Sample records for autohydrolysis

  1. Autohydrolysis Pretreatment of Lignocellulosic Biomass for Bioethanol Production (United States)

    Han, Qiang

    Autohydrolysis, a simple and environmental friendly process, has long been studied but often abandoned as a financially viable pretreatment for bioethanol production due to the low yields of fermentable sugars at economic enzyme dosages. The introduction of mechanical refining can generate substantial improvements for autohydrolysis process, making it an attractive pretreatment technology for bioethanol commercialization. In this study, several lignocellulosic biomass including wheat straw, switchgrass, corn stover, waste wheat straw have been subjected to autohydrolysis pretreatment followed by mechanical refining to evaluate the total sugar recovery at affordable enzyme dosages. Encouraging results have been found that using autohydrolysis plus refining strategy, the total sugar recovery of most feedstock can be as high as 76% at 4 FPU/g enzymes dosages. The mechanical refining contributed to the improvement of enzymatic sugar yield by as much as 30%. Three non-woody biomass (sugarcane bagasse, wheat straw, and switchgrass) and three woody biomass (maple, sweet gum, and nitens) have been subjected to autohydrolysis pretreatment to acquire a fundamental understanding of biomass characteristics that affect the autohydrolysis and the following enzymatic hydrolysis. It is of interest to note that the nonwoody biomass went through substantial delignification during autohydrolysis compared to woody biomass due to a significant amount of p-coumaric acid and ferulic acid. It has been found that hardwood which has a higher S/V ratio in the lignin structure tends to have a higher total sugar recovery from autohydrolysis pretreatment. The economics of bioethanol production from autohydrolysis of different feedstocks have been investigated. Regardless of different feedstocks, in the conventional design, producing bioethanol and co-producing steam and power, the minimum ethanol revenues (MER) required to generate a 12% internal rate of return (IRR) are high enough to


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    Full Text Available The aim of the work was investigation of the effect of the explosive autohydrolysis on lignocellulosic biomass (saving, switchgrass biomass for consequent use as a substrate to produce biofuels such as butanol. Butanol-producing strains, switchgrass Panicum virgatum L. biomass and its components after autohydrolysis were used in study. The thermobaric pressure pretreatment of lignocellulosic biomass was carried out using specially designed equipment. The effect of explosive autohydrolysis on lignocellulosic biomass for further use in producing biofuels using microbial conversion was studied. Components of lignocellulosic biomass were fractionated after undergoing thermobaric treatment. The possibility of using different raw material components after using explosive autohydrolysis processing to produce biobutanol was found. Products of switchgrass biomass autohydrolysis were shown to need further purification before fermentation from furfural formed by thermobaric pretreatment and inhibiting the growth of microorganisms. The ability of strains of the genus Clostridium to use cellulose as a substrate for fermentation was proved. It was found that using explosive autohydrolysis pretreatment to savings allowed boosting the butanol accumulation by 2 times.

  3. Autohydrolysis pretreatment assessment in ethanol production from agave bagasse. (United States)

    Rios-González, Leopoldo J; Morales-Martínez, Thelma K; Rodríguez-Flores, María F; Rodríguez-De la Garza, José A; Castillo-Quiroz, David; Castro-Montoya, Agustín J; Martinez, Alfredo


    The aim of the present work was to assess the autohydrolysis pretreatment of Agave tequilana bagasse for ethanol production. The pretreatment was conducted using a one-liter high pressure Parr reactor under different severity factors (SF) at a 1:6w/v ratio (solid:liquid) and 200rpm. The solids obtained under the selected autohydrolysis conditions were subjected to enzymatic hydrolysis with a commercial cellulase cocktail, and the enzymatic hydrolysate was fermented using Saccharomyces cerevisiae. The results obtained from the pretreatment process showed that the glucan content in the pretreated solid was mostly preserved, and an increase in the digestibility was observed for the case with a SF of 4.13 (190°C, 30min). Enzymatic hydrolysis of the pretreated solids showed a yield of 74.3%, with a glucose concentration of 126g/L, resulting in 65.26g/L of ethanol after 10h of fermentation, which represent a 98.4% conversion according to the theoretical ethanol yield value. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Optimization of autohydrolysis conditions to extract antioxidant phenolic compounds from spent coffee grounds

    DEFF Research Database (Denmark)

    Ballesteros, Lina F.; Ramirez, Monica J.; Orrego, Carlos E.


    Autohydrolysis, which is an eco-friendly technology that employs only water as extraction solvent, was used to extract antioxidant phenolic compounds from spent coffee grounds (SCG). Experimental assays were carried out using different temperatures (160–200 °C), liquid/solid ratios (5–15 ml/g SCG.......46 mg TE/g SCG, and TAA = 66.21 mg α-TOC/g SCG) consisted in using 15 ml water/g SCG, at 200 °C during 50 min. Apart from being a green technology, autohydrolysis under optimized conditions was demonstrated to be an efficient method to extract antioxidant phenolic compounds from SCG....

  5. Fractionation of hemicelluloses and lignin from rice straw by combining autohydrolysis and optimised mild organosolv delignification

    NARCIS (Netherlands)

    Moniz, Patrícia; Lino, João; Duarte, Luís C.; Roseiro, Luísa B.; Boeriu, Carmen G.; Pereira, Helena; Carvalheiro, Florbela


    An integrated strategy was followed to valorise rice straw, one of the most relevant biomass feedstocks available worldwide, to selectively recover solubilised hemicelluloses and lignin. The pathway encompassed the use of autohydrolysis to hydrolyse the hemicelluloses and an ethanol-based

  6. Combining autohydrolysis and ionic liquid microwave treatment to enhance enzymatic hydrolysis of Eucalyptus globulus wood. (United States)

    Rigual, Victoria; Santos, Tamara M; Domínguez, Juan Carlos; Alonso, M Virginia; Oliet, Mercedes; Rodriguez, Francisco


    The combination of autohydrolysis and ionic liquid microwave treatments of eucalyptus wood have been studied to facilitate sugar production in a subsequent enzymatic hydrolysis step. Three autohydrolysis conditions (150 °C, 175 °C and 200 °C) in combination with two ionic liquid temperatures (80 °C and 120 °C) were compared in terms of chemical composition, enzymatic digestibility and sugar production. Morphology was measured (using SEM) and the biomass surface was visualized with confocal fluorescence microscopy. The synergistic cooperation of both treatments was demonstrated, enhancing cellulose accessibility. At intermediate autohydrolysis conditions (175 °C) and low ionic liquid temperature (80 °C), a glucan digestibility of 84.4% was obtained. Using SEM micrographs, fractal dimension (as a measure of biomass complexity) and lacunarity (as a measure of homogeneity) were calculated before and after pretreatment. High fractals dimensions and low lacunarities correspond to morphologically complex and homogeneous samples, that are better digested by enzyme cocktails. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Autohydrolysis processing as an alternative to enhance cellulose solubility and preparation of its regenerated bio-based materials

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    Gan, Sinyee, E-mail:; Zakaria, Sarani, E-mail:; Chen, Ruey Shan; Chia, Chin Hua; Padzil, Farah Nadia Mohammad; Moosavi, Seyedehmaryam


