Effect of additives on adsorption and desorption behavior of xylanase on acid-insoluble lignin from corn stover and wheat straw.

PubMed

Li, Yanfei; Ge, Xiaoyan; Sun, Zongping; Zhang, Junhua

2015-06-01

The competitive adsorption between cellulases and additives on lignin in the hydrolysis of lignocelluloses has been confirmed, whereas the effect of additives on the interaction between xylanase and lignin is not clear. In this work, the effects of additives, poly(ethylene glycol) 2000, poly(ethylene glycol) 6000, Tween 20, and Tween 80, on the xylanase adsorption/desorption onto/from acid-insoluble lignin from corn stover (CS-lignin) and wheat straw (WS-lignin) were investigated. The results indicated that the additives could adsorb onto isolated lignin and reduce the xylanase adsorption onto lignin. Compared to CS-lignin, more additives could adsorb onto WS-lignin, making less xylanase adsorbed onto WS-lignin. In addition, the additives could enhance desorption of xylanase from lignin, which might be due to the competitive adsorption between xylanase and additives on lignin. The released xylanase from lignin still exhibited hydrolytic capacity in the hydrolysis of isolated xylan and xylan in corn stover. Copyright © 2015 Elsevier Ltd. All rights reserved.

Bioprocessing of wheat straw into nutritionally rich and digested cattle feed

PubMed Central

Shrivastava, Bhuvnesh; Jain, Kavish Kumar; Kalra, Anup; Kuhad, Ramesh Chander

2014-01-01

Wheat straw was fermented by Crinipellis sp. RCK-1, a lignin degrading fungus, under solid state fermentation conditions. The fungus degraded 18.38% lignin at the expense of 10.37% cellulose within 9 days. However, when wheat straw fermented for different duration was evaluated in vitro, the 5 day fungal fermented wheat straw called here “Biotech Feed” was found to possess 36.74% organic matter digestibility (OMD) and 5.38 (MJ/Kg Dry matter) metabolizable energy (ME). The Biotech Feed was also observed to be significantly enriched with essential amino acids and fungal protein by fungal fermentation, eventually increasing its nutritional value. The Biotech Feed upon in vitro analysis showed potential to replace 50% grain from concentrate mixture. Further, the calves fed on Biotech Feed based diets exhibited significantly higher (p<0.05) dry matter intake (DMI: 3.74 Kg/d), dry matter digestibility (DMD: 57.82%), total digestible nutrients (TDN: 54.76%) and comparatively gained 50 g more daily body weight. PMID:25269679

Fate of Carbohydrates and Lignin during Composting and Mycelium Growth of Agaricus bisporus on Wheat Straw Based Compost

PubMed Central

Jurak, Edita; Punt, Arjen M.; Arts, Wim; Kabel, Mirjam A.; Gruppen, Harry

2015-01-01

In wheat straw based composting, enabling growth of Agaricus bisporus mushrooms, it is unknown to which extent the carbohydrate-lignin matrix changes and how much is metabolized. In this paper we report yields and remaining structures of the major components. During the Phase II of composting 50% of both xylan and cellulose were metabolized by microbial activity, while lignin structures were unaltered. During A. bisporus’ mycelium growth (Phase III) carbohydrates were only slightly consumed and xylan was found to be partially degraded. At the same time, lignin was metabolized for 45% based on pyrolysis GC/MS. Remaining lignin was found to be modified by an increase in the ratio of syringyl (S) to guaiacyl (G) units from 0.5 to 0.7 during mycelium growth, while fewer decorations on the phenolic skeleton of both S and G units remained. PMID:26436656

Microbial production of biopolymers from the renewable resource wheat straw.

PubMed

Gasser, E; Ballmann, P; Dröge, S; Bohn, J; König, H

2014-10-01

Production of poly-ß-hydroxybutyrate (PHB) and the chemical basic compound lactate from the agricultural crop 'wheat straw' as a renewable carbon resource. A thermal pressure hydrolysis procedure for the breakdown of wheat straw was applied. By this means, the wheat straw was converted into a partially solubilized hemicellulosic fraction, consisting of sugar monomers, and an insoluble cellulosic fraction, containing cellulose, lignin and a small portion of hemicellulose. The insoluble cellulosic fraction was further hydrolysed by commercial enzymes in monomers. The production of PHB from the sugar monomers originating from hemicellulose or cellulose was achieved by the isolates Bacillus licheniformis IMW KHC 3 and Bacillus megaterium IMW KNaC 2. The basic chemical compound, lactate, a starting compound for the production of polylactide (PLA), was formed by some heterofermentative lactic acid bacteria (LAB) able to grow with xylose from the hemicellulosic wheat straw hydrolysate. Two strains were selected which were able to produce PHB from the sugars both from the hemicellulosic and the cellulosic fraction of the wheat straw. In addition, some of the LAB tested were capable of producing lactate from the hemicellulosic hydrolysate. The renewable resource wheat straw could serve as a substrate for microbiologically produced basic chemicals and biodegradable plastics. © 2014 The Society for Applied Microbiology.

Nutraceutical and functional scenario of wheat straw.

PubMed

Pasha, Imran; Saeed, Farhan; Waqas, Khalid; Anjum, Faqir Muhammad; Arshad, Muhammad Umair

2013-01-01

In the era of nutrition, much focus has been remunerated to functional and nutraceutical foodstuffs. The health endorsing potential of such provisions is attributed to affluent phytochemistry. These dynamic constituents have functional possessions that are imperative for cereal industry. The functional and nutraceutical significance of variety of foods is often accredited to their bioactive molecules. Numerous components have been considered but wheat straw and its diverse components are of prime consideration. In this comprehensive dissertation, efforts are directed to elaborate the functional and nutraceutical importance of wheat straw. Wheat straw is lignocellulosic materials including cellulose, hemicellulose and lignin. It hold various bioactive compounds such as policosanols, phytosterols, phenolics, and triterpenoids, having enormous nutraceutical properties like anti-allergenic, anti-artherogenic, anti-inflammatory, anti-microbial, antioxidant, anti-thrombotic, cardioprotective and vasodilatory effects, antiviral, and anticancer. These compounds are protecting against various ailments like hypercholesterolemia, intermittent claudication, benign prostatic hyperplasia and cardiovascular diseases. Additionally, wheat straw has demonstrated successfully, low cost, renewable, versatile, widely distributed, easily available source for the production of biogas, bioethanol, and biohydrogen in biorefineries to enhance the overall effectiveness of biomass consumption in protected and eco-friendly environment. Furthermore, its role in enhancing the quality and extending the shelf life of bakery products through reducing the progression of staling and retrogradation is limelight of the article.

Biogeochemical Processes That Produce Dissolved Organic Matter From Wheat Straw

USGS Publications Warehouse

Wershaw, Robert L.; Rutherford, David W.; Leenheer, Jerry A.; Kennedy, Kay R.; Cox, Larry G.; Koci, Donald R.

2003-01-01

The chemical reactions that lead to the formation of dissolved organic matter (DOM) in natural waters are poorly understood. Studies on the formation of DOM generally are complicated because almost all DOM isolates have been derived from mixtures of plant species composed of a wide variety of different types of precursor compounds for DOM formation. This report describes a study of DOM derived mainly from bales of wheat straw that had been left in a field for several years. During this period of time, black water from the decomposing wheat straw accumulated in pools in the field. The nuclear magnetic resonance and infrared spectra of the black water DOM indicate that it is composed almost entirely of lignin and carbohydrate polymeric units. Analysis by high-performance size-exclusion chromatography with multi-angle laser-light scattering detection indicates that the number average molecular weight of the DOM is 124,000 daltons. The results presented in this report indicate that the black water DOM is composed of hemicellulose chains cross-linked to lignin oligomers. These types of structures have been shown to exist in the hemicellulose matrix of plant cell walls. The cross-linked lignin-hemicellulose complexes apparently were released from partially degraded wheat-straw cell walls with little alteration. In solution in the black water, these lignin-hemicellulose polymers fold into compact globular particles in which the nonpolar parts of the polymer form the interiors of the particles and the polar groups are on the exterior surfaces of the particles. The tightly folded, compact conformation of these particles probably renders them relatively resistant to microbial degradation. This should be especially the case for the aromatic lignin structures that will be buried in the interiors of the particles.

Effect of ozonolysis pretreatment on enzymatic digestibility of wheat and rye straw.

PubMed

García-Cubero, M A Teresa; González-Benito, Gerardo; Indacoechea, Irune; Coca, Mónica; Bolado, Silvia

2009-02-01

Wheat and rye straws were pretreated with ozone to increase the enzymatic hydrolysis extent of potentially fermentable sugars. Through a 2(5-1) factorial design, this work studies the influence of five operating parameters (moisture content, particle size, ozone concentration, type of biomass and air/ozone flow rate) on ozonization pretreatment of straw in a fixed bed reactor under room conditions. The acid insoluble lignin content of the biomass was reduced in all experiments involving hemicellulose degradation. Near negligible losses of cellulose were observed. Enzymatic hydrolysis yields of up to 88.6% and 57% were obtained compared to 29% and 16% in non-ozonated wheat and rye straw respectively. Moisture content and type of biomass showed the most significant effects on ozonolysis. Additionally, ozonolysis experiments in basic medium with sodium hydroxide evidenced a reduction in solubilization and/or degradation of lignin and reliable cellulose and hemicellulose degradation.

Pretreatment and fractionation of wheat straw for production of fuel ethanol and value-added co-products in a biorefinery

USDA-ARS?s Scientific Manuscript database

An integrated process has been developed for a wheat straw biorefinery. In this process wheat straw was pretreated by soaking in aqueous ammonia (SAA), which extensively removed lignin but preserved high percentages of the carbohydrate fractions for subsequent bioconversion. The pretreatment condi...

Improving the enzymatic hydrolysis of dilute acid pretreated wheat straw by metal ion blocking of non-productive cellulase adsorption on lignin.

PubMed

Akimkulova, Ardak; Zhou, Yan; Zhao, Xuebing; Liu, Dehua

2016-05-01

Eleven salts were selected to screen the possible metal ions for blocking the non-productive adsorption of cellulase onto the lignin of dilute acid pretreated wheat straw. Mg(2+) was screened finally as the promising candidate. The optimal concentration of MgCl2 was 1 mM, but the beneficial action was also dependent on pH, hydrolysis time and cellulase loading. Significant improvement of glucan conversion (19.3%) was observed at low cellulase loading (5 FPU/g solid). Addition of isolated lignins, tannic acid and lignin model compounds to pure cellulose hydrolysis demonstrated that phenolic hydroxyl group (Ph-OH) was the main active site blocked by Mg(2+). The interaction between Mg(2+) and Ph-OH of lignin monomeric moieties followed an order of p-hydroxyphenyl (H)>guaiacyl (G)>syringyl (S). Mg(2+) blocking made the lignin surface less negatively charged, which might weaken the hydrogen bonding and electrostatically attractive interaction between lignin and cellulase enzymes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Removal of straw lignin from spent pulping liquor using synthetic cationic and biobased flocculants

USDA-ARS?s Scientific Manuscript database

Aqueous alkaline delignification of wheat straw produces hemicellulose for bioenergy and other applications. After removal of the hemicellulose, spent pulping liquor (SPL) remains. The spent pulping liquor is approximately 28% water, 40% ash, 3% hemicellulose, 25% lignin, 5% protein, and less than...

Ozone pretreatment and fermentative hydrolysis of wheat straw

NASA Astrophysics Data System (ADS)

Ben'ko, E. M.; Chukhchin, D. G.; Lunin, V. V.

2017-11-01

Principles of the ozone pretreatment of wheat straw for subsequent fermentation into sugars are investigated. The optimum moisture contents of straw in the ozonation process are obtained from data on the kinetics of ozone absorbed by samples with different contents of water. The dependence of the yield of reducing sugars in the fermentative reaction on the quantity of absorbed ozone is established. The maximum conversion of polysaccharides is obtained at ozone doses of around 3 mmol/g of biomass, and it exceeds the value for nonozonated samples by an order of magnitude. The yield of sugar falls upon increasing the dose of ozone. The process of removing lignin from the cell walls of straw during ozonation is visualized by means of scanning electron microscopy.

Cell-wall structural changes in wheat straw pretreated for bioethanol production

PubMed Central

Kristensen, Jan B; Thygesen, Lisbeth G; Felby, Claus; Jørgensen, Henning; Elder, Thomas

2008-01-01

Background Pretreatment is an essential step in the enzymatic hydrolysis of biomass and subsequent production of bioethanol. Recent results indicate that only a mild pretreatment is necessary in an industrial, economically feasible system. The Integrated Biomass Utilisation System hydrothermal pretreatment process has previously been shown to be effective in preparing wheat straw for these processes without the application of additional chemicals. In the current work, the effect of the pretreatment on the straw cell-wall matrix and its components are characterised microscopically (atomic force microscopy and scanning electron microscopy) and spectroscopically (attenuated total reflectance Fourier transform infrared spectroscopy) in order to understand this increase in digestibility. Results The hydrothermal pretreatment does not degrade the fibrillar structure of cellulose but causes profound lignin re-localisation. Results from the current work indicate that wax has been removed and hemicellulose has been partially removed. Similar changes were found in wheat straw pretreated by steam explosion. Conclusion Results indicate that hydrothermal pretreatment increases the digestibility by increasing the accessibility of the cellulose through a re-localisation of lignin and a partial removal of hemicellulose, rather than by disruption of the cell wall. PMID:18471316

Reinforcement of the bio-gas conversion from pyrolysis of wheat straw by hot caustic pre-extraction.

PubMed

Zhang, Lilong; Chen, Keli; He, Liang; Peng, Lincai

2018-01-01

Pyrolysis has attracted growing interest as a versatile means to convert biomass into valuable products. Wheat straw has been considered to be a promising biomass resource due to its low price and easy availability. However, most of the products obtained from wheat straw pyrolysis are usually of low quality. Hot soda extraction has the advantage of selective dissolution of lignin whilst retaining the carbohydrates. This can selectively convert biomass into high-quality desired products and suppress the formation of undesirable products. The aim of this study was to investigate the pyrolysis properties of wheat straw under different hot caustic pretreatment conditions. Compared with the untreated straw, a greater amount of gas was released and fewer residues were retained in the extracted wheat straw, which was caused by an increase in porosity. When the NaOH loading was 14%, the average pore size of the extracted straw increased by 12% and the cumulative pore volume increased by 157% compared with the untreated straw. The extracted straw obtained from the 14% NaOH extraction was clearly selective for pyrolysis products. On one hand, many lignin pyrolysis products disappeared, and only four main lignin-unit-pyrolysis products were retained. On the other hand, polysaccharide pyrolysis products were enriched. Both propanone and furfural have outstanding peak intensities that could account for approximately 30% of the total pyrolysis products. However, with the excessive addition of NaOH (i.e. > 22% w/w) during pretreatment, the conversion of bio-gas products decreased. Thermogravimetric and low-temperature nitrogen-adsorption analysis showed that the pore structure had been seriously destroyed, leading to the closing of the release paths of the bio-gas and thus increasing the re-polymerisation of small bio-gas molecules. After suitable extraction (14% NaOH loading extraction), a considerable amount (25%) of the soluble components dissolved out of the straw. This

Simulation of the ozone pretreatment of wheat straw.

PubMed

Bhattarai, Sujala; Bottenus, Danny; Ivory, Cornelius F; Gao, Allan Haiming; Bule, Mahesh; Garcia-Perez, Manuel; Chen, Shulin

2015-11-01

Wheat straw is a potential feedstock in biorefinery for sugar production. However, the cellulose, which is the major source of sugar, is protected by lignin. Ozonolysis deconstructs the lignin and makes cellulose accessible to enzymatic digestion. In this study, the change in lignin concentration with different ozonolysis times (0, 1, 2, 3, 5, 7, 10, 15, 20, 30, 60min) was fit to two different kinetic models: one using the model developed by Garcia-Cubero et al. (2012) and another including an outer mass transfer barrier or "cuticle" region where ozone mass transport is reduced in proportion to the mass of unreacted insoluble lignin in the cuticle. The kinetic parameters of two mathematical models for predicting the soluble and insoluble lignin at different pretreatment time were determined. The results showed that parameters derived from the cuticle-based model provided a better fit to experimental results compared to a model without a cuticle layer. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lignocellulose degradation patterns, structural changes, and enzyme secretion by Inonotus obliquus on straw biomass under submerged fermentation.

PubMed

Xu, Xiangqun; Xu, Zhiqi; Shi, Song; Lin, Mengmeng

2017-10-01

This study examined the white rot fungus I. obliquus on the degradation of three types of straw biomass and the production of extracellular lignocellulolytic enzymes under submerged fermentation. The fungus process resulted in a highest lignin loss of 72%, 39%, and 47% in wheat straw, rice straw, and corn stover within 12days, respectively. In merely two days, the fungus selectively degraded wheat straw lignin by 37%, with only limited cellulose degradation (13%). Fourier transform infrared spectroscopy revealed that the fungus most effectively degraded the wheat straw lignin and rice straw crystalline cellulose. Scanning electronic microscopy showed the most pronounced structural changes in wheat straw. High activities of manganese peroxidase (159.0U/mL) and lignin peroxidase (123.4U/mL) were observed in wheat straw culture on Day 2 and 4, respectively. Rice straw was the best substrate to induce the production of cellulase and xylanase. Copyright © 2017 Elsevier Ltd. All rights reserved.

Organosolv pretreatment by crude glycerol from oleochemicals industry for enzymatic hydrolysis of wheat straw.

PubMed

Sun, Fubao; Chen, Hongzhang

2008-09-01

In order to defray the cost of biodiesel production, the ensuing work was to further investigate utilization of the crude glycerol (CG) from oleochemicals industry in the atmospheric autocatalytic organosolv pretreatment (AAOP) to enhance enzymatic hydrolysis. The AAOP-CG enabled wheat straw to achieve with reasonable enzymatic hydrolysis yields, reaching 75% for the wet substrate and 63% for the dried. Lipophilic compounds from the CG formed pitch deposition on the fiber, which was responsible for low delignification (30%) and also troublesome in practical operation. Pitch deposits itself had no significant role on enzymatic hydrolysis. A striking finding of the lignin recondensation and/or lignin-carbohydrate complex helped explain why dried pretreated wheat straw had a low enzymatic hydrolysis yield. The CG was suitable for the AAOP to enhance enzymatic hydrolysis of lignocellulosic biomass. But it was advisable to remove lipophilic compounds from crude glycerol before utilization.

Oxidative polymerization of lignins by laccase in water-acetone mixture.

PubMed

Fiţigău, Ionița Firuța; Peter, Francisc; Boeriu, Carmen Gabriela

2013-01-01

The enzymatic oxidative polymerization of five technical lignins with different molecular properties, i.e. Soda Grass/Wheat straw Lignin, Organosolv Hardwood Lignin, Soda Wheat straw Lignin, Alkali pretreated Wheat straw Lignin, and Kraft Softwood was studied. All lignins were previously fractionated by acetone/water 50:50 (v/v) and the laccase-catalyzed polymerization of the low molecular weight fractions (Mw < 4000 g/mol) was carried out in the same solvent system. Reactivity of lignin substrates in laccase-catalyzed reactions was determined by monitoring the oxygen consumption. The oxidation reactions in 50% acetone in water mixture proceed with high rate for all tested lignins. Polymerization products were analyzed by size exclusion chromatography, FT-IR, and (31)P-NMR and evidence of important lignin modifications after incubation with laccase. Lignin polymers with higher molecular weight (Mw up to 17500 g/mol) were obtained. The obtained polymers have potential for applications in bioplastics, adhesives and as polymeric dispersants.

Decomposition Dynamics and Changes in Chemical Composition of Wheat Straw Residue under Anaerobic and Aerobic Conditions

PubMed Central

Gao, Hongjian; Chen, Xi; Wei, Junling; Zhang, Yajie; Zhang, Ligan; Chang, Jiang; Thompson, Michael L.

2016-01-01

Soil aeration is a crucial factor that regulates crop residue decomposition, and the chemical composition of decomposing crop residues may change the forms and availability of soil nutrients, such as N and P. However, to date, differences in the chemical composition of crop straw residues after incorporation into soil and during its decomposition under anaerobic vs. aerobic conditions have not been well documented. The objective of the present study was to assess changes in the C-containing functional groups of wheat straw residue during its decomposition in anaerobic and aerobic environments. A 12-month incubation experiment was carried out to investigate the temporal variations of mass, carbon, and nitrogen loss, as well as changes in the chemical composition of wheat (Triticum aestivum L) straw residues under anaerobic and aerobic conditions by measuring C-containing functional groups using solid state nuclear magnetic resonance (NMR) spectroscopy. The residual mass, carbon content, and nitrogen content of the straw residue sharply declined during the initial 3 months, and then slowly decreased during the last incubation period from 3 to 12 months. The decomposition rate constant (k) for mass loss under aerobic conditions (0.022 d-1) was higher than that under anaerobic conditions (0.014 d-1). The residual mass percentage of cellulose and hemicellulose in the wheat straw gradually declined, whereas that of lignin gradually increased during the entire 12-month incubation period. The NMR spectra of C-containing functional groups in the decomposing straw under both aerobic and anaerobic conditions were similar at the beginning of the incubation as well as at 1 month, 6 months, and 12 months. The main alterations in C-containing functional groups during the decomposition of wheat straw were a decrease in the relative abundances of O-alkyl C and an increase in the relative abundances of alkyl C, aromatic C and COO/N-C = O functional groups. The NMR signals of alkyl C

Alkaline-assisted screw press pretreatment affecting enzymatic hydrolysis of wheat straw.

