic and p-coumaric acids were found to be potent inhibitors of growth and ABE production. Interestingly, furfural and HMF were not inhibitory to the solventogenic clostridia; rather they had a stimulatory effect on growth and ABE production at concentrations up to 2.0g/L. PMID:17967532

Ezeji, Thaddeus; Blaschek, Hans P

2007-10-29

203

Effect of various factors on ethanol yields from lignocellulosic biomass by Thermoanaerobacterium AK??.  

UK PubMed Central (United Kingdom)

The ethanol production capacity from sugars and lignocellulosic biomass hydrolysates (HL) by Thermoanaerobacterium strain AK(17) was studied in batch cultures. The strain converts various carbohydrates to, acetate, ethanol, hydrogen, and carbon dioxide. Ethanol yields on glucose and xylose were 1.5 and 1.1 mol/mol sugars, respectively. Increased initial glucose concentration inhibited glucose degradation and end product formation leveled off at 30 mM concentrations. Ethanol production from 5 g L(-1) of complex biomass HL (grass, hemp, wheat straw, newspaper, and cellulose) (Whatman paper) pretreated with acid (0.50% H(2) SO(4)), base (0.50% NaOH), and without acid/base (control) and the enzymes Celluclast and Novozyme 188 (0.1 mL g(-1) dw; 70 and 25 U g(-1) of Celluclast and Novozyme 188, respectively) was investigated. Highest ethanol yields (43.0 mM) were obtained on cellulose but lowest on hemp leafs (3.6 mM). Chemical pretreatment increased ethanol yields substantially from lignocellulosic biomass but not from cellulose. The influence of various factors (HL, enzyme, and acid/alkaline concentrations) on end-product formation from 5 g L(-1) of grass and cellulose was further studied to optimize ethanol production. Highest ethanol yields (5.5 and 8.6 mM ethanol g(-1) grass and cellulose, respectively) were obtained at very low HL concentrations (2.5 g L(-1)); with 0.25% acid/alkali (v/v) and 0.1 mL g(-1) enzyme concentrations. Inhibitory effects of furfural and hydroxymethylfurfural during glucose fermentation, revealed a total inhibition in end product formation from glucose at 4 and 6 g L(-1), respectively.

Almarsdottir AR; Sigurbjornsdottir MA; Orlygsson J

2012-03-01

204

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 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 hy (more) drolysate, 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.

2006-03-01

205

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

206

Extraction of sugars from lignocellulose of corncobs  

Energy Technology Data Exchange (ETDEWEB)

The extraction rate of sugars from the surface of corncobs changed depending on the liquid ratio (r) of the system; increasing r by 2 units decreased the equilibrium concentration of sugar in the extraction by 1.20-1.25 times. An increase in temperature from 20 degrees to 80 degrees intensified the extraction process of sugar from lignocellulose of corncobs and reduced considerably the time of equilibrium sugar concentration in the extraction. The coefficient of mass transfer in the process increased with increasing temperature and r as determined by the method developed by E.L. Glazkova and A.I. Kunina (1973).

Abramyants, S.V.; Smolyakov, V.P.

1981-01-01

207

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

208

Intestinal protective effect of a commercial fish protein hydrolysate preparation.  

UK PubMed Central (United Kingdom)

OBJECTIVES: A partially hydrolysed, dried, product of pacific whiting fish is marketed as a health food supplement supporting 'intestinal health'. Scientific data supporting these claims are severely limited. We, therefore, examined if it influenced intestinal injury caused by the NSAID, indomethacin. METHODS: Effects of fish hydrolysate on proliferation ([3H]-thymidine) and indomethacin-induced apoptosis (active caspase-3-immunostaining) utilised HT29 cells. In vivo studies used mice (n=8/group). 4/6 groups had fish hydrolysate (25 or 50 mg/ml) supplemented to their drinking water for 7 days. All mice received indomethacin (85 mg/kg subcutaneously) or placebo, 12 h before killing. Small intestinal injury was assessed using morphometry and morphology, proliferation (crypt BrdU labelling ) and apoptosis (active caspase-3 immunostaining). RESULTS: Fish hydrolysate stimulated proliferation of HT29 cells. Apoptosis increased 3-fold following incubation with indomethacin but co-presence of fish hydrolysate truncated this effect by 40% (p<0.01). In mice, fish hydrolysate reduced the villus damaging effects of indomethacin by 60% (p<0.05). Indomethacin increased intestinal proliferation by 65%, irrespective of presence of hydrolysate. In contrast, intestinal caspase-3 activity increased by 83% in animals given indomethacin but this rise was truncated by 70% by co-presence of hydrolysate (p<0.01). CONCLUSION: This natural bioactive product reduced apoptosis and the gut damaging effects of indomethacin.

Marchbank T; Elia G; Playford RJ

2009-06-01

209

MEHTOD FOR PRODUCING ENZYMATIC FISH PROTEIN HYDROLYSATE  

UK PubMed Central (United Kingdom)

The invention relates to the food industry, medical and veterinary biotechnology, in particular to a method for producing an enzymatic fish protein hydrolysate and can be used for producing medicated products, food and feed additives, nutritive media for cultivating microorganisms and eukaryote cells. The aim of said invention is to obtain a final low-ash (salt) containing-product, reduce the length of production process cycles, and to improve the taste properties of the thus obtained product by removing a specific odour. The inventive method for producing the enzymatic fish protein-based hydrolysate consists in producing a protein-containing blend from fish entrails or by mixing said entrails and fish trunks. The hydrolysis of said blend is carried out directly or by mixing it with water. Potassium hydroxide is used in the form of an alkaline agent, an acid agent being embodied in the form of orthophosphoric acid. The final cleaning of the product (removal of pigments, specific fish odour and taste) is carried out by means of chromatography on Amberlight XAD-type carriers (France).

DUDKIN Sergey Marovich; ERMOLIN Gennadiy Andreevich; MEYNERT Andrian Georgievich

210

Biphasic biomethanation of wood-hydrolysate effluent.  

Science.gov (United States)

The dissolving pulp industry, spread throughout the world, is the principal source of wood-hydrolysate effluent rich in hemicelluloses. This effluent is the major source of pollution in the industry. COD and BOD5 values of the effluent range from 60,000 to 103,000 and 42,000 to 78,000 mg/l respectively. Biomethanation of this effluent is the best possible treatment option for reducing the COD load and recovering the bioenergy embedded in the effluent. This paper deals with the study on the biphasic biomethanation of the wood-hydrolysate in upflow acidogenic reactor coupled with anaerobic filter methanogenic reactor. The two reactors were operated at organic loading rates of 69.6 and 30.1 g COD/l/d respectively. The overall COD, hemicelluloses and lignin reductions, and methane generation were observed to be 88%, 92%, 82% and 6.5 l/l reactor volume/d respectively. The relative size of the biphasic, anaerobic filter (mono-phasic) and upflow anaerobic sludge blanket (mono-phasic) reactors is found to be 1:1.6:2.03 respectively. PMID:10595449

Chakrabarti, S K; Roychoudhury, P K; Bajpai, P K

211

Biphasic biomethanation of wood-hydrolysate effluent.  

UK PubMed Central (United Kingdom)

The dissolving pulp industry, spread throughout the world, is the principal source of wood-hydrolysate effluent rich in hemicelluloses. This effluent is the major source of pollution in the industry. COD and BOD5 values of the effluent range from 60,000 to 103,000 and 42,000 to 78,000 mg/l respectively. Biomethanation of this effluent is the best possible treatment option for reducing the COD load and recovering the bioenergy embedded in the effluent. This paper deals with the study on the biphasic biomethanation of the wood-hydrolysate in upflow acidogenic reactor coupled with anaerobic filter methanogenic reactor. The two reactors were operated at organic loading rates of 69.6 and 30.1 g COD/l/d respectively. The overall COD, hemicelluloses and lignin reductions, and methane generation were observed to be 88%, 92%, 82% and 6.5 l/l reactor volume/d respectively. The relative size of the biphasic, anaerobic filter (mono-phasic) and upflow anaerobic sludge blanket (mono-phasic) reactors is found to be 1:1.6:2.03 respectively.

Chakrabarti SK; Roychoudhury PK; Bajpai PK

1999-09-01

212

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; M.S. Mellado; C. Prentice-Hernández

2011-01-01

213

Enzymology of lignocellulose bioconversion by Streptomyces viridosporus  

International Nuclear Information System (INIS)

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

1989-01-01

214

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

215

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 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 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. (more) 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.

2008-01-01

216

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

Directory of Open Access Journals (Sweden)

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

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

2008-01-01

217

Possible application of brewer’s spent grain in biotechnology  

Directory of Open Access Journals (Sweden)

Full Text Available Brewer’s spent grain is the major by-product in beer production. It is produced in large quantities (20 kg per 100 liters of produced beer) throughout the year at a low cost or no cost, and due to its high protein and carbohydrates content it can be used as a raw material in biotechnology. Biotechnological processes based on renewable agro-industrial by-products have ecological (zero CO2 emission, eco-friendly by-products) and economical (cheap raw materials and reduction of storage costs) advantages. The use of brewer’s spent grain is still limited, being basically used as animal feed. Researchers are trying to improve the application of brewer’s spent grain by finding alternative uses apart from the current general use as an animal feed. Its possible applications are in human nutrition, as a raw material in biotechnology, energy production, charcoal production, paper manufacture, as a brick component, and adsorbent. In biotechnology brewer’s spent grain could be used as a substrate for cultivation of microorganisms and enzyme production, additive of yeast carrier in beer fermentation, raw material in production of lactic acid, bioethanol, biogas, phenolic acids, xylitol, and pullulan. Some possible applications for brewer’s spent grain are described in this article including pre-treatment conditions (different procedures for polysaccharides, hemicelluloses, and cellulose hydrolysis), working microorganisms, fermentation parameters and obtained yields. The chemical composition of brewer’s spent grain varies according to barley variety, harvesting time, malting and mashing conditions, and a quality and type of unmalted raw material used in beer production. Brewer’s spent grain is lignocellulosic material rich in protein and fibre, which account for approximately 20 and 70% of its composition, respectively.

Pejin Jelena D.; Radosavljevi? Miloš S.; Gruji? Olgica S.; Mojovi? Ljiljana V.; Koci?-Tanackov Sun?ica D.; Nikoli? Svetlana B.; ?uki?-Vukovi? Aleksandra J.

2013-01-01

218

Reviving the carbohydrate economy via multi-product lignocellulose biorefineries.  

UK PubMed Central (United Kingdom)

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

Zhang YH

2008-05-01

219

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

220

Cooperation on spent fuel  

Energy Technology Data Exchange (ETDEWEB)

Incentives for international action on spent fuel storage and the likely limitations are discussed with respect to a study concluded under the aegis of the IAEA by the expert group on International Spent Fuel Management. Public opinion and initiatives which include an information programme to create a better appreciation in society of the concept of risk are also discussed.

Marcus, F. (Nordisk Kontaktorgan for Atomenergispoergsmaal, Risoe (Denmark))

1983-11-01

 
 
 
 
221

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

222

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

UK PubMed Central (United Kingdom)

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.

Wang X; Yomano LP; Lee JY; York SW; Zheng H; Mullinnix MT; Shanmugam KT; Ingram LO

2013-03-01

223

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; Ramesh Babu Manikondu; Carl Johan Franzén; Mohammad J. Taherzadeh

2012-01-01

224

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

UK PubMed Central (United Kingdom)

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.

Westman JO; Manikondu RB; Franzén CJ; Taherzadeh MJ

2012-01-01

225

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.

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

2013-01-01

226

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

UK PubMed Central (United Kingdom)

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.

Jun H; Jiayi C

2012-09-01

227

Selection of the best chemical pretreatment for lignocellulosic substrate Prosopis juliflora.  

UK PubMed Central (United Kingdom)

Pretreatment is a pre-requisite step in bioethanol production from lignocellulosic biomass required to remove lignin and increase the porosity of the substrate for saccharification. In the present study, chemical pretreatment of Prosopis juliflora was performed using alkali (NaOH, KOH, and NH3), reducing agents (Na2S2O4, Na2SO3) and NaClO2 in different concentration ranges at room temperature (30±2 °C) to remove maximum lignin with minimum sugar loss. Further, biphasic acid hydrolysis of the various pretreated substrates was performed at mild temperatures. Considering the amount of holocellulose hydrolyzed and inhibitors released during hydrolysis, best chemical pretreatment was selected. Among all the chemicals investigated, pretreatment with sodium dithionite at concentration of 2% (w/v) removed maximum lignin (80.46±1.35%) with a minimum sugar loss (2.56±0.021%). Subsequent biphasic acid hydrolysis of the sodium dithionite pretreated substrate hydrolyzed 40.09±1.22% of holocellulose and released minimum amount of phenolics (1.04±0.022 g/L) and furans (0.41±0.012 g/L) in the hydrolysate.

Naseeruddin S; Srilekha Yadav K; Sateesh L; Manikyam A; Desai S; Venkateswar Rao L

2013-05-01

228

Selection of the best chemical pretreatment for lignocellulosic substrate Prosopis juliflora.  

