An evaluation of dilute acid and ammonia fiber explosion pretreatment for cellulosic ethanol production.

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Mathew, Anil Kuruvilla; Parameshwaran, Binod; Sukumaran, Rajeev Kumar; Pandey, Ashok

2016-01-01

The challenge associated with cellulosic ethanol production is maximizing sugar yield at low cost. Current research is being focused to develop a pretreatment method to overcome biomass recalcitrance in an efficient way. This review is focused on two major pretreatments: dilute acid (DA) and ammonia fiber explosion (AFEX) pretreatment of corn stover and how these pretreatment cause morphological and chemical changes to corn stover in order to overcome the biomass recalcitrance. This review highlights the key differences of these two pretreatments based on compositional analysis, cellulose and its crystallinity, morphological changes, structural changes to lignin, enzymatic reactivity and enzyme adsorption onto pretreated solids and finally cellulosic ethanol production from the hydrolysate of DA and AFEX treated corn stover. Each stage of the process, AFEX pretreated corn stover was superior to DA treated corn stover. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of Pre-treatment method on the Hydrolysis of Corn cob and Sawdust

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Olawole Ogirima Olanipekun

2016-12-01

Full Text Available Efficient pre-treatment has been found to be crucial step before enzymatic hydrolysis of cellulose into fuels or chemicals. As a result various pretreatment methods have been developed to facilitate these bio-conversion processes, and this research focuses on the effect of two pretreatment methods such as liquid hot water and sulphuric acid pre-treatment to remove some of the components like lignin and hemicellulose which form structural barrier to enzymatic accessibility of cellulose in corn cobs and sawdust. The cellulosic materials were first dried in oven at 65 oC for 24 hours,  and using   solid to liquid ratio of 1:10, the two methods were carried out at resident times ranging from 10 - 40 minutes. The liquid hot water method involved heating the cellulosic materials in water at 120 oC and 1atmosphere in a pressure vessel, and for the second method, the dried cellulosic materials were refluxed in 5 % sulphuric acid at a temperature of 120 oC. Pretreated samples were filtered and liquid fractions were analyzed for the presence of reducing sugars, while solid residues were dried in the oven and weighed to measure the mass lost during pretreatment as a pointer to lignin breakdown. It was observed that the mass lost increased with time for both pretreatment methods, but the liquid hot water pretreatment gave higher lignin and hemicellulose removal when compared to the sulphuric acid pre-treatment. The pretreated materials were hydrolyzed with two combinations of commercial enzymes namely cellulase/ hemicellulase and cellulase/β glucosidase. The reducing sugar was measured using Dinitrosalycilic acid (DNSA method and the sugar yields from corn cobs were higher than that of sawdust when subjected to similar process conditions, and the enzyme combination of cellulase/glucosidase gave higher yields of reducing sugars.  A model equation which describes the hydrolysis process was developed from first principles and the experimental data

Corn stover lignin is modified differently by acetic acid compared to sulfuric acid

NARCIS (Netherlands)

Mouthier, Thibaut; Appeldoorn, Maaike M.; Pel, Herman; Schols, Henk A.; Gruppen, Harry; Kabel, Mirjam A.

2018-01-01

In this study, two acid catalysts, acetic acid (HAc) and sulfuric acid (H2SO4), were compared in thermal pretreatments of corn stover, in particular to assess the less understood fate of lignin. HAc-insoluble lignin, analyzed by pyrolysis GC–MS, showed decreasing levels (%) of Cα-oxidized (from 3.7

The pretreatment of corn stover with Gloeophyllum trabeum KU-41 for enzymatic hydrolysis

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Gao Ziqing

2012-05-01

Full Text Available Abstract Background Pretreatment is an essential step in the enzymatic hydrolysis of biomass for bio-ethanol production. The dominant concern in this step is how to decrease the high cost of pretreatment while achieving a high sugar yield. Fungal pretreatment of biomass was previously reported to be effective, with the advantage of having a low energy requirement and requiring no application of additional chemicals. In this work, Gloeophyllum trabeum KU-41 was chosen for corn stover pretreatment through screening with 40 strains of wood-rot fungi. The objective of the current work is to find out which characteristics of corn stover pretreated with G. trabeum KU-41 determine the pretreatment method to be successful and worthwhile to apply. This will be done by determining the lignin content, structural carbohydrate, cellulose crystallinity, initial adsorption capacity of cellulase and specific surface area of pretreated corn stover. Results The content of xylan in pretreated corn stover was decreased by 43% in comparison to the untreated corn stover. The initial cellulase adsorption capacity and the specific surface area of corn stover pretreated with G. trabeum were increased by 7.0- and 2.5-fold, respectively. Also there was little increase in the cellulose crystallinity of pretreated corn stover. Conclusion G. trabeum has an efficient degradation system, and the results indicated that the conversion of cellulose to glucose increases as the accessibility of cellulose increases due to the partial removal of xylan and the structure breakage of the cell wall. This pretreatment method can be further explored as an alternative to the thermochemical pretreatment method.

Enhancing the enzymatic hydrolysis of corn stover by an integrated wet-milling and alkali pretreatment.

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He, Xun; Miao, Yelian; Jiang, Xuejian; Xu, Zidong; Ouyang, Pingkai

2010-04-01

An integrated wet-milling and alkali pretreatment was applied to corn stover prior to enzymatic hydrolysis. The effects of NaOH concentration in the pretreatment on crystalline structure, chemical composition, and reducing-sugar yield of corn stover were investigated, and the mechanism of increasing reducing-sugar yield by the pretreatment was discussed. The experimental results showed that the crystalline structure of corn stover was disrupted, and lignin was removed, while cellulose and hemicellulose were retained in corn stover by the pretreatment with 1% NaOH in 1 h. The reducing-sugar yield from the pretreated corn stovers increased from 20.2% to 46.7% when the NaOH concentration increased from 0% to 1%. The 1% NaOH pretreated corn stover had a holocellulose conversion of 55.1%. The increase in reducing-sugar yield was related to the crystalline structure disruption and delignification of corn stover. It was clarified that the pretreatment significantly enhanced the conversion of cellulose and hemicellulose in the corn stover to sugars.

Performance and techno-economic assessment of several solid-liquid separation technologies for processing dilute-acid pretreated corn stover.

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Sievers, David A; Tao, Ling; Schell, Daniel J

2014-09-01

Solid-liquid separation of pretreated lignocellulosic biomass slurries is a critical unit operation employed in several different processes for production of fuels and chemicals. An effective separation process achieves good recovery of solute (sugars) and efficient dewatering of the biomass slurry. Dilute acid pretreated corn stover slurries were subjected to pressure and vacuum filtration and basket centrifugation to evaluate the technical and economic merits of these technologies. Experimental performance results were used to perform detailed process simulations and economic analysis using a 2000 tonne/day biorefinery model to determine differences between the various filtration methods and their process settings. The filtration processes were able to successfully separate pretreated slurries into liquor and solid fractions with estimated sugar recoveries of at least 95% using a cake washing process. A continuous vacuum belt filter produced the most favorable process economics. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of pretreatment severity on accumulation of major degradation products from dilute acid pretreated corn stover and subsequent inhibition of enzymatic hydrolysis of cellulose.

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Um, Byung-Hwan; van Walsum, G Peter

2012-09-01

The concept of reaction severity, which combines residence time and temperature, is often used in the pulp and paper and biorefining industries. The influence of corn stover pretreatment severity on yield of sugar and major degradation products and subsequent effects on enzymatic cellulose hydrolysis was investigated. The pretreatment residence time and temperature, combined into the severity factor (Log R(o)), were varied with constant acid concentration. With increasing severity, increasing concentrations of furfural and 5-hydroxymethylfurfural (5-HMF) coincided with decreasing yields of oligosaccharides. With further increase in severity factor, the concentrations of furans decreased, while the formation of formic acid and lactic acid increased. For example, from severity 3.87 to 4.32, xylose decreased from 6.39 to 5.26 mg/mL, while furfural increased from 1.04 to 1.33 mg/mL; as the severity was further increased to 4.42, furfural diminished to 1.23 mg/mL as formate rose from 0.62 to 1.83 mg/mL. The effects of dilute acid hydrolyzate, acetic acid, and lignin, in particular, on enzymatic hydrolysis were investigated with a rapid microassay method. The microplate method gave considerable time and cost savings compared to the traditional assay protocol, and it is applicable to a broad range of lignocellulosic substrates.

Microbial pretreatment of corn stovers by solid-state cultivation of Phanerochaete chrysosporium for biogas production.

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Liu, Shan; Wu, Shubiao; Pang, Changle; Li, Wei; Dong, Renjie

2014-02-01

The microbial pretreatment of corn stover and corn stover silage was achieved via the solid-state cultivation of Phanerochaete chrysosporium; pretreatment effects on the biodegradability and subsequent anaerobic production of biogas were investigated. The peak levels of daily biogas production and CH₄ yield from corn stover silage were approximately twice that of corn stover. Results suggested that ensiling was a potential pretreatment method to stimulate biogas production from corn stover. Surface morphology and Fourier-transform infrared spectroscopy analyses demonstrated that the microbial pretreatment of corn stover silage improved biogas production by 10.5 to 19.7% and CH4 yield by 11.7 to 21.2% because pretreatment could decrease dry mass loss (14.2%) and increase substrate biodegradability (19.9% cellulose, 32.4% hemicellulose, and 22.6% lignin). By contrast, the higher dry mass loss in corn stover (55.3%) after microbial pretreatment was accompanied by 54.7% cellulose, 64.0% hemicellulose, and 61.1% lignin degradation but did not significantly influence biogas production.

Cellulose conversion of corn pericarp without pretreatment.

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Kim, Daehwan; Orrego, David; Ximenes, Eduardo A; Ladisch, Michael R

2017-12-01

We report enzyme hydrolysis of cellulose in unpretreated pericarp at a cellulase loading of 0.25FPU/g pericarp solids using a phenol tolerant Aspergillus niger pectinase preparation. The overall protein added was 5mg/g and gave 98% cellulose conversion in 72h. However, for double the amount of enzyme from Trichoderma reesei, which is significantly less tolerant to phenols, conversion was only 16%. The key to achieving high conversion without pretreatment is combining phenol inhibition-resistant enzymes (such as from A. niger) with unground pericarp from which release of phenols is minimal. Size reduction of the pericarp, which is typically carried out in a corn-to-ethanol process, where corn is first ground to a fine powder, causes release of highly inhibitory phenols that interfere with cellulase enzyme activity. This work demonstrates hydrolysis without pretreatment of large particulate pericarp is a viable pathway for directly producing cellulose ethanol in corn ethanol plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

The impacts of pretreatment on the fermentability of pretreated lignocellulosic biomass: a comparative evaluation between ammonia fiber expansion and dilute acid pretreatment

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Dale Bruce E

2009-12-01

Full Text Available Abstract Background Pretreatment chemistry is of central importance due to its impacts on cellulosic biomass processing and biofuels conversion. Ammonia fiber expansion (AFEX and dilute acid are two promising pretreatments using alkaline and acidic pH that have distinctive differences in pretreatment chemistries. Results Comparative evaluation on these two pretreatments reveal that (i AFEX-pretreated corn stover is significantly more fermentable with respect to cell growth and sugar consumption, (ii both pretreatments can achieve more than 80% of total sugar yield in the enzymatic hydrolysis of washed pretreated solids, and (iii while AFEX completely preserves plant carbohydrates, dilute acid pretreatment at 5% solids loading degrades 13% of xylose to byproducts. Conclusion The selection of pretreatment will determine the biomass-processing configuration, requirements for hydrolysate conditioning (if any and fermentation strategy. Through dilute acid pretreatment, the need for hemicellulase in biomass processing is negligible. AFEX-centered cellulosic technology can alleviate fermentation costs through reducing inoculum size and practically eliminating nutrient costs during bioconversion. However, AFEX requires supplemental xylanases as well as cellulase activity. As for long-term sustainability, AFEX has greater potential to diversify products from a cellulosic biorefinery due to lower levels of inhibitor generation and lignin loss.

Evaluation of soluble fraction and enzymatic residual fraction of dilute dry acid, ethylenediamine, and steam explosion pretreated corn stover on the enzymatic hydrolysis of cellulose.

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Qin, Lei; Liu, Li; Li, Wen-Chao; Zhu, Jia-Qing; Li, Bing-Zhi; Yuan, Ying-Jin

2016-06-01

This study is aimed to examine the inhibition of soluble fraction (SF) and enzymatic residual fraction (ERF) in dry dilute acid (DDA), ethylenediamine (EDA) and steam explosion (SE) pretreated corn stover (CS) on the enzymatic digestibility of cellulose. SF of DDA, EDA and SE pretreated CS has high xylose, soluble lignin and xylo-oligomer content, respectively. SF of EDA pretreated CS leads to the highest inhibition, followed by SE and DDA pretreated CS. Inhibition of ERF of DDA and SE pretreated CS is higher than that of EDA pretreated CS. The inhibition degree (A0/A) of SF is 1.76 and 1.21 times to that of ERF for EDA and SE pretreated CS, respectively. The inhibition degree of ERF is 1.05 times to that of SF in DDA pretreated CS. The quantitative analysis shows that SF of EDA pretreated CS, SF and ERF of SE pretreated CS cause significant inhibition during enzymatic hydrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermogravimetric kinetics of corn stalk pretreated by oleaginous fungi Cunninghamella echinulata.

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Wu, Jianguo; Gao, Shi; Wan, Jilin; Zeng, Yelin; Ma, Fuying; Zhang, Xiaoyu

2011-04-01

The thermogravimetric and composition of corn stalk pretreated by oleaginous fungi Cunninghamella echinulata had been studied in this paper. Results indicated that pretreatment by oleaginous fungi C. echinulata could decrease the activation energy and make the pyrolysis more efficient and energy-saving. By bio-pretreatment, the contents of elements agreed with the weight loss, sugar content, and oil contents, especially the sulfur content was greatly decreased, greatly eliminating the inventory of gas contamination such as the emission of SOx and making the pyrolysis more environmentally friendly. Therefore, corn stalk with sugar pretreated by oleaginous fungi C. echinulata should be a good pyrolysis material to obtain high quality bio-oil. Copyright © 2011 Elsevier Ltd. All rights reserved.

Understanding of alkaline pretreatment parameters for corn stover enzymatic saccharification

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Chen Ye

2013-01-01

Full Text Available Abstract Background Previous research on alkaline pretreatment has mainly focused on optimization of the process parameters to improve substrate digestibility. To achieve satisfactory sugar yield, extremely high chemical loading and enzyme dosages were typically used. Relatively little attention has been paid to reduction of chemical consumption and process waste management, which has proven to be an indispensable component of the bio-refineries. To indicate alkali strength, both alkali concentration in pretreatment solution (g alkali/g pretreatment liquor or g alkali/L pretreatment liquor and alkali loading based on biomass solids (g alkali/g dry biomass have been widely used. The dual approaches make it difficult to compare the chemical consumption in different process scenarios while evaluating the cost effectiveness of this pretreatment technology. The current work addresses these issues through pretreatment of corn stover at various combinations of pretreatment conditions. Enzymatic hydrolysis with different enzyme blends was subsequently performed to identify the effects of pretreatment parameters on substrate digestibility as well as process operational and capital costs. Results The results showed that sodium hydroxide loading is the most dominant variable for enzymatic digestibility. To reach 70% glucan conversion while avoiding extensive degradation of hemicellulose, approximately 0.08 g NaOH/g corn stover was required. It was also concluded that alkali loading based on total solids (g NaOH/g dry biomass governs the pretreatment efficiency. Supplementing cellulase with accessory enzymes such as α-arabinofuranosidase and β-xylosidase significantly improved the conversion of the hemicellulose by 6–17%. Conclusions The current work presents the impact of alkaline pretreatment parameters on the enzymatic hydrolysis of corn stover as well as the process operational and capital investment costs. The high chemical consumption for alkaline

Comparative study of sulfite pretreatments for robust enzymatic saccharification of corn cob residue

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Bu Lingxi

2012-12-01

Full Text Available Abstract Background Corn cob residue (CCR is a kind of waste lignocellulosic material with enormous potential for bioethanol production. The moderated sulphite processes were used to enhance the hydrophily of the material by sulfonation and hydrolysis. The composition, FT-IR spectra, and conductometric titrations of the pretreated materials were measured to characterize variations of the CCR in different sulfite pretreated environments. And the objective of this study is to compare the saccharification rate and yield of the samples caused by these variations. Results It was found that the lignin in the CCR (43.2% had reduced to 37.8%, 38.0%, 35.9%, and 35.5% after the sulfite pretreatment in neutral, acidic, alkaline, and ethanol environments, respectively. The sulfite pretreatments enhanced the glucose yield of the CCR. Moreover, the ethanol sulfite sample had the highest glucose yield (81.2%, based on the cellulose in the treated sample among the saccharification samples, which was over 10% higher than that of the raw material (70.6%. More sulfonic groups and weak acid groups were produced during the sulfite pretreatments. Meanwhile, the ethanol sulfite treated sample had the highest sulfonic group (0.103 mmol/g and weak acid groups (1.85 mmol/g in all sulfite treated samples. In FT-IR spectra, the variation of bands at 1168 and 1190 cm-1 confirmed lignin sulfonation during sulfite pretreatment. The disappearance of the band at 1458 cm-1 implied the methoxyl on lignin had been removed during the sulfite pretreatments. Conclusions It can be concluded that the lignin in the CCR can be degraded and sulfonated during the sulfite pretreatments. The pretreatments improve the hydrophility of the samples because of the increase in sulfonic group and weak acid groups, which enhances the glucose yield of the material. The ethanol sulfite pretreatment is the best method for lignin removal and with the highest glucose yield.

Enhanced glucose yield and structural characterization of corn stover by sodium carbonate pretreatment.

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Kim, Ilgook; Rehman, Muhammad Saif Ur; Han, Jong-In

2014-01-01

Na2CO3 was employed as an efficient yet cheap alkaline catalyst for the pretreatment of corn stover. To systematically obtain an optimal condition, the effects of critical pretreatment parameters including Na2CO3 concentration (2-6%), temperature (120-160 °C), and reaction time (10-30 min) on glucose yield were evaluated in lab-scale using response surface methodology. The best conditions were found to be Na2CO3 of 4.1%, temperature of 142.6 °C, and reaction time of 18.0 min, under which glucose yield reached to 267.5 g/kg biomass. Physical properties, based on scanning electron microscopy (SEM) imagery, surface area, pore volume and size, and crystallinity of pretreated corn stover, were examined. The Na2CO3 pretreatment apparently damaged the surface and altered structural features of corn stover, which resulted in the enhancement of enzymatic of hydrolysis. These results evidently support that Na2CO3 is indeed a robust and feasible catalyst for pretreating lignocellulosic biomass. Copyright © 2013 Elsevier Ltd. All rights reserved.

Pretreatment of corn stover using wet oxidation to enhance enzymatic digestibility.

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Varga, Eniko; Schmidt, Anette S; Réczey, Kati; Thomsen, Anne Belinda

2003-01-01

Corn stover is an abundant, promising raw material for fuel ethanol production. Although it has a high cellulose content, without pretreatment it resists enzymatic hydrolysis, like most lignocellulosic materials. Wet oxidation (water, oxygen, mild alkali or acid, elevated temperature and pressure) was investigated to enhance the enzymatic digestibility of corn stover. Six different combinations of reaction temperature, time, and pH were applied. The best conditions (60 g/L of corn stover, 195 degrees C, 15 min, 12 bar O2, 2 g/L of Na2CO3) increased the enzymatic conversion of corn stover four times, compared to untreated material. Under these conditions 60% of hemicellulose and 30% of lignin were solubilized, whereas 90% of cellulose remained in the solid fraction. After 24-h hydrolysis at 50 degrees C using 25 filter paper units (FPU)/g of drymatter (DM) biomass, the achieved conversion of cellulose to glucose was about 85%. Decreasing the hydrolysis temperature to 40 degrees C increased hydrolysis time from 24 to 72 h. Decreasing the enzyme loading to 5 FPU/g of DM biomass slightly decreased the enzymatic conversion from 83.4 to 71%. Thus, enzyme loading can be reduced without significantly affecting the efficiency of hydrolysis, an important economical aspect.

Lower pressure heating steam is practical for the distributed dry dilute sulfuric acid pretreatment.

Science.gov (United States)

Shao, Shuai; Zhang, Jian; Hou, Weiliang; Qureshi, Abdul Sattar; Bao, Jie

2017-08-01

Most studies paid more attention to the pretreatment temperature and the resulted pretreatment efficiency, while ignored the heating media and their scalability to an industry scale. This study aimed to use a relative low pressure heating steam easily provided by steam boiler to meet the requirement of distributed dry dilute acid pretreatment. The results showed that the physical properties of the pretreated corn stover were maintained stable using the steam pressure varying from 1.5, 1.7, 1.9 to 2.1MPa. Enzymatic hydrolysis and high solids loading simultaneous saccharification and fermentation (SSF) results were also satisfying. CFD simulation indicated that the high injection velocity of the low pressure steam resulted in a high steam holdup and made the mixing time of steam and solid corn stover during pretreatment much shorter in comparison with the higher pressure steam. This study provides a design basis for the boiler requirement in distributed pretreatment concept. Copyright © 2017 Elsevier Ltd. All rights reserved.

Fast and efficient nanoshear hybrid alkaline pretreatment of corn stover for biofuel and materials production

International Nuclear Information System (INIS)

Wang, Wei; Ji, Shaowen; Lee, Ilsoon

2013-01-01

We report a fast and efficient nano-scale shear hybrid alkaline (NSHA) pretreatment method of lignocellulosic biomass. In this work, corn stover was pretreated in a modified Taylor–Couette reactor with alkali (sodium hydroxide) at room temperature for two minutes. Up to 82% of high cellulose content in the remaining solids was achieved with the novel NSHA pretreatment process. Compared with untreated corn stover, an approximately 4-fold increase in enzymatic cellulose conversion and a 5-fold increase in hemicellulose conversion were achieved. Compositional analysis proved significant removals of both lignin and hemicellulose after the NSHA pretreatment. SEM images revealed that the synergistic effect of NSHA pretreatment caused the severe disruption of biomass structure and exposure of cellulose microfibril aggregates in NSHA pretreated corn stover. Highlights: ► A fast nanoshear hybrid alkaline (NSHA) pretreatment method is reported. ► A modified Taylor–Couette reactor was applied. ► The retention time of the NSHA method is only 2 min. ► A 100% conversion of glucan was achieved in one day. ► NSHA greatly removed both lignin and xylan

Acid hydrolysis of corn stover using hydrochloric acid: Kinetic modeling and statistical optimization

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Sun Yong

2014-01-01

Full Text Available The hydrolysis of corn stover using hydrochloric acid was studied. The kinetic parameters of the mathematical models for predicting the yields of xylose, glucose, furfural and acetic acid were obtained, and the corresponding xylose generation activation energy of 100 kJ/mol was determined. The characterization of corn stover using with different techniques during hydrolysis indicated an effective removal of xylan and the slightly alteration on the structures of cellulose and lignin. A 23five levels Central Composite Design (CCD was used to develop a statistical model for the optimization of process variables including acid concentration, pretreatment temperature and time. The optimum conditions determined by this model were found to be 108ºC for 80 minutes with acid concentration of 5.8%. Under these conditions, the maximised results are the following: xylose 19.93 g/L, glucose 1.2 g/L, furfural 1.5 g/L, acetic acid 1.3 g/L. The validation of the model indicates a good agreement between the experimental results and the predicted values.

Effect of xylan and lignin removal by batch and flowthrough pretreatment on the enzymatic digestibility of corn stover cellulose.

Science.gov (United States)

Yang, Bin; Wyman, Charles E

2004-04-05

Compared with batch systems, flowthrough and countercurrent reactors have important potential advantages for pretreating cellulosic biomass, including higher hemicellulose sugar yields, enhanced cellulose digestibility, and reduced chemical additions. Unfortunately, they suffer from high water and energy use. To better understand these trade-offs, comparative data are reported on xylan and lignin removal and enzymatic digestibility of cellulose for corn stover pretreated in batch and flowthrough reactors over a range of flow rates between 160 degrees and 220 degrees C, with water only and also with 0.1 wt% sulfuric acid. Increasing flow with just water enhanced the xylan dissolution rate, more than doubled total lignin removal, and increased cellulose digestibility. Furthermore, adding dilute sulfuric acid increased the rate of xylan removal for both batch and flowthrough systems. Interestingly, adding acid also increased the lignin removal rate with flow, but less lignin was left in solution when acid was added in batch. Although the enzymatic hydrolysis of pretreated cellulose was related to xylan removal, as others have shown, the digestibility was much better for flowthrough compared with batch systems, for the same degree of xylan removal. Cellulose digestibility for flowthrough reactors was related to lignin removal as well. These results suggest that altering lignin also affects the enzymatic digestibility of corn stover. Copyright 2004 Wiley Periodicals, Inc.

Mild alkaline presoaking and organosolv pretreatment of corn stover and their impacts on corn stover composition, structure, and digestibility.

Science.gov (United States)

Qing, Qing; Zhou, Linlin; Guo, Qi; Gao, Xiaohang; Zhang, Yan; He, Yucai; Zhang, Yue

2017-06-01

An efficient strategy was developed in current work for biochemical conversion of carbohydrates of corn stover into monosaccharides. Corn stover was first presoaked in mild alkaline solution (1% Na 2 S) under 40°C for 4h, after which about 35.3% of the lignin was successfully removed while the specific surface area was notably enlarged. Then the presoaked solids were subjected to organosolv pretreatment that employed 20% methanol with an addition of 0.2% HCl as catalyst at 160°C for 20min, and the maximum total sugar yield of the pretreated corn stover achieved was 98.6%. The intact structure of corn stover was disrupted by this two-step process, which resulted in a porous but crystalline structure of the regenerated solids that were mainly composed of cellulose. The enlarged specific surface area and increased accessibility made the regenerated solids highly digestible by a moderate enzyme loading. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of ultrasonic and CO₂laser pretreatment methods on enzyme digestibility of corn stover.

Science.gov (United States)

Tian, Shuang-Qi; Wang, Zhen-Yu; Fan, Zi-Luan; Zuo, Li-Li

2012-01-01

To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO(2) laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO(2) laser irradiation. The present work demonstrated that the CO(2) laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO(2) laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO(2) laser pretreatment on corn stover to be more effective than ultrasonic pretreatment.

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

DEFF Research Database (Denmark)

Georgieva, Tania I.; Ahring, Birgitte Kiær

2007-01-01

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...

Ethanol production from hydrothermal pretreated corn stover with a loop reactor

Energy Technology Data Exchange (ETDEWEB)

Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda [National Lab for Sustainable Energy, Biosystems Department, Risoe-DTU, P.O. Box 49, DK-4000 Roskilde (Denmark)

2010-03-15

Hydrothermal pretreatment on raw corn stover (RCS) with a loop reactor was investigated at 195 C for different times varying between 10 min and 30 min. After pretreatment, the slurry was separated into water-insoluble solid (WIS) and liquid phase. Glucan and xylan were found in the both phases. The pretreatment condition showed a significant impact on xylan recovery. As the pretreatment time prolonged from 10 min to 30 min, the xylan recovery from liquid phase changed between 39.5% and 45.6% and the total xylan recoveries decreased from 84.7% to 61.6%. While the glucan recovery seemed not sensitive to the different pretreatment times. The glucan recovered from liquid was from 4.9% to 5.6% and the total glucan recoveries from all the pretreatments were higher than 98%. Besides HMF and furfural, acetic, lactic, formic and glycolic acids were also found in the liquid phase. All the concentrations of these potential inhibitors were lower enough not to affect the activity of the Saccharomyces cerevisiae (S. cerevisiae). Compared with the ethanol production of 32.4% from the RCS with S. cerevisiae, all the WISs gave higher ethanol productions ranging between 61.2% and 71.2%. When the xylan was taken into consideration, the best pretreatment condition would be 195 C, 15 min and the estimated total ethanol production was 201 g kg{sup -1} RCS by assuming the fermentation of both C-6 and C-5 with the ethanol yield of 0.51 g g{sup -1} and 0.47 g g{sup -1}, respectively. (author)

Ethanol production from hydrothermal pretreated corn stover with a loop reactor

International Nuclear Information System (INIS)

Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

2010-01-01

Hydrothermal pretreatment on raw corn stover (RCS) with a loop reactor was investigated at 195 o C for different times varying between 10 min and 30 min. After pretreatment, the slurry was separated into water-insoluble solid (WIS) and liquid phase. Glucan and xylan were found in the both phases. The pretreatment condition showed a significant impact on xylan recovery. As the pretreatment time prolonged from 10 min to 30 min, the xylan recovery from liquid phase changed between 39.5% and 45.6% and the total xylan recoveries decreased from 84.7% to 61.6%. While the glucan recovery seemed not sensitive to the different pretreatment times. The glucan recovered from liquid was from 4.9% to 5.6% and the total glucan recoveries from all the pretreatments were higher than 98%. Besides HMF and furfural, acetic, lactic, formic and glycolic acids were also found in the liquid phase. All the concentrations of these potential inhibitors were lower enough not to affect the activity of the Saccharomyces cerevisiae (S. cerevisiae). Compared with the ethanol production of 32.4% from the RCS with S. cerevisiae, all the WISs gave higher ethanol productions ranging between 61.2% and 71.2%. When the xylan was taken into consideration, the best pretreatment condition would be 195 o C, 15 min and the estimated total ethanol production was 201 g kg -1 RCS by assuming the fermentation of both C-6 and C-5 with the ethanol yield of 0.51 g g -1 and 0.47 g g -1 , respectively.

Utilization of microwave and ultrasound pretreatments in the production of bioethanol from corn

Energy Technology Data Exchange (ETDEWEB)

Nikolic, Svetlana; Mojovic, Ljiljana; Rakin, Marica [University of Belgrade, Faculty of Technology and Metallurgy, Belgrade (Serbia); Pejin, Dusanka; Pejin, Jelena [University of Novi Sad, Faculty of Technology, Novi Sad (Serbia)

2011-08-15

Bioethanol production by simultaneous saccharification and fermentation (SSF) of corn meal by Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system with prior ultrasound or microwave treatment was studied. The optimal duration of the pretreatments and the SSF process kinetics were assessed and determined. Also, the effect of ultrasound and microwave pretreatments on ethanol yield and productivity was investigated. An optimal duration of 5 min was determined for both pretreatments. Ultrasonic and microwave pretreatments effectively increased the glucose concentration obtained after liquefaction by 6.82 and 8.48%, respectively, compared to untreated control sample. Also, both pretreatments improved ethanol yield and productivity during the SSF process. Ultrasound and microwave pretreatments increased the maximum ethanol concentration produced in the SSF process by 11.15 and 13.40% (compared to the control sample), respectively. The application of microwave pretreatment resulted in higher glucose release during liquefaction and consequently in higher ethanol concentration, compared to ultrasound pretreatment. A maximum ethanol concentration of 9.91% (w/w) and percentage of theoretical ethanol yield of 92.27% were achieved after 44 h of the SSF process of corn meal with prior microwave treatment. (orig.)

Corn stover for biogas production: Effect of steam explosion pretreatment on the gas yields and on the biodegradation kinetics of the primary structural compounds.

Science.gov (United States)

Lizasoain, Javier; Trulea, Adrian; Gittinger, Johannes; Kral, Iris; Piringer, Gerhard; Schedl, Andreas; Nilsen, Paal J; Potthast, Antje; Gronauer, Andreas; Bauer, Alexander

2017-11-01

This study evaluated the effect of steam explosion on the chemical composition and biomethane potential of corn stover using temperatures ranging between 140 and 220°C and pretreatment times ranging between 2 and 15min. Biodegradation kinetics during the anaerobic digestion of untreated and corn stover, pretreated at two different intensities, 140°C for 5min and 180°C for 5min, were studied in tandem. Results showed that pretreatment at 160°C for 2min improved the methane yield by 22%. Harsher pretreatment conditions led to lower hemicellulose contents and methane yields, as well as higher lignin contents, which may be due to the formation of pseudo-lignin. The biodegradation kinetics trial demonstrated that steam explosion enhances the degradation of structural carbohydrates and acid insoluble lignin. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of enzymatic hydrolysis and ultrasounds pretreatments on corn cob and vine trimming shoots for biogas production.

Science.gov (United States)

Pérez-Rodríguez, N; García-Bernet, D; Domínguez, J M

2016-12-01

Due to their lignocellulosic nature, corn cob and vine trimming shoots (VTS) could be valorized by anaerobic digestion for biogas production. To enhance the digestibility of substrates, pretreatments of lignocellulosic materials are recommended. The effect of enzymatic hydrolysis, ultrasounds pretreatments (US) and the combination of both was assayed in lignocellulosic composition, methane, and biogas yields. The pretreatments leaded to a reduction in lignin and an increase in neutral detergent soluble compounds making corn cob and VTS more amendable for biogas conversion. The US were negative for biogas production from both substrates and in particular strongly detrimental for VTS. On the opposite side, the enzymatic hydrolysis was certainly beneficial increasing 59.8% and 14.6% the methane production from VTS and corn cob, respectively. The prior application of US did not potentiate (or not sufficiently) the improvement in the methane production reflected by the enzymatic hydrolysis pretreatment of VTS and corn cob. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of the Effects of Thermal Pretreatment, Steam Explosion and Ultrasonic Disintegration on Digestibility of Corn Stover

Directory of Open Access Journals (Sweden)

Andras Dallos

2016-06-01

Full Text Available The energy demand of the corn-based bioethanol production could be reduced using the agricultural byproducts as bioenergy feedstock for biogas digesters. The release of lignocellulosic material and therefore the acceleration of degradation processes can be achieved using thermal and mechanical pretreatments, which assist to hydrolyze the cell walls and speed the solubilization of biopolymers in biogas feedstock. This study is focused on liquid hot water, steam explosion and ultrasonic pretreatments of corn stover. The scientific contribution of this paper is a comprehensive comparison of the performance of the pretreatments by fast analytical, biochemical, anaerobic digestibility and biomethane potential tests, extended by energy consumptions and energy balance calculations.The effectiveness of pretreatments was evaluated by means of soluble chemical oxygen demand, biochemical oxygen demand and by the biogas and methane productivities. The results have shown that the thermal pretreatment, steam explosion and ultrasonic irradiation of biogas feedstock disintegrated the lignocellulosic structure, increased and accelerated the methane production and increased the cumulative biogas and methane productivity of corn stover in reference to the control during mesophilic anaerobic digestion.The energy balance demonstrated that there is an economical basis of the application of the liquid hot-compressed water pretreatments in a biogas plant. However, the steam explosion and ultrasonication are energetically not profitable for corn stover pretreatment.

Comparison of Ultrasonic and CO2 Laser Pretreatment Methods on Enzyme Digestibility of Corn Stover

Directory of Open Access Journals (Sweden)

Li-Li Zuo

2012-03-01

Full Text Available To decrease the cost of bioethanol production, biomass recalcitrance needs to be overcome so that the conversion of biomass to bioethanol becomes more efficient. CO2 laser irradiation can disrupt the lignocellulosic physical structure and reduce the average size of fiber. Analyses with Fourier transform infrared spectroscopy, specific surface area, and the microstructure of corn stover were used to elucidate the enhancement mechanism of the pretreatment process by CO2 laser irradiation. The present work demonstrated that the CO2 laser had potential to enhance the bioconversion efficiency of lignocellulosic waste to renewable bioethanol. The saccharification rate of the CO2 laser pretreatment was significantly higher than ultrasonic pretreatment, and reached 27.75% which was 1.34-fold of that of ultrasonic pretreatment. The results showed the impact of CO2 laser pretreatment on corn stover to be more effective than ultrasonic pretreatment.

Process Design and Economics for Biochemical Conversion of Lignocellulosic Biomass to Ethanol: Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover

Energy Technology Data Exchange (ETDEWEB)

Humbird, D.; Davis, R.; Tao, L.; Kinchin, C.; Hsu, D.; Aden, A.; Schoen, P.; Lukas, J.; Olthof, B.; Worley, M.; Sexton, D.; Dudgeon, D.

2011-03-01

This report describes one potential biochemical ethanol conversion process, conceptually based upon core conversion and process integration research at NREL. The overarching process design converts corn stover to ethanol by dilute-acid pretreatment, enzymatic saccharification, and co-fermentation. Building on design reports published in 2002 and 1999, NREL, together with the subcontractor Harris Group Inc., performed a complete review of the process design and economic model for the biomass-to-ethanol process. This update reflects NREL's current vision of the biochemical ethanol process and includes the latest research in the conversion areas (pretreatment, conditioning, saccharification, and fermentation), optimizations in product recovery, and our latest understanding of the ethanol plant's back end (wastewater and utilities). The conceptual design presented here reports ethanol production economics as determined by 2012 conversion targets and 'nth-plant' project costs and financing. For the biorefinery described here, processing 2,205 dry ton/day at 76% theoretical ethanol yield (79 gal/dry ton), the ethanol selling price is $2.15/gal in 2007$.

Rapid near infrared spectroscopy for prediction of enzymatic hydrolysis of corn bran after various pretreatments

DEFF Research Database (Denmark)

Baum, Andreas; Wittrup Agger, Jane; Meyer, Anne S.

2012-01-01

Efficient generation of a fermentable hydrolysate is a primary requirement in the utilization of fibrous plant biomass as feedstocks in bioethanol processes. The first biomass conversion step usually involves a hydrothermal pretreatment before enzymatic hydrolysis. The purpose of the pretreatment...... step is to increase the responsivity of the substrate to enzymatic attack and the type of pretreatment affects the enzymatic conversion efficiency. Destarched corn bran is a fibrous, heteroxylan-rich side-stream from the starch industry which may be used as a feedstock for bioethanol production...... release of different levels of arabinose, xylose and glucose from all the differently pretreated destarched corn bran samples. The present study also demonstrates a generic, non-destructive solution to determine the enzymatic monosaccharide release from polymers in biomass side-streams, thereby...

Integrated Production of Xylonic Acid and Bioethanol from Acid-Catalyzed Steam-Exploded Corn Stover.

Science.gov (United States)

Zhu, Junjun; Rong, Yayun; Yang, Jinlong; Zhou, Xin; Xu, Yong; Zhang, Lingling; Chen, Jiahui; Yong, Qiang; Yu, Shiyuan

2015-07-01

High-efficiency xylose utilization is one of the restrictive factors of bioethanol industrialization. However, xylonic acid (XA) as a new bio-based platform chemical can be produced by oxidation of xylose with microbial. So, an applicable technology of XA bioconversion was integrated into the process of bioethanol production. After corn stover was pretreated with acid-catalyzed steam-explosion, solid and liquid fractions were obtained. The liquid fraction, also named as acid-catalyzed steam-exploded corn stover (ASC) prehydrolyzate (mainly containing xylose), was catalyzed with Gluconobacter oxydans NL71 to prepare XA. After 72 h of bioconversion of concentrated ASC prehydrolyzate (containing 55.0 g/L of xylose), the XA concentration reached a peak value of 54.97 g/L, the sugar utilization ratio and XA yield were 94.08 and 95.45 %, respectively. The solid fraction was hydrolyzed to produce glucose with cellulase and then fermented with Saccharomyces cerevisiae NL22 to produce ethanol. After 18 h of fermentation of concentrated enzymatic hydrolyzate (containing 86.22 g/L of glucose), the ethanol concentration reached its highest value of 41.48 g/L, the sugar utilization ratio and ethanol yield were 98.72 and 95.25 %, respectively. The mass balance showed that 1 t ethanol and 1.3 t XA were produced from 7.8 t oven dry corn stover.

Recycling the liquid fraction of alkaline hydrogen peroxide in the pretreatment of corn stover.

Science.gov (United States)

Alencar, Bárbara Ribeiro Alves; Reis, Alexandre Libanio Silva; de Souza, Raquel de Fatima Rodrigues; Morais, Marcos Antônio; Menezes, Rômulo Simões Cezar; Dutra, Emmanuel Damilano

2017-10-01

The aim of this study was to evaluate the influence of recycling the liquid fraction of pretreatment with alkaline hydrogen peroxide (AHP) on the hydrolysis of corn stover. Corn stover was pretreated in the traditional condition with 7.5% v/v H 2 O 2 . After pretreatment, the solids were separated from the liquid fraction and five successive reuse cycles of the liquid fraction were tested. The solid fraction from pretreatment in each recycle was submitted to enzymatic hydrolysis. The number of recycles had a linear negative effect (R 2 =0.98) on biomass delignification efficiency and also affected negatively the enzymatic conversion efficiency. Despite the decrease in efficiency after each recycling step, reuse of the liquid fraction leads to reduction in water, H 2 O 2 and NaOH consumption of up to 57.6%, 59.6% and 57.6%, respectively. These findings point to an efficient recycling technology, which may reduce costs and save water. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lactic Acid Production from Pretreated Hydrolysates of Corn Stover by a Newly Developed Bacillus coagulans Strain

OpenAIRE

Jiang, Ting; Qiao, Hui; Zheng, Zhaojuan; Chu, Qiulu; Li, Xin; Yong, Qiang; Ouyang, Jia

2016-01-01

An inhibitor-tolerance strain, Bacillus coagulans GKN316, was developed through atmospheric and room temperature plasma (ARTP) mutation and evolution experiment in condensed dilute-acid hydrolysate (CDH) of corn stover. The fermentabilities of other hydrolysates with B. coagulans GKN316 and the parental strain B. coagulans NL01 were assessed. When using condensed acid-catalyzed steam-exploded hydrolysate (CASEH), condensed acid-catalyzed liquid hot water hydrolysate (CALH) and condensed acid-...

High titer L-lactic acid production from corn stover with minimum wastewater generation and techno-economic evaluation based on Aspen plus modeling.

Science.gov (United States)

Liu, Gang; Sun, Jiaoe; Zhang, Jian; Tu, Yi; Bao, Jie

2015-12-01

Technological potentials of l-lactic acid production from corn stover feedstock were investigated by experimental and techno-economic studies. An optimal performance with 104.5 g/L in l-lactic acid titer and 71.5% in overall yield from cellulose in corn stover to l-lactic acid using an engineered Pediococcus acidilactici strain were obtained by overcoming several technical barriers. A rigorous Aspen plus model for l-lactic acid production starting from dry dilute acid pretreated and biodetoxified corn stover was developed. The techno-economic analysis shows that the minimum l-lactic acid selling price (MLSP) was $0.523 per kg, which was close to that of the commercial l-lactic acid produced from starch feedstock, and 24% less expensive than that of ethanol from corn stover, even though the xylose utilization was not considered. The study provided a prototype of industrial application and an evaluation model for high titer l-lactic acid production from lignocellulose feedstock. Copyright © 2015 Elsevier Ltd. All rights reserved.

Ultrasonic pretreatment for enhanced saccharification and fermentation of ethanol production from corn

Science.gov (United States)

Montalbo-Lomboy, Melissa T.

The 21st Century human lifestyle has become heavily dependent on hydrocarbon inputs. Energy demand and the global warming effects due to the burning of fossil fuels have continued to increase. Rising awareness of the negative environmental and economic impacts of hydrocarbon dependence has led to a resurgence of interest in renewable energy sources such as ethanol. Fuel ethanol is known to be a cleaner and renewable source of energy relative to gasoline. Many studies have agreed that fuel ethanol has reduced greenhouse gas (GHG) emissions and has larger overall energy benefits compared to gasoline. Currently, the majority of the fuel ethanol in the United States is produced from corn using dry-grind milling process. The typical dry-grind ethanol plant incorporates jet cooking using steam to cook the corn slurry as pretreatment for saccharification; an energy intensive step. In aiming to reduce energy usage, this study evaluated the use of ultrasonics as an alternative to jet cooking. Ultrasonic batch experiments were conducted using a Branson 2000 Series bench-scale ultrasonic unit operating at a frequency of 20 kHz and a maximum output of 2.2 kW. Corn slurry was sonicated at varying amplitudes from 192 to 320 mumpeak-to-peak(p-p) for 0-40 seconds. Enzyme stability was investigated by adding enzyme (STARGEN(TM)001) before and after sonication. Scanning electron micrograph (SEM) images and particle size distribution analysis showed a nearly 20-fold size reduction by disintegration of corn particles due to ultrasonication. The results also showed a 30% improvement in sugar release of sonicated samples relative to the control group (untreated). The efficiency exceeded 100% in terms of relative energy gain from the additional sugar released due to ultrasonication compared to the ultrasonic energy applied. Interestingly, enzymatic activity was enhanced when sonicated at low and medium power. This result suggested that ultrasonic energy did not denature the enzymes

Enhancing biogas production of corn stover by fast pyrolysis pretreatment.

Science.gov (United States)

Wang, Fang; Zhang, Deli; Wu, Houkai; Yi, Weiming; Fu, Peng; Li, Yongjun; Li, Zhihe

2016-10-01

A new thermo-chemical pretreatment by a lower temperature fast pyrolysis (LTFP) was applied to promote anaerobic digestion (AD) efficiency of corn stover (CS). The pretreatment experiment was performed by a fluidized bed pyrolysis reactor at 180, 200 and 220°C with a carrier gas flow rate of 4 and 3m(3)/h. The components characteristics, Scanning Electron Microscope (SEM) images and Crystal Intensity (CrI) of the pretreated CS were tested to explore effectiveness of the pretreatment. The results showed that the cumulative methane production at 180°C for 4 and 3m(3)/h were 199.8 and 200.3mL/g TS, respectively. As compared to the untreated CS, the LTFP pretreatment significantly (a<0.05) increased the methane production by 18.07% and 18.33%, respectively. Methane production was well fitted by the Gompertz models, and the maximum methane potential and AD efficiency was obtained at 180°C for 3m(3)/h. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cost Effective Bioethanol via Acid Pretreatment of Corn Stover, Saccharification, and Conversion via a Novel Fermentation Organism: Cooperative Research and Development Final Report, CRADA Number: CRD-12-485

Energy Technology Data Exchange (ETDEWEB)

Dowe, N.

2014-05-01

This research program will convert acid pretreated corn stover to sugars at the National Renewable Energy Laboratory (NREL) and then transfer these sugars to Honda R&D and its partner the Green Earth Institute (GEI) for conversion to ethanol via a novel fermentation organism. In phase one, NREL will adapt its pretreatment and saccharification process to the unique attributes of this organism, and Honda R&D/GEI will increase the sugar conversion rate as well as the yield and titer of the resulting ethanol. In later phases, NREL, Honda R&D, and GEI will work together at NREL to optimize and scale-up to pilot-scale the Honda R&D/GEI bioethanol production process. The final stage will be to undertake a pilot-scale test at NREL of the optimized bioethanol conversion process.

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

Directory of Open Access Journals (Sweden)

Wei Hui

2011-11-01

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.

High-concentration sugars production from corn stover based on combined pretreatments and fed-batch process.

Science.gov (United States)

Yang, Maohua; Li, Wangliang; Liu, Binbin; Li, Qiang; Xing, Jianmin

2010-07-01

In this paper, high-concentration sugars were produced from pretreated corn stover. The raw corn stover was pretreated in a process combining steam explosion and alkaline hydrogen-peroxide. The hemicellulose and lignin were removed greatly. The cellulose content increased to 73.2%. Fed-batch enzymatic hydrolysis was initiated with 12% (w/v) solids loading and 20 FPU/g solids. Then, 6% solids were fed consecutively at 12, 36 and 60 h. After 144 h, the final concentrations of reducing sugar, glucose, cellobiose and xylose reached 220, 175, 22 and 20 g/L, respectively. The final total biomass conversion was 60% in fed-batch process. Copyright 2009 Elsevier Ltd. All rights reserved.

PRETREATMENT AND FRACTIONATION OF CORN STOVER BY AMMONIA RECYCLE PERCOLATION PROCESS. (R831645)

Science.gov (United States)

Corn stover was pretreated with aqueous ammonia in a flow-through column reactor,a process termed as Ammonia Recycle Percolation (ARP). The aqueous ammonia causesswelling and efficient delignification of biomass at high temperatures. The ARPprocess solubilizes abou...

Enzymatic hydrolysis of corn bran arabinoxylan

DEFF Research Database (Denmark)

Agger, Jane

as a model substrate because it represents a readily available agroindustrial side product with upgrading potentials. Corn bran originates from the wet-milling process in corn starch processing, is the outmost layers of the corn kernel and is particularly rich in pentose monosaccharides comprising the major...... in a complex and ridig cell wall structure. This thesis contains a thorough examination of the monosaccharide and structural composition of corn bran, which is used to assess and apply the relevant mono component enzyme preparations. In this way, the aim is to obtain the most effective minimal enzymatic......, especially with respect to xylose and glucose release, but vast amounts of the valuable monosaccharides are lost during this pretreatment and this is especially evident for arabinose. From a scientific point of view acid catalysed pretreatment renders the substrate in a state of disruption where assessment...

Enhanced Enzymatic Hydrolysis and Structural Features of Corn Stover by NaOH and Ozone Combined Pretreatment

Directory of Open Access Journals (Sweden)

Wenhui Wang

2018-05-01

Full Text Available A two-step pretreatment using NaOH and ozone was performed to improve the enzymatic hydrolysis, compositions and structural characteristics of corn stover. Comparison between the unpretreated and pretreated corn stover was also made to illustrate the mechanism of the combined pretreatment. A pretreatment with 2% (w/w NaOH at 80 °C for 2 h followed by ozone treatment for 25 min with an initial pH 9 was found to be the optimal procedure and the maximum efficiency (91.73% of cellulose enzymatic hydrolysis was achieved. Furthermore, microscopic observation of changes in the surface structure of the samples showed that holes were formed and lignin and hemicellulose were partially dissolved and removed. X-ray Diffraction (XRD, Fourier Transform Infrared Spectroscopy (FTIR and Cross-Polarization Magic Angle Spinning Carbon-13 Nuclear Magnetic Resonance (CP/MAS 13C-NMR were also used to characterize the chemical structural changes after the combined pretreatment. The results were as follows: part of the cellulose I structure was destroyed and then reformed into cellulose III, the cellulose crystal indices were also changed; a wider space between the crystal layer was observed; disruption of hydrogen bonds in cellulose and disruption of ester bonds in hemicellulose; cleavage of bonds linkage in lignin-carbohydrate complexes; removal of methoxy in lignin and hemicellulose. As a result, all these changes effectively reduced recalcitrance of corn stover and promoted subsequent enzymatic hydrolysis of cellulose.

Promoting anaerobic biogasification of corn stover through biological pretreatment by liquid fraction of digestate (LFD).

Science.gov (United States)

Hu, Yun; Pang, Yunzhi; Yuan, Hairong; Zou, Dexun; Liu, Yanping; Zhu, Baoning; Chufo, Wachemo Akiber; Jaffar, Muhammad; Li, Xiujin

2015-01-01

A new biological pretreatment method by using liquid fraction of digestate (LFD) was advanced for promoting anaerobic biogasification efficiency of corn stover. 17.6% TS content and ambient temperature was appropriate for pretreatment. The results showed that C/N ratio decreased to about 30, while total lignin, cellulose, and hemicellulose (LCH) contents were reduced by 8.1-19.4% after pretreatment. 3-days pretreatment was considered to be optimal, resulting in 70.4% more biogas production, 66.3% more biomethane yield and 41.7% shorter technical digestion time compared with the untreated stover. The reductions on VS, cellulose, and hemicellulose were increased by 22.1-35.9%, 22.3-35.4%, and 19.8-27.2% for LFD-treated stovers. The promoted anaerobic biogasification efficiency was mainly attributed to the improved biodegradability due to the pre-decomposition role of the bacteria in LFD. The method proved to be an efficient and low cost approach for producing bioenergy from corn stover, meanwhile, reducing LFD discharge and minimizing its potential pollution. Copyright © 2014 Elsevier Ltd. All rights reserved.

Conditioning of dilute-acid pretreated corn stover hydrolysate liquors by treatment with lime or ammonium hydroxide to improve conversion of sugars to ethanol.

Science.gov (United States)

Jennings, Edward W; Schell, Daniel J

2011-01-01

Dilute-acid pretreatment of lignocellulosic biomass enhances the ability of enzymes to hydrolyze cellulose to glucose, but produces many toxic compounds that inhibit fermentation of sugars to ethanol. The objective of this study was to compare the effectiveness of treating hydrolysate liquor with Ca(OH)2 and NH4OH for improving ethanol yields. Corn stover was pretreated in a pilot-scale reactor and then the liquor fraction (hydrolysate) was extracted and treated with various amounts of Ca(OH)2 or NH4OH at several temperatures. Glucose and xylose in the treated liquor were fermented to ethanol using a glucose-xylose fermenting bacteria, Zymomonas mobilis 8b. Sugar losses up to 10% occurred during treatment with Ca(OH)2, but these losses were two to fourfold lower with NH4OH treatment. Ethanol yields for NH4OH-treated hydrolysate were 33% greater than those achieved in Ca(OH)2-treated hydrolysate and pH adjustment to either 6.0 or 8.5 with NH4OH prior to fermentation produced equivalent ethanol yields. Copyright © 2010 Elsevier Ltd. All rights reserved.

Succinic acid production from acid hydrolysate of corn fiber by Actinobacillus succinogenes.

Science.gov (United States)

Chen, Kequan; Jiang, Min; Wei, Ping; Yao, Jiaming; Wu, Hao

2010-01-01

Dilute acid hydrolysate of corn fiber was used as carbon source for the production of succinic acid by Actinobacillus succinogenes NJ113. The optimized hydrolysis conditions were obtained by orthogonal experiments. When corn fiber particles were of 20 mesh in size and treated with 1.0% sulfuric acid at 121 degrees C for 2 h, the total sugar yield could reach 63.3%. It was found that CaCO(3) neutralization combined with activated carbon adsorption was an effective method to remove fermentation inhibitors especially furfural that presented in the acid hydrolysate of corn fiber. Only 5.2% of the total sugar was lost, while 91.9% of furfural was removed. The yield of succinic acid was higher than 72.0% with the detoxified corn fiber hydrolysate as the carbon source in anaerobic bottles or 7.5 L fermentor cultures. It was proved that the corn fiber hydrolysate could be an alternative to glucose for the production of succinic acid by A. succinogenes NJ113.

Bioconversion of corn stover hydrolysate to ethanol by a recombinant yeast strain

Energy Technology Data Exchange (ETDEWEB)

Zhao, Jing; Xia, Liming

2010-12-15

Three corn stover hydrolysates, enzymatic hydrolysates prepared from acid and alkaline pretreatments separately and hemicellulosic hydrolysate prepared from acid pretreatment, were evaluated in composition and fermentability. For enzymatic hydrolysate from alkaline pretreatment, ethanol yield on fermentable sugars and fermentation efficiency reached highest among the three hydrolysates; meanwhile, ethanol yield on dry corn stover reached 0.175 g/g, higher than the sum of those of two hydrolysates from acid pretreatment. Fermentation process of the enzymatic hydrolysate from alkaline pretreatment was further investigated using free and immobilized cells of recombinant Saccharomyces cerevisiae ZU-10. Concentrated hydrolysate containing 66.9 g/L glucose and 32.1 g/L xylose was utilized. In the fermentation with free cells, 41.2 g/L ethanol was obtained within 72 h with an ethanol yield on fermentable sugars of 0.416 g/g. Immobilized cells greatly enhanced the ethanol productivity, while the ethanol yield on fermentable sugars of 0.411 g/g could still be reached. Repeated batch fermentation with immobilized cells was further attempted up to six batches. The ethanol yield on fermentable sugars maintained above 0.403 g/g with all glucose and more than 92.83% xylose utilized in each batch. These results demonstrate the feasibility and efficiency of ethanol production from corn stover hydrolysates. (author)

Fermentative hydrogen production from pretreated biomass: A comparative study

NARCIS (Netherlands)

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

2009-01-01

The aim of this work was to evaluate the potential of employing biomass resources from different origin as feedstocks for fermentative hydrogen production. Mild-acid pretreated and hydrolysed barley straw (BS) and corn stalk (CS), hydrolysed barley grains (BG) and corn grains (CG), and sugar beet

Effect of irradiation, as a pretreatment, on bioconversion of corn stover into protein-rich mycelial biomass of Pleurotus sajor-caju

International Nuclear Information System (INIS)

Awafo, V.A.; Chahal, D.S.; Charbonneau, R.