    Kenaf core pulp has been successfully autohydrolysed using an autoclave heated in oil bath at various reaction temperature at 100, 120 and 140 °C. Membranes, hydrogels and aerogels were then prepared from autohydrolysed kenaf in urea/alkaline medium by casting on the glass plate, by using epichlorohydrin (ECH) as cross-linker via stirring and freeze-drying method, respectively. The autohydrolysis process reduced the molecular weight of cellulose and enhanced cellulose solubility and viscosity. Structure and properties of the regenerated products were measured with Field emission scanning electron microscope (FESEM), X-ray diffraction (XRD), Ultraviolet–visible (UV–Vis) spectrophotometer and swelling testing. As the autohydrolysis temperature increased, the porosity of cellulose membranes (as seen from the morphology) increased. The autohydrolysis process improved the swelling porperties and transparency of regenerated cellulose hydrogels. This finding is expected to be useful in reducing molecular weight of cellulose in order to produce regenerated bio-based cellulose materials. - Highlights: • Autohydrolysis temperature is negatively correlated to cellulose molecular weight. • Cellulose solubility and viscosity are improved after cellulose pretreatment. • Autohydrolysis improved the properties of regenerated cellulose materials.

  8. Effects of autohydrolysis of Eucalyptus urograndis and Eucalyptus grandis on influence of chemical components and crystallinity index. (United States)

    da Silva Morais, Alaine Patrícia; Sansígolo, Cláudio Angeli; de Oliveira Neto, Mario


    Samples of Eucalyptus urograndis and Eucalyptus grandis sawdust were autohydrolyzed in aqueous conditions to reach temperatures in the range 110-190°C and reaction times of 0-150min in a minireactor. In each minireactor were used a liquor:wood ratio (10:1 L:kg dry wood), in order to assess the effects of the autohydrolysis severity and the crystalline properties of cellulose. The content of extractives, lignin, holocellulose, cellulose, hemicelluloses and crystallinity index obtained from the solid fraction after autohydrolysis of sawdust were determined. This study demonstrated that the hemicelluloses were extensively removed at 170 and 190°C, whereas cellulose was partly degraded to Eucalyptus urograndis and Eucalyptus grandis sawdust. The lignin content decreased, while the extractives content increased. It was defined that during autohydrolysis, had a slight decreased on crystalline structure of cellulose of Eucalyptus urogandis and Eucalyptus grandis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Multivariate Correlation between Analysis Data on Dissolved Organic Material from Scots Pine (Pinus sylvestris Chips and their Autohydrolysis Pre-Treatment Conditions

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    Joni Lehto


    Full Text Available Various chemometric techniques were used to establish the relationship between the autohydrolysis conditions prior to pulping and the chemical compositions of the soluble organic materials removed from Scots pine (Pinus sylvestris wood chips. The aqueous chip pre-treatments (autohydrolysis were administered at 130 °C and 150 °C for 30, 60, 90, and 120 min, and the hydrolysates obtained were characterized in terms of total carbohydrates (various mono-, oligo-, and polysaccharides together with uronic acid side groups, volatile acids (acetic and formic acids, lignin, and furans (furfural and 5-(hydroxymethylfurfural. Based on the analytical data gathered, a relatively accurate model for pine chip autohydrolysis was developed.

  10. Comparison of microwave and conduction-convection heating autohydrolysis pretreatment for bioethanol production. (United States)

    Aguilar-Reynosa, Alejandra; Romaní, Aloia; Rodríguez-Jasso, Rosa M; Aguilar, Cristóbal N; Garrote, Gil; Ruiz, Héctor A


    This work describes the application of two forms of heating for autohydrolysis pretreatment on isothermal regimen: conduction-convection heating and microwave heating processing using corn stover as raw material for bioethanol production. Pretreatments were performed using different operational conditions: residence time (10-50 min) and temperature (160-200°C) for both pretreatments. Subsequently, the susceptibility of pretreated solids was studied using low enzyme loads, and high substrate loads. The highest conversion was 95.1% for microwave pretreated solids. Also solids pretreated by microwave heating processing showed better ethanol conversion in simultaneous saccharification and fermentation process (92% corresponding to 33.8g/L). Therefore, microwave heating processing is a promising technology in the pretreatment of lignocellulosic materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Ethanol production from olive prunings by autohydrolysis and fermentation with Candida tropicalis

    Energy Technology Data Exchange (ETDEWEB)

    Garcia Martin, Juan Francisco; Bravo, Vicente [Department of Chemical Engineering, University of Granada, Campus Universitario de Fuentenueva, 18071 Granada (Spain); Cuevas, Manuel; Sanchez, Sebastian [Department of Chemical, Environmental and Materials Engineering, University of Jaen, Campus Las Lagunillas, 23071 Jaen (Spain)


    Hydrolysates from olive prunings (a renewable, low-cost, easily available, agricultural residue) were fermented with the unconventional yeast Candida tropicalis NBRC 0618 to produce not only ethanol fuel but also xylitol as a by-product, which adds value to the economic viability of the bioprocess. Autohydrolysis took place at 200 C in a stirred stainless-steel tank reactor. The influence of the solid/liquid ratio in the reactor was studied. Fermentation experiments were conducted in a batch-culture reactor at a temperature of 30 C, a stirring rate of 500 rpm and pH values of between 5.0 and 6.5. Under the operating conditions tested the highest yields of ethanol and xylitol were obtained with the hydrolysate fermented at pH 5.0 and solely the airflow that entered via the stirring vortex. Under these conditions, the instantaneous ethanol yield was 0.44 g g{sup -1} and the overall xylitol yield 0.13 g g{sup -1}. (author)

  12. Evaluation of jumbo squid (Dosidicus gigas byproduct hydrolysates obtained by acid-enzymatic hydrolysis and by autohydrolysis in practical diets for Pacific white shrimp (Litopenaeus vannamei

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    Mayra Lizett González-Félix


    Full Text Available The marine bioprocessing industry offers great potential to utilize byproducts for fish meal replacement in aquafeeds. Jumbo squid is an important fishery commodity in Mexico, but only the mantle is marketed. Head, fins, guts and tentacles are discarded in spite of being protein-rich byproducts. This study evaluated the use of two jumbo squid byproduct hydrolysates obtained by acid-enzymatic hydrolysis (AEH and by autohydrolysis (AH as ingredients in practical diets for shrimp. The hydrolysates were included at levels of 2.5 and 5.0% of the diet dry weight in four practical diets, including a control diet without hydrolysate. Shrimp growth and survival were not significantly affected by the dietary treatments. Postharvest quality of abdominal muscle was evaluated in terms of proximate composition and sensory evaluation. Significantly higher crude protein was observed in the muscle of shrimp fed the highest hydrolysate levels, AH 5% (204.8 g kg- 1 or AEH 5% (201.3 g kg- 1. Sensory analysis of cooked muscle showed significant differences for all variables evaluated: color, odor, flavor, and firmness. It was concluded that Jumbo squid byproducts can be successfully processed by autohydrolysis or acid-enzymatic hydrolysis, and that up to 5.0% of the hydrolysates can be incorporated into shrimp diets without affecting growth or survival.