Science.gov (United States)

Pretreatment is a pre-requisite step in bioethanol production from lignocellulosic biomass required to remove lignin and increase the porosity of the substrate for saccharification. In the present study, chemical pretreatment of Prosopis juliflora was performed using alkali (NaOH, KOH, and NH3), reducing agents (Na2S2O4, Na2SO3) and NaClO2 in different concentration ranges at room temperature (30±2 °C) to remove maximum lignin with minimum sugar loss. Further, biphasic acid hydrolysis of the various pretreated substrates was performed at mild temperatures. Considering the amount of holocellulose hydrolyzed and inhibitors released during hydrolysis, best chemical pretreatment was selected. Among all the chemicals investigated, pretreatment with sodium dithionite at concentration of 2% (w/v) removed maximum lignin (80.46±1.35%) with a minimum sugar loss (2.56±0.021%). Subsequent biphasic acid hydrolysis of the sodium dithionite pretreated substrate hydrolyzed 40.09±1.22% of holocellulose and released minimum amount of phenolics (1.04±0.022 g/L) and furans (0.41±0.012 g/L) in the hydrolysate. PMID:23567729

Naseeruddin, Shaik; Srilekha Yadav, K; Sateesh, L; Manikyam, Ananth; Desai, Suseelendra; Venkateswar Rao, L

2013-03-16

229

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; Salihan Sias

2011-01-01

230

Renewable liquid fuels from biomass containing lignocellulose; Regenerative Fluessigkraftstoffe aus Lignocellulose haltiger Biomasse  

Energy Technology Data Exchange (ETDEWEB)

The authors review the production processes of liquid fuels from lignocellulose, current research programs and developments. The two principal routes to biofuels are thermochemical processes, like pyrolysis and gasification, and fermentation. One produces pyrolytic oils and gases, the other bio-ethanol. Since energy efficiency of large-scale plants is not yet good enough, small-scale dispersed fuel production in the agricultural areas can be profitable. (uke)

Schieder, D.; Witzelsperger, J. [TU Muenchen (Germany). Lehrstuhl fuer Technologie Biogener Rohstoffe; Prechtl, S. [ATZ Entwicklungszentrum, Sulzbach-Rosenberg (Germany)

2005-07-01

231

Biotechnology for the conversion of lignocellulosics  

Energy Technology Data Exchange (ETDEWEB)

During the last three years most of the research on bioconversion of lignocellulosics has focussed on a process scheme where the substrate is first pretreated, usually by high pressure steam, prior to fractionation into its cellulose, hemicellulose and lignin components. The cellulosic rich fraction is then hydrolyzed enzymatically, followed by fermentation of the liberated sugars to ethanol, while the lignin and pentose sugar rich streams are treated separately. The progress in each of these areas is discussed. Round robin activities between the participant labs were used to provide more uniform methods of quantifying cellulase and xylanase enzyme activities. The various technoeconomic models developed by network members were used to identify probable process schemes and determine technical ''bottlenecks''. (author).

Saddler, J.N. (British Columbia Univ., Vancouver, BC (Canada). Faculty of Forestry)

1992-01-01

232

Tower reactors for bioconversion of lignocellulosic material  

Energy Technology Data Exchange (ETDEWEB)

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

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

1998-01-01

233

Tower reactors for bioconversion of lignocellulosic material  

Energy Technology Data Exchange (ETDEWEB)

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

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

1999-01-01

234

Ultrasonically assisted liquefaction of lignocellulosic materials.  

UK PubMed Central (United Kingdom)

In our research, we have utilized high energy ultrasound for the liquefaction of different lignocellulosic materials, wood wastes in particular. We developed a highly efficient way of transforming this biomass waste into valuable chemicals. It was found, that the reaction yield in all experiments was high and that the reaction times were shortened up to nine times when using the ultrasound process with smaller residual particles and with no influence on the hydroxyl number of the final products. The use of the ultrasound process inhibits the formation of the large molecular structures during the liquefaction from the degradation products, by keeping the reactive segments apart and due to such a short reaction time being used. The short reaction time and subsequent low energy consumption for the liquefaction reaction leads to the creation of the new method for the transformation of the wood waste materials into valuable chemicals.

Kunaver M; Jasiukaityt? E; Cuk N

2012-01-01

235

Functional ionic liquids for hydrolysis of lignocellulose.  

Science.gov (United States)

An efficient system for hydrolysis of lignocellulosic materials to prepare reducing sugar in a series of functional acidic ionic liquids with low synthetic cost and excellent dissolved and catalytic activity was established. High yield of reducing sugar was obtained with the use of 1-H-3-methylimidazolium chloride ([HMIM]Cl). The use of ionic liquid under ultrasound irradiation greatly improved the yield of total reducing sugar. The optimum reaction conditions were as follows: ratio of water/sample was 5 (w/w), ratio of IL/sample was 25 (w/w), 70°C, 120 min and the yield of reducing sugar was up to 53.27 mg from 0.2g of soybean straw and 50.03 mg from 0.2g of corn straw. PMID:23769534

Hu, Xiaomei; Xiao, Yibo; Niu, Kun; Zhao, Yang; Zhang, Bixian; Hu, Baozhong

2013-04-30

236

Superhydrophobic lignocellulosic wood fiber/mineral networks.  

Science.gov (United States)

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

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

2013-09-05

237

Superhydrophobic lignocellulosic wood fiber/mineral networks.  

UK PubMed Central (United Kingdom)

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

Mirvakili MN; Hatzikiriakos SG; Englezos P

2013-09-01

238

(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

239

Tower reactors for bioconversion of lignocellulosic material  

Energy Technology Data Exchange (ETDEWEB)

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

Nguyen, Q.A.

1999-03-30

240

Evolution of organic matter during the mesophilic composting of lignocellulosic winery wastes.  

UK PubMed Central (United Kingdom)

Winery wastes were composted in the laboratory during five months in order to study the composting process of lignocellulosic wastes. In a first experiment, spent grape marc was composted alone, and in a second one, hydrolyzed grape marc, which is the residue generated after the acid hydrolysis of spent grape marc for biotechnological purposes, was composted together with vinification lees. During the composting of spent grape marc, total organic matter did not change, and as total N increased only slightly (from 1.7% to 1.9%), the reduction in the C/N ratio was very low (from 31 to 28). The mixture of hydrolyzed grape marc and lees showed bigger changes, reaching a C/N ratio around 20 from the third month on. Water-soluble organic matter followed the usual trend during composting, showing a progressive decrease in both experiments. Although the mixture of hydrolyzed grape marc and lees presented the highest initial water-soluble carbon concentrations, the final values for both experiments were similar (8.1 g kg(-1) for the spent grape marc, and 9.1 g kg(-1) for the mixture). The analysis of the humification parameters did not allow an adequate description of the composting process, maybe as a consequence of the inherent problems existing with alkaline extractions. The total humic substances, which usually increase during composting as a consequence of the humification process, followed no trend, and they were even reduced with respect to the initial values. Notwithstanding, the fractionation of organic matter into cellulose, hemicellulose and lignin enabled a better monitoring of the waste decomposition. Cellulose and hemicellulose were degraded mainly during the first three months of composting, and the progressive reduction of the cellulose/lignin ratio proved that the main evolution of these wastes took place during the first three months of composting.

Paradelo R; Moldes AB; Barral MT

2013-02-01

 
 
 
 
241

Evolution of organic matter during the mesophilic composting of lignocellulosic winery wastes.  

Science.gov (United States)

Winery wastes were composted in the laboratory during five months in order to study the composting process of lignocellulosic wastes. In a first experiment, spent grape marc was composted alone, and in a second one, hydrolyzed grape marc, which is the residue generated after the acid hydrolysis of spent grape marc for biotechnological purposes, was composted together with vinification lees. During the composting of spent grape marc, total organic matter did not change, and as total N increased only slightly (from 1.7% to 1.9%), the reduction in the C/N ratio was very low (from 31 to 28). The mixture of hydrolyzed grape marc and lees showed bigger changes, reaching a C/N ratio around 20 from the third month on. Water-soluble organic matter followed the usual trend during composting, showing a progressive decrease in both experiments. Although the mixture of hydrolyzed grape marc and lees presented the highest initial water-soluble carbon concentrations, the final values for both experiments were similar (8.1 g kg(-1) for the spent grape marc, and 9.1 g kg(-1) for the mixture). The analysis of the humification parameters did not allow an adequate description of the composting process, maybe as a consequence of the inherent problems existing with alkaline extractions. The total humic substances, which usually increase during composting as a consequence of the humification process, followed no trend, and they were even reduced with respect to the initial values. Notwithstanding, the fractionation of organic matter into cellulose, hemicellulose and lignin enabled a better monitoring of the waste decomposition. Cellulose and hemicellulose were degraded mainly during the first three months of composting, and the progressive reduction of the cellulose/lignin ratio proved that the main evolution of these wastes took place during the first three months of composting. PMID:23274588

Paradelo, Remigio; Moldes, Ana Belén; Barral, María Teresa

2012-12-27

242

Lignocellulose-degrading enzymes from termites and their symbiotic microbiota.  

Science.gov (United States)

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

Ni, Jinfeng; Tokuda, Gaku

2013-04-23

243

Lignocellulose-degrading enzymes from termites and their symbiotic microbiota.  

UK PubMed Central (United Kingdom)

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

Ni J; Tokuda G

2013-11-01

244

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

245

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

246

Spent fuel workshop'2002  

International Nuclear Information System (INIS)

[en] 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.)

2002-01-01

247

Spent fuel management  

International Nuclear Information System (INIS)

The production of nuclear electricity results in the generation of spent fuel that requires safe, secure and efficient management. Appropriate management of the resulting spent fuel is a key issue for the steady and sustainable growth of nuclear energy. Currently about 10,000 tonnes heavy metal (HM) of spent fuel are unloaded every year from nuclear power reactors worldwide, of which 8,500 t HM need to be stored (after accounting for reprocessed fuel). This is the largest continuous source of civil radioactive material generated, and needs to be managed appropriately. Member States have referred to storage periods of 100 years and even beyond, and as storage quantities and durations extend, new challenges arise in the institutional as well as in the technical area. The IAEA gives high priority to safe and effective spent fuel management. As an example of continuing efforts, the 2003 International Conference on Storage of Spent Fuel from Power Reactors gathered 125 participants from 35 member states to exchange information on this important subject. With its large number of Member States, the IAEA is well-positioned to gather and share information useful in addressing Member State priorities. IAEA activities on this topic include plans to produce technical documents as resources for a range of priority topics: spent fuel performance assessment and research, burnup credit applications, cask maintenance, cask loading optimization, long term storage requirements including records maintenance, economics, spent fuel treatment, remote technology, and influence of fuel design on spent fuel storage. In addition to broader topics, the IAEA supports coordinated research projects and technical cooperation projects focused on specific needs

2005-01-01

248

Spent fuel storage chamber  

International Nuclear Information System (INIS)

In a dry spent nuclear fuel storage chamber, an atmosphere in a closed loop comprising storage cell/heated air collecting chamber/cooling air circulation path is filled with gases having a high thermal radiation absorbing performance. Heat released from the spent fuels heats a cylindrical vessel, gases in contact with the peripheral surface thereof and metal blocks constituting the storage cell. Since the gases having highly heat absorbing performance are filled, they are heated by absorbing radiation heat of the spent fuels, to improve the heat dissipation efficiency of the spent fuels. Accordingly, even if the heat generation amount of the spent fuels is great, the temperature elevation can be suppressed since the heat dissipation efficiency of the spent fuels is great due to radiation absorption. In addition, a phenomenon that the temperature of the cylindrical vessel is raised can be suppressed. As a result, fuels or mixed oxide fuels of a high burnup degree having greater heat generation amount compared with usual fuels can be stored safely and economically. (N.H.)

1992-11-13

249

Spent fuel storage chamber  

Energy Technology Data Exchange (ETDEWEB)

In a dry spent nuclear fuel storage chamber, an atmosphere in a closed loop comprising storage cell/heated air collecting chamber/cooling air circulation path is filled with gases having a high thermal radiation absorbing performance. Heat released from the spent fuels heats a cylindrical vessel, gases in contact with the peripheral surface thereof and metal blocks constituting the storage cell. Since the gases having highly heat absorbing performance are filled, they are heated by absorbing radiation heat of the spent fuels, to improve the heat dissipation efficiency of the spent fuels. Accordingly, even if the heat generation amount of the spent fuels is great, the temperature elevation can be suppressed since the heat dissipation efficiency of the spent fuels is great due to radiation absorption. In addition, a phenomenon that the temperature of the cylindrical vessel is raised can be suppressed. As a result, fuels or mixed oxide fuels of a high burnup degree having greater heat generation amount compared with usual fuels can be stored safely and economically. (N.H.).

Futami, Tatsuya; Watanabe, Yoshio.

1994-05-27

250

Use of spent substrate after Pleurotus pulmonarius cultivation for the treatment of chlorothalonil containing wastewater.  