1995-01-01

Application of irradiation for food preservation, for pretreatment of lignocellulosic materials for their hydrolysis and to increase the digestibility of lignocellulosic materials for rumen animals have been reported in the literature. In the present study, irradiation (100 KGy to 1.7 MGy) of corn stover as a pretreatment to make it susceptible for its bioconversion into protein-rich mycelial biomass of Pleurotus sajor-caju NRRL 18757 has been compared with that of mild alkali treatment (0.01 to 0.15 g NaOH/g corn stover), the most commonly used pretreatment. Protein synthesis increased with the increase in doses of irradiation as well as with the increase in concentration of NaOH. Combination pretreatment with NaOH and γ-irradiation reduced the quantity of NaOH and doses of irradiation required to get optimum yields of protein indicating a strong synergistic effect. The highest protein content of the final product, mycelial biomass, was about 45% on dry weight basis. More than 90% utilization of corn stover polysaccharides for the synthesis of protein-rich mycelial biomass of P. sajor-caju was recorded. (author)

Effect of irradiation, as a pretreatment, on bioconversion of corn stover into protein-rich mycelial biomass of Pleurotus sajor-caju

International Nuclear Information System (INIS)

Awafo, V.A.; Chahal, D.S.; Charbonneau, R.

1995-01-01

Application of irradiation for food preservation, for pretreatment of lignocellulosic materials for their hydrolysis and to increase the digestibility of lignocellulosic materials for rumen animals have been reported in the literature. In the present study, irradiation (100 KGy to 1.7 MGy) of corn stover as a pretreatment to make it susceptible for its bioconversion into protein-rich mycelial biomass of Pleurotus sajor-caju NRRL 18757 has been compared with that of mied alkali treatment (0.01 to 0.15 g NaOH/g corn stover), the most commonly used pretreatment. Protein synthesis increased with the increase in doses of irradiation as well as with the increase in concentration of NaOH. Combination pretreatment with NaOH and γ-irradiation reduced the quantity of NaOH and doses of irradiation required to get optimum yields of protein indicating a strong synergistic effect. This highest protein content of the final product, mycelial biomass, was about 45% on dry weight basis. More than 90% utilization of corn stover polysaccharides for the synthesis of protein-rich mycelial biomass of P.sajor-caju was recorded. (author)

Effect of irradiation, as a pretreatment, on bioconversion of corn stover into protein-rich mycelial biomass of Pleurotus sajor-caju

Energy Technology Data Exchange (ETDEWEB)

Awafo, V.A.; Chahal, D.S.; Charbonneau, R. [Universite du Quebec (Canada). Applied Microbiology Research Center

1995-10-01

Application of irradiation for food preservation, for pretreatment of lignocellulosic materials for their hydrolysis and to increase the digestibility of lignocellulosic materials for rumen animals have been reported in the literature. In the present study, irradiation (100 KGy to 1.7 MGy) of corn stover as a pretreatment to make it susceptible for its bioconversion into protein-rich mycelial biomass of Pleurotus sajor-caju NRRL 18757 has been compared with that of mild alkali treatment (0.01 to 0.15 g NaOH/g corn stover), the most commonly used pretreatment. Protein synthesis increased with the increase in doses of irradiation as well as with the increase in concentration of NaOH. Combination pretreatment with NaOH and {gamma}-irradiation reduced the quantity of NaOH and doses of irradiation required to get optimum yields of protein indicating a strong synergistic effect. The highest protein content of the final product, mycelial biomass, was about 45% on dry weight basis. More than 90% utilization of corn stover polysaccharides for the synthesis of protein-rich mycelial biomass of P. sajor-caju was recorded. (author).

Effect of γ-rays radiation pretreatment on enzymatic hydrolysis of corn straw for producing sugar

International Nuclear Information System (INIS)

Tang Hongtao; Ha Yiming; Wang Feng

2011-01-01

The effect of γ-rays radiation pretreatment on enzymatic of corn straw for producing sugar was studied. The relationship between irradiation-dosage and content of reducing sugar was investigated in DNS method. After 1000 kGy irradiation, the content of reducing sugar reached about 317.35%. A synergistic effect between irradiation and enzyme was observed. The reducing sugar yield after enzymatic hydrolysis reached 20.51% when the corn straw powder (0.15 mm) irradiated with a dose of 1000 kGy. The result shows that the irradiation had significant influence on enzymatic hydrolysis of corn straw. At the 500 kGy pre-irradiation, compared with initial yield, the maximum sugar yield of sample had increased by 13.68% while the irradiated corn straw stored in 20 days. (authors)

High-titer lactic acid production from NaOH-pretreated corn stover by Bacillus coagulans LA204 using fed-batch simultaneous saccharification and fermentation under non-sterile condition.

Science.gov (United States)

Hu, Jinlong; Zhang, Zhenting; Lin, Yanxu; Zhao, Shumiao; Mei, Yuxia; Liang, Yunxiang; Peng, Nan

2015-04-01

Lactic acid (LA) is an important chemical with various industrial applications. Non-food feedstock is commercially attractive for use in LA production; however, efficient LA fermentation from lignocellulosic biomass resulting in both high yield and titer faces technical obstacles. In this study, the thermophilic bacterium Bacillus coagulans LA204 demonstrated considerable ability to ferment glucose, xylose, and cellobiose to LA. Importantly, LA204 produces LA from several NaOH-pretreated agro stovers, with remarkably high yields through simultaneous saccharification and fermentation (SSF). A fed-batch SSF process conducted at 50°C and pH 6.0, using a cellulase concentration of 30 FPU (filter paper unit)/g stover and 10 g/L yeast extract in a 5-L bioreactor, was developed to produce LA from 14.4% (w/w) NaOH-pretreated non-sterile corn stover. LA titer, yield, and average productivity reached 97.59 g/L, 0.68 g/g stover, and 1.63 g/L/h, respectively. This study presents a feasible process for lignocellulosic LA production from abundant agro stovers. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pretreatment combining ultrasound and sodium percarbonate under mild conditions for efficient degradation of corn stover.

Science.gov (United States)

Nakashima, Kazunori; Ebi, Yuuki; Kubo, Masaki; Shibasaki-Kitakawa, Naomi; Yonemoto, Toshikuni

2016-03-01

Ultrasound (US) can be used to disrupt microcrystalline cellulose to give nanofibers via ultrasonic cavitation. Sodium percarbonate (SP), consisting of sodium carbonate and hydrogen peroxide, generates highly reactive radicals, which cause oxidative delignification. Here, we describe a novel pretreatment technique using a combination of US and SP (US-SP) for the efficient saccharification of cellulose and hemicellulose in lignocellulosic corn stover. Although US-SP pretreatment was conducted under mild condition (i.e., at room temperature and atmospheric pressure), the pretreatment greatly increased lignin removal and cellulose digestibility. We also determined the optimum US-SP treatment conditions, such as ultrasonic power output, pretreatment time, pretreatment temperature, and SP concentration for an efficient cellulose saccharification. Moreover, xylose could be effectively recovered from US-SP pretreated biomass without the formation of microbial inhibitor furfural. Copyright © 2015 Elsevier B.V. All rights reserved.

Enzymatic Xylose Release from Pretreated Corn Bran Arabinoxylan: Differential Effects of Deacetylation and Deferuloylation on Insoluble and Soluble Substrate Fractions

DEFF Research Database (Denmark)

Agger, Jane; Viksø-Nielsen, Ander; Meyer, Anne S.

2010-01-01

In the present work enzymatic hydrolysis of arabinoxylan from pretreated corn bran (190 °C, 10 min) was evaluated by measuring the release of xylose and arabinose after treatment with a designed minimal mixture of monocomponent enzymes consisting of α-l-arabinofuranosidases, an endoxylanase......, and a β-xylosidase. The pretreatment divided the corn bran material 50:50 into soluble and insoluble fractions having A:X ratios of 0.66 and 0.40, respectively. Addition of acetyl xylan esterase to the monocomponent enzyme mixture almost doubled the xylose release from the insoluble substrate fraction...

Characterization of lignin during oxidative and hydrothermal pre-treatment processes of wheat straw and corn stover.

Science.gov (United States)

Kaparaju, Prasad; Felby, Claus

2010-05-01

The objective of the study was to characterize and map changes in lignin during hydrothermal and wet explosion pre-treatments of wheat straw and corn stover. Chemical composition, microscopic (atomic force microscopy and scanning electron microscopy) and spectroscopic (attenuated total reflectance Fourier transform infrared spectroscopy, ATR-FTIR) analyses were performed. Results showed that both pre-treatments improved the cellulose and lignin content with substantial removal of hemicellulose in the pre-treated biomasses. These values were slightly higher for hydrothermal compared to wet explosion pre-treatment. ATR-FTIR analyses also confirmed these results. Microscopic analysis showed that pre-treatments affected the biomass by partial difibration. Lignin deposition on the surface of the hydrothermally pre-treated fibre was very distinct while severe loss of fibril integrity was noticed with wet exploded fibre. The present study thus revealed that the lignin cannot be removed by the studied pre-treatments. However, both pre-treatments improved the accessibility of the biomass towards enzymatic hydrolysis. Copyright 2009 Elsevier Ltd. All rights reserved.

A MICROWAVE-ASSISTED LIQUEFACTION AS A PRETREATMENT FOR THE BIOETHANOL PRODUCTION BY THE SIMULTANEOUS SACCHARIFICATION AND FERMENTATION OF CORN MEAL

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Svetlana Nikolić

2008-11-01

Full Text Available A microwave-assisted liquefaction as a pretreatment for the bioethanol production by the simultaneous saccharification and fer entation (SSF of corn meal using Saccharomyces cerevisiae var. ellipsoideus yeast in a batch system was studied. An optimal power of microwaves of 80 W and the 5-min duration of the microwave treatment were selected by following the concentration of glucose released from the corn meal suspensions at hidromodul of 1:3 (corn meal to water ratio in the liquefaction step. The results indicated that the microwave pretreatment could increase the maximum ethanol concentration produced in the SSF process for 13.4 %. Consequently, a significant increase of the ethanol productivity on substrate (YP/S, as well as the volumetric ethanol productivity (P in this process, could be achieved

A novel film-pore-surface diffusion model to explain the enhanced enzyme adsorption of corn stover pretreated by ultrafine grinding.

Science.gov (United States)

Zhang, Haiyan; Chen, Longjian; Lu, Minsheng; Li, Junbao; Han, Lujia

2016-01-01

Ultrafine grinding is an environmentally friendly pretreatment that can alter the degree of polymerization, the porosity and the specific surface area of lignocellulosic biomass and can, thus, enhance cellulose hydrolysis. Enzyme adsorption onto the substrate is a prerequisite for the enzymatic hydrolysis process. Therefore, it is necessary to investigate the enzyme adsorption properties of corn stover pretreated by ultrafine grinding. The ultrafine grinding pretreatment was executed on corn stover. The results showed that ultrafine grinding pretreatment can significantly decrease particle size [from 218.50 μm of sieve-based grinding corn stover (SGCS) to 17.45 μm of ultrafine grinding corn stover (UGCS)] and increase the specific surface area (SSA), pore volume (PV) and surface composition (SSA: from 1.71 m(2)/g of SGCS to 2.63 m(2)/g of UGCS, PV: from 0.009 cm(3)/g of SGCS to 0.024 m(3)/g of UGCS, cellulose surface area: from 168.69 m(2)/g of SGCS to 290.76 m(2)/g of UGCS, lignin surface area: from 91.46 m(2)/g of SGCS to 106.70 m(2)/g of UGCS). The structure and surface composition changes induced by ultrafine grinding increase the enzyme adsorption capacity from 2.83 mg/g substrate of SGCS to 5.61 mg/g substrate of UGCS. A film-pore-surface diffusion model was developed to simultaneously predict the enzyme adsorption kinetics of both the SGCS and UGCS. Satisfactory predictions could be made with the model based on high R (2) and low RMSE values (R (2) = 0.95 and RMSE = 0.16 mg/g for the UGCS, R (2) = 0.93 and RMSE = 0.09 mg/g for the SGCS). The model was further employed to analyze the rate-limiting steps in the enzyme adsorption process. Although both the external-film and internal-pore mass transfer are important for enzyme adsorption on the SGCS and UGCS, the UGCS has a lower internal-pore resistance compared to the SGCS. Ultrafine grinding pretreatment can enhance the enzyme adsorption onto corn stover by altering structure and

Deposition of lignin droplets produced during dilute acid pretreatment of maize stems retards enzymatic hydrolysis of cellulose.

Science.gov (United States)

Selig, Michael J; Viamajala, Sridhar; Decker, Stephen R; Tucker, Melvin P; Himmel, Michael E; Vinzant, Todd B

2007-01-01

Electron microscopy of lignocellulosic biomass following high-temperature pretreatment revealed the presence of spherical formations on the surface of the residual biomass. The hypothesis that these droplet formations are composed of lignins and possible lignin carbohydrate complexes is being explored. Experiments were conducted to better understand the formation of these "lignin" droplets and the possible implications they might have on the enzymatic saccharification of pretreated biomass. It was demonstrated that these droplets are produced from corn stover during pretreatment under neutral and acidic pH at and above 130 degrees C, and that they can deposit back onto the surface of residual biomass. The deposition of droplets produced under certain pretreatment conditions (acidic pH; T > 150 degrees C) and captured onto pure cellulose was shown to have a negative effect (5-20%) on the enzymatic saccharification of this substrate. It was noted that droplet density (per unit area) was greater and droplet size more variable under conditions where the greatest impact on enzymatic cellulose conversion was observed. These results indicate that this phenomenon has the potential to adversely affect the efficiency of enzymatic conversion in a lignocellulosic biorefinery.

Lactic Acid Production from Pretreated Hydrolysates of Corn Stover by a Newly Developed Bacillus coagulans Strain

Science.gov (United States)

Jiang, Ting; Qiao, Hui; Zheng, Zhaojuan; Chu, Qiulu; Li, Xin; Yong, Qiang; Ouyang, Jia

2016-01-01

An inhibitor-tolerance strain, Bacillus coagulans GKN316, was developed through atmospheric and room temperature plasma (ARTP) mutation and evolution experiment in condensed dilute-acid hydrolysate (CDH) of corn stover. The fermentabilities of other hydrolysates with B. coagulans GKN316 and the parental strain B. coagulans NL01 were assessed. When using condensed acid-catalyzed steam-exploded hydrolysate (CASEH), condensed acid-catalyzed liquid hot water hydrolysate (CALH) and condensed acid-catalyzed sulfite hydrolysate (CASH) as substrates, the concentration of lactic acid reached 45.39, 16.83, and 18.71 g/L by B. coagulans GKN316, respectively. But for B. coagulans NL01, only CASEH could be directly fermented to produce 15.47 g/L lactic acid. The individual inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF), vanillin, syringaldehyde and p-hydroxybenzaldehyde (pHBal) on xylose utilization by B. coagulans GKN316 was also studied. The strain B. coagulans GKN316 could effectively convert these toxic inhibitors to the less toxic corresponding alcohols in situ. These results suggested that B. coagulans GKN316 was well suited to production of lactic acid from undetoxified lignocellulosic hydrolysates. PMID:26863012

Lactic Acid Production from Pretreated Hydrolysates of Corn Stover by a Newly Developed Bacillus coagulans Strain.

Science.gov (United States)

Jiang, Ting; Qiao, Hui; Zheng, Zhaojuan; Chu, Qiulu; Li, Xin; Yong, Qiang; Ouyang, Jia

2016-01-01

An inhibitor-tolerance strain, Bacillus coagulans GKN316, was developed through atmospheric and room temperature plasma (ARTP) mutation and evolution experiment in condensed dilute-acid hydrolysate (CDH) of corn stover. The fermentabilities of other hydrolysates with B. coagulans GKN316 and the parental strain B. coagulans NL01 were assessed. When using condensed acid-catalyzed steam-exploded hydrolysate (CASEH), condensed acid-catalyzed liquid hot water hydrolysate (CALH) and condensed acid-catalyzed sulfite hydrolysate (CASH) as substrates, the concentration of lactic acid reached 45.39, 16.83, and 18.71 g/L by B. coagulans GKN316, respectively. But for B. coagulans NL01, only CASEH could be directly fermented to produce 15.47 g/L lactic acid. The individual inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF), vanillin, syringaldehyde and p-hydroxybenzaldehyde (pHBal) on xylose utilization by B. coagulans GKN316 was also studied. The strain B. coagulans GKN316 could effectively convert these toxic inhibitors to the less toxic corresponding alcohols in situ. These results suggested that B. coagulans GKN316 was well suited to production of lactic acid from undetoxified lignocellulosic hydrolysates.

Lactic Acid Production from Pretreated Hydrolysates of Corn Stover by a Newly Developed Bacillus coagulans Strain.

Directory of Open Access Journals (Sweden)

Ting Jiang

Full Text Available An inhibitor-tolerance strain, Bacillus coagulans GKN316, was developed through atmospheric and room temperature plasma (ARTP mutation and evolution experiment in condensed dilute-acid hydrolysate (CDH of corn stover. The fermentabilities of other hydrolysates with B. coagulans GKN316 and the parental strain B. coagulans NL01 were assessed. When using condensed acid-catalyzed steam-exploded hydrolysate (CASEH, condensed acid-catalyzed liquid hot water hydrolysate (CALH and condensed acid-catalyzed sulfite hydrolysate (CASH as substrates, the concentration of lactic acid reached 45.39, 16.83, and 18.71 g/L by B. coagulans GKN316, respectively. But for B. coagulans NL01, only CASEH could be directly fermented to produce 15.47 g/L lactic acid. The individual inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF, vanillin, syringaldehyde and p-hydroxybenzaldehyde (pHBal on xylose utilization by B. coagulans GKN316 was also studied. The strain B. coagulans GKN316 could effectively convert these toxic inhibitors to the less toxic corresponding alcohols in situ. These results suggested that B. coagulans GKN316 was well suited to production of lactic acid from undetoxified lignocellulosic hydrolysates.

Construction of a Bacterial Cellulase Cocktail for Saccharification of Regenerated Cellulose and Pretreated Corn Stover

Directory of Open Access Journals (Sweden)

Alei Geng

2015-09-01

Full Text Available To apply bacterial cellulases for efficient saccharification of biomass, three Clostridium thermocellum cellulases and a Thermoanaerobacter brockii β-1,4-glucosidase were synthesized in Escherichia coli, and the proportions among them were optimized. When the activities of CelD, CBHA, CBH48Y, and CglT were set at 554, 0.91, 0.91, and 856 mU per assay, respectively, the percent conversion of regenerated cellulose (0.92 g/L reached 80.9% within 24 h at 60 °C without shaking. Meanwhile, the percent conversion of pretreated corn stover (0.62 g/L reached 70.1%. Gradually raising the loads of regenerated cellulose from 0.92 to 4.58 g/L resulted in a linear increase in glucose production from 870 to 3208 μg (R2=0.997, as well as a decrease in the percent conversion from 80.9% to 59.6%. These findings suggested that the cellulase cocktail is efficient in saccharification of regenerated cellulose, as well as pretreated corn stover, and has potential applications in the biofuels industry.

Effect of hydrolysis enzymatic process of corn using protease crude (Rhizopus oligosporus-C1) to produce corn hydrolisate rich folic acid

Science.gov (United States)

Maryati, Yati; Susilowati, Agustine; Melanie, Hakiki; Lotulung, Puspa D.

2017-11-01

Corn hydrolyzate (Zea mays L) as a functional food fortificant derived from natural folic acid has been evaluated through a hydrolysis process using protease enzyme Rhizopus oligosporus strain C1. Enzymatic hydrolysis was carried out on two types of corn; yellow and white pearl variety corn, at concentration of protease enzyme (rough) 0.025; 0.125; and 0.225% (v/w of soluble nixtamal corn protein) with a hydrolysis time of 24 h at 30 °C, and pH 5.0. The results showed that the concentration of protease enzymes can increase the folic acid to the optimum condition, from the beginning to the end of the process time. Folic acid optimization of hydrolysis results in each corn was at the concentration of protease enzyme 0.225% (v/w of soluble nixtamal corn protein) in white corn and yellow corn at 24 hours hydrolysis, with folic acid composition, 283.56 µg/mL and 412.52 µg/mL, 1.07 and 1.04 mg/mL of soluble proteins, proteolytic activity 2.09 and 2.06 U/mL, total solids of 21.74 and 17.85%, total sugars of 0.56 and 2.22 mg/mL, and reducing sugar 91.72 and 48.47 mg/mL. In this condition, the increase of optimum folic acid for white corn was 33.57% and for yellow corn was 71.60% after hydrolysis.

Characteristics of Corn Stover Pretreated with Liquid Hot Water and Fed-Batch Semi-Simultaneous Saccharification and Fermentation for Bioethanol Production

Science.gov (United States)

Li, Xuezhi; Lu, Jie; Zhao, Jian; Qu, Yinbo

2014-01-01

Corn stover is a promising feedstock for bioethanol production because of its abundant availability in China. To obtain higher ethanol concentration and higher ethanol yield, liquid hot water (LHW) pretreatment and fed-batch semi-simultaneous saccharification and fermentation (S-SSF) were used to enhance the enzymatic digestibility of corn stover and improve bioconversion of cellulose to ethanol. The results show that solid residues from LHW pretreatment of corn stover can be effectively converted into ethanol at severity factors ranging from 3.95 to 4.54, and the highest amount of xylan removed was approximately 89%. The ethanol concentrations of 38.4 g/L and 39.4 g/L as well as ethanol yields of 78.6% and 79.7% at severity factors of 3.95 and 4.54, respectively, were obtained by fed-batch S-SSF in an optimum conditions (initial substrate consistency of 10%, and 6.1% solid residues added into system at the prehydrolysis time of 6 h). The changes in surface morphological structure, specific surface area, pore volume and diameter of corn stover subjected to LHW process were also analyzed for interpreting the possible improvement mechanism. PMID:24763192

Understanding the Impacts of AFEX™ Pretreatment and Densification on the Fast Pyrolysis of Corn Stover, Prairie Cord Grass, and Switchgrass.

Science.gov (United States)

Sundaram, Vijay; Muthukumarappan, Kasiviswanathan; Gent, Stephen

2017-03-01

Lignocellulosic feedstocks corn stover, prairie cord grass, and switchgrass were subjected to ammonia fiber expansion (AFEX™) pretreatment and densified using extrusion pelleting and ComPAKco densification technique. The effects of AFEX™ pretreatment and densification were studied on the fast pyrolysis product yields. Feedstocks were milled in a hammer mill using three different screen sizes (2, 4, and 8 mm) and were subjected to AFEX™ pretreatment. The untreated and AFEX™-pretreated feedstocks were moisture adjusted at three levels (5, 10, and 15 % wb) and were extruded using a lab-scale single screw extruder. The barrel temperature of the extruder was maintained at 75, 100, and 125 °C. Durability of the extruded pellets made from AFEX™-pretreated corn stover, prairie cord grass, and switchgrass varied from 94.5 to 99.2, 94.3 to 98.7, and 90.1 to 97.5 %, respectively. Results of the thermogravimetric analysis showed the decrease in the decomposition temperature of the all the feedstocks after AFEX™ pretreatment indicating the increase in thermal stability. Loose and densified feedstocks were subjected to fast pyrolysis in a lab-scale reactor, and the yields (bio-oil and bio-char) were measured. Bio-char obtained from the AFEX™-pretreated feedstocks exhibited increased bulk and particle density compared to the untreated feedstocks. The properties of the bio-oil were statistically similar for the untreated, AFEX™-pretreated, and AFEX™-pretreated densified feedstocks. Based on the bio-char and bio-oil yields, the AFEX™-pretreated feedstocks and the densified AFEX™-pretreated feedstocks (pellets and PAKs) exhibited similar behavior. Hence, it can be concluded that densifying the AFEX™-pretreated feedstocks could be a viable option in the biomass-processing depots to reduce the transportation costs and the logistical impediments without affecting the product yields.

Properties comparison of biochars from corn straw with different pretreatment and sorption behaviour of atrazine.

Science.gov (United States)

Zhao, Xuchen; Ouyang, Wei; Hao, Fanghua; Lin, Chunye; Wang, Fangli; Han, Sheng; Geng, Xiaojun

2013-11-01

Biochar has been recognised as an efficient pollution control material. In this study, biochars (CS450 and ADPCS450) were produced using corn straw with different pretreatment techniques (without and with ammonium dihydrogen phosphate (ADP)). The character of the two biochars was compared using elemental analysis, specific surface area (SSA) and Fourier transform infrared spectra (FTIR). ADPCS450 had a higher residue yield and a much larger specific surface area than CS450. The Freundlich, Langmuir and Redlich-Peterson models were used to interpret the sorption behaviour of atrazine (2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine), and the results fit the Redlich-Peterson equation best. The isothermal sorption parameters indicated that the sorption capacity of atrazine on ADPCS450 was much larger than the sorption capacity of atrazine on CS450. Atrazine sorption was also favoured in acidic solution and under higher temperature conditions. Copyright © 2013 Elsevier Ltd. All rights reserved.

GREET Pretreatment Module

Energy Technology Data Exchange (ETDEWEB)

Adom, Felix K. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Dunn, Jennifer B. [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division; Han, Jeongwoo [Argonne National Lab. (ANL), Argonne, IL (United States). Energy Systems Division

2014-09-01

A wide range of biofuels and biochemicals can be produced from cellulosic biomass via different pretreatment technologies that yield sugars. Process simulations of dilute acid and ammonia fiber expansion pretreatment processes and subsequent hydrolysis were developed in Aspen Plus for four lignocellulosic feedstocks (corn stover, miscanthus, switchgrass, and poplar). This processing yields sugars that can be subsequently converted to biofuels or biochemical. Material and energy consumption data from Aspen Plus were then compiled in a new Greenhouses Gases, Regulated Emissions, and Energy Use in Transportation (GREET^TM) pretreatment module. The module estimates the cradle-to-gate fossil energy consumption (FEC) and greenhouse gas (GHG) emissions associated with producing fermentable sugars. This report documents the data and methodology used to develop this module and the cradle-to-gate FEC and GHG emissions that result from producing fermentable sugars.

Production of ethanol and furfural from corn stover

Science.gov (United States)

Corn stover has potential for economical production of biofuels and value-added chemicals. The conversion of corn stover to sugars involves pretreatment and enzymatic hydrolysis. We have optimized hydrothermal, dilute H2SO4 and dilute H3PO4 pretreatments of corn stover for enzymatic saccharificati...

Ethanol production from hydrothermal pretreated corn stover with a loop reactor

DEFF Research Database (Denmark)

Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

2010-01-01

to the different pretreatment times. The glucan recovered from liquid was from 4.9% to 5.6% and the total glucan recoveries from all the pretreatments were higher than 98%. Besides HMF and furfural, acetic, lactic, formic and glycolic acids were also found in the liquid phase. All the concentrations...

Biomass pretreatment affects Ustilago maydis in producing itaconic acid

Directory of Open Access Journals (Sweden)

Klement Tobias

2012-04-01

Full Text Available Abstract Background In the last years, the biotechnological production of platform chemicals for fuel components has become a major focus of interest. Although ligno-cellulosic material is considered as suitable feedstock, the almost inevitable pretreatment of this recalcitrant material may interfere with the subsequent fermentation steps. In this study, the fungus Ustilago maydis was used to produce itaconic acid as platform chemical for the synthesis of potential biofuels such as 3-methyltetrahydrofuran. No studies, however, have investigated how pretreatment of ligno-cellulosic biomass precisely influences the subsequent fermentation by U. maydis. Thus, this current study aims to first characterize U. maydis in shake flasks and then to evaluate the influence of three exemplary pretreatment methods on the cultivation and itaconic acid production of this fungus. Cellulose enzymatically hydrolysed in seawater and salt-assisted organic-acid catalysed cellulose were investigated as substrates. Lastly, hydrolysed hemicellulose from fractionated beech wood was applied as substrate. Results U. maydis was characterized on shake flask level regarding its itaconic acid production on glucose. Nitrogen limitation was shown to be a crucial condition for the production of itaconic acid. For itaconic acid concentrations above 25 g/L, a significant product inhibition was observed. Performing experiments that simulated influences of possible pretreatment methods, U. maydis was only slightly affected by high osmolarities up to 3.5 osmol/L as well as of 0.1 M oxalic acid. The production of itaconic acid was achieved on pretreated cellulose in seawater and on the hydrolysed hemicellulosic fraction of pretreated beech wood. Conclusion The fungus U. maydis is a promising producer of itaconic acid, since it grows as single cells (yeast-like in submerged cultivations and it is extremely robust in high osmotic media and real seawater. Moreover, U. maydis can grow on

Steam explosion enhances digestibility and fermentation of corn stover by facilitating ruminal microbial colonization.

Science.gov (United States)

Zhao, Shengguo; Li, Guodong; Zheng, Nan; Wang, Jiaqi; Yu, Zhongtang

2018-04-01

The purpose of this study was to evaluate steam explosion as a pretreatment to enhance degradation of corn stover by ruminal microbiome. The steam explosion conditions were first optimized, and then the efficacy of steam explosion was evaluated both in vitro and in vivo. Steam explosion altered the physical and chemical structure of corn stover as revealed by scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy, respectively, and increased its cellulose content while decreasing hemicellulose content. Steam-exploded corn stover also increased release of reducing sugars, rate of fermentation, and production of volatile fatty acids (VFAs) in vitro. The steam explosion treatment increased microbial colonization and in situ degradation of cellulose and hemicellulose of corn stover in the rumen of dairy cows. Steam explosion may be a useful pretreatment of corn stover to improve its nutritional value as forage for cattle, or as feedstock for biofuel production. Copyright © 2018 Elsevier Ltd. All rights reserved.

Impact of co-pretreatment of calcium hydroxide and steam explosion on anaerobic digestion efficiency with corn stover.

Science.gov (United States)

Ji, Jinli; Zhang, Jiyu; Yang, Liutianyi; He, Yanfeng; Zhang, Ruihong; Liu, Guangqing; Chen, Chang

2017-06-01

Anaerobic digestion (AD) is an effective way to utilize the abundant resource of corn stover (CS). In this light, Ca(OH) 2 pretreatment alone, steam explosion (SE) pretreatment alone, and co-pretreatment of Ca(OH) 2 and SE were applied to improve the digestion efficiency of CS. Results showed that AD of co-pretreated CS with 1.0% Ca(OH) 2 and SE at 1.5 MPa achieved the highest cumulative methane yield of [Formula: see text], which was 61.54% significantly higher (p < .01) than untreated CS. The biodegradability value of CS after co-pretreatment enhanced from 43.03% to 69.52%. Methane yield could be well fitted by the first-order model and the modified Gompertz model. In addition, composition and structural changes of CS after pretreatment were analyzed by a fiber analyzer, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray diffraction. The validated results indicated that co-pretreatment of Ca(OH) 2 and SE was efficient to improve the digestion performance of CS and might be a suitable method for agricultural waste pretreatment in the future AD industry.

Parametric study for the optimization of ionic liquid pretreatment of corn stover

Energy Technology Data Exchange (ETDEWEB)

Papa, Gabriella [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Feldman, Taya [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Sale, Kenneth L. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Adani, Fabrizio [Univ. degli Studi di Milano (Italy); Singh, Seema [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Sandia National Lab. (SNL-CA), Livermore, CA (United States); Simmons, Blake A. [Joint BioEnergy Inst. (JBEI), Emeryville, CA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

2017-05-30

A parametric study of the efficacy of the ionic liquid (IL) pretreatment (PT) of corn stover (CS) using 1-ethyl-3-methylimidazolium acetate ([C₂C₁Im][OAc] ) and cholinium lysinate ([Ch][Lys] ) was conducted. The impact of 50% and 15% biomass loading for milled and non-milled CS on IL-PT was evaluated, as well the impact of 20 and 5 mg enzyme/g glucan on saccharification efficiency. The glucose and xylose released were generated from 32 conditions – 2 ionic liquids (ILs), 2 temperatures, 2 particle sizes (S), 2 solid loadings, and 2 enzyme loadings. Statistical analysis indicates that sugar yields were correlated with lignin and xylan removal and depends on the factors, where S did not explain variation in sugar yields. Both ILs were effective in pretreating large particle sized CS, without compromising sugar yields. The knowledge from material and energy balances is an essential step in directing optimization of sugar recovery at desirable process conditions.

Parametric study for the optimization of ionic liquid pretreatment of corn stover.

Science.gov (United States)

Papa, Gabriella; Feldman, Taya; Sale, Kenneth L; Adani, Fabrizio; Singh, Seema; Simmons, Blake A

2017-10-01

A parametric study of the efficacy of the ionic liquid (IL) pretreatment (PT) of corn stover (CS) using 1-ethyl-3-methylimidazolium acetate ([C 2 C 1 Im][OAc]) and cholinium lysinate ([Ch][Lys]) was conducted. The impact of 50% and 15% biomass loading for milled and non-milled CS on IL-PT was evaluated, as well the impact of 20 and 5mg enzyme/g glucan on saccharification efficiency. The glucose and xylose released were generated from 32 conditions - 2 ionic liquids (ILs), 2 temperatures, 2 particle sizes (S), 2 solid loadings, and 2 enzyme loadings. Statistical analysis indicates that sugar yields were correlated with lignin and xylan removal and depends on the factors, where S did not explain variation in sugar yields. Both ILs were effective in pretreating large particle sized CS, without compromising sugar yields. The knowledge from material and energy balances is an essential step in directing optimization of sugar recovery at desirable process conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tissue-specific biomass recalcitrance in corn stover pretreated with liquid hot-water: enzymatic hydrolysis (part 1).

Science.gov (United States)

Zeng, Meijuan; Ximenes, Eduardo; Ladisch, Michael R; Mosier, Nathan S; Vermerris, Wilfred; Huang, Chia-Ping; Sherman, Debra M

2012-02-01

Lignin content, composition, distribution as well as cell wall thickness, structures, and type of tissue have a measurable effect on enzymatic hydrolysis of cellulose in lignocellulosic feedstocks. The first part of our work combined compositional analysis, pretreatment and enzyme hydrolysis for fractionated pith, rind, and leaf tissues from a hybrid stay-green corn, in order to identify the role of structural characteristics on enzyme hydrolysis of cell walls. The extent of enzyme hydrolysis follows the sequence rind cellulose to glucose in 24 h in the best cases. Physical fractionation of corn stalks or other C(4) grasses into soft and hard tissue types could reduce cost of cellulose conversion by enabling reduced enzyme loadings to hydrolyze soft tissue, and directing the hard tissue to other uses such as thermal processing, combustion, or recycle to the land from which the corn was harvested. Copyright © 2011 Wiley Periodicals, Inc.

Effect of pelleting process variables on physical properties and sugar yields of ammonia fiber expansion pretreated corn stover

Energy Technology Data Exchange (ETDEWEB)

Amber N. Hoover; Jaya Shankar Tumuluru; Farzaneh Teymouri; Garold L. Gresham; Janette Moore

2014-07-01

Pelletization process variables including grind size (4, 6 mm), die speed (40, 50, 60 Hz), and preheating (none, 70 degrees C) were evaluated to understand their effect on pellet quality attributes and sugar yields of ammonia fiber expansion (AFEX) pretreated biomass. The bulk density of the pelletized AFEX corn stover was three to six times greater compared to untreated and AFEX-treated corn stover. Also the durability of the pelletized AFEX corn stover was >97.5% for all pelletization conditions studied except for preheated pellets. Die speed had no effect on enzymatic hydrolysis sugar yields of pellets. Pellets produced with preheating or a larger grind size (6 mm) had similar or lower sugar yields. Pellets generated with 4 mm AFEX-treated corn stover, a 60 Hz die speed, and no preheating resulted in pellets with similar or greater density, durability, and sugar yields compared to other pelletization conditions.

Comparison of Different Biomass Pretreatment Techniques and Their Impact on Chemistry and Structure

International Nuclear Information System (INIS)

Singh, Seema; Cheng, Gang; Sathitsuksanoh, Noppadon; Wu, Dong; Varanasi, Patanjali; George, Anthe; Balan, Venkatesh; Gao, Xiadi; Kumar, Rajeev; Dale, Bruce E.; Wyman, Charles E.; Simmons, Blake A.

2015-01-01

Pretreatment of lignocellulosic biomass is a prerequisite to overcome recalcitrance and allow enzyme accessibility to cellulose and maximize product recovery for improved economics of second-generation lignocellulosic bio-refineries. Recently, the three US-DOE funded Bioenergy Research Centers [Joint Bioenergy Institute (JBEI), Great Lakes Bioenergy Research Center (GLBRC), and BioEnergy Science Center (BESC)] compared ionic liquid (IL), dilute sulfuric acid (DA), and ammonia fiber expansion (AFEX TM ) pretreatments and published comparative data on mass balance, total sugar yields, substrate accessibility, and microbial fermentation [Biotechnology for Biofuels 7: 71; 72 (2014)]. In this study, corn stover solids from IL, DA, and AFEX pretreatments were compared to gain comprehensive, in-depth understanding of induced morphological and chemical changes incorporated to corn stover, and how they overcome the biomass recalcitrance. These studies reveal that biomass recalcitrance is overcome by combination of structural and chemical changes to carbohydrates and lignin after pretreatment. Thermal analysis indicates that AFEX and IL pretreated corn stover showed a lower thermal stability while DA pretreated corn stover showed the opposite. The surface roughness variations measured by small-angle neutron scattering were correlated to the removal and redistribution of biomass components and was consistent with compositional analysis, atomic force microscopy (AFM) and confocal fluorescence imaging results. With AFM and confocal fluorescent microscopy, lignin was found to be re-deposited on cellulose surface with average cellulose fiber width significantly decreased for DA pretreated corn stover (one-third of IL and AFEX). HSQC NMR spectra revealed a ~17.9% reduction of β-aryl ether units after AFEX, ~59.8% reduction after DA, and >98% reduction after IL. Both NMR and size exclusion chromatography showed similar patterns of lignin de-polymerization with highest degree of de

Comparison of Different Biomass Pretreatment Techniques and Their Impact on Chemistry and Structure

Energy Technology Data Exchange (ETDEWEB)

Singh, Seema, E-mail: seesing@sandia.gov; Cheng, Gang; Sathitsuksanoh, Noppadon; Wu, Dong; Varanasi, Patanjali; George, Anthe [Deconstruction Division, Joint BioEnergy Institute (JBEI), Emeryville, CA (United States); Sandia National Laboratories, Biological and Materials Sciences Center, Livermore, CA (United States); Balan, Venkatesh [Department of Chemical Engineering and Materials Science, DOE Great Lakes BioEnergy Research Center (GLBRC), Michigan State University, Lansing, MI (United States); Gao, Xiadi [Oak Ridge National Laboratory, BioEnergy Science Center (BESC), Oak Ridge, TN (United States); Department of Chemical and Environmental Engineering, Bourns College of Engineering, Riverside, CA (United States); Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California Riverside, Riverside, CA (United States); Kumar, Rajeev [Oak Ridge National Laboratory, BioEnergy Science Center (BESC), Oak Ridge, TN (United States); Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California Riverside, Riverside, CA (United States); Dale, Bruce E. [Department of Chemical Engineering and Materials Science, DOE Great Lakes BioEnergy Research Center (GLBRC), Michigan State University, Lansing, MI (United States); Wyman, Charles E. [Oak Ridge National Laboratory, BioEnergy Science Center (BESC), Oak Ridge, TN (United States); Department of Chemical and Environmental Engineering, Bourns College of Engineering, Riverside, CA (United States); Center for Environmental Research and Technology (CE-CERT), Bourns College of Engineering, University of California Riverside, Riverside, CA (United States); Simmons, Blake A. [Deconstruction Division, Joint BioEnergy Institute (JBEI), Emeryville, CA (United States); Sandia National Laboratories, Biological and Materials Sciences Center, Livermore, CA (United States)

2015-02-06

Pretreatment of lignocellulosic biomass is a prerequisite to overcome recalcitrance and allow enzyme accessibility to cellulose and maximize product recovery for improved economics of second-generation lignocellulosic bio-refineries. Recently, the three US-DOE funded Bioenergy Research Centers [Joint Bioenergy Institute (JBEI), Great Lakes Bioenergy Research Center (GLBRC), and BioEnergy Science Center (BESC)] compared ionic liquid (IL), dilute sulfuric acid (DA), and ammonia fiber expansion (AFEX{sup TM}) pretreatments and published comparative data on mass balance, total sugar yields, substrate accessibility, and microbial fermentation [Biotechnology for Biofuels 7: 71; 72 (2014)]. In this study, corn stover solids from IL, DA, and AFEX pretreatments were compared to gain comprehensive, in-depth understanding of induced morphological and chemical changes incorporated to corn stover, and how they overcome the biomass recalcitrance. These studies reveal that biomass recalcitrance is overcome by combination of structural and chemical changes to carbohydrates and lignin after pretreatment. Thermal analysis indicates that AFEX and IL pretreated corn stover showed a lower thermal stability while DA pretreated corn stover showed the opposite. The surface roughness variations measured by small-angle neutron scattering were correlated to the removal and redistribution of biomass components and was consistent with compositional analysis, atomic force microscopy (AFM) and confocal fluorescence imaging results. With AFM and confocal fluorescent microscopy, lignin was found to be re-deposited on cellulose surface with average cellulose fiber width significantly decreased for DA pretreated corn stover (one-third of IL and AFEX). HSQC NMR spectra revealed a ~17.9% reduction of β-aryl ether units after AFEX, ~59.8% reduction after DA, and >98% reduction after IL. Both NMR and size exclusion chromatography showed similar patterns of lignin de-polymerization with highest degree

Comparison of Different Biomass Pretreatment Techniques and their Impact on Chemistry and Structure

Directory of Open Access Journals (Sweden)

Seema eSingh

2015-02-01

Full Text Available Pretreatment of lignocellulosic biomass is a prerequisite to overcome recalcitrance and allow enzyme accessibility to cellulose and maximize product recovery for improved economics of second-generation lignocellulosic bio-refineries. Recently, the three US-DOE funded Bioenergy Research Centers (Joint Bioenergy Institute (JBEI, Great Lakes Bioenergy Research Center (GLBRC, and BioEnergy Science Center (BESC compared ionic liquid (IL, dilute sulfuric acid (DA, and ammonia fiber expansion (AFEXTM pretreatments and published comparative data on mass balance, total sugar yields, substrate accessibility, and microbial fermentation (Biotechnology for Biofuels 7: 71; 72 (2014. In this study, corn stover solids from IL, DA, and AFEX pretreatments were compared to gain comprehensive, in-depth understanding of induced morphological and chemical changes incorporated to corn stover, and how they overcome the biomass recalcitrance. These studies reveal that biomass recalcitrance is overcome by combination of structural and chemical changes to carbohydrates and lignin after pretreatment. Thermal analysis indicates that AFEX and IL pretreated corn stover showed a lower thermal stability while DA pretreated corn stover showed the opposite. The surface roughness variations measured by SANS were correlated to the removal and redistribution of biomass components and was consistent with compositional analysis, AFM and confocal fluorescence imaging results. With AFM and confocal fluorescent microscopy, lignin was found to be re-deposited on cellulose surface with average cellulose fiber width significantly decreased for DA pretreated corn stover (one third of IL and AFEX. HSQC NMR spectra revealed a ~17.9% reduction of β-aryl ether units after AFEX, ~59.8% reduction after DA and >98% reduction after IL. Both NMR and SEC showed similar patterns of lignin depolymerization with highest degree of depolymerization observed for IL followed with DA and AFEX.

[Enhancement of anaerobic digestion of excess sludge by acid-alkali pretreatment].

Science.gov (United States)

Yuan, Guang-Huan; Zhou, Xing-Qiu; Wu, Jian-Dong

2012-06-01

In order to enhance the efficiency of anaerobic digestion of excess sludge, acid-alkali pretreatment method was studied. Three different pretreatment methods (alkali alone,acid-alkali, alkali-acid) were compared to investigate their impacts on hydrolysis and acidification of activated sludge. In addition, their influences on methane-producing in subsequent anaerobic digestion process were also studied. The results showed that the soluble chemical oxygen demand (SCOD) of alkaline treatment alone was about 16% higher than the combining of acid and alkali treatment, SCOD concentration increased to 5406.1 mg x L(-1) after 8 d pretreatment. After treated by acid (pH 4.0, 4 d) and alkali (pH 10.0, 4 d), the acetic acid production and its content in short-chain fatty acids (SCFAs) were higher than other pretreatment methods. And the acetic acid production (as COD/VSS) could reach 74.4 mg x g(-1), accounting for 60.5% of SCFAs. After acid-alkali pretreatment, the C: N ratio of the sludge mixed liquor was about 25, and the C: P ratio was between 35-40, which was more favorable than C: N and C: P ratio of alkali alone and alkali-acid to subsequent anaerobic digestion. The control experiments showed that, after acid-alkali pretreatment, anaerobic digestion cumulative methane yield (CH4/VSS(in)) reached to 136.1 mL x g(-1) at 15 d, which was about 2.5-, 1.6-, and 1.7-fold of the blank (unpretreated), alkali alone pretreatment and alkali-acid pretreatment, respectively. After acid-alkali pretreatment for 8 d and anaerobic digestion for 15 d, the removal efficiency of VSS was about 60.9%, and the sludge reduction effect was better than other pretreatments. It is obvious that the acid-alkali pretreatment method was more favorable to anaerobic digestion and sludge reduction.

Pretreatment of Dried Distiller Grains with Solubles by Soaking in Aqueous Ammonia and Subsequent Enzymatic/Dilute Acid Hydrolysis to Produce Fermentable Sugars.

Science.gov (United States)

Nghiem, Nhuan P; Montanti, Justin; Kim, Tae Hyun

2016-05-01

Dried distillers grains with solubles (DDGS), a co-product of corn ethanol production in the dry-grind process, was pretreated by soaking in aqueous ammonia (SAA) using a 15 % w/w NH4OH solution at a solid/liquid ratio of 1:10. The effect of pretreatment on subsequent enzymatic hydrolysis was studied at two temperatures (40 and 60 °C) and four reaction times (6, 12, 24, and 48 h). Highest glucose yield of 91 % theoretical was obtained for the DDGS pretreated at 60 °C and 24 h. The solubilized hemicellulose in the liquid fraction was further hydrolyzed with dilute H2SO4 to generate fermentable monomeric sugars. The conditions of acid hydrolysis included 1 and 4 wt% acid, 60 and 120 °C, and 0.5 and 1 h. Highest yields of xylose and arabinose were obtained at 4 wt% acid, 120 °C, and 1 h. The fermentability of the hydrolysate obtained by enzymatic hydrolysis of the SAA-pretreated DDGS was demonstrated in ethanol fermentation by Saccharomyces cerevisiae. The fermentability of the hydrolysate obtained by consecutive enzymatic and dilute acid hydrolysis was demonstrated using a succinic acid-producing microorganism, strain Escherichia coli AFP184. Under the fermentation conditions, complete utilization of glucose and arabinose was observed, whereas only 47 % of xylose was used. The succinic acid yield was 0.60 g/g total sugar consumed.

Connecting lignin-degradation pathway with pretreatment inhibitor sensitivity of Cupriavidus necator

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Wei eWang

2014-05-01

Full Text Available To produce lignocellulosic biofuels economically, the complete release of monomers from the plant cell wall components, cellulose, hemicellulose and lignin, through pretreatment and hydrolysis (both enzymatic and chemical, and the efficient utilization of these monomers as carbon sources, is crucial. In addition, the identification and development of robust microbial biofuel production strains that can tolerate the toxic compounds generated during pretreatment and hydrolysis is also essential. In this work, Cupriavidus necator was selected due to its capabilities for utilizing lignin monomers and producing polyhydroxylbutyrate (PHB, a bioplastic as well as an advanced biofuel intermediate. We characterized the growth kinetics of C. necator in pretreated corn stover slurry as well as individually in the presence of 11 potentially toxic compounds in the saccharified slurry. We found that C. necator was sensitive to the saccharified slurry produced from dilute acid pretreated corn stover. Five out of 11 compounds within the slurry were characterized as toxic to C. necator, namely ammonium acetate, furfural, hydroxymethylfurfural (HMF, benzoic acid, and p-coumaric acid. Aldehydes (e.g., furfural and HMF were more toxic than the acetate and the lignin degradation products benzoic acid and p-coumaric acid; furfural was identified as the most toxic compound. Although toxic to C. necator at high concentration, ammonium acetate, benzoic acid, and p-coumaric acid could be utilized by C. necator with a stimulating effect on C. necator growth. Consequently, the lignin degradation pathway of C. necator was reconstructed based on genomic information and literature. The efficient conversion of intermediate catechol to downstream products of cis,cis-muconate or 2-hydroxymuconate-6-semialdehyde may help improve the robustness of C. necator to benzoic acid and p-coumaric acid as well as improve PHB productivity.

Oxidation of indole-3-acetic acid to oxindole-3-acetic acid by etiolated and green corn tissues

International Nuclear Information System (INIS)

Reinecke, D.

1989-01-01

Etiolated corn tissues oxidase indole-3-acetic acid (IAA) to oxindole-3-acetic acid (OxIAA). This oxidation results in loss of auxin activity and may plant a role in regulating IAA-stimulated growth. The enzyme has been partially purified and characterized and shown to require O 2 , and a heat-stable lipid-soluble corn factor which can be replaced by linolenic or linoleic acids in the oxidation of IAA. Corn oil was tested as a cofactor in the IAA oxidation reaction. Corn oil stimulated enzyme activity by 30% while trilinolein was inactive. The capacity of green tissue to oxidize IAA was examined by incubating leaf sections from 2 week old light-grown corn seedlings with 14 C-IAA. OxIAA and IAA were separated from other IAA metabolites on a 3 ml anion exchange column. Of the IAA taken up by the sections, 13% was oxidized to OxIAA. This is the first evidence that green tissue of corn may also regulate IAA levels by oxidizing IAA to OxIAA

Impact of Sequential Ammonia Fiber Expansion (AFEX) Pretreatment and Pelletization on the Moisture Sorption Properties of Corn Stover

Energy Technology Data Exchange (ETDEWEB)

Bonner, Ian J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Thompson, David N. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Teymouri, Farzaneh [Michigan Biotechnology Inst., Lansing, MI (United States); Campbell, Timothy [Michigan Biotechnology Inst., Lansing, MI (United States); Bals, Bryan [Michigan Biotechnology Inst., Lansing, MI (United States); Tumuluru, Jaya Shankar [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2015-05-01

Combining ammonia fiber expansion (AFEX™) pretreatment with a depot processing facility is a promising option for delivering high-value densified biomass to the emerging bioenergy industry. However, because the pretreatment process results in a high moisture material unsuitable for pelleting or storage (40% wet basis), the biomass must be immediately dried. If AFEX pretreatment results in a material that is difficult to dry, the economics of this already costly operation would be at risk. This work tests the nature of moisture sorption isotherms and thin-layer drying behavior of corn (Zea mays L.) stover at 20°C to 60°C before and after sequential AFEX pretreatment and pelletization to determine whether any negative impacts to material drying or storage may result from the AFEX process. The equilibrium moisture content to equilibrium relative humidity relationship for each of the materials was determined using dynamic vapor sorption isotherms and modeled with modified Chung-Pfost, modified Halsey, and modified Henderson temperature-dependent models as well as the Double Log Polynomial (DLP), Peleg, and Guggenheim Anderson de Boer (GAB) temperature-independent models. Drying kinetics were quantified under thin-layer laboratory testing and modeled using the Modified Page's equation. Water activity isotherms for non-pelleted biomass were best modeled with the Peleg temperature-independent equation while isotherms for the pelleted biomass were best modeled with the Double Log Polynomial equation. Thin-layer drying results were accurately modeled with the Modified Page's equation. The results of this work indicate that AFEX pretreatment results in drying properties more favorable than or equal to that of raw corn stover, and pellets of superior physical stability in storage.

Preparation and Characteristics of Corn Straw-Co-AMPS-Co-AA Superabsorbent Hydrogel

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Wei-Min Cheng

2015-11-01

Full Text Available In this study, the corn straw after removing the lignin was grafted with 2-acrylamido-2-methylpropanesulfonic acid (AMPS to prepare sulfonated cellulose. The grafting copolymerization between the sulfonated cellulose and acrylic acid (AA was performed using potassium persulfate and N,N′-methylenebisacrylamide as the initiator and crosslinking agent, respectively, to prepare corn straw-co-AMPS-co-AA hydrogels. The structure and properties of the resulting hydrogels were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and dynamic rheometry. The effects of initiator, crosslinker, monomer neutralization degree, and temperature on the swelling ratio of the hydrogels were studied. The water retention, salt resistance, and recyclability of the corn straw-co-AMPS-co-AA hydrogels were also investigated. The optimum water absorptivity of the corn straw hydrogels was obtained at a polymerization temperature of 50 °C with 1.2% crosslinker, 1:7 ratio of the pretreated corn straw and AA, 2% initiator, and 50% neutralized AA.

The Role of Product Inhibition as a Yield-Determining Factor in Enzymatic High-Solid Hydrolysis of Pretreated Corn Stover

DEFF Research Database (Denmark)

Nymand Olsen, Søren; Borch, Kim; Cruys-Bagger, Nicolaj

2014-01-01

. The results suggest that the solid effect is mainly controlled by product inhibition under the given experimental conditions (washed pretreated corn stover as substrate). Cellobiose was found to be approximately 15 times more inhibitory than glucose on a molar scale. However, considering that glucose...

Incorporation of 15N-inorganic nitrogen into free-amino acids in germinating corn

International Nuclear Information System (INIS)

Samukawa, Kisaburo; Yamaguchi, Masuro

1979-01-01

Incorporation of 15 N-labeled compounds, (K 15 NO 3 ) and ( 15 NH 4 ) 2 SO 4 , into free-amino acids was measured in germinating corn. Sterilized seeds of sweet corn (Choko No. 865) were sown on the filter papers soaked in 10 ml of the solution containing one of the labeled compounds (40 ppm N, 99 atom % excess) in petri dishes and germinated at 30 deg C. After 48 hours and 72 hours, 15 N-incorporation was measured in 5 seedlings selected owing to uniform growth. A GC-MS was used for measuring the ratio of 15 N isotopes present in free-amino acids. 15 N incorporation into free-amino acids hardly occurred when corn was germinated in the solution containing K 15 NO 3 , which suggested that endogenous nitrogen was used during the early germination stage of corn when nitrate is present. Incorporation into amino acids was greater when corn was germinated in the medium containing ( 15 NH 4 ) 2 SO 4 , than the case of the solution containing K 15 NO 3 . When corn was germinated in the solution containing ( 15 NH 4 ) 2 SO 4 , assimilation of 15 N into asparagine or aspartic acid was comparatively higher than that into the other amino acids, though the incorporation rate was low. Thus, in intact germinating corn, the hydrolyzed product of protein was utilized for germination with priority, and dependence on exogenous nitrogen was low. (Kaihara, S.)

Improved pretreatment of lignocellulosic biomass using enzymatically-generated peracetic acid.

Science.gov (United States)

Yin, DeLu Tyler; Jing, Qing; AlDajani, Waleed Wafa; Duncan, Shona; Tschirner, Ulrike; Schilling, Jonathan; Kazlauskas, Romas J

2011-04-01

Release of sugars from lignocellulosic biomass is inefficient because lignin, an aromatic polymer, blocks access of enzymes to the sugar polymers. Pretreatments remove lignin and disrupt its structure, thereby enhancing sugar release. In previous work, enzymatically generated peracetic acid was used to pretreat aspen wood. This pretreatment removed 45% of the lignin and the subsequent saccharification released 97% of the sugars remaining after pretreatment. In this paper, the amount of enzyme needed is reduced tenfold using first, an improved enzyme variant that makes twice as much peracetic acid and second, a two-phase reaction to generate the peracetic acid, which allows enzyme reuse. In addition, the eight pretreatment cycles are reduced to only one by increasing the volume of peracetic acid solution and increasing the temperature to 60 °C and the reaction time to 6h. For the pretreatment step, the weight ratio of peracetic acid to wood determines the amount of lignin removed. Copyright © 2011 Elsevier Ltd. All rights reserved.