  13. Fractionation of bamboo culms by autohydrolysis, organosolv delignification and extended delignification: understanding the fundamental chemistry of the lignin during the integrated process. (United States)

    Wen, Jia-Long; Sun, Shao-Ni; Yuan, Tong-Qi; Xu, Feng; Sun, Run-Cang


    Bamboo (Phyllostachys pubescens) was successfully fractionated using a three-step integrated process: (1) autohydrolysis pretreatment facilitating xylooligosaccharide (XOS) production (2) organosolv delignification with organic acids to obtain high-purity lignin, and (3) extended delignification with alkaline hydrogen peroxide (AHP) to produce purified pulp. The integrated process was comprehensively evaluated by component analysis, SEM, XRD, and CP-MAS NMR techniques. Emphatically, the fundamental chemistry of the lignin fragments obtained from the integrated process was thoroughly investigated by gel permeation chromatography and solution-state NMR techniques (quantitative (13)C, 2D-HSQC, and (31)P-NMR spectroscopies). It is believed that the integrated process facilitate the production of XOS, high-purity lignin, and purified pulp. Moreover, the enhanced understanding of structural features and chemical reactivity of lignin polymers will maximize their utilizations in a future biorefinery industry. Copyright © 2013 Elsevier Ltd. All rights reserved.

  14. Interactions between Cellulolytic Enzymes with Native, Autohydrolysis, and Technical Lignins and the Effect of a Polysorbate Amphiphile in Reducing Nonproductive Binding. (United States)

    Fritz, Consuelo; Ferrer, Ana; Salas, Carlos; Jameel, Hasan; Rojas, Orlando J


    Understanding enzyme-substrate interactions is critical in designing strategies for bioconversion of lignocellulosic biomass. In this study we monitored molecular events, in situ and in real time, including the adsorption and desorption of cellulolytic enzymes on lignins and cellulose, by using quartz crystal microgravimetry and surface plasmon resonance. The effect of a nonionic surface active molecule was also elucidated. Three lignin substrates relevant to the sugar platform in biorefinery efforts were considered, namely, hardwood autohydrolysis cellulolytic (HWAH), hardwood native cellulolytic (MPCEL), and nonwood native cellulolytic (WSCEL) lignin. In addition, Kraft lignins derived from softwoods (SWK) and hardwoods (HWK) were used as references. The results indicated a high affinity between the lignins with both, monocomponent and multicomponent enzymes. More importantly, the addition of nonionic surfactants at concentrations above their critical micelle concentration reduced remarkably (by over 90%) the nonproductive interactions between the cellulolytic enzymes and the lignins. This effect was hypothesized to be a consequence of the balance of hydrophobic and hydrogen bonding interactions. Moreover, the reduction of surface roughness and increased wettability of lignin surfaces upon surfactant treatment contributed to a lower affinity with the enzymes. Conformational changes of cellulases were observed upon their adsorption on lignin carrying preadsorbed surfactant. Weak electrostatic interactions were determined in aqueous media at pH between 4.8 and 5.5 for the native cellulolytic lignins (MPCEL and WSCEL), whereby a ∼20% reduction in the enzyme affinity was observed. This was mainly explained by electrostatic interactions (osmotic pressure effects) between charged lignins and cellulases. Noteworthy, adsorption of nonionic surfactants onto cellulose, in the form cellulose nanofibrils, did not affect its hydrolytic conversion. Overall, our results

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

    DEFF Research Database (Denmark)

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


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

  16. Membrane separation and characterisation of lignin and its derived products obtained by a mild ethanol organosolv treatment of rice straw

    NARCIS (Netherlands)

    Moniz, Patrícia; Serralheiro, Cláudia; Matos, Cristina T.; Boeriu, Carmen G.; Frissen, Augustinus E.; Duarte, Luís C.; Roseiro, Luísa B.; Pereira, Helena; Carvalheiro, Florbela


    An organosolv process using ethanol-water was optimized in order to recover high quality lignin from rice-straw previously pre-treated by autohydrolysis at 210 °C. The results showed a selective and appreciable removal of lignin under very mild conditions and the highest delignification yield

  17. Production and physicochemical properties of carboxymethyl cellulose films enriched with spent coffee grounds polysaccharides

    DEFF Research Database (Denmark)

    Ballesteros, Lina F.; Cerqueira, Miguel A.; Teixeira, Jose A.


    Extracts rich in polysaccharides were obtained by alkali pretreatment (PA) or autohydrolysis (PB) of spent coffee grounds, and incorporated into a carboxymethyl cellulose (CMC)-based film aiming at the development of bio-based films with new functionalities. Different concentrations of PA or PB (up...

  18. Extraction of hemicelluloses from wood in a pulp biorefinery, and subsequent fermentation into ethanol

    International Nuclear Information System (INIS)

    Boucher, Jérémy; Chirat, Christine; Lachenal, Dominique


    Highlights: • Hemicellulosic ethanol from softwood hemicelluloses in a pulp mill. • Comparison of acid hydrolysis and autohydrolysis to extract hemicelluloses. • Effects of the extraction process conditions on inhibitors concentrations. • Effects of inhibitors on fermentation. - Abstract: This study deals with the production of ethanol and paper pulp in a kraft pulp mill. The use of an acid hydrolysis or a two-step treatment composed of an autohydrolysis followed by a secondary acid hydrolysis was studied. Acid hydrolysis allowed the extraction of higher quantities of sugars but led also to higher degradations of these sugars into inhibitors of fermentation. The direct fermentation of a hydrolysate resulting from an acid hydrolysis gave excellent yields after 24 h. However, the fermentation of hydrolysates after their concentration proved to be impossible. The study of the impact of the inhibitors on the fermentations showed that organic acids, and more specifically formic acid and acetic acid were greatly involved in the inhibition

  19. Improved diffusivity of NaOH solution in autohydrolyzed poplar sapwood chips for chemi-mechanical pulp production. (United States)

    Zhang, Honglei; Hou, Qingxi; Liu, Wei; Yue, Zhen; Jiang, Xiaoya; Ma, Xixi


    This work investigated the changes in the physical structure of autohydrolyzed poplar sapwood chips and the effect on the subsequent alkali liquor diffusion properties for chemi-mechanical pulping (CMP). An alkali impregnation process was conducted by using the autohydrolyzed poplar sapwood with different levels of autohydrolysis intensity. The results showed that the volume porosity, water constraint capacity, and saturated water absorption of the autohydrolyzed poplar sapwood chips increased. Also, the effective capillary cross-sectional area (ECCSA) in the radial direction and the diffusion coefficients of NaOH solution in both the radial and axial directions all increased. Autohydrolysis pretreatment enhanced the alkali liquor diffusion properties in poplar sapwood chips, and the diffusion coefficient was increased more greatly in the radial direction than that in the axial direction. Copyright © 2018 Elsevier Ltd. All rights reserved.