Science.gov (United States)

Lignocellulosic materials are used as substrate for the cultivation of the edible mushroom Pleurotus pulmonarius. After two or three flushes of mushrooms, the spent substrate is discarded although it still has an important enzymatic activity that can be used for several purposes. In this study, we sought to determine the technical feasibility of using spent substrate from P. pulmonarius to degrade chlorothalonil. Reaction mixture was prepared with 6 ml of pesticide aqueous solution (2 mg active ingredient/l) and 3 ml of enzymatic extract obtained from spent P. pulmonarius substrate. The enzymatic reaction (27 °C, pH 7.4) was conducted for 1 h with sampling at 15 min intervals. The effect of storage time and temperature (freezing or refrigerating) of spent substrate and enzymatic extract, respectively, on the activity over chlorothalonil was determined. Freshly obtained spent substrate extract was able to reduce 100% of the initial concentration of chlorothalonil (2 mg/l) after 45 min of reaction. Storage time had a negative effect on the stability of the enzymatic activity: with spent substrate stored for a week, chlorothalonil concentration was reduced in 49.5% after 1 h reaction and with substrate stored for two and three weeks, the degradation efficiency decreased to 9.15% and 0%, respectively. Cooling and freezing the spent substrate extract also had a negative effect on chlorothalonil degradation. PMID:21078538

Juárez, Rosa A Córdova; Dorry, Lilliam L Gordillo; Bello-Mendoza, Ricardo; Sánchez, José E

2011-03-01

251

Use of spent substrate after Pleurotus pulmonarius cultivation for the treatment of chlorothalonil containing wastewater.  

UK PubMed Central (United Kingdom)

Lignocellulosic materials are used as substrate for the cultivation of the edible mushroom Pleurotus pulmonarius. After two or three flushes of mushrooms, the spent substrate is discarded although it still has an important enzymatic activity that can be used for several purposes. In this study, we sought to determine the technical feasibility of using spent substrate from P. pulmonarius to degrade chlorothalonil. Reaction mixture was prepared with 6 ml of pesticide aqueous solution (2 mg active ingredient/l) and 3 ml of enzymatic extract obtained from spent P. pulmonarius substrate. The enzymatic reaction (27 °C, pH 7.4) was conducted for 1 h with sampling at 15 min intervals. The effect of storage time and temperature (freezing or refrigerating) of spent substrate and enzymatic extract, respectively, on the activity over chlorothalonil was determined. Freshly obtained spent substrate extract was able to reduce 100% of the initial concentration of chlorothalonil (2 mg/l) after 45 min of reaction. Storage time had a negative effect on the stability of the enzymatic activity: with spent substrate stored for a week, chlorothalonil concentration was reduced in 49.5% after 1 h reaction and with substrate stored for two and three weeks, the degradation efficiency decreased to 9.15% and 0%, respectively. Cooling and freezing the spent substrate extract also had a negative effect on chlorothalonil degradation.

Juárez RA; Dorry LL; Bello-Mendoza R; Sánchez JE

2011-03-01

252

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; Narayan Chandra Chatterjee

2010-01-01

253

Collagen hydrolysate inhibits zymosan-induced inflammation.  

UK PubMed Central (United Kingdom)

During the past years, evidence accumulated showing that glycine comprises anti-inflammatory activities. These effects occur, at least in part, via the activation of glycine-gated chloride channels (GlyR). Glycine is one of the major structural units of collagen, making up about 30% of the amino acids. This study aims to investigate the anti-inflammatory potential of collagen hydrolysate (CH) using the zymosan-induced ear-skin inflammation mouse model. After oral intake of 12.5, 25 or 50?mg CH the plasma levels of glycine increased in a concentration-dependent manner. CH was able to counteract zymosan-induced ear-skin inflammation locally (ear swelling) as well as systemically (IL-6 production by lipopolysaccharide (LPS)-stimulated whole blood cells). The LPS-stimulated IL-6 production in whole blood correlated positively with the ear swelling response. This correlation was abolished by strychnine (a glycine receptor antagonist), indicating the involvement of GlyR. Collectively, these data show that CH is able to modulate inflammatory responses both locally as well as systemically. This effect might be constituted by inhibiting pro-inflammatory cytokine production via GlyR.

Hartog A; Cozijnsen M; de Vrij G; Garssen J

2013-07-01

254

Collagen hydrolysate inhibits zymosan-induced inflammation.  

Science.gov (United States)

During the past years, evidence accumulated showing that glycine comprises anti-inflammatory activities. These effects occur, at least in part, via the activation of glycine-gated chloride channels (GlyR). Glycine is one of the major structural units of collagen, making up about 30% of the amino acids. This study aims to investigate the anti-inflammatory potential of collagen hydrolysate (CH) using the zymosan-induced ear-skin inflammation mouse model. After oral intake of 12.5, 25 or 50 mg CH the plasma levels of glycine increased in a concentration-dependent manner. CH was able to counteract zymosan-induced ear-skin inflammation locally (ear swelling) as well as systemically (IL-6 production by lipopolysaccharide (LPS)-stimulated whole blood cells). The LPS-stimulated IL-6 production in whole blood correlated positively with the ear swelling response. This correlation was abolished by strychnine (a glycine receptor antagonist), indicating the involvement of GlyR. Collectively, these data show that CH is able to modulate inflammatory responses both locally as well as systemically. This effect might be constituted by inhibiting pro-inflammatory cytokine production via GlyR. PMID:23788175

Hartog, Anita; Cozijnsen, Miranda; de Vrij, Gerrit; Garssen, Johan

2013-06-20

255

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

256

Sustainable Process Design of Lignocellulose based Biofuel  

DEFF Research Database (Denmark)

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

Mikkelsen, Eva

2013-01-01

257

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; Bernard Sodio; Tidjani Amza; Guo-Wei Le; Yong-Hui Shi

2013-01-01

258

Supercritical CO2 pretreatment of lignocellulose enhances enzymatic cellulose hydrolysis.  

Science.gov (United States)

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

Kim, K H; Hong, J

2001-04-01

259

Supercritical CO2 pretreatment of lignocellulose enhances enzymatic cellulose hydrolysis.  

UK PubMed Central (United Kingdom)

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

Kim KH; Hong J

2001-04-01

260

Preprocessing Moist Lignocellulosic Biomass for Biorefinery Feedstocks  

Energy Technology Data Exchange (ETDEWEB)

Biomass preprocessing is one of the primary operations in the feedstock assembly system of a lignocellulosic biorefinery. Preprocessing is generally accomplished using industrial grinders to format biomass materials into a suitable biorefinery feedstock for conversion to ethanol and other bioproducts. Many factors affect machine efficiency and the physical characteristics of preprocessed biomass. For example, moisture content of the biomass as received from the point of production has a significant impact on overall system efficiency and can significantly affect the characteristics (particle size distribution, flowability, storability, etc.) of the size-reduced biomass. Many different grinder configurations are available on the market, each with advantages under specific conditions. Ultimately, the capacity and/or efficiency of the grinding process can be enhanced by selecting the grinder configuration that optimizes grinder performance based on moisture content and screen size. This paper discusses the relationships of biomass moisture with respect to preprocessing system performance and product physical characteristics and compares data obtained on corn stover, switchgrass, and wheat straw as model feedstocks during Vermeer HG 200 grinder testing. During the tests, grinder screen configuration and biomass moisture content were varied and tested to provide a better understanding of their relative impact on machine performance and the resulting feedstock physical characteristics and uniformity relative to each crop tested.

Neal Yancey; Christopher T. Wright; Craig Conner; J. Richard Hess

2009-06-01

 
 
 
 
261

Hyperthermophilic endoglucanase for in planta lignocellulose conversion  

Directory of Open Access Journals (Sweden)

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

Klose Holger; Röder Juliane; Girfoglio Michele; Fischer Rainer; Commandeur Ulrich

2012-01-01

262

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

263

Hydrolysis of lignocelluloses by penicillium funiculosum cellulase  

Energy Technology Data Exchange (ETDEWEB)

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

Mishra, C.; Rao, M.; Seeta, R.; Srinivasan, M.C.; Deshpande, V.

1984-04-01

264

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...

Landaeta, R.; Aroca, G.; Acevedo, F.; Teixeira, J. A.; Mussatto, Solange I.

265

Improved lignocellulose conversion to biofuels with thermophilic bacteria and thermostable enzymes  

Science.gov (United States)

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

266

Breeding of lignocellulose-direct fermenting yeast. Lignocellulose chokusetsu hakkokin no ikushu  

Energy Technology Data Exchange (ETDEWEB)

Technologies to convert lignocellulose into glucose by enzyme, such as cellulase, and produce ethanol by fermenting glucose by yeast, are already known. However, these technologies have not been put in practical use, because of excessively high cost of ethanol. In order to reduce the production cost of ethanol, breeding of lignocellulose-direct fermenting yeast was researched. The purpose of the researches was to breed such yeast by genetic engineering that the yeast itself produced cellulase enzyme and fermented directly cellulose or hemicellulose. In the case of cellulose, genes of cellulase enzyme were cloned in colibacillus, and transplanted into yeast. The genes were manifested themselves in the yeast and then produced enzyme. The enzyme was secreted out of cells of the yeast, changed cellulose into low molecular weight, which was taken into the cells and was converted into ethanol. The research results by this way are reported, such as breeding of xylan-direct fermenting yeast, xylose fermenting yeast, cellulose-direct fermenting yeast, and cellobiose fermenting yeast. 20 refs., 6 figs.

Okada, H. (Kumamoto Inst. of Technology, Kumamoto (Japan))

1991-05-05

267

Role of protein and hydrolysates before exercise.  

UK PubMed Central (United Kingdom)

Adaptations to exercise training are determined by the response of metabolic and molecular mechanisms that determine changes in proteins. The type, intensity, and duration of exercise, as well as nutrition, determine these responses. The importance of protein, in the form of intact proteins, hydrolysates, or free amino acids, for exercise adaptations is widely recognized. Exercise along with protein intake results in accumulation of proteins that influence training adaptations. The total amount of protein necessary to optimize adaptations is less important than the type of protein, timing of protein intake, and the other nutrients ingested concurrently with the protein. Acute metabolic studies offer an important tool to study the responses of protein balance to various exercise and nutritional interventions. Recent studies suggest that ingestion of free amino acids plus carbohydrates before exercise results in a superior anabolic response to exercise than if ingested after exercise. However, the difference between pre-and postexercise ingestion of intact proteins is not apparent. Thus, the anabolic response to exercise plus protein ingestion seems to be determined by the interaction of timing of nutrient intake in relation to exercise and the nutrients ingested. More research is necessary to delineate the optimal combination of nutrients and timing for various types of training adaptations. Protein and amino acid intake have long been deemed important for athletes and exercising individuals. Olympic athletes, from the legendary Milo to many in the 1936 Berlin games, reportedly consumed large amounts of protein. Modern athletes may consume slightly less than these historical figures, yet protein is deemed extremely important by most. Protein is important as a source of amino acids for recovery from exercise and repair of damaged tissues, as well as for adaptations to exercise training, such as muscle hypertrophy and mitochondrial biogenesis.

Tipton KD

2007-08-01

268

Enhancement of enzymic susceptibility of lignocellulosic wastes by microwave irradiation  

Energy Technology Data Exchange (ETDEWEB)

Microwave irradiation in the presence of water provides a new pretreatment method for enzymic saccharification of lignocellulosic wastes. When 3 representative lignocellulosic wastes, sugar cane bagasse, rice straw, and rice hulls, were treated with microwave energy, acidity and furfural production increased with increasing temperature and reached 0.30-1.13 meq and 0.07-1.63% respectively, at 227 degrees. No substantial change in crystallinity of the cellulose was detected by short heating (more than 8 min) below 230 degrees. Hemicellulose and lignin, however, suffered acid-catalyzed autohydrolysis. The reducing sugar production started at 180-190 degrees and showed a maximum (11-27%) at approximately 230 degrees, and the amount of the water-soluble components and degraded lignin extractable with 90% dioxane or MeOH were prominent above 180 degrees but showed no maximum up to 240 degrees. Aqueous dioxane removed 1.3-2.5 times more lignin than MeOH above 220 degrees. The enzymic susceptibility of all the lignocellulosic wastes were markedly improved by microwave pretreatment above 160 degrees and showed a maximum at 223-228 degrees, independent of their source. The maximal percentage of reducing sugars was 77-84% of the polysaccharide present in the original lignocellulosic wastes. The increase in available surface of cellulose due to degradation of encrusting lignin and hemicellulose is suggested to be a rate-determining factor for enzymic saccharification of cellulose in lignocellulosic wastes because of the stability of crystallinity of cellulose toward microwave irradiation.

Azuma, J.; Tanaka, F.; Koshijima, T.

1984-01-01

269

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

270

Spent fuel storage racks  

International Nuclear Information System (INIS)

Purpose: To decrease a spent fuel storage area occupied in a storage pool by increasing the storage density of the spent fuel, thereby enabling semi-permanent storage. Constitution: A framework of a spent fuel storage racks is made of stainless steel; and cells for holding fuel rod assemblies are formed by fitting, in its wall surface, ceramic tiles produced by sintering a mixture of such medium materials as Al2O3, SiO2, and ZrO2 and such elements as Eu, Hf, Gd, Sm, Co and Rh used as neutron absorbers which emit gamma rays in the process of reaction to neutrons. The most desirable neutron absorber to be used is Hf which has a high neutron absorbing capacity and a long half-life, is capable of keeping on absorbing neutrons even after neutron absorption, and makes (n,?) neutron absorption reaction, emitting gamma rays without accompanying any change of the ceramic tiles with time. (Sekiya, K.).