Leaf application of silicic acid to upland rice and corn

Directory of Open Access Journals (Sweden)

Carlos Alexandre Costa Crusciol

2013-12-01

Full Text Available This study aimed to evaluate the effect of Si (stabilized silicic acid, Silamol® leaf application on mineral nutrition and yield in upland rice and corn crops. The treatments were the control (without Si and Si foliar split spraying using 2 L ha-1 of the Silamol® commercial product, with 0.8% soluble Si as concentrated stabilized silicic acid. Silicon leaf application increased the concentrations of K, Ca and Si in rice and corn leaves, the number of panicles per m2 of rice and the number of grains per ear of corn; accordingly, the Si leaf application provided a higher grain yield in both crops.

A new magnesium bisulfite pretreatment (MBSP) development for bio-ethanol production from corn stover.

Science.gov (United States)

Yu, Heng; Ren, Jiwei; Liu, Lei; Zheng, Zhaojuan; Zhu, Junjun; Yong, Qiang; Ouyang, Jia

2016-01-01

This study established a new more neutral magnesium bisulfate pretreatment (MBSP) using magnesium bisulfate as sulfonating agent for improving the enzymatic hydrolysis efficiency of corn stover. Using the MBSP with 5.21% magnesium bisulfate, 170°C and pH 5.2 for 60 min, about 90% of lignin and 80% of hemicellulose were removed from biomass and more than 90% cellulose conversion of substrate was achieved after 48 h hydrolysis. About 6.19 kg raw corn stover could produce 1 kg ethanol by Saccharomyces cerevisiae. Meanwhile, MBSP also could protect sugars from excessive degradation, prevent fermentation inhibition formation and directly convert the hemicelluloses into xylooligosaccharides as higher-value products. These results suggested that the MBSP method offers an alternative approach to the efficient conversion of nonwoody lignocellulosic biomass to ethanol and had broad space for development. Copyright © 2015 Elsevier Ltd. All rights reserved.

Efficient transformation of corn stover to furfural using p-hydroxybenzenesulfonic acid-formaldehyde resin solid acid.

Science.gov (United States)

Zhang, Tingwei; Li, Wenzhi; An, Shengxin; Huang, Feng; Li, Xinzhe; Liu, Jingrong; Pei, Gang; Liu, Qiying

2018-05-24

In this work, p-hydroxybenzenesulfonic acid-formaldehyde resin acid catalyst (MSPFR), was synthesized by a hydrothermal method, and employed for the furfural production from raw corn stover. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), N 2 adsorption-desorption, elemental analysis (EA), thermogravimetric analysis (TGA), and Fourier transform infrared spectroscopy (FT-IR) were used to characterize the MSPFR. The effects of reaction time, temperature, solvents and corn stover loading were investigated. The MSPFR presented high catalytic activity for the formation of furfural from corn stover. When the MSPFR/corn stover mass loading ratio was 0.5, a higher furfural yield of 43.4% could be achieved at 190 °C in 100 min with 30.7% 5-hydroxymethylfurfural (HMF) yield. Additionally, quite importantly, the recyclability of the MSPFR for xylose dehydration is good, and for the conversion of corn stover was reasonable. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Effects of simulated acid rain on seed germination and seedling growth of different type corn Zea mays].

Science.gov (United States)

Zhang, Hai-Yan

2013-06-01

Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain (pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0). Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 (CK), the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area.

Reducing biomass recalcitrance via mild sodium carbonate pretreatment.

Science.gov (United States)

Mirmohamadsadeghi, Safoora; Chen, Zhu; Wan, Caixia

2016-06-01

This study examined the effects of mild sodium carbonate (Na2CO3) pretreatment on enzymatic hydrolysis of different feedstocks (i.e., corn stover, Miscanthus, and switchgrass). The results showed that sodium carbonate pretreatment markedly enhanced the sugar yields of the tested biomass feedstocks. The pretreated corn stover, Miscanthus, and switchgrass gave the glucose yields of 95.1%, 62.3%, and 81.3%, respectively, after enzymatic hydrolysis. The above glucose yields of pretreated feedstocks were 2-4 times that of untreated ones. The pretreatment also enhanced the xylose yields, 4 times for corn stover and 20 times for both Miscanthus and switchgrass. Sodium carbonate pretreatment removed 40-59% lignin from the tested feedstocks while preserving most of cellulose (sodium carbonate pretreatment was effective for reducing biomass recalcitrance and subsequently improving the digestibility of lignocellulosic biomass. Copyright © 2016 Elsevier Ltd. All rights reserved.

Thermogravimetric study and kinetic analysis of fungal pretreated corn stover using the distributed activation energy model.

Science.gov (United States)

Ma, Fuying; Zeng, Yelin; Wang, Jinjin; Yang, Yang; Yang, Xuewei; Zhang, Xiaoyu

2013-01-01

Non-isothermal thermogravimetry/derivative thermogravimetry (TG/DTG) measurements are used to determine pyrolytic characteristics and kinetics of lignocellulose. TG/DTG experiments at different heating rates with corn stover pretreated with monocultures of Irpex lacteus CD2 and Auricularia polytricha AP and their cocultures were conducted. Heating rates had little effect on the pyrolysis process, but the peak of weight loss rate in the DTG curves shifted towards higher temperature with heating rate. The maximum weight loss of biopretreated samples was 1.25-fold higher than that of the control at the three heating rates, and the maximum weight loss rate of the co-culture pretreated samples was intermediate between that of the two mono-cultures. The activation energies of the co-culture pretreated samples were 16-72 kJ mol(-1) lower than that of the mono-culture at the conversion rate range from 10% to 60%. This suggests that co-culture pretreatment can decrease activation energy and accelerate pyrolysis reaction thus reducing energy consumption. Copyright © 2012 Elsevier Ltd. All rights reserved.

High ethanol yields using Aspergillus oryzae koji and corn media

Energy Technology Data Exchange (ETDEWEB)

Ziffer, J.; Iosif, M.C.

1982-01-01

High ethanol and stillage solids were achieved using whole corn mashes. Ethanol yields of 14% (98.5% of theory) and stillage levels of approximately 23% were obtained in 74-90 hours using mild acid pretreatment with A. oryzae wheat bran koji saccharification. High ethanol yields were also obtained with bacterial amylase, instead of the acid treatment, when the sterilization step was omitted. The implications of ethanol fermentation process modifications are explored.

Enzymatic digestibility and ethanol fermentability of AFEX-treated starch-rich lignocellulosics such as corn silage and whole corn plant

Directory of Open Access Journals (Sweden)

Thelen Kurt D

2010-06-01

Full Text Available Abstract Background Corn grain is an important renewable source for bioethanol production in the USA. Corn ethanol is currently produced by steam liquefaction of starch-rich grains followed by enzymatic saccharification and fermentation. Corn stover (the non-grain parts of the plant is a potential feedstock to produce cellulosic ethanol in second-generation biorefineries. At present, corn grain is harvested by removing the grain from the living plant while leaving the stover behind on the field. Alternatively, whole corn plants can be harvested to cohydrolyze both starch and cellulose after a suitable thermochemical pretreatment to produce fermentable monomeric sugars. In this study, we used physiologically immature corn silage (CS and matured whole corn plants (WCP as feedstocks to produce ethanol using ammonia fiber expansion (AFEX pretreatment followed by enzymatic hydrolysis (at low enzyme loadings and cofermentation (for both glucose and xylose using a cellulase-amylase-based cocktail and a recombinant Saccharomyces cerevisiae 424A (LNH-ST strain, respectively. The effect on hydrolysis yields of AFEX pretreatment conditions and a starch/cellulose-degrading enzyme addition sequence for both substrates was also studied. Results AFEX-pretreated starch-rich substrates (for example, corn grain, soluble starch had a 1.5-3-fold higher enzymatic hydrolysis yield compared with the untreated substrates. Sequential addition of cellulases after hydrolysis of starch within WCP resulted in 15-20% higher hydrolysis yield compared with simultaneous addition of hydrolytic enzymes. AFEX-pretreated CS gave 70% glucan conversion after 72 h of hydrolysis for 6% glucan loading (at 8 mg total enzyme loading per gram glucan. Microbial inoculation of CS before ensilation yielded a 10-15% lower glucose hydrolysis yield for the pretreated substrate, due to loss in starch content. Ethanol fermentation of AFEX-treated (at 6% w/w glucan loading CS hydrolyzate (resulting

Enzymatic digestibility and ethanol fermentability of AFEX-treated starch-rich lignocellulosics such as corn silage and whole corn plant

Science.gov (United States)

2010-01-01

Background Corn grain is an important renewable source for bioethanol production in the USA. Corn ethanol is currently produced by steam liquefaction of starch-rich grains followed by enzymatic saccharification and fermentation. Corn stover (the non-grain parts of the plant) is a potential feedstock to produce cellulosic ethanol in second-generation biorefineries. At present, corn grain is harvested by removing the grain from the living plant while leaving the stover behind on the field. Alternatively, whole corn plants can be harvested to cohydrolyze both starch and cellulose after a suitable thermochemical pretreatment to produce fermentable monomeric sugars. In this study, we used physiologically immature corn silage (CS) and matured whole corn plants (WCP) as feedstocks to produce ethanol using ammonia fiber expansion (AFEX) pretreatment followed by enzymatic hydrolysis (at low enzyme loadings) and cofermentation (for both glucose and xylose) using a cellulase-amylase-based cocktail and a recombinant Saccharomyces cerevisiae 424A (LNH-ST) strain, respectively. The effect on hydrolysis yields of AFEX pretreatment conditions and a starch/cellulose-degrading enzyme addition sequence for both substrates was also studied. Results AFEX-pretreated starch-rich substrates (for example, corn grain, soluble starch) had a 1.5-3-fold higher enzymatic hydrolysis yield compared with the untreated substrates. Sequential addition of cellulases after hydrolysis of starch within WCP resulted in 15-20% higher hydrolysis yield compared with simultaneous addition of hydrolytic enzymes. AFEX-pretreated CS gave 70% glucan conversion after 72 h of hydrolysis for 6% glucan loading (at 8 mg total enzyme loading per gram glucan). Microbial inoculation of CS before ensilation yielded a 10-15% lower glucose hydrolysis yield for the pretreated substrate, due to loss in starch content. Ethanol fermentation of AFEX-treated (at 6% w/w glucan loading) CS hydrolyzate (resulting in 28 g/L ethanol

Connecting Lignin-Degradation Pathway with Pre-Treatment Inhibitor Sensitivity of Cupriavidus necator

Energy Technology Data Exchange (ETDEWEB)

Wang, W. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Yang, S. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hunsinger, G. B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Pienkos, P. T. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Johnson, D. K. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2014-05-27

In order to produce lignocellulosic biofuels economically, the complete release of monomers from the plant cell wall components, cellulose, hemicellulose, and lignin, through pre-treatment and hydrolysis (both enzymatic and chemical), and the efficient utilization of these monomers as carbon sources, is crucial. In addition, the identification and development of robust microbial biofuel production strains that can tolerate the toxic compounds generated during pre-treatment and hydrolysis is also essential. In this work, Cupriavidus necator was selected due to its capabilities for utilizing lignin monomers and producing polyhydroxylbutyrate (PHB), a bioplastic as well as an advanced biofuel intermediate. We characterized the growth kinetics of C. necator in pre-treated corn stover slurry as well as individually in the pre-sence of 11 potentially toxic compounds in the saccharified slurry. We found that C. necator was sensitive to the saccharified slurry produced from dilute acid pre-treated corn stover. Five out of 11 compounds within the slurry were characterized as toxic to C. necator, namely ammonium acetate, furfural, hydroxymethylfurfural (HMF), benzoic acid, and p-coumaric acid. Aldehydes (e.g., furfural and HMF) were more toxic than the acetate and the lignin degradation products benzoic acid and p-coumaric acid; furfural was identified as the most toxic compound. Although toxic to C. necator at high concentration, ammonium acetate, benzoic acid, and p-coumaric acid could be utilized by C. necator with a stimulating effect on C. necator growth. Consequently, the lignin degradation pathway of C. necator was reconstructed based on genomic information and literature. The efficient conversion of intermediate catechol to downstream products of cis,cis-muconate or 2-hydroxymuconate-6-semialdehyde may help improve the robustness of C. necator to benzoic acid and p-coumaric acid as well as improve PHB productivity.

Enzymatic conversion of pretreated biomass into fermentable sugars for biorefinery operation

Science.gov (United States)

Gao, Dahai

2011-12-01

formed during pretreatment impede accurate quantification of individual glycosyl hydrolases (GH) binding to pretreated cell walls. A high-throughput Fast Protein Liquid Chromatography (HT-FPLC) based method has been developed to quantify CBH I, CBH II and EG I present in hydrolyzates of untreated, AFEX, and dilute-acid pretreated corn stover. This method can accurately quantify individual enzymes present in complex binary and ternary protein mixtures without interference from plant cell wall derived components. The binding characteristics of CBH I, CBH II and EG I during 48 hours hydrolysis were studied on different cellulose allomorphs: microcrystalline cellulose Avicel (cellulose Ibeta), liquid ammonia treated cellulose (cellulose III), sodium hydroxide treated cellulose (cellulose II) and phosphoric acid swollen amorphous cellulose (AC). The digestibility ranking is AC>cellulose III>cellulose II>cellulose I. However, AC has the highest initial enzyme binding capacity while cellulose III had the lowest. CBH II is less stable during hydrolysis. Time course binding studies were also performed for pretreated biomass. Ammonia Fiber Expansion (AFEX) treated corn stover (CS), dilute acid (ACID) treated CS and ionic liquid (IL) pretreated CS were compared. The results indicate that presence of lignin is responsible for significant unproductive cellulase binding. These results are critical for improving our understanding of enzyme synergism, productive/unproductive enzyme binding and the role of pretreatment on enzyme accessibility to lignocellulosic plant cell walls. The results also assist in engineering novel low unproductive binding enzyme systems and developing economic enzyme recycle options.

Lipid accumulation by pelletized culture of Mucor circinelloides on corn stover hydrolysate.

Science.gov (United States)

Reis, Cristiano E R; Zhang, Jianguo; Hu, Bo

2014-09-01

Microbial oil accumulated by fungal cells is a potential feedstock for biodiesel production, and lignocellulosic materials can serve as the carbon source to support the fungal growth. The dilute acid pretreatment of corn stover can effectively break down its lignin structure, and this process generates a hydrolysate containing mostly xylose at very dilute concentration and numerous by-products that may significantly inhibit the cell growth. This study utilized corn stover hydrolysate as the culture media for the growth of Mucor circinelloides. The results showed that Mucor cells formed pellets during the cell growth, which facilitates the cell harvest from dilute solution. The results also showed that the inhibitory effect of furfural, 5-hydroxymethylfurfural (HMF), and acetic acid could be avoided if their concentration was low. In fact, all these by-products may be assimilated as carbon sources for the fungal growth. The results proved the feasibility to reuse the cultural broth water for acid pretreatment and then use for subsequent cell cultivation. The results will have a direct impact on the overall water usage of the process.

Simultaneous saccharification and fermentation of alkaline-pretreated corn stover to ethanol using a recombinant yeast strain

Energy Technology Data Exchange (ETDEWEB)

Zhao, Jing; Xia, Liming [Department of Chemical and Biochemical Engineering, Zhejiang University, Hangzhou 310027 (China)

2009-10-15

Bio-ethanol converted from cheap and abundant lignocellulosic materials is a potential renewable resource to replace depleting fossil fuels. Simultaneous saccharification and fermentation (SSF) of alkaline-pretreated corn stover for the production of ethanol was investigated using a recombinant yeast strain Saccharomyces cerevisiae ZU-10. Low cellobiase activity in Trichoderma reesei cellulase resulted in cellobiose accumulation. Supplementing the simultaneous saccharification and fermentation system with cellobiase greatly reduced feedback inhibition caused by cellobiose to the cellulase reaction, thereby increased the ethanol yield. 12 h of enzymatic prehydrolysis at 50 C prior to simultaneous saccharification and fermentation was found to have a negative effect on the overall ethanol yield. Glucose and xylose produced from alkaline-pretreated corn stover could be co-fermented to ethanol effectively by S. cerevisiae ZU-10. An ethanol concentration of 27.8 g/L and the corresponding ethanol yield on carbohydrate in substrate of 0.350 g/g were achieved within 72 h at 33 C with 80 g/L of substrate and enzyme loadings of 20 filter paper activity units (FPU)/g substrate and 10 cellobiase units (CBU)/g substrate. The results are meaningful in co-conversion of cellulose and hemicellulose fraction of lignocellulosic materials to fuel ethanol. (author)

Comparison of gamma irradiation and steam explosion pretreatment for ethanol production from agricultural residues

International Nuclear Information System (INIS)

Wang, Ke-qin; Xiong, Xing-yao; Chen, Jing-ping; Chen, Liang; Su, Xiaojun; Liu, Yun

2012-01-01

It was evaluated the influence of gamma irradiation and steam explosion pretreatment on the components and the water-soluble sugars of rice straw. Compared with the steam explosion pretreated rice straw, cellucose, hemicellucose and lignin for irradiation pretreated rice sample were much more greatly degraded and the relative content of glucose was significantly enhanced from 6.58% to 47.44%. Interestingly, no glucuronide acid was detected in irradiation pretreated rice straw, while glucuronide acid with the content from 8.5 mg/g to 9.2 mg/g was obtained in steam explosion pretreated sample. Followed by enzymatic hydrolysis, higher concentration of reducing sugars (including glucose and xylose) of irradiation pretreated rice sample (90.3 mg/g) was obtained, which was approximately 2.4- and 1.1- fold higher of the unpretreated (37.2 mg/g) and of steam explosion pretreated sample (85.4 mg/g). To further verify the effectiveness of irradiation pretreatment, characterizations of rice straw, corn stalk and bagasse by an integrated process of dilute acid/enzymatic hydrolysis and irradiation pretreatment were also investigated. -- Highlights: ► We compare irradiation and steam explosion pretreatments for bioethanol production. ► We examine changes in compositions of the components and the water-soluble sugars. ► No glucuronide acid was detected in gamma irradiation pretreated rice straw. ► We evaluate an integrated method of acid/enzyme-hydrolyzed irradiation pretreatment.

Sequential high gravity ethanol fermentation and anaerobic digestion of steam explosion and organosolv pretreated corn stover.

Science.gov (United States)

Katsimpouras, Constantinos; Zacharopoulou, Maria; Matsakas, Leonidas; Rova, Ulrika; Christakopoulos, Paul; Topakas, Evangelos

2017-11-01

The present work investigates the suitability of pretreated corn stover (CS) to serve as feedstock for high gravity (HG) ethanol production at solids-content of 24wt%. Steam explosion, with and without the addition of H 2 SO 4 , and organosolv pretreated CS samples underwent a liquefaction/saccharification step followed by simultaneous saccharification and fermentation (SSF). Maximum ethanol concentration of ca. 76g/L (78.3% ethanol yield) was obtained from steam exploded CS (SECS) with 0.2% H 2 SO 4 . Organosolv pretreated CS (OCS) also resulted in high ethanol concentration of ca. 65g/L (62.3% ethanol yield). Moreover, methane production through anaerobic digestion (AD) was conducted from fermentation residues and resulted in maximum methane yields of ca. 120 and 69mL/g volatile solids (VS) for SECS and OCS samples, respectively. The results indicated that the implementation of a liquefaction/saccharification step before SSF employing a liquefaction reactor seemed to handle HG conditions adequately. Copyright © 2017 Elsevier Ltd. All rights reserved.

Potential of Black Liquor of Potassium Hydroxide to Pretreat Corn Stover for Biomethane Production

Directory of Open Access Journals (Sweden)

Muhammad Abdul Hanan Siddhu

2016-04-01

Full Text Available Reducing the pretreatment cost of lignocellulosic biomass by utilizing alkali to alter its recalcitrant nature is an effective method for biofuel production. In this experiment, 1.5% KOH solution and its black liquor (spent liquor of KOH (BL were applied to pretreat corn stover (CS at a temperature of 20 °C to enhance the digestibility for anaerobic digestion (AD. Results showed no significant difference in weighted average methane content on the basis of experimental methane and biogas yields between BL-treated and original KOH-treated CS after AD. The BL process significantly increased the overall methane yield by 52.4% compared with untreated CS (135.2 mL/gVS, whereas no significant difference between the overall methane yields of 1.5% KOH-treated and BL-treated CS was observed. In addition, the BL process significantly saved water and KOH consumption, by 56.2% and 57.4%, respectively, compared with the 1.5% KOH pretreatment. Overall methane production was well explained by the modified Gompertz model. The physiochemical changes to CS after BL pretreatment were confirmed by SEM, FTIR, and XRD analyses. Our findings collectively suggest that recycling and reuse of KOH black liquor might be an efficient method for lignocellulosic biomass treatment and have the capability to reduce input costs in future AD processes.

Improved ethanol yield and reduced Minimum Ethanol Selling Price (MESP by modifying low severity dilute acid pretreatment with deacetylation and mechanical refining: 1 Experimental

Directory of Open Access Journals (Sweden)

Chen Xiaowen

2012-08-01

Full Text Available Abstract Background Historically, acid pretreatment technology for the production of bio-ethanol from corn stover has required severe conditions to overcome biomass recalcitrance. However, the high usage of acid and steam at severe pretreatment conditions hinders the economic feasibility of the ethanol production from biomass. In addition, the amount of acetate and furfural produced during harsh pretreatment is in the range that strongly inhibits cell growth and impedes ethanol fermentation. The current work addresses these issues through pretreatment with lower acid concentrations and temperatures incorporated with deacetylation and mechanical refining. Results The results showed that deacetylation with 0.1 M NaOH before acid pretreatment improved the monomeric xylose yield in pretreatment by up to 20% while keeping the furfural yield under 2%. Deacetylation also improved the glucose yield by 10% and the xylose yield by 20% during low solids enzymatic hydrolysis. Mechanical refining using a PFI mill further improved sugar yields during both low- and high-solids enzymatic hydrolysis. Mechanical refining also allowed enzyme loadings to be reduced while maintaining high yields. Deacetylation and mechanical refining are shown to assist in achieving 90% cellulose yield in high-solids (20% enzymatic hydrolysis. When fermentations were performed under pH control to evaluate the effect of deacetylation and mechanical refining on the ethanol yields, glucose and xylose utilizations over 90% and ethanol yields over 90% were achieved. Overall ethanol yields were calculated based on experimental results for the base case and modified cases. One modified case that integrated deacetylation, mechanical refining, and washing was estimated to produce 88 gallons of ethanol per ton of biomass. Conclusion The current work developed a novel bio-ethanol process that features pretreatment with lower acid concentrations and temperatures incorporated with deacetylation

Improvement of enzymatic hydrolysis and ethanol production from corn stalk by alkali and N-methylmorpholine-N-oxide pretreatments.

Science.gov (United States)

Cai, Ling-Yan; Ma, Yu-Long; Ma, Xiao-Xia; Lv, Jun-Min

2016-07-01

A combinative technology of alkali and N-methylmorpholine-N-oxide (NMMO) was used to pretreat corn stalk (CS) for improving the efficiencies of subsequent enzymatic hydrolysis and ethanol fermentation. The results showed that this strategy could not only remove hemicellulose and lignin but also decrease the crystallinity of cellulose. About 98.0% of enzymatic hydrolysis yield was obtained from the pretreated CS as compared with 46.9% from the untreated sample. The yield for corresponding ethanol yield was 64.6% while untreated CS was only 18.8%. Besides, xylose yield obtained from the untreated CS was only 11.1%, while this value was 93.8% for alkali with NMMO pretreated sample. These results suggest that a combination of alkali with 50% (wt/wt) NMMO solution may be a promising alternative for pretreatment of lignocellulose, which can increase the productions of subsequent enzymatic hydrolysis and ethanol fermentation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Improved biomass degradation using fungal glucuronoyl-esterases-hydrolysis of natural corn fiber substrate

DEFF Research Database (Denmark)

d'Errico, Clotilde; Börjesson, Johan; Ding, Hanshu

2016-01-01

of improved degradation of lignocellulosic biomass by the use of GEs. Improved C5 sugar, glucose and glucuronic acid release was observed when heat pretreated corn fiber was incubated in the presence of GEs from Cerrena unicolor and Trichoderma reesei on top of different commercial cellulase...

Comparison of the Effects of Thermal Pretreatment, Steam Explosion and Ultrasonic Disintegration on Digestibility of Corn Stover

OpenAIRE

Andras Dallos; Gyula Dörgő; Dániel Capári

2016-01-01

The energy demand of the corn-based bioethanol production could be reduced using the agricultural byproducts as bioenergy feedstock for biogas digesters. The release of lignocellulosic material and therefore the acceleration of degradation processes can be achieved using thermal and mechanical pretreatments, which assist to hydrolyze the cell walls and speed the solubilization of biopolymers in biogas feedstock. This study is focused on liquid hot water, steam explosion and ultrasonic pretrea...

Kinetic study of dilute nitric acid treatment of corn stover at relatively high temperature

Energy Technology Data Exchange (ETDEWEB)

Zhang, R.; Lu, X.; Liu, Y.; Wang, X.; Zhang, S. [Tianjin University, School of Environmental Science and Technology, Tianjin (China)

2011-03-15

Corn stover was hydrolyzed using dilute nitric acid at 150 C. Several concentrations of HNO{sub 3} (0.2, 0.4 and 0.6 wt-%) and reaction times (0-60 min) were evaluated. The kinetic parameters of mathematical models for predicting the concentrations of xylose, glucose, arabinose, acetic acid, and furfural in the hydrolysates were determined. The hydrolysates obtained from corn stover can be used to produce methane by an anaerobic fermentation process. Thus, the hydrolysis process of corn stover using dilute nitric acid can be conceived as the first stage of an integrated strategy for corn stover utilization. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Study of Enzymatic Hydrolysis of Dilute Acid Pretreated Coconut Husk

Directory of Open Access Journals (Sweden)

Rudy Agustriyanto

2012-12-01

Full Text Available Coconut husk is classified as complex lignocellulosic material that contains cellulose, hemicellulose, lignin, and some other extractive compounds. Cellulose from coconut husk can be used as fermentation substrate after enzymatic hydrolysis. In contrary, lignin content from the coconut husk will act as an inhibitor in this hydrolysis process. Therefore, a pretreatment process is needed to enhance the hydrolysis of cellulose. The objective of this research is to investigate the production of the glucose through dilute acid pretreatment and to obtain its optimum operating conditions. In this study, the pretreatment was done using dilute sulfuric acid in an autoclave reactor. The pretreatment condition were varied at 80°C, 100°C, 120°C and 0.9%, 1.2%, 1.5% for temperature and acid concentration respectively. The acid pretreated coconut husk was then hydrolyzed using commercial cellulase (celluclast and β-glucosidase (Novozyme 188. The hydrolysis time was 72 hours and the operating conditions were varied at several temperature and pH. From the experimental results it can be concluded that the delignification temperature variation has greater influence than the acid concentration. The optimum operating condition was obtained at pH 4 and 50°C which was pretreated at 100°C using 1.5% acid concentration. Copyright © 2012 by BCREC UNDIP. All rights reserved. (Selected Paper from International Conference on Chemical and Material Engineering (ICCME 2012Received: 28th September 2012, Revised: 2nd October 2012, Accepted: 4th October 2012[How to Cite: R. Agustriyanto, A. Fatmawati, Y. Liasari. (2012. Study of Enzymatic Hydrolysis of Dilute Acid Pretreated Coconut Husk. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 137-141. doi:10.9767/bcrec.7.2.4046.137-141] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.4046.137-141 ] | View in 

Comparison of ethanol production from corn cobs and switchgrass following a pyrolysis-based biorefinery approach.

Science.gov (United States)

Luque, Luis; Oudenhoven, Stijn; Westerhof, Roel; van Rossum, Guus; Berruti, Franco; Kersten, Sascha; Rehmann, Lars

2016-01-01

One of the main obstacles in lignocellulosic ethanol production is the necessity of pretreatment and fractionation of the biomass feedstocks to produce sufficiently pure fermentable carbohydrates. In addition, the by-products (hemicellulose and lignin fraction) are of low value, when compared to dried distillers grains (DDG), the main by-product of corn ethanol. Fast pyrolysis is an alternative thermal conversion technology for processing biomass. It has recently been optimized to produce a stream rich in levoglucosan, a fermentable glucose precursor for biofuel production. Additional product streams might be of value to the petrochemical industry. However, biomass heterogeneity is known to impact the composition of pyrolytic product streams, as a complex mixture of aromatic compounds is recovered with the sugars, interfering with subsequent fermentation. The present study investigates the feasibility of fast pyrolysis to produce fermentable pyrolytic glucose from two abundant lignocellulosic biomass sources in Ontario, switchgrass (potential energy crop) and corn cobs (by-product of corn industry). Demineralization of biomass removes catalytic centers and increases the levoglucosan yield during pyrolysis. The ash content of biomass was significantly decreased by 82-90% in corn cobs when demineralized with acetic or nitric acid, respectively. In switchgrass, a reduction of only 50% for both acids could be achieved. Conversely, levoglucosan production increased 9- and 14-fold in corn cobs when rinsed with acetic and nitric acid, respectively, and increased 11-fold in switchgrass regardless of the acid used. After pyrolysis, different configurations for upgrading the pyrolytic sugars were assessed and the presence of potentially inhibitory compounds was approximated at each step as double integral of the UV spectrum signal of an HPLC assay. The results showed that water extraction followed by acid hydrolysis and solvent extraction was the best upgrading strategy

Lignocellulosic Biomass Pretreatment Using AFEX

Science.gov (United States)

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

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.

Succinic Acid as a Byproduct in a Corn-based Ethanol Biorefinery

Energy Technology Data Exchange (ETDEWEB)

MBI International

2007-12-31

MBI endeavored to develop a process for succinic acid production suitable for integration into a corn-based ethanol biorefinery. The project investigated the fermentative production of succinic acid using byproducts of corn mill operations. The fermentation process was attuned to include raw starch, endosperm, as the sugar source. A clean-not-sterile process was established to treat the endosperm and release the monomeric sugars. We developed the fermentation process to utilize a byproduct of corn ethanol fermentations, thin stillage, as the source of complex nitrogen and vitamin components needed to support succinic acid production in A. succinogenes. Further supplementations were eliminated without lowering titers and yields and a productivity above 0.6 g l-1 hr-1was achieved. Strain development was accomplished through generation of a recombinant strain that increased yields of succinic acid production. Isolation of additional strains with improved features was also pursued and frozen stocks were prepared from enriched, characterized cultures. Two recovery processes were evaluated at pilot scale and data obtained was incorporated into our economic analyses.

Phosphorus and short-chain fatty acids recovery from waste activated sludge by anaerobic fermentation: Effect of acid or alkali pretreatment.

Science.gov (United States)

Wu, Liang; Zhang, Cheng; Hu, Hui; Liu, Jianyong; Duan, Tengfei; Luo, Jinghuan; Qian, Guangren

2017-09-01

Waste activated sludge (WAS) was pretreated by acid or alkali to enhance the anaerobic fermentation (AF) for phosphorus (P) and short-chain fatty acids (SCFAs) release into the liquid simultaneously. With acid pretreatment, the released total P concentration achieved 120mg/L, which was 71.4% higher than that with alkali pretreatment. In addition, alkali pretreatment enhanced organic P release with about 35.3% of organic P in the solid being converted to inorganic P, while little had changed with acid pretreatment. The results also showed that acid and alkali pretreatment enhanced SCFAs production by 15.3 and 12.5times, respectively. Acid pretreatment could be preferred for simultaneous recovery of P and SCFAs by AF. Copyright © 2017 Elsevier Ltd. All rights reserved.

Efficacy of pretreating oil palm fronds with an acid-base mixture catalyst.

Science.gov (United States)

Jung, Young Hoon; Park, Hyun Min; Park, Yong-Cheol; Park, Kyungmoon; Kim, Kyoung Heon

2017-07-01

Oil palm fronds are abundant but recalcitrant to chemical pretreatment. Herein, an acid-base mixture was applied as a catalyst to efficiently pretreat oil palm fronds. Optimized conditions for the pretreatment were a 0.1M acidic acid-base mixture and 3min ramping to 190°C and 12min holding. The oil palm fronds pretreated and washed with the acid-base mixture exhibited an enzymatic digestibility of 85% by 15 FPU Accellerase 1000/g glucan after 72h hydrolysis, which was significantly higher than the enzymatic digestibilities obtained by acid or alkali pretreatment alone. This could be attributed to the synergistic actions of the acid and base, producing an 87% glucose recovery with 100% and 40.3% removal of xylan and lignin, respectively, from the solids. Therefore, an acid-base mixture can be a feasible catalyst to deconstruct oil palm fronds for sugar production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Supplementation with xylanase and β-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover

Science.gov (United States)

2011-01-01

Background Hemicellulose is often credited with being one of the important physical barriers to enzymatic hydrolysis of cellulose, and acts by blocking enzyme access to the cellulose surface. In addition, our recent research has suggested that hemicelluloses, particularly in the form of xylan and its oligomers, can more strongly inhibit cellulase activity than do glucose and cellobiose. Removal of hemicelluloses or elimination of their negative effects can therefore become especially pivotal to achieving higher cellulose conversion with lower enzyme doses. Results In this study, cellulase was supplemented with xylanase and β-xylosidase to boost conversion of both cellulose and hemicellulose in pretreated biomass through conversion of xylan and xylo-oligomers to the less inhibitory xylose. Although addition of xylanase and β-xylosidase did not necessarily enhance Avicel hydrolysis, glucan conversions increased by 27% and 8% for corn stover pretreated with ammonia fiber expansion (AFEX) and dilute acid, respectively. In addition, adding hemicellulase several hours before adding cellulase was more beneficial than later addition, possibly as a result of a higher adsorption affinity of cellulase and xylanase to xylan than glucan. Conclusions This key finding elucidates a possible mechanism for cellulase inhibition by xylan and xylo-oligomers and emphasizes the need to optimize the enzyme formulation for each pretreated substrate. More research is needed to identify advanced enzyme systems designed to hydrolyze different substrates with maximum overall enzyme efficacy. PMID:21702938

The Effect of Acid Pre-Treatment using Acetic Acid and Nitric Acid in The Production of Biogas from Rice Husk during Solid State Anaerobic Digestion (SS-AD)

Science.gov (United States)

Nugraha, Winardi Dwi; Syafrudin; Keumala, Cut Fadhila; Matin, Hasfi Hawali Abdul; Budiyono

2018-02-01

Pretreatment during biogas production aims to assist in degradation of lignin contained in the rice husk. In this study, pretreatment which is used are acid and biological pretreatment. Acid pretreatment was performed using acetic acid and nitric acid with a variety levels of 3% and 5%. While biological pretreatment as a control variable. Acid pretreatment was conducted by soaking the rice straw for 24 hours with acid variation. The study was conducted using Solid State Anaerobic Digestion (SS-AD) with 21% TS. Biogas production was measured using water displacement method every two days for 60 days at room temperature conditions. The results showed that acid pretreatment gave an effect on the production of biogas yield. The yield of the biogas produced by pretreatment of acetic acid of 5% and 3% was 43.28 and 45.86 ml/gr.TS. While the results without pretreatment biogas yield was 29.51 ml/gr.TS. The results yield biogas produced by pretreatment using nitric acid of 5% and 3% was 12.14 ml/gr.TS and 21.85 ml/gr.TS. Results biogas yield with acetic acid pretreatment was better than the biogas yield results with nitric acid pretreatment.

Valorization of lignin and cellulose in acid-steam-exploded corn stover by a moderate alkaline ethanol post-treatment based on an integrated biorefinery concept.

Science.gov (United States)

Yang, Sheng; Zhang, Yue; Yue, Wen; Wang, Wei; Wang, Yun-Yan; Yuan, Tong-Qi; Sun, Run-Cang

2016-01-01

Due to the unsustainable consumption of fossil resources, great efforts have been made to convert lignocellulose into bioethanol and commodity organic compounds through biological methods. The conversion of cellulose is impeded by the compactness of plant cell wall matrix and crystalline structure of the native cellulose. Therefore, appropriate pretreatment and even post-treatment are indispensable to overcome this problem. Additionally, an adequate utilization of coproduct lignin will be important for improving the economic viability of modern biorefinery industries. The effectiveness of moderate alkaline ethanol post-treatment on the bioconversion efficiency of cellulose in the acid-steam-exploded corn stover was investigated in this study. Results showed that an increase of the alcoholic sodium hydroxide (NaOH) concentration from 0.05 to 4% led to a decrease in the lignin content in the post-treated samples from 32.8 to 10.7%, while the cellulose digestibility consequently increased. The cellulose conversion of the 4% alcoholic NaOH integrally treated corn stover reached up to 99.3% after 72 h, which was significantly higher than that of the acid steam exploded corn stover without post-treatment (57.3%). In addition to the decrease in lignin content, an expansion of cellulose I lattice induced by the 4% alcoholic NaOH post-treatment played a significant role in promoting the enzymatic hydrolysis of corn stover. More importantly, the lignin fraction (AL) released during the 4% alcoholic NaOH post-treatment and the lignin-rich residue (EHR) remained after the enzymatic hydrolysis of the 4% alcoholic NaOH post-treated acid-steam-exploded corn stover were employed to synthesize lignin-phenol-formaldehyde (LPF) resins. The plywoods prepared with the resins exhibit satisfactory performances. An alkaline ethanol system with an appropriate NaOH concentration could improve the removal of lignin and modification of the crystalline structure of cellulose in acid

Sugar yields from dilute oxalic acid pretreatment of maple wood compared to those with other dilute acids and hot water.

Science.gov (United States)

Zhang, Taiying; Kumar, Rajeev; Wyman, Charles E

2013-01-30

Dilute oxalic acid pretreatment was applied to maple wood to improve compatibility with downstream operations, and its performance in pretreatment and subsequent enzymatic hydrolysis was compared to results for hydrothermal and dilute hydrochloric and sulfuric acid pretreatments. The highest total xylose yield of ∼84% of the theoretical maximum was for both 0.5% oxalic and sulfuric acid pretreatment at 160 °C, compared to ∼81% yield for hydrothermal pretreatment at 200 °C and for 0.5% hydrochloric acid pretreatment at 140 °C. The xylooligomer fraction from dilute oxalic acid pretreatment was only 6.3% of the total xylose in solution, similar to results with dilute hydrochloric and sulfuric acids but much lower than the ∼70% value for hydrothermal pretreatment. Combining any of the four pretreatments with enzymatic hydrolysis with 60 FPU cellulase/g of glucan plus xylan in the pretreated maple wood resulted in virtually the same total glucose plus xylose yields of ∼85% of the maximum possible. Copyright © 2012 Elsevier Ltd. All rights reserved.

Co-solvent pretreatment reduces costly enzyme requirements for high sugar and ethanol yields from lignocellulosic biomass.

Science.gov (United States)

Nguyen, Thanh Yen; Cai, Charles M; Kumar, Rajeev; Wyman, Charles E

2015-05-22

We introduce a new pretreatment called co-solvent-enhanced lignocellulosic fractionation (CELF) to reduce enzyme costs dramatically for high sugar yields from hemicellulose and cellulose, which is essential for the low-cost conversion of biomass to fuels. CELF employs THF miscible with aqueous dilute acid to obtain up to 95 % theoretical yield of glucose, xylose, and arabinose from corn stover even if coupled with enzymatic hydrolysis at only 2 mgenzyme  gglucan (-1) . The unusually high saccharification with such low enzyme loadings can be attributed to a very high lignin removal, which is supported by compositional analysis, fractal kinetic modeling, and SEM imaging. Subsequently, nearly pure lignin product can be precipitated by the evaporation of volatile THF for recovery and recycling. Simultaneous saccharification and fermentation of CELF-pretreated solids with low enzyme loadings and Saccharomyces cerevisiae produced twice as much ethanol as that from dilute-acid-pretreated solids if both were optimized for corn stover. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hydrolysis of dilute acid-pretreated cellulose under mild hydrothermal conditions.

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Chimentão, R J; Lorente, E; Gispert-Guirado, F; Medina, F; López, F

2014-10-13

The hydrolysis of dilute acid-pretreated cellulose was investigated in a conventional oven and under microwave heating. Two acids--sulfuric and oxalic--were studied. For both hydrothermal conditions (oven and microwave) the resultant total organic carbon (TOC) values obtained by the hydrolysis of the cellulose pretreated with sulfuric acid were higher than those obtained by the hydrolysis of the cellulose pretreated with oxalic acid. However, the dicarboxylic acid exhibited higher hydrolytic efficiency towards glucose. The hydrolysis of cellulose was greatly promoted by microwave heating. The Rietveld method was applied to fit the X-ray patterns of the resultant cellulose after hydrolysis. Oxalic acid preferentially removed the amorphous region of the cellulose and left the crystalline region untouched. On the other hand, sulfuric acid treatment decreased the ordering of the cellulose by partially disrupting its crystalline structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Acid Pretreatment of Sago Wastewater for Biohydrogen Production

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Illi Mohamad Puad, Noor; Rahim, Nurainin Farhan Abd; Suhaida Azmi, Azlin

2018-03-01

Biohydrogen has been recognized to be one of the future renewable energy sources and has the potential in solving the greenhouse effects. In this study, Enterobacter aerogenes (E. aerogenes) was used as the biohydrogen producer via dark fermentation process using sago wastewater as the substrate. However, pretreatment of sago wastewater is required since it consists of complex sugars that cannot be utilized directly by the bacteria. This study aimed to use acid pretreatment method to produce high amount of glucose from sago wastewater. Three different types of acid: sulfuric acid (H2SO4); hydrochloric acid (HCl) and nitric acid (HNO3) were screened for the best acid in producing a maximum amount of glucose. H2SO4 gave the highest amount of glucose which was 9.406 g/L. Design of experiment was done using Face-centred Central Composite Design (FCCCD) tool under Response Surface Methodology (RSM) in Design Expert 9 software. The maximum glucose (9.138 g/L) was recorded using 1 M H2SO4 at 100 °C for 60 min. A batch dark fermentation using E. aerogenes was carried out and it was found that pretreated sago wastewater gave a higher hydrogen concentration (1700 ppm) compared to the raw wastewater (410 ppm).

Enhancement of enzymatic hydrolysis of corn stover by γ-irradiation and combined solvent delignification/acid prehydrolysis

International Nuclear Information System (INIS)

Nghiem, N.P.; Gonzales-Valdes, A.; Moo-Young, M.; Robinson, C.W.

1984-01-01

Two pretreatment schemes were studied for their effect on the enhancement of soluble sugar production from corn stover by enzymatic hydrolysis. In the first scheme, prior to enzymic hydrolysis corn stover which was ground to pass a 1 mm screen was immersed in NaOH solution and exposed to gamma irradiation. The NaOH levels and radiation dosages were varied from 0 to 0.51 gNaOH/g corn stover and from 50 to 150 Mr, respectively. The combined residue and solubles were then hydrolyzed with a commercial cellulase (Onozuka) in 0.05 M citrate buffer at pH 4.6 and 39 0 C for 48 hours. The highest sugar yield of 96% based on the total carbohydrate content of the original sample was obtained at 100 Mr and 0.06 gNaOH/g corn stover. In the second scheme, corn stover which was ground to pass a 0.35 mm screen was delignified with ethanol-water-NaOH. The ethanol-water mixture used contained 3 parts (by volume) of 95% ethanol and 4 g NaOH/L; substrate concentration was 5% (w/v). The delignification was carried out at 140 0 C for 1 hour. At these conditions, 65% of the lignin was removed while 90% of the carbohydrates remained insoluble. The delignified corn stover with an without treatment using 2% wt.% H 2 SO 4 at 95 0 C and 1 hour was then enzymically hydrolyzed with Novo Cellulclast at pH 4.8 and 50 0 C for up to 48 hours. Factors that affect the overall sugar production are presented and discussed. In addition, the overall sugar yields for the two schemes are compared with other pretreatment schemes reported. (orig.)

Radiation pretreatment of cellulose for energy production

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Dela Rosa, A. M.; Dela Mines, A. S.; Banzon, R. B.; Simbul-Nuguid, Z. F.

The effect of radiation pretreatment of agricultural cellulosic wastes was investigated through hydrolytic reactions of cellulose. Gamma irradiation significantly increased the acid hydrolysis of rice straw, rice hull and corn husk. The yields of reducing sugar were higher with increasing radiation dose in these materials. The observed radiation effect varied with the cellulosic material but it correlated with neither the cellulose content nor the lignin content. Likewise, the radiation pretreatment accelerated the subsequent enzymatic hydrolysis of rice straw and rice hull by cellulase. The irradiated rice straw appeared to be a better growth medium for the cellulolytic microorganism, Myrothecium verrucaria, than the non-irradiated material. This was attributed to increased digestibility of the cellulose by the microorganism.

Radiation pretreatment of cellulose for energy production

International Nuclear Information System (INIS)

Dela Rosa, A.M.; Dela Mines, A.S.; Banzon, R.B.; Simbul-Nuguid, Z.F.

1983-01-01

The effect of radiation pretreatment of agricultural cellulosic wastes was investigated through hydrolytic reactions of cellulose. Gamma irradiation significantly increased the acid hydrolysis of rice straw, rice hull and corn husk. The yields of reducing sugar were higher with increasing radiation dose in these materials. The observed radiation effect varied with the cellulose material but it correlated with neither the cellulose content nor the lignin content. Likewise, the radiation pretreatment accelerated the subsequent enzymatic hydrolysis of rice straw and rice hull by cellulase. The irradiated rice straw appeared to be a better growth medium for the cellulolytic microorganism, Myrothecium verrucaria, than the non-irradiated material. This was attributed to increased digestibility of the cellulose by the microorganism. (author)

Kinetic characterization for hemicellulose hydrolysis of corn stover in a dilute acid cycle spray flow-through reactor at moderate conditions

International Nuclear Information System (INIS)

Jin, Qiang; Zhang, Hongman; Yan, Lishi; Qu, Liang; Huang, He

2011-01-01

The kinetic characterization of hemicellulose hydrolysis of corn stover was investigated using a new reactor of dilute acid cycle spray flow-through (DCF) pretreatment. The primary purpose was to obtain kinetic data for hemicellulose hydrolysis with sulfuric acid concentrations (10-30 kg m -3 ) at relatively low temperatures (90-100 o C). A simplified kinetic model was used to describe its performance at moderate conditions. The results indicate that the rates of xylose formation and degradation are sensitive to flow rate, temperature and acid concentration. Moreover, the kinetic data of hemicellulose hydrolysis fit a first-order reaction model and the experimental data with actual acid concentration after accounting for the neutralization effect of the substrates at different temperatures. Over 90% of the xylose monomer yield and below 5.5% of degradation product (furfural) yield were observed in this reactor. Kinetic constants for hemicellulose hydrolysis models were analyzed by an Arrhenius-type equation, and the activation energy of xylose formation were 111.6 kJ mol -1 , and 95.7 kJ mol -1 for xylose degradation, respectively. -- Highlights: → Investigating a novel pretreatment reactor of dilute acid cycle spray flow-through. → Xylose yield is sensitive to flow rate, temperature and acid concentration. → Obtaining relatively higher xylose monomer yield and lower fermentation inhibitor. → Lumping hemicellulose and xylan oligmers together in the model is a valid way. → The kinetic model as a guide for reactor design, and operation strategy optimization.

Conversion of Aqueous Ammonia-Treated Corn Stover to Lactic Acid by Simultaneous Saccharification and Cofermentation

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Zhu, Yongming; Lee, Y. Y.; Elander, Richard T.

Treatment of corn stover with aqueous ammonia removes most of the structural lignin, whereas retaining the majority of the carbohydrates in the solids. After treatment, both the cellulose and hemicellulose in corn stover become highly susceptible to enzymatic digestion. In this study, corn stover treated by aqueous ammonia was investigated as the substrate for lactic acid production by simultaneous saccharification and cofermentation (SSCF). A commercial cellulase (Spezyme-CP) and Lactobacillus pentosus American Type Culture Collection (ATCC) 8041 (Spanish Type Culture Collection [CECT]-4023) were used for hydrolysis and fermentation, respectively. In batch SSCF operation, the carbohydrates in the treated corn stover were converted to lactic acid with high yields, the maximum lactic acid yield reaching 92% of the stoichiometric maximum based on total fermentable carbohydrates (glucose, xylose, and arabinose). A small amount of acetic acid was also produced from pentoses through the phosphoketolase pathway. Among the major process variables for batch SSCF, enzyme loading and the amount of yeast extract were found to be the key factors affecting lactic acid production. Further tests on nutrients indicated that corn steep liquor could be substituted for yeast extract as a nitrogen source to achieve the same lactic acid yield. Fed-batch operation of the SSCF was beneficial in raising the concentration of lactic acid to a maximum value of 75.0 g/L.

Simultaneous saccharification and co-fermentation of peracetic acid pretreated sugar cane bagasse

Energy Technology Data Exchange (ETDEWEB)

Teixeira, L.C. [Fundacao Centro Tecnologico de Minas Gerais, Belo Horizonte (Brazil); Linden, J.C.; Schroeder, H.A. [Colorado State University, Fort Collins, CO (United States)

1999-07-01

Previous work in our laboratory has demonstrated that peracetic acid improves the enzymatic digestibility of lignocellulosic materials. From the same studies, use of dilute alkali solutions as a pre-pretreatment prior to peracetic acid lignin oxidation increases sugar conversion yields in a synergistic, not additive, manner. Deacetylation of xylan is conducted easily by use of dilute alkali solutions at mild conditions. In this paper, the effectiveness of peracetic acid pretreatment of sugar cane bagasse combined with an alkaline pre-pretreatment, is evaluated through simultaneous saccharification and co-fermentation (SSCF) procedures. A practical 92% of theoretical ethanol yield using recombinant Zymomonas mobilis CP4/pZB5 is achieved using 6% NaOH/I5% peracetic acid pretreated substrate. No sugar accumulation is observed during SSCF; the recombinant microorganism exhibits greater glucose utilization rates than those of xylose. Acetate levels at the end of the co-fermentations are less than 0.2% (w/v). Based on demonstrated reduction of acetyl groups of the biomass, alkaline pre-pretreatments help to reduce peracetic acid requirements. The influence of deacetylation is more pronounced in combined pretreatments using lower peracetic acid loadings. Stereochemical impediments of the acetyl groups in hemicellulase on the activity of specific enzymes may be involved. (author)

Supplementation with xylanase and β-xylosidase to reduce xylo-oligomer and xylan inhibition of enzymatic hydrolysis of cellulose and pretreated corn stover

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Qing Qing

2011-06-01

Full Text Available Abstract Background Hemicellulose is often credited with being one of the important physical barriers to enzymatic hydrolysis of cellulose, and acts by blocking enzyme access to the cellulose surface. In addition, our recent research has suggested that hemicelluloses, particularly in the form of xylan and its oligomers, can more strongly inhibit cellulase activity than do glucose and cellobiose. Removal of hemicelluloses or elimination of their negative effects can therefore become especially pivotal to achieving higher cellulose conversion with lower enzyme doses. Results In this study, cellulase was supplemented with xylanase and β-xylosidase to boost conversion of both cellulose and hemicellulose in pretreated biomass through conversion of xylan and xylo-oligomers to the less inhibitory xylose. Although addition of xylanase and β-xylosidase did not necessarily enhance Avicel hydrolysis, glucan conversions increased by 27% and 8% for corn stover pretreated with ammonia fiber expansion (AFEX and dilute acid, respectively. In addition, adding hemicellulase several hours before adding cellulase was more beneficial than later addition, possibly as a result of a higher adsorption affinity of cellulase and xylanase to xylan than glucan. Conclusions This key finding elucidates a possible mechanism for cellulase inhibition by xylan and xylo-oligomers and emphasizes the need to optimize the enzyme formulation for each pretreated substrate. More research is needed to identify advanced enzyme systems designed to hydrolyze different substrates with maximum overall enzyme efficacy.

Dilute acid pretreatment of rye straw and bermudagrass for ethanol production

Energy Technology Data Exchange (ETDEWEB)

Ye Sun; Jay J Cheng [North Carolina State Univ., Dept. of Biological and Agricultural Engineering, Raleigh, NC (United States)

2005-09-01

Ethanol production from lignocellulosic materials provides an alternative energy production system. Rye and bermudagrass that are used in hog farms for nutrient uptake from swine wastewater have the potential for fuel ethanol production because they have a relative high cellulose and hemicellulose content. Dilute sulfuric acid pretreatment of rye straw and bermudagrass before enzymatic hydrolysis of cellulose was investigated in this study. The biomass at a solid loading rate of 10% was pretreated at 121 deg C with different sulfuric acid concentrations (0.6, 0.9, 1.2 and 1.5%, w/w) and residence times (30, 60, and 90 min). Total reducing sugars, arabinose, galactose, glucose, and xylose in the prehydrolyzate were analyzed. In addition, the solid residues were hydrolyzed by cellulases to investigate the enzymatic digestibility. With the increasing acid concentration and residence time, the amount of arabinose and galactose in the filtrates increased. The glucose concentration in the prehydrolyzate of rye straw was not significantly influenced by the sulfuric acid concentration and residence time, but it increased in the prehydrolyzate of bermudagrass with the increase of pretreatment severity. The xylose concentration in the filtrates increased with the increase of sulfuric acid concentration and residence time. Most of the arabinan, galactan and xylan in the biomass were hydrolyzed during the acid pretreatment. Cellulose remaining in the pretreated feedstock was highly digestible by cellulases from Trichoderma reesei. (Author)

PRETREATMENT TECHNOLOGIES IN BIOETHANOL PRODUCTION FROM LIGNOCELLULOSIC BIOMASS

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Vanja Janušić

2008-07-01

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.

Effects of thermo-chemical pretreatment plus microbial fermentation and enzymatic hydrolysis on saccharification and lignocellulose degradation of corn straw.

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Wang, Ping; Chang, Juan; Yin, Qingqiang; Wang, Erzhu; Zhu, Qun; Song, Andong; Lu, Fushan

2015-10-01

In order to increase corn straw degradation, the straw was kept in the combined solution of 15% (w/w) lime supernatant and 2% (w/w) sodium hydroxide with liquid-to-solid ratio of 13:1 (mL/g) at 83.92°C for 6h; and then added with 3% (v/v) H2O2 for reaction at 50°C for 2h; finally cellulase (32.3 FPU/g dry matter) and xylanase (550 U/g dry matter) was added to keep at 50°C for 48 h. The maximal reducing sugars yield (348.77 mg/g) was increased by 126.42% (Pcellulose, hemicellulose and lignin in pretreated corn straw with enzymatic hydrolysis were increased by 40.08%, 45.71% and 52.01%, compared with the native corn straw with enzymatic hydrolysis (P<0.05). The following study indicated that the combined microbial fermentation and enzymatic hydrolysis could further increase straw degradation and reducing sugar yield (442.85 mg/g, P<0.05). Copyright © 2015 Elsevier Ltd. All rights reserved.

Improving the conversion of biomass in catalytic fast pyrolysis via white-rot fungal pretreatment.

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Yu, Yanqing; Zeng, Yelin; Zuo, Jiane; Ma, Fuying; Yang, Xuewei; Zhang, Xiaoyu; Wang, Yujue

2013-04-01

This study investigated the effect of white-rot fungal pretreatment on corn stover conversion in catalytic fast pyrolysis (CFP). Corn stover pretreated by white-rot fungus Irpex lacteus CD2 was fast pyrolyzed alone (non-CFP) and with ZSM-5 zeolite (CFP) in a semi-batch pyroprobe reactor. The fungal pretreatment considerably increased the volatile product yields (predominantly oxygenated compounds) in non-CFP, indicating that fungal pretreatment enhances the corn stover conversion in fast pyrolysis. In the presence of ZSM-5 zeolite, these oxygenated volatiles were further catalytically converted to aromatic hydrocarbons, whose yield increased from 10.03 wt.% for the untreated corn stover to 11.49 wt.% for the pretreated sample. In contrast, the coke yield decreased from 14.29 to 11.93 wt.% in CFP following the fungal pretreatment. These results indicate that fungal pretreatment can enhance the production of valuable aromatics and decrease the amount of undesired coke, and thus has a beneficial effect on biomass conversion in CFP. Copyright © 2013 Elsevier Ltd. All rights reserved.