PubMed

Yan, Qingqi; Wang, Yumei; Rodiahwati, Wawat; Spiess, Antje; Modigell, Michael

2017-02-01

Screw press processing of biomass can be considered as a suitable mechanically based pretreatment for biofuel production since it disrupts the structure of lignocellulosic biomass with high shear and pressure forces. The combination with chemical treatment has been suggested to increase the conversion of lignocellulosic biomass to fermentable sugars. Within the study, the synergetic effect of alkaline (sodium hydroxide, NaOH) soaking and screw press pretreatment on wheat straw was evaluated based on, e.g., sugar recovery and energy efficiency. After alkaline soaking (at 0.1 M for 30 min) and sequential screw press pretreatment with various screw press configurations and modified screw barrel, the lignin content of pretreated wheat straw was quantified. In addition, the structure of pretreated wheat straw was investigated by scanning electron microscopy and measurement of specific surface area. It could be shown that removal of lignin is more important than increase of surface area of the biomass to reach a high sugar recovery. The rate constant of the enzymatic hydrolysis increased from 1.1 × 10 -3  1/h for the non-treated material over 2.3 × 10 -3  1/h for the alkaline-soaked material to 26.9 × 10 -3  1/h for alkaline-assisted screw press pretreated material, indicating a nearly 25-fold improvement of the digestibility by the combined chemo-mechanical pretreatment. Finally, the screw configuration was found to be an important factor for improving the sugar recovery and for reducing the specific energy consumption of the screw press pretreatment.

Multilevel composition fractionation process for high-value utilization of wheat straw cellulose.

PubMed

Chen, Hong-Zhang; Liu, Zhi-Hua

2014-01-01

Biomass refining into multiple products has gained considerable momentum due to its potential benefits for economic and environmental sustainability. However, the recalcitrance of biomass is a major challenge in bio-based product production. Multilevel composition fractionation processes should be beneficial in overcoming biomass recalcitrance and achieving effective conversion of multiple compositions of biomass. The present study concerns the fractionation of wheat straw using steam explosion, coupled with ethanol extraction, and that this facilitates the establishment of sugars and lignin platform and enables the production of regenerated cellulose films. The results showed that the hemicellulose fractionation yield was 73% under steam explosion at 1.6 MPa for 5.2 minutes, while the lignin fractionation yield was 90% by ethanol extraction at 160°C for 2 hours and with 60% ethanol (v/v). The cellulose yield reached up to 93% after steam explosion coupled with ethanol extraction. Therefore, cellulose sugar, hemicellulose sugar, and lignin platform were established effectively in the present study. Long fibers (retained by a 40-mesh screening) accounted for 90% of the total cellulose fibers, and the glucan conversion of short fibers was 90% at 9.0 hours with a cellulase loading of 25 filter paper units/g cellulose in enzymatic hydrolysis. Regenerated cellulose film was prepared from long fibers using [bmim]Cl, and the tensile strength and breaking elongation was 120 MPa and 4.8%, respectively. The cross-section of regenerated cellulose film prepared by [bmim]Cl displayed homogeneous structure, which indicated a dense architecture and a better mechanical performance. Multilevel composition fractionation process using steam explosion followed by ethanol extraction was shown to be an effective process by which wheat straw could be fractionated into different polymeric fractions with high yields. High-value utilization of wheat straw cellulose was achieved by

Unraveling the effects of laccase treatment on enzymatic hydrolysis of steam-exploded wheat straw.

PubMed

Oliva-Taravilla, Alfredo; Moreno, Antonio D; Demuez, Marie; Ibarra, David; Tomás-Pejó, Elia; González-Fernández, Cristina; Ballesteros, Mercedes

2015-01-01

Laccase enzymes are promising detoxifying agents during lignocellulosic bioethanol production from wheat straw. However, they affect the enzymatic hydrolysis of this material by lowering the glucose recovery yields. This work aimed at explaining the negative effects of laccase on enzymatic hydrolysis. Relative glucose recovery in presence of laccase (10IU/g substrate) with model cellulosic substrate (Sigmacell) at 10% (w/v) was almost 10% points lower (P<0.01) than in the absence of laccase. This fact could be due to an increase in the competition of cellulose binding sites between the enzymes and a slight inhibition of β-glucosidase activity. However, enzymatic hydrolysis and infrared spectra of laccase-treated and untreated wheat straw filtered pretreated residue (WS-FPR), revealed that a grafting process of phenoxy radicals onto the lignin fiber could be the cause of diminished accessibility of cellulases to cellulose in pretreated wheat straw. Copyright © 2014 Elsevier Ltd. All rights reserved.

The degradation of wheat straw lignin

NASA Astrophysics Data System (ADS)

Liang, Jiaqi

2017-03-01

Lignin is a kind of formed by polymerization of aromatic alcohol, prices are lower and sources of renewable resources. Using lignin as raw material, through the push to resolve together preparation phenolic high value-added fine chemicals alkanes and aromatic hydrocarbons, such as the high grade biofuels, can partly replace fossil fuels as raw material to the production process, biomass resources is an important part of the comprehensive utilization of effective components. In lignin push solve clustering method, catalytic hydrogenolysis can directly to the lignin into liquid fuels, low oxygen content in the use of biofuels shows great potential. In this paper, through the optimization of the reaction time, reaction temperature, catalyst type and solvent type, dosage of catalyst, etc factors, determines the alcoholysis - hydrogen solution two-step degradation of lignin, the optimal process conditions: lignin alcoholysis under 50% methanol and NaOH catalyst in the solution, the lignin in methanol solution and 50% hydrogen solution under the Pd/C catalyst. In this process, the degradation of lignin yield can reach 42%.

Production of short-chain fatty acids from the biodegradation of wheat straw lignin by Aspergillus fumigatus.

PubMed

Baltierra-Trejo, Eduardo; Sánchez-Yáñez, Juan Manuel; Buenrostro-Delgado, Otoniel; Márquez-Benavides, Liliana

2015-11-01

The wheat straw lignin-rich fraction (WSLig-RF) can be used as a raw material for the production of metabolites for industrial use if ligninolytic mitosporic fungi are used for its biodegradation into aromatics and short-chain fatty acids (SCFAs, i.e., SCFA2-6). Although methods for the production of SCFA2-6 have been described previously, quantitative data of SCFA2-6 production have not been reported. The objectives of this study were to investigate the biodegradation of different concentrations of WSLig-RF by Aspergillus fumigatus and to identify whether SCFA2-6 production was dependent on the concentration of aromatics. A. fumigatus generated 2805mgL(-1) acetic acid when mixed with WSLig-RF at a concentration of 20gL(-1). Thus, aromatics are a substrate for the biosynthesis of SCFA2-6, and their production depends on the concentration of WSLig-RF aromatics. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lignin biosynthesis in wheat (Triticum aestivum L.): its response to waterlogging and association with hormonal levels.

PubMed

Nguyen, Tran-Nguyen; Son, SeungHyun; Jordan, Mark C; Levin, David B; Ayele, Belay T

2016-01-25

Lignin is an important structural component of plant cell wall that confers mechanical strength and tolerance against biotic and abiotic stressors; however it affects the use of biomass such as wheat straw for some industrial applications such as biofuel production. Genetic alteration of lignin quantity and quality has been considered as a viable option to overcome this problem. However, the molecular mechanisms underlying lignin formation in wheat biomass has not been studied. Combining molecular and biochemical approaches, the present study investigated the transcriptional regulation of lignin biosynthesis in two wheat cultivars with varying lodging characteristics and also in response to waterlogging. It also examined the association of lignin level in tissues with that of plant hormones implicated in the control of lignin biosynthesis. Analysis of lignin biosynthesis in the two wheat cultivars revealed a close association of lodging resistance with internode lignin content and expression of 4-coumarate:CoA ligase1 (4CL1), p-coumarate 3-hydroxylase1 (C3H1), cinnamoyl-CoA reductase2 (CCR2), ferulate 5-hydroxylase2 (F5H2) and caffeic acid O-methyltransferase2 (COMT2), which are among the genes highly expressed in wheat tissues, implying the importance of these genes in mediating lignin deposition in wheat stem. Waterlogging of wheat plants reduced internode lignin content, and this effect is accompanied by transcriptional repression of three of the genes characterized as highly expressed in wheat internode including phenylalanine ammonia-lyase6 (PAL6), CCR2 and F5H2, and decreased activity of PAL. Expression of the other genes was, however, induced by waterlogging, suggesting their role in the synthesis of other phenylpropanoid-derived molecules with roles in stress responses. Moreover, difference in internode lignin content between cultivars or change in its level due to waterlogging is associated with the level of cytokinin. Lodging resistance, tolerance against

The effect of particle size and amount of inoculum on fungal treatment of wheat straw and wood chips.

PubMed

van Kuijk, Sandra J A; Sonnenberg, Anton S M; Baars, Johan J P; Hendriks, Wouter H; Cone, John W

2016-01-01

The aim of this study was to optimize the fungal treatment of lignocellulosic biomass by stimulating the colonization. Wheat straw and wood chips were treated with Ceriporiopsis subvermispora and Lentinula edodes with various amounts of colonized millet grains (0.5, 1.5 or 3.0 % per g of wet weight of substrate) added to the substrates. Also, wheat straw and wood chips were chopped to either 0.5 or 2 cm. Effectiveness of the fungal treatment after 0, 2, 4, 6, or 8 wk of incubation was determined by changes in chemical composition, in vitro gas production (IVGP) as a measure for rumen degradability, and ergosterol content as a measure of fungal biomass. Incomplete colonization was observed for C. subvermispora treated wheat straw and L. edodes treated wood chips. The different particle sizes and amounts of inoculum tested, had no significant effects on the chemical composition and the IVGP of C. subvermispora treated wood chips. Particle size did influence L. edodes treatment of wheat straw. The L. edodes treatment of 2 cm wheat straw resulted in a more selective delignification and a higher IVGP than the smaller particles. Addition of 1.5 % or 3 % L. edodes inoculum to wheat straw resulted in more selective delignification and a higher IVGP than addition of 0.5 % inoculum. Particle size and amount of inoculum did not have an effect on C. subvermispora treatment of wood chips. At least 1.5 % L. edodes colonized millet grains should be added to 2 cm wheat straw to result in an increased IVGP and acid detergent lignin (ADL) degradation.

Isolation and Characterization of Gramineae and Fabaceae Soda Lignins

PubMed Central

Domínguez-Robles, Juan; Sánchez, Rafael; Espinosa, Eduardo; Savy, Davide; Mazzei, Pierluigi; Piccolo, Alessandro; Rodríguez, Alejandro

2017-01-01

Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus, could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.). In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR) and both liquid- and solid-state nuclear magnetic resonance spectroscopy (NMR) to analyse the chemical structure, and thermogravimetric analysis (TGA) for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p-coumarate (PCA), ferulate (FA) and cinnamyl aldehyde end-groups (J) were only detected in wheat isolated lignin. PMID:28165411

Isolation and Characterization of Gramineae and Fabaceae Soda Lignins.

PubMed

Domínguez-Robles, Juan; Sánchez, Rafael; Espinosa, Eduardo; Savy, Davide; Mazzei, Pierluigi; Piccolo, Alessandro; Rodríguez, Alejandro

2017-02-04

Some agricultural residues such as wheat or barley straw, as well as certain fast-growing plants like Leucaena leucocephala and Chamaecytisus proliferus , could be used as raw materials for the paper industry as an alternative to traditional plants (eucalyptus, pine, etc.). In the present study, four types of lignin obtained from the spent liquors produced by the pulping processes using the abovementioned feedstocks were isolated and characterized. Lignin samples were acquired through an acid precipitation from these spent liquors. The characterization of the precipitated lignin samples were performed using a Fourier transform infrared spectroscopy (FT-IR) and both liquid- and solid-state nuclear magnetic resonance spectroscopy (NMR) to analyse the chemical structure, and thermogravimetric analysis (TGA) for determining the thermal properties. Additionally, chemical composition of lignin fractions was also measured. Even though they were of different botanical origin, all the studied samples except for wheat straw lignin had a similar chemical composition and thermal behaviour, and identical chemical structure. Wheat straw lignin showed a greater amount of Klason lignin and lower carbohydrate content. Furthermore, this lignin sample showed a higher thermal stability and significantly different cross-peak patterns in the 2D-NMR experiments. The molecular structures corresponding to p -coumarate (PCA), ferulate (FA) and cinnamyl aldehyde end-groups (J) were only detected in wheat isolated lignin.

Energy assessment of second generation (2G) ethanol production from wheat straw in Indian scenario.

PubMed

Mishra, Archana; Kumar, Akash; Ghosh, Sanjoy

2018-03-01

Impact of second-generation ethanol (2G) use in transportation sector mainly depends upon energy efficiency of entire production process. The objective of present study was to determine energy efficiency of a potential lignocellulosic feedstock; wheat straw and its conversion into cellulosic ethanol in Indian scenario. Energy efficiency was determined by calculating Net energy ratio (NER), i.e. ratio of output energy obtained by ethanol and input energy used in ethanol production. Energy consumption and generation at each step is calculated briefly (11,837.35 MJ/ha during Indian dwarf irrigated variety of wheat crop production and 7.1148 MJ/kg straw during ethanol production stage). Total energy consumption is calculated as 8.2988 MJ/kg straw whereas energy generation from ethanol is 15.082 MJ/kg straw; resulting into NER > 1. Major portion of agricultural energy input is contributed by diesel and fertilisers whereas refining process of wheat straw feedstock to ethanol and by-products require mainly in the form of steam and electricity. On an average, 1671.8 kg water free ethanol, 930 kg lignin rich biomass (for combustion), and 561 kg C5-molasses (for fodder) per hectare are produced. Findings of this study, net energy ratio (1.81) and figure of merit (14.8028 MJ/nil kg carbon) proves wheat straw as highest energy efficient lignocellulosic feedstock for the country.

Oyster mushroom cultivation with rice and wheat straw.

PubMed

Zhang, Ruihong; Li, Xiujin; Fadel, J G

2002-05-01

Cultivation of the oyster mushroom, Pleurotus sajor-caju, on rice and wheat straw without nutrient supplementation was investigated. The effects of straw size reduction method and particle size, spawn inoculation level, and type of substrate (rice straw versus wheat straw) on mushroom yield, biological efficiency, bioconversion efficiency, and substrate degradation were determined. Two size reduction methods, grinding and chopping, were compared. The ground straw yielded higher mushroom growth rate and yield than the chopped straw. The growth cycles of mushrooms with the ground substrate were five days shorter than with the chopped straw for a similar particle size. However, it was found that when the straw was ground into particles that were too small, the mushroom yield decreased. With the three spawn levels tested (12%, 16% and 18%), the 12% level resulted in significantly lower mushroom yield than the other two levels. Comparing rice straw with wheat straw, rice straw yielded about 10% more mushrooms than wheat straw under the same cultivation conditions. The dry matter loss of the substrate after mushroom growth varied from 30.1% to 44.3%. The straw fiber remaining after fungal utilization was not as degradable as the original straw fiber, indicating that the fungal fermentation did not improve the feed value of the straw.

Lignin Films from Spruce, Eucalyptus, and Wheat Straw Studied with Electroacoustic and Optical Sensors: Effect of Composition and Electrostatic Screening on Enzyme Binding.

PubMed

Pereira, Antonio; Hoeger, Ingrid C; Ferrer, Ana; Rencoret, Jorge; Del Rio, José C; Kruus, Kristiina; Rahikainen, Jenni; Kellock, Miriam; Gutiérrez, Ana; Rojas, Orlando J

2017-04-10

Lignins were isolated from spruce, wheat straw, and eucalyptus by using the milled wood lignin (MWL) method. Functional groups and compositional analyses were assessed via 2D NMR and 31 P NMR to realize their effect on enzyme binding. Films of the lignins were fabricated and ellipsometry, atomic force microscopy, and water contact angle measurements were used for their characterization and to reveal the changes upon enzyme adsorption. Moreover, lignin thin films were deposited on quartz crystal microgravimetry (QCM) and surface plasmon (SPR) resonance sensors and used to gain further insights into the lignin-cellulase interactions. For this purpose, a commercial multicomponent enzyme system and a monocomponent Trichoderma reesei exoglucanase (CBH-I) were considered. Strong enzyme adsorption was observed on the various lignins but compared to the multicomponent cellulases, CBH-I displayed lower surface affinity and higher binding reversibility. This resolved prevalent questions related to the affinity of this enzyme with lignin. Remarkably, a strong correlation between enzyme binding and the syringyl/guaiacyl (S/G) ratio was found for the lignins, which presented a similar hydroxyl group content ( 31 P NMR): higher protein affinity was determined on isolated spruce lignin (99% G units), while the lowest adsorption occurred on isolated eucalyptus lignin (70% S units). The effect of electrostatic interactions in enzyme adsorption was investigated by SPR, which clearly indicated that the screening of charges allowed more extensive protein adsorption. Overall, this work furthers our understanding of lignin-cellulase interactions relevant to biomass that has been subjected to no or little pretreatment and highlights the widely contrasting effects of the nature of lignin, which gives guidance to improve lignocellulosic saccharification and related processes.

Enhanced the enzymatic hydrolysis efficiency of wheat straw after combined steam explosion and laccase pretreatment.

PubMed

Qiu, Weihua; Chen, Hongzhang

2012-08-01

Laccase, capable of selectively degrading lignin while keeping cellulose intact, has been widely applied for the modification and bio-bleaching of pulp. In this study Sclerotium sp. laccase (MSLac) was employed in combination with steam explosion to evaluate the effect of this treatment on cellulose hydrolysis. Combined steam explosion with laccase pretreatment enhanced the cellulose conversion rate of wheat straw no matter in the case of successive (MSLac-Cel) and simultaneous (MSLac+Cel) MSLac and cellulase hydrolysis. The highest cellulose conversion rate of 84.23% was obtained when steam-exploded wheat straw (SEWS) (1.3 MPa, 5 min) was treated by MSLac+Cel at a laccase loading of 0.55 U g(-1) substrate. FT-IR and SEM analyses indicated that MSLac oxidized the phenol and changed electron configuration of the ring, which contributed to loosening the compact wrap of lignin-carbohydrate complex and consequently enhancing the enzymatic hydrolysis efficiency of cellulose. This article provided a promising method for lignocellulose bio-pretreatment. Copyright © 2012 Elsevier Ltd. All rights reserved.

Size exclusion chromatography for the removal of pigments from extracellular ligninolytic enzyme extracts from decayed wheat straw.

PubMed

Shukla, Dharmendra; Patel, Bhavesh; Modi, Hasmukh; Vyas, Bharat Rajiv Manuel

2011-11-01

Solid-state fermentation of wheat straw was carried out by a native white rot basidiomycete Daedaleopsis flavida strain 5A. Extract prepared from the 12-day decayed wheat straw contained extracellular ligninolytic enzymes like manganese peroxidase (MnP), manganese-independent peroxidase (MIP), lignin peroxidase (LiP) and laccase along with straw-degraded products and pigments. Sephacryl S-200 size exclusion chromatography in 16/100 column was used for the separation of these ligninolytic enzymes and straw-degraded products and pigments. Recovery of pigment-free ligninolytic enzyme activities as protein was 40% of the total proteins loaded and specific LiP activity increased 34 fold after size exclusion chromatography. Thus accurate estimation of LiP by veratryl alcohol oxidation assay was possible only after the removal of interfering pigments. The reproducibility of size exclusion chromatography is adjudged satisfactory from the consistent results obtained after seven repetitive uses of matrices.

Visualization and Semiquantitative Study of the Distribution of Major Components in Wheat Straw in Mesoscopic Scale using Fourier Transform Infrared Microspectroscopic Imaging.