1984-12-27

271

Spent fuel pyroprocessing demonstration  

International Nuclear Information System (INIS)

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

1995-01-01

272

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; Jian Tang; Xiao-Hong Gu

2007-01-01

273

Spent nuclear fuel transportation  

International Nuclear Information System (INIS)

[en] Conditions applicable to transport casks and to consignments containing fissile materials are given. Radiation level limits, highest permissible contaminations, and limits for mandatory decontamination are specified. Each package, vehicle or wagon must be provided with a prescribed label. A list of the required transport documents is presented. The regulatory authorities must be notified about transports. Radiological safety requirements are given. Each spent fuel transport must be licensed by the authorized body. Safety of spent fuel transportation is fully secured in the Czech Republic. (J.B.)

1995-01-01

274

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

275

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

Energy Technology Data Exchange (ETDEWEB)

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 0.39- 0.42 g/g-sugars consumed. Xylose was nearly completely utilized (89-98%) 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. (orig.)

Georgieva, T.I.; Ahring, B.K. [Technical Univ. of Denmark, Lyngby (Denmark). BioScience and Technology Group

2007-11-15

276

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 0.39–0.42 g/g-sugars consumed. Xylose was nearly completely utilized (89–98%) 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

277

PRETREATMENT TECHNOLOGIES IN BIOETHANOL PRODUCTION FROM LIGNOCELLULOSIC BIOMASS  

Directory of Open Access Journals (Sweden)

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

Vanja Januši?; Duška ?uri?; Tajana Kri?ka; Neven Vo?a; Ana Matin

2008-01-01

278

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

2008-01-01

279

Enzymatic hydrolysis of spent coffee ground.  

UK PubMed Central (United Kingdom)

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.

Jooste T; García-Aparicio MP; Brienzo M; van Zyl WH; Görgens JF

2013-04-01

280

Bionic enzymatic hydrolysate for centipede and application thereof  

UK PubMed Central (United Kingdom)

The invention discloses bionic enzymatic hydrolysate for centipedes and application thereof, and belongs to the field of Chinese medicaments. The invention adopts the technical scheme that: a bionic enzymolysis method is adopted the centipedes are taken and after water is added in the centipedes so as to form homogenate, under proper conditions, the heat preserving enzymolysis is carried out firstly by pepsin, and then the heat preserving enzymolysis is carried out by pancreatin or trypsase. The obtained enzymatic hydrolysate is prepared into preparations according to different preparation requirements. The bionic enzymatic hydrolysate has the excellent effects in aspects of treating cancer, cardiovascular and cerebrovascular diseases, hepatitis, chronic nephritis, rheumatic arthropathy,sciatic nerve diseases, and various dermatosis pruritus symptoms.

QINQING LI; JIAYU ZHANG

 
 
 
 
281

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

282

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

UK PubMed Central (United Kingdom)

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

Meinita MD; Hong YK; Jeong GT

2012-01-01

283

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

Science.gov (United States)

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

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

2011-09-10

284

Bitter taste inhibiting agents for whey protein hydrolysate and whey protein hydrolysate beverages.  

UK PubMed Central (United Kingdom)

Whey protein hydrolysates (WPH) are known for bioactivity and functionality, but WPH also have a distinct bitter taste. Identification of effective bitter taste inhibiting agents for WPH would broaden the use of this ingredient. The objective of this study was to evaluate the effectiveness of 24 documented bitter taste inhibitors for WPH. Two spray-dried WPH with different levels of hydrolysis (DH) were evaluated with each potential inhibitor. Quinine hydrochloride (quinine) was presented as a control with each WPH. Percent bitter taste inhibition was reported relative to quinine bitterness. Effective bitter taste inhibitors were subsequently evaluated in WPH beverages with vanilla and chocolate flavoring followed by descriptive analysis. The compounds evaluated did not inhibit bitter taste of quinine and the 2 WPH in a similar manner (P < 0.05). Effective bitter taste inhibitors (P < 0.05) of both WPH were sucralose, fructose, sucrose, adenosine 5' monophosphate (5'AMP), adenosine 5'monophosphate disodium (5'AMP Na(2) ), sodium acetate, monosodium glutamate, and sodium gluconate. Sodium chloride inhibited bitter taste of WPH with high DH but not WPH with low DH. Amino acids (l-Lysine, l-arginine) inhibited bitter taste of quinine but not WPH. All effective inhibitors in rehydrated WPH were also effective in the beverage applications. Sweeteners (fructose, sucralose, and sucrose) enhanced vanilla and chocolate flavors in beverages. Most salts and a nucleotide, while effective for bitter taste inhibition, suppressed vanilla and chocolate flavors and potentiated other flavors (that is, sour aromatic), and basic tastes (salty, sour). PRACTICAL APPLICATIONS: The bitter taste of whey protein hydrolysates (WPH) limits their use as ingredients. This study identified effective bitter taste inhibitors of WPH with different peptide composition and provides insights for effective bitter inhibitors for product applications with WPH.

Leksrisompong P; Gerard P; Lopetcharat K; Drake M

2012-08-01

285

Reprocessing of spent plasma  

International Nuclear Information System (INIS)

This invention relates to a process for removing helium and other impurities from a mixture containing deuterium and tritium, a deuterium/tritium mixture when purified in accordance with such a process and, more particularly, to a process for the reprocessing of spent plasma removed from a thermofusion reactor. (U.K.)

1981-01-01

286

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; Hasina Banu; M. Motiur Rahman; Firaza Akhter; M. Shamsul Haque

2001-01-01

287

Concentration of lignocellulosic hydrolyzates by solar membrane distillation.  

UK PubMed Central (United Kingdom)

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.

Zhang L; Wang Y; Cheng LH; Xu X; Chen H

2012-11-01

288

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

2012-07-27

289

A PROCESS FOR PRODUCTION OF ETHANOL FROM LIGNOCELLULOSIC MATERIAL  

UK PubMed Central (United Kingdom)

This invention relates to a process for production of ethanol from lignocellulosic material. Lignocellulosic material treated with dicarboxylic acid, preferably with oxalic acid, separating hemicellulosic fraction to ferment pentose sugar. The lignin is dissolve in alkali, preferably with NaOH, separating cellulose fraction for further enzymatic treatment with one or more than one cellulytic enzymes capable of hydrolyzing cellulose. Enzyme hydrolyasate further subjected to fermentation in presence of ethanol producing yeast, preferably Saccharomyces cerevisiae. The fermented broth further subjected to distillation followed by dehydration to yield ethanol.

INAMDAR SHASHANK NARAYAN; SONTI VENKATA RAMAKRISHNA; RAO RAVIKUMAR; KULKARNI MILIND SHRIKANT; RAO PRASAD; BABU MOHAN; JOSHI SATYENDRA WAMAN; LOKARE ANILKUMAR SUBHASH; GOKHALE PRASHANT PRAKASH; SHETE ASHVINI MONISH; MUKHARJEE GUNJAN NABAKUMAR

290

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; Maria V. MORAR

2009-01-01

291

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; Donohoe Bryon S; Vinzant Todd B; Ciesielski Peter N; Wang Wei; Gedvilas Lynn M; Zeng Yining; Johnson David K; Ding Shi-You; Himmel Michael E; Tucker Melvin P

2011-01-01

292

Gas chromatographic determination of hydroxyproline in urine hydrolysates.  

Science.gov (United States)

A simple and specific method for the determination of hydroxyproline in urine hydrolysates has been described. Hydroxyproline was converted into its N-isobutyloxycarbonyl methyl ester derivative without elaborate cleanup, which was analyzed by gas chromatography. Hydroxyproline was clearly separated from other urinary constituents on a 0.60% FFAP on dimethyldichlorosilane-treated Gas-Chrom P column. Kainic acid was used as the most convenient internal standard available. The relative standard deviations of peak height ratios were 1.15--2.51% at the 10--150 microgram levels. Percent recoveries of hydroxyproline added to urine hydrolysates ranged from 98.8 to 107.3%. PMID:699324

Makita, M; Yamamoto, S; Tsudaka, Y

1978-09-01

293

Gas chromatographic determination of hydroxyproline in urine hydrolysates.  

UK PubMed Central (United Kingdom)

A simple and specific method for the determination of hydroxyproline in urine hydrolysates has been described. Hydroxyproline was converted into its N-isobutyloxycarbonyl methyl ester derivative without elaborate cleanup, which was analyzed by gas chromatography. Hydroxyproline was clearly separated from other urinary constituents on a 0.60% FFAP on dimethyldichlorosilane-treated Gas-Chrom P column. Kainic acid was used as the most convenient internal standard available. The relative standard deviations of peak height ratios were 1.15--2.51% at the 10--150 microgram levels. Percent recoveries of hydroxyproline added to urine hydrolysates ranged from 98.8 to 107.3%.

Makita M; Yamamoto S; Tsudaka Y

1978-09-01

294

Biological activities of lignin hydrolysate-related compounds.  

UK PubMed Central (United Kingdom)

Lignin hydrolysates contain many different chemical species, including ferulic acid, coumaric acid, vanillic acid, vanillin, syringaldehyde and furfural. From the perspective of biofuels, these compounds are problematic and can cause downstream loss of product if not removed prior to beginning the fermentative process. In contrast, a search for these compounds within the literature turns up many papers where the same compounds have beneficial properties pertaining to human health, including as antioxidants and in cancer prevention, or are involved in bacterial cell-to-cell signaling. Consequently, this article reviews the dual nature of these and other compounds found in lignin hydrolysates, highlighting both their detrimental and beneficial activities.

Lee S; Monnappa AK; Mitchell RJ

2012-05-01

295

USE OF A RICE PROTEIN HYDROLYSATE AS PIGMENTING ACTIVE PRINCIPLE  

UK PubMed Central (United Kingdom)

The present invention concerns the use of a rice protein hydrolysate in order to pigment the skin and skin appendages. Thus, it is possible to intensify the normal pigmentation of the skin without sunlight. Preferred areas of applications are repigmentation of white patches of the skin, repigmentation of white patches of the skin as a consequence of pityriasis or due to the use of dermocorticoids; acceleration and intensification of the tanning process, stimulation of the constitutive photoprotection and improvement of the phototype, prevention of skin photocarcinogenesis. Advantageously, the rice protein hydrolysate comprises peptides of which at least 50% have a molecular mass in the range of between 300 and 3,500 Da.

MSIKA PHILIPPE; NAAIMI DALALE

296

USE OF A RICE PROTEIN HYDROLYSATE AS PIGMENTING ACTIVE PRINCIPLE.  

UK PubMed Central (United Kingdom)

The present invention concerns the use of a rice protein hydrolysate in order to pigment the skin and skin appendages. Thus, it is possible to intensify the normal pigmentation of the skin without sunlight. Preferred areas of applications are repigmentation of white patches of the skin, repigmentation of white patches of the skin as a consequence of pityriasis or due to the use of dermocorticoids acceleration and intensification of the tanning process, stimulation of the constitutive photoprotection and improvement of the phototype, prevention of skin photocarcinogenesis. Advantageously, the rice protein hydrolysate comprises peptides of which at least 50 % have a molecular mass in the range of between 300 and 3,500 Da.

MSIKA PHILIPPE; NAAIMI DALALE

297

Fish waste protein hydrolysate used as spirulina growth regulator  

UK PubMed Central (United Kingdom)

The invention discloses fish waste protein hydrolysate used as a spirulina growth regulator. Fish waste is cleaned and pulped, and is subjected to enzymolysis by protease, so that the fish waste protein is degraded into mixed liquor of polypeptides, oligopeptides and free amino acids with different molecular weights and the mixed liquor is subjected to centrifugation and filtration for removing residue and fish oil so as to form the protein hydrolysate. 0.05 to 0.5 percent (volume ratio) of regulator is added on the basis of the traditional Zarrouk culture medium to promote the growth of spirulina, and the biomass can be improved by 15 to 40 percent.

PENGZHI HONG; PING YANG; SHAOKUI ZENG; CHUNXIA ZHOU

298

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

Science.gov (United States)

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

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

2013-04-01

299

Improved lignocellulose conversion to biofuels with thermophilic bacteria and thermostable enzymes.  

UK PubMed Central (United Kingdom)

Second-generation feedstock, especially nonfood lignocellulosic biomass is a potential source for biofuel production. Cost-intensive physical, chemical, biological pretreatment operations and slow enzymatic hydrolysis make the overall process of lignocellulosic conversion into biofuels less economical than available fossil fuels. Lignocellulose conversions carried out at ? 50 °C have several limitations. Therefore, this review focuses on the importance of thermophilic bacteria and thermostable enzymes to overcome the limitations of existing lignocellulosic biomass conversion processes. The influence of high temperatures on various existing lignocellulose conversion processes and those that are under development, including separate hydrolysis and fermentation, simultaneous saccharification and fermentation, and extremophilic consolidated bioprocess are also discussed.