Steam gasification of a thermally pretreated high lignin corn stover simultaneous saccharification and fermentation digester residue

Energy Technology Data Exchange (ETDEWEB)

Howe, Daniel T.; Taasevigen, Danny; Garcia-Perez, Manuel; McDonald, Armando G.; Li, Guosheng; Wolcott, Michael

2017-01-01

Efficient conversion of all components in lignocellulosic biomass is essential to realizing economic feasibility of biorefineries. However, when utilizing biochemical pathways, lignin cannot be fermented. Furthermore, the high lignin and high ash residue resulting from simultaneous saccharification and fermentation (SSF) reactors is difficult to thermochemically process due to feed line plugging and bed agglomeration. In this study a corn stover SSF digester residue was thermally pretreated at 300°C for 22.5 minutes (min) and then gasified in a bubbling fluidized bed gasifier to study the effect of thermal pretreatment on its processing behavior. Untreated, pelletized SSF residue was gasified at the same conditions to establish the baseline processing behavior. Results indicate that the thermal pretreatment process removes a substantial portion of the polar and non-polar extractives, with a resultant increase in the concentration of lignin, cellulose, and ash. Feed line plugging was not observed, although bed agglomeration was occurring at similar rates for both feedstocks, suggesting that overall ash content is the most important factor affecting bed agglomeration. Benzene, phenol, and polyaromatic hydrocarbons in the tar were present at higher concentrations in the treated material, with higher tar loading in the product gas. Total product gas generation is lower for the treated material, although the overall gas composition does not change.

Alkaline/peracetic acid as a pretreatment of lignocellulosic biomass for ethanol fuel production

Science.gov (United States)

Teixeira, Lincoln Cambraia

Peracetic acid is a lignin oxidation pretreatment with low energy input by which biomass can be treated in a silo type system for improving enzymatic digestibility of lignocellulosic materials for ethanol production. Experimentally, ground hybrid poplar wood and sugar cane bagasse are placed in plastic bags and a peracetic acid solution is added to the biomass in different concentrations based on oven-dry biomass. The ratio of solution to biomass is 6:1; after initial mixing of the resulting paste, a seven-day storage period at about 20°C is used in this study. As a complementary method, a series of pre-pretreatments using stoichiometric amounts of sodium hydroxide and ammonium hydroxide based on 4-methyl-glucuronic acid and acetyl content in the biomass is been performed before addition of peracetic acid. The alkaline solutions are added to the biomass in a ratio of 14:1 solution to biomass; the slurry is mixed for 24 hours at ambient temperature. The above procedures give high xylan content substrates. Consequently, xylanase/beta-glucosidase combinations are more effective than cellulase preparations in hydrolyzing these materials. The pretreatment effectiveness is evaluated using standard enzymatic hydrolysis and simultaneous saccharification and cofermentation (SSCF) procedures. Hybrid poplar wood pretreated with 15 and 21% peracetic acid based on oven-dry weight of wood gives glucan conversion yields of 76.5 and 98.3%, respectively. Sugar cane bagasse pretreated with the same loadings gives corresponding yields of 85.9 and 93.1%. Raw wood and raw bagasse give corresponding yields of 6.8 and 28.8%, respectively. The combined 6% NaOH/15% peracetic acid pretreatments increase the glucan conversion yields from 76.5 to 100.0% for hybrid poplar wood and from 85.9 to 97.6% for sugar cane bagasse. Respective ethanol yields of 92.8 and 91.9% are obtained from 6% NaOH/15% peracetic acid pretreated materials using recombinant Zymomonas mobilis CP4/pZB5. Peracetic acid

NREL 2012 Achievement of Ethanol Cost Targets: Biochemical Ethanol Fermentation via Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover

Energy Technology Data Exchange (ETDEWEB)

Tao, L.; Schell, D.; Davis, R.; Tan, E.; Elander, R.; Bratis, A.

2014-04-01

For the DOE Bioenergy Technologies Office, the annual State of Technology (SOT) assessment is an essential activity for quantifying the benefits of biochemical platform research. This assessment has historically allowed the impact of research progress achieved through targeted Bioenergy Technologies Office funding to be quantified in terms of economic improvements within the context of a fully integrated cellulosic ethanol production process. As such, progress toward the ultimate 2012 goal of demonstrating cost-competitive cellulosic ethanol technology can be tracked. With an assumed feedstock cost for corn stover of $58.50/ton this target has historically been set at $1.41/gal ethanol for conversion costs only (exclusive of feedstock) and $2.15/gal total production cost (inclusive of feedstock) or minimum ethanol selling price (MESP). This year, fully integrated cellulosic ethanol production data generated by National Renewable Energy Laboratory (NREL) researchers in their Integrated Biorefinery Research Facility (IBRF) successfully demonstrated performance commensurate with both the FY 2012 SOT MESP target of $2.15/gal (2007$, $58.50/ton feedstock cost) and the conversion target of $1.41/gal through core research and process improvements in pretreatment, enzymatic hydrolysis, and fermentation.

Comparative performance of precommercial cellulases hydrolyzing pretreated corn stover

Science.gov (United States)

2011-01-01

Background Cellulases and related hydrolytic enzymes represent a key cost factor for biochemical conversion of cellulosic biomass feedstocks to sugars for biofuels and chemicals production. The US Department of Energy (DOE) is cost sharing projects to decrease the cost of enzymes for biomass saccharification. The performance of benchmark cellulase preparations produced by Danisco, DSM, Novozymes and Verenium to convert pretreated corn stover (PCS) cellulose to glucose was evaluated under common experimental conditions and is reported here in a non-attributed manner. Results Two hydrolysis modes were examined, enzymatic hydrolysis (EH) of PCS whole slurry or washed PCS solids at pH 5 and 50°C, and simultaneous saccharification and fermentation (SSF) of washed PCS solids at pH 5 and 38°C. Enzymes were dosed on a total protein mass basis, with protein quantified using both the bicinchoninic acid (BCA) assay and the Bradford assay. Substantial differences were observed in absolute cellulose to glucose conversion performance levels under the conditions tested. Higher cellulose conversion yields were obtained using washed solids compared to whole slurry, and estimated enzyme protein dosages required to achieve a particular cellulose conversion to glucose yield were extremely dependent on the protein assay used. All four enzyme systems achieved glucose yields of 90% of theoretical or higher in SSF mode. Glucose yields were reduced in EH mode, with all enzymes achieving glucose yields of at least 85% of theoretical on washed PCS solids and 75% in PCS whole slurry. One of the enzyme systems ('enzyme B') exhibited the best overall performance. However in attaining high conversion yields at lower total enzyme protein loadings, the relative and rank ordered performance of the enzyme systems varied significantly depending upon which hydrolysis mode and protein assay were used as the basis for comparison. Conclusions This study provides extensive information about the

Comparative performance of precommercial cellulases hydrolyzing pretreated corn stover

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Mohagheghi Ali

2011-09-01

Full Text Available Abstract Background Cellulases and related hydrolytic enzymes represent a key cost factor for biochemical conversion of cellulosic biomass feedstocks to sugars for biofuels and chemicals production. The US Department of Energy (DOE is cost sharing projects to decrease the cost of enzymes for biomass saccharification. The performance of benchmark cellulase preparations produced by Danisco, DSM, Novozymes and Verenium to convert pretreated corn stover (PCS cellulose to glucose was evaluated under common experimental conditions and is reported here in a non-attributed manner. Results Two hydrolysis modes were examined, enzymatic hydrolysis (EH of PCS whole slurry or washed PCS solids at pH 5 and 50°C, and simultaneous saccharification and fermentation (SSF of washed PCS solids at pH 5 and 38°C. Enzymes were dosed on a total protein mass basis, with protein quantified using both the bicinchoninic acid (BCA assay and the Bradford assay. Substantial differences were observed in absolute cellulose to glucose conversion performance levels under the conditions tested. Higher cellulose conversion yields were obtained using washed solids compared to whole slurry, and estimated enzyme protein dosages required to achieve a particular cellulose conversion to glucose yield were extremely dependent on the protein assay used. All four enzyme systems achieved glucose yields of 90% of theoretical or higher in SSF mode. Glucose yields were reduced in EH mode, with all enzymes achieving glucose yields of at least 85% of theoretical on washed PCS solids and 75% in PCS whole slurry. One of the enzyme systems ('enzyme B' exhibited the best overall performance. However in attaining high conversion yields at lower total enzyme protein loadings, the relative and rank ordered performance of the enzyme systems varied significantly depending upon which hydrolysis mode and protein assay were used as the basis for comparison. Conclusions This study provides extensive

Dilute oxalic acid pretreatment for biorefining giant reed (Arundo donax L.)

Science.gov (United States)

Danilo Scordia; Salvatore L. Cosentino; Jae-Won Lee; Thomas W. Jeffries

2011-01-01

Biomass pretreatment is essential to overcome recalcitrance of lignocellulose for ethanol production. In the present study we pretreated giant reed (Arundo donax L.), a perennial, rhizomatous lignocellulosic grass with dilute oxalic acid. The effects of temperature (170-190 ºC), acid loading (2-10% w/w) and reaction time (15-40 min) were handled as a single...

Microwave-assisted acid pretreatment of alkali lignin: Effect on characteristics and pyrolysis behavior.

Science.gov (United States)

Duan, Dengle; Ruan, Roger; Wang, Yunpu; Liu, Yuhuan; Dai, Leilei; Zhao, Yunfeng; Zhou, Yue; Wu, Qiuhao

2018-03-01

This study performed microwave-assisted acid pretreatment on pure lignin. The effects of microwave temperature, microwave time, and hydrochloric acid concentration on characteristics and pyrolysis behavior of lignin were examined. Results of ultimate analysis revealed better properties of all pretreated samples than those of raw lignin. Fourier transform infrared spectroscopy analysis showed breakage of βO4 bond and aliphatic side chain, decrease in OH groups, and formation of CO groups in pretreatment. Microwave temperature exerted more significant influence on lignin structure. Thermal stability of treated lignin was improved and insensitive to short microwave time and acid concentration under mild conditions. Resulting from improved alkyl-phenols and decreased alkoxy-phenols, microwave-assisted acid pretreatment of lignin yielded bio-oil with excellent quality. Total yield of phenols in pyrolysis vapors (200 °C) improved to 14.15%, whereas that of guaiacols decreased to 22.36%. This study shows that microwave-assisted acid pretreatment is a promising technology for lignin conversion. Copyright © 2017 Elsevier Ltd. All rights reserved.

High-Yield Production of Levulinic Acid from Pretreated Cow Dung in Dilute Acid Aqueous Solution

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Jialei Su

2017-02-01

Full Text Available Agricultural waste cow dung was used as feedstock for the production of a high value–added chemical levulinic acid (LA in dilute acid aqueous solutions. A high LA yield of 338.9 g/kg was obtained from the pretreated cow dung, which was much higher than that obtained from the crude cow dung (135 g/kg, mainly attributed to the breakage of the lignin fraction in the lignocellulose structure of the cow dung by potassium hydroxide (KOH pretreatment, and thus enhanced the accessibility of cow dung to the acid sites in the catalytic reaction. Meanwhile, another value-added chemical formic acid could be obtained with a yield of ca. 160 g/kg in the process, implying a total production of ca. 500 g/kg yield for LA and formic acid from the pretreated cow dung with the proposed process. The developed process was shown to be tolerant to high initial substrate loading with a satisfied LA yield. This work provides a promising strategy for the value-increment utilization of liglocellulosic agricultural residues.

One-step pretreatment of yellow poplar biomass using peracetic acid to enhance enzymatic digestibility.

Science.gov (United States)

Lee, Hyeong Rae; Kazlauskas, Romas J; Park, Tai Hyun

2017-09-22

Pretreatment of biomass with dilute acid requires high temperatures of >160 °C to remove xylan and does not remove lignin. Here we report that the addition of peracetic acid, a strong oxidant, to mild dilute acid pretreatment reduces the temperature requirement to only 120 °C. Pretreatment of yellow poplar with peracetic acid (300 mM, 2.3 wt%) and dilute sulfuric acid (100 mM, 1.0 wt%) at 120 °C for 5 min removed 85.7% of the xylan and 90.4% of the lignin leaving a solid consisting of 75.6% glucan, 6.0% xylan and 4.7% lignin. Low enzyme loadings of 5 FPU/g glucan and 10 pNPGU/g glucan converted this solid to glucose with an 84.0% yield. This amount of glucose was 2.5 times higher than with dilute acid-pretreated solid and 13.8 times higher than with untreated yellow poplar. Thus, the addition of peracetic acid, easily generated from acetic acid and hydrogen peroxide, dramatically increases the effectiveness of dilute acid pretreatment of biomass.

Biomass Deconstruction and Pretreatment Publications | Bioenergy | NREL

Science.gov (United States)

Analysis, ACS Sustainable Chemistry & Engineering Eight black-and-white micrograph images of corn Hydrocarbons via Aqueous Phase Hydrodeoxygenation, Green Chemistry Image of a diagram with a curved line Chemistry & Engineering Image of a diagram corn stover pretreatment showing arrows pointing from "

THERMO-MECHANICAL PULPING AS A PRETREATMENT FOR AGRICULTURAL BIOMASS FOR BIOCHEMICAL CONVERSION

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Ronalds W. Gonzalez

2011-03-01

Full Text Available The use of thermo-mechanical pulping (TMP, an existing and well known technology in the pulp and paper industry, is proposed as a potential pretreatment pathway of agriculture biomass for monomeric sugar production in preparation for further fermentation into alcohol species. Three agricultural biomass types, corn stover, wheat straw, and sweet sorghum bagasse, were pretreated in a TMP unit under two temperature conditions, 160 ºC and 170 ºC, and hydrolyzed using cellulase at 5, 10, and 20 FPU/g OD biomass. Wheat straw biomass was further pretreated at different conditions including: i soaking with acetic acid, ii longer steaming residence time (15 and 30 min, and iii refined at lower disk gap (0.0508 and 0.1524 mm. Preliminary results showed that carbohydrate conversion increased from 25% to 40% when the TMP temperature was increased from 160 to 170 ºC. Carbohydrate conversion was relatively similar for the three biomasses under the same pretreatment conditions and enzyme loading. Acetic acid soaking and refining at a reduce disk gap increases carbohydrate conversion. Further studies within this technological field to identify optimum process and TMP conditions for pretreatment are suggested.

Optimisation of dilute acid pre-treatment of artisan rice hulls for ethanol production

International Nuclear Information System (INIS)

Lopez, Yoney; Martin, Carlos; Gullon, Beatriz; Parajo, Juan Carlos

2011-01-01

Rice hulls are potential low-cost feedstocks for fuel ethanol production in many countries. In this work, the dilute-acid pre-treatment of artisan rice hulls was investigated using a central composite rotatable experimental design. The experimental variables were temperature (140-210 C), biomass load (5-20%) and sulphuric acid concentration (0.5-1.5 g per 100 g of reaction mixture). A total of 16 experimental runs, including a 23-plan, two replicates at the central point and six star points, were carried out. Low temperatures were found to be favourable for the hydrolysis of xylan and of the easily hydrolyzable glucan fraction. High glucose formation (up to 15.3 g/100 g), attributable to starch hydrolysis, was detected in the hydrolysates obtained under the least severe pre-treatment conditions. Using the experimental results, several models for predicting the effect of the operational conditions on the yield of pretreated solids, xylan and glucan conversion upon pre-treatment, and on enzymatic convertibility of cellulose were developed. Optimum results were predicted for the conversion of easily-hydrolyzable glucan in the material pretreated at 140.7 C, and for the enzymatic saccharification of cellulose in the material pretreated at 169 C. These results suggested the use of two-step acid hydrolysis as future pre-treatment strategy for artisan rice hulls. Key words: Dilute acid hydrolysis, enzymatic hydrolysis, pre-treatment, rice hulls. (author)

Pretreatment of macroalgae for volatile fatty acid production.

Science.gov (United States)

Pham, Thi Nhan; Um, Youngsoon; Yoon, Hyon Hee

2013-10-01

In this study, a novel method was proposed for the biological pretreatment of macroalgae (Laminaria japonica, Pachymeniopsis elliptica, and Enteromorpha crinita) for production of volatile fatty acid (VFA) by anaerobic fermentation. The amount of VFA produced from 40 g/L of L. japonica increased from 8.3 g/L (control) to 15.6 g/L when it was biologically pretreated with Vibrio harveyi. The biological treatment of L. japonica with Vibrio spp. was most effective likely due to the alginate lyase activity of Vibrio spp. However, a considerable effect was also observed after biological pretreatment of P. elliptica and E. crinita, which are red and green algae, respectively. Alkaline pretreatment of 40 g/L of L. japonica with 0.5 N NaOH resulted in an increase of VFA production to 12.2 g/L. These results indicate that VFA production from macroalgae can be significantly enhanced using the proposed biological pretreatments. Copyright © 2013 Elsevier Ltd. All rights reserved.

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.)

DEFF Research Database (Denmark)

Gunnarsson, Ingólfur Bragi; Kuglarz, Mariusz; Karakashev, Dimitar Borisov

2015-01-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior...... to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted...... in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9gL-1), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid....

Pretreatment of dried distillers grains with solubles by soaking in aqueous ammonia and subsequent enzymatic/dilute acid hydrolysis to produce fermentable sugars

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Dried distillers grains with solubles (DDGS), a co-product of corn ethanol production in the dry-grind process, was pretreated by soaking in aqueous ammonia (SAA) using a 15% w/w NH4OH solution at a solid:liquid ratio of 1:10. The effect of pretreatment on subsequent enzymatic hydrolysis was studied...

Physicochemical pretreatments and hydrolysis of furfural residues via carbon-based sulfonated solid acid.

Science.gov (United States)

Ma, Bao Jun; Sun, Yuan; Lin, Ke Ying; Li, Bing; Liu, Wan Yi

2014-03-01

Potential commercial physicochemical pretreatment methods, NaOH/microwave and NaOH/ultrasound were developed, and the carbon-based sulfonated solid acid catalysts were prepared for furfural residues conversion into reducing sugars. After the two optimum pretreatments, both the content of cellulose increased (74.03%, 72.28%, respectively) and the content of hemicellulose (94.11%, 94.17% of removal rate, respectively) and lignin (91.75%, 92.09% of removal rate, respectively) decreased in furfural residues. The reducing sugar yields of furfural residues with the two physicochemical pretreatments on coal tar-based solid acid reached 33.94% and 33.13%, respectively, higher than that pretreated via NaOH alone (27%) and comparable to that pretreated via NaOH/H2O2 (35.67%). The XRD patterns, IR spectra and SEM images show microwave and ultrasound improve the pretreatment effect. The results demonstrate the carbon-based sulfonated solid acids and the physicochemical pretreatments are green, effective, low-cost for furfural residues conversion. Copyright © 2014 Elsevier Ltd. All rights reserved.

Rumen volatile fatty acids and milk composition from cows fed hay, haylage, or urea-treated corn silage.

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Schingoethe, D J; Voelker, H H; Beardsley, G L; Parsons, J G

1976-05-01

Alfalfa-brome hay, haylage, .5% urea-treated corn silage, or .5% urea plus 1% dried whey-treated corn silage was fed as the only forage to one of four groups of 10 lactating cows per group for a lactation trial of 10 wk. Rumen samples were collected via stomach tube 3 to 4 h after the morning feeding. The pH of the rumen samples from cows fed hay was higher than for cows fed haylage, urea-treated corn silage, and urea-whey corn silage, 6.69 versus 6.36, 6.40, and 6.50. Total volatile fatty acids and propionate were highest from cows fed urea-whey corn silage and were higher on all three fermented forages than cows fed hay. Acetate/propionate ratio was highest from cows fed hay and lowest from cows fed corn silages. Butyrate was highest from cows fed haylage or hay. Milk protein composition was not affected by ration although nonprotein nitrogen of milk was highest from cows fed the urea-treated corn silages. Oleic acid and total unsaturated fatty acids were lowest in milk fat from cows fed hay while palmitic acid was highest from cows fed hay and haylage. These results suggest that type of forage fed may cause small changes in rumen fermentation and in milk composition. The importance of these changes is unknown but may affect properties of dairy products produced from this milk.

Effects of corn oil on the volatile fatty acids in horses with induced gastric ulcers

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José Martínez A

2016-09-01

Full Text Available Objetive. To determine the influence of corn oil on the volatile fatty acids (VFA concentrations in the gastric juice in horses with phenylbutazone (PBZ induced gastric ulcers and Correlate the gastroscopic findings with the VFA concentrations. Materials and methods. 15 horses were allotted in 3 groups. Group I (control received placebo during first 6 days (induction period and was treated with sucralfate for 2 weeks (treatment period. Groups II and III received PBZ during the induction phase. After 6 days, horses from group II received 70 mL of corn oil /100 kg of body weight/ po, twice a day, for 2 weeks and horses from group III received 90 mL of corn oil/100 kg of body weight/ po, twice a day, for 2 weeks. All horses were examined by gastroscopy at days 0, 7 and 21. The lesions were recorded and classified according to the number and severity. Samples from gastric fluid were taken to measure the concentrations of the acetic, propionic, butyric and lactic acids. Results. Both PBZ protocols produced lesions in the both non-glandular and glandular areas of the stomach. All the treatments produced healing of the injured mucosa glandular. Neither of the two corn oil treatments affected healing of the gastric ulcers located in the non-glandular area. Conclusions. The concentrations of acetic and butyric acids were highest in the gastric juice. The corn oil and sucralfate did not lead to differences in the concentration of acetic acid and butyric acid.

Production of xylitol from corn cob hydrolysate through acid and enzymatic hydrolysis by yeast

Science.gov (United States)

Mardawati, Efri; Andoyo, R.; Syukra, K. A.; Kresnowati, MTAP; Bindar, Y.

2018-03-01

The abundance of corn production in Indonesia offers the potential for its application as the raw material for biorefinery process. The hemicellulose content in corn cobs can be considered to be used as a raw material for xylitol production. The purpose of this research was to study the effect of hydrolysis methods for xylitol production and the effect of the hydrolyzed corn cobs to produce xylitol through fermentation. Hydrolysis methods that would be evaluated were acid and enzymatic hydrolysis. The result showed that the xylitol yield of fermented solution using enzymatic hydrolysates was 0.216 g-xylitol/g-xylose, which was higher than the one that used acid hydrolysates, which was 0.100 g-xylitol/g-xylose. Moreover, the specific growth rate of biomass in fermentation using enzymatic hydrolysates was also higher than the one that used acid hydrolysates, 0.039/h compared to 0.0056/h.

Compounds formed by treatment of corn (Zea mays) with nitrous acid.

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Archer, M C; Hansen, T J; Tannenbaum, S R

1980-01-01

Nitrohexane has been identified as a major product formed following treatment of corn (Zea mays) with nitrous acid. Preliminary evidence suggests that another compound isolated from the nitrosated corn is an unsaturated nitrolic acid. As an aid to the analysis of N-nitro compounds, we have characterized the response of a chemiluminescence detector (Thermal Energy Analyzer) as a function of pyrolysis chamber temperature for several nitrosamines and for an aliphatic C-nitroso compound, an aromatic C-nitro compound, a nitramine and an alkyl nitrite. The response-temperature profiles are valuable in distinguishing among the various compounds and in optimizing the sensitivity of the detector for use in chromatography. Other tests, including photolysis and stability toward nitrite-scavenging reagents, further aid in distinguishing among the various compounds.

Fortification of Corn Masa Flour With Folic Acid in the United States

Science.gov (United States)

Oinuma, Motoko

2011-01-01

Food fortification is an effective public health tool for addressing micronutrient deficiencies. The mandatory fortification of enriched cereal grains (e.g., wheat flour) with folic acid, which began in the United States in 1998, is an example of a successful intervention that significantly reduced the rate of neural tube defects (NTDs). However, despite the drop in NTD rates across all racial/ethnic groups after fortification, Hispanics continue to have the highest rates of this condition. One possible way to reduce this disparity is to fortify corn masa flour to increase the overall intake of folic acid in Hispanic women. We present the available evidence in favor of this approach, address possible safety issues, and outline next steps in the fortification of corn masa flour with folic acid in the United States. PMID:21680940

Thermochemical pretreatments for enhancing succinic acid production from industrial hemp (Cannabis sativa L.).

Science.gov (United States)

Gunnarsson, Ingólfur B; Kuglarz, Mariusz; Karakashev, Dimitar; Angelidaki, Irini

2015-04-01

The aim of this study was to develop an efficient thermochemical method for treatment of industrial hemp biomass, in order to increase its bioconversion to succinic acid. Industrial hemp was subjected to various thermochemical pretreatments using 0-3% H2SO4, NaOH or H2O2 at 121-180°C prior to enzymatic hydrolysis. The influence of the different pretreatments on hydrolysis and succinic acid production by Actinobacillus succinogenes 130Z was investigated in batch mode, using anaerobic bottles and bioreactors. Enzymatic hydrolysis and fermentation of hemp material pretreated with 3% H2O2 resulted in the highest overall sugar yield (73.5%), maximum succinic acid titer (21.9 g L(-1)), as well as the highest succinic acid yield (83%). Results obtained clearly demonstrated the impact of different pretreatments on the bioconversion efficiency of industrial hemp into succinic acid. Copyright © 2015. Published by Elsevier Ltd.

APLIKASI THERMAL PRE-TREATMENT LIMBAH TANAMAN JAGUNG (Zea mays SEBAGAI CO·SUBSTRAT PADA PROSES ANAEROBIK DIGESTI UNTUK PRODUKSI BIOGAS

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Darwin Darwin

2016-04-01

Full Text Available Thermal pre-treatment was given on corn stover in the purpose of breaking the lignin content; thus, it may help anaerobic microorganisms to convert polymer including cellulose and hemicelluloses into biogas. This study aimed to investigate the effects of thermal pre-treatment on corn stover in anaerobic digestion process related to the production of biogas as well as digestion process efficiency. This research was carried out by utilizing batch reactors where the temperature was maintained at mesophilic conditions above room temperature (33 ± 2 oC. Based on the result, it was known that thermal pre-treatment given on the corn stover may enhance anaerobic digestion process for biogas production at the first 10 days. This condition reduced the time of lag phase during anaerobic digestion. The biogas production of corn stover given thermal pre-treatment was slow at 26 days where their average total production were 12,412.5 mL,12,310 mL at 15 and 25 minutes thermal pre-treatment, respectively while biogas production of non pre-treated corn stover was 12,557 mL. The highest daily biogas production was accomplished by corn stover that was given thermal pre-treatment at 25 minutes (915 mL. Corn stover given with 15 minutes thermal pre-treatment also generated higher daily biogas production at day 9 (772.5 mL compared with corn stover that was not pre-treated (405 mL. This research also revealed that corn stover given thermal pre-treatment reached higher biogas yield compared with non pre-treated corn stover where their biogas yield were 670.39, 690.65 mL/g volatile solids added at 15 and 25 minutes thermal pre- treatment respectively, and 456.37 mL/g volatile solids added of non pre-treated corn stover. Keywords: Thermal pre-treatment, corn stover, anaerobic digestion, biogas   ABSTRAK Thermal pre-treatment diberikan pada limbah tanaman jagung dengan tujuan untuk memecahkan kandungan lignin yang terdapat pada limbah tanaman jagung sehingga memudahkan

Physicochemical Properties of Gelatin Extracted from Buffalo Hide Pretreated with Different Acids.

Science.gov (United States)

Mulyani, Sri; Setyabudi, Francis M C Sigit; Pranoto, Yudi; Santoso, Umar

2017-01-01

The acid pretreatment of collagen molecules disrupts their crosslinks and assists in the release of acid-soluble proteins, fats, and other components. Generally, to achieve optimum extraction efficiency, strong acids may be used at a lower acid concentration compared to weak acids. This study aimed to determine the yield and physicochemical properties of gelatins extracted from buffalo hides pretreated with different acids. Hides were extracted with hydrochloric, citric, and acetic acids at concentrations of 0.3, 0.6, 0.9, 1.2, and 1.5 M. A completely randomized design and the least significant difference test were used in the experimental design, and all measurements were performed in triplicate. The highest yield (29.17%) was obtained from pretreatment with 0.9 M HCl. The gel strength did not differ significantly ( p >0.05) according to acid type (280.26-259.62 g Bloom), and the highest viscosity was obtained from the 0.6 M citric acid pretreatment. All the gelatins contained α- and β-chain components and several degraded peptides (24-66 kDa). The color and Fourier-transform infrared spectrum of the gelatin extracted using 0.9 M HCl were similar to those of commercial bovine skin gelatin. In general, the physicochemical properties of the gelatin complied with the industry standard set by the Gelatin Manufacturers Institute of America, revealing that buffalo hide could serve as a potential alternative source of gelatin.

Initial performance of corn in response to treatment of seeds with humic acids isolated from bokashi

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Marihus Altoé Baldotto

2016-02-01

Full Text Available ABSTRACT The humified organic matter presents bioactivity similar to the auxinic effect. As bokashi is produced by a special process of humification, information is needed about the bioactive potential of its humic acids. The objective of this work was studying the initial performance of corn-indicator plants in response to the application of different concentrations of humic acids isolated from bokashi. The corn seeds were treated for 16 hours with solutions containing 0, 10, 20, 30, 40 and 80 mmol L-1 of C in the form of humic acids. Then, the seeds were planted in pots of 1 dm3 containing corrected and fertilized soil, in greenhouse. Growth characteristics of shoot and root systems were evaluated. The results showed that the humic acids extracted from bokashi had positive effects on the initial performance of corn.

Site and extent of amino acid digestion in dairy cattle fed with corn and its byproducts

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Reginaldo Nassar Ferreira

2015-02-01

Full Text Available The study was conducted to evaluated the site and extent of dry matter (DM, crude protein (CP, methionine (Met, lysine (Lys, and threonine (Thr digestion of corn and byproducts obtained from corn germ mixed with different amounts of extruded or non-extruded ether extract (EE in dairy cattle. Treatments consisted in eight types of feed and two processing in a 4 × 2 factorial design. There were four feeds: corn grain cracked (Corn, corn germ meal with 1% EE (CG1, corn germ meal with 7% EE (CG7, and corn germ meal with 10% EE (CG10. The feeds were processed in one of two ways: extruded (Ex and not extruded. In situ techniques were used to determine DM, CP, Met, Lys, and Thr partial and total tract digestion. A basic diet was compounded of corn germ meal, soybean meal and coastcross hay in a 70:30 roughage to concentrate ratio. There was no interaction (P>0.05 between feeds and processing method. Extrusion improved (P0.05 for corn and corn germ meal mixed with 7 and 10% EE, regardless of EE processing method. The CP total tract digestibility of corn germ meal with 1% nonextruded EE was 16.62% higher (P<0.05 than that of the extruded form. The best total CP digestibility was obtained for corn germ meal with 7% EE, independently of the processing method. The effects of EE processing method on partial and total digestibility differed between amino acid. Corn and corn byproduct extrusion may improve dry matter digestibility, but do not necessarily influence crude protein digestion. Ruminal and intestinal digestibility of Met, Lys, and Thr depends on both feed type and processing method. Therefore, amino acid availability should be considered individually.

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

Science.gov (United States)

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

2009-05-01

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

Rapid optimization of enzyme mixtures for deconstruction of diverse pretreatment/biomass feedstock combinations

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Walton Jonathan D

2010-10-01

Full Text Available Abstract Background Enzymes for plant cell wall deconstruction are a major cost in the production of ethanol from lignocellulosic biomass. The goal of this research was to develop optimized synthetic mixtures of enzymes for multiple pretreatment/substrate combinations using our high-throughput biomass digestion platform, GENPLAT, which combines robotic liquid handling, statistical experimental design and automated Glc and Xyl assays. Proportions of six core fungal enzymes (CBH1, CBH2, EG1, β-glucosidase, a GH10 endo-β1,4-xylanase, and β-xylosidase were optimized at a fixed enzyme loading of 15 mg/g glucan for release of Glc and Xyl from all combinations of five biomass feedstocks (corn stover, switchgrass, Miscanthus, dried distillers' grains plus solubles [DDGS] and poplar subjected to three alkaline pretreatments (AFEX, dilute base [0.25% NaOH] and alkaline peroxide [AP]. A 16-component mixture comprising the core set plus 10 accessory enzymes was optimized for three pretreatment/substrate combinations. Results were compared to the performance of two commercial enzymes (Accellerase 1000 and Spezyme CP at the same protein loadings. Results When analyzed with GENPLAT, corn stover gave the highest yields of Glc with commercial enzymes and with the core set with all pretreatments, whereas corn stover, switchgrass and Miscanthus gave comparable Xyl yields. With commercial enzymes and with the core set, yields of Glc and Xyl were highest for grass stovers pretreated by AP compared to AFEX or dilute base. Corn stover, switchgrass and DDGS pretreated with AFEX and digested with the core set required a higher proportion of endo-β1,4-xylanase (EX3 and a lower proportion of endo-β1,4-glucanase (EG1 compared to the same materials pretreated with dilute base or AP. An optimized enzyme mixture containing 16 components (by addition of α-glucuronidase, a GH11 endoxylanase [EX2], Cel5A, Cel61A, Cip1, Cip2, β-mannanase, amyloglucosidase, �

Mild-temperature dilute acid pretreatment for integration of first and second generation ethanol processes.

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Nair, Ramkumar B; Kalif, Mahdi; Ferreira, Jorge A; Taherzadeh, Mohammad J; Lennartsson, Patrik R

2017-12-01

The use of hot-water (100°C) from the 1st generation ethanol plants for mild-temperature lignocellulose pretreatment can possibly cut down the operational (energy) cost of 2nd generation ethanol process, in an integrated model. Dilute-sulfuric and -phosphoric acid pretreatment at 100°C was carried out for wheat bran and whole-stillage fibers. Pretreatment time and acid type influenced the release of sugars from wheat bran, while acid-concentration was found significant for whole-stillage fibers. Pretreatment led up-to 300% improvement in the glucose yield compared to only-enzymatically treated substrates. The pretreated substrates were 191-344% and 115-300% richer in lignin and glucan, respectively. Fermentation using Neurospora intermedia, showed 81% and 91% ethanol yields from wheat bran and stillage-fibers, respectively. Sawdust proved to be a highly recalcitrant substrate for mild-temperature pretreatment with only 22% glucose yield. Both wheat bran and whole-stillage are potential substrates for pretreatment using waste heat from the 1st generation process for 2nd generation ethanol. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of dilute alkaline pretreatment on the conversion of different parts of corn stalk to fermentable sugars and its application in acetone-butanol-ethanol fermentation.

Science.gov (United States)

Cai, Di; Li, Ping; Luo, Zhangfeng; Qin, Peiyong; Chen, Changjing; Wang, Yong; Wang, Zheng; Tan, Tianwei

2016-07-01

To investigate the effect of dilute alkaline pretreatment on different parts of biomass, corn stalk was separated into flower, leaf, cob, husk and stem, which were treated by NaOH in range of temperature and chemical loading. The NaOH-pretreated solid was then enzymatic hydrolysis and used as the substrate for batch acetone-butanol-ethanol (ABE) fermentation. The results demonstrated the five parts of corn stalk could be used as potential feedstock separately, with vivid performances in solvents production. Under the optimized conditions towards high product titer, 7.5g/L, 7.6g/L, 9.4g/L, 7g/L and 7.6g/L of butanol was obtained in the fermentation broth of flower, leaf, cob, husk and stem hydrolysate, respectively. Under the optimized conditions towards high product yield, 143.7g/kg, 126.3g/kg, 169.1g/kg, 107.7g/kg and 116.4g/kg of ABE solvent were generated, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

Detoxification of Corncob Acid Hydrolysate with SAA Pretreatment and Xylitol Production by Immobilized Candida tropicalis

Science.gov (United States)

Deng, Li-Hong; Tang, Yong; Liu, Yun

2014-01-01

Xylitol fermentation production from corncob acid hydrolysate has become an attractive and promising process. However, corncob acid hydrolysate cannot be directly used as fermentation substrate owing to various inhibitors. In this work, soaking in aqueous ammonia (SAA) pretreatment was employed to reduce the inhibitors in acid hydrolysate. After detoxification, the corncob acid hydrolysate was fermented by immobilized Candida tropicalis cell to produce xylitol. Results revealed that SAA pretreatment showed high delignification and efficient removal of acetyl group compounds without effect on cellulose and xylan content. Acetic acid was completely removed, and the content of phenolic compounds was reduced by 80%. Furthermore, kinetic behaviors of xylitol production by immobilized C. tropicalis cell were elucidated from corncob acid hydrolysate detoxified with SAA pretreatment and two-step adsorption method, respectively. The immobilized C. tropicalis cell showed higher productivity efficiency using the corncob acid hydrolysate as fermentation substrate after detoxification with SAA pretreatment than by two-step adsorption method in the five successive batch fermentation rounds. After the fifth round fermentation, about 60 g xylitol/L fermentation substrate was obtained for SAA pretreatment detoxification, while about 30 g xylitol/L fermentation substrate was obtained for two-step adsorption detoxification. PMID:25133211

Efficient sugar release by acetic acid ethanol-based organosolv pretreatment and enzymatic saccharification.

Science.gov (United States)

Zhang, Hongdan; Wu, Shubin

2014-12-03

Acetic acid ethanol-based organosolv pretreatment of sugar cane bagasse was performed to enhance enzymatic hydrolysis. The effect of different parameters (including temperature, reaction time, solvent concentration, and acid catalyst dose) on pretreatment prehydrolyzate and subsequent enzymatic digestibility was determined. During the pretreatment process, 11.83 g of xylose based on 100 g of raw material could be obtained. After the ethanol-based pretreatment, the enzymatic hydrolysis was enhanced and the highest glucose yield of 40.99 g based on 100 g of raw material could be obtained, representing 93.8% of glucose in sugar cane bagasse. The maximum total sugar yields occurred at 190 °C, 45 min, 60:40 ethanol/water, and 5% dosage of acetic acid, reaching 58.36 g (including 17.69 g of xylose and 40.67 g of glucose) based on 100 g of raw material, representing 85.4% of total sugars in raw material. Furthermore, characterization of the pretreated sugar cane bagasse using X-ray diffraction and scanning electron microscopy analyses were also developed. The results suggested that ethanol-based organosolv pretreatment could enhance enzymatic digestibilities because of the delignification and removal of xylan.

Fast pyrolysis product distribution of biopretreated corn stalk by methanogen.

Science.gov (United States)

Wang, Tipeng; Ye, Xiaoning; Yin, Jun; Jin, Zaixing; Lu, Qiang; Zheng, Zongming; Dong, Changqing

2014-10-01

After pretreated by methanogen for 5, 15 and 25 days, corn stalk (CS) were pyrolyzed at 250, 300, 350, 400, 450 and 500 °C by Py-GC/MS and product distribution in bio-oil was analyzed. Results indicated that methanogen pretreatment changed considerably the product distribution: the contents of sugar and phenols increased; the contents of linear carbonyls and furans decreased; the contents of linear ketones and linear acids changed slightly. Methanogen pretreatment improved significantly the pyrolysis selectivity of CS to phenols especially 4-VP. At 250 °C, the phenols content increased from 42.25% for untreated CS to 79.32% for biopretreated CS for 5 days; the 4-VP content increased from 28.6% to 60.9%. Increasing temperature was contributed to convert more lignin into 4-VP, but decreased its content in bio-oil due to more other chemicals formed. The effects of biopretreatment time on the chemicals contents were insignificant. Copyright © 2014 Elsevier Ltd. All rights reserved.

Improving bioavailability of fruit wastes using organic acid: An exploratory study of biomass pretreatment for fermentation

International Nuclear Information System (INIS)

Saha, Shouvik; Kurade, Mayur B.; El-Dalatony, Marwa M.; Chatterjee, Pradip K.; Lee, Dae Sung; Jeon, Byong-Hun

2016-01-01

Highlights: • Maximum sugar recovery was achieved with 100 °C/1 h treatment in 0.2 M acetic acid. • C/N ratios (41–47) were retained in all FPWs after the acetic acid treatment. • Combined severity (−0.83) of acetic acid enhanced the bioavailability of the FPWs. • Acetic acid pretreatment is advantageous over mineral acid to curtail sugar loss. • Estimated methane yields are promising for the industrial feasibility. - Abstract: Maximizing the bioavailability of fermentable biomass components is a key challenge in biomass pretreatment due to the loss of sugars during conventional pretreatment approaches. Pretreatment of fruit peels and wastes (FPWs) with dilute acetic acid assisted in maximizing sugar recovery. Optimized conditions (0.2 M acetic acid, 100 °C, 1 h) at 10% substrate loading resulted in enhanced sugar recovery from banana peels (99.9%), pineapple wastes (99.1%), grape pomace (98.8%), and orange peels (97.9%). These high sugar recoveries retained the high C/N ratios (41–47) suitable for effective bioenergy production through the fermentation of these pretreated biomasses. Scanning electron microscopy (SEM) indicated considerable disruption of biomass structural integrity during acetic acid treatment, enhancing the surface area available for better microbial attachment. Fourier transform infrared spectroscopy (FTIR) showed that the acetic acid pretreatment yielded only minor changes to the functional groups in the biomasses, strongly suggesting minimal loss of fermentable sugars. Thus, acetic acid pretreatment aids in enhancing the bioavailability of fermentable sugars from these FPWs biomass, enabling improvements in bioenergy production.

Kinetic Modelling and Experimental Studies for the Effects of Fe2+ Ions on Xylan Hydrolysis with Dilute-Acid Pretreatment and Subsequent Enzymatic Hydrolysis

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Hui Wei

2018-01-01

Full Text Available High-temperature (150–170 °C pretreatment of lignocellulosic biomass with mineral acids is well established for xylan breakdown. Fe2+ is known to be a cocatalyst of this process although kinetics of its action remains unknown. The present work addresses the effect of ferrous ion concentration on sugar yield and degradation product formation from corn stover for the entire two-step treatment, including the subsequent enzymatic cellulose hydrolysis. The feedstock was impregnated with 0.5% acid and 0.75 mM iron cocatalyst, which was found to be optimal in preliminary experiments. The detailed kinetic data of acid pretreatment, with and without iron, was satisfactorily modelled with a four-step linear sequence of first-order irreversible reactions accounting for the formation of xylooligomers, xylose and furfural as intermediates to provide the values of Arrhenius activation energy. Based on this kinetic modelling, Fe2+ turned out to accelerate all four reactions, with a significant alteration of the last two steps, that is, xylose degradation. Consistent with this model, the greatest xylan conversion occurred at the highest severity tested under 170 °C/30 min with 0.75 mM Fe2+, with a total of 8% xylan remaining in the pretreated solids, whereas the operational conditions leading to the highest xylose monomer yield, 63%, were milder, 150 °C with 0.75 mM Fe2+ for 20 min. Furthermore, the subsequent enzymatic hydrolysis with the prior addition of 0.75 mM of iron(II increased the glucose production to 56.3% from 46.3% in the control (iron-free acid. The detailed analysis indicated that conducting the process at lower temperatures yet long residence times benefits the yield of sugars. The above kinetic modelling results of Fe2+ accelerating all four reactions are in line with our previous mechanistic research showing that the pretreatment likely targets multiple chemistries in plant cell wall polymer networks, including those represented by the C�

DEVELOPMENT OF ACID-SOIL TOLERANT CORN (Zea mays L. WITH HIGH-QUALITY PROTEIN

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E.S. Halimi

2011-06-01

Full Text Available Corn is an important food crop in Indonesia. Plant expansion has been hampered by soil-acidity problem and the protein content of many corn varieties was low. This research initiates development of soil-acid-tolerant corn with high-quality-protein content. Research was done on 12 factorial treatments and 3 replications as blocks in RCBD. The first factor was corn populations: Toray-1(G1, Toray-2(G2, GS-5(G3 and GS-10(G4. The second factor was fertilizations: P1(69 kg N+36 kg P2O5+15 kg K2O per ha; P2(115 kg N+54 kg P2O5+30 kg K2O per ha; and P3(161 kg N+72 kg P2O5+45 kg K2O per ha. The observed variables consisted of several agronomic traits, including the protein content. Results indicated that the corn populations, in general, showed good agronomic traits. The differences were mostly between populations, not between fertilizations, and no interaction was observed. The yield potential ranged from 4.25 to 6.47 ton dry seeds per ha. The protein content of seed resulted from cross ranged from 9.84% to 11.30%, as compared to the parents of 9.11% and 12.62%. This research concludes that genetic factors play an important role as confirmed by heritability estimate (h2=0.75.

In vitro digestion and physicochemical characteristics of corn starch mixed with amino acid modified by low pressure treatment.

Science.gov (United States)

Ji, Ying

2018-03-01

The digestibility and molecular structure of corn starch mixed with amino acid modified by low-pressure treatment (LPT) was investigated. Amino acid induced a significant increase in the slowly digestible starch (SDS) and decrease in the rapidly digestible starch (RDS) after LPT. The reason is the formation of ester bond between the molecular chains of amino acid and starch. Low pressure treatment altered greatly the morphology of corn starch mixed with or without amino acid. After LPT, less ordered Maltese and more granule fragments were observed for starch-amino acid complex. An increase in size distribution was obvious after LPT and the size distribution curves provided from a new variety. We found that higher enthalpy and relative crystallinity of the starch-amino acid complex were associated with a higher SDS content. It can be inferred that LPT had a greater impact on the digestion and structural characterization of corn starch mixed with amino acids. Copyright © 2017 Elsevier Ltd. All rights reserved.

Autohydrolysis Pretreatment of Lignocellulosic Biomass for Bioethanol Production

Science.gov (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

Enzymatic saccharification of dilute acid pretreated saline crops for fermentable sugar production

Energy Technology Data Exchange (ETDEWEB)

Zheng, Yi; Zhang, Ruihong [Biological and Agricultural Engineering Department, University of California, Davis One Shields Avenue, Davis, CA 95616 (United States); Pan, Zhongli [Biological and Agricultural Engineering Department, University of California, Davis One Shields Avenue, Davis, CA 95616 (United States); Processed Foods Research Unit, USDA-ARS-WRRC, 800 Buchanan Street, Albany, CA 94710 (United States); Wang, Donghai [Biological and Agricultural Engineering Department, Kansas State University, Manhattan, KS 66506 (United States)

2009-11-15

Four saline crops [athel (Tamarix aphylla L), eucalyptus (Eucalyptus camaldulensis), Jose Tall Wheatgrass (Agropyron elongatum), and Creeping Wild Ryegrass (Leymus triticoides)] that are used in farms for salt uptake from soil and drainage irrigation water have the potential for fuel ethanol production because they don't take a large number of arable lands. Dilute sulfuric acid pretreatment and enzymatic hydrolysis were conducted to select the optimum pretreatment conditions and the best saline crop for further enzymatic hydrolysis research. The optimum dilute acid pretreatment conditions included T = 165 C, t = 8 min, and sulfuric acid concentration 1.4% (w/w). Creeping Wild Ryegrass was decided to be the best saline crop. Solid loading, cellulase and {beta}-glucosidase concentrations had significant effects on the enzymatic hydrolysis of dilute acid pretreated Creeping Wild Ryegrass. Glucose concentration increased by 36 mg/mL and enzymatic digestibility decreased by 20% when the solid loading increased from 4 to 12%. With 8% solid loading, enzymatic digestibility increased by over 30% with the increase of cellulase concentration from 5 to 15 FPU/g-cellulose. Under given cellulase concentration of 15 FPU/g-cellulose, 60% increase of enzymatic digestibility of pretreated Creeping Wild Ryegrass was obtained with the increase of {beta}-glucosidase concentration up to 15 CBU/g-cellulose. With a high solid loading of 10%, fed-batch operation generated 12% and 18% higher enzymatic digestibility and glucose concentration, respectively, than batch process. (author)

Pretreatment and enzymatic hydrolysis of lignocellulosic biomass

Science.gov (United States)

Corredor, Deisy Y.

The performance of soybean hulls and forage sorghum as feedstocks for ethanol production was studied. The main goal of this research was to increase fermentable sugars' yield through high-efficiency pretreatment technology. Soybean hulls are a potential feedstock for production of bio-ethanol due to their high carbohydrate content (≈50%) of nearly 37% cellulose. Soybean hulls could be the ideal feedstock for fuel ethanol production, because they are abundant and require no special harvesting and additional transportation costs as they are already in the plant. Dilute acid and modified steam-explosion were used as pretreatment technologies to increase fermentable sugars yields. Effects of reaction time, temperature, acid concentration and type of acid on hydrolysis of hemicellulose in soybean hulls and total sugar yields were studied. Optimum pretreatment parameters and enzymatic hydrolysis conditions for converting soybean hulls into fermentable sugars were identified. The combination of acid (H2SO4, 2% w/v) and steam (140°C, 30 min) efficiently solubilized the hemicellulose, giving a pentose yield of 96%. Sorghum is a tropical grass grown primarily in semiarid and dry parts of the world, especially in areas too dry for corn. The production of sorghum results in about 30 million tons of byproducts mainly composed of cellulose, hemicellulose, and lignin. Forage sorghum such as brown midrib (BMR) sorghum for ethanol production has generated much interest since this trait is characterized genetically by lower lignin concentrations in the plant compared with conventional types. Three varieties of forage sorghum and one variety of regular sorghum were characterized and evaluated as feedstock for fermentable sugar production. Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM) and X-Ray diffraction were used to determine changes in structure and chemical composition of forage sorghum before and after pretreatment and enzymatic hydrolysis

Detoxification of Corncob Acid Hydrolysate with SAA Pretreatment and Xylitol Production by Immobilized Candida tropicalis

Directory of Open Access Journals (Sweden)

Li-Hong Deng

2014-01-01

Full Text Available Xylitol fermentation production from corncob acid hydrolysate has become an attractive and promising process. However, corncob acid hydrolysate cannot be directly used as fermentation substrate owing to various inhibitors. In this work, soaking in aqueous ammonia (SAA pretreatment was employed to reduce the inhibitors in acid hydrolysate. After detoxification, the corncob acid hydrolysate was fermented by immobilized Candida tropicalis cell to produce xylitol. Results revealed that SAA pretreatment showed high delignification and efficient removal of acetyl group compounds without effect on cellulose and xylan content. Acetic acid was completely removed, and the content of phenolic compounds was reduced by 80%. Furthermore, kinetic behaviors of xylitol production by immobilized C. tropicalis cell were elucidated from corncob acid hydrolysate detoxified with SAA pretreatment and two-step adsorption method, respectively. The immobilized C. tropicalis cell showed higher productivity efficiency using the corncob acid hydrolysate as fermentation substrate after detoxification with SAA pretreatment than by two-step adsorption method in the five successive batch fermentation rounds. After the fifth round fermentation, about 60 g xylitol/L fermentation substrate was obtained for SAA pretreatment detoxification, while about 30 g xylitol/L fermentation substrate was obtained for two-step adsorption detoxification.

The effect of dilute acid pre-treatment process in bioethanol production from durian (Durio zibethinus) seeds waste

Science.gov (United States)

Ghazali, K. A.; Salleh, S. F.; Riayatsyah, T. M. I.; Aditiya, H. B.; Mahlia, T. M. I.

2016-03-01

Lignocellulosic biomass is one of the promising feedstocks for bioethanol production. The process starts from pre-treatment, hydrolysis, fermentation, distillation and finally obtaining the final product, ethanol. The efficiency of enzymatic hydrolysis of cellulosic biomass depends heavily on the effectiveness of the pre-treatment step which main function is to break the lignin structure of the biomass. This work aims to investigate the effects of dilute acid pre-treatment on the enzymatic hydrolysis of durian seeds waste to glucose and the subsequent bioethanol fermentation process. The yield of glucose from dilute acid pre-treated sample using 0.6% H2SO4 and 5% substrate concentration shows significant value of 23.4951 g/L. Combination of dilute acid pre-treatment and enzymatic hydrolysis using 150U of enzyme able to yield 50.0944 g/L of glucose content higher compared to normal pre-treated sample of 8.1093 g/L. Dilute acid pre-treatment sample also shows stable and efficient yeast activity during fermentation process with lowest glucose content at 2.9636 g/L compared to 14.7583g/L for normal pre-treated sample. Based on the result, it can be concluded that dilute acid pre-treatment increase the yield of ethanol from bioethanol production process.

Standardized Ileal Amino Acid Digestibility of Corn, Corn Distillers' Dried Grains with Solubles, Wheat Middlings, and Bakery By-Products in Broilers and Laying Hens.

Science.gov (United States)

Adedokun, S A; Jaynes, P; Payne, R L; Applegate, T J

2015-10-01

Standardized ileal amino acid digestibility (SIAAD) of 5 samples of corn distillers dried grain with solubles (DDGS), 5 samples of bakery by-products (BBP), 3 samples of corn, and 1 sample of wheat middlings (WM) were evaluated in broilers and laying hens. Diets containing each of the 14 feed ingredients were evaluated in 21 day-old broiler chickens. The DDGS and BBP containing diets were fed to 30-week-old laying hens, while corn and wheat middling were evaluated in 50-week-old laying hens. All the diets were semi-purified with each feed ingredient being the only source of amino acid (AA). To obtain SIAAD values, apparent ileal AA digestibility was corrected for basal ileal endogenous AA losses using values generated from broilers and laying hens fed a nitrogen-free diet. Ileal crude protein digestibility for the 5 DDGS samples was higher (P digestibility values for broilers were higher (P digestibility for corn 1 was higher (P digestibility exists between different samples of DDGS. Differences in SIAAD between broilers and laying hens were observed in some samples of DDGS and BBP. © 2015 Poultry Science Association Inc.

Enhancing methane production of corn stover through a novel way: sequent pretreatment of potassium hydroxide and steam explosion.

Science.gov (United States)

Li, Jianghao; Zhang, Ruihong; Siddhu, Muhammad Abdul Hanan; He, Yanfeng; Wang, Wen; Li, Yeqing; Chen, Chang; Liu, Guangqing

2015-04-01

Getting over recalcitrance of lignocellulose is effective way to fuel production from lignocellulosic biomass. In current work, different pretreatments were applied to enhance the digestibility of corn stover (CS). Results showed that steam explosion (SE)-treated CS produced maximal methane yield (223.2 mL/gvs) at 1.2 MPa for 10 min, which was 55.2% more than untreated (143.8 mL/gvs). Whereas 1.5% KOH-treated CS produced maximum methane yield of 208.6 mL/gvs, and significantly (αpotassium hydroxide and steam explosion (SPPE) (1.5% KOH-1.2 MPa, 10 min) achieved a very significant (α<0.01) improvement (80.0%) of methane yield (258.8 mL/gvs) compared with untreated CS. Methane production could be well explained by the first-order and modified Gompertz models. Besides, SEM, FTIR, and XRD analyses validated structural changes of CS after SPPE. SPPE might be a promising method to pretreat CS in the future AD industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of different extraction methods for giberelic acid obtention from corn (Zea mays L. germinated seeds

Directory of Open Access Journals (Sweden)

Juan David Rivera

2017-05-01

Full Text Available Corn (Zea mays L. is the second most cultivated cereal in the world and is use as raw material for different kind of industries. To date no reports about obtaining giberellic acid (GA3 from corn have been found. In the present study two methods for extracting solid samples were evaluated: lixiviation and dynamic sonication-assisted solvent extraction (DSASE, for obtaining giberellic acid from corn germinated seeds. In lixiviation, the physical method (agitation and sonication, solvent, and time were the parameters analyzed; while in DSASE the variables were: solvent, flow, and time. The most efficient technique was DSASE employing acetonitrile-formic acid 5% (80:20, v:v as solvent at a flow of 0.4 mL/min for 25,0 min, obtaining a concentration 30.012 mg/kg giberellic acid. The identification and quantification were performed by high performance liquid chromatography (HPLC with diode array detector (DAD. These results showed that dynamic sonication-assisted solvent extraction (DSASE is a novel and powerful alternative technique for obtaining giberellic acid, because of its high efficiency; low solvent consumption and simplicity in obtaining the extract.