PubMed

Yang, Zengling; Mei, Jiaqi; Liu, Zhiqiang; Huang, Guangqun; Huang, Guan; Han, Lujia

2018-06-19

Understanding the biochemical heterogeneity of plant tissue linked to crop straw anatomy is attractive to plant researchers and researchers in the field of biomass refinery. This study provides an in situ analysis and semiquantitative visualization of major components distribution in internodal transverse sections of wheat straw based on Fourier transform infrared (FTIR) microspectroscopic imaging, with a fast non-negativity-constrained least squares (fast NNLS) fitting. This paper investigates changes in biochemical components of tissue during stages of elongation, booting, heading, flowering, grain-filling, milk-ripening, dough, and full-ripening. Visualization analysis was carried out with reference spectra for five components (microcrystalline cellulose, xylan, lignin, pectin, and starch) of wheat straw. Our result showed that (a) the cellulose and lignin distribution is consistent with that from tissue-dyeing with safranin O-fast green and (b) the distribution of cellulose, lignin, and starch is consistent with chemical images for characteristic wavelength at 1432, 1507, and 987 cm -1 , respectively, showing no interference from the other components analyzed. With the validation from biochemical images using characteristic wavelength and tissue-dyeing techniques, further semiquantitative analysis in local tissues based on fast NNLS was carried out, and the result showed that (a) the contents of cellulose in various tissues are very different, with most in parenchyma tissue and least in the epidermis and (b) during plant development, the fluctuation of each component in tissues follows nearly the same trend, especially within vascular bundles and parenchyma tissue. Thus, FTIR microspectroscopic imaging combined with suitable chemometric methods can be successfully applied to study chemical distributions within the internodes transverse sections of wheat straw, providing semiquantitative chemical information.

Flocculation of high purity wheat straw soda lignin.

PubMed

Piazza, G J; Lora, J H; Garcia, R A

2014-01-01

In industrial process, acidification causes non-sulfonated lignin insolubility. The flocculants poly(diallyldimethylammonium chloride) (pDADMAC) and bovine blood (BB) also caused lignin insolubility while cationic polyacrylamide, chitosan, and soy protein PF 974 were ineffective. Turbidity determined optimal flocculant, but turbidity magnitude with BB was greater than expected. pDADMAC caused negative lignin Zeta potential to became positive, but BB-lignin Zeta potential was always negative. Insoluble lignin did not gravity sediment, and flocculant-lignin mixtures were centrifuged. Pellet and supernatant dry mass and corrected spectroscopic results were in good agreement for optimal pDADMAC and BB. Spectroscopy showed 87-92% loss of supernatant lignin. Nitrogen analysis showed BB concentrated in the pellet until the pellet became saturated with BB. Subtracting ash and BB mass from pellet and supernatant mass confirmed optimal BB. Low levels of alum caused increased lignin flocculation at lower levels of pDADMAC and BB, but alum did not affect optimal flocculant. Published by Elsevier Ltd.

Selection of strains of Lentinula edodes and Lentinula boryana adapted for efficient mycelial growth on wheat straw.

PubMed

Mata, G; Delpech, P; Savoie, J M

2001-09-01

Mycelial growth rates are presented for 11 strains of Lentinula edodes and six strains of Lentinula boryana cultivated on solid media: derived from malt extract (MEA); malt yeast extract (YMEA); and, YMEA plus soluble lignin derivatives (YMEA+WSLD). The results were compared with data for mycelial growth rates, of the same strains cultivated on substrates derived from wheat straw treated at different temperatures (50, 65, 75 and autoclaving at 121 degrees C). In general, the addition of WSLD significantly reduced mycelial growth rates in both species. The greatest mycelial growth rate was obtained on sterilized straw at 121 degrees C for the majority of strains. However, this growth was not significantly different from that obtained at 75 degrees C. L. edodes showed greater growth rates than L. boryana. The feasibility of using estimates of mycelial growth rate on YMEA and YMEA+WSLD are discussed as possible indicators of a strain's potential for mycelial growth on substrates derived from wheat straw.

Growth of Pleurotus ostreatus on wheat straw and wheat-grain-based media: Biochemical aspects and preparation of mushroom inoculum.

PubMed

Sainos, E; Díaz-Godínez, G; Loera, O; Montiel-González, A M; Sánchez, C

2006-10-01

Mycelial growth, intracellular activity of proteases, laccases and beta-1,3-glucanases, and cytoplasmic protein were evaluated in the vegetative phase of Pleurotus ostreatus grown on wheat straw and in wheat-grain-based media in Petri dishes and in bottles. The productivity of the wheat straw and wheat-grain-based spawn in cylindrical polyethylene bags containing 5 kg of chopped straw was also determined. We observed high activity of proteases and high content of intracellular protein in cultures grown on wheat straw. This suggests that the proteases are not secreted into the medium and that the protein is an important cellular reserve. On the contrary, cultures grown on wheat straw secreted laccases into the medium, which could be induced by this substrate. P. ostreatus grown on media prepared with a combination of wheat straw and wheat grain showed a high radial growth rate in Petri dishes and a high level of mycelial growth in bottles. The productivities of wheat straw and wheat-grain-based spawn were similar. Our results show that cheaper and more productive mushroom spawn can be prepared by developing the mycelium on wheat straw and wheat-grain-based substrates.

Bioprocessing of wheat and paddy straw for their nutritional up-gradation.

PubMed

Sharma, Rakesh Kumar; Arora, Daljit Singh

2014-07-01

Solid-state bioprocessing of agricultural residues seems to be an emerging and effective method for the production of high quality animal feed. Seven strains of white-rot fungi were selected to degrade wheat and paddy straw (PS) under solid-state conditions. Degradation of different components, i.e., hemicellulose, cellulose and lignin was evaluated along with nutritional parameters including; in vitro digestibility, crude protein, amino acids, total phenolic contents (TPC) etc. Effect of nitrogen-rich supplements on degradation of lignocellulosics was evaluated using two best selected fungal strains (Phlebia brevispora and Phlebia floridensis). The best selected conditions were used to upscale the process up to 200 g batches of wheat and PS. Lignin was selectively degraded up to 30 % with a limited loss of 11-12 % in total organic matter. Finally, the degraded agro-residues demonstrated 50-62 % enhancement in their digestibility. Two-threefold enhancement in other nutritional quality (amino acids, TPCs and antioxidant activity) fortifies the process. Thus the method is quite helpful to design an effective solid-state fermentation system to improve the nutritive quality of agricultural residues by simultaneous production of lignocellulolytic enzyme production and antioxidants.

Flocculation of high purity wheat straw soda lignin

USDA-ARS?s Scientific Manuscript database

Flocculant action on lignocellulose mixtures has been studied, but flocculant action on purified sulfur-free lignin has not been reported. In the last step of the industrial process, the purified lignin solution is acidified with sulfuric acid which causes the lignin to become insoluble. The feasi...

Phosphomolybdic acid and ferric iron as efficient electron mediators for coupling biomass pretreatment to produce bioethanol and electricity generation from wheat straw

Treesearch

Yi Ding; Bo Du; Xuebing Zhao; J.Y. Zhu; Dehua Liu

2017-01-01

Phosphomolybdic acid (PMo12) was used as an electron mediator and proton carrier to mediate biomass pretreatment for ethanol production and electricity generation from wheat straw. In the pretreatment, lignin was oxidized anaerobically by PMo12 with solubilization of a fraction of hemicelluloses, and the PMo12...

The Effect of Plant Source on the Structural Properties of Lignin-based Polyurethane Blends

NASA Astrophysics Data System (ADS)

Lang, Jason; Dadmun, Mark

The development of polyurethane materials based on incorporating lignin from a variety of plant sources (softwood, hardwood, and non-wood) were synthesized. Further experiments study the physical properties of the resulting lignin-based polyurethane as a function of the lignin structure, which varies with plant source. Here, we report the effect that internal crosslinking of the lignin structure has on the modulus, hardness, glass transition temperature, and thermal decomposition of the synthesized lignin-based polyurethane composites. The lignins used in this work were a softwood kraft lignin, hardwood lignosulfonate, and a wheat straw soda lignin. The lignin, acting as a polyol and the hardblock segment, reacts with TDI-endcapped PPG (2,300 MN) as the rubbery softblock component to produce lignin-based polyurethanes with varying lignin content (10, 20, 30, 40, 50, and 60 wt%). Results show that the wheat straw lignin provides the superior mechanical properties and thermal resistance. These properties are correlated to the two-phase morphology of the resultant polyurethane.

Rapid estimation of sugar release from winter wheat straw during bioethanol production using FTIR-photoacoustic spectroscopy

DOE PAGES

Bekiaris, Georgios; Lindedam, Jane; Peltre, Clément; ...

2015-06-18

Complexity and high cost are the main limitations for high-throughput screening methods for the estimation of the sugar release from plant materials during bioethanol production. In addition, it is important that we improve our understanding of the mechanisms by which different chemical components are affecting the degradability of plant material. In this study, Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was combined with advanced chemometrics to develop calibration models predicting the amount of sugars released after pretreatment and enzymatic hydrolysis of wheat straw during bioethanol production, and the spectra were analysed to identify components associated with recalcitrance. A total of 1122more » wheat straw samples from nine different locations in Denmark and one location in the United Kingdom, spanning a large variation in genetic material and environmental conditions during growth, were analysed. The FTIR-PAS spectra of non-pretreated wheat straw were correlated with the measured sugar release, determined by a high-throughput pretreatment and enzymatic hydrolysis (HTPH) assay. A partial least square regression (PLSR) calibration model predicting the glucose and xylose release was developed. The interpretation of the regression coefficients revealed a positive correlation between the released glucose and xylose with easily hydrolysable compounds, such as amorphous cellulose and hemicellulose. Additionally, we observed a negative correlation with crystalline cellulose and lignin, which inhibits cellulose and hemicellulose hydrolysis. FTIR-PAS was used as a reliable method for the rapid estimation of sugar release during bioethanol production. The spectra revealed that lignin inhibited the hydrolysis of polysaccharides into monomers, while the crystallinity of cellulose retarded its hydrolysis into glucose. Amorphous cellulose and xylans were found to contribute significantly to the released amounts of glucose and xylose

Rapid estimation of sugar release from winter wheat straw during bioethanol production using FTIR-photoacoustic spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bekiaris, Georgios; Lindedam, Jane; Peltre, Clément

Complexity and high cost are the main limitations for high-throughput screening methods for the estimation of the sugar release from plant materials during bioethanol production. In addition, it is important that we improve our understanding of the mechanisms by which different chemical components are affecting the degradability of plant material. In this study, Fourier transform infrared photoacoustic spectroscopy (FTIR-PAS) was combined with advanced chemometrics to develop calibration models predicting the amount of sugars released after pretreatment and enzymatic hydrolysis of wheat straw during bioethanol production, and the spectra were analysed to identify components associated with recalcitrance. A total of 1122more » wheat straw samples from nine different locations in Denmark and one location in the United Kingdom, spanning a large variation in genetic material and environmental conditions during growth, were analysed. The FTIR-PAS spectra of non-pretreated wheat straw were correlated with the measured sugar release, determined by a high-throughput pretreatment and enzymatic hydrolysis (HTPH) assay. A partial least square regression (PLSR) calibration model predicting the glucose and xylose release was developed. The interpretation of the regression coefficients revealed a positive correlation between the released glucose and xylose with easily hydrolysable compounds, such as amorphous cellulose and hemicellulose. Additionally, we observed a negative correlation with crystalline cellulose and lignin, which inhibits cellulose and hemicellulose hydrolysis. FTIR-PAS was used as a reliable method for the rapid estimation of sugar release during bioethanol production. The spectra revealed that lignin inhibited the hydrolysis of polysaccharides into monomers, while the crystallinity of cellulose retarded its hydrolysis into glucose. Amorphous cellulose and xylans were found to contribute significantly to the released amounts of glucose and xylose

Quantification of Lignin and Its Structural Features in Plant Biomass Using 13C Lignin as Internal Standard for Pyrolysis-GC-SIM-MS.

PubMed

van Erven, Gijs; de Visser, Ries; Merkx, Donny W H; Strolenberg, Willem; de Gijsel, Peter; Gruppen, Harry; Kabel, Mirjam A

2017-10-17

Understanding the mechanisms underlying plant biomass recalcitrance at the molecular level can only be achieved by accurate analyses of both the content and structural features of the molecules involved. Current quantification of lignin is, however, majorly based on unspecific gravimetric analysis after sulfuric acid hydrolysis. Hence, our research aimed at specific lignin quantification with concurrent characterization of its structural features. Hereto, for the first time, a polymeric 13 C lignin was used as internal standard (IS) for lignin quantification via analytical pyrolysis coupled to gas chromatography with mass-spectrometric detection in selected ion monitoring mode (py-GC-SIM-MS). In addition, relative response factors (RRFs) for the various pyrolysis products obtained were determined and applied. First, 12 C and 13 C lignin were isolated from nonlabeled and uniformly 13 C labeled wheat straw, respectively, and characterized by heteronuclear single quantum coherence (HSQC), nuclear magnetic resonance (NMR), and py-GC/MS. The two lignin isolates were found to have identical structures. Second, 13 C-IS based lignin quantification by py-GC-SIM-MS was validated in reconstituted biomass model systems with known contents of the 12 C lignin analogue and was shown to be extremely accurate (>99.9%, R 2 > 0.999) and precise (RSD < 1.5%). Third, 13 C-IS based lignin quantification was applied to four common poaceous biomass sources (wheat straw, barley straw, corn stover, and sugar cane bagasse), and lignin contents were in good agreement with the total gravimetrically determined lignin contents. Our robust method proves to be a promising alternative for the high-throughput quantification of lignin in milled biomass samples directly and simultaneously provides a direct insight into the structural features of lignin.

Comparative culturing of Pleurotus spp. on coffee pulp and wheat straw: biomass production and substrate biodegradation.

PubMed

Salmones, Dulce; Mata, Gerardo; Waliszewski, Krzysztof N

2005-03-01

The results of the cultivation of six strains of Pleurotus (P. djamor (2), P. ostreatus (2) and P. pulmonarius (2)) on coffee pulp and wheat straw are presented. Metabolic activity associated with biomass of each strain was determined, as well as changes in lignin and polysaccharides (cellulose and hemicellulose), phenolic and caffeine contents in substrate samples colonized for a period of up to 36 days. Analysis were made of changes during the mycelium incubation period (16 days) and throughout different stages of fructification. Greater metabolic activity was observed in the wheat straw samples, with a significant increase between 4 and 12 days of incubation. The degradation of polysaccharide compounds was associated with the fruiting stage, while the reduction in phenolic contents was detected in both substrates samples during the first eight days of incubation. A decrease was observed in caffeine content of the coffee pulp samples during fruiting stage, which could mean that some caffeine accumulates in the fruiting bodies.

A solid state fungal fermentation-based strategy for the hydrolysis of wheat straw.

PubMed

Pensupa, Nattha; Jin, Meng; Kokolski, Matt; Archer, David B; Du, Chenyu

2013-12-01

This paper reports a solid-state fungal fermentation-based pre-treatment strategy to convert wheat straw into a fermentable hydrolysate. Aspergillus niger was firstly cultured on wheat straw for production of cellulolytic enzymes and then the wheat straw was hydrolyzed by the enzyme solution into a fermentable hydrolysate. The optimum moisture content and three wheat straw modification methods were explored to improve cellulase production. At a moisture content of 89.5%, 10.2 ± 0.13 U/g cellulase activity was obtained using dilute acid modified wheat straw. The addition of yeast extract (0.5% w/v) and minerals significantly improved the cellulase production, to 24.0 ± 1.76 U/g. The hydrolysis of the fermented wheat straw using the fungal culture filtrate or commercial cellulase Ctec2 was performed, resulting in 4.34 and 3.13 g/L glucose respectively. It indicated that the fungal filtrate harvested from the fungal fermentation of wheat straw contained a more suitable enzyme mixture than the commercial cellulase. Copyright © 2013 The Authors. Published by Elsevier Ltd.. All rights reserved.

Compostability and biodegradation study of PLA-wheat straw and PLA-soy straw based green composites in simulated composting bioreactor.

PubMed

Pradhan, Ranjan; Misra, Manjusri; Erickson, Larry; Mohanty, Amar

2010-11-01

A laboratory scale simulated composting facility (as per ASTM D 5338) was designed and utilized to determine and evaluate the extent of degradation of polylactic acid (PLA), untreated wheat and soy straw and injection moulded composites of PLA-wheat straw (70:30) and PLA-soy straw (70:30). The outcomes of the study revealed the suitability of the test protocol, validity of the test system and defined the compostability of the composites of PLA with unmodified natural substrate. The study would help to design composites using modified soy straw and wheat straw as reinforcement/filler to satisfy ASTM D 6400 specifications. Copyright 2010 Elsevier Ltd. All rights reserved.

Characterization of lignins isolated with alkali from the hydrothermal or dilute-acid pretreated rapeseed straw during bioethanol production.

PubMed

Chen, Bo-Yang; Zhao, Bao-Cheng; Li, Ming-Fei; Sun, Run-Cang

2018-01-01

A better understanding of the lignin in the straw of rapeseed, Brassica campestris L., is a prerequisite for promoting the biorefinery industry of rapeseed. Two different methods for fractionating lignin from rapeseed straw were proposed in this study. Lignin in the raw material was isolated with alkaline solution and recovered by acid precipitation. A comparison between two lignin preparations obtained from two different methods has been made in terms of yield and purity. The structural features were investigated by gel permeation chromatography, FT-IR spectroscopy, 2D-HSQC NMR and 31 P NMR. Taking into consideration of the yield and purity, the proposed methods are effective for extracting lignin. NMR results showed that syringyl (S) was the predominant unit over guaiacyl (G) or p-hydroxyphenyl (H) units in the lignin preparations, and linkages β-O-4', β-β' and β-5' were also identified and quantified by NMR techniques. This study demonstrated that the combination of hydrothermal or dilute-acid pretreatment and alkaline process could efficiently isolate the lignins from the rapeseed straw to further applications for industries. It was found that the enzymatic hydrolysis of the two-step pretreated rapeseed straw increased 5.9 times than the straw without treatment, which is benefit for bioethanol production from rapeseed straw. Copyright © 2017 Elsevier B.V. All rights reserved.

Structural elucidation and antioxidant activity of lignin isolated from rice straw and alkali‑oxygen black liquor.

PubMed

Jiang, Bo; Zhang, Yu; Gu, Lihui; Wu, Wenjuan; Zhao, Huifang; Jin, Yongcan

2018-05-17

Alkali‑oxygen cooking of lignocellulose offers lignin many structural properties and bioactivities for biorefinery. In this work, milled wood lignin (MWL) and alkali‑oxygen lignin (AOL) were isolated from rice straw and alkali‑oxygen black liquor, respectively. The lignin structure was characterized by spectroscopy and wet chemistry. Antioxidant activity of lignins was assessed by DPPH·and ABTS scavenging ability assay. Results showed the oxidization and condensation of lignin occurred during alkali‑oxygen cooking. The p-hydroxyphenyl was more easily removed from rice straw than guaiacyl and syringyl units. The ester or ether linkages derived from hydroxycynnamic acids, and the main interunit linkages, i.e. β-O-4' bonds, were mostly cleaved. Lignin-xylan complex had high reactivity under alkali‑oxygen condition. Tricin, incorporated into lignin, was detected in MWL but was absent in AOL. Nitrobenzene oxidation showed MWL can well represent the protolignin of rice straw, and the products yield decreased dramatically after alkali‑oxygen cooking. AOL had higher radical scavenging ability than MWL indicating alkali‑oxygen cooking was an effective pathway for the enhancement of antioxidant activity of lignin. Copyright © 2018 Elsevier B.V. All rights reserved.

Quantification of Lignin and Its Structural Features in Plant Biomass Using 13C Lignin as Internal Standard for Pyrolysis-GC-SIM-MS

PubMed Central

2017-01-01

Understanding the mechanisms underlying plant biomass recalcitrance at the molecular level can only be achieved by accurate analyses of both the content and structural features of the molecules involved. Current quantification of lignin is, however, majorly based on unspecific gravimetric analysis after sulfuric acid hydrolysis. Hence, our research aimed at specific lignin quantification with concurrent characterization of its structural features. Hereto, for the first time, a polymeric 13C lignin was used as internal standard (IS) for lignin quantification via analytical pyrolysis coupled to gas chromatography with mass-spectrometric detection in selected ion monitoring mode (py-GC-SIM-MS). In addition, relative response factors (RRFs) for the various pyrolysis products obtained were determined and applied. First, 12C and 13C lignin were isolated from nonlabeled and uniformly 13C labeled wheat straw, respectively, and characterized by heteronuclear single quantum coherence (HSQC), nuclear magnetic resonance (NMR), and py-GC/MS. The two lignin isolates were found to have identical structures. Second, 13C-IS based lignin quantification by py-GC-SIM-MS was validated in reconstituted biomass model systems with known contents of the 12C lignin analogue and was shown to be extremely accurate (>99.9%, R2 > 0.999) and precise (RSD < 1.5%). Third, 13C-IS based lignin quantification was applied to four common poaceous biomass sources (wheat straw, barley straw, corn stover, and sugar cane bagasse), and lignin contents were in good agreement with the total gravimetrically determined lignin contents. Our robust method proves to be a promising alternative for the high-throughput quantification of lignin in milled biomass samples directly and simultaneously provides a direct insight into the structural features of lignin. PMID:28926698

White-rot fungal pretreatment of wheat straw with Phanerochaete chrysosporium for biohydrogen production: simultaneous saccharification and fermentation.