Bhalla A; Bansal N; Kumar S; Bischoff KM; Sani RK

2013-01-01

300

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

 
 
 
 
301

Lignocellulose degradation and crude protein formation by three ligninolytic Streptomyces strains  

Energy Technology Data Exchange (ETDEWEB)

Streptomyces strains (11A, 21B and 31C) were grown on guinea grass lignocellulose and their ability to decompose lignocellulose was monitored. All three Streptomyces strains caused lignocellulose weight losses ranging from 27 to 34%. The three Streptomyces strains were also found to metabolize between 27 and 40% of the lignin component and 22-29% of the carbohydrate component of lignocellulose over the 12 week incubation period. Crude protein increases of degraded guinea grass lignocellulose were between 10.1 and 14.5% over the same period.

Njoku, C.C.; Antai, S.P.

1987-01-01

302

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

303

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

Scientific Electronic Library Online (English)

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

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

2011-09-01

304

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

International Nuclear Information System (INIS)

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

1986-01-01

305

Screening of Fungi Capable of Degrading Lignocellulose from Plantation Forests  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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 Nort...

Djarwanto; S. Tachibana

306

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

307

The IBUS process - lignocellulosic bioethanol close to a commercial reality  

Energy Technology Data Exchange (ETDEWEB)

Integrated Biomass Utilization System (IBUS) is a new process for converting lignocellulosic waste biomass to bioethanol. Inbicon A/S has developed the IBUS process in a large-scale process development unit. This plant features new continuous and energy-efficient technology developed for pretreatment and liquefaction of lignocellulosic biomass and has now been operated and optimized for four years with promising results. In the IBUS process, biomass is converted using steam and enzymes only. The process is energy efficient due to very high dry matter content in all process steps and by integration with a power plant. Cellulose is converted to bioethanol and lignin to a high-quality solid biofuel which supply the process energy as well as a surplus of heat and power. Hemicellulose is used as feed molasses but in the future it could also be used for additional ethanol production or other valuable products. Feasibility studies of the IBUS process show that the production price for lignocellulosic bioethanol is close to the world market price for fuel ethanol. There is still room for optimization - and lignocellulosic bioethanol is most likely a commercial alternative to fossil transport fuels before 2012. (Abstract Copyright [2008], Wiley Periodicals, Inc.)

Larsen, J.; Oestergaard Petersen, M.; Thirup, L.; Wen Li, H.; Krogh Iversen, F. [Inbicon A/S, Fredericia (Denmark)

2008-05-15

308

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

309

PRETREATMENT OF LIGNOCELLULOSIC BIOMASS THROUGH REMOVAL OF INHIBITORY COMPOUNDS  

UK PubMed Central (United Kingdom)

A process for the pretreatment of lignocellulosic biomass is disclosed. The process is intended for use in connection with biomass to ethanol processes and is directed in particular to an economical removal of inhibitory compounds generated in biomass pretreatment, which are inhibitory to downstream hydrolysis and fermentation steps. The process includes the steps of heating the lignocellulosic biomass with steam to a preselected temperature, at a preselected pressure and for a preselected time to hydrolyze and solubilize hemicelluloses in the biomass explosively decomposing the biomass into fibers, and extracting from the resulting reaction mixture a liquefied portion of the lignocellulosic biomass before or after explosive decomposition. The liquefied portion is extracted to remove compounds from the lignocellulosic biomass which are inhibitory to enzymatic cellulose hydrolysis and sugar fermentation to ethanol. For improved efficiency and economy, the inhibitory compounds are not completely removed. Furthermore, xylose has been found to be a good indicator compound for the general level of inhibitory compounds in the reaction mixture and the extraction step is therefore controlled on the basis of the xylose content in the reaction mixture. In particular, the extracting step is discontinued once a dry matter (dm) content of xylose, as monomer or oligomer, in the reaction mixture of 4% to 8% (w/w dm) is achieved. This most economically balances the practical need for inhibitory compound removal with the economical need to control and preferably minimize the costs of the overall ethanol production process.

DOTTORI FRANK A; BENSON ROBERT ASHLEY COOPER; BENECH REGIS-OLIVIER

310

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

UK PubMed Central (United Kingdom)

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.

Wu H; Zhang PY; Guo JB; Wu YJ

2013-02-01

311

Characterization of casein hydrolysates derived from enzymatic hydrolysis  

Science.gov (United States)

Background Casein is the main proteinaceous component of milk and has made us interest due to its wide applications in the food, drug, and cosmetic industries as well as to its importance as an investigation material for elucidating essential questions regarding the protein chemistry. Enzymatic hydrolysis is an important method commonly used in the modification of protein structure in order to enhance the functional properties of proteins. The relationship between enzymatic hydrolysis and structure change of casein need to make more study. Results During hydrolysis, degree of hydrolysis in the casein hydrolysates increased rapidly in the initial 20 minutes, reached a plateau after 45 minutes, and then kept relative constant for the rest of the hydrolysis. The relative percentage of the released peptides with molecular weight of over 50 kD significantly decreased with hydrolyzation, while those with MW of 30–50 kD and below 20 kD increased significantly. The contents of a-helix and ?-turn in the hydrolysates increased compared to the original casein. Moreover, the molecular flexibilities of the casein hydrolysates, estimated by the ratio of ?-helix to ?-structure, were lower than that of original casein protein. Conclusions The significant changes in molecular weight distribution and structure characteristics of casein hydrolysates were found compared to the control sample. This change should be the basis of enhancement of functional properties.

2013-01-01

312

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.

2012-01-01

313

PLANT EXTRACT HYDROLYSATES AND ANTIBACTERIAL PRODUCT CONTAINING THE SAME  

UK PubMed Central (United Kingdom)

The invention relates to a hydrolysate from at least one extract of at least one plant material selected from Equiseti herba (horsetail herb), Juglandis folium (walnut leaf), Millefolii herba (yarrow), Quercus cortex (oak bark), Taraxaci herba (dandelion root herb), Althaeae radix (marshmallow root), Matricariae flos (or Flos chamomillae (chamomile flower)), Centaurium erythraea (centaury

POPP MICHAEL

314

Characterization of casein hydrolysates derived from enzymatic hydrolysis.  

UK PubMed Central (United Kingdom)

BACKGROUND: Casein is the main proteinaceous component of milk and has made us interest due to its wide applications in the food, drug, and cosmetic industries as well as to its importance as an investigation material for elucidating essential questions regarding the protein chemistry. Enzymatic hydrolysis is an important method commonly used in the modification of protein structure in order to enhance the functional properties of proteins. The relationship between enzymatic hydrolysis and structure change of casein need to make more study. RESULTS: During hydrolysis, degree of hydrolysis in the casein hydrolysates increased rapidly in the initial 20 minutes, reached a plateau after 45 minutes, and then kept relative constant for the rest of the hydrolysis. The relative percentage of the released peptides with molecular weight of over 50 kD significantly decreased with hydrolyzation, while those with MW of 30-50 kD and below 20 kD increased significantly. The contents of a-helix and ?-turn in the hydrolysates increased compared to the original casein. Moreover, the molecular flexibilities of the casein hydrolysates, estimated by the ratio of ?-helix to ?-structure, were lower than that of original casein protein. CONCLUSIONS: The significant changes in molecular weight distribution and structure characteristics of casein hydrolysates were found compared to the control sample. This change should be the basis of enhancement of functional properties.

Wang J; Su Y; Jia F; Jin H

2013-01-01

315

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; Oana Emilia CONSTANTIN

2012-01-01

316

Encapsulating spent nuclear fuel  

International Nuclear Information System (INIS)

[en] 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

317

Solidification of spent extractant  

International Nuclear Information System (INIS)

For high-level wastes processing the extractants on the base of chlorinated cobalt dicarbollyde (CCD) are used. As a solvent of CCD thrifluoromethylphenylsylphone (FS-13) and nitrobenzotrifluoride (F3) are used. The structure formula and basic characteristics of these substances are given. The most efficient way of transformation of FS-13 and F3 into solid substances is their condensation with formaldehyde and phenol. There were made some researches in the field of polymer synthesis on the basis of these substances. As a result of condensation of phenol, formaldehyde and FS-13 (F3) in acid medium during 4 hours at temperature higher than 150 grad C, the black color hard sediment was produced. The received co-polymer does not dissolve in water, organic solvents, water solutions of acids and alkalis. In analogy with this method, hard insoluble substances on the basis of waste extractant, the main part of which was F3 or FS-13, were obtained. As a result of this method of transformation of spent extractant into solid substance, there appears plastic with presented characteristics. Outwardly this plastic, obtained from spent extractant, looks as black-and-brown color glassy mass. It does not solute and swell in organic solvents, in water solutions of acids and alkalis as well. Being poured by concentrated alkali solution, it disintegrated into smaller pieces, but it did not dissolve. The obtained plastic is notable for high thermostability. The marked decomposition begins at the temperature higher than 250 grad C and up to 400 grad C it goes without exo-thermal effects. According to preliminary calculation 1,4 liter of plastic can be obtained from 1 liter of spent extractant. Thus, the producing of plastic from spent extractant is rather simple and economical way of converting liquid organic wastes into solid form. (authors)

2003-01-01

318

Ethanol production from sugarcane bagasse hydrolysate using Pichia stipitis.  

UK PubMed Central (United Kingdom)

The objective of this study was to evaluate the ethanol production from the sugars contained in the sugarcane bagasse hemicellulosic hydrolysate with the yeast Pichia stipitis DSM 3651. The fermentations were carried out in 250-mL Erlenmeyers with 100 mL of medium incubated at 200 rpm and 30 degrees C for 120 h. The medium was composed by raw (non-detoxified) hydrolysate or by hydrolysates detoxified by pH alteration followed by active charcoal adsorption or by adsorption into ion-exchange resins, all of them supplemented with yeast extract (3 g/L), malt extract (3 g/L), and peptone (5 g/L). The initial concentration of cells was 3 g/L. According to the results, the detoxification procedures removed inhibitory compounds from the hemicellulosic hydrolysate and, thus, improved the bioconversion of the sugars into ethanol. The fermentation using the non-detoxified hydrolysate led to 4.9 g/L ethanol in 120 h, with a yield of 0.20 g/g and a productivity of 0.04 g L(-1) h(-1). The detoxification by pH alteration and active charcoal adsorption led to 6.1 g/L ethanol in 48 h, with a yield of 0.30 g/g and a productivity of 0.13 g L(-1) h(-1). The detoxification by adsorption into ion-exchange resins, in turn, provided 7.5 g/L ethanol in 48 h, with a yield of 0.30 g/g and a productivity of 0.16 g L(-1) h(-1).

Canilha L; Carvalho W; Felipe Md; Silva JB; Giulietti M

2010-05-01

319

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

320

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

Science.gov (United States)

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

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

2012-08-15

 
 
 
 
321

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

UK PubMed Central (United Kingdom)

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

Forghani B; Ebrahimpour A; Bakar J; Abdul Hamid A; Hassan Z; Saari N

2012-01-01

322

HPLC preparation of fish waste hydrolysate fractions. Effect on guinea pig ileum and ACE activity.  

Science.gov (United States)

The effect of RP-HPLC-purified fractions of fish waste hydrolysates issued from three fish industries was tested on guinea pig ileum in order to examine the presence of opioid molecules. The evaluation of anti-hypertensive activities of whole hydrolysates and fractions were also tested, monitoring the ability of the fraction to inhibit the activity of angiotensin I-converting enzyme involved in hypertension regulation. Sardine autolysate and cod head hydrolysate powder (50 microg) were able to inhibit near 30% of ACE activity, whereas 50 microg of shrimp hydrolysate allows the inhibition of 57% of ACE activity. HPLC fractionation of cod head hydrolysate and sardine autolysate was necessary to evidence biological activity, whereas HPLC separation of shrimp hydrolysate exhibited low biological activity fractions. Further studies are necessary to characterise bioactive molecules from cod head alcalase hydrolysate and from sardine autolysate. PMID:11934078

Bordenave, Stephanie; Fruitier, Ingrid; Ballandier, Isabelle; Sannier, Frederic; Gildberg, Asbjorn; Batista, Irineu; Piot, Jean-Marie

2002-02-01

323

HPLC preparation of fish waste hydrolysate fractions. Effect on guinea pig ileum and ACE activity.  

UK PubMed Central (United Kingdom)

The effect of RP-HPLC-purified fractions of fish waste hydrolysates issued from three fish industries was tested on guinea pig ileum in order to examine the presence of opioid molecules. The evaluation of anti-hypertensive activities of whole hydrolysates and fractions were also tested, monitoring the ability of the fraction to inhibit the activity of angiotensin I-converting enzyme involved in hypertension regulation. Sardine autolysate and cod head hydrolysate powder (50 microg) were able to inhibit near 30% of ACE activity, whereas 50 microg of shrimp hydrolysate allows the inhibition of 57% of ACE activity. HPLC fractionation of cod head hydrolysate and sardine autolysate was necessary to evidence biological activity, whereas HPLC separation of shrimp hydrolysate exhibited low biological activity fractions. Further studies are necessary to characterise bioactive molecules from cod head alcalase hydrolysate and from sardine autolysate.