Ethanol production from industrial hemp: effect of combined dilute acid/steam pretreatment and economic aspects

DEFF Research Database (Denmark)

Gunnarsson, Ingólfur Bragi; Svensson, Sven-Erik; Prade, Thomas

2014-01-01

In the present study, combined steam (140-180 °C) and dilute-acid pre-hydrolysis (0.0-2.0%) were applied to industrial hemp (Cannabis sativa L.), as pretreatment for lignocellulosic bioethanol production. The influence of the pretreatment conditions and cultivation type on the hydrolysis and etha......In the present study, combined steam (140-180 °C) and dilute-acid pre-hydrolysis (0.0-2.0%) were applied to industrial hemp (Cannabis sativa L.), as pretreatment for lignocellulosic bioethanol production. The influence of the pretreatment conditions and cultivation type on the hydrolysis...... pretreated at the optimal conditions showed positive economic results. The type of hemp cultivation (organic or conventional) did not influence significantly the effectiveness of the pretreatment and subsequent enzymatic hydrolysis and ethanol fermentation....

Nephroprotective effect of Corn Silk extract on oxalic acid-induced nephrocalcinosis in rabbit model

OpenAIRE

Faruk Hassan Al-Jawad; Rafi Abdul Majeed Al-Razzuqi; Zainab Awaen Al-Ebady; Thulfuqar Abdul Majeed Al-Razzuqi

2012-01-01

ABSTRACT Background : Nephrocalcinosis is a state of deposition of calcium phosphate or oxalate in the renal parenchyma. It may occur in patients with renal tubular acidosis, vitamin D intoxication, and hyperparathyroidism. Corn silk was used in traditional Chinese medicine to relieve renal pains. Aim: To evaluate the effect of Corn silk aqueous extract in reducing calcium deposits from renal parenchyma in oxalic acid-induced nephrocalcinosis model. Materials and methods: Fourteen healthy...

Kinetic study of enzymatic hydrolysis of acid-pretreated coconut coir

Science.gov (United States)

Fatmawati, Akbarningrum; Agustriyanto, Rudy

2015-12-01

Biomass waste utilization for biofuel production such as bioethanol, has become more prominent currently. Coconut coir is one of lignocellulosic food wastes, which is abundant in Indonesia. Bioethanol production from such materials consists of more than one step. Pretreatment and enzymatic hydrolysis is crucial steps to produce sugar which can then be fermented into bioethanol. In this research, ground coconut coir was pretreated using dilute sulfuric acid at 121°C. This pretreatment had increased the cellulose content and decreased the lignin content of coconut coir. The pretreated coconut coir was hydrolyzed using a mix of two commercial cellulase enzymes at pH of 4.8 and temperature of 50°C. The enzymatic hydrolysis was conducted at several initial coconut coir slurry concentrations (0.1-2 g/100 mL) and reaction times (2-72 hours). The reducing sugar concentration profiles had been produced and can be used to obtain reaction rates. The highest reducing sugar concentration obtained was 1,152.567 mg/L, which was produced at initial slurry concentration of 2 g/100 mL and 72 hours reaction time. In this paper, the reducing sugar concentrations were empirically modeled as a function of reaction time using power equations. Michaelis-Menten kinetic model for enzymatic hydrolysis reaction is adopted. The kinetic parameters of that model for sulfuric acid-pretreated coconut coir enzymatic hydrolysis had been obtained which are Vm of 3.587×104 mg/L.h, and KM of 130.6 mg/L.

Efficient saccharification by pretreatment of bagasse pith with ionic liquid and acid solutions simultaneously

International Nuclear Information System (INIS)

Wang, Gang; Zhang, Suping; Xu, Wenjuan; Qi, Wei; Yan, Yongjie; Xu, Qingli

2015-01-01

Highlights: • Bagasse pith was pretreated by BMIMCl solution containing HCl and water. • Hemicellulose was hydrolyzed to reducing sugars by HCl to maximize total sugar yield. • Cellulose was dissolved by BMIMCl and 95% of cellulose recovery was obtained. • The recovered cellulose was disrupted which is conducive to cellulase hydrolysis. • The total sugars yield is 89.9% obtained from pretreatment and cellulase hydrolysis. - Abstract: Hydrolysis of hemicellulose and disruption of cellulose during pretreatment process are conducive to the following cellulase hydrolysis performance. In this work, bagasse pith was first pretreated by 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) solution containing 0–1.2% hydrochloric acid (HCl) and 30% water. The water (30%) added into the acidic ionic liquid (IL) solutions led to an increase in the biomass loading up to a biomass/IL solutions ratio of 1:10 (wt.%). Hemicellulose was hydrolyzed to reducing sugars by HCl and cellulose was dissolved by [BMIM]Cl. In this process, 76.9% of hemicellulose conversion and 95% of cellulose recovery were obtained. The pretreated bagasse pith was then followed by hydrolysis with commercially available enzymes. The effects of pretreatment temperature, reaction time and acid concentration on cellulase hydrolysis of pretreated bagasse pith were investigated. Pretreatment of bagasse pith with [BMIM]Cl solutions containing 1.0% HCl at 120 °C for 30 min resulted in the glucose concentration of 92.3 g/l and yield of 94.5% after 72 h of cellulase hydrolysis. The maximum total reducing sugars yield reached to 89.9% after pretreatment and cellulase hydrolysis

Pretreatment of wheat straw by nonionic surfactant-assisted dilute acid for enhancing enzymatic hydrolysis and ethanol production.

Science.gov (United States)

Qi, Benkun; Chen, Xiangrong; Wan, Yinhua

2010-07-01

Pretreating wheat straw (WS) with combined use of varied sulfuric acid concentration (0-3%, w/v) and Tween 20 concentration (0-1%) was investigated in an attempt to enhance the hydrolysis and fermentability of pretreated WS. Enzymatic hydrolysis yield of glucan and xylan and ethanol production by simultaneous saccharification and fermentation (SSF) of water-insoluble solids (WIS) were significantly affected by the amount of Tween 20 added during acid pretreatment. Any further addition of Tween 20 in either hydrolysis stage or fermentation stage only led to small increase in glucan conversion and ethanol production. Determination of adsorption of cellulases during hydrolysis showed that Tween 20-assisted acid treated straw solution contained more free cellulases than individual acid treated straw solution, indicating that modification of lignin surface by Tween 20 added during pretreatment likely occurred. In addition, the effects of pretreatment conditions on overall recovery of glucose and xylose after pretreatment and enzymatic hydrolysis were also investigated. Copyright 2010 Elsevier Ltd. All rights reserved.

Production of lactic acid from corn cobs through fermentation lactobacillus delbruekii

International Nuclear Information System (INIS)

Ali, Z.; Anjum, M.; Zahoor, T.

2007-01-01

Corn cobs were used as the source of reducing sugars for conversion into lactic acid through fermentation by a local strain of Lactobacillus delbruekii, under varying parameters of time, temperature, pH and glucose concentration, The production of lactic acid significantly increased with increase in Ph, fermentation time and glucose concentration (1-5%) and was significantly high (8.40 g/1) at pH 6, while significantly low (7.67 g/1) at pH 5. (author)

The effect of acid hydrolysis pretreatment on crystallinity and solubility of kenaf cellulose membrane

Energy Technology Data Exchange (ETDEWEB)

Saidi, Anis Syuhada Mohd; Zakaria, Sarani; Chia, Chin Hua; Jaafar, Sharifah Nabihah Syed; Padzil, Farah Nadia Mohammad [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

2015-09-25

Cellulose was extracted from kenaf core pulp (KCP) by series of bleaching steps in the sequence (DEED) where D and E are referred as acid and alkali treatment. The bleached kenaf pulp (BKCP) is then pretreated with acid hydrolysis at room temperature for 1 and 3 h respectively. The pretreated cellulose is dissolved in lithium hydroxide/urea (LiOH/urea) and cellulose solution produced was immersed in distilled water bath. BKCP without treatment was also conducted for comparison purpose. The effects of acid hydrolysis pretreatment on solubility and crystallinity are investigated. Higher solubility of cellulose solution is achieved for treated samples. Cellulose II formation and crystallinity index of the cellulose membrane were determined by X-ray diffraction (XRD)

The effect of acid hydrolysis pretreatment on crystallinity and solubility of kenaf cellulose membrane

International Nuclear Information System (INIS)

Saidi, Anis Syuhada Mohd; Zakaria, Sarani; Chia, Chin Hua; Jaafar, Sharifah Nabihah Syed; Padzil, Farah Nadia Mohammad

2015-01-01

Cellulose was extracted from kenaf core pulp (KCP) by series of bleaching steps in the sequence (DEED) where D and E are referred as acid and alkali treatment. The bleached kenaf pulp (BKCP) is then pretreated with acid hydrolysis at room temperature for 1 and 3 h respectively. The pretreated cellulose is dissolved in lithium hydroxide/urea (LiOH/urea) and cellulose solution produced was immersed in distilled water bath. BKCP without treatment was also conducted for comparison purpose. The effects of acid hydrolysis pretreatment on solubility and crystallinity are investigated. Higher solubility of cellulose solution is achieved for treated samples. Cellulose II formation and crystallinity index of the cellulose membrane were determined by X-ray diffraction (XRD)

40 CFR 406.26 - Pretreatment standards for new sources.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for new sources. 406.26 Section 406.26 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Dry Milling Subcategory § 406.26 Pretreatment...

40 CFR 406.16 - Pretreatment standards for new sources.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for new sources. 406.16 Section 406.16 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Wet Milling Subcategory § 406.16 Pretreatment...

Pretreatment of grass waste using combined ionizing radiation-acid treatment for enhancing fermentative hydrogen production.

Science.gov (United States)

Yang, Guang; Wang, Jianlong

2018-05-01

In this study, the combined ionizing radiation-acid pretreatment process was firstly applied to enhance hydrogen fermentation of grass waste. Results showed that the combined pretreatment synergistically enhanced hydrogen fermentation of grass waste. The SCOD and soluble polysaccharide contents of grass waste increased by 1.6 and 2.91 times after the combined pretreatment, respectively. SEM observation and crystallinity test showed the combined pretreatment effectively disrupted the grass structure. Owing to the more favorable substrate conditions, the hydrogen yield achieved 68 mL/g-dry grass added after the combined pretreatment, which was 161.5%, 112.5% and 28.3% higher than those from raw, ionizing radiation pretreated and acid pretreated grass waste, respectively. The VS removal also increased from 13.9% to 25.6% by the combined pretreatment. Microbial community analysis showed that the abundance of dominant hydrogen producing genus Clostridium sensu stricto 1 increased from 37.9% to 69.4% after the combined pretreatment, which contributed to more efficient hydrogen fermentation. Copyright © 2018 Elsevier Ltd. All rights reserved.

BIOFUEL FROM CORN STOVER

Directory of Open Access Journals (Sweden)

Ljiljanka Tomerlin

2003-12-01

Full Text Available This paper deals with production of ethyl alcohol (biofuel from corn stover acid hydrolysate by yeasts, respectively at Pichia stipitis y-7124 and Pachysolen tannophilus y-2460 and Candida shehatae y-12856. Since moist corn stover (Hybryds 619 is proving to decomposition by phyllospheric microflora. It was (conserved spattered individually by microbicids: Busan-90, Izosan-G and formalin. In form of prismatic bales, it was left in the open air during 6 months (Octobar - March. At the beginning and after 6 months the microbiological control was carried out. The only one unspattered (control and three stover corn bals being individually spattered by microbicids were fragmented and cooked with sulfur acid. The obtained four acid hydrolysates are complex substratums, containing, apart from the sugars (about 11 g dm-3 pentosa and about 5.4 g dm-3 hexose, decomposite components as lignin, caramel sugars and uronic acids. By controlling the activity of the mentioned yeasts it was confirmed that yeasts Pichia stipitis y-7124 obtained best capability of ethyl alcohol production from corn stover acid hydrolysate at 0.23 vol. % to 0.49 vol. %.

Process analysis and optimization of simultaneous saccharification and co-fermentation of ethylenediamine-pretreated corn stover for ethanol production.

Science.gov (United States)

Qin, Lei; Zhao, Xiong; Li, Wen-Chao; Zhu, Jia-Qing; Liu, Li; Li, Bing-Zhi; Yuan, Ying-Jin

2018-01-01

Improving ethanol concentration and reducing enzyme dosage are main challenges in bioethanol refinery from lignocellulosic biomass. Ethylenediamine (EDA) pretreatment is a novel method to improve enzymatic digestibility of lignocellulose. In this study, simultaneous saccharification and co-fermentation (SSCF) process using EDA-pretreated corn stover was analyzed and optimized to verify the constraint factors on ethanol production. Highest ethanol concentration was achieved with the following optimized SSCF conditions at 6% glucan loading: 12-h pre-hydrolysis, 34 °C, pH 5.4, and inoculum size of 5 g dry cell/L. As glucan loading increased from 6 to 9%, ethanol concentration increased from 33.8 to 48.0 g/L, while ethanol yield reduced by 7%. Mass balance of SSCF showed that the reduction of ethanol yield with the increasing solid loading was mainly due to the decrease of glucan enzymatic conversion and xylose metabolism of the strain. Tween 20 and BSA increased ethanol concentration through enhancing enzymatic efficiency. The solid-recycled SSCF process reduced enzyme dosage by 40% (from 20 to 12 mg protein/g glucan) to achieve the similar ethanol concentration (~ 40 g/L) comparing to conventional SSCF. Here, we established an efficient SSCF procedure using EDA-pretreated biomass. Glucose enzymatic yield and yeast viability were regarded as the key factors affecting ethanol production at high solid loading. The extensive analysis of SSCF would be constructive to overcome the bottlenecks and improve ethanol production in cellulosic ethanol refinery.

Treatment of some Textile Industrial Effluents using Dry Corn Stalk ...

African Journals Online (AJOL)

Corn stalk ground to various mesh sizes was used to treat textile effluents obtained from three different industries. These effluents were first pretreated with alum and then charcoal; passing the water through a column, (20cm long and 5cm diameter) containing the ground corn stalk of size diameters of 300mm, 355mm ...

Pretreatment of various feedstocks for lactic acid production: detection of sugars, organic acids and furanics in liquid fractions

NARCIS (Netherlands)

Harmsen, P.F.H.; Lips, S.J.J.; Bakker, R.R.C.

2012-01-01

Barley straw, sugarcane bagasse and empty fruit bunches were pretreated under acid- and alkaline conditions. Solid phase was separated from the liquid phase and the concentration of dissolved monomeric sugars, organic acids and furanics was determined. Acid hydrolysis yielded monomeric xylose

Kinetics of leather dyeing pretreated with enzymes: role of acid protease.

Science.gov (United States)

Kanth, Swarna Vinodh; Venba, Rajangam; Jayakumar, Gladstone Christopher; Chandrababu, Narasimhan Kannan

2009-04-01

In the present investigation, kinetics of dyeing involving pretreatment with acid protease has been presented. Application of acid protease in dyeing process resulted in increased absorption and diffusion of dye into the leather matrix. Enzyme treatment at 1% concentration, 60 min duration and 50 degrees C resulted in maximum of 98% dye exhaustion and increased absorption rate constants. The final exhaustion (C(infinity)) for the best fit of CI Acid Black 194 dye has been 98.5% with K and r2 values from the modified Cegarra-Puente isotherm as 0.1033 and 0.0631. CI Acid Black 194 being a 2:1 metal complex acid dye exhibited higher absorption rate than the acid dye CI Acid Black 210. A reduction in 50% activation energy calculated from Arrhenius equation has been observed in enzyme assisted dyeing process of both the dyes that substantiates enhanced dye absorption. The absorption rate constant calculated with modified Cegarra-Puente equation confirm higher rate constants and faster kinetics for enzyme assisted dyeing process. Enzyme treated leather exhibited richness of color and shade when compared with control. The present study substantiates the essential role of enzyme pretreatment as an eco-friendly leather dyeing process.

Multifaceted metabolomics approaches for characterization of lignocellulosic biomass degradation products formed during ammonia fiber expansion pretreatment

Science.gov (United States)

Vismeh, Ramin

to 45-50 % of ammonia that is lost during the pretreatment. Methodology for identification, detection and quantification of various diferulate cross-linkers in forms of Di-Acids (Di-Ac), Acid-Amide (Ac-Am), and Di-Amides (Di-Am) in AFEX and NaOH treated corn stover using ultrahigh performance liquid chromatography/tandem mass spectrometry (LC/MS/MS) is presented. Characterization of isomeric diferulates was based on the distinguishing fragments formed upon collision induced dissociation (CID) of [M+H]+ ions of each diferulate isomer. LC separations combined with quasi-simultaneous acquisition of mass spectra at multiple collision energies provide fast spectrum acquisition using a time-of-flight (TOF) mass analyzer. This approach, called mux-CID, generates molecular and fragment ion mass information at different collision energies for molecular and adduct ions of oligosaccharides in a single analysis. Non-selective CID facilitated characterization of glucans and arabinoxylans in the AFEXTCS extracts. A LC/MS gradient based on multiplexed-CID detection was developed and applied to profile oligosaccharides in AFEXTCS extract. This method detected glucans with degree of polymerization (DP) from 2 to 22 after solid phase extraction (SPE) enrichment using porous graphitized carbon (PGC), which proved essential for recoveries of specific oligosaccharides. Arabinoxylans were also detected and partially characterized using this strategy after hydrolysis using xylanase. A relative quantification based on peak areas showed removal of almost 85% of the acetate esters of arabinoxylans after AFEX.

Maximizing cellulosic ethanol potentials by minimizing wastewater generation and energy consumption: Competing with corn ethanol.

Science.gov (United States)

Liu, Gang; Bao, Jie

2017-12-01

Energy consumption and wastewater generation in cellulosic ethanol production are among the determinant factors on overall cost and technology penetration into fuel ethanol industry. This study analyzed the energy consumption and wastewater generation by the new biorefining process technology, dry acid pretreatment and biodetoxification (DryPB), as well as by the current mainstream technologies. DryPB minimizes the steam consumption to 8.63GJ and wastewater generation to 7.71tons in the core steps of biorefining process for production of one metric ton of ethanol, close to 7.83GJ and 8.33tons in corn ethanol production, respectively. The relatively higher electricity consumption is compensated by large electricity surplus from lignin residue combustion. The minimum ethanol selling price (MESP) by DryPB is below $2/gal and falls into the range of corn ethanol production cost. The work indicates that the technical and economical gap between cellulosic ethanol and corn ethanol has been almost filled up. Copyright © 2017 Elsevier Ltd. All rights reserved.

Understanding the synergistic effect and the main factors influencing the enzymatic hydrolyzability of corn stover at low enzyme loading by hydrothermal and/or ultrafine grinding pretreatment.

Science.gov (United States)

Zhang, Haiyan; Li, Junbao; Huang, Guangqun; Yang, Zengling; Han, Lujia

2018-05-26

A thorough assessment of the microstructural changes and synergistic effects of hydrothermal and/or ultrafine grinding pretreatment on the subsequent enzymatic hydrolysis of corn stover was performed in this study. The mechanism of pretreatment was elucidated by characterizing the particle size, specific surface area (SSA), pore volume (PV), average pore size, cellulose crystallinity (CrI) and surface morphology of the pretreated samples. In addition, the underlying relationships between the structural parameters and final glucose yields were elucidated, and the relative significance of the factors influencing enzymatic hydrolyzability were assessed by principal component analysis (PCA). Hydrothermal pretreatment at a lower temperature (170 °C) combined with ultrafine grinding achieved a high glucose yield (80.36%) at a low enzyme loading (5 filter paper unit (FPU)/g substrate) which is favorable. The relative significance of structural parameters in enzymatic hydrolyzability was SSA > PV > average pore size > CrI/cellulose > particle size. PV and SSA exhibited logarithmic correlations with the final enzymatic hydrolysis yield. Copyright © 2018 Elsevier Ltd. All rights reserved.

Enhanced furfural production from raw corn stover employing a novel heterogeneous acid catalyst.

Science.gov (United States)

Li, Wenzhi; Zhu, Yuanshuai; Lu, Yijuan; Liu, Qiyu; Guan, Shennan; Chang, Hou-Min; Jameel, Hasan; Ma, Longlong

2017-12-01

With the aim to enhance the direct conversion of raw corn stover into furfural, a promising approach was proposed employing a novel heterogeneous strong acid catalyst (SC-CaC t -700) in different solvents. The novel catalyst was characterized by elemental analysis, N 2 adsorption-desorption, FT-IR, XPS, TEM and SEM. The developed catalytic system demonstrated superior efficacy for furfural production from raw corn stover. The effects of reaction temperature, residence time, catalyst loading, substrate concentration and solvent were investigated and optimized. 93% furfural yield was obtained from 150mg corn stover at 200°C in 100min using 45mg catalyst in γ-valerolactone (GVL). In comparison, 51.5% furfural yield was achieved in aqueous media under the same conditions (200°C, 5h, and 45mg catalyst), which is of great industrial interest. Furfural was obtained from both hemicelluloses and cellulose in corn stover, which demonstrated a promising routine to make the full use of biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

High solid simultaneous saccharification and fermentation of wet oxidized corn stover to ethanol

DEFF Research Database (Denmark)

Varga, E.; Klinke, H.B.; Reczey, K.

2004-01-01

In this study ethanol was produced from corn stover pretreated by alkaline and acidic wet oxidation (WO) (195 degreesC, 15 min, 12 bar oxygen) followed by nonisothermal simultaneous saccharification and fermentation (SSF). In the first step of the SSF, small amounts of cellulases were added at 50...... increase of substrate concentration reduced the ethanol yield significant as a result of insufficient mass transfer. It was also shown that the fermentation could be followed with an easy monitoring system based on the weight loss of the produced CO2. (C) 2004 Wiley Periodicals, Inc....

Enhancing sludge biodegradability and volatile fatty acid production by tetrakis hydroxymethyl phosphonium sulfate pretreatment.

Science.gov (United States)

Wu, Qing-Lian; Guo, Wan-Qian; Bao, Xian; Yin, Ren-Li; Feng, Xiao-Chi; Zheng, He-Shan; Luo, Hai-Chao; Ren, Nan-Qi

2017-09-01

A new pretreatment method based on tetrakis hydroxymethyl phosphonium sulfate (THPS) biocide was tried to enhance sludge disintegration, and improved sludge biodegradability and subsequent volatile fatty acid (VFA) production. Sludge activity decreased to less than 10% after 2 days pretreatment using 20mg/g-TSS THPS, which also obviously destroyed EPS and cell membrane, and dissolved more biodegradable substances (48.8%) than raw sludge (19.7%). Moreover, 20mg/g-TSS THPS pretreatment shortened fermentation time to 4days and improved VFA production to 2778mg COD/L (4.35 times than that in control). Therein, the sum of n-butyric, n-valeric and iso-valeric acids unexpectedly accounted for 60.5% of total VFA (only 20.1% of that in control). The more high molecular weight VFAs (C4-C5) than low molecular VFAs (C2-C3) resulted from THPS pretreatment benefited to subsequent medium-chain volatile acids (C6-C12) generation to realize the separation and recovery of organic carbon more efficiently. Copyright © 2017. Published by Elsevier Ltd.

Compatibility of High-Moisture Storage for Biochemical Conversion of Corn Stover: Storage Performance at Laboratory and Field Scales

Science.gov (United States)

Wendt, Lynn M.; Murphy, J. Austin; Smith, William A.; Robb, Thomas; Reed, David W.; Ray, Allison E.; Liang, Ling; He, Qian; Sun, Ning; Hoover, Amber N.; Nguyen, Quang A.

2018-01-01

Wet anaerobic storage of corn stover can provide a year-round supply of feedstock to biorefineries meanwhile serving an active management approach to reduce the risks associated with fire loss and microbial degradation. Wet logistics systems employ particle size reduction early in the supply chain through field-chopping which removes the dependency on drying corn stover prior to baling, expands the harvest window, and diminishes the biorefinery size reduction requirements. Over two harvest years, in-field forage chopping was capable of reducing over 60% of the corn stover to a particle size of 6 mm or less. Aerobic and anaerobic storage methods were evaluated for wet corn stover in 100 L laboratory reactors. Of the methods evaluated, traditional ensiling resulted in <6% total solid dry matter loss (DML), about five times less than the aerobic storage process and slightly less than half that of the anaerobic modified-Ritter pile method. To further demonstrate the effectiveness of the anaerobic storage, a field demonstration was completed with 272 dry tonnes of corn stover; DML averaged <5% after 6 months. Assessment of sugar release as a result of dilute acid or dilute alkaline pretreatment and subsequent enzymatic hydrolysis suggested that when anaerobic conditions were maintained in storage, sugar release was either similar to or greater than as-harvested material depending on the pretreatment chemistry used. This study demonstrates that wet logistics systems offer practical benefits for commercial corn stover supply, including particle size reduction during harvest, stability in storage, and compatibility with biochemical conversion of carbohydrates for biofuel production. Evaluation of the operational efficiencies and costs is suggested to quantify the potential benefits of a fully-wet biomass supply system to a commercial biorefinery. PMID:29632861

Compatibility of High-Moisture Storage for Biochemical Conversion of Corn Stover: Storage Performance at Laboratory and Field Scales

Directory of Open Access Journals (Sweden)

Lynn M. Wendt

2018-03-01

Full Text Available Wet anaerobic storage of corn stover can provide a year-round supply of feedstock to biorefineries meanwhile serving an active management approach to reduce the risks associated with fire loss and microbial degradation. Wet logistics systems employ particle size reduction early in the supply chain through field-chopping which removes the dependency on drying corn stover prior to baling, expands the harvest window, and diminishes the biorefinery size reduction requirements. Over two harvest years, in-field forage chopping was capable of reducing over 60% of the corn stover to a particle size of 6 mm or less. Aerobic and anaerobic storage methods were evaluated for wet corn stover in 100 L laboratory reactors. Of the methods evaluated, traditional ensiling resulted in <6% total solid dry matter loss (DML, about five times less than the aerobic storage process and slightly less than half that of the anaerobic modified-Ritter pile method. To further demonstrate the effectiveness of the anaerobic storage, a field demonstration was completed with 272 dry tonnes of corn stover; DML averaged <5% after 6 months. Assessment of sugar release as a result of dilute acid or dilute alkaline pretreatment and subsequent enzymatic hydrolysis suggested that when anaerobic conditions were maintained in storage, sugar release was either similar to or greater than as-harvested material depending on the pretreatment chemistry used. This study demonstrates that wet logistics systems offer practical benefits for commercial corn stover supply, including particle size reduction during harvest, stability in storage, and compatibility with biochemical conversion of carbohydrates for biofuel production. Evaluation of the operational efficiencies and costs is suggested to quantify the potential benefits of a fully-wet biomass supply system to a commercial biorefinery.

Ethanol Fermentation of Various Pretreated and Hydrolyzed Substrates at Low Initial pH

Science.gov (United States)

Kádár, Zsófia; Maltha, San Feng; Szengyel, Zsolt; Réczey, Kati; de Laat, Wim

Lignocellulosic materials represent an abundant feedstock for bioethanol production. Because of their complex structure pretreatment is necessary to make it accessible for enzymatic attack. Steam pretreatment with or without acid catalysts seems to be one of the most promising techniques, which has already been applied for large variety of lignocellulosics in order to improve enzymatic digestibility. During this process a range of toxic compounds (lignin and sugar degradation products) are formed which inhibit ethanol fermentation. In this study, the toxicity of hemicellulose hydrolysates obtained in the steam pretreatment of spruce, willow, and corn stover were investigated in ethanol fermentation tests using a yeast strain, which has been previously reported to have a resistance to inhibitory compounds generated during steam pretreatment. To overcome bacterial contamination, fermentations were carried out at low initial pH. The fermentability of hemicellulose hydrolysates of pretreated lignocellulosic substrates at low pH gave promising results with the economically profitable final 5 vol% ethanol concentration corresponding to 85% of theoretical. Adaptation experiments have shown that inhibitor tolerance of yeast strain can be improved by subsequent transfer of the yeast to inhibitory medium.

The palatability of corn oil and linoleic acid to mice as measured by short-term two-bottle choice and licking tests.

Science.gov (United States)

Yoneda, Takeshi; Saitou, Katsuyoshi; Mizushige, Takafumi; Matsumura, Shigenobu; Manabe, Yasuko; Tsuzuki, Satoshi; Inoue, Kazuo; Fushiki, Tohru

2007-06-08

Free fatty acids (FFAs) were reported to be recognized in the oral cavity and possibly involved in fatty foods recognition. To understand the importance of oil recognition in the oral cavity, we investigated the effect of various concentrations of a fatty acid or corn oil on fluid intake as well as mice's preferences in a two-bottle choice test and a licking test. Linoleic acid (LA), which is a main component of corn oil, was used as a representative FFA. In the two-bottle choice test between a pair of different concentrations of corn oil, the mice consistently adopted the higher concentration of corn oil. In the licking test for corn oil, the licking rates for the serial concentration of corn oils (0, 1, 5, 10 and 100%) were increased in a concentration-dependent manner. On the other hand, in the two-bottle test for a pair of different concentrations of LA (0, 0.125, 0.25 and 1%), 0.25% and 1% LA were preferred to mineral oil, but 0.25% and 1% LA were preferred equally in mice. In the licking test for LA, the mice showed the largest number of initial lickings for the 1% LA, while the licking rates for the high concentration of LA decreased. These results suggest that mice could discriminate the concentration of corn oil and LA in the oral cavity. We also suggest that pure corn oil is a highly preferable solution, while an optimal concentration of LA according to the preferences of mice is a low-range concentration (0.25-1%).

Behavior of 15N-labelled amino acids in germinated corn

International Nuclear Information System (INIS)

Samukawa, Kisaburo; Yamaguchi, Masuro

1979-01-01

By investigating the rise and fall of 15 N-labelled amino acids in germinated corns, the behavior of amino radicals in free amino acids, the influence of the hydrolysis products of stored proteins on free amino acids and the change from heterotrophy to autotrophy of seeds were clarified. The amount of amino acid production depending on external nitrogen was very small in the early period of germination. 15 N incorporation into proline was not observed in the early period of germination, which suggested that the proline may be nitrogen-storing source. Most of the amino-state nitrogen of asparagine accumulated at the time of germination was internal nitrogen, and this fact suggested that aspartic acid serve as the acceptor of ammonia produced in the early stage of germination. 15 N content increased significantly on 9 th day after germination, and decreased on 12 th day. These facts prove that there are always active decomposition and production of protein in plant body. (Kobatake, H.)

Ácido fítico de híbridos de milho e alguns produtos industrializados = Phytic acid in corn hybrids and in some industrialized corn products

Directory of Open Access Journals (Sweden)

Tatiana Shizue Fukuji

2008-01-01

Full Text Available O ácido fítico (AF ou mio-inositol hexafosfato está presente principalmente em cereais, e o germe de milho apresenta teor elevado, com cerca de 6,0 a 7,0% em base seca. Devido a sua propriedade quelante com metais di e tri-valentes, o AF apresenta capacidade antioxidante com eficaz atuação na inibição de reações de oxidação. O teor de AF foi determinado no germe e endosperma de 11 híbridos de milhos, cultivados no Estado do Paraná, e em diferentes produtos industrializados de milho. Os germes de híbridos de milho foram caracterizados como componentes do milho, com elevado teor e osendospermas com baixo teor de AF. Os produtos derivados de milho, elaborados basicamente com endosperma tais como canjica, creme de milho, farinha de milho e fubá fino, apresentaram menor teor de AF, enquanto aqueles originários dos germes desengordurado, fino, gordo e película de milho apresentaram maior teor de AF.Phytic acid (PA, also known as myoinositol hexaphosphate, is found mainly in cereal grains. Corn germ has high concentrations of PA – from 6.0 to 7.0% on a dry weight basis. Due to its chelating properties on di- and trivalent metals, PA has antioxidantattributes, effectively inhibiting oxidation reactions. In this study, PA levels were determined in the germ and endosperm of eleven corn hybrids cultivate in Paraná State (Brazil, and also in several industrialized corn products. Corn hybrid germs were characterized as corn components with high PA levels, whereas endosperms featuredlow levels of PA. Corn-based industrialized products, derived mostly from corn endosperm (such as canjica, creamed corn, corn flour and cornmeal featured the lowest PA values. Conversely, defatted corn germs and corn cuticle showed the highest PA levels.

Improvement of Haramay Fiber by Pre-treatment of Retting Process withPhosphoric Acid

International Nuclear Information System (INIS)

Kuntari-Sasas; Neni-Rustini Eriawati

2000-01-01

Haramay as bast fiber contains of cellulose fiber as the main part, mixedwith hemi cellulose, pectin, and lignin as binding material for cellulosefiber to keep it together in the bundle form. For textile material, this bastfiber has to be freed from its binding material, called as retting process,before subjecting to scouring, dyeing and finishing process in textileindustry. In the retting process the dissolve of binding material can be doneeither by using enzyme in bio technology or extraction with strong alkalinecondition in common technology. Using sodium hydroxide for dissolving thebinding material can be carried out easily with good dissolving ability, butcan render the strength retention of the cellulose fiber. Pre-treatment ofthe bast fiber with phosphoric acid (H 3 PO 4 ), is expected to hydrolyze someof the binding materials that can not be dissolved in alkaline condition,including natural pigment that colored the fiber with creamy white. In thisstudy, the pre-treatment process before retting with phosphoric acid wascarried out in various condition, such as concentration of phosphoric acid (5ml/l- 25 ml/l), time and temperature of pre-treatment (1-3 hours at 50 o C or12-24 hours at room temperature), followed by neutralization in dilutealkaline. The retting process was carried out by means of scouring in variousconcentration of sodium hydroxide (NaOH 38 o Be, 10 ml/l-30 m/l), and then wascontinued with bleaching process in hydrogen peroxide solution. Aftercarrying out those experiment, the bast fiber that called haramay wassubjected to testing for weight reduction, strength retention and degree ofwhiteness. From the testing results it is concluded that pre-treatment withphosphoric acid can increase the weight reduction, strength retention ortenacity and degree of whiteness of haramay fiber compared to the oneswithout pre-treatment with phosphoric acid. The best result was obtained bypre-treatment with 5 ml/l H 3 PO 4 at 50 o C for 2 hours, continued by

Pretreatment by radiation and acids of chaff and its effect on enzymatic hydrolysis of cellulose

International Nuclear Information System (INIS)

Kumakura, M.; Kaetsu, I.

1984-01-01

The effect of pretreatment by radiation and acids—sulfuric, hydrochloric and acetic—on the enzymatic hydrolysis of chaff was studied. The combination of radiation and acids accelerates subsequent crushing and enzymatic hydrolysis. The percentage of fine powder below 115 mesh, after the crushing and the glucose yield on subsequent enzymatic hydrolysis, increased with increasing acid concentration, treatment time and irradiation dose. Radiation and hydrochloric acid pretreatment was the most effective in giving a high glucose conversion yield (about 90%). Irradiation dose, acid concentration, treatment temperature and treatment time were 20 Mrad, 0·5%, 70°C, and 5 h, respectively

Butyric acid fermentation of sodium hydroxide pretreated rice straw with undefined mixed culture.

Science.gov (United States)

Ai, Binling; Li, Jianzheng; Chi, Xue; Meng, Jia; Liu, Chong; Shi, En

2014-05-01

This study describes an alternative mixed culture fermentation technology to anaerobically convert lignocellulosic biomass into butyric acid, a valuable product with wide application, without supplementary cellulolytic enzymes. Rice straw was soaked in 1% NaOH solution to increase digestibility. Among the tested pretreatment conditions, soaking rice straw at 50°C for 72 h removed ~66% of the lignin, but retained ~84% of the cellulose and ~71% of the hemicellulose. By using an undefined cellulose-degrading butyrate-producing microbial community as butyric acid producer in batch fermentation, about 6 g/l of butyric acid was produced from the pretreated rice straw, which accounted for ~76% of the total volatile fatty acids. In the repeated-batch operation, the butyric acid production declined batch by batch, which was most possibly caused by the shift of microbial community structure monitored by denaturing gradient gel electrophoresis. In this study, batch operation was observed to be more suitable for butyric acid production.

Alteration of biomass composition in response to changing substrate particle size and the consequences for enzymatic hydrolysis of corn bran

DEFF Research Database (Denmark)

Agger, Jane; Meyer, Anne S.

2012-01-01

Corn bran is a by-product from corn starch processing. This work examined the effects of changing substrate particle size on enzymatic hydrolysis of both raw and pretreated destarched corn bran. The biomass composition of the corn bran varied between particle size fractions: The largest particles...

Effects of SPORL and dilute acid pretreatment on substrate morphology, cell physical and chemical wall structures, and subsequent enzymatic hydrolysis of lodgepole pine.

Science.gov (United States)

Li, Xinping; Luo, Xiaolin; Li, Kecheng; Zhu, J Y; Fougere, J Dennis; Clarke, Kimberley

2012-11-01

The effects of pretreatment by dilute acid and sulfite pretreatment to overcome recalcitrance of lignocellulose (SPORL) on substrate morphology, cell wall physical and chemical structures, along with the subsequent enzymatic hydrolysis of lodgepole pine substrate were investigated. FE-SEM and TEM images of substrate structural morphological changes showed that SPORL pretreatment resulted in fiber separation, where SPORL high pH (4.2) pretreatment exhibited better fiber separation than SPORL low pH (1.9) pretreatment. Dilute acid pretreatment produced very poor fiber separation, consisting mostly of fiber bundles. The removal of almost all hemicelluloses in the dilute acid pretreated substrate did not overcome recalcitrance to achieve a high cellulose conversion when lignin removal was limited. SPORL high pH pretreatment removed more lignin but less hemicellulose, while SPORL low pH pretreatment removed about the same amount of lignin and hemicelluloses in lodgepole pine substrates when compared with dilute acid pretreatment. Substrates pretreated with either SPORL process had a much higher cellulose conversion than those produced with dilute acid pretreatment. Lignin removal in addition to removal of hemicellulose in SPORL pretreatment plays an important role in improving the cellulose hydrolysis of the substrate.

21 CFR 184.1865 - Corn syrup.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Corn syrup. 184.1865 Section 184.1865 Food and... Substances Affirmed as GRAS § 184.1865 Corn syrup. (a) Corn syrup, commonly called “glucose sirup” or “glucose syrup,” is obtained by partial hydrolysis of corn starch with safe and suitable acids or enzymes...

Comparison of Four Strong Acids on the Precipitation Potential of Gypsum in Brines During Distillation of Pretreated, Augmented Urine

Science.gov (United States)

Muirhead, Dean; Carrier, Christopher

2012-01-01

In this study, three different mineral acids were substituted for sulfuric acid (H2SO4) in the urine stabilizer solution to eliminate the excess of sulfate ions in pretreated urine and assess the impact on maximum water recovery to avoid precipitation of minerals during distillation. The study evaluated replacing 98% sulfuric acid with 85% phosphoric acid (H3PO4), 37% hydrochloric acid (HCl), or 70% nitric acid (HNO3). The effect of lowering the oxidizer concentration in the pretreatment formulation also was studied. This paper summarizes the test results, defines candidate formulations for further study, and specifies the injection masses required to stabilize urine and minimize the risk of mineral precipitation during distillation. In the first test with a brine ersatz acidified with different acids, the solubility of calcium in gypsum saturated solutions was measured. The solubility of gypsum was doubled in the brines acidified with the alternative acids compared to sulfuric acid. In a second series of tests, the alternative acid pretreatment concentrations were effective at preventing precipitation of gypsum and other minerals up to 85% water recovery from 95th-percentile pretreated, augmented urine. Based on test results, phosphoric acid is recommended as the safest alternative to sulfuric acid. It also is recommended that the injected mass concentration of chromium trioxide solution be reduced by 75% to minimize liquid resupply mass by about 50%, reduce toxicity of brines, and reduce the concentration of organic acids in distillate. The new stabilizer solution formulations and required doses to stabilize urine and prevent precipitation of minerals up to 85% water recovery are given. The formulations in this study were tested on a limited number of artificially augmented urine batches collected from employees at the Johnson Space Center (JSC). This study successfully demonstrated that the desired physical and chemical stability of pretreated urine and brines

Formation of trans fatty acids during the frying of chicken fillet in corn oil.

Science.gov (United States)

Yang, Meiyan; Yang, Ying; Nie, Shaoping; Xie, Mingyong; Chen, Feng; Luo, Pengju George

2014-05-01

To assess effects of heated edible oils on intake of trans fatty acids (TFAs); the formation of TFAs in cooking conditions was investigated by a frying system model, in which chicken fillet was fried in a commercial corn oil at 170 °C, for 12 frying cycles. The main TFAs detected in chicken fillet were trans C18:2 fatty acids (FAs) and trans C18:3 FAs, which exhibited no significant differences among the frying cycles. Besides, the content of trans C18:1 FAs were very low in all samples on different frying cycles. The intake of TFAs was estimated to be 0.06 g/100 g when chicken fillet fried in this process was consumed. These results suggest that an ordinary frying process upon a commercial corn oil has little impact on the daily TFAs intake.

Pretreatment of corn stover using wet oxidation to enhance enzymatic digestibility

DEFF Research Database (Denmark)

Varga, E.; Schmidt, A.S.; Reczey, K.

2003-01-01

was about 85%. Decreasing the hydrolysis temperature to 40degreesC increased hydrolysis time from 24 to 72 h. Decreasing the enzyme loading to 5 FPU/g of DM biomass slightly decreased the enzymatic conversion from 83.4 to 71%. Thus, enzyme loading can be reduced without significantly affecting......) was investigated to enhance the enzymatic digestibility of corn stover. Six different combinations of reaction temperature, time, and pH were applied. The best conditions (60 g/L of corn stover, 195degreesC, 15 min, 12 bar O-2, 2 g/L of Na2CO) increased the enzymatic conversion of corn stover four times, compared...... to untreated material. Under these conditions 60% of hemicellulose and 30% of lignin were solubilized, whereas 90% of cellulose remained in the solid fraction. After 24-h hydrolysis at 50degreesC using 25 filter paper units (FPU)/g of drymatter (DM) biomass, the achieved conversion of cellulose to glucose...

Production of l(+)-lactic acid from acid pretreated sugarcane bagasse using Bacillus coagulans DSM2314 in a simultaneous saccharification and fermentation strategy.

Science.gov (United States)

van der Pol, Edwin C; Eggink, Gerrit; Weusthuis, Ruud A

2016-01-01

Sugars derived from lignocellulose-rich sugarcane bagasse can be used as feedstock for production of l(+)-lactic acid, a precursor for renewable bioplastics. In our research, acid-pretreated bagasse was hydrolysed with the enzyme cocktail GC220 and fermented by the moderate thermophilic bacterium Bacillus coagulans DSM2314. Saccharification and fermentation were performed simultaneously (SSF), adding acid-pretreated bagasse either in one batch or in two stages. SSF was performed at low enzyme dosages of 10.5-15.8 FPU/g DW bagasse. The first batch SSF resulted in an average productivity of 0.78 g/l/h, which is not sufficient to compete with lactic acid production processes using high-grade sugars. Addition of 1 g/l furfural to precultures can increase B. coagulans resistance towards by-products present in pretreated lignocellulose. Using furfural-containing precultures, productivity increased to 0.92 g/l/h, with a total lactic acid production of 91.7 g in a 1-l reactor containing 20% W/W DW bagasse. To increase sugar concentrations, bagasse was solubilized with a liquid fraction, obtained directly after acid pretreatment. Solubilizing the bagasse fibres with water increased the average productivity to 1.14 g/l/h, with a total lactic acid production of 84.2 g in a 1-l reactor. Addition of bagasse in two stages reduced viscosity during SSF, resulting in an average productivity in the first 23 h of 2.54 g/l/h, similar to productivities obtained in fermentations using high-grade sugars. Due to fast accumulation of lactic acid, enzyme activity was repressed during two-stage SSF, resulting in a decrease in productivity and a slightly lower total lactic acid production of 75.6 g. In this study, it is shown that an adequate production of lactic acid from lignocellulose was successfully accomplished by a two-stage SSF process, which combines acid-pretreated bagasse, B. coagulans precultivated in the presence of furfural as microorganism, and GC220 as enzyme

Pretreatment Solution for Water Recovery Systems

Science.gov (United States)

Muirhead, Dean (Inventor)

2018-01-01

Chemical pretreatments are used to produce usable water by treating a water source with a chemical pretreatment that contains a hexavalent chromium and an acid to generate a treated water source, wherein the concentration of sulfate compounds in the acid is negligible, and wherein the treated water source remains substantially free of precipitates after the addition of the chemical pretreatment. Other methods include reducing the pH in urine to be distilled for potable water extraction by pretreating the urine before distillation with a pretreatment solution comprising one or more acid sources selected from a group consisting of phosphoric acid, hydrochloric acid, and nitric acid, wherein the urine remains substantially precipitate free after the addition of the pretreatment solution. Another method described comprises a process for reducing precipitation in urine to be processed for water extraction by mixing the urine with a pretreatment solution comprising hexavalent chromium compound and phosphoric acid.

Rheology of dilute acid hydrolyzed corn stover at high solids concentration.

Science.gov (United States)

Ehrhardt, M R; Monz, T O; Root, T W; Connelly, R K; Scott, C T; Klingenberg, D J

2010-02-01

The rheological properties of acid hydrolyzed corn stover at high solids concentration (20-35 wt.%) were investigated using torque rheometry. These materials are yield stress fluids whose rheological properties can be well represented by the Bingham model. Yield stresses increase with increasing solids concentration and decrease with increasing hydrolysis reaction temperature, acid concentration, and rheometer temperature. Plastic viscosities increase with increasing solids concentration and tend to decrease with increasing reaction temperature and acid concentration. The solids concentration dependence of the yield stress is consistent with that reported for other fibrous systems. The changes in yield stress with reaction conditions are consistent with observed changes in particle size. This study illustrates that torque rheometry can be used effectively to measure rheological properties of concentrated biomass.

Optimization of Alkaline and Dilute Acid Pretreatment of Agave Bagasse by Response Surface Methodology

Science.gov (United States)

Ávila-Lara, Abimael I.; Camberos-Flores, Jesus N.; Mendoza-Pérez, Jorge A.; Messina-Fernández, Sarah R.; Saldaña-Duran, Claudia E.; Jimenez-Ruiz, Edgar I.; Sánchez-Herrera, Leticia M.; Pérez-Pimienta, Jose A.

2015-01-01

Utilization of lignocellulosic materials for the production of value-added chemicals or biofuels generally requires a pretreatment process to overcome the recalcitrance of the plant biomass for further enzymatic hydrolysis and fermentation stages. Two of the most employed pretreatment processes are the ones that used dilute acid (DA) and alkaline (AL) catalyst providing specific effects on the physicochemical structure of the biomass, such as high xylan and lignin removal for DA and AL, respectively. Another important effect that need to be studied is the use of a high solids pretreatment (≥15%) since offers many advantaged over lower solids loadings, including increased sugar and ethanol concentrations (in combination with a high solids saccharification), which will be reflected in lower capital costs; however, this data is currently limited. In this study, several variables, such as catalyst loading, retention time, and solids loading, were studied using response surface methodology (RSM) based on a factorial central composite design of DA and AL pretreatment on agave bagasse using a range of solids from 3 to 30% (w/w) to obtain optimal process conditions for each pretreatment. Subsequently enzymatic hydrolysis was performed using Novozymes Cellic CTec2 and HTec2 presented as total reducing sugar (TRS) yield. Pretreated biomass was characterized by wet-chemistry techniques and selected samples were analyzed by calorimetric techniques, and scanning electron/confocal fluorescent microscopy. RSM was also used to optimize the pretreatment conditions for maximum TRS yield. The optimum conditions were determined for AL pretreatment: 1.87% NaOH concentration, 50.3 min and 13.1% solids loading, whereas DA pretreatment: 2.1% acid concentration, 33.8 min and 8.5% solids loading. PMID:26442260

Alkaline peroxide pretreatment of corn stover: effects of biomass, peroxide, and enzyme loading and composition on yields of glucose and xylose

Science.gov (United States)

2011-01-01

monomeric Glc yields of 83% or 95%, respectively. Yields of Glc and Xyl after pretreatment at a low hydrogen peroxide loading (0.125 g H2O2/g biomass) could be improved by extending the pretreatment residence time to 48 h and readjusting the pH to 11.5 every 6 h during the pretreatment. A Glc yield of 77% was obtained using a pretreatment of 15% biomass loading, 0.125 g H2O2/g biomass, and 48 h with pH adjustment, followed by digestion with an optimized commercial enzyme mixture at an enzyme loading of 15 mg protein/g glucan. Conclusions Alkaline peroxide is an effective pretreatment for corn stover. Particular advantages are the use of reagents with low environmental impact and avoidance of special reaction chambers. Reasonable yields of monomeric Glc can be obtained at an H2O2 concentration one-quarter of that used in previous AHP research. Additional improvements in the AHP process, such as peroxide stabilization, peroxide recycling, and improved pH control, could lead to further improvements in AHP pretreatment. PMID:21658263

Bioconversion of dilute-acid pretreated sorghum bagasse to ethanol by Neurospora crassa

Energy Technology Data Exchange (ETDEWEB)

Dogaris, Ioannis; Gkounta, Olga; Mamma, Diomi; Kekos, Dimitris [National Technical Univ. of Athens, Zografou (Greece). Biotechnology Lab.

2012-07-15

Bioethanol production from sweet sorghum bagasse (SB), the lignocellulosic solid residue obtained after extraction of sugars from sorghum stalks, can further improve the energy yield of the crop. The aim of the present work was to evaluate a cost-efficient bioconversion of SB to ethanol at high solids loadings (16 % at pretreatment and 8 % at fermentation), low cellulase activities (1-7 FPU/g SB) and co-fermentation of hexoses and pentoses. The fungus Neurospora crassa DSM 1129 was used, which exhibits both depolymerase and co-fermentative ability, as well as mixed cultures with Saccharomyces cerevisiae 2541. A dilute-acid pretreatment (sulfuric acid 2 g/100 g SB; 210 C; 10 min) was implemented, with high hemicellulose decomposition and low inhibitor formation. The bioconversion efficiency of N. crassa was superior to S. cerevisiae, while their mixed cultures had negative effect on ethanol production. Supplementing the in situ produced N. crassa cellulolytic system (1.0 FPU/g SB) with commercial cellulase and {beta}-glucosidase mixture at low activity (6.0 FPU/g SB) increased ethanol production to 27.6 g/l or 84.7 % of theoretical yield (based on SB cellulose and hemicellulose sugar content). The combined dilute-acid pretreatment and bioconversion led to maximum cellulose and hemicellulose hydrolysis 73.3 % and 89.6 %, respectively. (orig.)

Corn Crisps Enriched in Omega-3 Fatty Acids Sensory Characteristic and its Changes During Storage.

Science.gov (United States)

Rogalski, Mateusz; Nowak, Karolina; Fiedor, Piotr; Szterk, Arkadiusz

Extruded cereal snacks are usually deficient in protein, mineral ingredients, valuable fatty acids. With the rise of health awareness among consumers, food manufacturers and scientists are pressed to take measures in order to develop new functional/health-beneficial foods. The aim of this work was to manufacture extruded crisps enriched with α-linolenic acid (obtained from linseed oil) and to observe whether storage of the product for the period of 6 months would cause its disqualification, primarily due to its sensory properties and secondarily due to its chemical properties. The research demonstrated that the addition of linseed oil to corn crisps at the amount of 5 % enables to obtain functional corn crisps containing over 2 g of ALA in a portion of 100 g even after 6 months of storage at room temperature. ALA-enriched crisps maintain the original sensory profile after 6 months of storage and their sensory profile is similar to the profile of crisps without the addition of linseed oil if they are packed in barrier packaging filled 100 % with argon. Therefore, they may be a healthier alternative to typical corn crisps.

Brewer’s Spent Grain Valorization Using Phosphoric Acid Pretreatment for Second Generation Bioethanol Production

DEFF Research Database (Denmark)

Romero, I.; Ruiz, E.; Cara, C.

the effect of phosphoric acid concentration (2-6% w/v) and pretreatment temperature (140-180ºC). The influence of these factors on the hemicellulosic sugar solubilisation and the subsequent enzymatic hydrolysis was evaluated. Optimal pretreatment conditions were determined by maximizing both...... hemicellulosic sugar recovery in liquids and enzymatic hydrolysis yield....

21 CFR 184.1857 - Corn sugar.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Corn sugar. 184.1857 Section 184.1857 Food and... Substances Affirmed as GRAS § 184.1857 Corn sugar. (a) Corn sugar (C6H12O6, CAS Reg. No. 50-99-7), commonly... monohydrate form and is produced by the complete hydrolysis of corn starch with safe and suitable acids or...

Microwave assisted acid and alkali pretreatment of Miscanthus biomass for biorefineries

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Zongyuan Zhu

2015-10-01

Full Text Available Miscanthus is a major bioenergy crop in Europe and a potential feedstock for second generation biofuels. Thermochemical pretreatment is a significant step in the process of converting lignocellulosic biomass into fermentable sugars. In this work, microwave energy was applied to facilitate NaOH and H2SO4 pretreatments of Miscanthus. This was carried out at 180 ℃ in a monomode microwave cavity at 300 W. Our results show that H2SO4 pretreatment contributes to the breakdown of hemicelluloses and cellulose, leading to a high glucose yield. The maximum sugar yield from available carbohydrates during pretreatment is 75.3% (0.2 M H2SO4 20 Min, and glucose yield is 46.7% under these conditions. NaOH and water pretreatments tend to break down only hemicellulose in preference to cellulose, contributing to high xylose yield. Compared to conventional heating NaOH/H2SO4 pretreatment, 12 times higher sugar yield was obtained by using microwave assisted pretreatment within half the time. NaOH pretreatments lead to a significantly enhanced digestibility of the residue, because the effective removal of lignin and hemicellulose makes cellulose fibres more accessible to cellulases. Morphological study of biomass shows that the tightly packed fibres in the Miscanthus were dismantled and exposed under NaOH condition. We studied sugar degradation under microwave assisted H2SO4 conditions. The results shows that 6-8% biomass was converted into levulinic acid (LA during pretreatment, showing the possibility of using microwave technology to produce LA from biomass. The outcome of this work shows great potential for using microwave in the thermo-chemical pretreatment for biomass and also selective production of LA from biomass.

EFEK PERLAKUAN KIMIAWI DAN HIDROTERMOLISIS PADA BIOMAS TANAMAN JAGUNG (Zea mays L. SEBAGAI SUBSTRAT PRODUKSI BIOETANOL The Effects of Chemical and Hydrothermolysis Pretreatment of Corn Stover Biomass (Zea mays L. as The Bioethanol Production Substrate

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Wagiman Wagiman

2012-05-01

Full Text Available The purpose of this research was to obtain a fermentation substrate with a high content of cellulose and hemicellulose, as well as to decrease the cellulose cystalinity. Dried corn stover was crushed to pass 40 mesh, added by Ca(OH and water, then heated at a certain time. The experimental design was prepared using a four-factor central composite design (CCD. The results of the chemical pretreatment were treated using hydrothermolysis methods for enhancing the lignin removal and decreasing cellulose crystalinity. The suitable process condition for chemical pretreatment was achieved at the loading of 0.075 g Ca(OH /g corn stover and 6.25 ml water/g corn stover, temperature 74.6 OC at 2 hours. After hydrothermolysis, cellulose and hemicellulose were dissolved at the percentages of 52.40 % and 31.84 % respectively, while the fraction of solid substrate had a composition of cellulose of 42.68 % and hemicellulosa of 34.68 %. The crystalinity of cellulose from the leaves, cobs, and cornhusk decreased significantly. The SEM results indicated that the surface of cell wall of corn stover had been perforated by these pretreatment processes. These pores might increase the enzymatic hydrolysis of the lignocellulosic corn stover. ABSTRAK Tujuan penelitian adalah mendapatkan substrat fermentasi dengan kandungan selulosa dan hemiselulosa tinggi serta menurunkan kristalinitas komponen selulosa. Limbah tanaman jagung yang sudah kering dihancurkan hingga lolos 40 mesh, ditambah Ca(OH dan air, kemudian dipanaskan pada suhu dan waktu tertentu. Rancangan percobaan disusun dengan menggunakan central composite design (CCD dengan empat faktor. Hasil terbaik tahap ini diberi perlakuan hidrotermolisis untuk meningkatkan penyisihan komponen lignin dan menurunkan kristalinitas selulosa. Hasil pene­ litian menunjukkan bahwa kondisi proses terbaik adalah penambahan 0,075 g Ca(OH /g biomas dan 6,25 ml air/g biomas, suhu pemanasan 74,6 OC dengan waktu 2 jam

Effect of EDTA and phosphoric Acid pretreatment on the bonding effectiveness of self-etch adhesives to ground enamel.