PubMed

Zhi, Zelun; Wang, Hui

2014-07-01

This paper demonstrates biohydrogen production was enhanced by white-rot fungal pretreatment of wheat straw (WS) through simultaneous saccharification and fermentation (SSF). Wheat straw was pretreated by Phanerochaete chrysosporium at 30 °C under solid state fermentation for 12 days, and lignin was removed about 28.5 ± 1.3 %. Microscopic structure observation combined thermal gravity and differential thermal gravity analysis further showed that the lignocellulose structure obviously disrupted after fungal pretreatment. Subsequently, the pretreated WS and crude cellulases prepared from Trichoderma atroviride were applied in SSF for hydrogen production using Clostridium perfringens. The maximum hydrogen yield was obtained to be 78.5 ± 3.4 ml g(-1)-pretreated WS, which was about 1.8-fold than the unpretreated group. Furthermore, the modified Gompertz model was applied study the progress of cumulative H(2) production. This work developed a novel bio-approach to improve fermentative H(2) yield from lignocellulosic biomass.

Composition, texture and methane potential of cellulosic residues from Lewis acids organosolv pulping of wheat straw.

PubMed

Constant, Sandra; Barakat, Abdellatif; Robitzer, Mike; Di Renzo, Francesco; Dumas, Claire; Quignard, Françoise

2016-09-01

Cellulosic pulps have been successfully isolated from wheat straw through a Lewis acids organosolv treatment. The use of Lewis acids with different hardness produced pulps with different delignification degrees. The cellulosic residue was characterised by chemical composition, X-ray diffraction, FT-IR spectroscopy, N2 physisorption, scanning electron microscopy and potential for anaerobic digestibility. Surface area and pore volume increased with the hardness of the Lewis acid, in correspondence with the decrease of the amount of lignin and hemicellulose in the pulp. The non linearity of the correlation between porosity and composition suggests that an agglomeration of cellulose fibrils occurs in the early stages of pulping. All organosolv pulps presented a significantly higher methane potential than the parent straw. A methane evolution of 295Ncm(3)/g OM was reached by a moderate improvement of the accessibility of the native straw. Copyright © 2016 Elsevier Ltd. All rights reserved.

One-step process of hydrothermal and alkaline treatment of wheat straw for improving the enzymatic saccharification.

PubMed

Sun, Shaolong; Zhang, Lidan; Liu, Fang; Fan, Xiaolin; Sun, Run-Cang

2018-01-01

To increase the production of bioethanol, a two-step process based on hydrothermal and dilute alkaline treatment was applied to reduce the natural resistance of biomass. However, the process required a large amount of water and a long operation time due to the solid/liquid separation before the alkaline treatment, which led to decrease the pure economic profit for production of bioethanol. Therefore, four one-step processes based on order of hydrothermal and alkaline treatment have been developed to enhance concentration of glucose of wheat straw by enzymatic saccharification. The aim of the present study was to systematically evaluated effect for different one-step processes by analyzing the physicochemical properties (composition, structural change, crystallinity, surface morphology, and BET surface area) and enzymatic saccharification of the treated substrates. In this study, hemicelluloses and lignins were removed from wheat straw and the morphologic structures were destroyed to various extents during the four one-step processes, which were favorable for cellulase absorption on cellulose. A positive correlation was also observed between the crystallinity and enzymatic saccharification rate of the substrate under the conditions given. The surface area of the substrate was positively related to the concentration of glucose in this study. As compared to the control (3.0 g/L) and treated substrates (11.2-14.6 g/L) obtained by the other three one-step processes, the substrate treated by one-step process based on successively hydrothermal and alkaline treatment had a maximum glucose concentration of 18.6 g/L, which was due to the high cellulose concentration and surface area for the substrate, accompanying with removal of large amounts of lignins and hemicelluloses. The present study demonstrated that the order of hydrothermal and alkaline treatment had significant effects on the physicochemical properties and enzymatic saccharification of wheat straw. The one

Cellulase production using different streams of wheat grain- and wheat straw-based ethanol processes.

PubMed

Gyalai-Korpos, Miklós; Mangel, Réka; Alvira, Pablo; Dienes, Dóra; Ballesteros, Mercedes; Réczey, Kati

2011-07-01

Pretreatment is a necessary step in the biomass-to-ethanol conversion process. The side stream of the pretreatment step is the liquid fraction, also referred to as the hydrolyzate, which arises after the separation of the pretreated solid and is composed of valuable carbohydrates along with compounds that are potentially toxic to microbes (mainly furfural, acetic acid, and formic acid). The aim of our study was to utilize the liquid fraction from steam-exploded wheat straw as a carbon source for cellulase production by Trichoderma reesei RUT C30. Results showed that without detoxification, the fungus failed to utilize any dilution of the hydrolyzate; however, after a two-step detoxification process, it was able to grow on a fourfold dilution of the treated liquid fraction. Supplementation of the fourfold-diluted, treated liquid fraction with washed pretreated wheat straw or ground wheat grain led to enhanced cellulase (filter paper) activity. Produced enzymes were tested in hydrolysis of washed pretreated wheat straw. Supplementation with ground wheat grain provided a more efficient enzyme mixture for the hydrolysis by means of the near-doubled β-glucosidase activity obtained.

Development of novel assays for lignin degradation: comparative analysis of bacterial and fungal lignin degraders.

PubMed

Ahmad, Mark; Taylor, Charles R; Pink, David; Burton, Kerry; Eastwood, Daniel; Bending, Gary D; Bugg, Timothy D H

2010-05-01

Two spectrophotometric assays have been developed to monitor breakdown of the lignin component of plant lignocellulose: a continuous fluorescent assay involving fluorescently modified lignin, and a UV-vis assay involving chemically nitrated lignin. These assays have been used to analyse lignin degradation activity in bacterial and fungal lignin degraders, and to identify additional soil bacteria that show activity for lignin degradation. Two soil bacteria known to act as aromatic degraders, Pseudomonas putida and Rhodococcus sp. RHA1, consistently showed activity in these assays, and these strains were shown in a small scale experiment to breakdown lignocellulose, producing a number of monocyclic phenolic products. Using milled wood lignin prepared from wheat straw, pine, and miscanthus, some bacterial lignin degraders were found to show specificity for lignin type. These assays could be used to identify novel lignin degraders for breakdown of plant lignocellulose.

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

PubMed

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.

Bioethanol and lipid production from the enzymatic hydrolysate of wheat straw after furfural extraction.

PubMed

Brandenburg, Jule; Poppele, Ieva; Blomqvist, Johanna; Puke, Maris; Pickova, Jana; Sandgren, Mats; Rapoport, Alexander; Vedernikovs, Nikolajs; Passoth, Volkmar

2018-07-01

This study investigates biofuel production from wheat straw hydrolysate, from which furfural was extracted using a patented method developed at the Latvian State Institute of Wood Chemistry. The solid remainder after furfural extraction, corresponding to 67.6% of the wheat straw dry matter, contained 69.9% cellulose of which 4% was decomposed during the furfural extraction and 26.3% lignin. Enzymatic hydrolysis released 44% of the glucose monomers in the cellulose. The resulting hydrolysate contained mainly glucose and very little amount of acetic acid. Xylose was not detectable. Consequently, the undiluted hydrolysate did not inhibit growth of yeast strains belonging to Saccharomyces cerevisiae, Lipomyces starkeyi, and Rhodotorula babjevae. In the fermentations, average final ethanol concentrations of 23.85 g/l were obtained, corresponding to a yield of 0.53 g ethanol per g released glucose. L. starkeyi generated lipids with a rate of 0.08 g/h and a yield of 0.09 g per g consumed glucose. R. babjevae produced lipids with a rate of 0.18 g/h and a yield of 0.17 per g consumed glucose. In both yeasts, desaturation increased during cultivation. Remarkably, the R. babjevae strain used in this study produced considerable amounts of heptadecenoic, α,- and γ-linolenic acid.

Heat and microbial treatments for nutritional upgrading of wheat straw

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milstein, O.; Vered, Y.; Sharma, A.

1986-03-01

The ligninolytic activities of four cellulolytic organisms were compared using straw. Only Aspergillus japonicus and Polyporous versicolor appreciably degraded lignin with A. japonicus yielding the most protein. In solid culture, most protein was produced by P. versicolor, closely followed by A. japonicus. Pertreatment of the straw by hot water facilitated biodegradation and protein production. The nutritional value of the residual straw was also increased by some fungal cultures. The greatest amount of degradable polysaccharide in the straw was made available by A. japonicus in liquid media and Pleurotus ostreatus in solid media. 29 references.

Comparison of different pretreatment strategies for enzymatic hydrolysis of wheat and barley straw.

PubMed

Rosgaard, Lisa; Pedersen, Sven; Meyer, Anne S

2007-12-01

In biomass-to-ethanol processes a physico-chemical pretreatment of the lignocellulosic biomass is a critical requirement for enhancing the accessibility of the cellulose substrate to enzymatic attack. This report evaluates the efficacy on barley and wheat straw of three different pretreatment procedures: acid or water impregnation followed by steam explosion versus hot water extraction. The pretreatments were compared after enzyme treatment using a cellulase enzyme system, Celluclast 1.5 L from Trichoderma reesei, and a beta-glucosidase, Novozyme 188 from Aspergillus niger. Barley straw generally produced higher glucose concentrations after enzymatic hydrolysis than wheat straw. Acid or water impregnation followed by steam explosion of barley straw was the best pretreatment in terms of resulting glucose concentration in the liquid hydrolysate after enzymatic hydrolysis. When the glucose concentrations obtained after enzymatic hydrolyses were related to the potential glucose present in the pretreated residues, the highest yield, approximately 48% (g g-1), was obtained with hot water extraction pretreatment of barley straw; this pretreatment also produced highest yields for wheat straw, producing a glucose yield of approximately 39% (g g-1). Addition of extra enzyme (Celluclast 1.5 L+Novozyme 188) during enzymatic hydrolysis resulted in the highest total glucose concentrations from barley straw, 32-39 g L-1, but the relative increases in glucose yields were higher on wheat straw than on barley straw. Maldi-TOF MS analyses of supernatants of pretreated barley and wheat straw samples subjected to acid and water impregnation, respectively, and steam explosion, revealed that the water impregnated + steam-exploded samples gave a wider range of pentose oligomers than the corresponding acid-impregnated samples.

History of adaptation determines short-term shifts in performance and community structure of hydrogen-producing microbial communities degrading wheat straw.

PubMed

Valdez-Vazquez, Idania; Morales, Ana L; Escalante, Ana E

2017-11-01

This study addresses the question of ecological interest for the determination of structure and diversity of microbial communities that degrade lignocellulosic biomasses to produce biofuels. Two microbial consortia with different history, native of wheat straw (NWS) and from a methanogenic digester (MD) fed with cow manure, were contrasted in terms of hydrogen performance, substrate disintegration and microbial diversity. NWS outperformed the hydrogen production rate of MD. Microscopic images revealed that NWS acted on the cuticle and epidermis, generating cellulose strands with high crystallinity, while MD degraded deeper layers, equally affecting all polysaccharides. The bacterial composition markedly differed according to the inocula origin. NWS almost solely comprised hydrogen producers of the phyla Firmicutes and Proteobacteria, with 38% members of Enterococcus. After hydrogen fermentation, NWS comprised 8% Syntrophococcus, an acetogen that cleaves aryl ethers of constituent groups on the aromatic components of lignin. Conversely, MD comprised thirteen phyla, primarily including Firmicutes with H 2 -producing members, and Bacteroidetes with non-H 2 -producing members, which reduced the hydrogen performance. Overall, the results of this study provide clear evidence that the history of adaptation of NWS enhanced the hydrogen performance from untreated wheat straw. Further, native wheat straw communities have the potential to refine cellulose fibers and produce biofuels simultaneously. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Temporal changes of the bacterial community colonizing wheat straw in the cow rumen.

PubMed

Jin, Wei; Wang, Ying; Li, Yuanfei; Cheng, Yanfen; Zhu, Weiyun

2018-04-01

This study used Miseq pyrosequencing and scanning electron microscopy to investigate the temporal changes in the bacterial community tightly attached to wheat straw in the cow rumen. The wheat straw was incubated in the rumens and samples were recovered at various times. The wheat straw degradation exhibited three phases: the first degradation phase occurred within 0.5 h, and the second degradation phase occurred after 6 h, with a stalling phase occurring between 0.5 and 6 h. Scanning electron microscopy revealed the colonization of the microorganisms on the wheat straw over time. The bacterial communities at 0.5, 6, 24, and 72 h were determined, corresponding to the degradation phases. Firmicutes and Bacteroidetes were the two most dominant phyla in the bacterial communities at the four time points. Principal coordinate analysis (PCoA) showed that the bacterial communities at the four time points were distinct from each other. The wheat straw-associated bacteria stabilized at the phylum level after 0.5 h of rumen incubation, and only modest phylum-level and family-level changes were observed for most taxa between 0.5 h and 72 h. The relative abundance of the dominant genera, Butyrivibrio, Coprococcus, Ruminococcus, Succiniclasticum, Clostridium, Prevotella, YRC22, CF231, and Treponema, changed significantly over time (P < .05). However, at the genus level, unclassified taxa accounted for 70.3% ± 6.1% of the relative abundance, indicating their probable importance in the degradation of wheat straw as well as in the temporal changes of the bacterial community. Thus, understanding the function of these unclassified taxa is of great importance for targeted improvement of forage use efficiency in ruminants. Collectively, our results revealed distinct degradation phases of wheat straw and corresponding changes in the colonized bacterial community. Copyright © 2018 Elsevier Ltd. All rights reserved.

Production of bioethanol from wheat straw: An overview on pretreatment, hydrolysis and fermentation.

PubMed

Talebnia, Farid; Karakashev, Dimitar; Angelidaki, Irini

2010-07-01

Wheat straw is an abundant agricultural residue with low commercial value. An attractive alternative is utilization of wheat straw for bioethanol production. However, production costs based on the current technology are still too high, preventing commercialization of the process. In recent years, progress has been made in developing more effective pretreatment and hydrolysis processes leading to higher yield of sugars. The focus of this paper is to review the most recent advances in pretreatment, hydrolysis and fermentation of wheat straw. Based on the type of pretreatment method applied, a sugar yield of 74-99.6% of maximum theoretical was achieved after enzymatic hydrolysis of wheat straw. Various bacteria, yeasts and fungi have been investigated with the ethanol yield ranging from 65% to 99% of theoretical value. So far, the best results with respect to ethanol yield, final ethanol concentration and productivity were obtained with the native non-adapted Saccharomyses cerevisiae. Some recombinant bacteria and yeasts have shown promising results and are being considered for commercial scale-up. Wheat straw biorefinery could be the near-term solution for clean, efficient and economically-feasible production of bioethanol as well as high value-added products. Copyright 2009 Elsevier Ltd. All rights reserved.

Adsorption of β-glucosidases in two commercial preparations onto pretreated biomass and lignin

PubMed Central

2013-01-01

Background Enzyme recycling is a method to reduce the production costs for advanced bioethanol by lowering the overall use of enzymes. Commercial cellulase preparations consist of many different enzymes that are important for efficient and complete cellulose (and hemicellulose) hydrolysis. This abundance of different activities complicates enzyme recycling since the individual enzymes behave differently in the process. Previously, the general perception was that β-glucosidases could easily be recycled via the liquid phase, as they have mostly been observed not to adsorb to pretreated biomass or only adsorb to a minor extent. Results The results from this study with Cellic® CTec2 revealed that the vast majority of the β-glucosidase activity was lost from the liquid phase and was adsorbed to the residual biomass during hydrolysis and fermentation. Adsorption studies with β-glucosidases in two commercial preparations (Novozym 188 and Cellic® CTec2) to substrates mimicking the components in pretreated wheat straw revealed that the Aspergillus niger β-glucosidase in Novozym 188 did not adsorb significantly to any of the components in pretreated wheat straw, whereas the β-glucosidase in Cellic® CTec2 adsorbed strongly to lignin. The extent of adsorption of β-glucosidase from Cellic® CTec2 was affected by both type of biomass and pretreatment method. With approximately 65% of the β-glucosidases from Cellic® CTec2 adsorbed onto lignin from pretreated wheat straw, the activity of the β-glucosidases in the slurry decreased by only 15%. This demonstrated that some enzyme remained active despite being bound. It was possible to reduce the adsorption of Cellic® CTec2 β-glucosidase to lignin from pretreated wheat straw by addition of bovine serum albumin or poly(ethylene glycol). Conclusions Contrary to the β-glucosidases in Novozym 188, the β-glucosidases in Cellic® CTec2 adsorb significantly to lignin. The lignin adsorption observed for Cellic® CTec2 is

Comparing the performance of Miscanthus x giganteus and wheat straw biomass in sulfuric acid based pretreatment.

PubMed

Kärcher, M A; Iqbal, Y; Lewandowski, I; Senn, T

2015-03-01

The objective of this study was to assess and compare the suitability of Miscanthus x giganteus and wheat straw biomass in dilute acid catalyzed pretreatment. Miscanthus and wheat straw were treated in a dilute sulfuric acid/steam explosion pretreatment. As a result of combining dilute sulfuric acid- and steam explosion pretreatment the hemicellulose hydrolysis yields (96% in wheat straw and 90% in miscanthus) in both substrates were higher than reported in literature. The combined severity factor (=CSF) for optimal hemicellulose hydrolysis was 1.9 and 1.5 in for miscanthus and wheat straw respectively. Because of the higher CSF value more furfural, furfuryl alcohol, 5-hydroxymethylfurfural and acetic acid was formed in miscanthus than in wheat straw pretreatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biorefining of wheat straw: accounting for the distribution of mineral elements in pretreated biomass by an extended pretreatment-severity equation.

PubMed

Le, Duy Michael; Sørensen, Hanne R; Knudsen, Niels Ole; Schjoerring, Jan K; Meyer, Anne S

2014-01-01

Mineral elements present in lignocellulosic biomass feedstocks may accumulate in biorefinery process streams and cause technological problems, or alternatively can be reaped for value addition. A better understanding of the distribution of minerals in biomass in response to pretreatment factors is therefore important in relation to development of new biorefinery processes. The objective of the present study was to examine the levels of mineral elements in pretreated wheat straw in response to systematic variations in the hydrothermal pretreatment parameters (pH, temperature, and treatment time), and to assess whether it is possible to model mineral levels in the pretreated fiber fraction. Principal component analysis of the wheat straw biomass constituents, including mineral elements, showed that the recovered levels of wheat straw constituents after different hydrothermal pretreatments could be divided into two groups: 1) Phosphorus, magnesium, potassium, manganese, zinc, and calcium correlated with xylose and arabinose (that is, hemicellulose), and levels of these constituents present in the fiber fraction after pretreatment varied depending on the pretreatment-severity; and 2) Silicon, iron, copper, aluminum correlated with lignin and cellulose levels, but the levels of these constituents showed no severity-dependent trends. For the first group, an expanded pretreatment-severity equation, containing a specific factor for each constituent, accounting for variability due to pretreatment pH, was developed. Using this equation, the mineral levels could be predicted with R(2) > 0.75; for some with R(2) up to 0.96. Pretreatment conditions, especially pH, significantly influenced the levels of phosphorus, magnesium, potassium, manganese, zinc, and calcium in the resulting fiber fractions. A new expanded pretreatment-severity equation is proposed to model and predict mineral composition in pretreated wheat straw biomass.

Potential of a gypsum-free composting process of wheat straw for mushroom production.

PubMed

Mouthier, Thibaut M B; Kilic, Baris; Vervoort, Pieter; Gruppen, Harry; Kabel, Mirjam A

2017-01-01

Wheat straw based composting generates a selective substrate for mushroom production. The first phase of this process requires 5 days, and a reduction in time is wished. Here, we aim at understanding the effect of gypsum on the duration of the first phase and the mechanism behind it. Hereto, the regular process with gypsum addition and the same process without gypsum were studied during a 5-day period. The compost quality was evaluated based on compost lignin composition analysed by py-GC/MS and its degradability by a commercial (hemi-)cellulolytic enzyme cocktail. The composting phase lead to the decrease of the pyrolysis products 4-vinylphenol and 4-vinylguaiacol that can be associated with p-coumarates and ferulates linking xylan and lignin. In the regular compost, the enzymatic conversion reached 32 and 39% for cellulose, and 23 and 32% for xylan after 3 and 5 days, respectively. In absence of gypsum similar values were reached after 2 and 4 days, respectively. Thus, our data show that in absence of gypsum the desired compost quality was reached 20% earlier compared to the control process.

Potential of pelleted wheat straw as an alternative bedding material for broilers.