Bordenave S; Fruitier I; Ballandier I; Sannier F; Gildberg A; Batista I; Piot JM

2002-02-01

324

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.; Bo?arov-Stan?i? Aleksandra S.; Milenkovi? Ivanka M.; Štrbac Snežana S.; Adamovi? Ivana

2007-01-01

325

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

326

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

327

Dry fractionation process as an important step in current and future lignocellulose biorefineries: a review.  

UK PubMed Central (United Kingdom)

The use of lignocellulosic biomass is promising for biofuels and materials and new technologies for the conversion need to be developed. However, the inherent properties of native lignocellulosic materials make them resistant to enzymatic and chemical degradation. Lignocellulosic biomass requires being pretreated to change the physical and chemical properties of lignocellulosic matrix in order to increase cell wall polymers accessibility and bioavailability. Mechanical size reduction may be chemical free intensive operation thanks to decreasing particles size and cellulose crystallinity, and increasing accessible surface area. Changes in these parameters improve the digestibility and the bioconversion of lignocellulosic biomass. However, mechanical size reduction requires cost-effective approaches from an energy input point of view. Therefore, the energy consumption in relation to physicochemical properties of lignocellulosic biomass was discussed. Even more, chemical treatments combined with physicochemical size reduction approaches are proposed to reduce energy consumption in this review.

Barakat A; de Vries H; Rouau X

2013-04-01

328

Use of Protein Hydrolysates in Industrial Starter Culture Fermentations  

Science.gov (United States)

Lactic acid bacteria (LAB) have been used as starter cultures for fermenting foods long before the importance of microorganisms were recognized. The most important group of LAB are the lactococci, lactobacilli, streptococci, and pediococci. Additionally, bifidobacteria have been included as a probiotic, providing added value to the product. Since the genera involved are so diverse, the nutritional requirements (energy, carbon and nitrogen sources) differ significantly between and within species. Designing an optimum fermentation medium for production of active and vigorous LAB starter cultures and probiotics requires selecting the right raw ingredients, especially protein hydrolysates that can provide adequate nutrients for growth and viability. This chapter attempts to describe the application of various commercial protein hydrolysates used for production of dairy and meat starter cultures, with special emphasis on meeting the nitrogen requirements of industrially important LAB species.

Ummadi, Madhavi (Soni); Curic-Bawden, Mirjana

329

Hydrolyses of calcium phosphates-allografts composite in physiological solutions.  

Science.gov (United States)

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

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

2006-04-01

330

Canonical correlations between chemical and energetic characteristics of lignocellulosic wastes  

Directory of Open Access Journals (Sweden)

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

Thiago de Paula Protásio; Gustavo Henrique Denzin Tonoli; Mário Guimarães Júnior; Lina Bufalino; Allan Motta Couto; Paulo Fernando Trugilho

2012-01-01

331

Application of rumen microorganisms for anaerobic bioconversion of lignocellulosic biomass.  

UK PubMed Central (United Kingdom)

Rumen in the mammalian animals is a natural cellulose-degrading system and the microorganisms inside have been found to be able to effectively digest lignocellulosic biomass. Furthermore, methane or volatile fatty acids, which could be further converted to other biofuels, are the two major products in such a system. This paper offers an overview of recent development in the application of rumen microorganisms for lignocellulosic biomass conversion. Application of recent molecular tools in the analysis of rumen microbial community, progress in the development of artificial rumen reactors, the latest research results about characterizing rumen-dominated anaerobic digestion process and energy products are summarized. Also, the potential application of such a rumen-dominated process is discussed.

Yue ZB; Li WW; Yu HQ

2013-01-01

332

Modeling progression of fluorescent probes in bioinspired lignocellulosic assemblies.  

UK PubMed Central (United Kingdom)

Progression of enzymes in lignocellulosic biomass is a crucial parameter in biorefinery processes, and it appears to be one of the limiting factors in optimizing lignocellulose degradation. In order to assay the importance of the chemical and structural features of the substrate matrix on enzyme mobility, we have designed bioinspired model assemblies of secondary plant cell walls, which have been used to measure the mobility of fluorescent probes while modifying different parameters (probe size, water content, polysaccharide concentration). The results were used to construct a model of probe mobility and to rank the parameters in order of importance. Water content and probe size were shown to have the greatest effect. Although these assemblies are simplified templates of the plant cell walls, our strategy paves the way for proposing new approaches for optimizing biomass saccharification, such as selecting enzymes with suitable properties.

Paës G; Burr S; Saab MB; Molinari M; Aguié-Béghin V; Chabbert B

2013-07-01

333

Modeling progression of fluorescent probes in bioinspired lignocellulosic assemblies.  

Science.gov (United States)

Progression of enzymes in lignocellulosic biomass is a crucial parameter in biorefinery processes, and it appears to be one of the limiting factors in optimizing lignocellulose degradation. In order to assay the importance of the chemical and structural features of the substrate matrix on enzyme mobility, we have designed bioinspired model assemblies of secondary plant cell walls, which have been used to measure the mobility of fluorescent probes while modifying different parameters (probe size, water content, polysaccharide concentration). The results were used to construct a model of probe mobility and to rank the parameters in order of importance. Water content and probe size were shown to have the greatest effect. Although these assemblies are simplified templates of the plant cell walls, our strategy paves the way for proposing new approaches for optimizing biomass saccharification, such as selecting enzymes with suitable properties. PMID:23721261

Paës, Gabriel; Burr, Sally; Saab, Marie-Belle; Molinari, Michaël; Aguié-Béghin, Véronique; Chabbert, Brigitte

2013-06-12

334

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

335

[Progress on cellulase and enzymatic hydrolysis of lignocellulosic biomass].  

UK PubMed Central (United Kingdom)

Biofuels and bio-based chemicals from lignocellulosic biomass are sustainable, making them alternatives to petroleum-derived fuels and chemicals to address the challenges of the shortage of crude oil supply and climate change resulted from the overconsumption of petroleum-based products, particularly in China. However, high cost in liberating sugars from lignocellulosic biomass is still the bottleneck of the commercialization of biofuels and bio-based chemicals. In this article, the major components of cellulases and their synergistic role in the hydrolysis of pre-treated biomass is reviewed, followed by how to evaluate the enzymatic hydrolysis. With the elucidation of the underlying mechanism of the conformations of the enzyme molecules and their effectiveness in attacking cellulose substrate, more efficient enzymes are expected to be developed. Using the high production strain Penicillium decumbens, the on-site production of cellulases for cellulose ethanol production is discussed.

Fang X; Qin Y; Li X; Wang L; Wang T; Zhu M; Qu Y

2010-07-01

336

X-ray scattering studies of lignocellulosic biomass: a review.  

UK PubMed Central (United Kingdom)

The high processing cost of lignocellulosic ethanol is one of the most important barriers to its profitable commercialization. Pretreatments have been used to change the structure of biomass significantly and to improve sugar and ethanol yield. Great efforts have been made to understand the structural changes of biomass during these processes, including the molecular assembly of crystalline cellulose. Wide-angle and small-angle X-ray scattering are powerful techniques in studying the biomass structure at a molecular level. In this review, after we introduce the basic structure of lignocellulosic biomass, the effects of commonly used pretreatment methods on biomass structure, and the principle of X-ray scattering technique, the application of X-ray scattering, including studies of crystallinity, crystallite size, orientation distribution, and pore structure, and the related results in biomass conversion are summarized and discussed. Future study of biomass with X-ray scattering also is proposed.

Xu F; Shi YC; Wang D

2013-05-01

337

Analysis of hydroxypropyl starch hydrolysates by high performance liquid chromatography  

Energy Technology Data Exchange (ETDEWEB)

Acid hydrolysates of hydroxypropyl derivatives of wheat, maize, waxy maize and high amylose maize starches were separated using four HPLC procedures. An amine treated silica column gave best resolution of glucose and six nonglucose components. The proportions of these varied depending on the native starch and the acid used for hydrolysis. There was a linear relationship between molar substitution and ratio of nonglucose peak areas which varied between the native starches.

Wootton, M.; Kesavamoorthy, S.; Azemi, B.M.N.M.

1985-08-01

338

APPARATUS FOR REMOVING HALOGEN HYDRACIDS FROM BIOMASS HYDROLYSATES  

UK PubMed Central (United Kingdom)

An apparatus for removing hydrogen halide and water from hydrolysates that were obtained by way of halogen-acid hydrolysis from vegetable biomasses, characterized in that: - said apparatus comprises two containers, which are connected to each other by a tube, - at the inlet of the first container two flows are fed, one representing the hydrolysates and the other a heat transfer medium, which dissolves in the hydrolysate only to an economically justifiable extent (no additional process steps due to potential contamination during mixing), or enriches matter therefrom, - both flows are sprayed together in the first container, thereby producing a homogeneous mixing of the two flows, including heat transfer, which subsequently results in complete evaporation of water and the hydrogen halide dissolved in the hydrolysates, - the evaporation produces a mixture of granular solid bodies and heat transfer medium droplets, which is pulled from the first container into the second container via the connecting tube by way of a pressure gradient, - the second container is configured as a cyclone or centrifugal force precipitator, and a separation of liquid (heat transfer medium droplets) and solid constituents (granular solid bodies) from the gas flow takes place. An apparatus, characterized in that the second container (here: cyclone) on the inside wall may be lined with polyvinylchloride [PVC] (hard), PVC (chlorinated), polyethylene (PE), polypropylene (PP), polybutylene (PB), polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), ethylene-propylene-diene rubber (EPDM), ethylene-propylene copolymer, ethylene-tetrafluoroethylene (ETFE), perfluoro-ethylene-propylene plastic (FEP), fluoropolymer plastics (FPM and FKM = group designation), perfluoro trifluoroethylene (PCTFE), perfluorinated rubber (FFPM and FFKM), butyl rubber (HR), isoprene rubber (IR), chlorinated polyethylene (PE-C) and rubber (collective term for rubbers containing sulfur) and copolymers and mixtures thereof from said polymers, or comprises them.

SCHMIDT MATTHIAS; KOSE FRANK

339

Effects of selected assay parameters on measurment of lignocellulose mineralization with a radiolabeled substrate  

International Nuclear Information System (INIS)

The carbon sequestered in lignocellulose is reintroduced into the global carbon cycle primarily through microbial decomposition and mineralization. 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 affects on measured mineralization

1983-01-01

340

Effects of selected assay parameters on measurment of lignocellulose mineralization with a radiolabeled substrate  

Energy Technology Data Exchange (ETDEWEB)

The carbon sequestered in lignocellulose is reintroduced into the global carbon cycle primarily through microbial decomposition and mineralization. Varying the amount of labeled substrate or the amount of leaf material resulted in significant nonlinear changes in lignocellulose mineralization, as measured with natural (/sup 14/C)lignin-labeled lignocellulose. The use of periodic rather than continuous aeration was found not to have significant affects on measured mineralization.

Baker, K.H.

1983-03-01

 
 
 
 
341

Pelagic fish hydrolysates as peptones for bacterial culture media.  

Science.gov (United States)

For several years in the Quebec fisheries' industry, landings of pelagic fish have been calculated at over 4000 tons. These under-exploited species, rich in lipids and proteins, could be used in valuable new products. In the present study, hydrolysates of mackerel and herring were produced and utilized as sources of peptones in the formulation of new bacterial culture media. The molecular weight distribution analysis showed that molecules present in the hydrolysates were lower than 1300 Da for herring, and lower than 930 Da for mackerel. The formulated media were compared with reference media using 6 bacterial strains (3 lactic acid (LAB) and 3 non-lactic). The absorbance (OD) and carbohydrate measurements revealed that the formulated media possessed similar yields in comparison with the reference media. Finally, the inhibition of Listeria innocua by LAB bacteriocins was evaluated. Results obtained for Pediococcus acidilactici demonstrated high activities for each medium studied. Thus, the medium containing herring peptones generated the highest bacteriocin titre (32768 AU/mL), followed by both the medium containing mackerel peptones and the MRS7 medium (16384 AU/mL). Each medium containing the fish hydrolysates efficiently supported the growth of the bacterial strains. Pelagic fish peptones are promising as a novel bacterial culture media. PMID:19940932

Beaulieu, Lucie; Desbiens, Michel; Thibodeau, Jacinthe; Thibault, Sharon

2009-11-01

342

The Use of Protein Hydrolysates for Weed Control  

Science.gov (United States)

Corn gluten meal, the protein fraction of corn (Zea mays L.) grain, is commercially used as a natural weed control agent and nitrogen source in horticultural crops and in the turf and ornamental markets. Corn gluten hydrolysate, a water soluble form of gluten meal, has also been proposed for the same purpose, although it could be sprayed on the soil rather than applied in the granular form. Five depeptides, glutaminyl-glutamine (Gln-Gln), glycinyl-alanine (Gly-Ala), alanyl-­glutamine (Ala-Glu), alanyl-asparagine (Ala-Asp), and alaninyl-alanine (Ala-Ala) and a pentapeptide leucine-serine-proline-alanine-glutamine (Leu-Ser-Pro-Ala-Gln) were identified as the active components of the hydrolysate. Microscopic analysis revealed that Ala-Ala acted on some metabolic process rather than directly on the mitotic apparatus. Similar to the chloracetamides and sulfonyl-urea hebicides, Ala-Ala inhibits cell division rather than disrupting of cell division processes. Cellular ultrastructure changes caused by exposure to Ala-Ala implicate Ala-Ala as having membrane-disrupting characteristics similar to several synthetic herbicides. The potential use of the hydrolysate and the peptides as weed controls is discussed.