  20. Xylitol Production from Eucalyptus Wood Hydrolysates in Low-Cost Fermentation Media

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    José Diz


    Full Text Available Several aspects concerning the bioconversion of xylose-containing hydrolysates (obtained from Eucalyptus wood into xylitol were assessed. Debaryomyces hansenii yeast strains were adapted to fermentation media (obtained either by prehydrolysis or autohydrolysis- posthydrolysis of wood supplemented with low-cost nutrients. Media containing up to 80 g/L xylose were efficiently fermented when the hydrolysates were detoxified by charcoal adsorption and supplemented with corn steep liquor.

  1. Sulfated oligosaccharide structures, as determined by NMR techniques

    International Nuclear Information System (INIS)

    Noseda, M.D.; Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J.; Cerezo, A.S.


    Carrageenans are sulfated polysaccharides, produced by red seaweeds (Rhodophyta), that have important biological and physico-chemical properties. Using partial autohydrolysis, we obtained sulfated oligosaccharides from a λ-carrageenan (Noseda and Cerezo, 1993). These oligosaccharides are valuable not only for the study of the structures of the parent carrageenans but also for their possible biological activities. In this work we determined the chemical structure of one of the sulfated oligosaccharides using 1D and 2D NMR techniques. (author)

  2. Countercurrent Process for Lignin Separation from Biomass Matrix

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    Kiran Kadam; Ed Lehrburger


    The overall goal of the project was to test the concept of using a twin-screw extruder to conduct autohydrolysis pretreatment of wheat straw in countercurrent fashion, demonstrate in situ solid/liquid separation, and produce a low-lignin cellulose product using ethanol as an extractant. The resultant solid product is suitable for sugar production through enzymatic hydrolysis and for pulp applications. Pilot-scale equipment was used to successfully demonstrate the process both for sugar and pulp applications.

  3. Can Acceptable Pulp be Obtained from Eucalyptus globulus Wood Chips after Hemicellulose Extraction?


    Francisco López; M. Trinidad García; Vicente Mena; J. Mauricio Loaiza; Minerva A. M. Zamudio; Juan C. García


    This study investigates the operating conditions used in the soda-anthraquinone pulping of Eucalyptus globulus wood after autohydrolysis pretreatment on the yield, kappa number, and brightness of the resulting unbleached pulp. Moreover, strength-related properties of the resulting handsheets was examined to identify the best pulping conditions and compare the outcome with that of a conventional soda-anthraquinone pulping process. The paper strength properties of the pulp were similar to or be...

  4. Rapid Mass Spectrometric Analysis of a Novel Fucoidan, Extracted from the Brown Alga Coccophora langsdorfii

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    Stanislav D. Anastyuk


    Full Text Available The novel highly sulfated (35% fucoidan fraction Cf2 , which contained, along with fucose, galactose and traces of xylose and uronic acids was purified from the brown alga Coccophora langsdorfii. Its structural features were predominantly determined (in comparison with fragments of known structure by a rapid mass spectrometric investigation of the low-molecular-weight fragments, obtained by “mild” (5 mg/mL and “exhaustive” (maximal concentration autohydrolysis. Tandem matrix-assisted laser desorption/ionization mass spectra (MALDI-TOF/TOFMS of fucooligosaccharides with even degree of polymerization (DP, obtained by “mild” autohydrolysis, were the same as that observed for fucoidan from Fucus evanescens, which have a backbone of alternating (1 → 3- and (1 → 4 linked sulfated at C-2 and sometimes at C-4 of 3-linked α-L-Fucp residues. Fragmentation patterns of oligosaccharides with odd DP indicated sulfation at C-2 and at C-4 of (1 → 3 linked α-L-Fucp residues on the reducing terminus. Minor sulfation at C-3 was also suggested. The “exhaustive” autohydrolysis allowed us to observe the “mixed” oligosaccharides, built up of fucose/xylose and fucose/galactose. Xylose residues were found to occupy both the reducing and nonreducing termini of FucXyl disaccharides. Nonreducing galactose residues as part of GalFuc disaccharides were found to be linked, possibly, by 2-type of linkage to fucose residues and were found to be sulfated, most likely, at position C-2.

  5. Co-production of electricity and ethanol, process economics of value prior combustion

    International Nuclear Information System (INIS)

    Treasure, T.; Gonzalez, R.; Venditti, R.; Pu, Y.; Jameel, H.; Kelley, S.; Prestemon, Jeffrey


    Highlights: ► Economics of producing cellulosic ethanol and bio-power in the same facility using an autohydrolysis process. ► Feedstock considerably affect the economics of the biorefinery facility. ► Lower moisture content improves financial performance of the bio-power business. - Abstract: A process economic analysis of co-producing bioethanol and electricity (value prior to combustion) from mixed southern hardwood and southern yellow pine is presented. Bioethanol is produced by extracting carbohydrates from wood via autohydrolysis, membrane separation of byproducts, enzymatic hydrolysis of extracted oligomers and fermentation to ethanol. The residual solids after autohydrolysis are pressed and burned in a power boiler to generate steam and electricity. A base case scenario of biomass combustion to produce electricity is presented as a reference to understand the basics of bio-power generation economics. For the base case, minimum electricity revenue of $70–$96/MWh must be realized to achieve a 6–12% internal rate of return. In the alternative co-production cases, the ethanol facility is treated as a separate business entity that purchases power and steam from the biomass power plant. Minimum ethanol revenue required to achieve a 12% internal rate of return was estimated to be $0.84–$1.05/l for hardwood and $0.74–$0.85/l for softwood. Based on current market conditions and an assumed future ethanol selling price of $0.65/l, the co-production of cellulosic bioethanol and power does not produce financeable returns. A risk analysis indicates that there is a probability of 26.6% to achieve an internal rate of return equal or higher than 12%. It is suggested that focus be placed on improving yield and reducing CAPEX before this technology can be applied commercially. This modeling approach is a robust method to evaluate economic feasibility of integrated production of bio-power and other products based on extracted hemicellulose.

  6. Effect of steam pretreatment on oil palm empty fruit bunch for the production of sugars

    International Nuclear Information System (INIS)

    Shamsudin, Saleha; Md Shah, Umi Kalsom; Zainudin, Huzairi; Abd-Aziz, Suraini; Mustapa Kamal, Siti Mazlina; Shirai, Yoshihito; Hassan, Mohd Ali


    Lignocellulose into fuel ethanol is the most feasible conversion route strategy in terms of sustainability. Oil palm empty fruit bunch (EFB) generated from palm oil production is a huge source of cellulosic material and represents a cheap renewable feedstock which awaits further commercial exploitation. The purpose of this study was to investigate the feasibility of using steam at 0.28 MPa and 140 °C generated from the palm oil mill boiler as a pretreatment to enhance the digestibility of EFB for sugars production. The effects of steam pretreatment or autohydrolysis on chemical composition changes, polysaccharide conversion, sugar production and morphology alterations of four different types of EFB namely fresh EFB (EFB1), sterilized EFB (EFB2), shredded EFB (EFB3) and ground EFB (EFB4) were evaluated. In this study, the effects of steam pretreatment showed major alterations in the morphology of EFB as observed under the scanning electron microscope. Steam pretreated EFB2 was found to have the highest total conversion of 30% to sugars with 209 g kg −1 EFB. This production was 10.5 fold higher than for EFB1 and 1.6 fold and 1.7 fold higher than EFB3 and EFB4, respectively. The results suggested that pretreatment of EFB by autohydrolysis using steam from the mill boiler could be considered as being a suitable pretreatment process for the production of sugars. These sugars can be utilized as potential substrates for the production of various products such as fuel ethanol. -- Highlights: ► We investigate the feasibility of steam pretreatment to enhance digestibility of EFB. ► Steam pretreatment increased sugars to 3.4 fold and caused major alteration in EFB morphology under SEM. ► Autohydrolysis which does not require the addition of chemicals is an attractive pretreatment approach to EFB.