PubMed

Kheravii, S K; Swick, R A; Choct, M; Wu, S-B

2017-06-01

Broiler chickens are commonly placed on wood shavings as litter, but alternative litter sources are required due to the scarcity of wood shavings in many parts of the world. This study aimed to compare pelleted straw, chopped wheat straw, wood shavings, rice hulls, and shredded paper as litter candidates. Three-hundred-sixty Ross 308 one-day-old male chicks were used in this study. There were 5 litter treatments with 6 replicate pens, each with 12 birds. The feed conversion ratio (FCR) of birds reared on pelleted straw was improved compared (P < 0.05) to that of birds raised on rice hulls, whereas it did not differ for birds placed on wood shavings, rice hulls, chopped straw, or shredded paper. It was observed that the birds reared on wood shavings had higher relative gizzard weight at d 24 compared to those reared on pelleted straw (P < 0.05). Gizzard pH and measured cecal bacterial groups were not affected by the type of bedding material. Cecal bacterial groups measured at d 10 were not affected by bedding material. Birds reared on pelleted wheat straw had a lower incidence of footpad lesions than those on chopped straw and shredded paper on d 24 (P < 0.001) and 29 (P < 0.01). Litter source did not affect the occurrence of breast blisters at d 24, 29, or 35. On d 24, 29, and 35, pelleted straw litter was less caked than chopped straw and shredded paper (P < 0.001) whereas no significant differences were observed among pelleted straw, wood shavings, and rice hulls. The study demonstrated the potential benefits to using pelleted wheat straw as a bedding material. Further assessment of pelleting of wheat straw and other materials on broiler health, performance, and welfare are needed to determine the economic benefits of pelleted litter. © 2017 Poultry Science Association Inc.

Two-Dimensional NMR Evidence for Cleavage of Lignin and Xylan Substituents in Wheat Straw Through Hydrothermal Pretreatment and Enzymatic Hydrolysis

Treesearch

Daniel J. Yelle; Prasad Kaparaju; Christopher G. Hunt; Kolby Hirth; Hoon Kim; John Ralph; Claus Felby

2012-01-01

Solution-state two-dimensional (2D) nuclear magnetic resonance (NMR) spectroscopy of plant cell walls is a powerful tool for characterizing changes in cell wall chemistry during the hydrothermal pretreatment process of wheat straw for second-generation bioethanol production. One-bond 13C-1H NMR correlation spectroscopy, via...

Lignin fate and characterization during ionic liquid biomass pretreatment for renewable chemicals and fuels production

USDA-ARS?s Scientific Manuscript database

The fate of lignin from wheat straw, Miscanthus, and Loblolly pine after pretreatment by a non-toxic and recyclable ionic liquid (IL), [C2mim][OAc], followed by enzymatic hydrolysis was investigated. The lignin partitioned into six process streams, each of which was quantified and analyzed by a comb...

Effect of pretreatment severity in continuous steam explosion on enzymatic conversion of wheat straw: Evidence from kinetic analysis of hydrolysis time courses.

PubMed

Monschein, Mareike; Nidetzky, Bernd

2016-01-01

Focusing on continuous steam explosion, the influence of pretreatment severity due to varied acid loading on hydrolysis of wheat straw by Trichoderma reesei cellulases was investigated based on kinetic evaluation of the saccharification of each pretreated substrate. Using semi-empirical descriptors of the hydrolysis time course, key characteristics of saccharification efficiency were captured in a quantifiable fashion. Not only hydrolysis rates per se, but also the transition point of their bi-phasic decline was crucial for high saccharification degree. After 48h the highest saccharification was achieved for substrate pretreated at relatively low severity (1.2% acid). Higher severity increased enzyme binding to wheat straw, but reduced the specific hydrolysis rates. Higher affinity of the lignocellulosic material for cellulases does not necessarily result in increased saccharification, probably because of lignin modifications occurring at high pretreatment severities. At comparable severity, continuous pretreatment produced a substrate more susceptible to enzymatic hydrolysis than the batch process. Copyright © 2015 Elsevier Ltd. All rights reserved.

Degradation of Lignin by Cyathus Species

PubMed Central

Abbott, Thomas P.; Wicklow, Donald T.

1984-01-01

The ability of 12 Cyathus species to degrade 14C-labeled lignin in kenaf was studied. The sum of 14C released into solution plus 14C released into the gas phase over a 32-day fermentation period was used to determine average daily rates of lignin biodegradation. Cyathus pallidus. C. africanus, and C. berkeleyanus delignified kenaf most rapidly. C. canna showed the greatest preference for lignin degradation over other plant components, and its rate of lignin degradation was only slightly lower than the three most active species. The apparent ability of fungi to metabolize low-molecular-weight lignin breakdown products correlated well with their overall delignification rates. C. stercoreus metabolized degradation products of lignin from wheat straw better than those from kenaf lignin, based on the amount of low-molecular-weight products left in solution. PMID:16346497

Scale-up of wheat straw conversion to fuel ethanol at 100 liter scale

USDA-ARS?s Scientific Manuscript database

Wheat straw can serve as low cost feedstock for conversion to ethanol. Pretreatment is crucial prior to enzymatic hydrolysis. We have used dilute H2SO4 pretreatment at a high temperature for pretreatment of wheat straw. The pretreated hydrolyzate was bioabated using a novel fungal strain able to ...

Improving enzymatic hydrolysis efficiency of wheat straw through sequential autohydrolysis and alkaline post-extraction.

PubMed

Wu, Xinxing; Huang, Chen; Zhai, Shengcheng; Liang, Chen; Huang, Caoxing; Lai, Chenhuan; Yong, Qiang

2018-03-01

In this work, a two-step pretreatment process of wheat straw was established by combining autohydrolysis pretreatment and alkaline post-extraction. The results showed that employing alkaline post-extraction to autohydrolyzed wheat straw could significantly improve its enzymatic hydrolysis efficiency from 36.0% to 83.7%. Alkaline post-extraction lead to the changes of the structure characteristics of autohydrolyzed wheat straw. Associations between enzymatic hydrolysis efficiency and structure characteristics were also studied. The results showed that the factors of structure characteristics such as delignification, xylan removal yield, crystallinity, accessibility and hydrophobicity are positively related to enzymatic hydrolysis efficiency within a certain range for alkaline post-extracted wheat straw. The results demonstrated that autohydrolysis coupled with alkaline post-extraction is an effective and promising method to gain fermentable sugars from biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of thermal pretreatment on chemical composition, physical structure and biogas production kinetics of wheat straw.

PubMed

Rajput, Asad Ayub; Zeshan; Visvanathan, Chettiyappan

2018-05-21

Hard lignocellulosic structure of wheat straw is the main hindrance in its anaerobic digestion. Thus, a laboratory scale batch experiment was conducted to study the effect of thermal pretreatment on anaerobic digestion of wheat straw. For this purpose, different thermal pretreatment temperatures of 120, 140, 160 and 180 °C were studied and the results were compared with raw wheat straw. Significant differences in biogas production were observed at temperature higher than 160 °C. Highest biogas yield of 615 Nml/gVS and volatile solids reduction of 69% was observed from wheat straw pretreated at 180 °C. Wheat straw pretreated at 180 °C showed 53% higher biogas yield as compared to untreated. Further, FTIR analysis revealed change in chemical bonds of lignocellulosic structure of wheat straw. Modified Gompertz model was best fitted on biogas production data and predicted shorter lag phase time and higher biogas production as the pretreatment temperature increased. Overall, change in lignocellulosic structure and increase in cellulose content were the main reason in enhancing biogas production. Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimizing Phosphoric Acid plus Hydrogen Peroxide (PHP) Pretreatment on Wheat Straw by Response Surface Method for Enzymatic Saccharification.

PubMed

Qiu, Jingwen; Wang, Qing; Shen, Fei; Yang, Gang; Zhang, Yanzong; Deng, Shihuai; Zhang, Jing; Zeng, Yongmei; Song, Chun

2017-03-01

Wheat straw was pretreated by phosphoric acid plus hydrogen peroxide (PHP), in which temperature, time, and H 3 PO 4 proportion for pretreatment were investigated by using response surface method. Results indicated that hemicellulose and lignin removal positively responded to the increase of pretreatment temperature, H 3 PO 4 proportion, and time. H 3 PO 4 proportion was the most important variable to control cellulose recovery, followed by pretreatment temperature and time. Moreover, these three variables all negatively related to cellulose recovery. Increasing H 3 PO 4 proportion can improve enzymatic hydrolysis; however, reduction on cellulose recovery results in decrease of glucose yield. Extra high temperature or long time for pretreatment was not beneficial to enzymatic hydrolysis and glucose yield. Based on the criterion for minimizing H 3 PO 4 usage and maximizing glucose yield, the optimized pretreatment conditions was 40 °C, 2.0 h, and H 3 PO 4 proportion of 70.2 % (H 2 O 2 proportion of 5.2 %), by which glucose yielded 299 mg/g wheat straw (946.2 mg/g cellulose) after 72-h enzymatic hydrolysis.

Effect of Pleurotus ostreatus and Erwinia carotovora on wheat straw digestibility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Streeter, C.L.; Conway, K.E.; Horn, G.W.

1981-11-01

The objectives of this study were to determine whether growing Pleurotus ostreatus and Erwinia carotovora on wheat straw would synergistically improve the digestibility of straw and whether there was a necessity of sterilizing the straw by autoclaving prior to inoculation. Dry matter decomposition of autoclaved and non-autoclaved straw was similar when both organisms were used in the system after 28 days incubation. However, in vitro ruminal dry matter digestibility of straw was significantly improved (P less than 10) only when the straw was autoclaved prior to inoculation with both organisms. (Refs. 21).

Effects of grinding processes on enzymatic degradation of wheat straw.

PubMed

Silva, Gabriela Ghizzi D; Couturier, Marie; Berrin, Jean-Guy; Buléon, Alain; Rouau, Xavier

2012-01-01

The effectiveness of wheat straw fine to ultra-fine grindings at pilot scale was studied. The produced powders were characterised by their particle-size distribution (laser diffraction), crystallinity (WAXS) and enzymatic degradability (Trichoderma reesei enzymatic cocktail). A large range of wheat-straw powders was produced: from coarse (median particle size ∼800 μm) to fine particles (∼50 μm) using sieve-based grindings, then ultra-fine particles ∼20 μm by jet milling and ∼10 μm by ball milling. The wheat straw degradability was enhanced by the decrease of particle size until a limit: ∼100 μm, up to 36% total carbohydrate and 40% glucose hydrolysis yields. Ball milling samples overcame this limit up to 46% total carbohydrate and 72% glucose yields as a consequence of cellulose crystallinity reduction (from 22% to 13%). Ball milling appeared to be an effective pretreatment with similar glucose yield and superior carbohydrate yield compared to steam explosion pretreatment. Copyright © 2011 Elsevier Ltd. All rights reserved.

Utilization of hydrothermally pretreated wheat straw for production of bioethanol and carotene-enriched biomass.

PubMed

Petrik, Siniša; Kádár, Zsófia; Márová, Ivana

2013-04-01

In this work hydrothermally pretreated wheat straw was used for production of bioethanol by Saccharomyces cerevisiae and carotene-enriched biomass by red yeasts Rhodotorula glutinis, Cystofilobasidium capitatum and Sporobolomyces roseus. To evaluate the convertibility of pretreated wheat straw into ethanol, simultaneous saccharification and fermentation of S. cerevisiae was performed under semi-anaerobic conditions. The highest ethanol production efficiency of 65-66% was obtained following pretreatment at 200°C without the catalytic action of acetic acid, and at 195 and 200°C respectively in the presence of catalyst. Red yeast strain S. roseus produced 1.73-2.22 mg g(-1) of ergosterol on the filter cake, 1.15-4.17 mg g(-1) of ergosterol and 1.23-1.56 mg g(-1) of β-carotene on pretreated wheat straw hydrolysates and also the highest amount of carotenoids and ergosterol on untreated wheat straw (1.70 and 4.17 mg g(-1), respectively). Copyright © 2013 Elsevier Ltd. All rights reserved.

Potential of a gypsum-free composting process of wheat straw for mushroom production

PubMed Central

Mouthier, Thibaut M. B.; Kilic, Baris; Vervoort, Pieter; Gruppen, Harry

2017-01-01

Wheat straw based composting generates a selective substrate for mushroom production. The first phase of this process requires 5 days, and a reduction in time is wished. Here, we aim at understanding the effect of gypsum on the duration of the first phase and the mechanism behind it. Hereto, the regular process with gypsum addition and the same process without gypsum were studied during a 5-day period. The compost quality was evaluated based on compost lignin composition analysed by py-GC/MS and its degradability by a commercial (hemi-)cellulolytic enzyme cocktail. The composting phase lead to the decrease of the pyrolysis products 4-vinylphenol and 4-vinylguaiacol that can be associated with p-coumarates and ferulates linking xylan and lignin. In the regular compost, the enzymatic conversion reached 32 and 39% for cellulose, and 23 and 32% for xylan after 3 and 5 days, respectively. In absence of gypsum similar values were reached after 2 and 4 days, respectively. Thus, our data show that in absence of gypsum the desired compost quality was reached 20% earlier compared to the control process. PMID:28982119

Xylanase and β-xylosidase production by Aspergillus ochraceus: new perspectives for the application of wheat straw autohydrolysis liquor.

PubMed

Michelin, Michele; Polizeli, Maria de Lourdes T M; Ruzene, Denise S; Silva, Daniel P; Vicente, António A; Jorge, João A; Terenzi, Héctor F; Teixeira, José A

2012-01-01

The xylanase biosynthesis is induced by its substrate-xylan. The high xylan content in some wastes such as wheat residues (wheat bran and wheat straw) makes them accessible and cheap sources of inducers to be mainly applied in great volumes of fermentation, such as those of industrial bioreactors. Thus, in this work, the main proposal was incorporated in the nutrient medium wheat straw particles decomposed to soluble compounds (liquor) through treatment of lignocellulosic materials in autohydrolysis process, as a strategy to increase and undervalue xylanase production by Aspergillus ochraceus. The wheat straw autohydrolysis liquor produced in several conditions was used as a sole carbon source or with wheat bran. The best conditions for xylanase and β-xylosidase production were observed when A. ochraceus was cultivated with 1% wheat bran added of 10% wheat straw liquor (produced after 15 min of hydrothermal treatment) as carbon source. This substrate was more favorable when compared with xylan, wheat bran, and wheat straw autohydrolysis liquor used separately. The application of this substrate mixture in a stirred tank bioreactor indicated the possibility of scaling up the process to commercial production.

Pulp properties resulting from different pretreatments of wheat straw and their influence on enzymatic hydrolysis rate.

PubMed

Rossberg, Christine; Steffien, Doreen; Bremer, Martina; Koenig, Swetlana; Carvalheiro, Florbela; Duarte, Luís C; Moniz, Patrícia; Hoernicke, Max; Bertau, Martin; Fischer, Steffen

2014-10-01

Wheat straw was subjected to three different processes prior to saccharification, namely alkaline pulping, natural pulping and autohydrolysis, in order to study their effect on the rate of enzymatic hydrolysis. Parameters like medium concentration, temperature and time have been varied in order to optimize each method. Milling the raw material to a length of 4mm beforehand showed the best cost-value-ratio compared to other grinding methods studied. Before saccharification the pulp can be stored in dried form, leading to a high yield of glucose. Furthermore the relation of pulp properties (i.e. intrinsic viscosity, Klason-lignin and hemicelluloses content, crystallinity, morphology) to cellulose hydrolysis is discussed. Copyright © 2014 Elsevier Ltd. All rights reserved.

Enhanced yields and soil quality in a wheat-maize rotation using buried straw mulch.

PubMed

Guo, Zhibin; Liu, Hui; Wan, Shuixia; Hua, Keke; Jiang, Chaoqiang; Wang, Daozhong; He, Chuanlong; Guo, Xisheng

2017-08-01

Straw return may improve soil quality and crop yields. In a 2-year field study, a straw return method (ditch-buried straw return, DB-SR) was used to investigate the soil quality and crop productivity effects on a wheat-corn rotation system. This study consisted of three treatments, each with three replicates: (1) mineral fertilisation alone (CK0); (2) mineral fertilisation + 7500 kg ha -1 wheat straw incorporated at depth of 0-15 cm (NPKWS); and (3) mineral fertilisation + 7500 kg ha -1 wheat straw ditch buried at 15-30 cm (NPKDW). NPKWS and NPKDW enhanced crop yield and improved soil biotical properties compared to mineral fertilisation alone. NPKDW contributed to greater crop yields and soil nutrient availability at 15-30 cm depths, compared to NPKWS treatment. NPKDW enhanced soil microbial activity and bacteria species richness and diversity in the 0-15 cm layer. NPKWS increased soil microbial biomass, bacteria species richness and diversity at 15-30 cm. The comparison of the CK0 and NPKWS treatments indicates that a straw ditch buried by digging to the depth of 15-30 cm can improve crop yields and soil quality in a wheat-maize rotation system. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Pyrolysis of agricultural biomass residues: Comparative study of corn cob, wheat straw, rice straw and rice husk.

PubMed

Biswas, Bijoy; Pandey, Nidhi; Bisht, Yashasvi; Singh, Rawel; Kumar, Jitendra; Bhaskar, Thallada

2017-08-01

Pyrolysis studies on conventional biomass were carried out in fixed bed reactor at different temperatures 300, 350, 400 and 450°C. Agricultural residues such as corn cob, wheat straw, rice straw and rice husk showed that the optimum temperatures for these residues are 450, 400, 400 and 450°C respectively. The maximum bio-oil yield in case of corn cob, wheat straw, rice straw and rice husk are 47.3, 36.7, 28.4 and 38.1wt% respectively. The effects of pyrolysis temperature and biomass type on the yield and composition of pyrolysis products were investigated. All bio-oils contents were mainly composed of oxygenated hydrocarbons. The higher area percentages of phenolic compounds were observed in the corn cob bio-oil than other bio-oils. From FT-IR and 1 H NMR spectra showed a high percentage of aliphatic functional groups for all bio-oils and distribution of products is different due to differences in the composition of agricultural biomass. Copyright © 2017 Elsevier Ltd. All rights reserved.

Phosphomolybdic acid and ferric iron as efficient electron mediators for coupling biomass pretreatment to produce bioethanol and electricity generation from wheat straw.

PubMed

Ding, Yi; Du, Bo; Zhao, Xuebing; Zhu, J Y; Liu, Dehua

2017-03-01

Phosphomolybdic acid (PMo 12 ) was used as an electron mediator and proton carrier to mediate biomass pretreatment for ethanol production and electricity generation from wheat straw. In the pretreatment, lignin was oxidized anaerobically by PMo 12 with solubilization of a fraction of hemicelluloses, and the PMo 12 was simultaneously reduced. In an external liquid flow cell, the reduced PMo 12 was re-oxidized with generation of electricity. The effects of several factors on pretreatment were investigated for optimizing the conditions. Enzymatic conversion of cellulose and xylan were about 80% and 45%, respectively, after pretreatment of wheat straw with 0.25M PMo 12 , at 95°C for 45min. FeCl 3 was found to be an effective liquid mediator to transfer electrons to air, the terminal electron acceptor. By investigating the effects of various operation parameters and cell structural factors, the highest output power density of about 11mW/cm 2 was obtained for discharging of the reduced PMo 12 . Copyright © 2017 Elsevier Ltd. All rights reserved.

Lignin fate and characterization during ionic liquid biomass pretreatment for renewable chemicals and fuels production

Treesearch

Noppadon Sathitsuksanoh; Kevin M. Holtman; Daniel J. Yelle; Trevor Morgan; Vitalie Stavila; Jeffrey Pelton; Harvey Blanch; Blake A. Simmons; Anthe George

2014-01-01

The fate of lignin from wheat straw, Miscanthus, and Loblolly pine after pretreatment by a non-toxic and recyclable ionic liquid (IL), [C2mim][OAc], followed by enzymatic hydrolysis was investigated. The lignin partitioned into six process streams, each of which was quantified and analyzed by a combination of a novel solution-state two-dimensional (2D) nuclear magnetic...

Properties of Wheat-Straw Boards with Frw Based on Interface Treatment

NASA Astrophysics Data System (ADS)

Zhu, X. D.; Wang, F. H.; Liu, Y.

This paper explored the effect of MDI, UF and FRW content on the mechanical and fire retardant property of straw based panels with surface alkali liquor processing. In order to manufacture the straw based panel with high quality, low toxic and fire retardant, the interface of wheat-straw was treated with alkaline liquid, and the orthogonal test was carried out to optimize the technical parameters. The conductivity and diffusion coefficient K of the straw material after alkaline liquid treatment increased obviously. This indicated that alkaline liquid treatment improved the surface wet ability of straw, which is helpful for the infiltration of resin. The results of orthogonal test showed that the optimized treating condition was alkaline liquid concentration as 0.4-0.8%, alkaline dosage as 1:2.5-1:4.5, alkalinetreated time as 12h-48 h.The physical and mechanical properties of wheat-straw boards after treated increased remarkably and it could satisfy the national standard. The improvement of the straw surface wet ability is helpful to the forming of chemical bond. Whereas the variance analysis of the fire retardant property of straw based panel showed that TTI, pkHRR and peak value appearance time were not affected by the MDI, UF and FRW content significantly. The results of orthogonal test showed that the optimized processing condition was MDI content as 3%, UF resin content as 6% and the FRW content as 10%.

One step conversion of wheat straw to sugars by simultaneous ball milling, mild acid, and fungus Penicillium simplicissimum treatment.