Christians, Nick; Liu, Dianna; Unruh, Jay Bryan

343

Rendered-protein hydrolysates for microbial synthesis of cyanophycin biopolymer.  

UK PubMed Central (United Kingdom)

Cyanophycin is a poly(arginyl-aspartate) biopolymer produced and stored intracellularly by bacteria. Cyanophycin has been proposed as a renewable replacement for petrochemical-based industrial products. An abundant source of amino acids and nitrogen such as in the form of protein hydrolysates is needed for the biosynthesis of cyanophycin. Rendered proteins are largely used as a feed supplement in animal husbandry and aquaculture. New uses would expand the market size of this class of protein coproducts. We prepared and thoroughly characterized the hydrolysates of meat and bone meal, and proceeded to demonstrate for the first time that these hydrolysates could be used in the fermentative production of cyanophycin. Using the enzyme-hydrolyzed meat and bone meal preparation, we obtained crude cyanophycin product at 33-35% level of that produced using the reference casamino acids in both shake-flask and 10-L bioreactor fermentation studies. Polyacrylamide-gel electrophoresis of the cyanophycin under denaturing conditions showed the molecular weight of the isolated polyamide at 24kDa. Our results open a new avenue for the utilization of rendered protein coproducts to produce the cyanophycin biopolymer.

Solaiman DK; Garcia RA; Ashby RD; Piazza GJ; Steinbüchel A

2011-10-01

344

Fermentation to ethanol of pentose-containing spent sulphite liquor  

Energy Technology Data Exchange (ETDEWEB)

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

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

1987-06-01

345

Study of Lignocellulose/Epoxy Composites for Carbon-neutral Insulation Materials  

Science.gov (United States)

Carbon-neutral materials, which do not affect the density of CO2 in the atmosphere even if they burn, have attracted much attention form the viewpoint of environmental friendliness. In this study, lignocellulose/epoxy composites were newly prepared as carbon-neutral insulation materials, and their properties were evaluated. Hydrothermal reaction lignocellulose, which is composed of lignin and crystalline cellulose, was prepared by a treatment of corncob under high-pressure hot water at 190°C, 1.8 MPa for 10min. The 13C-NMR spectra showed that the amounts of non-crystalline cellulose in the hydrothermal reaction lignocellulose were less than those of non-hydrothermal reaction lignocellulose. Moreover, hydrothermal reaction and oligoesterification lignocellulose was obtained by a reaction of maleic anhydride and glycidyl ether with the hydrothermal reaction lignocellulose. The epoxy resin containing the hydrothermal reaction and oligoesterification lignocellulose had lower water absorption and viscosity than those of the epoxy resin containing the non-hydrothermal reaction lignocellulose. The epoxy resin containing the hydrothermal reaction and oligoesterification lignocellulose with SiO2 fillers showed an insulation breakdown strength as same as conventional material (an epoxy resin containing SiO2 fillers). In addition, mechanical and thermal properties of the epoxy-based composite were also comparable with a conventional material. Therefore, the epoxy-based composite seems to be a candidate as practical carbon neutral insulation materials.

Komiya, Gen; Hayami, Tokusuke; Murayama, Kiyoko; Sato, Junichi; Kinoshita, Susumu; Todo, Yoko; Amano, Yoshihiko

346

Spent fuel management overview: a global perspective  

International Nuclear Information System (INIS)

The paper defines the main spent fuel management strategies and options, highlights the challenges for spent fuel storage and gives an overview of the regional balances of spent fuel storage capacity and spent fuel arising. The relevant IAEA activities in the area of spent fuel management are summarised. (author)

1999-01-01

347

Spent fuel storage  

International Nuclear Information System (INIS)

A space is formed underground by partitioning walls made of radiation shielding material, in which only a storage cell is contained. The storage cell comprises metal blocks made of a heat conductive material such as stainless steels. A great number of holes each having a predetermined diameter are vertically arranged to the metal block, and storage pits are constituted by the holes. Spent nuclear fuels are contained in a first columnar vessel and the first columnar vessel is further contained in a large second columnar vessel. Both of the first columnar vessel and the second columnar vessel are made of a durable metal material such as stainless steels. The second columnar vessel is inserted to the storage pit of the storage cell. With such a constitution, heat emitted from the second columnar vessel is transferred to the metal block by radiation and dissipated from the metal block. Accordingly, a heat dissipation efficiency can be increased. (I.N.)

1992-03-26

348

Spent fuel storage  

Energy Technology Data Exchange (ETDEWEB)

A space is formed underground by partitioning walls made of radiation shielding material, in which only a storage cell is contained. The storage cell comprises metal blocks made of a heat conductive material such as stainless steels. A great number of holes each having a predetermined diameter are vertically arranged to the metal block, and storage pits are constituted by the holes. Spent nuclear fuels are contained in a first columnar vessel and the first columnar vessel is further contained in a large second columnar vessel. Both of the first columnar vessel and the second columnar vessel are made of a durable metal material such as stainless steels. The second columnar vessel is inserted to the storage pit of the storage cell. With such a constitution, heat emitted from the second columnar vessel is transferred to the metal block by radiation and dissipated from the metal block. Accordingly, a heat dissipation efficiency can be increased. (I.N.).

Futami, Tatsuya; Sakamoto, Kazuaki.

1993-10-22

349

Spent potlining utilisation possibilities.  

UK PubMed Central (United Kingdom)

As the world's capacity for aluminium production increases, the amount of waste connected with this industry is also increasing. Spent potlining (SPL) from aluminium reduction cell cathodes presents a major environmental concern in the primary aluminium industry. It is concluded, after laboratory tests, that leachable cyanide and fluoride compounds present the major problem in SPL disposal. The behaviour of cyanide and fluoride under high temperature treatment has been investigated. On the basis of this laboratory investigation, the possibilities for SPL utilisation in red brick manufacturing, cement industry and thermal power stations were evaluated. SPL refractory material is already re-used in red brick manufacturing. In the cement industry, a pilot test on the utilisation of 25 t SPL carbon waste mixed with green petrol coke gave positive results. Additionally a fluoride emission forecast for a thermal power station utilising carbon waste SPL mixed with coal was elaborated.

Miksa D; Homsak M; Samec N

2003-10-01

350

Spent potlining utilisation possibilities.  

Science.gov (United States)

As the world's capacity for aluminium production increases, the amount of waste connected with this industry is also increasing. Spent potlining (SPL) from aluminium reduction cell cathodes presents a major environmental concern in the primary aluminium industry. It is concluded, after laboratory tests, that leachable cyanide and fluoride compounds present the major problem in SPL disposal. The behaviour of cyanide and fluoride under high temperature treatment has been investigated. On the basis of this laboratory investigation, the possibilities for SPL utilisation in red brick manufacturing, cement industry and thermal power stations were evaluated. SPL refractory material is already re-used in red brick manufacturing. In the cement industry, a pilot test on the utilisation of 25 t SPL carbon waste mixed with green petrol coke gave positive results. Additionally a fluoride emission forecast for a thermal power station utilising carbon waste SPL mixed with coal was elaborated. PMID:14661894

Miksa, Dragan; Homsak, Marko; Samec, Niko

2003-10-01

351

Spent fuel storage facility  

International Nuclear Information System (INIS)

A diffusion-preventive device for the radioactivity of pool water is disposed in a pool chamber for accommodating a spent fuel storage chamber. The diffusion-preventive device comprises an air washer and a recycling blower which discharges air in the air washer to the pool chamber. In this air washer, not-activated pure water, etc. are supplied. The recycling blower is driven to introduce the air in the pool chamber to the air washer, and water is sprayed from a nozzle to moisten the air. In this way, the vapor pressure in the pool chamber can be increased and the amount of vapor generated from the pool can be decreased. The amount of radioactivity transferring from the poor water to the air can thereby be decreased and the amount of radioactivity released to the atmospheric air by means of ventilation air conditioning device can be decreased. (I.N.).

1988-06-16

352

FISH PROTEIN HYDROLYSATE HAVING A SATIETOGENIC ACTIVITY, NUTRACEUTICAL AND PHARMACOLOGICAL COMPOSITIONS COMPRISING SUCH A HYDROLYSATE AND METHOD FOR OBTAINING SAME,  

UK PubMed Central (United Kingdom)

The present invention relates to a fish protein hydrolysate containing molecules capable of exerting a satietogenic activity and of regulating food intake in humans or animals. More specifically, the protein hydrolysate according to the invention enables stimulation of the secretion of endogenous cholescystokinins (CCKs) and of endogenous glucagon-like peptide 1 (GLP1) molecules by intestinal cells and the supply of exogenous CCKs. The fish protein hydrolysate according to the invention is obtained by enzymatic hydrolysis of at least one protein source selected from the group composed of the pelagic fish species Micromesistius poutassou, Clupea harengus, Scomber scombrus, Sardina pilchardus, Trisopterus esmarki and Trachurus spp., the demersal fish species Gadus morhua, Pollachius virens, Melanogrammus aeglefinus and Coryphaenoides rupestris, and the species of fish belonging to the order Siluriformes, said enzymatic hydrolysis being carried out by means of a mixture of enzymes comprising endopeptidases derived from Bacillus amyloliquefaciens and from Bacillus licheniformis, or derived from Bacillus amyloliquefaciens, from Bacillus licheniformis and from Aspergillus oryzae.

DRIEU LA ROCHELLE HUBERT; COUROIS ELISA; CUDENNEC BENOIT; FOUCHEREAU-PERON MARTINE; RAVALLEC-PLE ROZENN

353

FISH PROTEIN HYDROLYSATE HAVING A SATIETOGENIC ACTIVITY, NUTRACEUTICAL AND PHARMACOLOGICAL COMPOSITIONS COMPRISING SUCH A HYDROLYSATE AND METHOD FOR OBTAINING SAME  

UK PubMed Central (United Kingdom)

The present invention relates to a fish protein hydrolysate containing molecules capable of exerting a satietogenic activity and of regulating food intake in humans or animals. More specifically, the protein hydrolysate according to the invention enables stimulation of the secretion of endogenous cholescystokinins (CCKs) and of endogenous glucagon-like peptide 1 (GLP1) molecules by intestinal cells and the supply of exogenous CCKs.; The fish protein hydrolysate according to the invention is obtained by enzymatic hydrolysis of at least one protein source selected from the group composed of the pelagic fish species Micromesistius poutassou, Clupea harengus, Scomber scombrus, Sardina pilchardus, Trisopterus esmarki and Trachurus spp., the demersal fish species Gadus morhua, Pollachius virens, Melanogrammus aeglefinus and Coryphaenoides rupestris, and the species of fish belonging to the order Siluriformes, said enzymatic hydrolysis being carried out by means of a mixture of enzymes comprising endopeptidases derived from Bacillus amyloliquefaciens and from Bacillus licheniformis,or derived from Bacillus amyloliquefaciens, from Bacillus licheniformis and from Aspergillus oryzae.

DRIEU LA ROCHELLE HUBERT; COUROIS ELISA; CUDENNEC BENOIT; FOUCHEREAU-PERON MARTINE; RAVALLEC-PLE ROZENN

354

Protein Hydrolysates from Agricultural Crops—Bioactivity and Potential for Functional Food Development  

Directory of Open Access Journals (Sweden)

Full Text Available There has been an unprecedented demand for inexpensive plant-derived protein hydrolysates in recent years, owing to their potential nutritional applications. This review examines existing evidence regarding protein hydrolysates from agricultural crops such as wheat, soy, rapeseed, sunflower and barley. The bioactivity of these protein hydrolysates, including antioxidant and anti-inflammatory capabilities are discussed. In addition to evidence regarding their potential to enhance human nutrition, the effect of the hydrolysates on the techno-functional properties of foods will be reviewed.

Aoife L. McCarthy; Yvonne C. O'Callaghan; Nora M. O'Brien

2013-01-01

355

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

356

Results of transporting spent fuel  

Energy Technology Data Exchange (ETDEWEB)

Spent fuel increases year after year as full-scale nuclear power generation has been carried out, and in Japan, all spent fuel is to be reprocessed in view of the effective use of resources and the adequate disposal of radioactive wastes. In 1983, the spent fuel transported to the reprocessing plants in Japan and foreign countries reached about 380 t uranium. The transport of spent fuel in Japan began with that from a research reactor in the Japan Atomic Energy Research Institute to USA in August, 1966. Thereafter, the spent fuel from nuclear power stations has been transported to the reprocessing plants in Great Britain and France. In September, 1977, the Tokai reprocessing plant started the trial operation, and in January, 1978, spent fuel was first transported to the plant. The plant was shut down in February, 1983, due to the failure of a uranium dissolving tank. The plate fuel for research reactors cannot be reprocessed in Japan, accordingly, it is to be transported to foreign plants hereafter. 1600 t each of the spent fuel from nuclear power stations will be reprocessed in Great Britain and France, and four ships of PNTL carry out the transport. In the transport for reprocessing in Japan, HZ-75T transport containers are used, and the special freighter ''Hinoura-maru'' is used.