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    Carlos Vila,


    Full Text Available To assess the feasibility of implementing hemicellulose recovery stages in kraft mills, Eucalyptus globulus wood samples were subjected to aqueous treatments with hot, compressed water (autohydrolysis processing to achieve partial dissolution of xylan. Autohydrolyzed solids were subjected to kraft pulping under selected conditions to yield a pulp of low kappa number, and to an optimized TCF bleaching sequence made up of three stages (alkaline oxygen delignification, chelating, and pressurized hydrogen peroxide, with minimized additions of pulping and bleaching chemicals. The final product had a relatively low kappa number (1.4, 641 mL/g ISO intrinsic viscosity, and 86.4% brightness.

  8. Sulfated oligosaccharide structures, as determined by NMR techniques

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    Noseda, M.D.; Duarte, M.E.R.; Tischer, C.A.; Gorin, P.A.J. [Parana Univ., Curitiba, PR (Brazil). Dept. De Bioquimica; Cerezo, A.S. [Buenos Aires Univ. Nacional (Argentina). Dept. de Quimica Organica


    Carrageenans are sulfated polysaccharides, produced by red seaweeds (Rhodophyta), that have important biological and physico-chemical properties. Using partial autohydrolysis, we obtained sulfated oligosaccharides from a {lambda}-carrageenan (Noseda and Cerezo, 1993). These oligosaccharides are valuable not only for the study of the structures of the parent carrageenans but also for their possible biological activities. In this work we determined the chemical structure of one of the sulfated oligosaccharides using 1D and 2D NMR techniques. (author) 4 refs., 8 figs., 1 tabs.

  9. Pectic oligosacharides from lemon peel wastes: production, purification, and chemical characterization. (United States)

    Gómez, Belén; Gullón, Beatriz; Yáñez, Remedios; Parajó, Juan C; Alonso, Jose L


    Lemon peel wastes were extracted with water to remove free sugars and other soluble compounds, and the insoluble solid was employed as a substrate for the manufacture of pectin-derived oligosaccharides by processing with hot, compressed water. When water-extracted lemon peel wastes were treated with water at 160 °C, the oligomer concentration reached the maximum value (31 g/L). Autohydrolysis liquors were subjected to two membrane filtration stages (diafiltration followed by concentration), yielding a refined product containing about 98 wt % of oligomers at a global yield of 14 kg/100 kg oven-dry lemon peel. The concentrate contained oligogalacturonides (with DP in the range of 2-18) and arabinooligosaccharides (with DP in the range of 2-8).


    Directory of Open Access Journals (Sweden)

    Anna Ebringerová


    Full Text Available The isolation of non-cellulosic polysaccharides from both almond shells and their solid residue after autohydrolysis using a two-step alkaline extraction without and in combination with short ultrasonic treatment was investigated. The obtained polysaccharide preparations were characterized by yield, chemical composition and structural features, and the antioxidant activity of the water-soluble preparations was discussed in relation to the content of phenolics. The results suggested that, depending on the extraction conditions used, xylan associated to various extent with pectic polysaccharides and phenolics can be prepared, and the reaction time significantly shortened by application of ultrasound. The xylan polymers might serve as biopolymer sources in native form or after targeted modification for production of value-added substances and polysaccharide-based antioxidants, applicable in food, cosmetics and other areas.


    Directory of Open Access Journals (Sweden)

    Joni Tapani Lehto,


    Full Text Available Carbohydrate-containing hydrolysates (1.1 to 14.9% of wood dry matter obtained from autohydrolysis (at 130 to 150°C for 30 to 120 minutes of birch (Betula pendula chips prior to pulping were purified with respect to non-carbohydrate materials, without carbohydrate losses, either by ethyl acetate extraction or XAD-4 resin treatment. In the former case, about 50% of lignin and practically all the furanoic compounds (2-furaldehyde and 5-(hydroxymethylfurfural could be removed, whereas in the latter case, the corresponding amounts were about 30% and 50 to 90%, respectively. A partial recovery of various unsaturated impurities is of importance, because they may act as inhibitors when biochemically converting carbohydrates in hydrolysates into value-added products.

  12. Hydrothermal pretreatment of wood by mild steam explosion and hot water extraction. (United States)

    Wojtasz-Mucha, Joanna; Hasani, Merima; Theliander, Hans


    The aim of this work was to compare the two most common hydrothermal pre-treatments for wood - mild steam explosion and hot water extraction - both with the prospect of enabling extraction of hemicelluloses and facilitating further processing. Although both involve autohydrolysis of the lignocellulosic tissue, they are performed under different conditions: the most prominent difference is the rapid, disintegrating, discharge employed in the steam explosion opening up the structure. In this comparative study, the emphasis was placed on local composition of the pre-treated wood chips (of industrially relevant size). The results show that short hot water extraction treatments lead to significant variations in the local composition within the wood chips, while steam explosion accomplishes a comparably more even removal of hemicelluloses due to the advective mass transport during the explosion step. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Total recovery of the waste of two-phase olive oil processing: isolation of added-value compounds. (United States)

    Fernández-Bolaños, Juan; Rodríguez, Guillermo; Gómez, Esther; Guillén, Rafael; Jiménez, Ana; Heredia, Antonia; Rodríguez, Rocío


    A process for the value addition of solid waste from two-phase olive oil extraction or "alperujo" that includes a hydrothermal treatment has been suggested. In this treatment an autohydrolysis process occurs and the solid olive byproduct is partially solubilized. From this water-soluble fraction can be obtained besides the antioxidant hydroxytyrosol several other compounds of high added value. In this paper three different samples of alperujo were characterized and subjected to a hydrothermal treatment with and without acid catalyst. The main soluble compounds after the hydrolysis were represented by monosaccharides xylose, arabinose, and glucose; oligosaccharides, mannitol and products of sugar destruction. Oligosaccharides were separated by size exclusion chromatography. It was possible to get highly purified mannitol by applying a simple purification method.