Science.gov (United States)

Ibrahim, Ihab M; Elkassas, Dina W; Yousry, Mai M

2010-10-01

This in vitro study determined the effect of enamel pretreatment with phosphoric acid and ethylenediaminetetraacetic acid (EDTA) on the bond strength of strong, intermediary strong, and mild self-etching adhesive systems. Ninety sound human premolars were used. Resin composite cylinders were bonded to flat ground enamel surfaces using three self-etching adhesive systems: strong Adper Prompt L-Pop (pH=0.9-1.0), intermediary strong AdheSE (pH=1.6-1.7), and mild Frog (pH=2). Adhesive systems were applied either according to manufacturer instructions (control) or after pretreatment with either phosphoric acid or EDTA (n=10). After 24 hours, shear bond strength was tested using a universal testing machine at a cross-head speed of 0.5 mm/minute. Ultra-morphological characterization of the surface topography and resin/enamel interfaces as well as representative fractured enamel specimens were examined using scanning electron microscopy (SEM). Neither surface pretreatment statistically increased the mean shear bond strength values of either the strong or the intermediary strong self-etching adhesive systems. However, phosphoric acid pretreatment significantly increased the mean shear bond strength values of the mild self-etching adhesive system. SEM examination of enamel surface topography showed that phosphoric acid pretreatment deepened the same etching pattern of the strong and intermediary strong adhesive systems but converted the irregular etching pattern of the mild self-etching adhesive system to a regular etching pattern. SEM examination of the resin/enamel interface revealed that deepening of the etching pattern was consistent with increase in the length of resin tags. EDTA pretreatment had a negligible effect on ultra-morphological features. Use of phosphoric acid pretreatment can be beneficial with mild self-etching adhesive systems for bonding to enamel.

Combined alkali and acid pretreatment of spent mushroom substrate for reducing sugar and biofertilizer production.

Science.gov (United States)

Zhu, Hong-Ji; Liu, Jia-Heng; Sun, Li-Fan; Hu, Zong-Fu; Qiao, Jian-Jun

2013-05-01

Spent mushroom substrate (SMS) was pretreated with alkaline reagents including potassium hydroxide, lime and ammonia to enhance enzymatic saccharification. Under the best pretreatment conditions (1M KOH, 80 °C, 90 min; 1M lime, 80 °C, 120 min; 10 M ammonia, 70 °C, 120 min), the total reducing sugar (TRS) yield reached 258.6, 204.2 and 251.2 mg/g raw SMS, which were respectively 6.15, 4.86, and 5.98 times of untreated SMS. The effects of pretreatment by above alkaline reagents and sulfuric acid on the composition and structure of SMS were evaluated to provide comparative performance data. A new process, combined alkali and acid (CAA) pretreatment followed by enzymatic hydrolysis, was innovatively proposed to improve the cost-effectiveness and avoid environmental problems. The SMS residue after CAA pretreatment-enzymatic hydrolysis process was converted to biofertilizer with Pichia farinose FL7 and a cell density of 3.0×10(8) cfu/g in biomass was attained. Copyright © 2013 Elsevier Ltd. All rights reserved.

Behavior of /sup 15/N-labelled amino acids in germinated corn

Energy Technology Data Exchange (ETDEWEB)

Samukawa, K; Yamaguchi, M [Osaka Prefectural Univ., Sakai (Japan). Coll. of Agriculture

1979-06-01

By investigating the rise and fall of /sup 15/N-labelled amino acids in germinated corns, the behavior of amino radicals in free amino acids, the influence of the hydrolysis products of stored proteins on free amino acids and the change from heterotrophy to autotrophy of seeds were clarified. The amount of amino acid production depending on external nitrogen was very small in the early period of germination. /sup 15/N incorporation into proline was not observed in the early period of germination, which suggested that the proline may be nitrogen-storing source. Most of the amino-state nitrogen of asparagine accumulated at the time of germination was internal nitrogen, and this fact suggested that aspartic acid serve as the acceptor of ammonia produced in the early stage of germination. /sup 15/N content increased significantly on 9 th day after germination, and decreased on 12 th day. These facts prove that there are always active decomposition and production of protein in plant body.

The use of raw and acid-pretreated bivalve mollusk shells to remove metals from aqueous solutions

International Nuclear Information System (INIS)

Liu Yang; Sun Changbin; Xu Jin; Li Youzhi

2009-01-01

Heavy metal removal from industrial wastewater is not only to protect living organisms in the environment but also to conserve resources such as metals and water by enabling their reuse. To overcome the disadvantage of high cost and secondary pollution by the conventional physico-chemical treatment techniques, environmentally benign and low-cost adsorbents are in demand. In this study, the use of raw and acid-pretreated bivalve mollusk shells (BMSs) to remove metals from aqueous solutions with single or mixed metal was evaluated at different BMSs doses, pH and temperatures in batch shaking experiments in laboratory conditions. When the BMSs were used to treat CuSO 4 .5H 2 O solution, the copper sorption capacities of the raw and acid-pretreated BMSs were approximately 38.93 mg/g and 138.95 mg/g, respectively. The copper removal efficiency (CRE) of the raw BMSs became greatly enhanced with increasing initial pH, reaching 99.51% at the initial pH 5. Conversely, the CRE of the acid-pretreated BMSs was maintained at 99.48-99.52% throughout the pH range of 1-5. Furthermore, the CRE values of the raw and acid-pretreated BMSs were not greatly changed when the temperature was varied from 15 deg. C to 40 deg. C. In addition, the CRE value of the raw BMSs was maintained for 12 cycles of sorption-desorption with a CRE of 98.4% being observed in the final cycle. Finally, when the BMSs were used to treat electroplating wastewater, the removal efficiencies (REs) of the raw BMSs were 99.97%, 98.99% and 87% for Fe, Zn and Cu, respectively, whereas the REs of the acid-pretreated BMSs were 99.98%, 99.43% and 92.13%, respectively. Ion exchange experiments revealed that one of mechanisms for metal sorption by the BMSs from aqueous solution is related to ion exchange, especially between the metal ions in the treated solution and Ca 2+ from BMSs. Infrared absorbance spectra analysis indicated that the acid pretreatment led to occurrence of the groups (i.e. -OH, -NH, C=O and S=O) of

The use of raw and acid-pretreated bivalve mollusk shells to remove metals from aqueous solutions.

Science.gov (United States)

Liu, Yang; Sun, Changbin; Xu, Jin; Li, Youzhi

2009-08-30

Heavy metal removal from industrial wastewater is not only to protect living organisms in the environment but also to conserve resources such as metals and water by enabling their reuse. To overcome the disadvantage of high cost and secondary pollution by the conventional physico-chemical treatment techniques, environmentally benign and low-cost adsorbents are in demand. In this study, the use of raw and acid-pretreated bivalve mollusk shells (BMSs) to remove metals from aqueous solutions with single or mixed metal was evaluated at different BMSs doses, pH and temperatures in batch shaking experiments in laboratory conditions. When the BMSs were used to treat CuSO(4)x5H(2)O solution, the copper sorption capacities of the raw and acid-pretreated BMSs were approximately 38.93 mg/g and 138.95 mg/g, respectively. The copper removal efficiency (CRE) of the raw BMSs became greatly enhanced with increasing initial pH, reaching 99.51% at the initial pH 5. Conversely, the CRE of the acid-pretreated BMSs was maintained at 99.48-99.52% throughout the pH range of 1-5. Furthermore, the CRE values of the raw and acid-pretreated BMSs were not greatly changed when the temperature was varied from 15 degrees C to 40 degrees C. In addition, the CRE value of the raw BMSs was maintained for 12 cycles of sorption-desorption with a CRE of 98.4% being observed in the final cycle. Finally, when the BMSs were used to treat electroplating wastewater, the removal efficiencies (REs) of the raw BMSs were 99.97%, 98.99% and 87% for Fe, Zn and Cu, respectively, whereas the REs of the acid-pretreated BMSs were 99.98%, 99.43% and 92.13%, respectively. Ion exchange experiments revealed that one of mechanisms for metal sorption by the BMSs from aqueous solution is related to ion exchange, especially between the metal ions in the treated solution and Ca(2+) from BMSs. Infrared absorbance spectra analysis indicated that the acid pretreatment led to occurrence of the groups (i.e. -OH, -NH, C=O and S

Development of rapid bioconversion with integrated recycle technology for ethanol production from extractive ammonia pretreated corn stover.

Science.gov (United States)

Jin, Mingjie; Liu, Yanping; da Costa Sousa, Leonardo; Dale, Bruce E; Balan, Venkatesh

2017-08-01

High enzyme loading and low productivity are two major issues impeding low cost ethanol production from lignocellulosic biomass. This work applied rapid bioconversion with integrated recycle technology (RaBIT) and extractive ammonia (EA) pretreatment for conversion of corn stover (CS) to ethanol at high solids loading. Enzymes were recycled via recycling unhydrolyzed solids. Enzymatic hydrolysis with recycled enzymes and fermentation with recycled yeast cells were studied. Both enzymatic hydrolysis time and fermentation time were shortened to 24 h. Ethanol productivity was enhanced by two times and enzyme loading was reduced by 30%. Glucan and xylan conversions reached as high as 98% with an enzyme loading of as low as 8.4 mg protein per g glucan. The overall ethanol yield was 227 g ethanol/kg EA-CS (191 g ethanol/kg untreated CS). Biotechnol. Bioeng. 2017;114: 1713-1720. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

The roles of xylan and lignin in oxalic acid pretreated corncob during separate enzymatic hydrolysis and ethanol fermentation

Science.gov (United States)

Jae-Won Lee; Rita C.L.B. Rodrigues; Hyun Joo Kim; In-Gyu Choi; Thomas W. Jeffries

2010-01-01

High yields of hemicellulosic and cellulosic sugars are critical in obtaining economical conversion of agricultural residues to ethanol. To optimize pretreatment conditions, we evaluated oxalic acid loading rates, treatment temperatures and times in a 23 full factorial design. Response-surface analysis revealed an optimal oxalic acid pretreatment...

Revealing the Molecular Structural Transformation of Hardwood and Softwood in Dilute Acid Flowthrough Pretreatment

Energy Technology Data Exchange (ETDEWEB)

Zhang, Libing; Pu, Yunqiao; Cort, John R.; Ragauskas, Arthur J.; Yang, Bin

2016-12-05

To better understand the intrinsic recalcitrance of lignocellulosic biomass, the main hurdle to its efficient deconstruction, the effects of dilute acid flowthrough pretreatment on the dissolution chemistry of hemicellulose, cellulose, and lignin for both hardwood (e.g. poplar wood) and softwood (e.g. lodgepole pine wood) were investigated at temperatures of 200 °C to 270 °C and a flow rate of 25 mL/minute with 0.05% (w/w) H2SO4. Results suggested that the softwood cellulose was more readily to be degraded into monomeric sugars than that of hardwood under same pretreatment conditions. However, while the hardwood lignin was completely removed into hydrolysate, ~30% of the softwood lignin remained as solid residues under identical conditions, which was plausibly caused by vigorous C5-active recondensation reactions (C-C5). Unique molecular structural features that pronounced the specific recalcitrance of hardwood and softwood to dilute acid pretreatment were identified for the first time in this study, providing important insights to establish the effective biomass pretreatment.

An Efficient Process for Pretreatment of Lignocelluloses in Functional Ionic Liquids

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Shi-Jia Dong

2015-01-01

Full Text Available Background and Aims. The complex structure of the lignocelluloses is the main obstacle in the conversion of lignocellulosic biomass into valuable products. Ionic liquids provide the opportunities for their efficient pretreatment for biomass. Therefore, in this work, pretreatment of corn stalk was carried out in ultrasonic-assisted ionic liquid including 1-butyl-3-methylimidazolium chloride [BMIM]Cl, 1-H-3-methylimidazolium chloride [HMIM]Cl, and 1-(1-propylsulfonic-3-imidazolium chloride [HSO3-pMIM]Cl at 70°C for 2 h. We compared the pretreatments by ionic liquid with and without the addition of deionized water. Fourier transform infrared spectroscopy (FTIR and scanning electron microscopy (SEM were employed to analyze the chemical characteristics of regenerated cellulose-rich materials. Results. [HMIM]Cl and [HSO3-pMIM]Cl were effective in lignin extraction to obtain cellulose-rich materials. FTIR analysis and SEM analysis indicated the effective lignin removal and the reduced crystallinity of cellulose-rich materials. Enzymatic hydrolysis of cellulose-rich materials was performed efficiently. High yields of reducing sugar and glucose were obtained when the corn stalk was pretreated by [HMIM]Cl and [HSO3-pMIM]Cl. Conclusions. Ionic liquids provided the ideal environment for lignin extraction and enzymatic hydrolysis of corn stalk and [HMIM]Cl and [HSO3-pMIM]Cl proved the most efficient ionic liquids. This simple and environmentally acceptable method has a great potential for the preparation of bioethanol for industrial production.

Pretreatment of Sugar Beet Pulp with Dilute Sulfurous Acid is Effective for Multipurpose Usage of Carbohydrates.

Science.gov (United States)

Kharina, M; Emelyanov, V; Mokshina, N; Ibragimova, N; Gorshkova, T

2016-05-01

Sulfurous acid was used for pretreatment of sugar beet pulp (SBP) in order to achieve high efficiency of both extraction of carbohydrates and subsequent enzymatic hydrolysis of the remaining solids. The main advantage of sulfurous acid usage as pretreatment agent is the possibility of its regeneration. Application of sulfurous acid as hydrolyzing agent in relatively low concentrations (0.6-1.0 %) during a short period of time (10-20 min) and low solid to liquid ratio (1:3, 1:6) allowed effective extraction of carbohydrates from SBP and provided positive effect on subsequent enzymatic hydrolysis. The highest obtained concentration of reducing substances (RS) in hydrolysates was 8.5 %; up to 33.6 % of all carbohydrates present in SBP could be extracted. The major obtained monosaccharides were arabinose and glucose (9.4 and 7.3 g/l, respectively). Pretreatment of SBP with sulfurous acid increased 4.6 times the yield of glucose during subsequent enzymatic hydrolysis of remaining solids with cellulase cocktail, as compared to the untreated SBP. Total yield of glucose during SBP pretreatment and subsequent enzymatic hydrolysis amounted to 89.4 % of the theoretical yield. The approach can be applied directly to the wet SBP. Hydrolysis of sugar beet pulp with sulfurous acid is recommended for obtaining of individual monosaccharides, as well as nutritional media.

Comparison of aqueous ammonia and dilute acid pretreatment of bamboo fractions: Structure properties and enzymatic hydrolysis.

Science.gov (United States)

Xin, Donglin; Yang, Zhong; Liu, Feng; Xu, Xueru; Zhang, Junhua

2015-01-01

The effect of two pretreatments methods, aqueous ammonia (SAA) and dilute acid (DA), on the chemical compositions, cellulose crystallinity, morphologic change, and enzymatic hydrolysis of bamboo fractions (bamboo yellow, timber, green, and knot) was compared. Bamboo fractions with SAA pretreatment had better hydrolysability than those with DA pretreatment. High crystallinity index resulted in low hydrolysis yield in the conversion of SAA pretreated bamboo fractions, not DA pretreated fractions. The increase of cellulase loading had modestly positive effect in the hydrolysis of both SAA and DA pretreated bamboo fractions, while supplement of xylanase significantly increased the hydrolysis of the pretreated bamboo fractions, especially after SAA pretreatment. The results indicated that SAA pretreatment was more effective than DA pretreatment in conversion of bamboo fractions, and supplementation of xylanase was necessary in effective conversion of the SAA pretreated fractions into fermentable sugars. Copyright © 2014 Elsevier Ltd. All rights reserved.

Alkaline peroxide pretreatment of corn stover: effects of biomass, peroxide, and enzyme loading and composition on yields of glucose and xylose

Directory of Open Access Journals (Sweden)

Hodge David B

2011-06-01

/g glucan gave monomeric Glc yields of 83% or 95%, respectively. Yields of Glc and Xyl after pretreatment at a low hydrogen peroxide loading (0.125 g H2O2/g biomass could be improved by extending the pretreatment residence time to 48 h and readjusting the pH to 11.5 every 6 h during the pretreatment. A Glc yield of 77% was obtained using a pretreatment of 15% biomass loading, 0.125 g H2O2/g biomass, and 48 h with pH adjustment, followed by digestion with an optimized commercial enzyme mixture at an enzyme loading of 15 mg protein/g glucan. Conclusions Alkaline peroxide is an effective pretreatment for corn stover. Particular advantages are the use of reagents with low environmental impact and avoidance of special reaction chambers. Reasonable yields of monomeric Glc can be obtained at an H2O2 concentration one-quarter of that used in previous AHP research. Additional improvements in the AHP process, such as peroxide stabilization, peroxide recycling, and improved pH control, could lead to further improvements in AHP pretreatment.

Changes in lignocellulosic supramolecular and ultrastructure during dilute acid pretreatment of Populus and switchgrass

International Nuclear Information System (INIS)

Foston, Marcus; Ragauskas, Art J.

2010-01-01

Dilute acid pretreatment (DAP) is commonly employed prior to enzymatic deconstruction of cellulose to increase overall sugar and subsequent ethanol yields from downstream bioconversion processes. Typically optimization of pretreatment is evaluated by determining hemicellulose removal, subsequent reactivity towards enzymatic deconstruction, and recoverable polysaccharide yields. In this study, the affect of DAP on the supramolecular and ultrastructure of lignocellulosic biomass was evaluated. A series of dilute acidic pretreatments, employing ∼0.10-0.20 mol/m 3 H 2 SO 4 at ∼160-180 o C, for varying residence times were conducted on both Populus and switchgrass samples. The untreated and pretreated biomass samples were characterized by carbohydrate and lignin analysis, gel permeation chromatography (GPC) and 13 C cross polarization magic angle spinning (CPMAS) NMR spectroscopy. GPC analysis shows a reduction in the molecular weight of cellulose and change in its polydispersity index (PDI) with increasing residence time, indicating that pretreatment is actually degrading the cellulose chains. 13 C CPMAS and non-linear line-fitting of the C 4 region in the carbon spectrum of the isolated cellulose not only showed that the crystallinity index increases with residence time, but that the lateral fibril dimension (LFD) and lateral fibril aggregate dimension (LFAD) increase as well.

Bioconversion of dilute-acid pretreated sorghum bagasse to ethanol by Neurospora crassa.

Science.gov (United States)

Dogaris, Ioannis; Gkounta, Olga; Mamma, Diomi; Kekos, Dimitris

2012-07-01

Bioethanol production from sweet sorghum bagasse (SB), the lignocellulosic solid residue obtained after extraction of sugars from sorghum stalks, can further improve the energy yield of the crop. The aim of the present work was to evaluate a cost-efficient bioconversion of SB to ethanol at high solids loadings (16 % at pretreatment and 8 % at fermentation), low cellulase activities (1-7 FPU/g SB) and co-fermentation of hexoses and pentoses. The fungus Neurospora crassa DSM 1129 was used, which exhibits both depolymerase and co-fermentative ability, as well as mixed cultures with Saccharomyces cerevisiae 2541. A dilute-acid pretreatment (sulfuric acid 2 g/100 g SB; 210 °C; 10 min) was implemented, with high hemicellulose decomposition and low inhibitor formation. The bioconversion efficiency of N. crassa was superior to S. cerevisiae, while their mixed cultures had negative effect on ethanol production. Supplementing the in situ produced N. crassa cellulolytic system (1.0 FPU/g SB) with commercial cellulase and β-glucosidase mixture at low activity (6.0 FPU/g SB) increased ethanol production to 27.6 g/l or 84.7 % of theoretical yield (based on SB cellulose and hemicellulose sugar content). The combined dilute-acid pretreatment and bioconversion led to maximum cellulose and hemicellulose hydrolysis 73.3 % and 89.6 %, respectively.

Pretreatment with ascorbic acid prevents lethal gastrointestinal syndrome in mice receiving a massive amount of radiation

International Nuclear Information System (INIS)

Yamamoto, Tetsuo; Kinoshita, Manabu; Shinomiya, Nariyoshi; Hiroi, Sadayuki; Sugasawa, Hidekazu; Majima, Takashi; Seki, Shuhji; Matsushita, Yoshitaro; Saitoh, Daizoh

2010-01-01

While bone marrow or stem cell transplantation can rescue bone marrow aplasia in patients accidentally exposed to a lethal radiation dose, radiation-induced irreversible gastrointestinal damage (GI syndrome) is fatal. We investigated the effects of ascorbic acid on radiation-induced GI syndrome in mice. Ascorbic acid (150 mg/kg/day) was orally administered to mice for 3 days, and then the mice underwent whole body irradiation (WBI). Bone marrow transplantation (BMT) 24 h after irradiation rescued mice receiving a WBI dose of less than 12 Gy. No mice receiving 14 Gy-WBI survived, because of radiation-induced GI syndrome, even if they received BMT. However, pretreatment with ascorbic acid significantly suppressed radiation-induced DNA damage in the crypt cells and prevented denudation of intestinal mucosa; therefore, ascorbic acid in combination with BMT rescued mice after 14 Gy-WBI. DNA microarray analysis demonstrated that irradiation up-regulated expressions of apoptosis-related genes in the small intestine, including those related to the caspase-9-mediated intrinsic pathway as well as the caspase-8-mediated extrinsic pathway, and down-regulated expressions of these genes in ascorbic acid-pretreated mice. Thus, pretreatment with ascorbic acid may effectively prevent radiation-induced GI syndrome. (author)

Succinic acid production by Actinobacillus succinogenes using hydrolysates of spent yeast cells and corn fiber.

Science.gov (United States)

Chen, Ke-Quan; Li, Jian; Ma, Jiang-Feng; Jiang, Min; Wei, Ping; Liu, Zhong-Min; Ying, Han-Jie

2011-01-01

The enzymatic hydrolysate of spent yeast cells was evaluated as a nitrogen source for succinic acid production by Actinobacillus succinogenes NJ113, using corn fiber hydrolysate as a carbon source. When spent yeast cell hydrolysate was used directly as a nitrogen source, a maximum succinic acid concentration of 35.5 g/l was obtained from a glucose concentration of 50 g/l, with a glucose utilization of 95.2%. Supplementation with individual vitamins showed that biotin was the most likely factor to be limiting for succinic acid production with spent yeast cell hydrolysate. After supplementing spent yeast cell hydrolysate and 90 g/l of glucose with 150 μg/l of biotin, cell growth increased 32.5%, glucose utilization increased 37.6%, and succinic acid concentration was enhanced 49.0%. As a result, when biotin-supplemented spent yeast cell hydrolysate was used with corn fiber hydrolysate, a succinic acid yield of 67.7% was obtained from 70.3 g/l of total sugar concentration, with a productivity of 0.63 g/(l h). Our results suggest that biotin-supplemented spent yeast cell hydrolysate may be an alternative nitrogen source for the efficient production of succinic acid by A. succinogenes NJ113, using renewable resources. Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.

Pretreatment of phosphoric acid of Annaba

International Nuclear Information System (INIS)

Kada, R.

1990-03-01

The most important step in the process of uranium recovery from phosphoric acid is the pretreatment operation. In this study, the adsorption of organic matters on activated carbon was carried out in a batch process and in a fixed bed column. First, the chemical and physical characterization of phosphoric acid, activated carbon and gypsum were performed. In addition, the organic matters were qualitatively analysed and a new and original quantitative method was experimented. Next, the various operating parameters such as agitation speed, granulometry, temperature, solid/liquid ratio, initial concentration, acid flowrate, and bed height were optimized. The experimental equilibrium isotherm was compared to the Langmuir, Freundlich, and Redlich-Peterson theoretical isotherms. It was noticed that the three models did not fit the experimental isotherm in the total concentration range. Thus, an original bilinear model was proposed. The influence of the operating conditions on the adsorption kinetics was also investigated. As a result of that, a new mathematical model was proposed to determine both the liquid and solid phases mass transfer and the solid phase diffusion coefficient. Finally, adsorption of organic matters on a fixed bed process allowed computation of the number of transfer units (NTU), the height of adsorption zone and the degree of saturation of activated carbon

Effect of total solid content and pretreatment on the production of lactic acid from mixed culture dark fermentation of food waste.

Science.gov (United States)

Yousuf, Ahasa; Bastidas-Oyanedel, Juan-Rodrigo; Schmidt, Jens Ejbye

2018-04-28

Food waste landfilling causes environmental degradation, and this work assesses a sustainable food valorization technique. In this study, food waste is converted into lactic acid in a batch assembly by dark fermentation without pH control and without the addition of external inoculum at 37 °C. The effect of total solid (TS), enzymatic and aeration pretreatment was investigated on liquid products concentration and product yield. The maximum possible TS content was 34% of enzymatic pretreated waste, and showed the highest lactic acid concentration of 52 g/L, with a lactic acid selectivity of 0.6 g lactic /g totalacids . The results indicated that aeration pretreatment does not significantly improve product concentration or yield. Non-pretreated waste in a 29% TS system showed a lactic acid concentration of 31 g/L. The results showed that enzymatic pretreated waste at TS of 34% results in the highest production of lactic acid. Copyright © 2018 Elsevier Ltd. All rights reserved.

Pretreatment with oleic acid accelerates the entrance into the mitotic cycle of EGF-stimulated fibroblasts.

Science.gov (United States)

Zugaza, J L; Casabiell, X A; Bokser, L; Eiras, A; Beiras, A; Casanueva, F F

1995-07-01

We have previously demonstrated that pretreatment of several cell lines with cis-unsaturated fatty acids, like oleic acid, blocks epidermal growth factor (EGF)-induced early ionic signals, and in particular the [Ca2+]i rise. In the present work we show that this blockade does not alter EGF-stimulated cellular proliferation evaluated by direct cell counting, but induces a powerful enhancement in the pulsed thymidine incorporation assay. The lack of effect of oleic acid on EGF-stimulated cellular proliferation was confirmed by repeated cell counts, cumulative thymidine incorporation, and protein synthesis, but a clear synergistic effect between oleic acid and EGF was again obtained by means of time course experiments with pulsed thymidine. Combined flow cytometry analysis and cell counts at earlier times in EGF-stimulated cells showed that oleic acids accelerates the entrance of cells into the replicative cycle leading to an earlier cell division. Afterward, these oleic acid-pretreated cells became delayed by an unknown compensatory mechanism in such a way that at 48 h post-EGF, the cell count in control and oleic acid-pretreated cells was equal. In conclusion (a) oleic acid accelerates or enhances the EGF mitogenic action and (b) in the long term cells compensate the initial perturbation with respect to untreated cells. As a side observation, the widely employed pulsed thymidine incorporation method as a measure of cell division could be extremely misleading unless experimental conditions are well controlled.

Transport of indoleacetic acid in intact corn coleoptiles

International Nuclear Information System (INIS)

Parker, K.E.; Briggs, W.R.

1990-01-01

We have characterized the transport of [ 3 H]indoleacetic acid (IAA) in intact corn (Zea mays L.) coleoptiles. We have used a wide range of concentrations of added IAA (28 femtomoles to 100 picomoles taken up over 60 minutes). The shape of the transport curve varies with the concentration of added IAA, although the rate of movement of the observed front of tracer is invariant with concentration. At the lowest concentration of tracer used, the labeled IAA in the transport stream is not detectably metabolized or immobilized, curvature does not develop as a result of tracer application, and normal phototropic and gravitropic responsiveness are not affected. Therefore we believe we are observing the transport of true tracer quantities of labeled auxin at this lowest concentration

Reactivities of acid and/or tetralin pretreated Wandoan coal for a Curie point flash pyrolysis; Sanzen shori, tetralin yobaimae shori Wandoan tan no kyusoku netsubunkai

Energy Technology Data Exchange (ETDEWEB)

Kishino, M.; Sakanishi, K.; Korai, Y.; Mochida, I. [Kyushu University, Fukuoka (Japan). Institute of Advanced Material Study

1996-10-28

Discussions were given on effects of acid pretreatment and tetralin swelling in Wandoan coal on a Curie point flash pyrolysis (which used a Curie point pyrolyzer). Residue yield loss effects were obtained at 3.9% in hydrochloric acid pretreatment, and 6.2% in acetic acid pretreatment. The effects of tetralin swelling pretreatment were compared in the similar manner in terms of the residue yield loss. The effects were 4.0% in untreated coal, 2.0% in the hydrochloric acid pretreatment, and 0.6% in the acetic acid pretreatment. It is thought that components that can be activated by acetic acid have already been activated, but the remaining components would not be activated by tetralin. Average microporosity (area) in the remaining particle as a whole shows very little difference both in acetic acid pretreated coal and untreated coal. However, with the acetic acid pretreatment, pores smaller than 4{mu}m{sup 2} disappeared, and pores as large as 205 to 411{mu}m{sup 2} increased largely. This phenomenon was observed as an increase in foaming degree under microscopic observation, even if the average microporosity remains equal. Thermoplasticity of the coal increased, and so did volatilization reactivity as a result of the acetic acid pretreatment, resulting in appearance of a large number of large pores. 6 refs., 2 figs., 2 tabs.

Dilute-acid pretreatment of barley straw for biological hydrogen production using Caldicellulosiruptor saccharolyticus

NARCIS (Netherlands)

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

2012-01-01

The main objective of this study was to use the fermentability test to investigate the feasibility of applying various dilute acids in the pretreatment of barley straw for biological hydrogen production. At a fixed acid loading of 1% (w/w dry matter) 28-32% of barley straw was converted to soluble

Improving production of volatile fatty acids from food waste fermentation by hydrothermal pretreatment.

Science.gov (United States)

Yin, Jun; Wang, Kun; Yang, Yuqiang; Shen, Dongsheng; Wang, Meizhen; Mo, Han

2014-11-01

Food waste (FW) was pretreated by a hydrothermal method and then fermented for volatile fatty acid (VFAs) production. The soluble substance in FW increased after hydrothermal pretreatment (⩽200 °C). Higher hydrothermal temperature would lead to mineralization of the organic compounds. The optimal temperature for organic dissolution was 180 °C, at which FW dissolved 42.5% more soluble chemical oxygen demand than the control. VFA production from pretreated FW fermentation was significantly enhanced compared with the control. The optimal hydrothermal temperature was 160 °C with a VFA yield of 0.908 g/g VSremoval. Butyrate and acetate were the prevalent VFAs followed by propionate and valerate. FW fermentation was inhibited after 200 °C pretreatment. The VFAs were extracted from the fermentation broth by liquid-liquid extraction. The VFA recovery was 50-70%. Thus, 0.294-0.411 g VFAs could be obtained per gram of hydrothermally pretreated FW (in dry weight) by this method. Copyright © 2014 Elsevier Ltd. All rights reserved.

Impact of Pretreatment Technologies on Saccharification and Isopentenol Fermentation of Mixed Lignocellulosic Feedstocks

Energy Technology Data Exchange (ETDEWEB)

Shi, Jian; George, Kevin W.; Sun, Ning; He, Wei; Li, Chenlin; Stavila, Vitalie; Keasling, Jay D.; Simmons, Blake A.; Lee, Taek Soon; Singh, Seema

2015-02-28

In order to enable the large-scale production of biofuels or chemicals from lignocellulosic biomass, a consistent and affordable year-round supply of lignocellulosic feedstocks is essential. Feedstock blending and/or densification offers one promising solution to overcome current challenges on biomass supply, i.e., low energy and bulk densities and significant compositional variations. Therefore, it is imperative to develop conversion technologies that can process mixed pelleted biomass feedstocks with minimal negative impact in terms of overall performance of the relevant biorefinery unit operations: pretreatment, fermentable sugar production, and fuel titers. We processed the mixture of four feedstocks—corn stover, switchgrass, lodgepole pine, and eucalyptus (1:1:1:1 on dry weight basis)—in flour and pellet form using ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate, dilute sulfuric acid (DA), and soaking in aqueous ammonia (SAA) pretreatments. Commercial enzyme mixtures, including cellulases and hemicellulases, were then applied to these pretreated feedstocks at low to moderate enzyme loadings to determine hydrolysis efficiency. Results show significant variations on the chemical composition, crystallinity, and enzymatic digestibility of the pretreated feedstocks across the different pretreatment technologies studied. The advanced biofuel isopentenol was produced during simultaneous saccharification and fermentation (SSF) of pretreated feedstocks using an engineered Escherichia coli strain. Results show that IL pretreatment liberates the most sugar during enzymatic saccharification, and in turn led to the highest isopentenol titer as compared to DA and SAA pretreatments. This study provides insights on developing biorefinery technologies that produce advanced biofuels based on mixed feedstock streams.

Antioxidative Peptides Derived from Enzyme Hydrolysis of Bone Collagen after Microwave Assisted Acid Pre-Treatment and Nitrogen Protection

Directory of Open Access Journals (Sweden)

Jin Sun

2010-11-01

Full Text Available This study focused on the preparation method of antioxidant peptides by enzymatic hydrolysis of bone collagen after microwave assisted acid pre-treatment and nitrogen protection. Phosphoric acid showed the highest ability of hydrolysis among the four other acids tested (hydrochloric acid, sulfuric acid and/or citric acid. The highest degree of hydrolysis (DH was 9.5% using 4 mol/L phosphoric acid with a ratio of 1:6 under a microwave intensity of 510 W for 240 s. Neutral proteinase gave higher DH among the four protease tested (Acid protease, neutral protease, Alcalase and papain, with an optimum condition of: (1 ratio of enzyme and substrate, 4760 U/g; (2 concentration of substrate, 4%; (3 reaction temperature, 55 °C and (4 pH 7.0. At 4 h, DH increased significantly (P < 0.01 under nitrogen protection compared with normal microwave assisted acid pre-treatment hydrolysis conditions. The antioxidant ability of the hydrolysate increased and reached its maximum value at 3 h; however DH decreased dramatically after 3 h. Microwave assisted acid pre-treatment and nitrogen protection could be a quick preparatory method for hydrolyzing bone collagen.

Compositional variability of nutrients and phytochemicals in corn after processing.

Science.gov (United States)

Prasanthi, P S; Naveena, N; Vishnuvardhana Rao, M; Bhaskarachary, K

2017-04-01

The result of various process strategies on the nutrient and phytochemical composition of corn samples were studied. Fresh and cooked baby corn, sweet corn, dent corn and industrially processed and cooked popcorn, corn grits, corn flour and corn flakes were analysed for the determination of proximate, minerals, xanthophylls and phenolic acids content. This study revealed that the proximate composition of popcorn is high compared to the other corn products analyzed while the mineral composition of these maize products showed higher concentration of magnesium, phosphorus, potassium and low concentration of calcium, manganese, zinc, iron, copper, and sodium. Popcorn was high in iron, zinc, copper, manganese, sodium, magnesium and phosphorus. The xanthophylls lutein and zeaxanthin were predominant in the dent corn and the total polyphenolic content was highest in dent corn while the phenolic acids distribution was variable in different corn products. This study showed preparation and processing brought significant reduction of xanthophylls and polyphenols.

Lignin Sulfonation and SO2 Addition Enhance the Hydrolyzability of Deacetylated and Then Steam-Pretreated Poplar with Reduced Inhibitor Formation.

Science.gov (United States)

Tang, Yong; Dou, Xiaoli; Hu, Jinguang; Jiang, Jianxin; Saddler, Jack N

2018-01-01

The merit of deacetylation of corn stover prior to pretreatment is decreasing the formation of inhibitors and improving enzyme hydrolysis, proved in dilute acid pretreatment. However, few studies are done on how deacetylation would affect bioconversion process containing steam explosion. In this study, the effect of deacetylation on steam explosion was conducted using poplar as substrate. About 57 to 90% of acetyl group in poplar, depending on alkaline types and concentration, was removed by dilute alkaline deacetylation in 6 h. Deacetylation eliminated over 85% of inhibitor formation during downstream steam explosion. However, deacetylation prior to steam explosion decreased the dissolution of hemicellulose, thus reducing the cellulose accessibility of pretreated poplar, finally resulting in 5-20% decrease in glucose yield and 20-35% decrease in xylose yield. The addition of 5% SO 2 during steam explosion significantly improved the hydrolysis of deacetylated and pretreated poplar without significantly increasing the concentration of inhibitors. Incorporating 45 mmol/kg sulfoacid group in lignin fraction of deacetylated and then pretreated poplar dramatically improved the xylose yield to about 100% and increased the glucose yield by 30%.

Hydrogenation impairs the hypolipidemic effect of corn oil in humans. Hydrogenation, trans fatty acids, and plasma lipids.

Science.gov (United States)

Lichtenstein, A H; Ausman, L M; Carrasco, W; Jenner, J L; Ordovas, J M; Schaefer, E J

1993-02-01

The effects of plasma lipoproteins and apolipoproteins of replacing corn oil with corn-oil margarine in stick form as two thirds of the fat in the National Cholesterol Education Program (NCEP) Step 2 diet were assessed in 14 middle-aged and elderly women and men (age range, 44-78 years) with moderate hypercholesterolemia (low density lipoprotein cholesterol [LDL-C] range, 133-219 mg/dl [3.45-5.67 mmol/l] at screening). During each 32-day study phase, subjects received all their food and drink from a metabolic kitchen. Subjects were first studied while being fed a diet approximating the composition of the current US diet (baseline), which contained 35% of calories as fat (13% saturated fatty acids [SFAs], 12% monounsaturated fatty acids [MUFAs; 0.8% 18:1n-9 trans], and 8% polyunsaturated fatty acids [PUFAs]) and 128 mg cholesterol/1,000 kcal. This baseline phase was followed by a corn oil-enriched diet containing 30% fat (6% SFA, 11% MUFA [0.4% 18:1n-9 trans], and 10% PUFA) and 83 mg cholesterol/1,000 kcal, and then a corn-oil margarine-enriched diet containing 30% fat (8% SFA, 12% MUFA [4.2% 18:1n-9 trans], and 8% PUFA) and 77 mg cholesterol/1,000 kcal. All diets were isocaloric. Mean fasting LDL-C and apolipoprotein (apo) B levels were 153 mg/dl (3.96 mmol/l) and 101 mg/dl on the baseline diet, 17% and 20% lower (both p oil-enriched diet, and 10% and 10% lower (both p < 0.01) on the margarine-enriched diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Adsorptive detoxification of fermentation inhibitors in acid pretreated liquor using functionalized polymer designed by molecular simulation.

Science.gov (United States)

Devendra, Leena P; Pandey, Ashok

2017-11-01

Acid pretreatment is the most common method employed in the lignocellulosic biorefinery leading to the separation of pentose and hexose sugar. The liquor obtained after pretreatment (acid pretreatment liquor or APL) needs to be detoxified prior to fermentation. The aim of this study was to design functional groups on a polymer matrix which are selective in their interaction to inhibitors with little or no specificity to sugars. Molecular modeling was used as a tool to design a suitable adsorbent for selective adsorption of inhibitors from a complex mixture of APL. Phenyl glycine-p-sulfonic acid loaded on chloromethylated polystyrene polymer was designed as an adsorbent for selective interaction with inhibitors. Experimental verification of the selectivity was successfully achieved. The current study provides insights on the adsorptive separation processes at the molecular level by design of specific adsorbent which can be tailor made for the better selectivity of the desired component.

Pretreatment and fermentation strategies to overcome the toxicity of acetic acid in hemicellulosic hydrolysates

DEFF Research Database (Denmark)

Mussatto, Solange I.

Acetic acid is one of the most important toxic compounds present in hemicellulosic hydrolysates. In order to overcome this problem, several strategies were studied for both biomass pretreatment and fermentation steps. Biomass deacetylation by mild alkaline pretreatment or using high pressure CO2...... where acetic acid can also be integrated as a valuable final product. For the fermentation step, it is well known that hemicellulosic hydrolysates usually need to be detoxified prior use as fermentation medium in order to improve the performance of the microorganism to convert sugars in the product...... of interest. Although detoxification improves the fermentability of hydrolysates, this additional step adds cost and complexity to the process and generates extra waste products. In this sense, the adaptation of the fermenting microorganism to increased concentrations of acetic acid can be considered...

Effect of γ-rays irradiation and alkali solution pretreatment on hydrolyzing enzyme and microcosmic structure of core straw

International Nuclear Information System (INIS)

Tang Hongtao; Wang Feng; Li Weiming; Li An; Ha Yiming; Li Yanjie

2012-01-01

To increase yield of reducing sugar enzymatic hydrolyzed from corn straw yield of corn stalk on Enzymatic hydrolysis, γ-rays radiation and NaOH solution pretreatment were used. The changes of microstructure of the corn straw before and after pretreatments were characterized by IR, X-rays diffraction and SEM. The results shows that the γ-rays radiation can significantly decrease the essential concentration of NaOH solution and shorten the immersion time, but it could not affected the yield of reducing sugar remarkably. The scanning electron microscopy (SEM) results show that the sample which was treated at the 200 kGy irradiation dose and NaOH solution circumstance has the biggest surface area increase. The reducing sugar content of enzyme hydrolyzed corn straw treated at 200 kGy irradiation dose and 2% NaOH solution was achieved 48.34%, which provides the theoretical basis for industry ethanol production using enzyme hydrolyzed corn straw. (authors)

Phenolic Acid Content and Antioxidant Properties of Extruded Corn Snacks Enriched with Kale

Science.gov (United States)

Kasprzak, Kamila; Oniszczuk, Tomasz; Waksmundzka-Hajnos, Monika; Nowak, Renata; Polak, Renata

2018-01-01

Prohealth food contains specific components which have positive influence on the health and well-being of the consumer. An important position among bioactive compounds occurs for polyphenols. Many results have indicated that an increased intake of phenolic compounds may reduce the risk of cardiovascular diseases and type 2 diabetes. The objective of the study was production of extruded corn snacks with addition (0, 2, 4, 6, and 8%) of kale (Brassica oleracea L. var. sabellica)—a polyphenol-rich plant. Afterwards, high-performance liquid chromatography-mass spectrometry (LC-ESI-MS/MS) and antioxidant activity analyses of snack extracts were performed. In the corn snacks enriched with kale, fifteen phenolic acids were indicated. These were protocatechuic, 4-OH-benzoic, vanillic, trans-caffeic, cis-caffeic, trans-p-coumaric, cis-p-coumaric, trans-ferulic, cis-ferulic, salicylic, gentisic, syringic, 3-OH-cinnamic, trans-sinapic, and cis-sinapic acids. Both the qualitative and quantitative content of polyphenols increased with the addition of B. oleracea. Data from spectrophotometric analyses of the samples showed high DPPH radical scavenging potential of snacks enriched with 4, 6, and 8% of kale. Snacks enriched with kale contain high level of phenolic acids and, therefore, have great potential to make a valuable source of natural antioxidants. High-temperature short-time extrusion-cooking process had no negative impact on polyphenol's activity. PMID:29507816

Phenolic Acid Content and Antioxidant Properties of Extruded Corn Snacks Enriched with Kale

Directory of Open Access Journals (Sweden)

Kamila Kasprzak

2018-01-01

Full Text Available Prohealth food contains specific components which have positive influence on the health and well-being of the consumer. An important position among bioactive compounds occurs for polyphenols. Many results have indicated that an increased intake of phenolic compounds may reduce the risk of cardiovascular diseases and type 2 diabetes. The objective of the study was production of extruded corn snacks with addition (0, 2, 4, 6, and 8% of kale (Brassica oleracea L. var. sabellica—a polyphenol-rich plant. Afterwards, high-performance liquid chromatography-mass spectrometry (LC-ESI-MS/MS and antioxidant activity analyses of snack extracts were performed. In the corn snacks enriched with kale, fifteen phenolic acids were indicated. These were protocatechuic, 4-OH-benzoic, vanillic, trans-caffeic, cis-caffeic, trans-p-coumaric, cis-p-coumaric, trans-ferulic, cis-ferulic, salicylic, gentisic, syringic, 3-OH-cinnamic, trans-sinapic, and cis-sinapic acids. Both the qualitative and quantitative content of polyphenols increased with the addition of B. oleracea. Data from spectrophotometric analyses of the samples showed high DPPH radical scavenging potential of snacks enriched with 4, 6, and 8% of kale. Snacks enriched with kale contain high level of phenolic acids and, therefore, have great potential to make a valuable source of natural antioxidants. High-temperature short-time extrusion-cooking process had no negative impact on polyphenol’s activity.

Phenolic Acid Content and Antioxidant Properties of Extruded Corn Snacks Enriched with Kale.

Science.gov (United States)

Kasprzak, Kamila; Oniszczuk, Tomasz; Wójtowicz, Agnieszka; Waksmundzka-Hajnos, Monika; Olech, Marta; Nowak, Renata; Polak, Renata; Oniszczuk, Anna

2018-01-01

Prohealth food contains specific components which have positive influence on the health and well-being of the consumer. An important position among bioactive compounds occurs for polyphenols. Many results have indicated that an increased intake of phenolic compounds may reduce the risk of cardiovascular diseases and type 2 diabetes. The objective of the study was production of extruded corn snacks with addition (0, 2, 4, 6, and 8%) of kale ( Brassica oleracea L. var. sabellica )-a polyphenol-rich plant. Afterwards, high-performance liquid chromatography-mass spectrometry (LC-ESI-MS/MS) and antioxidant activity analyses of snack extracts were performed. In the corn snacks enriched with kale, fifteen phenolic acids were indicated. These were protocatechuic, 4-OH-benzoic, vanillic, trans -caffeic, cis -caffeic, trans -p-coumaric, cis -p-coumaric, trans -ferulic, cis -ferulic, salicylic, gentisic, syringic, 3-OH-cinnamic, trans -sinapic, and cis -sinapic acids. Both the qualitative and quantitative content of polyphenols increased with the addition of B. oleracea . Data from spectrophotometric analyses of the samples showed high DPPH radical scavenging potential of snacks enriched with 4, 6, and 8% of kale. Snacks enriched with kale contain high level of phenolic acids and, therefore, have great potential to make a valuable source of natural antioxidants. High-temperature short-time extrusion-cooking process had no negative impact on polyphenol's activity.

Engineering and two-stage evolution of a lignocellulosic hydrolysate-tolerant Saccharomyces cerevisiae strain for anaerobic fermentation of xylose from AFEX pretreated corn stover.

Directory of Open Access Journals (Sweden)

Lucas S Parreiras

Full Text Available The inability of the yeast Saccharomyces cerevisiae to ferment xylose effectively under anaerobic conditions is a major barrier to economical production of lignocellulosic biofuels. Although genetic approaches have enabled engineering of S. cerevisiae to convert xylose efficiently into ethanol in defined lab medium, few strains are able to ferment xylose from lignocellulosic hydrolysates in the absence of oxygen. This limited xylose conversion is believed to result from small molecules generated during biomass pretreatment and hydrolysis, which induce cellular stress and impair metabolism. Here, we describe the development of a xylose-fermenting S. cerevisiae strain with tolerance to a range of pretreated and hydrolyzed lignocellulose, including Ammonia Fiber Expansion (AFEX-pretreated corn stover hydrolysate (ACSH. We genetically engineered a hydrolysate-resistant yeast strain with bacterial xylose isomerase and then applied two separate stages of aerobic and anaerobic directed evolution. The emergent S. cerevisiae strain rapidly converted xylose from lab medium and ACSH to ethanol under strict anaerobic conditions. Metabolomic, genetic and biochemical analyses suggested that a missense mutation in GRE3, which was acquired during the anaerobic evolution, contributed toward improved xylose conversion by reducing intracellular production of xylitol, an inhibitor of xylose isomerase. These results validate our combinatorial approach, which utilized phenotypic strain selection, rational engineering and directed evolution for the generation of a robust S. cerevisiae strain with the ability to ferment xylose anaerobically from ACSH.

Oxalic acid pretreatment of rice straw particles and loblolly pine chips : release of hemicellulosic carbohydrates

Science.gov (United States)

Xianjun Li; Zhiyong Cai; Eric Horn; Jerrold E. Winandy

2011-01-01

This study was conducted to evaluate the effect of oxalic acid (OA) pretreatment on carbohydrates released from rice straw particles and wood chips. The results showed that OA treatment accelerated carbohydrates extraction from rice straw particles and wood chips. OA pretreatment dramatically increased the amount of carbohydrates extracted, up to 24 times for wood...

Nephroprotective effect of Corn Silk extract on oxalic acid-induced nephrocalcinosis in rabbit model

Directory of Open Access Journals (Sweden)

Faruk Hassan Al-Jawad

2012-04-01

Full Text Available ABSTRACT Background : Nephrocalcinosis is a state of deposition of calcium phosphate or oxalate in the renal parenchyma. It may occur in patients with renal tubular acidosis, vitamin D intoxication, and hyperparathyroidism. Corn silk was used in traditional Chinese medicine to relieve renal pains. Aim: To evaluate the effect of Corn silk aqueous extract in reducing calcium deposits from renal parenchyma in oxalic acid-induced nephrocalcinosis model. Materials and methods: Fourteen healthy rabbits were allocated to two groups. Two hours before induction of nephrocalcinosis, one group received water and the other received aqueous extract of corn silk and continued feeding for ten days. Blood samples were collected for biochemical analysis before induction and in the fifth and tenth post-induction day. Urine samples were taken to estimate urinary ca+2 levels and crystals. The histopathological examination was carried to check for crystal deposits in renal tissues. Results: Corn silk aqueous extract produced a significant reduction of blood urea nitrogen(5.2+/-0.08 vs 7.3+/-0.2 mmol/l, serum creatinine (85.9+/-0.2 vs 97.3+/-0.5 mmol/l and serum Na+ levels (137+/-0.2 vs 142.16+/-0.7 mmol/l with non-significant reduction in serum K+ (4.0+/-0.02 vs 4.2+/-0.05. There is a significant reduction in calcium deposition in renal parenchyma in comparison to the control group after ten days of treatment. Conclusion: Corn silk had a significant diuretic effect that accelerates the excretion of urinary calcium. [J Intercult Ethnopharmacol 2012; 1(2.000: 75-78

Composition of forage and grain from second-generation insect-protected corn MON 89034 is equivalent to that of conventional corn (Zea mays L.).

Science.gov (United States)

Drury, Suzanne M; Reynolds, Tracey L; Ridley, William P; Bogdanova, Natalia; Riordan, Susan; Nemeth, Margaret A; Sorbet, Roy; Trujillo, William A; Breeze, Matthew L

2008-06-25

Insect-protected corn hybrids containing Cry insecticidal proteins derived from Bacillus thuringiensis have protection from target pests and provide effective management of insect resistance. MON 89034 hybrids have been developed that produce both the Cry1A.105 and Cry2Ab2 proteins, which provide two independent modes of insecticidal action against the European corn borer ( Ostrinia nubilalis ) and other lepidopteran insect pests of corn. The composition of MON 89034 corn was compared to conventional corn by measuring proximates, fiber, and minerals in forage and by measuring proximates, fiber, amino acids, fatty acids, vitamins, minerals, antinutrients, and secondary metabolites in grain collected from 10 replicated field sites across the United States and Argentina during the 2004-2005 growing seasons. Analyses established that the forage and grain from MON 89034 are compositionally comparable to the control corn hybrid and conventional corn reference hybrids. These findings support the conclusion that MON 89034 is compositionally equivalent to conventional corn hybrids.

Variability in amino acid digestibility and metabolizable energy of corn studied in cecectomized laying hens1.

Science.gov (United States)

Zuber, T; Rodehutscord, M

2017-06-01

To optimize the use of corn grain in diets for laying hens, differences in amino acid (AA) digestibility and metabolizable energy among different corn samples should be considered in feed formulation. The present study investigated the variability of AA digestibility and AMEn concentration of 20 corn samples in cecectomized laying hens. Corn grains were characterized based on their physical properties (thousand seed weight, test weight, grain density, and extract viscoelasticity), chemical composition (proximate nutrients, AA, minerals, and inositol phosphates), gross energy concentration, and in vitro solubility of nitrogen to study any relationship with AA digestibility or AMEn. The animal study comprised 4 Latin squares (6 × 6) distributed between 2 subsequent runs. Cecectomized LSL-Classic hens were individually housed in metabolism cages and fed either a basal diet containing 500 g/kg cornstarch or one of 20 corn diets, each replacing the cornstarch with one corn batch, for 8 days. During the last 4 d, feed intake was recorded and excreta were collected quantitatively. A linear regression approach was used to calculate AA digestibility of the corn. The digestibility of all AA differed significantly between the 20 corn batches, including Lys (digestibility range 64 to 85%), Met (86 to 94%), Thr (72 to 89%), and Trp (21 to 88%). The AMEn of the corn batches ranged between 15.7 and 17.1 MJ/kg DM. However, consistent correlations between AA digestibility or AMEn and the physical and chemical characteristics of the grains were not detected. Equations to predict AA digestibility or AMEn based on the grain's physical and chemical characteristics were calculated by multiple linear regressions. The explanatory power (adjusted R2;) of prediction equations was below 0.6 for the majority of AA and AMEn, and, thus, was not sufficiently precise for practical use. Possible explanations for the variation in AA digestibility and AMEn beyond the determined characteristics

Comparison of microwave and conduction-convection heating autohydrolysis pretreatment for bioethanol production.

Science.gov (United States)

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

2017-11-01

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.