PubMed

Yuan, Li; Chen, Zhenhua; Zhu, Yonghua; Liu, Xuanming; Liao, Hongdong; Chen, Ding

2012-05-01

Wheat straw is one of the major lignocellulosic plant residues in many countries including China. An attractive alternative is the utilization of wheat straw for bioethanol production. This article mainly studies a simple one-step wet milling with Penicillium simplicissimum and weak acid to hydrolysis of wheat straw. The optimal condition for hydrolysis was ball milling 48 h in citrate solvent (pH = 4) with P. simplicissimum H5 at the speed of 500 rpm and the yield of sugar increased with increased milling time. Corresponding structure transformations before and after milling analyzed by X-ray diffraction, transmission Fourier transform infrared spectroscopy, and environmental scanning electron microscopy clearly indicated that this combined treatment could be attributed to the crystalline and chemical structure changes of cellulose in wheat straw during ball milling. This combined treatment of ball milling, mild acid, and fungus hydrolysis enabled the conversion of the wheat straw. Compared with traditional method of ball milling, this work showed a more simple, novel, and environmentally friendly way in mechanochemical treatment of wheat straw.

[Effects of nitrogen application rates and straw returning on nutrient balance and grain yield of late sowing wheat in rice-wheat rotation].

PubMed

Zhang, Shan; Shi, Zu-liang; Yang, Si-jun; Gu, Ke-jun; Dai, Ting-bo; Wang, Fei; Li, Xiang; Sun, Ren-hua

2015-09-01

Field experiments were conducted to study the effects of nitrogen application rates and straw returning on grain yield, nutrient accumulation, nutrient release from straw and nutrient balance in late sowing wheat. The results showed that straw returning together with appropriate application of nitrogen fertilizer improved the grain yield. Dry matter, nitrogen, phosphorus and potassium accumulation increased significantly as the nitrogen application rate increased. At the same nitrogen application rate (270 kg N · hm(-2)), the dry matter, phosphorus and potassium accumulation of the treatment with straw returning were higher than that without straw returning, but the nitrogen accumulation was lower. Higher-rate nitrogen application promoted straw decomposition and nutrient release, and decreased the proportion of the nutrient released from straw after jointing. The dry matter, phosphorus and potassium release from straw showed a reverse 'N' type change with the wheat growing, while nitrogen release showed a 'V' type change. The nutrient surplus increased significantly with the nitrogen application rate. At the nitrogen application rate for the highest grain yield, nitrogen and potassium were surplus significantly, and phosphorus input could keep balance. It could be concluded that as to late sowing wheat with straw returning, applying nitrogen at 257 kg · hm(-2) and reducing potassium fertilizer application could improve grain yield and reduce nutrients loss.

Production of ethyl levulinate by direct conversion of wheat straw in ethanol media.

PubMed

Chang, Chun; Xu, Guizhuan; Jiang, Xiaoxian

2012-10-01

The production of ethyl levulinate from wheat straw by direct conversion in ethanol media was investigated. Response surface methodology (RSM) was applied to optimize the effects of processing parameters, and the regression analysis was performed on the data obtained. A close agreement between the experimental results and the model predictions was achieved. The optimal conditions for ethyl levulinate production from wheat straw were acid concentration 2.5%, reaction temperature 183°C, mass ratio of liquid to solid 19.8 and reaction time 36 min. Under the optimum conditions, the yield of ethyl levulinate 17.91% was obtained, representing a theoretical yield of 51.0%. The results suggest that wheat straw can be used as potential raw materials for the production of ethyl levulinate by direct conversion in ethanol media. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bulk density and compaction behavior of knife mill chopped switchgrass,wheat straw, and corn stover

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chevanan, Nehru; Womac, A.R.; Bitra, V.S.P.

2009-08-01

Bulk density of comminuted biomass significantly increased by vibration during handling and transportation, and by normal pressure during storage. Compaction characteristics affecting the bulk density of switchgrass, wheat straw, and corn stover chopped in a knife mill at different operating conditions and using four different classifying screens were studied. Mean loose-filled bulk densities were 67.5 18.4 kg/m3 for switchgrass, 36.1 8.6 kg/m3 for wheat straw, and 52.1 10.8 kg/m3 for corn stover. Mean tapped bulk densities were 81.8 26.2 kg/m3 for switchgrass, 42.8 11.7 kg/m3 for wheat straw, and 58.9 13.4 kg/m3 for corn stover. Percentage changes in compressibility duemore » to variation in particle size obtained from a knife mill ranged from 64.3 to 173.6 for chopped switchgrass, 22.2 51.5 for chopped wheat straw and 42.1 117.7 for chopped corn stover within the tested consolidation pressure range of 5 120 kPa. Pressure and volume relationship of chopped biomass during compression with application of normal pressure can be characterized by the Walker model and Kawakita and Ludde model. Parameter of Walker model was correlated to the compressibility with Pearson correlation coefficient greater than 0.9. Relationship between volume reduction in chopped biomass with respect to number of tappings studied using Sone s model indicated that infinite compressibility was highest for chopped switchgrass followed by chopped wheat straw and corn stover. Degree of difficulty in packing measured using the parameters of Sone s model indicated that the chopped wheat straw particles compacted very rapidly by tapping compared to chopped switchgrass and corn stover. These results are very useful for solving obstacles in handling bulk biomass supply logistics issues for a biorefinery.« less

Bulk density and compaction behavior of knife mill chopped switchgrass, wheat straw, and corn stover.

PubMed

Chevanan, Nehru; Womac, Alvin R; Bitra, Venkata S P; Igathinathane, C; Yang, Yuechuan T; Miu, Petre I; Sokhansanj, Shahab

2010-01-01

Bulk density of comminuted biomass significantly increased by vibration during handling and transportation, and by normal pressure during storage. Compaction characteristics affecting the bulk density of switchgrass, wheat straw, and corn stover chopped in a knife mill at different operating conditions and using four different classifying screens were studied. Mean loose-filled bulk densities were 67.5+/-18.4 kg/m(3) for switchgrass, 36.1+/-8.6 kg/m(3) for wheat straw, and 52.1+/-10.8 kg/m(3) for corn stover. Mean tapped bulk densities were 81.8+/-26.2 kg/m(3) for switchgrass, 42.8+/-11.7 kg/m(3) for wheat straw, and 58.9+/-13.4 kg/m(3) for corn stover. Percentage changes in compressibility due to variation in particle size obtained from a knife mill ranged from 64.3 to 173.6 for chopped switchgrass, 22.2-51.5 for chopped wheat straw and 42.1-117.7 for chopped corn stover within the tested consolidation pressure range of 5-120 kPa. Pressure and volume relationship of chopped biomass during compression with application of normal pressure can be characterized by the Walker model and Kawakita and Ludde model. Parameter of Walker model was correlated to the compressibility with Pearson correlation coefficient greater than 0.9. Relationship between volume reduction in chopped biomass with respect to number of tappings studied using Sone's model indicated that infinite compressibility was highest for chopped switchgrass followed by chopped wheat straw and corn stover. Degree of difficulty in packing measured using the parameters of Sone's model indicated that the chopped wheat straw particles compacted very rapidly by tapping compared to chopped switchgrass and corn stover. These results are very useful for solving obstacles in handling bulk biomass supply logistics issues for a biorefinery.

Anaerobic co-digestion of microalgal biomass and wheat straw with and without thermo-alkaline pretreatment.

PubMed

Solé-Bundó, Maria; Eskicioglu, Cigdem; Garfí, Marianna; Carrère, Hélène; Ferrer, Ivet

2017-08-01

This study aimed at analyzing the anaerobic co-digestion of microalgal biomass grown in wastewater and wheat straw. To this end, Biochemical Methane Potential (BMP) tests were carried out testing different substrate proportions (20-80, 50-50 and 80-20%, on a volatile solid basis). In order to improve their biodegradability, the co-digestion of both substrates was also evaluated after applying a thermo-alkaline pretreatment (10% CaO at 75°C for 24h). The highest synergies in degradation rates were observed by adding at least 50% of wheat straw. Therefore, the co-digestion of 50% microalgae - 50% wheat straw was investigated in mesophilic lab-scale reactors. The results showed that the methane yield was increased by 77% with the co-digestion as compared to microalgae mono-digestion, while the pretreatment only increased the methane yield by 15% compared to the untreated mixture. Thus, the anaerobic co-digestion of microalgae and wheat straw was successful even without applying a thermo-alkaline pretreatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of variety, cropping year, location and fertilizer application on nutritive value of durum wheat straw.

PubMed

Tolera, A; Tsegaye, B; Berg, T

2008-04-01

This study was carried out to assess the effects of variety, year, location and level of fertilizer application on chemical composition and in sacco dry matter (DM) degradability of durum wheat straw as well as to understand the relationship between straw quality and agronomic traits of the crop and to assess the possibilities of selecting wheat varieties that combine high grain yield with desirable straw quality. Two local (Arendeto and Tikur sinde) and two improved (Boohai and Gerardo) varieties of durum wheat (Triticum turgidum Desf.) were used in the experiment. The four varieties were grown at two locations (Akaki and Ejere) in the years 2001/2002 and 2002/2003 in 5 x 5 m plots in three replications. Diammonium phosphate and urea fertilizers were applied at four levels (0/0, 32/23, 41/23 and 64/46 kg/ha of nitrogen/phosphorus). Straw quality was assessed based on chemical composition and in sacco DM degradability. Correlation of straw quality with grain and straw yield and with other agronomic characteristics of the crop was determined. The potential utility index (a measure that integrates grain and digestible straw yield) was used for ranking of the varieties. The local varieties had higher crude protein (CP) and lower neutral detergent fibre contents and higher digestibility than the improved varieties. The cropping year and location had significant effect on CP content and degradability of the straw, which could be due to climatic variation. However, the fertilizer level did not have any significant effect on straw quality except that the CP content of the straw tended to increase with increasing level of fertilizer application. Based on the potential utility index the varieties ranked, in a decreasing order, as Tikur sinde > Arendeto > Gerardo > Boohai and the ranking was consistent across years and locations. Except the CP content, straw quality was not negatively correlated with grain and straw yield. This indicates that there is a possibility of

Selenium uptake by edible oyster mushrooms (Pleurotus sp.) from selenium-hyperaccumulated wheat straw.

PubMed

Bhatia, Poonam; Prakash, Ranjana; Prakash, N Tejo

2013-01-01

In an effort to produce selenium (Se)-fortifying edible mushrooms, five species of oyster mushroom (Pleurotus sp.), were cultivated on Se-rich wheat straw collected from a seleniferous belt of Punjab, India. Total selenium was analyzed in the selenium hyperaccumulated wheat straw and the fruiting bodies. Significantly high levels (p<0.0001) of Se uptake were observed in fruiting bodies of all mushrooms grown on Se-rich wheat straw. To the best of our knowledge, accumulation and quantification of selenium in mushrooms has hitherto not been reported with substrates naturally enriched with selenium. The results demonstrate the potential of selenium-rich agricultural residues as substrates for production of Se-enriched mushrooms and the ability of different species of oyster mushrooms to absorb and fortify selenium. The study envisages potential use of selenium-rich agricultural residues towards cultivation of Se-enriched mushrooms for application in selenium supplementation or neutraceutical preparations.

Effects of Different Tillage and Straw Return on Soil Organic Carbon in a Rice-Wheat Rotation System

PubMed Central

Zhu, Liqun; Hu, Naijuan; Yang, Minfang; Zhan, Xinhua; Zhang, Zhengwen

2014-01-01

Soil management practices, such as tillage method or straw return, could alter soil organic carbon (C) contents. However, the effects of tillage method or straw return on soil organic C (SOC) have showed inconsistent results in different soil/climate/cropping systems. The Yangtze River Delta of China is the main production region of rice and wheat, and rice-wheat rotation is the most important cropping system in this region. However, few studies in this region have been conducted to assess the effects of different tillage methods combined with straw return on soil labile C fractions in the rice-wheat rotation system. In this study, a field experiment was used to evaluate the effects of different tillage methods, straw return and their interaction on soil total organic C (TOC) and labile organic C fractions at three soil depths (0–7, 7–14 and 14–21 cm) for a rice-wheat rotation in Yangzhong of the Yangtze River Delta of China. Soil TOC, easily oxidizable C (EOC), dissolved organic C (DOC) and microbial biomass C (MBC) contents were measured in this study. Soil TOC and labile organic C fractions contents were significantly affected by straw returns, and were higher under straw return treatments than non-straw return at three depths. At 0–7 cm depth, soil MBC was significantly higher under plowing tillage than rotary tillage, but EOC was just opposite. Rotary tillage had significantly higher soil TOC than plowing tillage at 7–14 cm depth. However, at 14–21 cm depth, TOC, DOC and MBC were significantly higher under plowing tillage than rotary tillage except for EOC. Consequently, under short-term condition, rice and wheat straw both return in rice-wheat rotation system could increase SOC content and improve soil quality in the Yangtze River Delta. PMID:24586434

Yield and size of oyster mushroom grown on rice/wheat straw basal substrate supplemented with cotton seed hull.

PubMed

Yang, Wenjie; Guo, Fengling; Wan, Zhengjie

2013-10-01

Oyster mushroom (Pleurotus ostreatus) was cultivated on rice straw basal substrate, wheat straw basal substrate, cotton seed hull basal substrate, and wheat straw or rice straw supplemented with different proportions (15%, 30%, and 45% in rice straw substrate, 20%, 30%, and 40% in wheat straw substrate) of cotton seed hull to find a cost effective substrate. The effect of autoclaved sterilized and non-sterilized substrate on growth and yield of oyster mushroom was also examined. Results indicated that for both sterilized substrate and non-sterilized substrate, oyster mushroom on rice straw and wheat basal substrate have faster mycelial growth rate, comparatively poor surface mycelial density, shorter total colonization period and days from bag opening to primordia formation, lower yield and biological efficiency, lower mushroom weight, longer stipe length and smaller cap diameter than that on cotton seed hull basal substrate. The addition of cotton seed hull to rice straw and wheat straw substrate slowed spawn running, primordial development and fruit body formation. However, increasing the amount of cotton seed hull can increase the uniformity and white of mycelium, yield and biological efficiency, and increase mushroom weight, enlarge cap diameter and shorten stipe length. Compared to the sterilized substrate, the non-sterilized substrate had comparatively higher mycelial growth rate, shorter total colonization period and days from bag opening to primordia formation. However, the non-sterilized substrate did not gave significantly higher mushroom yield and biological efficiency than the sterilized substrate, but some undesirable characteristics, i.e. smaller mushroom cap diameter and relatively long stipe length.

Influence of straw incorporation with and without straw decomposer on soil bacterial community structure and function in a rice-wheat cropping system.

PubMed

Zhao, Jun; Ni, Tian; Xun, Weibing; Huang, Xiaolei; Huang, Qiwei; Ran, Wei; Shen, Biao; Zhang, Ruifu; Shen, Qirong

2017-06-01

To study the influence of straw incorporation with and without straw decomposer on bacterial community structure and biological traits, a 3-year field experiments, including four treatments: control without fertilizer (CK), chemical fertilizer (NPK), chemical fertilizer plus 7500 kg ha -1 straw incorporation (NPKS), and chemical fertilizer plus 7500 kg ha -1 straw incorporation and 300 kg ha -1 straw decomposer (NPKSD), were performed in a rice-wheat cropping system in Changshu (CS) and Jintan (JT) city, respectively. Soil samples were taken right after wheat (June) and rice (October) harvest in both sites, respectively. The NPKS and NPKSD treatments consistently increased crop yields, cellulase activity, and bacterial abundance in both sampling times and sites. Moreover, the NPKS and NPKSD treatments altered soil bacterial community structure, particularly in the wheat harvest soils in both sites, separating from the CK and NPK treatments. In the rice harvest soils, both NPKS and NPKSD treatments had no considerable impacts on bacterial communities in CS, whereas the NPKSD treatment significantly shaped bacterial communities compared to the other treatments in JT. These practices also significantly shifted the bacterial composition of unique operational taxonomic units (OTUs) rather than shared OTUs. The relative abundances of copiotrophic bacteria (Proteobacteria, Betaproteobacteria, and Actinobacteria) were positively correlated with soil total N, available N, and available P. Taken together, these results indicate that application of straw incorporation with and without straw decomposer could particularly stimulate the copiotrophic bacteria, enhance the soil biological activity, and thus, contribute to the soil productivity and sustainability in agro-ecosystems.

Enzymatic hydrolysis of autohydrolyzed wheat straw followed by refining to produce fermentable sugars.

PubMed

Ertas, Murat; Han, Qiang; Jameel, Hasan; Chang, Hou-min

2014-01-01

Wheat straw was pretreated using an autohydrolysis process with different temperatures (160-200 °C) and times (10-20 min) in order to allow the recovery of hemicellulose in the filtrate and help open up the structure of the biomass for improved accessibility of enzymes during enzymatic hydrolysis. Autohydrolysis at 190 °C for 10 min provided the highest overall sugar (12.2/100g raw wheat straw) in the autohydrolysis filtrate and recovered 62.3% of solid residue. Before enzymatic hydrolysis, the pulps obtained from each pretreatment condition were subjected to a refining post-treatment to improve enzyme accessibility. Enzymatic hydrolysis was performed for all the pretreated solids with and without refining post-treatment at the enzyme loadings of 4 and 10 FPU/g oven dry substrate for 96 h. A total of 30.4 g sugars can be recovered from 100g wheat straw at 180 °C for 20 min with 4 FPU/g enzyme charge. Copyright © 2013 Elsevier Ltd. All rights reserved.

Technoeconomic analysis of wheat straw densification in the Canadian Prairie Province of Manitoba.

PubMed

Mupondwa, Edmund; Li, Xue; Tabil, Lope; Phani, Adapa; Sokhansanj, Shahab; Stumborg, Mark; Gruber, Margie; Laberge, Serge

2012-04-01

This study presents a technoeconomic analysis of wheat straw densification in Canada's prairie province of Manitoba as an integral part of biomass-to-cellulosic-ethanol infrastructure. Costs of wheat straw bale and pellet transportation and densification are analysed, including densification plant profitability. Wheat straw collection radius increases nonlinearly with pellet plant capacity, from 9.2 to 37km for a 2-35tonnesh(-1) plant. Bales are cheaper under 250km, beyond which the cheapest feedstocks are pellets from the largest pellet plant that can be built to exploit economies of scale. Feedstocks account for the largest percentage of variable costs. Marginal and average cost curves suggest Manitoba could support a pellet plant up to 35tonnesh(-1). Operating below capacity (75-50%) significantly erodes a plant's net present value (NPV). Smaller plants require higher NPV break-even prices. Very large plants have considerable risk under low pellet prices and increased processing costs. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Fermentation technologies for ethanol production from wheat straw by a recombinant bacterium

USDA-ARS?s Scientific Manuscript database

Wheat straw, a globally abundant byproduct of wheat production, contains about 70% carbohydrate that could potentially be used as a low cost feedstock for production of fuel ethanol. Typically four process steps are involved in the production of ethanol from any lignocellulosic feedstock – pretreat...

Succinic acid production from orange peel and wheat straw by batch fermentations of Fibrobacter succinogenes S85.

PubMed

Li, Qiang; Siles, Jose A; Thompson, Ian P

2010-10-01

Succinic acid is a platform molecule that has recently generated considerable interests. Production of succinate from waste orange peel and wheat straw by consolidated bioprocessing that combines cellulose hydrolysis and sugar fermentation, using a cellulolytic bacterium, Fibrobacter succinogenes S85, was studied. Orange peel contains D-limonene, which is a well-known antibacterial agent. Its effects on batch cultures of F. succinogenes S85 were examined. The minimal concentrations of limonene found to inhibit succinate and acetate generation and bacterial growth were 0.01%, 0.1%, and 0.06% (v/v), respectively. Both pre-treated orange peel by steam distillation to remove D: -limonene and intact wheat straw were used as feedstocks. Increasing the substrate concentrations of both feedstocks, from 5 to 60 g/L, elevated succinate concentration and productivity but lowered the yield. In addition, pre-treated orange peel generated greater succinate productivities than wheat straw but had similar resultant titres. The greatest succinate titres were 1.9 and 2.0 g/L for pre-treated orange peel and wheat straw, respectively. This work demonstrated that agricultural waste such as wheat straw and orange peel can be biotransformed to succinic acid by a one-step consolidated bioprocessing. Measures to increase fermentation efficiency are also discussed.

Effect of wheat and Miscanthus straw biochars on soil enzymatic activity, ecotoxicity, and plant yield

NASA Astrophysics Data System (ADS)

Mierzwa-Hersztek, Monika; Gondek, Krzysztof; Klimkowicz-Pawlas, Agnieszka; Baran, Agnieszka

2017-07-01

The variety of technological conditions and raw materials from which biochar is produced is the reason why its soil application may have different effects on soil properties and plant growth. The aim of this study was to evaluate the effect of the addition of wheat straw and Miscanthus giganteus straw (5 t DM ha-1) and biochar obtained from this materials in doses of 2.25 and 5 t DM ha-1 on soil enzymatic activity, soil ecotoxicity, and plant yield (perennial grass mixture with red clover). The research was carried out under field conditions on soil with the granulometric composition of loamy sand. No significant effect of biochar amendment on soil enzymatic activity was observed. The biochar-amended soil was toxic to Vibrio fischeri and exhibited low toxicity to Heterocypris incongruens. Application of wheat straw biochar and M. giganteus straw biochar in a dose of 5 t DM ha-1 contributed to an increase in plant biomass production by 2 and 14%, respectively, compared to the soil with mineral fertilisation. Biochars had a more adverse effect on soil enzymatic activity and soil ecotoxicity to H. incongruens and V. fischeri than non-converted wheat straw and M. giganteus straw, but significantly increased the grass crop yield.