  14. Furfural production from biomass pretreatment hydrolysate using vapor-releasing reactor system. (United States)

    Liu, Lu; Chang, Hou-Min; Jameel, Hasan; Park, Sunkyu


    Biomass hydrolysate from autohydrolysis pretreatment was used for furfural production considering it is in rich of xylose, xylo-oligomers, and other decomposition products from hemicellulose structure. By using the vapor-releasing reactor system, furfural was protected from degradation by separating it from the reaction media. The maximum furfural yield of 73% was achieved at 200 °C for biomass hydrolysate without the use of the catalyst. This is because the presence of organic acids such as acetic acid in hydrolysate functioned as a catalyst. According to the results in this study, biomass hydrolysate with a vapor-releasing system proves to be efficient for furfural production. The biorefinery process which allows the separation of xylose-rich autohydrolysate from other parts from biomass feedstock also improves the overall application of the biomass. Copyright © 2018 Elsevier Ltd. All rights reserved.

  15. Microwave irradiation of lignocellulosic materials, 4: Enhancement of enzymatic susceptibility of microwave-irradiated softwoods

    International Nuclear Information System (INIS)

    Azuma, J.; Higashino, J.; Isaka, M.; Koshijima, T.


    Effect of microwave irradiation on the enzymatic susceptibility of various softwoods was investigated. The pH values of the reaction liquor dropped with increasing temperature to 2.9-3.3 at 230°C, consistent with increase in acidity (0.5-0.85 meq at 230-239° C). Above approximately 180°C, hemicellulose underwent acid-mediated autohydrolysis and became water-soluble yielding a mixture of oligosaccharides and monosaccharides. The composition of water-soluble portion was similar for all wood species tested. The maximum extents of saccharification below 240°C ranged between 36-62% for softwoods, while those for hardwoods were between 88-93%. The present investigation confirmed that microwave pretreatment enhanced the enzymatic susceptibility of various softwoods. However, further attempt should be needed to give higher values equal to those for hardwoods. (author)

  16. Innovative pretreatment strategies for biogas production. (United States)

    Patinvoh, Regina J; Osadolor, Osagie A; Chandolias, Konstantinos; Sárvári Horváth, Ilona; Taherzadeh, Mohammad J


    Biogas or biomethane is traditionally produced via anaerobic digestion, or recently by thermochemical or a combination of thermochemical and biological processes via syngas (CO and H 2 ) fermentation. However, many of the feedstocks have recalcitrant structure and are difficult to digest (e.g., lignocelluloses or keratins), or they have toxic compounds (such as fruit flavors or high ammonia content), or not digestible at all (e.g., plastics). To overcome these challenges, innovative strategies for enhanced and economically favorable biogas production were proposed in this review. The strategies considered are commonly known physical pretreatment, rapid decompression, autohydrolysis, acid- or alkali pretreatments, solvents (e.g. for lignin or cellulose) pretreatments or leaching, supercritical, oxidative or biological pretreatments, as well as combined gasification and fermentation, integrated biogas production and pretreatment, innovative biogas digester design, co-digestion, and bio-augmentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Review of pretreatment processes for lignocellulosic ethanol production, and development of an innovative method

    International Nuclear Information System (INIS)

    Chiaramonti, David; Prussi, Matteo; Ferrero, Simone; Oriani, Luis; Ottonello, Piero; Torre, Paolo; Cherchi, Francesco


    Biomass pretreatment aims at separating and providing easier access to the main biomass components (cellulose, hemicellulose and lignin), eventually removing lignin, preserving the hemicellulose, reducing the cellulose crystallinity and increasing the porosity of the material. Pretreatment is an essential step towards the development and industrialization of efficient 2nd generation lignocellulosic ethanol processes. The present work reviewed the main options available in pretreatment. Autohydrolysis and steam explosion were then selected for further investigation. Experimental work was carried out on batch scale reactors, using Miscanthus as biomass feedstock: the effects on sugar solubilization and degradation products generation have been examined for each of these two pretreatment systems. A new process using only water and steam as reacting media was then developed, experimentally tested, and results compared to those achieved by the autohydrolysis and steam explosion processes. Products obtained with the new pretreatment contained a lower amount of usual fermentation inhibitor compounds compared to that typically obtained in steam explosion. This result was achieved under operating conditions that at the same time allowed a good xylan yield, preventing degradation of hemicelluloses. The new pretreatment process was also able to act as an equalization step, as the solid material from the pretreatment phase had a similar composition even under different operating conditions. As regards the effect of pretreatment on enzymatic hydrolysis, the new process achieved yields similar to steam explosion on glucans: however, this was obtained reducing the formation of degradation products from sugars, mainly from C5 sugars. These results made the proposed pretreatment system suitable for further development and industrialization on pilot and industrial scale.

  18. Influence of steaming explosion time on the physic-chemical properties of cellulose from Lespedeza stalks (Lespedeza crytobotrya). (United States)

    Wang, Kun; Jiang, Jian-Xin; Xu, Feng; Sun, Run-Cang


    The synergistic effect of steam explosion pretreatment and sodium hydroxide post-treatment of Lespedeza stalks (Lespedeza crytobotrya) has been investigated in this study. In this case, Lespedeza stalks were firstly exploded at a fixed steam pressure (22.5 kg/m(2)) for 2-10 min. Then the steam-exploded Lespedeza stalks was extracted with 1 M NaOH at 50 degrees C for 3 h with a shrub to water ratio of 1:20 (g/ml), which yielded 57.3%, 53.1%, 55.4%, 52.8%, 53.2%, and 56.4% (% dry weight) cellulose rich fractions, comparing to 68.0% from non-steam-exploded material. The content of glucose in cellulose rich residues increased with increment of the steaming time and reached to 94.10% at the most severity. The similar increasing trend occurred during the dissolution of hemicelluloses. It is evident that at shorter steam explosion time, autohydrolysis mainly occurred on the hemicelluloses and the amorphous area of cellulose. The crystalline region of cellulose was depolymerized under a prolonged incubation time. The characteristics of the cellulose rich fractions in terms of FT-IR and CP/MAS (13)C NMR spectroscopy and thermal analysis were discussed, and the surface structure was also investigated by SEM.

  19. Efficient acetone-butanol-ethanol production by Clostridium beijerinckii from sugar beet pulp. (United States)

    Bellido, Carolina; Infante, Celia; Coca, Mónica; González-Benito, Gerardo; Lucas, Susana; García-Cubero, María Teresa


    Sugar beet pulp (SBP) has been investigated as a promising feedstock for ABE fermentation by Clostridium beijerinckii. Although lignin content in SBP is low, a pretreatment is needed to enhance enzymatic hydrolysis and fermentation yields. Autohydrolysis at pH 4 has been selected as the best pretreatment for SBP in terms of sugars release and acetone and butanol production. The best overall sugars release yields from raw SBP ranged from 66.2% to 70.6% for this pretreatment. The highest ABE yield achieved was 0.4g/g (5.1g/L of acetone and 6.6g/L butanol) and 143.2g ABE/kg SBP (62.3g acetone and 80.9g butanol) were obtained when pretreated SBP was enzymatically hydrolyzed at 7.5% (w/w) solid loading. Higher solid loadings (10%) offered higher acetone and butanol titers (5.8g/L of acetone and 7.8g/L butanol). All the experiments were carried out under not-controlling pH conditions reaching about 5.3 in the final samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Acetate adaptation of clostridia tyrobutyricum for improved fermentation production of butyrate. (United States)