CADMIUM AND LEAD STATUS IN CORN HYBRIDS GROWN ON ACID SOIL OF EASTERN CROATIA

Directory of Open Access Journals (Sweden)

V. Kovačević

2002-06-01

Full Text Available Twenty corn (Zea mays L. hybrids were grown under field conditions in the west part of Brodsko-posavska county in Eastern Croatia during 2000 and 2001 growing seasons. The field trial was conducted in four replicates. The ear-leaf at beginning of silking stage (the second decade of July was taken for chemical analysis from each plot. Mean soil sample was taken by auger to 30 cm of depth. The total amounts of Cd and Pb in corn leaves were measured by ICP-AES technique after their microwave digestion using concentrated HNO3+H2O2. Mobile fraction of these elements in soil was extracted by ammonium acetate-EDTA solution. The experimental field is acid hydromorphic soil (locality Malino with moderate levels of mobile fractions of calcium, magnesium and aluminum. Also, mobile fraction of cadmium and lead are tolerable for growing of health food. Weather conditions during the study differed from the long-term mean. Low rainfall quantities during 5-months period and the higher air-temperatures characterized the 2000 growing season. Excess of rainfall in June and September, their shortage in July and August, as well as high temperatures in August, are main characteristics of weather during the corn growing seasons in 2001. Mean concentrations of cadmium and lead in corn leaves in our investigations were 0.14 ppm Cd and 0.420 ppm Pb. These amounts are low and not dangerous for plants, because critical concentrations of Cd and Pb in plants ranged from 5 to 10 ppm Cd and 10-20 ppm Pb. Considerable differences of cadmium and lead status in the ear-leaf were found among tested corn hybrids. For example, genetically induced differences from 0.07 to 0.21 ppm Cd were found, while these values for Pb were from 0.241 to 0.569 ppm Pb. Especially low Cd concentrations were found in six corn hybrids (OsSK373, E9917/99, Bc278, OsSK2-191, OsSK382 and Clarica: mean 0.092 ppm Cd, while in three hybrids it was considerably higher, but acceptable from the aspect of plant

Reductive Catalytic Fractionation of Corn Stover Lignin

Energy Technology Data Exchange (ETDEWEB)

Anderson, Eric M.; Katahira, Rui; Reed, Michelle; Resch, Michael G.; Karp, Eric M.; Beckham, Gregg T.; Román-Leshkov, Yuriy

2016-12-05

Reductive catalytic fractionation (RCF) has emerged as an effective biomass pretreatment strategy to depolymerize lignin into tractable fragments in high yields. We investigate the RCF of corn stover, a highly abundant herbaceous feedstock, using carbon-supported Ru and Ni catalysts at 200 and 250 degrees C in methanol and, in the presence or absence of an acid cocatalyst (H3PO4 or an acidified carbon support). Three key performance variables were studied: (1) the effectiveness of lignin extraction as measured by the yield of lignin oil, (2) the yield of monomers in the lignin oil, and (3) the carbohydrate retention in the residual solids after RCF. The monomers included methyl coumarate/ferulate, propyl guaiacol/syringol, and ethyl guaiacol/syringol. The Ru and Ni catalysts performed similarly in terms of product distribution and monomer yields. The monomer yields increased monotonically as a function of time for both temperatures. At 6 h, monomer yields of 27.2 and 28.3% were obtained at 250 and 200 degrees C, respectively, with Ni/C. The addition of an acid cocatalysts to the Ni/C system increased monomer yields to 32% for acidified carbon and 38% for phosphoric acid at 200 degrees C. The monomer product distribution was dominated by methyl coumarate regardless of the use of the acid cocatalysts. The use of phosphoric acid at 200 degrees C or the high temperature condition without acid resulted in complete lignin extraction and partial sugar solubilization (up to 50%) thereby generating lignin oil yields that exceeded the theoretical limit. In contrast, using either Ni/C or Ni on acidified carbon at 200 degrees C resulted in moderate lignin oil yields of ca. 55%, with sugar retention values >90%. Notably, these sugars were amenable to enzymatic digestion, reaching conversions >90% at 96 h. Characterization studies on the lignin oils using two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance and gel permeation chromatrography revealed

21 CFR 73.315 - Corn endosperm oil.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 1 2010-04-01 2010-04-01 false Corn endosperm oil. 73.315 Section 73.315 Food and... ADDITIVES EXEMPT FROM CERTIFICATION Foods § 73.315 Corn endosperm oil. (a) Identity. (1) The color additive corn endosperm oil is a reddish-brown liquid composed chiefly of glycerides, fatty acids, sitosterols...

Lignite pre-treatment and its effect on bio-stimulative properties of respective lignite humic acids

Energy Technology Data Exchange (ETDEWEB)

Vlckova, Z.; Grasset, L.; Antosova, B.; Pekar, M.; Kucerik, J. [Brno University of Technology, Brno (Czech Republic). Faculty of Chemistry

2009-09-15

Humic acids originating from South-Moravian lignite were subjected to a comparative study with the aim to assess the alteration of their physico-chemical properties after various lignite pre-treatments. Physical modification was achieved with two organic acids, such as acetic acid and citric acid and chemical modification by nitric acid and hydrogene peroxide in various concentrations. Elemental analysis, solid-state NMR, GC-MS analysis of polyols and size exclusion chromatography were carried out for chemical-physical characterization of obtained humic acids. Their biological effect, in form of potassium and ammonium humates, was tested on maize (Zea mays) seedlings. In these tests, potassium humates achieved far better overall results than ammonium humates. Results were inter-correlated in order to appraise the influence of humic acids physical and chemical properties on biological activity. Surprisingly, fractions with the lowest molecular size (0-35 kDa) showed no correlation with bioactivity results (Pearson coefficient from 0.05 to -0.4). On the contrary, middle-sized fractions (35-175 kDa) showed highly significant positive correlation (Pearson coefficient up to 0.92) and the highest molecular-size-fractions (275-350 kDa) showed negative correlation (Pearson coefficient up to -0.75). These findings were identical for both potassium and ammonium humates. No connection was found between bioactivity of humates and polyols content which was remarkably high; it reached 150 mg per g of humic acids in the most extreme case of 5% hydrogene peroxide pre-treatment. In the final analysis, the preparation mode bore pivotal responsibility for the control of humic acids biological effect and showed the best results for potassium humates obtained from lignite pre-treated by acetic acid and by 2% hydrogen peroxide.

Kernel compositions of glyphosate-tolerant and corn rootworm-protected MON 88017 sweet corn and insect-protected MON 89034 sweet corn are equivalent to that of conventional sweet corn (Zea mays).

Science.gov (United States)

Curran, Kassie L; Festa, Adam R; Goddard, Scott D; Harrigan, George G; Taylor, Mary L

2015-03-25

Monsanto Co. has developed two sweet corn hybrids, MON 88017 and MON 89034, that contain biotechnology-derived (biotech) traits designed to enhance sustainability and improve agronomic practices. MON 88017 confers benefits of glyphosate tolerance and protection against corn rootworm. MON 89034 provides protection against European corn borer and other lepidopteran insect pests. The purpose of this assessment was to compare the kernel compositions of MON 88017 and MON 89034 sweet corn with that of a conventional control that has a genetic background similar to the biotech sweet corn but does not express the biotechnology-derived traits. The sweet corn samples were grown at five replicated sites in the United States during the 2010 growing season and the conventional hybrid and 17 reference hybrids were grown concurrently to provide an estimate of natural variability for all assessed components. The compositional analysis included proximates, fibers, amino acids, sugars, vitamins, minerals, and selected metabolites. Results highlighted that MON 88017 and MON 89034 sweet corns were compositionally equivalent to the conventional control and that levels of the components essential to the desired properties of sweet corn, such as sugars and vitamins, were more affected by growing environment than the biotech traits. In summary, the benefits of biotech traits can be incorporated into sweet corn with no adverse effects on nutritional quality.

Biohydrogen Production from Pineapple Waste: Effect of Substrate Concentration and Acid Pretreatment

Science.gov (United States)

Cahyari, K.; Putri, A. M.; Oktaviani, E. D.; Hidayat, M. A.; Norajsha, J. D.

2018-05-01

Biohydrogen is the ultimate choice of energy carrier in future due to its superior qualities such as fewer greenhouse gases emission, high energy density (142 kJ/gram), and high energy conversion using a fuel cell. Production of biohydrogen from organic waste e.g. pineapple waste offers a simultaneous solution for renewable energy production and waste management. It is estimated that pineapple cultivation in Indonesia generated more than 1 million ton/year comprising of rotten pineapple fruit, leaves, and stems. Majority of this waste is dumped into landfill area without any treatments which lead to many environmental problems. This research was meant to investigate the utilization of pineapple waste i.e. peel and the core of pineapple fruit and leaves to produce biohydrogen through mesophilic dark fermentation (30°C, 1 atm, pH 5.0). Effect of dilute acid treatment and substrate concentration was particularly investigated in these experiments. Peel and core of pineapple waste were subjected to fermentation at 3 various substrate concentration i.e. 8.8, 17.6 and 26.4-gram VS/liter. Meanwhile, pineapple leaves were pretreated using dilute acid (H2SO4) at 0.2, 0.3 and 0.4 N and followed by dark fermentation. Results show that the highest yield of biohydrogen was obtained at a substrate concentration of 26.4-gram VS/liter both for peel and core of the waste. Pretreatment using dilute acid (H2SO4) 0.3 N might improve fermentation process with a higher yield at 0.8 ml/gram VS. Hydrogen percentage in biogas produced during fermentation process was in the range between 5 – 32% of volume ratio. In summary, it is possible to utilize pineapple waste for production of biohydrogen at an optimum substrate concentration of 26.4-gram VS/liter and acid pretreatment (H2SO4) of 0.3 N.

Fractionation for further conversion: from raw corn stover to lactic acid

OpenAIRE

Ting He; Zhicheng Jiang; Ping Wu; Jian Yi; Jianmei Li; Changwei Hu

2016-01-01

Fractionation is considered to be one promising strategy to utilize raw biomass to its fullest and produce chemicals with high selectivity. Herein, ethanol/H2O (1/1, v/v) co-solvent with 0.050?M oxalic acid is used to simultaneously fractionate 88.0?wt% of hemicellulose and 89.2?wt% of lignin in corn stover, while cellulose is not obviously degraded. H2O dissolves hemicellulose, G unit and those with ?-O-4 linkage of lignin; whereas ethanol extracts G and S units as well as the skeleton with ...

40 CFR 406.14 - Pretreatment standards for existing sources.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 406.14 Section 406.14 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Wet Milling Subcategory § 406.14...

40 CFR 406.24 - Pretreatment standards for existing sources.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 28 2010-07-01 2010-07-01 true Pretreatment standards for existing sources. 406.24 Section 406.24 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) EFFLUENT GUIDELINES AND STANDARDS GRAIN MILLS POINT SOURCE CATEGORY Corn Dry Milling Subcategory § 406.24...

Structural features of dilute acid, steam exploded, and alkali pretreated mustard stalk and their impact on enzymatic hydrolysis.

Science.gov (United States)

Kapoor, Manali; Raj, Tirath; Vijayaraj, M; Chopra, Anju; Gupta, Ravi P; Tuli, Deepak K; Kumar, Ravindra

2015-06-25

To overcome the recalcitrant nature of biomass several pretreatment methodologies have been explored to make it amenable to enzymatic hydrolysis. These methodologies alter cell wall structure primarily by removing/altering hemicelluloses and lignin. In this work, alkali, dilute acid, steam explosion pretreatment are systematically studied for mustard stalk. To assess the structural variability after pretreatment, chemical analysis, surface area, crystallinity index, accessibility of cellulose, FT-IR and thermal analysis are conducted. Although the extent of enzymatic hydrolysis varies upon the methodologies used, nevertheless, cellulose conversion increases from adsorption capacity. However, no such relationship is observed for xylose yield. Mass balance of the process is also studied. Dilute acid pretreatment is the best methodology in terms of maximum sugar yield at lower enzyme loading. Copyright © 2015 Elsevier Ltd. All rights reserved.

A mutation of Aspergillus niger for hyper-production of citric acid from corn meal hydrolysate in a bioreactor*

Science.gov (United States)

Hu, Wei; Liu, Jing; Chen, Ji-hong; Wang, Shu-yang; Lu, Dong; Wu, Qing-hua; Li, Wen-jian

2014-01-01

The properties of the screened mutants for hyper-production of citric acid induced by carbon (12C6+) ion beams and X-ray irradiation were investigated in our current study. Among these mutants, mutant H4002 screened from 12C6+ ion irradiation had a higher yield of citric acid production than the parental strain in a 250-ml shaking flash. These expanded submerged experiments in a bioreactor were also carried out for mutant H4002. The results showed that (177.7–196.0) g/L citric acid was accumulated by H4002 through exploiting corn meal hydrolysate (containing initial 200.0–235.7 g/L sugar) with the productivity of (2.96–3.27) g/(L∙h). This was especially true when the initial sugar concentration was 210 g/L, and the best economical citric acid production reached (187.5±0.7) g/L with a productivity of 3.13 g/(L∙h). It was observed that mutant H4002 can utilize low-cost corn meal as a feedstock to efficiently produce citric acid. These results imply that the H4002 strain has the industrial production potentiality for citric acid and offers strong competition for the citric acid industry. PMID:25367793

A mutation of Aspergillus niger for hyper-production of citric acid from corn meal hydrolysate in a bioreactor.

Science.gov (United States)

Hu, Wei; Liu, Jing; Chen, Ji-hong; Wang, Shu-yang; Lu, Dong; Wu, Qing-hua; Li, Wen-jian

2014-11-01

The properties of the screened mutants for hyper-production of citric acid induced by carbon ((12)C(6+)) ion beams and X-ray irradiation were investigated in our current study. Among these mutants, mutant H4002 screened from (12)C(6+) ion irradiation had a higher yield of citric acid production than the parental strain in a 250-ml shaking flash. These expanded submerged experiments in a bioreactor were also carried out for mutant H4002. The results showed that (177.7-196.0) g/L citric acid was accumulated by H4002 through exploiting corn meal hydrolysate (containing initial 200.0-235.7 g/L sugar) with the productivity of (2.96-3.27) g/(L∙h). This was especially true when the initial sugar concentration was 210 g/L, and the best economical citric acid production reached (187.5±0.7) g/L with a productivity of 3.13 g/(L∙h). It was observed that mutant H4002 can utilize low-cost corn meal as a feedstock to efficiently produce citric acid. These results imply that the H4002 strain has the industrial production potentiality for citric acid and offers strong competition for the citric acid industry.

Induction of resistance of corn plants to Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) by application of silicon and gibberellic acid.

Science.gov (United States)

Alvarenga, R; Moraes, J C; Auad, A M; Coelho, M; Nascimento, A M

2017-08-01

The aim of this study was to evaluate the effects of silicon application and administration of the phytohormone gibberellic acid on resistance of the corn plants to the fall armyworm (FAW), Spodoptera frugiperda, and their vegetative characteristics. We evaluated larval and pupal duration, survival and biomass, and adult longevity, malformation and fecundity of S. frugiperda after feeding on plant matter treated with silicon and/or gibberellic acid. The feeding preference of FAW first-instar larvae, the total leaf area consumed by the insects, and the vegetative parameters of corn plants were also evaluated. No significant differences were observed in the measured parameters of larval and pupal stages of S. frugiperda in response to silicon or gibberellic acid. In adult stage insects, the number of eggs per female was significantly reduced in insects derived from larvae fed plants treated with silicon or gibberellic acid. In a non-preference test, 48 h after release, caterpillars preferred control untreated plants and consumed less matter from plants that had received hormonal treatment (gibberellic acid). Gibberellic acid also altered the vegetative characteristics of plants, by increasing their height, shoot fresh and dry mass, and silicon content. We conclude that gibberellic acid can alter the vegetative characteristics and silicon uptake of corn plants, leading to a reduction in their consumption by S. frugiperda larvae and a decrease in female insect oviposition.

Enzymatic hydrolsis of pretreated rice straw

Energy Technology Data Exchange (ETDEWEB)

Vlasenko, E.Y.; Shoemaker, S.P. [California Inst. of Food and Agricultural Research, Davis, CA (United States); Ding, H. [California Univ., Davis (Canada). Dept. of Food Science and Technology; Labavitch, J.M. [California Univ., Davis, CA (United States). Dept. of Pomology

1997-02-01

California rice straw is being evaluated as a feedstock for production of power and fuel. This paper examines the initial steps in the process: pretreatment of rice straw and enzymatic hydrolysis of the polysaccharides in the pretreated material to soluble sugars. Rice straw was subjected to three distinct pretreatment procedures: acid-catalyzed steam explosion (Swan Biomass Company), acid hydrolysis (U.S. DOE National Renewable Energy Laboratory), and ammonia fiber explosion or AFEX (Texas A and M University). Standard conditions for each pretreatment were used, but none was optimized for rice straw specifically. Six commercial cellulases, products of Genencor International (USA), Novo (Denmark), Iogen (Canada) and Fermtech (Russia) were used for hydrolysis. The Swan- and the acid-pretreatments effectively removed hemicellulose from rice straw, providing high yields of fermentable sugars. The AFEX-pretreatment was distinctly different from other pretreatments in that it did not significantly solubilize hemicellulose. All three pretreatment procedures substantially increased enzymatic digestibility of rice straw. Three commercial Trichoderma-reesei-derived enzyme preparations: Cellulase 100L (Iogen), Spezyme CP (Genencor), and Al (Fermtech), were more active on pretreated rice straw compared than others tested. Conditions for hydrolysis of rice straw using Cellulase 100L were evaluated. The supplementation of this enzyme preparation with cellobiase (Novozyme 188) significantly improved the parameters of hydrolysis for the Swan- and the acid-pretreated materials, but did not affect the hydrolysis of the AFEX-pretreated rice straw. (Author)

21 CFR 137.270 - Self-rising white corn meal.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Self-rising white corn meal. 137.270 Section 137... Cereal Flours and Related Products § 137.270 Self-rising white corn meal. (a) Self-rising white corn meal is an intimate mixture of white corn meal, sodium bicarbonate, and one or both of the acid-reacting...

Baby corn, green corn, and dry corn yield of corn cultivars

OpenAIRE

Castro,Renato S; Silva,Paulo Sérgio L; Cardoso,Milton J

2013-01-01

In corn, when the first female inflorescence is removed, the plant often produces new female inflorescences. This allows the first ear to be harvested as baby corn (BC) and the second as green corn (GC) or dry corn (DC), that is, mature corn. The flexibility provided by a variety of harvested products allows the grower to compete with better conditions in the markets. We evaluated BC, GC, and DC yields in corn cultivars AG 1051, AG 2060, and BRS 2020, after the first ear was harvested as BC. ...

In growing pigs, the true ileal and total tract digestibility of acid hydrolyzed ether extract in extracted corn oil is greater than in intact sources of corn oil or soybean oil.

Science.gov (United States)

Kim, B G; Kil, D Y; Stein, H H

2013-02-01

An experiment was conducted to determine the true ileal digestibility (TID) and the true total tract digestibility (TTTD) of acid-hydrolyzed ether extract (AEE) in extracted corn oil, high-oil corn, distillers dried grains with solubles (DDGS), corn germ, and high protein distillers dried grains (HP DDG) and to compare these values to the TID and TTTD of AEE in full-fat soybeans. Nineteen barrows with an initial BW of 52.2 kg (SD = 3.8) were fitted with a T-cannula in the distal ileum and allotted to a 19 × 11 Youden square design with 19 diets and 11 periods. A basal diet based on cornstarch, casein, sucrose, and corn bran was formulated. Eighteen additional diets were formulated by adding 3 levels of extracted corn oil, high-oil corn, DDGS, corn germ, HP DDG, or full-fat soybeans to the basal diet. The apparent ileal and the apparent total tract digestibility of AEE were calculated for each diet. The endogenous flow of AEE associated with each ingredient and values for TID and TTTD were calculated using the regression procedure. Results indicated that digested AEE in ileal digesta and feces linearly increased as AEE intake increased regardless of ingredient (P 0.77). However, the ileal and fecal endogenous losses of AEE were different (P oil, HP DDG, and full-fat soybeans. The TID of AEE was greater (P oil (95.4%) than for all other ingredients. The TID of AEE in HP DDG (76.5%) was not different from the TID of AEE in full-fat soybeans (85.2%) but greater (P oil corn, DDGS, and corn germ (53.0, 62.1, and 50.1%, respectively). The TTTD of AEE was greater (P oil (94.3%) than for all other ingredients, and the TTTD in full-fat soybeans (79.7%) was greater (P oil corn, DDGS, corn germ, and HP DDG (41.4, 51.9, 43.9, and 70.2%, respectively). The TTTD of AEE in HP DDG was also greater (P oil corn, DDGS, and corn germ. In conclusion, the intact sources of oil originating from high-oil corn, DDGS, corn germ, or HP DDG are much less digestible than extracted corn oil

Primary properties of MDF using thermomechanical pulp made from oxalic acid pretreated rice straw particles

Science.gov (United States)

Xianjun Li; Yiqiang Wu; Zhiyong Cai; Jerrold E. Winandy

2013-01-01

The main objective of this study is to evaluate the effect the oxalic acid (OA) and steam pretreatment on the primary properties of rice straw medium-density fiberboard (MDF). The results show the IB strength increased about 9.6% and 13.4% for steam-treated MDF (PC) and OA-treated MDF compared with raw control panels, while OA pretreatment has a slight negative effect...

Techno-economic comparison of centralized versus decentralized biorefineries for two alkaline pretreatment processes.

Science.gov (United States)

Stoklosa, Ryan J; Del Pilar Orjuela, Andrea; da Costa Sousa, Leonardo; Uppugundla, Nirmal; Williams, Daniel L; Dale, Bruce E; Hodge, David B; Balan, Venkatesh

2017-02-01

In this work, corn stover subjected to ammonia fiber expansion (AFEX™) 1 pretreatment or alkaline pre-extraction followed by hydrogen peroxide post-treatment (AHP pretreatment) were compared for their enzymatic hydrolysis yields over a range of solids loadings, enzymes loadings, and enzyme combinations. Process techno-economic models were compared for cellulosic ethanol production for a biorefinery that handles 2000tons per day of corn stover employing a centralized biorefinery approach with AHP or a de-centralized AFEX pretreatment followed by biomass densification feeding a centralized biorefinery. A techno-economic analysis (TEA) of these scenarios shows that the AFEX process resulted in the highest capital investment but also has the lowest minimum ethanol selling price (MESP) at $2.09/gal, primarily due to good energy integration and an efficient ammonia recovery system. The economics of AHP could be made more competitive if oxidant loadings were reduced and the alkali and sugar losses were also decreased. Copyright © 2016 Elsevier Ltd. All rights reserved.

Oxidative production of xylonic acid using xylose in distillation stillage of cellulosic ethanol fermentation broth by Gluconobacter oxydans.

Science.gov (United States)

Zhang, Hongsen; Han, Xushen; Wei, Chengxiang; Bao, Jie

2017-01-01

An oxidative production process of xylonic acid using xylose in distillation stillage of cellulosic ethanol fermentation broth was designed, experimentally investigated, and evaluated. Dry dilute acid pretreated and biodetoxified corn stover was simultaneously saccharified and fermented into 59.80g/L of ethanol (no xylose utilization). 65.39g/L of xylose was obtained in the distillation stillage without any concentrating step after ethanol was distillated. Then the xylose was completely converted into 66.42g/L of xylonic acid by Gluconobacter oxydans. The rigorous Aspen Plus modeling shows that the wastewater generation and energy consumption was significantly reduced comparing to the previous xylonic acid production process using xylose in pretreatment liquid. This study provided a practical process option for xylonic acid production from lignocellulose feedstock with significant reduction of wastewater and energy consumption. Copyright © 2016 Elsevier Ltd. All rights reserved.

Removal of fermentation inhibitors from alkaline peroxide pretreated and enzymatically hydrolyzed wheat straw: Production of butanol from hydrolysate using Clostridium beijerinckii in batch reactors

International Nuclear Information System (INIS)

Qureshi, Nasib; Saha, Badal C.; Hector, Ronald E.; Cotta, Michael A.

2008-01-01

In these studies, alkaline peroxide pretreatment of wheat straw was investigated. Pretreated wheat straw was hydrolyzed using cellulolytic and xylanolytic enzymes, and the hydrolysate was used to produce butanol using Clostridium beijerinckii P260. The culture produced less than 2.59 g L -1 acetone-butanol-ethanol (ABE) from alkaline peroxide wheat straw hydrolysate (APWSH) that had not been treated to reduce salt concentration (a neutralization product). However, fermentation was successful after inhibitors (salts) were removed from the hydrolysate by electrodialysis. A control glucose fermentation resulted in the production of 21.37 g L -1 ABE, while salt removed APWSH resulted in the production of 22.17 g L -1 ABE. In the two fermentations, reactor productivities were 0.30 and 0.55 g L -1 h -1 , respectively. A comparison of use of different substrates (corn fiber, wheat straw) and different pretreatment techniques (dilute sulfuric acid, alkaline peroxide) suggests that generation of inhibitors is substrate and pretreatment specific

Scale-up study of oxalic acid pretreatment of agricultural lignocellulosic biomass for the production of bioethanol

Science.gov (United States)

Jae-Won Lee; Carl J. Houtman; Hye-Yun Kim; In-Gyu Choi; Thomas W. Jeffries

2011-01-01

Building on our laboratory-scale optimization, oxalic acid was used to pretreat corncobs on the pilotscale. The hydrolysate obtained after washing the pretreated biomass contained 32.55 g/l of xylose, 2.74 g/l of glucose and low concentrations of inhibitors. Ethanol production, using Scheffersomyces stipitis, from this hydrolysate was 10.3 g/l, which approached the...

Nitrogen-corrected True Metabolizable Energy and Amino Acid Digestibility of Chinese Corn Distillers Dried Grains with Solubles in Adult Cecectomized Roosters

Directory of Open Access Journals (Sweden)

F. Li

2013-06-01

Full Text Available This study was conducted to evaluate chemical composition, nitrogen-corrected true metabolizable energy (TMEn and true amino acids digestibility of corn distillers dried grains with solubles (DDGS produced in China. Twenty five sources of corn DDGS was collected from 8 provinces of China. A precision-fed rooster assay was used to determine TMEn and amino acids digestibility with 35 adult cecectomized roosters, in which each DDGS sample was tube fed (30 g. The average content of ash, crude protein, total amino acid, ether extract, crude fiber and neutral detergent fiber were 4.81, 27.91, 22.51, 15.22, 6.35 and 37.58%, respectively. TMEn of DDGS ranged from 1,779 to 3,071 kcal/kg and averaged 2,517 kcal/kg. Coefficient of variation for non-amino acid crude protein, ether extract, crude fiber and TMEn were 55.0, 15.7, 15.9 and 17.1%, respectively. The average true amino acid digestibility was 77.32%. Stepwise regression analysis obtained the following equation: TMEn, kcal/kg = −2,995.6+0.88×gross energy+49.63×a* (BIC = 248.8; RMSE = 190.8; p0.05. These results suggest that corn DDGS produced in China has a large variation in chemical composition, and gross energy and a* value can be used to generate TMEn predict equation.

Phenolics and essential mineral profile of organic acid pretreated unripe banana flour.

Science.gov (United States)

Anyasi, Tonna A; Jideani, Afam I O; Mchau, Godwin R A

2018-02-01

Banana fruit (Musa spp) though rich in essential minerals, has also been implicated for the presence of phytochemicals which nonetheless beneficial, can also act as mineral inhibitors when in forms such as phenolic compounds, phytates and tannins. This study assayed the essential macro and trace minerals as well as phenolic compounds present in unripe banana flour (UBF) obtained from the pulp of four different cultivars. Unripe banana flour was processed by oven drying in a forced air oven dryer at 70°C upon pretreatment with ascorbic, citric and lactic acid. Organic acid pretreatment was done separately on each unripe banana cultivar at concentrations of 10, 15 and 20g/L. Phenolic compounds were profiled using liquid chromatography mass spectrometry electrospray ion (LC-MS-ESI) while essential minerals were determined using inductively coupled plasma atomic emission spectroscopy (ICP-AES) and mass spectroscopy (ICP-MS) respectively. Results of LC-MS-ESI assay of phenolics revealed the presence of flavonoids: epicatechin and myricetin 3-O-rhamnosyl-glucoside in varying concentrations in UBF. Essential mineral profile indicated that Zinc had the least occurrence of 3.55mg/kg (ppotassium was the most abundant mineral at 14746.73mg/kg in UBF of all four banana cultivars. Correlation between phenolic compounds and essential minerals using Pearson's Correlation Coefficient test revealed weak and inverse association between flavonoids and most macro and trace minerals present in UBF samples. Organic acid pretreatment thus exhibited little effect on phenolics and essential minerals of UBF samples, though, inhibitory influence of phenolic compounds was recorded on essential minerals. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Hydrolysis of corn oil using subcritical water

Directory of Open Access Journals (Sweden)

Pinto Jair Sebastião S.

2006-01-01

Full Text Available This work presents the results of a study on the use of subcritical water as both solvent and reactant for the hydrolysis of corn oil without the use of acids or alkalis at temperatures of 150-280 degreesC. Corn oil hydrolysis leads to the formation of its respective fatty acids with the same efficiency of conventional methods. Fatty acids form an important group of products, which are used in a range of applications. The confirmation and identification of the hydrolysis products was done by HT-HRGC-FID and HRGC/MS.

Lost P1 allele in sh2 sweet corn: quantitative effects of p1 and a1 genes on concentrations of maysin, apimaysin, methoxymaysin, and chlorogenic acid in maize silk.

Science.gov (United States)

Guo, B Z; Zhang, Z J; Butrón, A; Widstrom, N W; Snook, M E; Lynch, R E; Plaisted, D

2004-12-01

In the United States, insecticide is used extensively in the production of sweet corn due to consumer demand for zero damage to ears and to a sweet corn genetic base with little or no resistance to ear-feeding insects. Growers in the southern United States depend on scheduled pesticide applications to control ear-feeding insects. In a study of quantitative genetic control over silk maysin, AM-maysin (apimaysin and methoxymaysin), and chlorogenic acid contents in an F2 population derived from GE37 (dent corn, P1A1) and 565 (sh2 sweet corn, p1a1), we demonstrate that the P1 allele from field corn, which was selected against in the development of sweet corn, has a strong epistatic interaction with the a1 allele in sh2 sweet corn. We detected that the p1 gene has significant effects (P silk maysin concentrations but also on AM-maysin, and chlorogenic acid concentrations. The a1 gene also has significant (P silk antibiotic chemicals. Successful selection from the fourth and fifth selfed backcrosses for high-maysin individuals of sweet corn homozygous for the recessive a1 allele (tightly linked to sh2) and the dominant P1 allele has been demonstrated. These selected lines have much higher (2 to 3 times) concentrations of silk maysin and other chemicals (AM-maysin and chlorogenic acid) than the donor parent GE37 and could enhance sweet corn resistance to corn earworm and reduce the number of applications of insecticide required to produce sweet corn.

Alkaline Peroxide Delignification of Corn Stover

Energy Technology Data Exchange (ETDEWEB)

Mittal, Ashutosh [Biosciences; Katahira, Rui [National; Donohoe, Bryon S. [Biosciences; Black, Brenna A. [National; Pattathil, Sivakumar [Complex; Stringer, Jack M. [National; Beckham, Gregg T. [National

2017-05-30

Selective biomass fractionation into carbohydrates and lignin is a key challenge in the conversion of lignocellulosic biomass to fuels and chemicals. In the present study, alkaline hydrogen peroxide (AHP) pretreatment was investigated to fractionate lignin from polysaccharides in corn stover (CS), with a particular emphasis on the fate of the lignin for subsequent valorization. The influence of peroxide loading on delignification during AHP pretreatment was examined over the range of 30-500 mg H2O2/g dry CS at 50 degrees C for 3 h. Mass balances were conducted on the solid and liquid fractions generated after pretreatment for each of the three primary components, lignin, hemicellulose, and cellulose. AHP pretreatment at 250 mg H2O2/g dry CS resulted in the pretreated solids with more than 80% delignification consequently enriching the carbohydrate fraction to >90%. Two-dimensional nuclear magnetic resonance (2D-NMR) spectroscopy of the AHP pretreated residue shows that, under high peroxide loadings (>250 mg H2O2/g dry CS), most of the side chain structures were oxidized and the aryl-ether bonds in lignin were partially cleaved, resulting in significant delignification of the pretreated residues. Gel permeation chromatography (GPC) analysis shows that AHP pretreatment effectively depolymerizes CS lignin into low molecular weight (LMW) lignin fragments in the aqueous fraction. Imaging of AHP pretreated residues shows a more granular texture and a clear lamellar pattern in secondary walls, indicative of layers of varying lignin removal or relocalization. Enzymatic hydrolysis of this pretreated residue at 20 mg/g of glucan resulted in 90% and 80% yields of glucose and xylose, respectively, after 120 h. Overall, AHP pretreatment is able to selectively remove more than 80% of the lignin from biomass in a form that has potential for downstream valorization processes and enriches the solid pulp into a highly digestible material.

Production of bio-sugar and bioethanol from coffee residue (CR) by acid-chlorite pretreatment.

Science.gov (United States)

Kim, Ho Myeong; Choi, Yong-Soo; Lee, Dae-Seok; Kim, Yong-Hwan; Bae, Hyeun-Jong

2017-07-01

Nowadays, coffee residue (CR) after roasting is recognized as one of the most useful resources in the world for producing the biofuel and bio-materials. In this study, we evaluated the potential of bio-sugar and bioethanol production from acid-chlorite treated CR. Notably, CR treated three times with acid-chlorite after organic solvent extraction (OSE-3), showed the high monosaccharide content, and the efficient sugar conversion yield compared to the other pretreatment conditions. The OSE-3 (6% substrate loading, w/v) can produce bio-sugar (0.568g/g OSE-3). Also, simultaneous saccharification and fermentation (SSF) produced ethanol (0.266g/g OSE-3), and showed an ethanol conversion yield of 73.8% after a 72-h reaction period. These results suggest that acid-chlorite pretreatment can improve the bio-sugar and bioethanol production of CR by removing the phenolic and brown compounds. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phosphoric acid based pretreatment of switchgrass and fermentation of entire slurry to ethanol using a simplified process.

Science.gov (United States)

Wu, Wei; Rondon, Vanessa; Weeks, Kalvin; Pullammanappallil, Pratap; Ingram, Lonnie O; Shanmugam, K T

2018-03-01

Switchgrass (Alamo) was pretreated with phosphoric acid (0.75 and 1%, w/w) at three temperatures (160, 175 and 190 °C) and time (5, 7.5 and 10 min) using a steam gun. The slurry after pretreatment was liquefied by enzymes and the released sugars were fermented in a simultaneous saccharification and co-fermentation process to ethanol using ethanologenic Escherichia coli strain SL100. Among the three variables in pretreatment, temperature and time were critical in supporting ethanol titer and yield. Enzyme hydrolysis significantly increased the concentration of furans in slurries, apparently due to release of furans bound to the solids. The highest ethanol titer of 21.2 ± 0.3 g/L ethanol obtained at the pretreatment condition of 190-1-7.5 (temperature-acid concentration-time) and 10% solids loading accounted for 190 ± 2.9 g ethanol/kg of raw switch grass. This converts to 61.7 gallons of ethanol per ton of dry switchgrass, a value that is comparable to other published pretreatment conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Production of L(+)-lactic acid from acid pretreated sugarcane bagasse using Bacillus coagulans DSM2314 in a simultaneous saccharification and fermentation strategy

NARCIS (Netherlands)

Pol, van der Edwin C.; Eggink, Gerrit; Weusthuis, Ruud A.

2016-01-01

Background: Sugars derived from lignocellulose-rich sugarcane bagasse can be used as feedstock for production of L(+)-lactic acid, a precursor for renewable bioplastics. In our research, acid-pretreated bagasse was hydrolysed with the enzyme cocktail GC220 and fermented by the moderate

Application of a continuous twin screw-driven process for dilute acid pretreatment of rape straw.

Science.gov (United States)

Choi, Chang Ho; Oh, Kyeong Keun

2012-04-01

Rape straw, a processing residue generated from the bio-oil industry, was used as a model biomass for application of continuous twin screw-driven dilute acid pretreatment. The screw rotation speed and feeding rate were adjusted to 19.7rpm and 0.5g/min, respectively to maintain a residence time of 7.2min in the reaction zone, respectively. The sulfuric acid concentration was 3.5wt% and the reaction temperature was 165°C. The enzymatic digestibility of the glucan in the pretreated solids was 70.9%. The continuous process routinely gave around 28.8% higher yield for glucan digestibility than did the batch processing method. Copyright © 2012 Elsevier Ltd. All rights reserved.

Microbial Lipid Production from Enzymatic Hydrolysate of Pecan Nutshell Pretreated by Combined Pretreatment.

Science.gov (United States)

Qin, Lizhen; Qian, Hanyu; He, Yucai

2017-12-01

Biodiesel is a fuel composed of monoalkyl esters of long-chain fatty acids derived from renewable biomass sources. In this study, biomass waste pecan nutshell (PS) was attempted to be converted into microbial oil. For effective utilization of PS, sequential pretreatment with ethylene glycol-H 2 SO 4 -water (78:2:20, wt:wt:wt) at 130 °C for 30 min and aqueous ammonia (25 wt%) at 50 °C for 24 h was used to enhance its enzymatic saccharification. Significant linear correlation was obtained about delignification-saccharification (R 2  = 0.9507). SEM and FTIR results indicated that combination pretreatment could effectively remove lignin and xylan in PS for promoting its enzymatic saccharification. After 72 h, the reducing sugars from the hydrolysis of 50 g/L pretreated PS by combination pretreatment could be obtained at 73.6% yield. Using the recovered PS hydrolysates containing 20 g/L glucose as carbon source, microbial lipids produced from the PS hydrolysates by Rhodococcus opacus ACCC41043. Four fatty acids including palmitic acid (C16:0; 23.1%), palmitoleic acid (C16:1; 22.4%), stearic acid (C18:0; 15.3%), and oleic acid (C18:1; 23.9%) were distributed in total fatty acids. In conclusion, this strategy has potential application in the future.

Rheology of corn stover slurries during fermentation to ethanol

Science.gov (United States)

Ghosh, Sanchari; Epps, Brenden; Lynd, Lee

2017-11-01

In typical processes that convert cellulosic biomass into ethanol fuel, solubilization of the biomass is carried out by saccharolytic enzymes; however, these enzymes require an expensive pretreatment step to make the biomass accessible for solubilization (and subsequent fermentation). We have proposed a potentially-less-expensive approach using the bacterium Clostridium thermocellum, which can initiate fermentation without pretreatment. Moreover, we have proposed a ``cotreatment'' process, in which fermentation and mechanical milling occur alternately so as to achieve the highest ethanol yield for the least milling energy input. In order to inform the energetic requirements of cotreatment, we experimentally characterized the rheological properties of corn stover slurries at various stages of fermentation. Results show that a corn stover slurry is a yield stress fluid, with shear thinning behavior well described by a power law model. Viscosity decreases dramatically upon fermentation, controlling for variables such as solids concentration and particle size distribution. To the authors' knowledge, this is the first study to characterize the changes in the physical properties of biomass during fermentation by a thermophilic bacterium.

Ethanol production from corn cobs by co-culture of Saccharomyces ...

African Journals Online (AJOL)

Saccharomyces cerevisiae and Aspergillus niger were used in a co-culture for the simultaneous saccharification and fermentation (SSF) of 1% and 10% (w/v) dry pre-treated corn cobs to ethanol. Positive controls of glucose of same concentrations in a synthetic medium were also fermented. At 1% substrate concentration, ...

Fractionation for further conversion: from raw corn stover to lactic acid

Science.gov (United States)

He, Ting; Jiang, Zhicheng; Wu, Ping; Yi, Jian; Li, Jianmei; Hu, Changwei

2016-12-01

Fractionation is considered to be one promising strategy to utilize raw biomass to its fullest and produce chemicals with high selectivity. Herein, ethanol/H2O (1/1, v/v) co-solvent with 0.050 M oxalic acid is used to simultaneously fractionate 88.0 wt% of hemicellulose and 89.2 wt% of lignin in corn stover, while cellulose is not obviously degraded. H2O dissolves hemicellulose, G unit and those with β-O-4 linkage of lignin; whereas ethanol extracts G and S units as well as the skeleton with β-5 and β-β linkages of lignin. Oxalic acid effectively catalyzes the hydrolysis of hemicellulose and breaks the intermolecular linkages between hemicellulose and lignin, therefore further promotes the release of lignin. The dissolved hemicelluloses derivatives are reprocessed to produce lactic acid obtaining a high yield of 79.6 wt% with 90% selectivity by the catalysis of MgO. The remained cellulose and recovered lignin can be used further as feedstock to produce chemicals.

Fractionation for further conversion: from raw corn stover to lactic acid

Science.gov (United States)

He, Ting; Jiang, Zhicheng; Wu, Ping; Yi, Jian; Li, Jianmei; Hu, Changwei

2016-01-01

Fractionation is considered to be one promising strategy to utilize raw biomass to its fullest and produce chemicals with high selectivity. Herein, ethanol/H2O (1/1, v/v) co-solvent with 0.050 M oxalic acid is used to simultaneously fractionate 88.0 wt% of hemicellulose and 89.2 wt% of lignin in corn stover, while cellulose is not obviously degraded. H2O dissolves hemicellulose, G unit and those with β-O-4 linkage of lignin; whereas ethanol extracts G and S units as well as the skeleton with β-5 and β-β linkages of lignin. Oxalic acid effectively catalyzes the hydrolysis of hemicellulose and breaks the intermolecular linkages between hemicellulose and lignin, therefore further promotes the release of lignin. The dissolved hemicelluloses derivatives are reprocessed to produce lactic acid obtaining a high yield of 79.6 wt% with 90% selectivity by the catalysis of MgO. The remained cellulose and recovered lignin can be used further as feedstock to produce chemicals. PMID:27917955

Pretreatment of Biomass by Aqueous Ammonia for Bioethanol Production

Science.gov (United States)

Kim, Tae Hyun; Gupta, Rajesh; Lee, Y. Y.

The methods of pretreatment of lignocellulosic biomass using aqueous ammonia are described. The main effect of ammonia treatment of biomass is delignification without significantly affecting the carbohydrate contents. It is a very effective pretreatment method especially for substrates that have low lignin contents such as agricultural residues and herbaceous feedstock. The ammonia-based pretreatment is well suited for simultaneous saccharification and co-fermentation (SSCF) because the treated biomass retains cellulose as well as hemicellulose. It has been demonstrated that overall ethanol yield above 75% of the theoretical maximum on the basis of total carbohydrate is achievable from corn stover pretreated with aqueous ammonia by way of SSCF. There are two different types of pretreatment methods based on aqueous ammonia: (1) high severity, low contact time process (ammonia recycle percolation; ARP), (2) low severity, high treatment time process (soaking in aqueous ammonia; SAA). Both of these methods are described and discussed for their features and effectiveness.

Xylanase supplementation on enzymatic saccharification of dilute acid pretreated poplars at different severities

Science.gov (United States)

Chao Zhang; Xinshu Zhuang; Zhao Jiang Wang; Fred Matt; Franz St. John; J.Y. Zhu

2013-01-01

Three pairs of solid substrates from dilute acid pretreatment of two poplar wood samples were enzymatically hydrolyzed by cellulase preparations supplemented with xylanase. Supplementation of xylanase improved cellulose saccharification perhaps due to improved cellulose accessibility by xylan hydrolysis. Total xylan removal directly affected enzymatic cellulose...

Optimization of alkaline and dilute acid pretreatment of agave bagasse by response surface methodology

Directory of Open Access Journals (Sweden)

Abimael I. Ávila-Lara

2015-09-01

Full Text Available Utilization of lignocellulosic materials for the production of value-added chemicals or biofuels generally requires a pretreatment process to overcome the recalcitrance of the plant biomass for further enzymatic hydrolysis and fermentation stages. Two of the most employed pretreatment processes are the ones that used dilute acid (DA and alkaline (AL catalyst providing specific effects on the physicochemical structure of the biomass such as high xylan and lignin removal for DA and AL, respectively. Another important effect that need to be studied is the use of a high solids pretreatment (≥15% since offers many advantaged over lower solids loadings, including increased sugar and ethanol concentrations (in combination with a high solids saccharification which will be reflected in lower capital costs, however this data is currently limited. In this study, several variables such as catalyst loading, retention time and solids loading, were studied using Response Surface Methodology (RSM based on a factorial Central Composite Design (CCD of DA and AL pretreatment on agave bagasse using a range of solids from 3 to 30% (w/w to obtain optimal process conditions for each pretreatment. Subsequently enzymatic hydrolysis was performed using Novozymes Cellic CTec2 and HTec2 presented as total reducing sugar (TRS yield. Pretreated biomass

Enhanced bioprocessing of lignocellulose: Wood-rot fungal saccharification and fermentation of corn fiber to ethanol

Science.gov (United States)

Shrestha, Prachand

This research aims at developing a biorefinery platform to convert corn-ethanol coproduct, corn fiber, into fermentable sugars at a lower temperature with minimal use of chemicals. White-rot (Phanerochaete chrysosporium), brown-rot (Gloeophyllum trabeum) and soft-rot (Trichoderma reesei) fungi were used in this research to biologically break down cellulosic and hemicellulosic components of corn fiber into fermentable sugars. Laboratory-scale simultaneous saccharification and fermentation (SSF) process proceeded by in-situ cellulolytic enzyme induction enhanced overall enzymatic hydrolysis of hemi/cellulose from corn fiber into simple sugars (mono-, di-, tri-saccharides). The yeast fermentation of hydrolyzate yielded 7.1, 8.6 and 4.1 g ethanol per 100 g corn fiber when saccharified with the white-, brown-, and soft-rot fungi, respectively. The highest corn-to-ethanol yield (8.6 g ethanol/100 g corn fiber) was equivalent to 42 % of the theoretical ethanol yield from starch and cellulose in corn fiber. Cellulase, xylanase and amylase activities of these fungi were also investigated over a week long solid-substrate fermentation of corn fiber. G. trabeum had the highest activities for starch (160 mg glucose/mg protein.min) and on day three of solid-substrate fermentation. P. chrysosporium had the highest activity for xylan (119 mg xylose/mg protein.min) on day five and carboxymethyl cellulose (35 mg glucose/mg protein.min) on day three of solid-substrate fermentation. T. reesei showed the highest activity for Sigma cell 20 (54.8 mg glucose/mg protein.min) on day 5 of solid-substrate fermentation. The effect of different pretreatments on SSF of corn fiber by fungal processes was examined. Corn fiber was treated at 30 °C for 2 h with alkali [2% NaOH (w/w)], alkaline peroxide [2% NaOH (w/w) and 1% H2O 2 (w/w)], and by steaming at 100 °C for 2 h. Mild pretreatment resulted in improved ethanol yields for brown- and soft-rot SSF, while white-rot and Spezyme CP SSFs showed

Hydrolysis of Miscanthus for bioethanol production using dilute acid presoaking combined with wet explosion pre-treatment and enzymatic treatment

DEFF Research Database (Denmark)

Sørensen, Annette; Teller, Philip Johan; Hilstrøm, Troels

2008-01-01

xylose prior to wet explosion. The acid presoaking extracted 63.2% xylose and 5.2% glucose. Direct enzymatic hydrolysis of the presoaked biomass was found to give only low sugar yields of 24-26% glucose. Wet explosion is a pre-treatment method that combines wet-oxidation and steam explosion. The effect...... of wet explosion on non-presoaked and presoaked Miscanthus was investigated using both atmospheric air and hydrogen peroxide as the oxidizing agent. All wet explosion pre-treatments showed to have a disrupting effect on the lignocellulosic biomass, making the sugars accessible for enzymatic hydrolysis......Miscanthus is a high yielding bioenergy crop. In this study we used acid presoaking, wet explosion, and enzymatic hydrolysis to evaluate the combination of the different pre-treatment methods for bioethanol production with Miscanthus. Acid presoaking is primarily carried out in order to remove...

Comparison of amino acid digestibility coefficients for corn, corn gluten meal, and corn distillers dried grains with solubles (DDGS) among three different bioassays

Science.gov (United States)

The objective of this study was to determine standardized AA digestibility of corn, corn gluten meal (CGM) and three distillers dried grains with solubles (DDGS) using the precision-fed cecectomized rooster assay (PFR), the standardized ileal AA broiler chicken assay (SIAAD), and a newly developed p...

Catalytic conversion of xylose and corn stalk into furfural over carbon solid acid catalyst in γ-valerolactone.

Science.gov (United States)

Zhang, Tingwei; Li, Wenzhi; Xu, Zhiping; Liu, Qiyu; Ma, Qiaozhi; Jameel, Hasan; Chang, Hou-min; Ma, Longlong

2016-06-01

A novel carbon solid acid catalyst was synthesized by the sulfonation of carbonaceous material which was prepared by carbonization of sucrose using 4-BDS as a sulfonating agent. TEM, N2 adsorption-desorption, elemental analysis, XPS and FT-IR were used to characterize the catalyst. Then, the catalyst was applied for the conversion of xylose and corn stalk into furfural in GVL. The influence of the reaction time, temperature and dosage of catalyst on xylose dehydration were also investigated. The Brønsted acid catalyst exhibited high activity in the dehydration of xylose, with a high furfural yield of 78.5% at 170°C in 30min. What's more, a 60.6% furfural yield from corn stalk was achieved in 100min at 200°C. The recyclability of the sulfonated carbon catalyst was perfect, and it could be reused for 5times without the loss of furfural yields. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acid-functionalized nanoparticles for biomass hydrolysis

Science.gov (United States)

Pena Duque, Leidy Eugenia

Cellulosic ethanol is a renewable source of energy. Lignocellulosic biomass is a complex material composed mainly of cellulose, hemicellulose, and lignin. Biomass pretreatment is a required step to make sugar polymers liable to hydrolysis. Mineral acids are commonly used for biomass pretreatment. Using acid catalysts that can be recovered and reused could make the process economically more attractive. The overall goal of this dissertation is the development of a recyclable nanocatalyst for the hydrolysis of biomass sugars. Cobalt iron oxide nanoparticles (CoFe2O4) were synthesized to provide a magnetic core that could be separated from reaction using a magnetic field and modified to carry acid functional groups. X-ray diffraction (XRD) confirmed the crystal structure was that of cobalt spinel ferrite. CoFe2O4 were covered with silica which served as linker for the acid functions. Silica-coated nanoparticles were functionalized with three different acid functions: perfluoropropyl-sulfonic acid, carboxylic acid, and propyl-sulfonic acid. Transmission electron microscope (TEM) images were analyzed to obtain particle size distributions of the nanoparticles. Total carbon, nitrogen, and sulfur were quantified using an elemental analyzer. Fourier transform infra-red spectra confirmed the presence of sulfonic and carboxylic acid functions and ion-exchange titrations accounted for the total amount of catalytic acid sites per nanoparticle mass. These nanoparticles were evaluated for their performance to hydrolyze the beta-1,4 glycosidic bond of the cellobiose molecule. Propyl-sulfonic (PS) and perfluoropropyl-sulfonic (PFS) acid functionalized nanoparticles catalyzed the hydrolysis of cellobiose significantly better than the control. PS and PFS were also evaluated for their capacity to solubilize wheat straw hemicelluloses and performed better than the control. Although PFS nanoparticles were stronger acid catalysts, the acid functions leached out of the nanoparticle during

Dual effect of soluble materials in pretreated lignocellulose on simultaneous saccharification and co-fermentation process for the bioethanol production.

Science.gov (United States)

Qin, Lei; Li, Xia; Liu, Li; Zhu, Jia-Qing; Guan, Qi-Man; Zhang, Man-Tong; Li, Wen-Chao; Li, Bing-Zhi; Yuan, Ying-Jin

2017-01-01

In this study, wash liquors isolated from ethylenediamine and dry dilute acid pretreated corn stover were used to evaluate the effect of soluble materials in pretreated biomass on simultaneous saccharification and co-fermentation (SSCF) for ethanol production, respectively. Both of the wash liquors had different impacts on enzymatic hydrolysis and fermentation. Enzymatic conversions of glucan and xylan monotonically decreased as wash liquor concentration increased. Whereas, with low wash liquor concentrations, xylose consumption rate, cell viability and ethanol yield were maximally stimulated in fermentation without nutrient supplementary. Soluble lignins were found as the key composition which promoted sugars utilization and cell viability without nutrient supplementary. The dual effects of soluble materials on enzymatic hydrolysis and fermentation resulted in the reduction of ethanol yield as soluble materials increased in SSCF. Copyright © 2016 Elsevier Ltd. All rights reserved.

Cold pressed versus refined winterized corn oils: quality, composition and aroma

International Nuclear Information System (INIS)

Aydeniz Güneşer, B.; Yılmaz, E.; Ok, S.

2017-01-01

The aims of this study were to characterize and compare cold pressed and fully refined winterized corn oils. Free fatty acidity (FFA), peroxide (PV) and p-anisidin (p-AV) values, saponification number, total carotenoid and phenolic contents of cold pressed corn oils were higher than that of the refined winterized corn oils. Linoleic and oleic acids (approximately 53-54% and 30-31%, respectively) were detected as the major fatty acids in both oil samples. Fifteen different sterols with a majority of β-sitosterol, campesterol, and stigmasterol were quantified in both oil samples. Although phenolic compounds were not quantified in the refined winterized oil samples, some flavonoids (hesperidin, rutin) and phenolic acids (gallic, syringic, rosmaniric and trans-ferulic) were detected in the cold pressed oil samples. This study concludes that cold pressed corn oils could be superior in terms of bioactive compounds but still need some quality improvements for sensory attributes. [es

Stochastic Corn Yield Response Functions to Nitrogen for Corn after Corn, Corn after Cotton, and Corn after Soybeans

OpenAIRE

Boyer, Christopher N.; Larson, James A.; Roberts, Roland K.; McClure, Angela T.; Tyler, Donald D.; Zhou, Vivian

2013-01-01

Deterministic and stochastic yield response plateau functions were estimated to determine the expected profit-maximizing nitrogen rates, yields, and net returns for corn grown after corn, cotton, and soybeans. The stochastic response functions were more appropriate than their deterministic counterparts, and the linear response stochastic plateau described the data the best. The profit-maximizing nitrogen rates were similar for corn after corn, cotton, and soybeans, but relative to corn after ...

The effect of pretreatment using sodium hydroxide and acetic acid to biogas production from rice straw waste

Directory of Open Access Journals (Sweden)

Budiyono

2017-01-01

Full Text Available Rice straw is agricultural waste containing high potency to be treated to biogas. However, the usage of rice straw is still limited due to high lignin content that will cause low biodegradability. The aim of this research was to study the effect of pretreatment using NaOH and acetic acid to biogas production from rice straw. NaOH was varied from 2%w, 4%w, and 6%w; and acetic acid was varied from 0,075 M, 0,15 M dan 0,75 M. The rice straw was cut into 1 cm size and submerged for 30 minutes in NaOH and acetic acid solution. The rice straw then filtered and neutralized before sending to anaerobic digestion process using rumen fluid bacteria. Biogas produced was measured using water displacement method. The result showed that the optimum concentration of NaOH solution was 4%w that resulted in biogas volume of 21,1 ml/gTS. Meanwhile, the optimum concentration of acetic acid pretreatment was 0,075 M that produced biogas volume of 14,5 ml/gTS. These results suggest that pretreatment using NaOH solution is more effective for decreasing the lignin content from rice straw.

Blending municipal solid waste with corn stover for sugar production using ionic liquid process

Energy Technology Data Exchange (ETDEWEB)

Sun, Ning [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Xu, Feng [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Sathitsuksanoh, Noppadon [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Thompson, Vicki S. [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Cafferty, Kara [Idaho National Laboratory (INL), Idaho Falls, ID (United States); Li, Chenlin [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Tanjore, Deepti [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Narani, Akash [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Pray, Todd R. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Simmons, Blake A. [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States); Singh, Seema [Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States); Sandia National Laboratories (SNL-CA), Livermore, CA (United States)

2015-06-01

Municipal solid waste (MSW) represents an attractive cellulosic resource for sustainable fuel production because of its abundance and its low or perhaps negative cost. However, the significant heterogeneity and toxic contaminants are barriers to efficient conversion to ethanol and other products. In this study, we generated MSW paper mix, blended with corn stover (CS), and have shown that both MSW paper mix alone and MSW/CS blends can be efficiently pretreated in certain ionic liquids (ILs) with high yields of fermentable sugars. After pretreatment in 1-ethyl-3-methylimidazolium acetate ([C₂C₁Im][OAc]), over 80% glucose has been released with enzymatic saccharification. We have also applied an enzyme free process by adding mineral acid and water directly into the IL/biomass slurry to induce hydrolysis. With the acidolysis process in the IL 1-ethyl-3-methylimidazolium chloride ([C₂C₁Im]Cl), up to 80% glucose and 90% xylose are released for MSW. The results indicate the feasibility of incorporating MSW as a robust blending agent for biorefineries.

Effectiveness of Alkaline Pretreatment and Acetic Acid Hydrolysis on the Characteristics of Collagen from Fish Skin of Snakehead

Directory of Open Access Journals (Sweden)

Wulandari

2015-12-01

Full Text Available Fish skin is one of marine byproducts potential for alternative source of collagen. This study investigated the effectiveness of alkaline and acetic acid pretreatment on the characteristics of collagen from skin snakehead fish. The concentrations of alkaline pretreatment were 0.05; 0.1; 0.15 and 0.2 M for 2, 4, 6, 8, 10 and 12 hours, acetic acid concentrations were 0.05 M, 0.1 M, 0.15 M and 0.2 M for 1 and 2 hours. The experimental design used for alkaline and acetic acid pretreatment was factorial completely randomized design. The result showed that the concentration of alkaline 0.05 M for 6 hours have significant effect on the elimination of non-collagen protein (p<0.05, whereas for the optimum acetic acid at a concentration 0.1 M for 2 hours significantly different on solubility and swelling. Extraction yields of collagen was 16%, with characteristics of whiteness 66.67%, protein content 96.21%, viscosity 10 cP, Tmax 159.9oC and glass transition temperature 78.55oC. The dominant amino acid composition were glycine (27.11%, proline (13.87% and alanine (12.58%. Functional groups collagen from skin snakehead fish has β-sheet structure which is a characteristic of collagen.