Impact of lignins isolated from pretreated lignocelluloses on enzymatic cellulose saccharification.

PubMed

Barsberg, Søren; Selig, Michael Joseph; Felby, Claus

2013-02-01

Lignins were enzymatically isolated from corn stover and wheat straw samples and subjected to hydrothermal or wet oxidation pretreatments for enzyme adsorption experimentations. Lignin contents of the isolates ranged from 26 to 71 % (w/w); cellulose ranged from 3 to 22 % (w/w); xylan from 0.7 to 6 % (w/w) and ash was from 5.8 to 30 % (w/w). ATR-IR analyses indicated significant and similar levels of calcium in all lignin isolates. Commercial cellulase adsorption studies showed that the presence of these lignins had no significant impact on the total amount of adsorbed enzyme in cellulose and cellulose-lignin systems. Consequently, the presence of the lignins had minimal effect, if any, on enzymatic cellulose conversion. Furthermore, this result, coupled with significant calcium levels in the isolated lignins, supports previous work suggesting lignin-calcium complexes reduce enzyme-lignin interactions.

Development and validation of a sensitive UPLC-MS/MS instrumentation and alkaline nitrobenzene oxidation method for the determination of lignin monomers in wheat straw.

PubMed

Zheng, Mengjing; Gu, Shubo; Chen, Jin; Luo, Yongli; Li, Wenqian; Ni, Jun; Li, Yong; Wang, Zhenlin

2017-06-15

A method to determine the lignin monomers (p-hydroxybenzaldehyde, vanillin and syringaldehyde) in plant cell wall of wheat internode was developed and validated using a high-throughput nitrobenzene oxidation step and ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) for quantification. UPLC analyses were carried out using an reversed phase C 18 column (ACQUITY UPLC BEH, 1.7μm, 2.1×100mm) and gradient elution with water and acetonitrile. This method was completely validated in terms of analyzing speed, linearity, sensitivity, limits of detection (LODs) and limits of quantification (LOQs).The three lignin monomers were successfully separated within 6min and only 2min were required to regain its equilibrium. The method linearity with regression coefficients values (R2) greater than 0.997. Additionally, LODs ranged from 0.21 to 0.89μgL -1 and LOQs ranged from 0.69 to 2.95μgL -1 . The applicability of this analytical approach for determining the three lignin monomers was confirmed by the successful analysis of real samples of wheat stem internodes. The nitrobenzene oxidation method was used for the analysis of lignin monomers. We have optimized the treatment temperature (170°C, 1h) and realized the high-throughput using the microwave digestion instrument. Recovery of this extraction method ranged from 68.4% to 77.7%. The analysis result showed that the guaiacyl unit (G) was the major component of lignin and there was a higher content of the syringyl unit (S) than that of the hydroxybenzyl unit (H). Copyright © 2017. Published by Elsevier B.V.

Direct measures of mechanical energy for knife mill size reduction of switchgrass, wheat straw, and corn stover.

PubMed

Bitra, Venkata S P; Womac, Alvin R; Igathinathane, C; Miu, Petre I; Yang, Yuechuan T; Smith, David R; Chevanan, Nehru; Sokhansanj, Shahab

2009-12-01

Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be +/-0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These

Mass loss and chemical structures of wheat and maize straws in response to ultraviolet-B radiation and soil contact.

PubMed

Zhou, Guixiang; Zhang, Jiabao; Mao, Jingdong; Zhang, Congzhi; Chen, Lin; Xin, Xiuli; Zhao, Bingzi

2015-10-01

The role of photodegradation, an abiotic process, has been largely overlooked during straw decomposition in mesic ecosystems. We investigated the mass loss and chemical structures of straw decomposition in response to elevated UV-B radiation with or without soil contact over a 12-month litterbag experiment. Wheat and maize straw samples with and without soil contact were exposed to three radiation levels: a no-sunlight control, ambient solar UV-B, and artificially elevated UV-B radiation. A block control with soil contact was not included. Compared with the no-sunlight control, UV-B radiation increased the mass loss by 14-19% and the ambient radiation by 9-16% for wheat and maize straws without soil contact after 12 months. Elevated UV-B exposure decreased the decomposition rates of both wheat and maize straws when in contact with soil. Light exposure resulted in decreased O-alkyl carbons and increased alkyl carbons for both the wheat and maize straws compared with no-sunlight control. The difference in soil contact may influence the contribution of photodegradation to the overall straw decomposition process. These results indicate that we must take into account the effects of photodegradation when explaining the mechanisms of straw decomposition in mesic ecosystems.

Mass loss and chemical structures of wheat and maize straws in response to ultraviolet-B radiation and soil contact

PubMed Central

Zhou, Guixiang; Zhang, Jiabao; Mao, Jingdong; Zhang, Congzhi; Chen, Lin; Xin, Xiuli; Zhao, Bingzi

2015-01-01

The role of photodegradation, an abiotic process, has been largely overlooked during straw decomposition in mesic ecosystems. We investigated the mass loss and chemical structures of straw decomposition in response to elevated UV-B radiation with or without soil contact over a 12-month litterbag experiment. Wheat and maize straw samples with and without soil contact were exposed to three radiation levels: a no-sunlight control, ambient solar UV-B, and artificially elevated UV-B radiation. A block control with soil contact was not included. Compared with the no-sunlight control, UV-B radiation increased the mass loss by 14–19% and the ambient radiation by 9–16% for wheat and maize straws without soil contact after 12 months. Elevated UV-B exposure decreased the decomposition rates of both wheat and maize straws when in contact with soil. Light exposure resulted in decreased O-alkyl carbons and increased alkyl carbons for both the wheat and maize straws compared with no-sunlight control. The difference in soil contact may influence the contribution of photodegradation to the overall straw decomposition process. These results indicate that we must take into account the effects of photodegradation when explaining the mechanisms of straw decomposition in mesic ecosystems. PMID:26423726

Production of bioethanol and value added compounds from wheat straw through combined alkaline/alkaline-peroxide pretreatment.

PubMed

Yuan, Zhaoyang; Wen, Yangbing; Li, Guodong

2018-07-01

An efficient scheme was developed for the conversion of wheat straw (WS) into bioethanol, silica and lignin. WS was pre-extracted with 0.2 mol/L sodium hydroxide at 30 °C for 5 h to remove about 91% of initial silica. Subsequently, the alkaline-pretreated solids were subjected to alkaline hydrogen peroxide (AHP) pretreatment with 40 mg hydrogen peroxide (H 2 O 2 )/g biomass at 50 °C for 7 h to prepare highly digestible substrate. The results of enzymatic hydrolysis demonstrated that the sequential alkaline-AHP pretreated WS was efficiently hydrolyzed at 10% (w/v) solids loading using an enzyme dosage of 10 mg protein/g glucan. The total sugar conversion of 92.4% was achieved. Simultaneous saccharification and co-fermentation (SSCF) was applied to produce ethanol from the two-stage pretreated substrate using Saccharomyces cerevisiae SR8u strain. Ethanol with concentration of 31.1 g/L was produced. Through the proposed process, about 86.4% and 54.1% of the initial silica and lignin were recovered, respectively. Copyright © 2018 Elsevier Ltd. All rights reserved.

Integrated Process for Ethanol, Biogas, and Edible Filamentous Fungi-Based Animal Feed Production from Dilute Phosphoric Acid-Pretreated Wheat Straw.

PubMed

Nair, Ramkumar B; Kabir, Maryam M; Lennartsson, Patrik R; Taherzadeh, Mohammad J; Horváth, Ilona Sárvári

2018-01-01

Integration of wheat straw for a biorefinery-based energy generation process by producing ethanol and biogas together with the production of high-protein fungal biomass (suitable for feed application) was the main focus of the present study. An edible ascomycete fungal strain Neurospora intermedia was used for the ethanol fermentation and subsequent biomass production from dilute phosphoric acid (0.7 to 1.2% w/v) pretreated wheat straw. At optimum pretreatment conditions, an ethanol yield of 84 to 90% of the theoretical maximum, based on glucan content of substrate straw, was observed from fungal fermentation post the enzymatic hydrolysis process. The biogas production from the pretreated straw slurry showed an improved methane yield potential up to 162% increase, as compared to that of the untreated straw. Additional biogas production, using the syrup, a waste stream obtained post the ethanol fermentation, resulted in a combined total energy output of 15.8 MJ/kg wheat straw. Moreover, using thin stillage (a waste stream from the first-generation wheat-based ethanol process) as a co-substrate to the biogas process resulted in an additional increase by about 14 to 27% in the total energy output as compared to using only wheat straw-based substrates. ᅟ.

Efficient anaerobic transformation of raw wheat straw by a robust cow rumen-derived microbial consortium.

PubMed

Lazuka, Adèle; Auer, Lucas; Bozonnet, Sophie; Morgavi, Diego P; O'Donohue, Michael; Hernandez-Raquet, Guillermina

2015-11-01

A rumen-derived microbial consortium was enriched on raw wheat straw as sole carbon source in a sequential batch-reactor (SBR) process under strict mesophilic anaerobic conditions. After five cycles of enrichment the procedure enabled to select a stable and efficient lignocellulolytic microbial consortium, mainly constituted by members of Firmicutes and Bacteroidetes phyla. The enriched community, designed rumen-wheat straw-derived consortium (RWS) efficiently hydrolyzed lignocellulosic biomass, degrading 55.5% w/w of raw wheat straw over 15days at 35°C and accumulating carboxylates as main products. Cellulolytic and hemicellulolytic activities, mainly detected on the cell bound fraction, were produced in the earlier steps of degradation, their production being correlated with the maximal lignocellulose degradation rates. Overall, these results demonstrate the potential of RWS to convert unpretreated lignocellulosic substrates into useful chemicals. Copyright © 2015 Elsevier Ltd. All rights reserved.

Long-term straw decomposition in agro-ecosystems described by a unified three-exponentiation equation with thermal time.

PubMed

Cai, Andong; Liang, Guopeng; Zhang, Xubo; Zhang, Wenju; Li, Ling; Rui, Yichao; Xu, Minggang; Luo, Yiqi

2018-05-01

Understanding drivers of straw decomposition is essential for adopting appropriate management practice to improve soil fertility and promote carbon (C) sequestration in agricultural systems. However, predicting straw decomposition and characteristics is difficult because of the interactions between many factors related to straw properties, soil properties, and climate, especially under future climate change conditions. This study investigated the driving factors of straw decomposition of six types of crop straw including wheat, maize, rice, soybean, rape, and other straw by synthesizing 1642 paired data from 98 published papers at spatial and temporal scales across China. All the data derived from the field experiments using little bags over twelve years. Overall, despite large differences in climatic and soil properties, the remaining straw carbon (C, %) could be accurately represented by a three-exponent equation with thermal time (accumulative temperature). The lignin/nitrogen and lignin/phosphorus ratios of straw can be used to define the size of labile, intermediate, and recalcitrant C pool. The remaining C for an individual type of straw in the mild-temperature zone was higher than that in the warm-temperature and subtropical zone within one calendar year. The remaining straw C after one thermal year was 40.28%, 37.97%, 37.77%, 34.71%, 30.87%, and 27.99% for rice, soybean, rape, wheat, maize, and other straw, respectively. Soil available nitrogen and phosphorus influenced the remaining straw C at different decomposition stages. For one calendar year, the total amount of remaining straw C was estimated to be 29.41 Tg and future temperature increase of 2 °C could reduce the remaining straw C by 1.78 Tg. These findings confirmed the long-term straw decomposition could be mainly driven by temperature and straw quality, and quantitatively predicted by thermal time with the three-exponent equation for a wide array of straw types at spatial and temporal

Evaluation of thermophilic fungal consortium for paddy straw composting.

PubMed

Kumar, Adesh; Gaind, Sunita; Nain, Lata

2008-06-01

Out of 10 thermophilic fungi isolated from wheat straw, farm yard manure, and soil, only three showed highest cellobiase, carboxymethyl cellulase, xylanase, and FPase activities. They were identified as Aspergillus nidulans (Th(4)), Scytalidium thermophilum (Th(5)), and Humicola sp. (Th(10)). A fungal consortium of these three fungi was used to compost a mixture (1:1) of silica rich paddy straw and lignin rich soybean trash. The composting of paddy straw for 3 months, during summer period in North India, resulted in a product with C:N ratio 9.5:1, available phosphorus 0.042% and fungal biomass 6.512 mg of N-acetyl glucosamine/100 mg of compost. However, a C:N ratio of 10.2:1 and highest humus content of 3.3% was achieved with 1:1 mixture of paddy straw and soybean trash. The fungal consortium was effective in converting high silica paddy straw into nutritionally rich compost thereby leading to economical and environment friendly disposal of this crop residue.

Solid-state anaerobic co-digestion of spent mushroom substrate with yard trimmings and wheat straw for biogas production.

PubMed

Lin, Yunqin; Ge, Xumeng; Li, Yebo

2014-10-01

Spent mushroom substrate (SMS) is a biomass waste generated from mushroom production. About 5 kg of SMS is generated for every kg of mushroom produced. In this study, solid state anaerobic digestion (SS-AD) of SMS, wheat straw, yard trimmings, and their mixtures was investigated at different feedstock to effluent ratios. SMS was found to be highly degradable, which resulted in inhibition of SS-AD due to volatile fatty acid (VFA) accumulation and a decrease in pH. This issue was addressed by co-digestion of SMS with either yard trimmings or wheat straw. SS-AD of SMS/yard trimmings achieved a cumulative methane yield of 194 L/kg VS, which was 16 and 2 times higher than that from SMS and yard trimmings, respectively. SS-AD of SMS/wheat straw obtained a cumulative methane yield of 269 L/kg VS, which was 23 times as high as that from SMS and comparable to that from wheat straw. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Surface-Modified TiO2 Nanoparticles on the Anti-Ultraviolet Aging Performance of Foamed Wheat Straw Fiber/Polypropylene Composites

PubMed Central

Xuan, Lihui; Han, Guangping; Wang, Dong; Cheng, Wanli; Gao, Xun; Chen, Feng; Li, Qingde

2017-01-01

Surface modification and characterization of titanium dioxide (TiO2) nanoparticles and their roles in thermal, mechanical, and accelerated aging behavior of foamed wheat straw fiber/polypropylene (PP) composites are investigated. To improve the dispersion of nanoparticles and increase the possible interactions between wheat straw fiber and the PP matrix, the surface of the TiO2 nanoparticles was modified with ethenyltrimethoxy silane (A171), a silane coupling agent. The grafting of A171 on the TiO2 nanoparticles’ surface was characterized by Fourier transform infrared spectroscopy (FTIR). The wheat straw fibers treated with A171 and modified TiO2 nanoparticles were characterized by FTIR and thermogravimetric analysis (TGA). FTIR spectra confirmed that the organic functional groups of A171 were successfully grafted onto the TiO2 nanoparticles and wheat straw fibers, and the modified TiO2 nanoparticles were adsorbed onto the wheat straw fibers. Thermogravimetric analysis showed that a higher thermal stability of the wheat straw fiber was obtained with the modified TiO2 nanoparticles. The flexural, tensile, and impact properties were improved. A higher ultraviolet (UV) stability of the samples treated with modified TiO2 nanoparticles was exhibited by the study of the color change and loss in mechanical properties. PMID:28772816

Hydrodynamic cavitation as a novel approach for delignification of wheat straw for paper manufacturing.

PubMed

Badve, Mandar P; Gogate, Parag R; Pandit, Aniruddha B; Csoka, Levente

2014-01-01

The present work deals with application of hydrodynamic cavitation for intensification of delignification of wheat straw as an essential step in the paper manufacturing process. Wheat straw was first treated with potassium hydroxide (KOH) for 48 h and subsequently alkali treated wheat straw was subjected to hydrodynamic cavitation. Hydrodynamic cavitation reactor used in the work is basically a stator and rotor assembly, where the rotor is provided with indentations and cavitational events are expected to occur on the surface of rotor as well as within the indentations. It has been observed that treatment of alkali treated wheat straw in hydrodynamic cavitation reactor for 10-15 min increases the tensile index of the synthesized paper sheets to about 50-55%, which is sufficient for paper board manufacture. The final mechanical properties of the paper can be effectively managed by controlling the processing parameters as well as the cavitational parameters. It has also been established that hydrodynamic cavitation proves to be an effective method over other standard digestion techniques of delignification in terms of electrical energy requirements as well as the required time for processing. Overall, the work is first of its kind application of hydrodynamic cavitation for enhancing the effectiveness of delignification and presents novel results of significant interest to the paper and pulp industry opening an entirely new area of application of cavitational reactors. Copyright © 2013 Elsevier B.V. All rights reserved.

Toward the complete utilization of rice straw: Methane fermentation and lignin recovery by a combinational process involving mechanical milling, supporting material and nanofiltration.

PubMed

Sasaki, Kengo; Okamoto, Mami; Shirai, Tomokazu; Tsuge, Yota; Fujino, Ayami; Sasaki, Daisuke; Morita, Masahiko; Matsuda, Fumio; Kikuchi, Jun; Kondo, Akihiko

2016-09-01

Rice straw was mechanically milled using a process consuming 1.9MJ/kg-biomass, and 10g/L of unmilled or milled rice straw was used as the carbon source for methane fermentation in a digester containing carbon fiber textile as the supporting material. Milling increased methane production from 226 to 419mL/L/day at an organic loading rate of 2180mg-dichromate chemical oxygen demand/L/day, corresponding to 260mLCH4/gVS. Storage of the fermentation effluent at room temperature decreased the weight of the milled rice straw residue from 3.81 to 1.00g/L. The supernatant of the effluent was subjected to nanofiltration. The black concentrates deposited on the nanofiltration membranes contained 53.0-57.9% lignin. Solution nuclear magnetic resonance showed that lignin aromatic components such as p-hydroxyphenyl (H), guaiacyl (G), and syringyl (S) were retained primarily, and major lignin interunit structures such as the β-O-4-H/G unit were absent. This combinational process will aid the complete utilization of rice straw. Copyright © 2016. Published by Elsevier Ltd.

Grinding energy and physical properties of chopped and hammer-milled barley, wheat, oat, and canola straws

DOE Office of Scientific and Technical Information (OSTI.GOV)

J.S. Tumuluru; L.G. Tabil; Y. Song

2014-01-01

In the present study, specific energy for grinding and physical properties of wheat, canola, oat and barley straw grinds were investigated. The initial moisture content of the straw was about 0.13–0.15 (fraction total mass basis). Particle size reduction experiments were conducted in two stages: (1) a chopper without a screen, and (2) a hammer mill using three screen sizes (19.05, 25.4, and 31.75 mm). The lowest grinding energy (1.96 and 2.91 kWh t-1) was recorded for canola straw using a chopper and hammer mill with 19.05-mm screen size, whereas the highest (3.15 and 8.05 kWh t-1) was recorded for barleymore » and oat straws. The physical properties (geometric mean particle diameter, bulk, tapped and particle density, and porosity) of the chopped and hammer-milled wheat, barley, canola, and oat straw grinds measured were in the range of 0.98–4.22 mm, 36–80 kg m-3, 49–119 kg m-3, 600–1220 kg m-3, and 0.9–0.96, respectively. The average mean particle diameter was highest for the chopped wheat straw (4.22-mm) and lowest for the canola grind (0.98-mm). The canola grinds produced using the hammer mill (19.05-mm screen size) had the highest bulk and tapped density of about 80 and 119 kg m-3; whereas, the wheat and oat grinds had the lowest of about 58 and 88–90 kg m-3. The results indicate that the bulk and tapped densities are inversely proportional to the particle size of the grinds. The flow properties of the grinds calculated are better for chopped straws compared to hammer milled using smaller screen size (19.05 mm).« less

Effect of alkali lignins with different molecular weights from alkali pretreated rice straw hydrolyzate on enzymatic hydrolysis.

PubMed

Li, Yun; Qi, Benkun; Luo, Jianquan; Wan, Yinhua

2016-01-01

This study investigated the effect of alkali lignins with different molecular weights on enzymatic hydrolysis of lignocellulose. Different alkali lignins fractions, which were obtained from cascade ultrafiltration, were added into the dilute acid pretreated (DAP) and alkali pretreated (AP) rice straws respectively during enzymatic hydrolysis. The results showed that the addition of alkali lignins enhanced the hydrolysis and the enhancement for hydrolysis increased with increasing molecular weights of alkali lignins, with maximum enhancement being 28.69% for DAP and 20.05% for AP, respectively. The enhancement was partly attributed to the improved cellulase activity, and filter paper activity increased by 18.03% when adding lignin with highest molecular weight. It was found that the enhancement of enzymatic hydrolysis was correlated with the adsorption affinity of cellulase on alkali lignins, and the difference in surface charge and hydrophobicity of alkali lignins were responsible for the difference in affinity between cellulase and lignins. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of electricity generation from lignin residue and biogas in cellulosic ethanol production.