    Jaros, Adam M; Rova, Ulrika; Berglund, Kris A


    Clostridium tyrobutyricum ATCC 25755 is an acidogenic bacterium capable of utilizing xylose for the fermentation production of butyrate. Hot water extraction of hardwood lingocellulose is an efficient method of producing xylose where autohydrolysis of xylan is catalysed by acetate originating from acetyl groups present in hemicellulose. The presence of acetic acid in the hydrolysate might have a severe impact on the subsequent fermentations. In this study the fermentation kinetics of C. tyrobutyricum cultures after being classically adapted for growth at 26.3 g/L acetate equivalents were studied. Analysis of xylose batch fermentations found that even in the presence of high levels of acetate, acetate adapted strains had similar fermentation kinetics as the parental strain cultivated without acetate. The parental strain exposed to acetate at inhibitory conditions demonstrated a pronounced lag phase (over 100 hours) in growth and butyrate production as compared to the adapted strain (25 hour lag) or non-inhibited controls (0 lag). Additional insight into the metabolic pathway of xylose consumption was gained by determining the specific activity of the acetate kinase (AK) enzyme in adapted versus control batches. AK activity was reduced by 63% in the presence of inhibitory levels of acetate, whether or not the culture had been adapted.

  1. Material and energy balances in the production of ethanol from wood

    Energy Technology Data Exchange (ETDEWEB)

    Wayman, M; Lora, J H; Gulbinas, E


    Experimental production of ethanol from aspen wood gave yeilds of 70.7% or 83.4% or theory when acid hydrolysis or enzymatic hydrolysis weere used after autohydrolysis and extraction of lignin. These were, respectively, 58.4 and 68.9 gallons of 95% ethanol per ton of aspen wood (dry basis). In addition 426 lb of lignin with heat of combustion 11,100 Btu/lb were obtained per ton of wood. Gross energy recovery (ethanol + lignin) was 52.4 and 58.0% by thee two processes, or allowing for processing energy, net energy recovery was 36.1 and 42.3% respectively. Multi stage hydrolysis was beneficial for both acid and enzymatic hydrolysis, 80% and over 99% of theoretical yeilds of sugar being obtained by the two processes. Economic estimates show a significant advantage in investment and operating costs for the enzymatic process. Thee price of 95% ethanol, including a reasonable return on investment by this process is estimated at $1.34/gallon. This would be a good price for industrial ethanol, but would be quite high for gasoline use under prevailing circumstance.

  2. Evaluation of hydrogen and methane production from sugarcane bagasse hemicellulose hydrolysates by two-stage anaerobic digestion process. (United States)

    Baêta, Bruno Eduardo Lobo; Lima, Diego Roberto Sousa; Filho, José Gabriel Balena; Adarme, Oscar Fernando Herrera; Gurgel, Leandro Vinícius Alves; Aquino, Sérgio Francisco de


    This study aimed at optimizing the net energy recovery from hydrogen and methane production through anaerobic digestion of the hemicellulose hydrolysate (HH) obtained by desirable conditions (DC) of autohydrolysis pretreatment (AH) of sugarcane bagasse (SB). Anaerobic digestion was carried out in a two-stage (acidogenic-methanogenic) batch system where the acidogenic phase worked as a hydrolysis and biodetoxification step. This allowed the utilization of more severe AH pretreatment conditions, i.e. T=178.6°C and t=55min (DC3) and T=182.9°C and t=40.71min (DC4). Such severe conditions resulted in higher extraction of hemicelluloses from SB (DC1=68.07%, DC2=48.99%, DC3=77.40% and DC4=73.90%), which consequently improved the net energy balance of the proposed process. The estimated energy from the combustion of both biogases (H2 and CH4) accumulated during the two-stage anaerobic digestion of HH generated by DC4 condition was capable of producing a net energy of 3.15MJ·kgSB(-1)dry weight. Copyright © 2016 Elsevier Ltd. All rights reserved.

  3. Enhancement of amylase production by Aspergillus sp. using carbohydrates mixtures from triticale

    Directory of Open Access Journals (Sweden)

    Dojnov Biljana


    Full Text Available For the purpose of finding a suitable available inducer in combination with starvation, carbohydrate mixtures from triticale was used as inducers and compared with well-known amylase inducers in fungi. Carbohydrate mixtures from triticale induced production of amylase cocktail (α-amylase and glucoamylase in Aspergillus niger, unlike induction with well-known inducers which induce only glucoamylase, showed by zymogram and TLC analysis of carbohydrates mixtures before and after fermentations. Glucoamylase production by A. niger was highest in the presence of extract obtained after autohydrolysis of starch from triticale (95.88 U/mL. Carbohydrate mixtures from triticale induced production of α-amylase in A. oryzae. More α-amylase isoforms were detected upon using complex carbohydrate mixture, compared to induction with maltose or starch. The 48 h induction was the most efficient by using triticale extract (101.35 U/mL. Carbohydrates from triticale extracts can be used as very good cheap amylase inducers. Triticale, still not fully utilized, could be taken into consideration as the inducer in amylase production by Aspergillus sp, such a way it could be used as sole substrate in fermentation. [Projekat Ministarstva nauke Republike Srbije, br. 172048

  4. Production and Characterization of Organic Solvent-Tolerant Cellulase from Bacillus amyloliquefaciens AK9 Isolated from Hot Spring. (United States)

    Irfan, Muhammad; Tayyab, Ammara; Hasan, Fariha; Khan, Samiullah; Badshah, Malik; Shah, Aamer Ali


    A cellulase-producing bacterium, designated as strain AK9, was isolated from a hot spring of Tatta Pani, Azad Kashmir, Pakistan. The bacterium was identified as Bacillus amyloliquefaciens through 16S rRNA sequencing. Cellulase from strain AK9 was able to liberate glucose from soluble cellulose and carboxymethyl cellulose (CMC). Enzyme was purified through size exclusion chromatography and a single band of ∼47 kDa was observed on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme was purified with recovery of 35.5%, 3.6-fold purity with specific activity of 31 U mg -1 . The purified cellulase retained its activity over a wide range of temperature (50-70 °C) and pH (3-7) with maximum stability at 60 °C and pH 5.0. The activity inhibited by ethylenediaminetetraacetic acid (EDTA), suggested that it was metalloenzyme. Diethyl pyrocarbonate (DEPC) and β-mercaptoethanol significantly inhibited cellulase activity that revealed the essentiality of histidine residues and disulfide bonds for its catalytic function. It was stable in non-ionic surfactants, in the presence of various metal ions, and in water-insoluble organic solvents. Approximately 9.1% of reducing sugar was released after enzymatic saccharification of DAP-pretreated agro-residue, compared to a very low percentage by autohydrolysis treatment. Hence, it is concluded that cellulase from B. amyloliquefaciens AK9 can potentially be used in bioconversion of lignocellulosic biomass to fermentable sugars.