Comparing oxidative and dilute acid wet explosion pretreatment of Cocksfoot grass at high dry matter concentration for cellulosic ethanol production

DEFF Research Database (Denmark)

Njoku, Stephen Ikechukwu; Uellendahl, Hinrich; Ahring, Birgitte Kiær

2013-01-01

into cellulose monomeric C6 sugars was achieved for WEx condition AC-E (180°C, 15 min, and 0.2% sulfuric acid). For that condition, the highest ethanol yield of 197 g/kg DM (97% of theoretical maximum value) was achieved for SSF process by Saccharomyces cerevisiae. However, the highest concentration...... of hemicellulose C5 sugars was found for WEx pretreatment condition O2-A (160°C, 15 min, and 6 bar O2) which means that the highest potential ethanol yield was found at this moderate pretreatment condition with oxygen added. Increasing the pretreatment temperature to 180–190°C with addition of oxygen or dilute...... was investigated for cellulosic ethanol production. The biomass raw materials were pretreated using wet explosion (WEx) at 25% dry matter concentration with addition of oxygen or dilute sulfuric acid. The enzymatic hydrolysis of cellulose was significantly improved after pretreatment. The highest conversion...

Impact of acid and alkaline pretreatments on the molecular network of wheat gluten and on the mechanical properties of compression-molded glassy wheat gluten bioplastics.

Science.gov (United States)

Jansens, Koen J A; Lagrain, Bert; Brijs, Kristof; Goderis, Bart; Smet, Mario; Delcour, Jan A

2013-10-02

Wheat gluten can be converted into rigid biobased materials by high-temperature compression molding at low moisture contents. During molding, a cross-linked protein network is formed. This study investigated the effect of mixing gluten with acid/alkali in 70% ethanol at ambient temperature for 16 h followed by ethanol removal, freeze-drying, and compression molding at 130 and 150 °C on network formation and on types of cross-links formed. Alkaline pretreatment (0-100 mmol/L sodium hydroxide or 25 mmol/L potassium hydroxide) strongly affected gluten cross-linking, whereas acid pretreatment (0-25 mmol/L sulfuric acid or 25 mmol/L hydrochloric acid) had limited effect on the gluten network. Molded alkaline-treated gluten showed enhanced cross-linking but also degradation when treated with high alkali concentrations, whereas acid treatment reduced gluten cross-linking. β-Elimination of cystine and lanthionine formation occurred more pronouncedly at higher alkali concentrations. In contrast, formation of disulfide and nondisulfide cross-links during molding was hindered in acid-pretreated gluten. Bioplastic strength was higher for alkali than for acid-pretreated samples, whereas the flexural modulus was only slightly affected by either alkaline or acid pretreatment. Apparently, the ratio of disulfide to nondisulfide cross-links did not affect the mechanical properties of rigid gluten materials.

Physicochemical and sensory qualities of spiced soy-corn milk ...

African Journals Online (AJOL)

Soy-corn milk type was produced from a blend of soybean milk and corn milk extract at a ratio of 3:1. The soy-corn milk type was spiced with ginger and garlic extract respectively to improve the taste. Total dissolved solid (TDS), total titrable acidity (TTA) specific gravity (SG), apparent colloidal stability, pH and sensory ...

Comparison and Optimization of Saccharification Conditions of Alkaline Pre-Treated Triticale Straw for Acid and Enzymatic Hydrolysis Followed by Ethanol Fermentation

Directory of Open Access Journals (Sweden)

Rafał Łukajtis

2018-03-01

Full Text Available This paper concerns the comparison of the efficiency of two-stage hydrolysis processes, i.e., alkaline pre-treatment and acid hydrolysis, as well as alkaline pre-treatment followed by enzymatic hydrolysis, carried out in order to obtain reducing sugars from triticale straw. For each of the analyzed systems, the optimization of the processing conditions was carried out with respect to the glucose yield. For the alkaline pre-treatment, an optimal catalyst concentration was selected for constant values of temperature and pre-treatment time. For enzymatic hydrolysis, optimal process time and concentration of the enzyme preparation were determined. For the acidic hydrolysis, performed with 85% phosphoric acid, the optimum temperature and hydrolysis time were determined. In the hydrolysates obtained after the two-stage treatment, the concentration of reducing sugars was determined using HPLC. The obtained hydrolysates were subjected to ethanol fermentation. The concentrations of fermentation inhibitors are given and their effects on the alcoholic fermentation efficiency are discussed.

Optimizing peracetic acid pretreatment conditions for improved simultaneous saccharification and co-fermentation (SSCF) of sugar cane bagasse to ethanol fuel

Energy Technology Data Exchange (ETDEWEB)

Teixeira, Lincoln C. [Fundacao Centro Tecnologico de Minas Gerais, Setor de Biotecnologia e Tecnologia Quimica, Minas Geraid (Brazil); Linden, James C.; Schroeder, Herbert A. [Colorado State Univ., Dept. of Chemical and Bioresource Engineering, Fort Collins, CO (United States)

1999-01-01

The use of several lignocellulosic materials for ethanol fuel production has been studied exhaustively in the U.S.A. Strong environmental legislation has been driving efforts by enterprise, state agencies, and universities to make ethanol from biomass economically viable. Production costs for ethanol from biomass have been decreasing year by year as a consequence of this massive effort. Pretreatment, enzyme recovery, and development of efficient microorganisms are some promising areas of study for reducing process costs. Sugar cane bagasse constitutes the most important lignocellulosic material to be considered in Brazil as new technology such as the production of ethanol fuel. At present, most bagasse is burned, and because of its moisture content, has a low value fuel. Ethanol production would result in a value-added product. The bagasse is available at the sugar mill site at no additional cost because harvesting, transportation and storage costs are borne by the sugar production. The present paper presents an alternative pretreatment with low energy input where biomass is treated in a silo type system without need for expensive capitalisation. Experimentally, ground sugar cane bagasse is placed in plastic bags and a peracetic acid solution is added to the biomass at concetrations of 0, 6, 9, 15, 21, 30 and 60% w/w of peracetic acid based on over dried biomass. The ratio of solution to wood is 6:1; a seven day storage period had been used. Tests using hydrolysing enzymes as an indicator for SSCF have been performed to evaluated the pretreatment efficiency. As an auxiliary method, a series of pre-pretreatments using stoichiometric amounts of sodium hydroxide and ammonium hydroxide based on 4-methyl-glucuronic acid and acetate content in the sugar cane bagasse have been performed before addition of peracetic acid. The alkaline solutions are added to the raw bagasse in a ratio of 17:1 solution to biomass and mixed for 24 hours at room temperature. Biomass is filled

Uptake and phytotoxicity of the herbicide metsulfuron methyl in corn root tissue in the presence of the safener 1,8-naphthalic anhydride

International Nuclear Information System (INIS)

Milhomme, H.; Bastide, J.

1990-01-01

Growth of Zea mays L. cv Potro roots was inhibited by the herbicide metsulfuron methyl (MSM) at the lowest concentration tested: 5 nanomoles per liter. Pretreatment of corn seeds with commercial 1,8-naphthalic anhydride (NA) at 1% (w/w) partially reversed MSM-induced root growth inhibition. MSM at a concentration of 52 nanomoles per liter was taken up rapidly by roots and accumulated in the corn tissue to concentrations three times those in the external medium; the safener NA increased MSM uptake up to 48 hours. The protective effect of NA was related to the ability of the safener to increase the metabolism of MSM; ten-fold increases in the metabolic rates of MSM were observed in NA-pretreated corn seedlings grown for 48 hours on 52 nanomolar [ 14 C]MSM solution. DNA synthesis determined by measurement of [ 3 H]thymidine incorporation into DNA was inhibited by root MSM applications; after a 6-hour application period, 13 nanomolar MSM solution reduced DNA synthesis by 64%, and the same reduction was also observed with NA-treated seedlings. Pretreatment of corn seeds with safener NA did not increase the acetolactate synthase activity in the roots and did not change, up to 13 micromoles per liter, the in vitro sensitivity of roots to MSM

Techno-economic analysis of organosolv pretreatment process from lignocellulosic biomass

DEFF Research Database (Denmark)

Rodrigues Gurgel da Silva, Andrè; Errico, Massimiliano; Rong, Ben-Guang

2018-01-01

data, we propose a feasible process flowsheet for organosolv pretreatment. Simulation of the pretreatment process provided mass and energy balances for a techno-economic analysis, and the values were compared with the most prevalent and mature pretreatment method: diluted acid. Organosolv pretreatment...... required more energy, 578.1 versus 213.8 MW for diluted acid pretreatment, but resulted in a higher ethanol concentration after the biomass fermentation, 11.1% compared to 5.4%. Total annual costs (TACs) calculations showed advantages for diluted acid pretreatment, but future improvements explored...

Study on loading coefficient in steam explosion process of corn stalk.

Science.gov (United States)

Sui, Wenjie; Chen, Hongzhang

2015-03-01

The object of this work was to evaluate the effect of loading coefficient on steam explosion process and efficacy of corn stalk. Loading coefficient's relation with loading pattern and material property was first revealed, then its effect on transfer process and pretreatment efficacy of steam explosion was assessed by established models and enzymatic hydrolysis tests, respectively, in order to propose its optimization strategy for improving the process economy. Results showed that loading coefficient was mainly determined by loading pattern, moisture content and chip size. Both compact loading pattern and low moisture content improved the energy efficiency of steam explosion pretreatment and overall sugar yield of pretreated materials, indicating that they are desirable to improve the process economy. Pretreatment of small chip size showed opposite effects in pretreatment energy efficiency and enzymatic hydrolysis performance, thus its optimization should be balanced in investigated aspects according to further techno-economical evaluation. Copyright © 2014 Elsevier Ltd. All rights reserved.

Disruption of sugarcane bagasse lignocellulosic structure by means of dilute sulfuric acid pretreatment with microwave-assisted heating

International Nuclear Information System (INIS)

Chen, Wei-Hsin; Tu, Yi-Jian; Sheen, Herng-Kuang

2011-01-01

Highlights: → Pretreatment of dilute sulfuric acid on bagasse using microwave heating. → An increase in reaction temperature destroyed bagasse significantly. → Pretreated bagasse particles were characterized by fragmentation and swelling. → When the temperature was 190 o C, the fragmentation of particles became pronounced. → The influence of heating time on bagasse structure was not significant. - Abstract: Disruption of lignocellulosic structure of biomass plays a key role in producing bioethanol from lignocelluloses. This study investigated the impact of dilute sulfuric acid pretreatment on bagasse structure using microwave heating. Three reaction temperatures of 130, 160 and 190 o C with two heating times of 5 and 10 min were considered and a number of instruments were employed to analyze the properties of the bagasse particles. On account of microwave irradiation into the solution with dielectric heating, the experiments indicated that an increase in reaction temperature destroyed the lignocellulosic structure of bagasse in a significant way. The pretreated bagasse particles were simultaneously characterized by fragmentation and swelling. When the reaction temperature was as high as 190 o C, the fragmentation of particles became fairly pronounced so that the specific surface area of the pretreated material grew substantially. Meanwhile, almost all hemicellulose was removed from bagasse and the crystalline structure of cellulose disappeared. In contrast, the feature of lignin was remained clearly. However, a comparison between the heating times of 5 and 10 min revealed that the influence of the heating time on the lignocellulosic structure was not significant, indicating that the pretreatment with 5 min was sufficiently long.

Assessment of hydrothermal pretreatment of various lignocellulosic biomass with CO2 catalyst for enhanced methane and hydrogen production.

Science.gov (United States)

Eskicioglu, Cigdem; Monlau, Florian; Barakat, Abdellatif; Ferrer, Ivet; Kaparaju, Prasad; Trably, Eric; Carrère, Hélène

2017-09-01

Hydrothermal pretreatment of five lignocellulosic substrates (i.e. wheat straw, rice straw, biomass sorghum, corn stover and Douglas fir bark) were conducted in the presence of CO 2 as a catalyst. To maximize disintegration and conversion into bioenergy (methane and hydrogen), pretreatment temperatures and subsequent pressures varied with a range of 26-175 °C, and 25-102 bars, respectively. Among lignin, cellulose and hemicelluloses, hydrothermal pretreatment caused the highest reduction (23-42%) in hemicelluloses while delignification was limited to only 0-12%. These reductions in structural integrity resulted in 20-30% faster hydrolysis rates during anaerobic digestion for the pretreated substrates of straws, sorghum, and corn stover while Douglas fir bark yielded 172% faster hydrolysis/digestion due to its highly refractory nature in the control. Furans and phenolic compounds formed in the pretreated hydrolyzates were below the inhibitory levels for methane and hydrogen production which had a range of 98-340 ml CH 4 /g volatile solids (VS) and 5-26 ml H 2 /g VS, respectively. Results indicated that hydrothermal pretreatment is able to accelerate the rate of biodegradation without generating high levels of inhibitory compounds while showing no discernible effect on ultimate biodegradation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phosphoric acid pretreatment of Achyranthes aspera and Sida acuta weed biomass to improve enzymatic hydrolysis.

Science.gov (United States)

Siripong, Premjet; Duangporn, Premjet; Takata, Eri; Tsutsumi, Yuji

2016-03-01

Achyranthes aspera and Sida acuta, two types of weed biomass are abundant and waste in Thailand. We focus on them as novel feedstock for bio-ethanol production because they contain high-cellulose content (45.9% and 46.9%, respectively) and unutilized material. Phosphoric acid (70%, 75%, and 80%) was employed for the pretreatment to improve by enzymatic hydrolysis. The pretreatment process removed most of the xylan and a part of the lignin from the weeds, while most of the glucan remained. The cellulose conversion to glucose was greater for pretreated A. aspera (86.2 ± 0.3%) than that of the pretreated S. acuta (82.2 ± 1.1%). Thus, the removal of hemicellulose significantly affected the efficiency of the enzymatic hydrolysis. The scanning electron microscopy images showed the exposed fibrous cellulose on the cell wall surface, and this substantial change of the surface structure contributed to improving the enzyme accessibility. Copyright © 2015 Elsevier Ltd. All rights reserved.

Over production of fermentable sugar for bioethanol production from carbohydrate-rich Malaysian food waste via sequential acid-enzymatic hydrolysis pretreatment.

Science.gov (United States)

Hafid, Halimatun Saadiah; Nor 'Aini, Abdul Rahman; Mokhtar, Mohd Noriznan; Talib, Ahmad Tarmezee; Baharuddin, Azhari Samsu; Umi Kalsom, Md Shah

2017-09-01

In Malaysia, the amount of food waste produced is estimated at approximately 70% of total municipal solid waste generated and characterised by high amount of carbohydrate polymers such as starch, cellulose, and sugars. Considering the beneficial organic fraction contained, its utilization as an alternative substrate specifically for bioethanol production has receiving more attention. However, the sustainable production of bioethanol from food waste is linked to the efficient pretreatment needed for higher production of fermentable sugar prior to fermentation. In this work, a modified sequential acid-enzymatic hydrolysis process has been developed to produce high concentration of fermentable sugars; glucose, sucrose, fructose and maltose. The process started with hydrothermal and dilute acid pretreatment by hydrochloric acid (HCl) and sulphuric acid (H 2 SO 4 ) which aim to degrade larger molecules of polysaccharide before accessible for further steps of enzymatic hydrolysis by glucoamylase. A kinetic model is proposed to perform an optimal hydrolysis for obtaining high fermentable sugars. The results suggested that a significant increase in fermentable sugar production (2.04-folds) with conversion efficiency of 86.8% was observed via sequential acid-enzymatic pretreatment as compared to dilute acid pretreatment (∼42.4% conversion efficiency). The bioethanol production by Saccharomyces cerevisiae utilizing fermentable sugar obtained shows ethanol yield of 0.42g/g with conversion efficiency of 85.38% based on the theoretical yield was achieved. The finding indicates that food waste can be considered as a promising substrate for bioethanol production. Copyright © 2017. Published by Elsevier Ltd.

Butyric acid fermentation from pre-treated wheat straw by a mutant clostridium tyrobutyricum strain

DEFF Research Database (Denmark)

Baroi, George Nabin; Baumann, Ivan; Westermann, Peter

Only little research on butyric acid fermentation has been carried out in relationship to bio-refinery perspectives involving strain selection, development of adapted strains, physiological analyses for higher yield, productivity and selectivity. However, a major step towards the development...... strain could grow in up to 80% pre-treated wheat straw and can ferment both glucose and xylose. The yield of butyric acid without optimization was 0,37±0,051 g butyric acid/g sugar monomers and the acetate yield was 0,06±0,021 g acetic acid/g sugar monomers. Moreover, the strain could grow without...... addition of yeast extract. Further optimization of yield and productivity is under investigation....

Feasibility of enhancing short-chain fatty acids production from sludge anaerobic fermentation at free nitrous acid pretreatment: Role and significance of Tea saponin.

Science.gov (United States)

Xu, Qiuxiang; Liu, Xuran; Zhao, Jianwei; Wang, Dongbo; Wang, Qilin; Li, Xiaoming; Yang, Qi; Zeng, Guangming

2018-04-01

Short-chain fatty acids (SCFA), raw substrates for biodegradable plastic production and preferred carbon source for biological nutrients removal, can be produced from anaerobic fermentation of waste activated sludge (WAS). This paper reports a new, high-efficient and eco-friendly strategy, i.e., using free nitrous acid (FNA) pretreatment combined with Tea saponin (TS), to enhance SCFA production. Experimental results showed 0.90 mg/L FNA pretreatment and 0.05 g/g total suspended solids TS addition (FNA + TS) not only significantly increased SCFA production to 315.3 ± 8.8 mg COD/g VSS (5.52, 1.76 and 1.93 times higher than that from blank, solo FNA and solo TS, respectively) but also shortened fermentation time to 4 days. Mechanism investigations revealed that FNA pretreatment combined with TS cause a positive synergetic effect on sludge solubilization, resulting in more release of organics. It was also found that the combination benefited hydrolysis and acidogenesis processes but inhibited the methanogenesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

Citric acid production from hydrolysate of pretreated straw cellulose by Yarrowia lipolytica SWJ-1b using batch and fed-batch cultivation.

Science.gov (United States)

Liu, Xiaoyan; Lv, Jinshun; Zhang, Tong; Deng, Yuanfang

2015-01-01

In this study, crude cellulase produced by Trichoderma reesei Rut-30 was used to hydrolyze pretreated straw. After the compositions of the hydrolysate of pretreated straw were optimized, the study showed that natural components of pretreated straw without addition of any other components such as (NH4)2SO4, KH2PO4, or Mg(2+) were suitable for citric acid production by Yarrowia lipolytica SWJ-1b, and the optimal ventilatory capacity was 10.0 L/min/L medium. Batch and fed-batch production of citric acid from the hydrolysate of pretreated straw by Yarrowia lipolytica SWJ-1b has been investigated. In the batch cultivation, 25.4 g/L and 26.7 g/L citric acid were yields from glucose and hydrolysate of straw cellulose, respectively, while the cultivation time was 120 hr. In the three-cycle fed-batch cultivation, citric acid (CA) production was increased to 42.4 g/L and the cultivation time was extended to 240 hr. However, iso-citric acid (ICA) yield in fed-batch cultivation (4.0 g/L) was similar to that during the batch cultivation (3.9 g/L), and only 1.6 g/L of reducing sugar was left in the medium at the end of fed-batch cultivation, suggesting that most of the added carbon was used in the cultivation.

BSA treatment to enhance enzymatic hydrolysis of cellulose in lignin containing substrates.

Science.gov (United States)

Yang, Bin; Wyman, Charles E

2006-07-05

Cellulase and bovine serum albumin (BSA) were added to Avicel cellulose and solids containing 56% cellulose and 28% lignin from dilute sulfuric acid pretreatment of corn stover. Little BSA was adsorbed on Avicel cellulose, while pretreated corn stover solids adsorbed considerable amounts of this protein. On the other hand, cellulase was highly adsorbed on both substrates. Adding a 1% concentration of BSA to dilute acid pretreated corn stover prior to enzyme addition at 15 FPU/g cellulose enhanced filter paper activity in solution by about a factor of 2 and beta-glucosidase activity in solution by about a factor of 14. Overall, these results suggested that BSA treatment reduced adsorption of cellulase and particularly beta-glucosidase on lignin. Of particular note, BSA treatment of pretreated corn stover solids prior to enzymatic hydrolysis increased 72 h glucose yields from about 82% to about 92% at a cellulase loading of 15 FPU/g cellulose or achieved about the same yield at a loading of 7.5 FPU/g cellulose. Similar improvements were also observed for enzymatic hydrolysis of ammonia fiber explosion (AFEX) pretreated corn stover and Douglas fir treated by SO(2) steam explosion and for simultaneous saccharification and fermentation (SSF) of BSA pretreated corn stover. In addition, BSA treatment prior to hydrolysis reduced the need for beta-glucosidase supplementation of SSF. The results are consistent with non-specific competitive, irreversible adsorption of BSA on lignin and identify promising strategies to reduce enzyme requirements for cellulose hydrolysis. (c) 2006 Wiley Periodicals, Inc.

Effect of oxalic acid pretreatment of wood chips on manufacturing medium-density fiberboard

Science.gov (United States)

Xianjun Li; Zhiyong Cai; Eric Horn; Jerrold E. Winandy

2011-01-01

The main objective of this study was to evaluate the effect of oxalic acid (OA) wood chips pretreatment prior to refining, which is done to reduce energy used during the refining process. Selected mechanical and physical performances of medium-density fiberboard (MDF) – internal bonding (IB), modulus of elasticity (MOE), modulus of rupture (MOR), water absorption (WA)...

[Corn.

Science.gov (United States)

Iowa History for Young People, 1993

1993-01-01

This theme issue focuses on corn. Iowa is the number one corn producing state in the United States. The featured articles in the issue concern, among other topics, Iowa children who live on farms, facts and statistics about corn, the Mesquakie Indians and corn shelling, corn hybrids, a short story, and the corn palaces of Sioux City. Activities,…

Effects of Pretreatment with Salicylic Acid on Growth and Nutrient Uptake of Sesame Seedlings under Salt Stress

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H Safari

2018-02-01

Full Text Available Introduction Salinity stress is regarded as one of the most important abiotic factors limiting plant growth and agricultural products, particularly in arid and semi-arid regions. Sesame (Sesamum indicum L. is an important oilseed crop rated moderately salt tolerant and capable of producing profitable crops in saline conditions. Germination and seedling establishment are critical stages in the life cycle of plants especially under stress conditions. Different methodologies have been adopted by plant physiologists in different crops to alleviate salt stress. Seed priming has proven beneficial in this regard in many important agricultural crops. Salicylic acid is one of the physiological processes regulators that it increases resistant of plants to environmental stresses such as salinity stress. Materials and Methods To evaluate the effect of different levels of salinity and seed pretreatment with salicylic acid (SA, on some growth indices and nutrient uptake of sesame (Sesamum indicum L. seedling, a factorial experiment with completely randomized design and four replicates was conducted in Department of Agronomy, Rafsanjan University of Vali-e- Asr. Factors were seed pretreatment with three levels including, distilled water, 1 mM salicylic acid and 2.5 Mm salicylic acid and salinity at three levels: control (Hoagland standard solution, 2.5 dS.m-1, 6 and 9 dS.m-1. A dry seed treatment (no pretreatment was also added and considered as control. Results and Discussion Results showed that at 9 dS/m-1both SA concentrations caused significant increase in emergence percentage compared to dry seed and distilled water. Plant leaf area and SPAD values decreased along with salinity in dry seed and distilled water, nevertheless, at 2.5 mM SA, values were not significantly different between 6 and 9 dS.m-1. On the other hand, SA seed pretreatment decreased shoot Na and increased K content, although shoot Mg and P contents were the highest at 1 and 2.5 mM SA

Studies on inhibition characteristics of corn steep liquor and black sulphite liquor on corrosion of mild steel in acid media

Energy Technology Data Exchange (ETDEWEB)

Deb, P C; Mukherjea, R N

1968-06-01

The purpose of this study was to economically reduce the attack by acid on the parent metal, during the process of removing mill scale by acid pickling. Two inhibitors, by-products of the starch industry and pulp industry, were studied due to their cheapness and availability in India. The inhibition efficiency of the corn steep liquor and black sulfite liquor was found to be below that of thiourea. For example, in 6.2% (w/w) H/sub 2/SO/sub 4/ (at 50/sup 0/C), an inhibition efficiency of 90.5% and 84.5% is reached for inhibitor concentrations of 10 g per liter in the case of corn steep liquor and black sulfite liquor, respectively, while a concentration of 0.25 g per liter of thiourea was required to reach an inhibition efficiency of 98.6%.

Heterologous Acidothermus cellulolyticus 1,4-β-Endoglucanase E1 Produced Within the Corn Biomass Converts Corn Stover Into Glucose

Science.gov (United States)

Ransom, Callista; Balan, Venkatesh; Biswas, Gadab; Dale, Bruce; Crockett, Elaine; Sticklen, Mariam

Commercial conversion of lignocellulosic biomass to fermentable sugars requires inexpensive bulk production of biologically active cellulase enzymes, which might be achieved through direct production of these enzymes within the biomass crops. Transgenic corn plants containing the catalytic domain of Acidothermus cellulolyticus E1 endo-1,4-β glucanase and the bar bialaphos resistance coding sequences were generated after Biolistic® (BioRad Hercules, CA) bombardment of immature embryo-derived cells. E1 sequences were regulated under the control of the cauliflower mosaic virus 35S promoter and tobacco mosaic virus translational enhancer, and E1 protein was targeted to the apoplast using the signal peptide of tobacco pathogenesis-related protein to achieve accumulation of this enzyme. The integration, expression, and segregation of E1 and bar transgenes were demonstrated, respectively, through Southern and Western blotting, and progeny analyses. Accumulation of up to 1.13% of transgenic plant total soluble proteins was detected as biologically active E1 by enzymatic activity assay. The corn-produced, heterologous E1 could successfully convert ammonia fiber explosion-pretreated corn stover polysaccharides into glucose as a fermentable sugar for ethanol production, confirming that the E1 enzyme is produced in its active from.

Microbial inoculant effects on silage and in vitro ruminal fermentation, and microbial biomass estimation for alfalfa, bmr corn, and corn silages

Science.gov (United States)

Third cut alfalfa, brown mid-rib (bmr) corn, and corn were chopped and inoculated with one of four different strains of lactic acid bacteria (LAB). Uninoculated silage was the control treatment. For each crop, four mini-silos 1-L glass jars were ensiled per treatment. All silos were fermented for 60...

Aromatic inhibitors derived from ammonia-pretreated lignocellulose hinder bacterial ethanologenesis by activating regulatory circuits controlling inhibitor efflux and detoxification

Directory of Open Access Journals (Sweden)

David H. Keating

2014-08-01

Full Text Available Efficient microbial conversion of lignocellulosic hydrolysates to biofuels is a key barrier to the economically viable deployment of lignocellulosic biofuels. A chief contributor to this barrier is the impact on microbial processes and energy metabolism of lignocellulose-derived inhibitors, including phenolic carboxylates, phenolic amides (for ammonia-pretreated biomass, phenolic aldehydes, and furfurals. To understand the bacterial pathways induced by inhibitors present in ammonia-pretreated biomass hydrolysates, which are less well studied than acid-pretreated biomass hydrolysates, we developed and exploited synthetic mimics of ammonia-pretreated corn stover hydrolysate (ACSH. To determine regulatory responses to the inhibitors normally present in ACSH, we measured transcript and protein levels in an Escherichia coli ethanologen using RNA-seq and quantitative proteomics during fermentation to ethanol of synthetic hydrolysates containing or lacking the inhibitors. Our study identified four major regulators mediating these responses, the MarA/SoxS/Rob network, AaeR, FrmR, and YqhC. Induction of these regulons was correlated with a reduced rate of ethanol production, buildup of pyruvate, depletion of ATP and NAD(PH, and an inhibition of xylose conversion. The aromatic aldehyde inhibitor 5-hydroxymethylfurfural appeared to be reduced to its alcohol form by the ethanologen during fermentation, whereas phenolic acid and amide inhibitors were not metabolized. Together, our findings establish that the major regulatory responses to lignocellulose-derived inhibitors are mediated by transcriptional rather than translational regulators, suggest that energy consumed for inhibitor efflux and detoxification may limit biofuel production, and identify a network of regulators for future synthetic biology efforts.

Fast pyrolysis of corn stover using ZnCl2: Effect of washing treatment on the furfural yield and solvent extraction of furfural

International Nuclear Information System (INIS)

Oh, Seung-Jin; Choi, Gyung-Goo; Kim, Joo-Sik

2015-01-01

To produce a bio-oil having a high concentration of furfural, corn stover was fast-pyrolyzed using ZnCl 2 in a fluidized bed reactor at 330–430 °C. The effects of various parameters such as reaction temperature, water- and acid-washing prior to pyrolysis, and ZnCl 2 content on the product and furfural yields were investigated. Moreover, solvent extraction was conducted using toluene at different mass ratios of bio-oil/toluene to recover furfural from the obtained bio-oil. The maximum yield of bio-oil was 59 wt%. The bio-oil mainly comprised acetic acid, α-hydroxyketones, and furfural. The maximum furfural yield was 11.5 wt% when the feed material was water-washed, impregnated with 18.5 wt% ZnCl 2 , and pyrolyzed. Although acid-washing removed alkali and alkaline earth metals much more efficiently than water-washing, water-washing was better than acid-washing for the furfural production. Toluene extraction was very effective to recover furfural from bio-oil. The maximum recovery rate (82%) was achieved at a bio-oil/toluene ratio of 1:4. - Highlights: • Corn stover pretreated and impregnated with ZnCl 2 was successfully pyrolyzed. • Furfural was recovered from bio-oil by extraction using toluene. • Water-washing was better than acid-washing for the furfural production. • The highest furfural yield was 11.5 wt% of the product. • The highest furfural recovery rate was 82%

Powerful peracetic acid-ionic liquid pretreatment process for the efficient chemical hydrolysis of lignocellulosic biomass.

Science.gov (United States)

Uju; Goto, Masahiro; Kamiya, Noriho

2016-08-01

The aim of this work was to design a new method for the efficient saccharification of lignocellulosic biomass (LB) using a combination of peracetic acid (PAA) pretreatment with ionic liquid (IL)-HCl hydrolysis. The pretreatment of LBs with PAA disrupted the lignin fractions, enhanced the dissolution of LB and led to a significant increase in the initial rate of the IL-HCl hydrolysis. The pretreatment of Bagasse with PAA prior to its 1-buthyl-3-methylimidazolium chloride ([Bmim][Cl])-HCl hydrolysis, led to an improvement in the cellulose conversion from 20% to 70% in 1.5h. Interestingly, the 1-buthyl-3-methylpyridium chloride ([Bmpy][Cl])-HCl hydrolysis of Bagasse gave a cellulose conversion greater than 80%, with or without the PAA pretreatment. For LB derived from seaweed waste, the cellulose conversion reached 98% in 1h. The strong hydrolysis power of [Bmpy][Cl] was attributed to its ability to transform cellulose I to II, and lowering the degree of polymerization of cellulose. Copyright © 2016 Elsevier Ltd. All rights reserved.

Starch Spherulites Prepared by a Combination of Enzymatic and Acid Hydrolysis of Normal Corn Starch.

Science.gov (United States)

Shang, Yaqian; Chao, Chen; Yu, Jinglin; Copeland, Les; Wang, Shuo; Wang, Shujun

2018-06-13

This paper describes a new method to prepare spherulites from normal corn starch by a combination of enzymatic (mixtures of α-amylase and amyloglucosidase) and acid hydrolysis followed by recrystallization of the hydrolyzed products. The resulting spherulites contained a higher proportion of chains with a degree of polymerization (DP) of 6-12 and a lower proportion of chains with DP of 25-36, compared to those of native starch. The spherulites had an even particle size of about 2 μm and a typical B-type crystallinity. The amounts of long- and short-range molecular order of double helices in starch spherulites were larger, but the quality of starch crystallites was poorer, compared to that of native starch. This study showed an efficient method for preparing starch spherulites with uniform granule morphology and small particle size from normal corn starch. The ratios of α-amylase and amyloglucosidase in enzymatic hydrolysis had little effect on the structure of the starch spherulites.

4-Hydroxybenzoic acid from hydrothermal pretreatment of oil palm empty fruit bunches - Its origin and influence on biomass conversion

DEFF Research Database (Denmark)

Rasmussen, Helena; Mogensen, Kit H.; Jeppesen, Martin D.

2016-01-01

An unknown major compound, characteristically occurring during processing of oil palm empty fruit bunches was identified with LC-DAD-ESI-MS/MS to be 4-hydroxybenzoic acid. Lignin from oil palm empty fruit bunches contains 4-hydroxybenzoic acid so a tempting conclusion was that the 4-hydroxybenzoic...... biomass hydrothermal pretreatment conditions. 5-methylfuran-2-carbaldehyde only differs from furfural by having an extra methyl group and the degradation route indicates that it may be a new important degradation compound to consider in other biomass feedstocks rich in deoxysugars such as rhamnose...... or fucose, e.g. pectin rich biomasses. Assessment of the influence of 4-hydroxybenzoic acid in the enzymatic hydrolysis of pretreated oil palm empty fruit bunches as well as its presence during fermentation showed that 4-hydroxybenzoic acid is not inhibiting or mediating neither on the enzymatic hydrolysis...

PRETREATING THORIUM FOR ELECTROPLATING

Science.gov (United States)

Beach, J.G.; Schaer, G.R.

1959-07-28

A method is presented for pretreating a thorium surface prior to electroplating the surface. The pretreatment steps of the invention comprise cleaning by vapor blasting the surface, anodically pickling in a 5 to 15% by volume aqueous hydrochloric acid bath with a current of 125 to 250 amp/sq ft for 3 to 5 min at room temperature, chemically pickling the surface in a 5 to 15% by volume of aqueous sulfuric acid for 3 to 5 min at room temperature, and rinsing the surface with water.

Biomass Enzymatic Saccharification Is Determined by the Non-KOH-Extractable Wall Polymer Features That Predominately Affect Cellulose Crystallinity in Corn

Science.gov (United States)

Wu, Leiming; Wang, Hongwu; Wu, Zhiliang; Li, Ming; Huang, Pengyan; Feng, Shengqiu; Chen, Peng; Zheng, Yonglian; Peng, Liangcai

2014-01-01

Corn is a major food crop with enormous biomass residues for biofuel production. Due to cell wall recalcitrance, it becomes essential to identify the key factors of lignocellulose on biomass saccharification. In this study, we examined total 40 corn accessions that displayed a diverse cell wall composition. Correlation analysis showed that cellulose and lignin levels negatively affected biomass digestibility after NaOH pretreatments at pbiomass saccharification after pretreatments with NaOH and H2SO4 at three concentrations. Notably, despite that the non-KOH-extractable residues covered 12%–23% hemicelluloses and lignin of total biomass, their wall polymer features exhibited the predominant effects on biomass enzymatic hydrolysis including Ara substitution degree of xylan (reverse Xyl/Ara) and S/G ratio of lignin. Furthermore, the non-KOH-extractable polymer features could significantly affect lignocellulose crystallinity at pbiomass digestibility. Hence, this study could suggest an optimal approach for genetic modification of plant cell walls in bioenergy corn. PMID:25251456

Lignocellulose pretreatment technologies affect the level of enzymatic cellulose oxidation by LPMO

DEFF Research Database (Denmark)

Rodríguez-Zúñiga, Ursula Fabiola; Cannella, David; de Campos Giordano, Roberto

2015-01-01

of the cellulose oxidizing enzyme lytic polysaccharide monooxygenase (LPMO). The highest activity of LPMO was observed for the hydrothermally pretreated biomasses, which also contained the highest level of lignin. All hydrolysis were done at high dry matter levels, using a commercial enzyme preparation containing......Sugarcane bagasse, corn stover, and wheat straw are among the most available resources for production of cellulosic ethanol. For these biomasses we study the influence of pre-treatment methods on the chemical composition, as well as on the subsequent reactions of enzymatic hydrolysis and oxidation...

Structural characterization of alkaline hydrogen peroxide pretreated grasses exhibiting diverse lignin phenotypes

Science.gov (United States)

2012-01-01

Background For cellulosic biofuels processes, suitable characterization of the lignin remaining within the cell wall and correlation of quantified properties of lignin to cell wall polysaccharide enzymatic deconstruction is underrepresented in the literature. This is particularly true for grasses which represent a number of promising bioenergy feedstocks where quantification of grass lignins is particularly problematic due to the high fraction of p-hydroxycinnamates. The main focus of this work is to use grasses with a diverse range of lignin properties, and applying multiple lignin characterization platforms, attempt to correlate the differences in these lignin properties to the susceptibility to alkaline hydrogen peroxide (AHP) pretreatment and subsequent enzymatic deconstruction. Results We were able to determine that the enzymatic hydrolysis of cellulose to to glucose (i.e. digestibility) of four grasses with relatively diverse lignin phenotypes could be correlated to total lignin content and the content of p-hydroxycinnamates, while S/G ratios did not appear to contribute to the enzymatic digestibility or delignification. The lignins of the brown midrib corn stovers tested were significantly more condensed than a typical commercial corn stover and a significant finding was that pretreatment with alkaline hydrogen peroxide increases the fraction of lignins involved in condensed linkages from 88–95% to ~99% for all the corn stovers tested, which is much more than has been reported in the literature for other pretreatments. This indicates significant scission of β-O-4 bonds by pretreatment and/or induction of lignin condensation reactions. The S/G ratios in grasses determined by analytical pyrolysis are significantly lower than values obtained using either thioacidolysis or 2DHSQC NMR due to presumed interference by ferulates. Conclusions It was found that grass cell wall polysaccharide hydrolysis by cellulolytic enzymes for grasses exhibiting a diversity of

Structural characterization of alkaline hydrogen peroxide pretreated grasses exhibiting diverse lignin phenotypes

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Li Muyang

2012-06-01

Full Text Available Abstract Background For cellulosic biofuels processes, suitable characterization of the lignin remaining within the cell wall and correlation of quantified properties of lignin to cell wall polysaccharide enzymatic deconstruction is underrepresented in the literature. This is particularly true for grasses which represent a number of promising bioenergy feedstocks where quantification of grass lignins is particularly problematic due to the high fraction of p-hydroxycinnamates. The main focus of this work is to use grasses with a diverse range of lignin properties, and applying multiple lignin characterization platforms, attempt to correlate the differences in these lignin properties to the susceptibility to alkaline hydrogen peroxide (AHP pretreatment and subsequent enzymatic deconstruction. Results We were able to determine that the enzymatic hydrolysis of cellulose to to glucose (i.e. digestibility of four grasses with relatively diverse lignin phenotypes could be correlated to total lignin content and the content of p-hydroxycinnamates, while S/G ratios did not appear to contribute to the enzymatic digestibility or delignification. The lignins of the brown midrib corn stovers tested were significantly more condensed than a typical commercial corn stover and a significant finding was that pretreatment with alkaline hydrogen peroxide increases the fraction of lignins involved in condensed linkages from 88–95% to ~99% for all the corn stovers tested, which is much more than has been reported in the literature for other pretreatments. This indicates significant scission of β-O-4 bonds by pretreatment and/or induction of lignin condensation reactions. The S/G ratios in grasses determined by analytical pyrolysis are significantly lower than values obtained using either thioacidolysis or 2DHSQC NMR due to presumed interference by ferulates. Conclusions It was found that grass cell wall polysaccharide hydrolysis by cellulolytic enzymes for grasses

Biological abatement of cellulase inhibitors.

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Cao, Guangli; Ximenes, Eduardo; Nichols, Nancy N; Zhang, Leyu; Ladisch, Michael

2013-10-01

Removal of enzyme inhibitors released during lignocellulose pretreatment is essential for economically feasible biofuel production. We tested bio-abatement to mitigate enzyme inhibitor effects observed in corn stover liquors after pretreatment with either dilute acid or liquid hot water at 10% (w/v) solids. Bio-abatement of liquors was followed by enzymatic hydrolysis of cellulose. To distinguish between inhibitor effects on enzymes and recalcitrance of the substrate, pretreated corn stover solids were removed and replaced with 1% (w/v) Solka Floc. Cellulose conversion in the presence of bio-abated liquors from dilute acid pretreatment was 8.6% (0.1x enzyme) and 16% (1x enzyme) higher than control (non-abated) samples. In the presence of bio-abated liquor from liquid hot water pretreated corn stover, 10% (0.1x enzyme) and 13% (1x enzyme) higher cellulose conversion was obtained compared to control. Bio-abatement yielded improved enzyme hydrolysis in the same range as that obtained using a chemical (overliming) method for mitigating inhibitors. Copyright © 2013 Elsevier Ltd. All rights reserved.

Enhanced thermophilic fermentative hydrogen production from cassava stillage by chemical pretreatments.

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Wang, Wen; Luo, Gang; Xie, Li; Zhou, Qi

2013-01-01

Acid and alkaline pretreatments for enhanced hydrogen production from cassava stillage were investigated in the present study. The result showed that acid pretreatment was suitable for enhancement of soluble carbohydrate while alkaline pretreatment stimulated more soluble total organic carbon production from cassava stillage. Acid pretreatment thereby has higher capacity to promote hydrogen production compared with alkaline pretreatment. Effects of pretreatment temperature, time and acid concentration on hydrogen production were also revealed by response surface methodology. The results showed that the increase of all factors increased the soluble carbohydrate production, whereas hydrogen production was inhibited when the factors exceeded their optimal values. The optimal conditions for hydrogen production were pretreatment temperature 89.5 °C, concentration 1.4% and time 69 min for the highest hydrogen production of 434 mL, 67% higher than raw cassava stillage.

Plasma-Assisted Pretreatment of Wheat Straw for Ethanol Production

DEFF Research Database (Denmark)

Schultz-Jensen, Nadja; Kádár, Zsófia; Thomsen, Anne Belinda

2011-01-01

(0–7 h), e.g., oxalic acid and acetovanillon. Interestingly, washing had no effect on the ethanol production with pretreatment times up to 1 h. Washing improved the glucose availability with pretreatment times of more than 2 h. One hour of ozonisation was found to be optimal for the use of washed...... carboxylic acids and phenolic compounds were found, e.g., vanillic acid, acetic acid, and formic acid. Some components had the highest concentration at the beginning of the ozonisation process (0.5, 1 h), e.g., 4-hydroxybenzladehyde, while the concentration of others increased during the entire pretreatment...

Biomass Enzymatic Saccharification Is Determined by the Non-KOH-Extractable Wall Polymer Features That Predominately Affect Cellulose Crystallinity in Corn

OpenAIRE

Jia, Jun; Yu, Bin; Wu, Leiming; Wang, Hongwu; Wu, Zhiliang; Li, Ming; Huang, Pengyan; Feng, Shengqiu; Chen, Peng; Zheng, Yonglian; Peng, Liangcai

2014-01-01

Corn is a major food crop with enormous biomass residues for biofuel production. Due to cell wall recalcitrance, it becomes essential to identify the key factors of lignocellulose on biomass saccharification. In this study, we examined total 40 corn accessions that displayed a diverse cell wall composition. Correlation analysis showed that cellulose and lignin levels negatively affected biomass digestibility after NaOH pretreatments at p

Response surface optimization of the thermal acid pretreatment of sugar beet pulp for bioethanol production using Trichoderma viride and Saccharomyces cerevisiae.

Science.gov (United States)

El-Gendy, Nour Sh; Madian, Hekmat R; Nassar, Hussein N; Amr, Salem S Abu

2015-09-15

Worldwide nowadays, relying on the second generation bioethanol from the lignocellulosic feedstock is a mandatory aim. However, one of the major drawbacks for high ethanol yield is the physical and chemical pretreatment of this kind of feedstock. As the pretreatment is a crucial process operation that modifies the lignocellulosic structure and enhances its accessibility for the high cost hydrolytic enzymes in an attempt to maximize the yield of the fermentable sugars. The objective of this work was to optimize and integrate a physicochemical pretreatment of one of the major agricultural wastes in Egypt; the sugar beet pulp (SBP) and the enzymatic saccharification of the pretreated SBP using a whole fungal cells with a separate bioethanol fermentation batch processes to maximize the bioethanol yield. The response surface methodology was employed in this study to statistically evaluate and optimize the conditions for a thermal acid pretreatment of SBP. The significance and the interaction effects of the concentrations of HCl and SBP and the reaction temperature and time were studied using a three-level central composite design of experiments. A quadratic model equation was obtained to maximize the production of the total reducing sugars. The validity of the predicted model was confirmed. The thermally acid pretreated SBP was further subjected to a solid state fermentation batch process using Trichoderma viride F94. The thermal acid pretreatment and fungal hydrolyzes were integrated with two parallel batch fermentation processes of the produced hydrolyzates using Saccharomyces cerevisiae Y39, that yielded a total of ≈ 48 g/L bioethanol, at a conversion rate of ≈ 0.32 g bioethanol/ g SBP. Applying the proposed integrated process, approximately 97.5 gallon of ethanol would be produced from a ton (dry weight) of SBP.

Effects of total replacement of soybean meal and corn on ruminal fermentation, volatile fatty acids, protozoa concentration, and gas production

Directory of Open Access Journals (Sweden)

A. Bahri

2018-03-01

Full Text Available The main purpose of this study is to evaluate the effect of total replacement of soybean meal and corn with triticale and faba bean or field pea on rumen fermentation, protozoa counts, and gas production of lactating ewes. A total of 30 Sicilo-Sarde ewes were randomly allocated into three groups and were fed 1.8 kg drymatter of oat hay plus 500 g of one of three concentrates: the first concentrate (CS was mainly composed of soybean meal, corn, and barley; the second (TFB was formed by triticale and faba bean; and the third (TFP was composed of triticale and field pea. The type of concentrate did not affect ruminal pH or ammonia nitrogen concentration (P  >  0.05. The individual concentrations of volatile fatty acids showed a significant interaction between the type of concentrate and sampling time (P  <  0.05, except for Butyric and Isobutyric acids. Within a post-feeding time, the pattern of evolution of total volatile fatty, acetic, and propionic acids differed significantly at 2 h post feeding (P  <  0.05, while butyric and valeric acid changed at 0 and 4 h post feeding. The type of concentrate affected the total number of ciliate protozoa and the Isotricha species (P  <  0.05, whereas Entodinium, Ophryoscolex, and Polyplastron were similar among concentrates (P  >  0.05. The cumulative gas production from the in vitro fermentation, the time of incubation, and their interaction was affected by concentrate (P  <  0.001. The substitution of soybean meal and corn in the concentrate with faba bean or field peas and triticale might maintain rumen parameters of dairy ewes.

Characteristics of Lignin Fractions from Dilute Acid Pretreated Switchgrass and Their Effect on Cellobiohydrolase from Trichoderma longibrachiatum

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Lan Yao

2018-02-01

Full Text Available To investigate the interactions between acid pretreated switchgrass lignin and cellobiohydrolase (CBH, three different lignin fractions were isolated from dilute acid pretreated switchgrass by (i ethanol extraction, followed by (ii dioxane/H2O extraction, and (iii cellulase treatment, respectively. Structural properties of each lignin fraction were elucidated by GPC, 13C-NMR, and 2D-HSQC NMR analyses. The adsorptions of CBH to the isolated lignin fractions were also studied by Langmuir adsorption isotherms. Ethanol-extractable lignin fraction, mainly composed of syringyl (S and guaiacyl (G units, had the lowest molecular weight, while dioxane/H2O-extracted lignin fraction had the lowest S/G ratio with higher content of p-coumaric acid (pCA unit. The residual lignin fraction after enzymatic treatment had the highest S/G ratio without hydroxyphenyl (H unit. Strong associations were found between lignin properties such as lignin composition and S/G ratio and its non-productive enzyme adsorption factors including the maximum adsorption capacity and binding strength.

Chemical and physicochemical pretreatment of lignocellulosic biomass: a review.

Science.gov (United States)

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

2011-01-01

Overcoming the recalcitrance (resistance of plant cell walls to deconstruction) of lignocellulosic biomass is a key step in the production of fuels and chemicals. The recalcitrance is due to the highly crystalline structure of cellulose which is embedded in a matrix of polymers-lignin and hemicellulose. The main goal of pretreatment is to overcome this recalcitrance, to separate the cellulose from the matrix polymers, and to make it more accessible for enzymatic hydrolysis. Reports have shown that pretreatment can improve sugar yields to higher than 90% theoretical yield for biomass such as wood, grasses, and corn. This paper reviews different leading pretreatment technologies along with their latest developments and highlights their advantages and disadvantages with respect to subsequent hydrolysis and fermentation. The effects of different technologies on the components of biomass (cellulose, hemicellulose, and lignin) are also reviewed with a focus on how the treatment greatly enhances enzymatic cellulose digestibility.

Effects of Feeding Corn-lablab Bean Mixture Silages on Nutrient Apparent Digestibility and Performance of Dairy Cows

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Yongli Qu

2013-04-01

Full Text Available This study estimated the fermentation characteristics and nutrient value of corn-lablab bean mixture silages relative to corn silages. The effects of feeding corn-lablab bean mixture silages on nutrient apparent digestibility and milk production of dairy cows in northern China were also investigated. Three ruminally cannulated Holstein cows were used to determine the ruminal digestion kinetics and ruminal nutrient degradability of corn silage and corn-lablab bean mixture silages. Sixty lactating Holstein cows were randomly divided into two groups of 30 cows each. Two diets were formulated with a 59:41 forage: concentrate ratio. Corn silage and corn-lablab bean mixture silages constituted 39.3% of the forage in each diet, with Chinese wildrye hay constituting the remaining 60.7%. Corn-lablab bean mixture silages had higher lactic acid, acetic acid, dry matter (DM, crude protein (CP, ash, Ca, ether extract concentrations and ruminal nutrient degradability than monoculture corn silage (p<0.05. Neutral detergent fiber (NDF and acid detergent fiber (ADF concentrations of corn-lablab bean mixture silages were lower than those of corn silage (p<0.05. The digestibility of DM, CP, NDF, and ADF for cows fed corn-lablab bean mixture silages was higher than for those fed corn silage (p<0.05. Feeding corn-lablab bean mixture silages increased milk yield and milk protein of dairy cows when compared with feeding corn silage (p<0.05. The economic benefit for cow fed corn-lablab bean mixture silages was 8.43 yuan/day/cow higher than that for that fed corn silage. In conclusion, corn-lablab bean mixture improved the fermentation characteristics and nutrient value of silage compared with monoculture corn. In this study, feeding corn-lablab bean mixture silages increased milk yield, milk protein and nutrient apparent digestibility of dairy cows compared with corn silage in northern China.

Compositional analysis of genetically modified corn events (NK603, MON88017×MON810 and MON89034×MON88017) compared to conventional corn.

Science.gov (United States)

Rayan, Ahmed M; Abbott, Louise C

2015-06-01

Compositional analysis of genetically modified (GM) crops continues to be an important part of the overall evaluation in the safety assessment for these materials. The present study was designed to detect the genetic modifications and investigate the compositional analysis of GM corn containing traits of multiple genes (NK603, MON88017×MON810 and MON89034×MON88017) compared with non-GM corn. Values for most biochemical components assessed for the GM corn samples were similar to those of the non-GM control or were within the literature range. Significant increases were observed in protein, fat, fiber and fatty acids of the GM corn samples. The observed increases may be due to the synergistic effect of new traits introduced into corn varieties. Furthermore, SDS-PAGE analysis showed high similarity among the protein fractions of the investigated corn samples. These data indicate that GM corn samples were compositionally equivalent to, and as nutritious as, non-GM corn. Copyright © 2014 Elsevier Ltd. All rights reserved.

Influence of different SSF conditions on ethanol production from corn stover at high solids loadings

DEFF Research Database (Denmark)

Gladis, Arne; Bondesson, Pia-Maria; Galbe, Mats

2015-01-01

In this study, three different kinds of simultaneous saccharification and fermentation (SSF) of washed pretreated corn stover with water-insoluble solids (WIS) content of 20% were investigated to find which one resulted in highest ethanol yield at high-solids loadings. The different methods were...

DEVELOPMENT OF ADHESIVE TO THE BASIS OF CORN AND CASSAVA STARCH

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Rosane Furtado Fabrício

2014-05-01

Full Text Available Corn and native cassava starch were modified by oxidation and acid hydrolysis, aiming to develop paper and paperboard stickers. The oxidation was made with Sodium hypochlorite (NaOCl in two distinct concentrations of active chloride which is present on oxidizing agent solution. The synthesis resulting products were used to make stickers and they were compared to corn and cassava starch based stickers without any modification, as well as commercial stickers based on polyvinyl acetate (PVA. Two different methodologies were tested using acid hydrolysis to modify corn and cassava starch, both using phosphoric acid (H3PO4 in order to obtain dextrin and subsequently use it in the production of stickers and also comparing them to petrochemical-based commercial stickers. Considering the different starch modifications methods (oxidation and acid hydrolysis, stickers based on renewable raw material were obtained, which combine biodegradability, low costs and availability.

Enhanced enzymatic hydrolysis and acetone-butanol-ethanol fermentation of sugarcane bagasse by combined diluted acid with oxidate ammonolysis pretreatment.

Science.gov (United States)

Li, Hailong; Xiong, Lian; Chen, Xuefang; Wang, Can; Qi, Gaoxiang; Huang, Chao; Luo, Mutan; Chen, Xinde

2017-03-01

This study aims to propose a biorefinery pretreatment technology for the bioconversion of sugarcane bagasse (SB) into biofuels and N-fertilizers. Performance of diluted acid (DA), aqueous ammonia (AA), oxidate ammonolysis (OA) and the combined DA with AA or OA were compared in SB pretreatment by enzymatic hydrolysis, structural characterization and acetone-butanol-ethanol (ABE) fermentation. Results indicated that DA-OA pretreatment improves the digestibility of SB by sufficiently hydrolyzing hemicellulose into fermentable monosaccharides and oxidating lignin into soluble N-fertilizer with high nitrogen content (11.25%) and low C/N ratio (3.39). The enzymatic hydrolysates from DA-OA pretreated SB mainly composed of glucose was more suitable for the production of ABE solvents than the enzymatic hydrolysates from OA pretreated SB containing high ratio of xylose. The fermentation of enzymatic hydrolysates from DA-OA pretreated SB produced 12.12g/L ABE in 120h. These results suggested that SB could be utilized efficient, economic, and environmental by DA-OA pretreatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of Dilute Acid and Ionic Liquid Pretreatment of Switchgrass: Biomass Recalcitrance, Delignification and Enzymatic Saccharification

Science.gov (United States)

The efficiency of two biomass pretreatment technologies, dilute acid hydrolysis and dissolution in an ionic liquid, are compared in terms of delignification, saccharification efficiency and saccharide yields with switchgrass serving as a model bioenergy crop. When subject to ionic liquid pretreatme...

Methods of pretreating comminuted cellulosic material with carbonate-containing solutions

Energy Technology Data Exchange (ETDEWEB)

Francis, Raymond

2012-11-06

Methods of pretreating comminuted cellulosic material with an acidic solution and then a carbonate-containing solution to produce a pretreated cellulosic material are provided. The pretreated material may then be further treated in a pulping process, for example, a soda-anthraquinone pulping process, to produce a cellulose pulp. The pretreatment solutions may be extracted from the pretreated cellulose material and selectively re-used, for example, with acid or alkali addition, for the pretreatment solutions. The resulting cellulose pulp is characterized by having reduced lignin content and increased yield compared to prior art treatment processes.

Rich biotin content in lignocellulose biomass plays the key role in determining cellulosic glutamic acid accumulation by Corynebacterium glutamicum.

Science.gov (United States)