Sawayama, Ken-ichi (Ministry of Transportation, Tokyo (Japan))

1984-10-01

357

Assessment of spent fuel cooling  

Energy Technology Data Exchange (ETDEWEB)

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

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

1997-02-01

358

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

359

Efficacy of cellulase and mannanase hydrolysates of konjac glucomannan to promote the growth of lactic acid bacteria  

UK PubMed Central (United Kingdom)

BACKGROUND: Glucomannan polysaccharides may be hydrolysed to lower molecular weight molecules using acids or enzymes, specifically mannanases or cellulases. Mannanases (??mannanases) hydrolyse ??(1–4)?linked mannose residues randomly in mannans whilst cellulases (??glucanase) hydrolyse ??(1–4)?linked glucose residues. The molecular weight of the hydrolysate is clearly dependent on the amount of hydrolysis. One use of such hydrolysates has been towards their capacity to function as prebiotics. The relative efficacy of cellulase and/or mannanase hydrolysates of konjac glucomannan to promote the growth of lactic acid bacteria (LAB) has been evaluated. RESULTS: The LAB growth profiles (expressed in colony forming units, as a function of time) in UHT milk containing konjac glucomannan hydrolysed with cellulase were significantly greater than those containing glucose (control) or konjac glucomannan mannanase hydrolysates. An equivalent mixture (1:1) of cellulase–mannanase hydrolysates added to the UHT milk also showed significant improvement on the LAB growth profiles (compared to the glucose or mannanase alone hydrolysates). Different LAB strains showed some variation in growth profiles on the hydrolysates although this was not significant as a function of carbon source. CONCLUSIONS: Glucomannan hydrolysates produced with either mannanase or cellulase enzymes were effective growth promoters (carbon sources) of LAB. However, cellulase hydrolysates were most effective.

Al?Ghazzewi FH; Tester RF

2012-08-01

360

Efficacy of cellulase and mannanase hydrolysates of konjac glucomannan to promote the growth of lactic acid bacteria.  

UK PubMed Central (United Kingdom)

BACKGROUND: Glucomannan polysaccharides may be hydrolysed to lower molecular weight molecules using acids or enzymes, specifically mannanases or cellulases. Mannanases (?-mannanases) hydrolyse ?-(1-4)-linked mannose residues randomly in mannans whilst cellulases (?-glucanase) hydrolyse ?-(1-4)-linked glucose residues. The molecular weight of the hydrolysate is clearly dependent on the amount of hydrolysis. One use of such hydrolysates has been towards their capacity to function as prebiotics. The relative efficacy of cellulase and/or mannanase hydrolysates of konjac glucomannan to promote the growth of lactic acid bacteria (LAB) has been evaluated. RESULTS: The LAB growth profiles (expressed in colony forming units, as a function of time) in UHT milk containing konjac glucomannan hydrolysed with cellulase were significantly greater than those containing glucose (control) or konjac glucomannan mannanase hydrolysates. An equivalent mixture (1:1) of cellulase-mannanase hydrolysates added to the UHT milk also showed significant improvement on the LAB growth profiles (compared to the glucose or mannanase alone hydrolysates). Different LAB strains showed some variation in growth profiles on the hydrolysates although this was not significant as a function of carbon source. CONCLUSIONS: Glucomannan hydrolysates produced with either mannanase or cellulase enzymes were effective growth promoters (carbon sources) of LAB. However, cellulase hydrolysates were most effective.

Al-Ghazzewi FH; Tester RF

2012-08-01

 
 
 
 
361

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

UK PubMed Central (United Kingdom)

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

Sharma RK; Arora DS

2013-07-01

362

Detailed kinetic and heat transport model for the hydrolysis of lignocellulose by anhydrous hydrogen fluoride vapor  

Energy Technology Data Exchange (ETDEWEB)

Anhydrous Hydrogen Fluoride (HF) vapor at ambient conditions efficiently and rapidly hydrolyzed lignocellulose to glucose and lignin. The unsteady-state reaction of HF vapor with a single lignocellulose chip was mathematically modeled under conditions where external and internal mass-transfer resistances were minimized. The model incorporated physical adsorption of HF vapor onto the lignocellulosic matrix and solvolysis of cellulose to glucosyl fluoride by adsorbed HF into the differential material and energy balance expressions. Model predictions for the temperature distribution and global glucose yield in the HF-reacting lignocellulose chip as a function of reaction time and HF vapor stream temperature agreed reasonably with the complimentary experimental data. The model correctly predicted that even when mass-transfer resistances for the reaction of HF vapor with a single lignocellulose chip are minimized, external and internal heat-transfer resistances are still significant.

Rorrer, G.L.; Mohring, W.R.; Lamport, D.T.A.; Hawley, M.C.

1988-01-01

363

Comparative environmental performance of lignocellulosic ethanol from different feedstocks  

International Nuclear Information System (INIS)

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

2010-01-01

364

Hydrolysis of polysaccharides of corncob lignocellulose by concentrated sulfuric acid  

Energy Technology Data Exchange (ETDEWEB)

The hydrolysis of polysaccharides of corncob lignocellulose in the presence of concentrated H/sub 2/SO/sub 4/ at 130 degrees, and methods for decreasing H/sub 2/SO/sub 4/ consumption, are discussed. The polysaccharides undergo homogeneous hydrolysis only at H/sub 2/SO/sub 4/ concentration greater than or equal to 57.9%. Lignin is completely deactivated during hydrolysis of hemicellulose and does not form a molecular complex with H/sub 2/SO/sub 4/. This deactivation lowers the liquor (80% H/sub 2/SO/sub 4/) ratio to 1.28.

Yablochkina, S.P.; Kozlova, L.V.; Chalov, N.V.

1982-01-01

365

Removal of inhibitors from lignocellulosic hydrolyzates by vacuum membrane distillation.  

Science.gov (United States)

In this study, vacuum membrane distillation (VMD) was used to remove two prototypical fermentation inhibitors (acetic acid and furfural) from lignocellulose hydrolyzates. The effect of operating parameters, such as feed temperature and feed velocity, on the removal efficiencies of inhibitors was investigated. Under optimal conditions, more than 98% of furfural could be removed by VMD. However, the removal efficiency of acetic acid was considerably lower. After furfural and acetic acid were selectively removed from hydrolyzates by VMD, ethanol production efficiency increased by 17.8% compared to original hydrolyzates. PMID:23907067

Chen, Jingwen; Zhang, Yaqin; Wang, Yafei; Ji, Xiaosheng; Zhang, Lin; Mi, Xigeng; Huang, He

2013-07-11

366

Recent developments in fast pyrolysis of ligno-cellulosic materials.  

UK PubMed Central (United Kingdom)

Pyrolysis is a thermochemical process to convert ligno-cellulosic materials into bio-char and pyrolysis oil. This oil can be further upgraded or refined for electricity, transportation fuels and chemicals production. At the time of writing, several demonstration factories are considered worldwide aiming at maturing the technology. Research is focusing on understanding the underlying processes at all relevant scales, ranging from the chemistry of cell wall deconstruction to optimization of pyrolysis factories, in order to produce better quality oils for targeted uses. Among the several bio-oil applications that are currently investigated the production and fermentation of pyrolytic sugars explores the promising interface between thermochemistry and biotechnology.

Kersten S; Garcia-Perez M

2013-06-01

367

PRODUCTION OF BIODIESEL BY YEAST FROM LIGNOCELLULOSE AND GLYCEROL  

UK PubMed Central (United Kingdom)

The invention is directed to a genetically modified microorganism for the extracellular production of free fatty acids and esters thereof, wherein said microorganism is characterised by a modified lipid biosynthesis metabolic pathway: for example reduced fatty acyl-coA synthetase activity that enables the microorganism to overproduce and secrete of esters of fatty acids (Biodiesel) into the surrounding medium, using one or more of: glucose, starch, lignocellulose and a glycerol-based substrate, as a carbon source. The invention further provides a method for the extracellular production of free fatty acids and esters thereof, comprising the use of said genetically modified organism, and a growth medium adapted for said method.

PHADNAVIS AMBAREESH GOVIND

368

Cellulosic ethanol: progress towards a simulation model of lignocellulosic biomass  

Science.gov (United States)

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.

Petridis, L.; Smith, J. C.

2008-07-01

369

Cellulosic ethanol: progress towards a simulation model of lignocellulosic biomass  

International Nuclear Information System (INIS)

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

2008-01-01

370

Removal of inhibitors from lignocellulosic hydrolyzates by vacuum membrane distillation.  

UK PubMed Central (United Kingdom)

In this study, vacuum membrane distillation (VMD) was used to remove two prototypical fermentation inhibitors (acetic acid and furfural) from lignocellulose hydrolyzates. The effect of operating parameters, such as feed temperature and feed velocity, on the removal efficiencies of inhibitors was investigated. Under optimal conditions, more than 98% of furfural could be removed by VMD. However, the removal efficiency of acetic acid was considerably lower. After furfural and acetic acid were selectively removed from hydrolyzates by VMD, ethanol production efficiency increased by 17.8% compared to original hydrolyzates.

Chen J; Zhang Y; Wang Y; Ji X; Zhang L; Mi X; Huang H

2013-09-01

371

Biotransformation of lignocellulose to fertilizers enriched with humic acids  

Energy Technology Data Exchange (ETDEWEB)

This work is directed to the investigation of possibility of ultrasound treatment for the destruction of lignocellulose during humification of vegetable raw-material. Microorganisms of strain Bacillus subtilis PrEA were used for biodestruction. Destruction of cellulose at optimal biodestruction parameters was reach up to 26% (bonedry), and lignin - of 11%. During the cultivation of microorganism of Bacillus genus on ultrasound pretreated sunflower husks the yield of humic acids increased from 0.6 up to 1.3 g/l, the time of fermentation decreased from 30 up to 18 days depending on the physiological state of microorganisms. (orig.)

Sulman, Esfir; Prutenskaya, E.; Molchanov, V.; Sulman, M. [Tver Technical Univ. (Russian Federation)

2010-07-01

372

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

373

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

374

Fast reactor spent fuel processing  

International Nuclear Information System (INIS)

[en] 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

375

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; Afshin Ebrahimpour; Azizah Abdul-Hamid; Farooq Anwar; Nazamid Saari

2012-01-01

376

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

377

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

UK PubMed Central (United Kingdom)

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.

Choi YJ; Hur S; Choi BD; Konno K; Park JW

2009-01-01

378

Thermal stability of yeast hydrolysate as a novel anti-obesity material.  

UK PubMed Central (United Kingdom)

We examined the thermal stability of yeast hydrolysates before and after ultrafiltration (UF) in vitro, and the anti-obesity activity of yeast hydrolysates before and after heat treatment in vivo. Yeast hydrolysate after UF showed significantly higher thermal stability than before UF. Yeast hydrolysates before and after UF showed 3 and 4 thermal transition peaks in their thermograms, respectively, and the total thermal denaturation enthalpies of yeast hydrolysates before and after UF were 69.5 and 36.5 J/g, respectively. For the anti-obesity activity study, yeast hydrolysates before and after heating were administered ad libitum with water to 7-week-old male SD rats. The administration of yeast hydrolysate (YH-control; no heat treatment, YH-1; heat treatment at 140°C, and YH-2; heat treatment at 160°C) significantly increased mRNA expression of cocaine- and amphetamine-regulated transcript (CART) compared with control rats (saline administration). However, there was no significant difference between the heat-treated groups and YH-control and there was no significant difference in neuropeptide Y expression between the heat-treated groups and YH-control. These results suggest that yeast hydrolysate can be use an anti-obesity material after heat treatment.

Park Y; Kim JH; Lee HS; Jung EY; Lee H; Noh DO; Suh HJ

2013-01-01

379

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

Science.gov (United States)

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

Nongonierma, Alice B; FitzGerald, Richard J

2012-12-03

380

Optimization of Novel Extracellular Polysaccharide Production by an Enterobacter sp, on Wood Hydrolysates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An environmental isolate identified as Enterobacter cloacae has been found to produce a highly viscous, anionic extracellular polysaccharide (EPS) from a weak mineral acid hydrolysate of hardwood. Production of this EPS has been optimized on the hydrolysate (initial pH, 6.3; NH4Cl amendment, 0.1%) s...

Meade, Maura J.; Tanenbaum, S. W.; Nakas, J. P.

 
 
 
 
381

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

UK PubMed Central (United Kingdom)

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

Nongonierma AB; FitzGerald RJ

2013-01-01

382

Rapid Differentiation Between Nocardia and Streptomyces by Paper Chromatography of Whole-Cell Hydrolysates  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Whole-cell hydrolysates were prepared from 58 strains of nocardiae and streptomycetes. Strains morphologically intermediate between the two genera and morphological variants of the same strains were included. Paper chromatograms made from the whole-cell hydrolysates clearly demonstrated meso-diamino...

Becker, B.; Lechevalier, Mary P.; Gordon, Ruth E.; Lechevalier, H. A.

383

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

UK PubMed Central (United Kingdom)

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.

Zarei M; Ebrahimpour A; Abdul-Hamid A; Anwar F; Saari N

2012-01-01

384

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

Science.gov (United States)

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