  5. Comparative biochemical analysis after steam pretreatment of lignocellulosic agricultural waste biomass from Williams Cavendish banana plant (Triploid Musa AAA group). (United States)

    Kamdem, Irénée; Jacquet, Nicolas; Tiappi, Florian Mathias; Hiligsmann, Serge; Vanderghem, Caroline; Richel, Aurore; Jacques, Philippe; Thonart, Philippe


    The accessibility of fermentable substrates to enzymes is a limiting factor for the efficient bioconversion of agricultural wastes in the context of sustainable development. This paper presents the results of a biochemical analysis performed on six combined morphological parts of Williams Cavendish Lignocellulosic Biomass (WCLB) after steam cracking (SC) and steam explosion (SE) pretreatments. Solid (S) and liquid (L) fractions (Fs) obtained from SC pretreatment performed at 180°C (SLFSC180) and 210°C (SLFSC210) generated, after diluted acid hydrolysis, the highest proportions of neutral sugar (NS) contents, specifically 52.82 ± 3.51 and 49.78 ± 1.39%w/w WCLB dry matter (DM), respectively. The highest proportions of glucose were found in SFSC210 (53.56 ± 1.33%w/w DM) and SFSC180 (44.47 ± 0.00%w/w DM), while the lowest was found in unpretreated WCLB (22.70 ± 0.71%w/w DM). Total NS content assessed in each LF immediately after SC and SE pretreatments was less than 2%w/w of the LF DM, thus revealing minor acid autohydrolysis consequently leading to minor NS production during the steam pretreatment. WCLB subjected to SC at 210 °C (SC210) generated up to 2.7-fold bioaccessible glucan and xylan. SC and SE pretreatments showed potential for the deconstruction of WCLB (delignification, depolymerization, decrystallization and deacetylation), enhancing its enzymatic hydrolysis. The concentrations of enzymatic inhibitors, such as 2-furfuraldehyde and 5-(hydroxymethyl)furfural from LFSC210, were the highest (41 and 21 µg ml(-1), respectively). This study shows that steam pretreatments in general and SC210 in particular are required for efficient bioconversion of WCLB. Yet, biotransformation through biochemical processes (e.g., anaerobic digestion) must be performed to assess the efficiency of these pretreatments. © The Author(s) 2015.

  6. Production of lactic acid from hemicellulose extracts by Bacillus coagulans MXL-9. (United States)

    Walton, Sara L; Bischoff, Kenneth M; van Heiningen, Adriaan R P; van Walsum, G Peter


    Bacillus coagulans MXL-9 was found capable of growing on pre-pulping hemicellulose extracts, utilizing all of the principle monosugars found in woody biomass. This organism is a moderate thermophile isolated from compost for its pentose-utilizing capabilities. It was found to have high tolerance for inhibitors such as acetic acid and sodium, which are present in pre-pulping hemicellulose extracts. Fermentation of 20 g/l xylose in the presence of 30 g/l acetic acid required a longer lag phase but overall lactic acid yield was not diminished. Similarly, fermentation of xylose in the presence of 20 g/l sodium increased the lag time but did not affect overall product yield, though 30 g/l sodium proved completely inhibitory. Fermentation of hot water-extracted Siberian larch containing 45 g/l total monosaccharides, mainly galactose and arabinose, produced 33 g/l lactic acid in 60 h and completely consumed all sugars. Small amounts of co-products were formed, including acetic acid, formic acid, and ethanol. Hemicellulose extract formed during autohydrolysis of mixed hardwoods contained mainly xylose and was converted into lactic acid with a 94% yield. Green liquor-extracted hardwood hemicellulose containing 10 g/l acetic acid and 6 g/l sodium was also completely converted into lactic acid at a 72% yield. The Bacillus coagulans MXL-9 strain was found to be well suited to production of lactic acid from lignocellulosic biomass due to its compatibility with conditions favorable to industrial enzymes and its ability to withstand inhibitors while rapidly consuming all pentose and hexose sugars of interest at high product yields.

  7. Partial Purification and Characterization of a Thermostable β-Mannanase from Aspergillus foetidus

    Directory of Open Access Journals (Sweden)

    Juliana da Conceição Infante de Marco


    Full Text Available An extracellular β-mannanase was isolated from samples of crude extract of the mesophilic fungus Aspergillus foetidus grown on soybean husk as a carbon source. The induction profile showed that β-mannanase reached a maximum activity level (2.0 IU/mL on the 15th day of cultivation. The enzyme was partially purified by ultrafiltration and gel filtration chromatography procedures and was named Man 58. Sodium dodecyl sulfate-polyacrilamide electrophoresis and zymogram analysis of Man 58 showed two bands of approximately 43 and 45 kDa with β-mannanase activity. Ultrafiltration showed that β-mannanase activity was only detected in the concentrated sample. Man 58 was most active at 60 °C and at pH 4.0. It was thermostable in the temperature range of 40–60 °C for eleven days, and the half-life at 70 °C was ten days. Man 58 showed Km and Vmax values of 3.29 mg/mL and 1.76 IU/mL respectively, with locust bean gum as a substrate. It was mostly activated by FeSO4 and CoCl2 and inhibited by MgSO4, FeCl3, CuSO4, MgCl2, ZnCl2, ZnSO4, CaCl2, CuCl2, KCl and ethylenediaminetetraacetic acid (EDTA. Phenolic compounds did not inhibit the enzyme. On the other hand, auto-hydrolysis liquor showed an inhibitory effect on Man 58 activity.

  8. DOEGO85004_1: Final Non-proprietary Technical Report, Generating Process and Economic Data for Preliminary Design of PureVision Biorefineries DOEGO85004_2: One Original Final Proprietary Technical Report to be mailed to DOE Golden.

    Energy Technology Data Exchange (ETDEWEB)

    Kadam, Kiran L., Ph.D; Lehrburger, Ed


    The overall objective of the project was to define a two-stage reactive fractionation process for converting corn stover into a solid cellulose stream and two liquid streams containing mostly hemicellulosic sugars and lignin, respectively. Toward this goal, biomass fractionation was conducted using a small continuous pilot unit with a nominal capacity of 100 pounds per day of dry biomass to generate performance data using primarily corn stover as feedstock. In the course of the program, the PureVision process was optimized for efficient hemicellulose hydrolysis in the first stage employing autohydrolysis and delignification in the second stage using sodium hydroxide as a catalyst. The remaining cellulose was deemed to be an excellent substrate for producing fermentation sugars, requiring 40% less enzymes for hydrolysis than conventional pretreatment systems using dilute acid. The fractionated cellulose was also determined to have potential higher-value applications as a pulp product. The lignin coproduct was determined to be substantially lower in molecular weight (MW) compared to lignins produced in the kraft or sulfite pulping processes. This low-MW lignin can be used as a feed and concrete binder and as an intermediate for producing a range of high-value products including phenolic resins. This research adds to the understanding of the biomass conversion area in that a new process was developed in the true spirit of biorefineries. The work completed successfully demonstrated the technical effectiveness of the process at the pilot level indicating the technology is ready to advance to a 2–3 ton per day scale. No technical showstoppers are anticipated in scaling up the PureVision fractionation process to commercial scale. Also, economic feasibility of using the PureVision process in a commercial-scale biorefinery was investigated and the minimum ethanol selling price for the PureVision process was calculated to be $0.94/gal ethanol vs. $1.07/gal ethanol for the