PubMed

Liu, Gang; Bao, Jie

2017-11-01

This study takes the first insight on the rigorous evaluation of electricity generation based on the experimentally measured higher heating value (HHV) of lignin residue, as well as the chemical oxygen demand (COD) and biological oxygen demand (BOD 5 ) of wastewater. For producing one metric ton of ethanol fuel from five typical lignocellulose substrates, including corn stover, wheat straw, rice straw, sugarcane bagasse and poplar sawdust, 1.26-1.85tons of dry lignin residue is generated from biorefining process and 0.19-0.27tons of biogas is generated from anaerobic digestion of wastewater, equivalent to 4335-5981kWh and 1946-2795kWh of electricity by combustion of the generated lignin residue and biogas, respectively. The electricity generation not only sufficiently meets the electricity needs of process requirement, but also generates more than half of electricity surplus selling to the grid. Copyright © 2017 Elsevier Ltd. All rights reserved.

Metataxonomic profiling and prediction of functional behaviour of wheat straw degrading microbial consortia

PubMed Central

2014-01-01

Background Mixed microbial cultures, in which bacteria and fungi interact, have been proposed as an efficient way to deconstruct plant waste. The characterization of specific microbial consortia could be the starting point for novel biotechnological applications related to the efficient conversion of lignocellulose to cello-oligosaccharides, plastics and/or biofuels. Here, the diversity, composition and predicted functional profiles of novel bacterial-fungal consortia are reported, on the basis of replicated aerobic wheat straw enrichment cultures. Results In order to set up biodegradative microcosms, microbial communities were retrieved from a forest soil and introduced into a mineral salt medium containing 1% of (un)treated wheat straw. Following each incubation step, sequential transfers were carried out using 1 to 1,000 dilutions. The microbial source next to three sequential batch cultures (transfers 1, 3 and 10) were analyzed by bacterial 16S rRNA gene and fungal ITS1 pyrosequencing. Faith’s phylogenetic diversity values became progressively smaller from the inoculum to the sequential batch cultures. Moreover, increases in the relative abundances of Enterobacteriales, Pseudomonadales, Flavobacteriales and Sphingobacteriales were noted along the enrichment process. Operational taxonomic units affiliated with Acinetobacter johnsonii, Pseudomonas putida and Sphingobacterium faecium were abundant and the underlying strains were successfully isolated. Interestingly, Klebsiella variicola (OTU1062) was found to dominate in both consortia, whereas K. variicola-affiliated strains retrieved from untreated wheat straw consortia showed endoglucanase/xylanase activities. Among the fungal players with high biotechnological relevance, we recovered members of the genera Penicillium, Acremonium, Coniochaeta and Trichosporon. Remarkably, the presence of peroxidases, alpha-L-fucosidases, beta-xylosidases, beta-mannases and beta-glucosidases, involved in lignocellulose

Natural deep eutectic solvent mediated pretreatment of rice straw: bioanalytical characterization of lignin extract and enzymatic hydrolysis of pretreated biomass residue.

PubMed

Kumar, Adepu K; Parikh, Bhumika S; Pravakar, Mohanty

2016-05-01

The present investigation demonstrated pretreatment of lignocellulosic biomass rice straw using natural deep eutectic solvents (NADESs), and separation of high-quality lignin and holocellulose in a single step. Qualitative analysis of the NADES extract showed that the extracted lignin was of high purity (>90 %), and quantitative analysis showed that nearly 60 ± 5 % (w/w) of total lignin was separated from the lignocellulosic biomass. Addition of 5.0 % (v/v) water during pretreatment significantly enhanced the total lignin extraction, and nearly 22 ± 3 % more lignin was released from the residual biomass into the NADES extract. X-ray diffraction studies of the untreated and pretreated rice straw biomass showed that the crystallinity index ratio was marginally decreased from 46.4 to 44.3 %, indicating subtle structural alterations in the crystalline and amorphous regions of the cellulosic fractions. Thermogravimetric analysis of the pretreated biomass residue revealed a slightly higher T dcp (295 °C) compared to the T dcp (285 °C) of untreated biomass. Among the tested NADES reagents, lactic acid/choline chloride at molar ratio of 5:1 extracted maximum lignin of 68 ± 4 mg g(-1) from the rice straw biomass, and subsequent enzymatic hydrolysis of the residual holocellulose enriched biomass showed maximum reducing sugars of 333 ± 11 mg g(-1) with a saccharification efficiency of 36.0 ± 3.2 % in 24 h at 10 % solids loading.

Hydrothermal pretreatment of several lignocellulosic mixtures containing wheat straw and two hardwood residues available in Southern Europe.

PubMed

Silva-Fernandes, Talita; Duarte, Luís Chorão; Carvalheiro, Florbela; Loureiro-Dias, Maria Conceição; Fonseca, César; Gírio, Francisco

2015-05-01

This work studied the processing of biomass mixtures containing three lignocellulosic materials largely available in Southern Europe, eucalyptus residues (ER), wheat straw (WS) and olive tree pruning (OP). The mixtures were chemically characterized, and their pretreatment, by autohydrolysis, evaluated within a severity factor (logR0) ranging from 1.73 up to 4.24. A simple modeling strategy was used to optimize the autohydrolysis conditions based on the chemical characterization of the liquid fraction. The solid fraction was characterized to quantify the polysaccharide and lignin content. The pretreatment conditions for maximal saccharides recovery in the liquid fraction were at a severity range (logR0) of 3.65-3.72, independently of the mixture tested, which suggests that autohydrolysis can effectively process mixtures of lignocellulosic materials for further biochemical conversion processes. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparison of sodium carbonate-oxygen and sodium hydroxide-oxygen pretreatments on the chemical composition and enzymatic saccharification of wheat straw.

PubMed

Geng, Wenhui; Huang, Ting; Jin, Yongcan; Song, Junlong; Chang, Hou-Min; Jameel, Hasan

2014-06-01

Pretreatment of wheat straw with a combination of sodium carbonate (Na2CO3) or sodium hydroxide (NaOH) with oxygen (O2) 0.5MPa was evaluated for its delignification ability at relatively low temperature 110°C and for its effect on enzymatic hydrolysis efficiency. In the pretreatment, the increase of alkali charge (as Na2O) up to 12% for Na2CO3 and 6% for NaOH, respectively, resulted in enhancement of lignin removal, but did not significantly degrade cellulose and hemicellulose. When the pretreated solid was hydrolyzed with a mixture of cellulases and hemicellulases, the sugar yield increased rapidly with the lignin removal during the pretreatment. A total sugar yield based on dry matter of raw material, 63.8% for Na2CO3-O2 and 71.9% for NaOH-O2 was achieved under a cellulase loading of 20FPU/g-cellulose. The delignification efficiency and total sugar yield from enzymatic hydrolysis were comparable to the previously reported results at much higher temperature without oxygen. Copyright © 2014 Elsevier Ltd. All rights reserved.

Flowability parameters for chopped switchgrass, wheat straw and corn stover

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chevanan, Nehru; Womac, A.R.; Bitra, V.S.P.

2009-02-01

A direct shear cell to measure the shear strength and flow properties of chopped switchgrass, wheat straw, and corn stover was designed, fabricated, and tested. Yield loci (r2=0.99) determined at pre-consolidation pressures of 3.80 kPa and 5.02 kPa indicated that chopped biomass followed Mohr-Coulomb failure. Normal stress significantly affected the displacement required for shear failure, as well as the friction coefficient values for all three chopped biomass types. Displacement at shear failure ranged from 30 to 80 mm, and depended on pre-consolidation pressure, normal stress, and particle size. Friction coefficient was inversely related to normal stress, and was highest formore » chopped corn stover. Also, chopped corn stover exhibited the highest angle of internal friction, unconfined yield strength, major consolidation strength, and cohesive strength, all of which indicated increased challenges in handling chopped corn stover. The measured angle of internal friction and cohesive strength indicated that chopped biomass cannot be handled by gravity alone. The measured angle of internal friction and cohesive strength were 43 and 0.75 kPa for chopped switchgrass; 44 and 0.49 kPa for chopped wheat straw; and 48 and 0.82 kPa for chopped corn stover. Unconfined yield strength and major consolidation strength used for characterization of bulk flow materials and design of hopper dimensions were 3.4 and 10.4 kPa for chopped switchgrass; 2.3 and 9.6 kPa for chopped wheat straw and 4.2 and 11.8 kPa for chopped corn stover. These results are useful for development of efficient handling, storage, and transportation systems for biomass in biorefineries.« less

Effects of rhamnolipid on the cellulase and xylanase in hydrolysis of wheat straw.

PubMed

Wang, Hong-Yuan; Fan, Bing-Quan; Li, Chun-Hua; Liu, Shuang; Li, Min

2011-06-01

The effects of biosurfactant rhamnolipid (RL) and chemical surfactant Triton X-100 on the production of cellulases and xylanase from Penicillium expansum (P. expansum) in untreated, acid- and alkali-pretreated wheat straw submerged fermentations were studied, and the influences on the activity and stability of Cellulase R-10 were also investigated. The results showed that RL and Triton X-100 enhanced the activities of cellulases and xylanase to different extents and the stimulatory effects of RL were superior to those of Triton X-100. During the peak enzyme production phase, RL (60 RE mg/l) increased cellulases activities by 25.5-102.9%, in which the raise of the same enzyme in acid-pretreated straw broths was the most. It was found that the reducing sugars by hydrolyzing wheat straw with Cellulase R-100 were not visibly increased after adding RL. However, it distinctly protected Cellulase R-10 from degradation or inactivation, keeping the reducing sugars yield at about 17%. Copyright © 2011. Published by Elsevier Ltd.

Lignin degradation by selected fungal species.

PubMed

Knežević, Aleksandar; Milovanović, Ivan; Stajić, Mirjana; Lončar, Nikola; Brčeski, Ilija; Vukojević, Jelena; Cilerdžić, Jasmina

2013-06-01

As biological decomposition of plant biomass represents a popular alternative environmental-friendly and economically justified process, screening of ligninolytic enzyme systems of various fungal species is a topical study area. The goal of the study was to obtain clear insight into the dynamics of laccase, Mn-dependent peroxidase, and Mn-independent peroxidase activity and levels of wheat straw lignin degradation in seven wood-rotting fungi. The best laccase producers were Pleurotus ostreatus and Pleurotus eryngii. Lenzites betulinus and Fomitopsis pinicola were the best Mn-dependent peroxidase producers, and P. ostreatus the weakest one. The peak of Mn-independent peroxidase was noted in Dichomytus squalens, and the minimum value in P. ostreatus. The profiles of the three enzymes, obtained by isoelectric focusing, were variable depending on the species and cultivation period. D. squalens was the best lignin degrader (34.1% of total lignin amount), and P. ostreatus and P. eryngii the weakest ones (7.1% and 14.5%, respectively). Copyright © 2013 Elsevier Ltd. All rights reserved.

Syngas production by chemical-looping gasification of wheat straw with Fe-based oxygen carrier.

PubMed

Hu, Jianjun; Li, Chong; Guo, Qianhui; Dang, Jiatao; Zhang, Quanguo; Lee, Duu-Jong; Yang, Yunlong

2018-05-03

The iron-based oxygen carriers (OC's), Fe 2 O 3 /support (Al 2 O 3 , TiO 2 , SiO 2 and ZrO 2 ), for chemical looping gasification of wheat straw were prepared using impregnation method. The surface morphology, crystal structure, carbon deposition potential, lattice oxygen activity and selectivity of the yielded OCs were examined. The Fe 2 O 3 /Al 2 O 3 OCs at 60% loading has the highest H 2 yield, H 2 /CO ratio, gas yield, and carbon conversion amongst the tested OC's. Parametric studies revealed that an optimal loading Fe 2 O 3 of 60%, steam-to-biomass ratio of 0.8 and oxygen carrier-to-biomass ratio of 1.0 led to the maximum H 2 /CO ratio, gas yield, H 2  + CO ratio, and carbon conversion from the gasified wheat straw. High temperature, up to 950 °C, enhanced the gasification performance. A kinetic network interpreted the noted experimental results. The lattice oxygen provided by the prepared Fe 2 O 3 /Al 2 O 3 oxygen carriers promotes chemical looping gasification efficiencies from wheat straw. Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimization of furfural and 5-hydroxymethylfurfural production from wheat straw by a microwave-assisted process.

PubMed

Yemiş, Oktay; Mazza, Giuseppe

2012-04-01

Optimization of acid-catalyzed conversion conditions of wheat straw into furfural, 5-hydroxymethylfurfural (HMF), glucose, and xylose was studied by response surface methodology (RSM). A central composite design (CCD) was used to determine the effects of independent variables, including reaction temperature (140-200 °C), residence time (1-41 min), pH (0.1-2.1), and liquid:solid ratio (15-195 mL/g) on furan and sugar production. The surface response analysis revealed that temperature, time and pH had a strong influence on the furfural, HMF, xylose and glucose yield, whereas liquid to solid ratio was found not to be significant. The initial pH of solution was the most important variable in acid-catalyzed conversion of wheat straw to furans. The maximum predicted furfural, HMF, xylose and glucose yields were 66%, 3.4%, 100%, and 65%, respectively. This study demonstrated that the microwave-assisted process was a very effective method for the xylose production from wheat straw by diluted acid catalysis. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

Ammonia volatilization and atmospheric N deposition following straw and urea application from a rice-wheat rotation in southeastern China

NASA Astrophysics Data System (ADS)

Sun, Liying; Wu, Zhen; Ma, Yuchun; Liu, Yinglie; Xiong, Zhengqin

2018-05-01

Ammonia is a vital component of the nitrogen (N) cycle of terrestrial ecosystems in terms of volatilization and deposition. Here, a field experiment was undertaken to simultaneously investigate the effects of rice straw and urea incorporation on ammonia volatilization, atmospheric N deposition, yields and agronomic nitrogen use efficiency (NUE) under a rice-wheat system in China. The experiment involved four treatments: control (0 N, 0 straw), NS0 (250 kg N ha-1 season-1, 0 straw), NS1 (250 kg N ha-1 season-1, 3 t ha-1 yr-1 straw), and NS2 (250 kg N ha-1 season-1, 6 t ha-1 yr-1 straw) in the rice-wheat annual rotation system. The results indicated that the NS0, NS1 and NS2 treatments emitted cumulative ammonia of 14.0%, 16.4%, and 19.2%, respectively in the rice season and 7.6%, 11.1%, and 12.3%, respectively in the wheat season among the total urea-N application. Compared to the NS0 treatment, the NS1 and NS2 treatments significantly increased the cumulative ammonia emissions by 15.5% (p < 0.05) and 33.5% (p < 0.05), respectively in the rice season and 39.9% (p < 0.05) and 53.1% (p < 0.05), respectively in the wheat season. There was no significant difference between the NS2 and NS1 treatments during the wheat season. The amount of NH4+-N deposition accounted for 56.1% of the total inorganic N deposition during the whole rice-wheat system. The bulk NH4+-N deposition during the period of fertilization contributed 73.9% and 5.7% to the total NH4+-N deposition in the rice and wheat season, respectively. Overall, straw incorporation increased ammonia volatilization, not affecting the crop grain yield or NUE. The seasonal variation in NH4+-N bulk deposition was closely related to N fertilizer application.

Preservation of Ceriporiopsis subvermispora and Lentinula edodes treated wheat straw under anaerobic conditions.

PubMed

Mao, Lei; Sonnenberg, Anton S M; Hendriks, Wouter H; Cone, John W

2018-02-01

No attention has been paid so far to the preservation of fungal-treated lignocellulose for longer periods. In the present study, we treated wheat straw (WS) with the white-rot fungi Ceriporiopsis subvermispora and Lentinula edodes for 8 weeks and assessed changes in pH, chemical composition and in vitro gas production (IVGP) weekly. Fungal-treated WS was also stored for 64 days 'as is', with the addition of lactic acid bacteria (LAB) or with a combination of LAB and molasses in airtight glass jars mimicking ensiling conditions. Both fungi significantly reduced the lignin and hemicellulose content of WS, and increased the cellulose content. The IVGP increased with increasing time of incubation, indicating the increase in digestibility. Both fungi lowered the pH of WS under 4.3, which guarantees an initial and stable low pH during anaerobic storage. Minor changes in fibre composition and IVGP were observed for stored L. edodes treated WS, whereas no change occurred for C. subvermispora. It is possible to conserve C. subvermispora and L. edodes treated straw under anaerobic condition without additives up to 64 days. This finding is important for practical application to supply fungi-treated feed to ruminant animals for a prolonged period. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. © 2017 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Application of bioethanol derived lignin for improving physico-mechanical properties of thermoset biocomposites.

PubMed

Bajwa, Dilpreet S; Wang, Xinnan; Sitz, Evan; Loll, Tyler; Bhattacharjee, Sujal

2016-08-01

Lignin is the most abundant of renewable polymers next to cellulose with a global annual production of 70million tons, largely produced from pulping and second generation biofuel industries. Low value of industrial lignin makes it an attractive biomaterial for wide range of applications. The study investigated the application of wheat straw and corn stover based lignin derived from ethanol production for use in thermoset biocomposites. The biocomposite matrix constituted a two component low viscosity Araldite(®)LY 8601/Aradur(®) 8602 epoxy resin system and the lignin content varied from 0 to 25% by weight fraction. The analysis of the physical and mechanical properties of the biocomposites show bioethanol derived lignin can improve selective properties such as impact strength, and thermal stability without compromising the modulus and strength attributes. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of exogenous xylanase on rumen in vitro gas production and degradability of wheat straw.

PubMed

Togtokhbayar, Norovsambuu; Cerrillo, María A; Rodríguez, Germán Buendía; Elghandour, Mona M M Y; Salem, Abdelfattah Z M; Urankhaich, Chuluunbaatar; Jigjidpurev, Sukhbaatar; Odongo, Nicholas E; Kholif, Ahmed E

2015-08-01

The objective of this study was to determine effects of xylanase on in vitro gas production (GP) and in sacco degradability of wheat straw. Rumen fluid was obtained from three Mongolian native goats fitted with permanent rumen cannulas. The trial consisted of five doses (0, 0.5, 1.0, 1.5, 2.0 μL/g of substrate) of a commercial xylanase (Dyadic® xylanase PLUS, Dyadic International, Inc., Jupiter, FL, USA). For the in sacco degradability, different levels of xylanase enzyme were added directly onto 2 g of wheat straw in nylon bags and incubated in the rumen for 3, 6, 12, 24 and 48 h to estimate degradability of wheat straw. Total GP increased (P < 0.001) at all times of incubation at intermediate levels of xylanase. Methane production had a similar pattern at 3 and 12 h of incubation; increased linearly at 24 h of incubation, and was unaffected at 6 and 48 h of incubation. Rumen NH3 -N concentration increased linearly at 3 h and the highest values were observed with intermediate enzyme levels. All ruminal volatile fatty acids increased linearly with intermediate levels of the fibrolytic enzyme. The in sacco rate of dry matter degradation decreased linearly (P = 0.020) with increasing enzymes. Intermediate levels of xylanase improved rumen kinetic fermentation and degradability. The outcome of this research indicated that the application of xylanase enzyme could improve in vitro GP fermentation of wheat straw. © 2015 Japanese Society of Animal Science.

Methane production from wheat straw with anaerobic sludge by heme supplementation.

PubMed

Xi, Yonglan; Chang, Zhizhou; Ye, Xiaomei; Xu, Rong; Du, Jing; Chen, Guangyin

2014-11-01

Wheat straw particles were directly used as substrate for batch anaerobic digestion with anaerobic sludge under 35°C to evaluate the effects of adding heme on methane production. When 1mg/l heme was added to the fermentation process with no agitated speed, a maximum cumulative methane production of 12227.8ml was obtained with cumulative methane yield of wheat straw was 257.4ml/g-TS (total solid), which was increased by 20.6% compared with 213.5ml/g-TS of no heme was added in the reactor. Meanwhile, oxido-reduction potential (ORP) level was decreased, the activity of coenzyme F420 was significantly improved and NADH/NAD(+) ratio were the highest than other experimental groups. These results suggest that heme-supplemented anaerobic sludge with no agitated speed may be providing a more reductive environment, which is a cost-effective method of anaerobic digestion from biomass waste to produce methane with less energy consuming. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pilot-scale conversion of lime-treated wheat straw into bioethanol: quality assessment of bioethanol and valorization of side streams by anaerobic digestion and combustion

PubMed Central

Maas, Ronald HW; Bakker, Robert R; Boersma, Arjen R; Bisschops, Iemke; Pels, Jan R; de Jong, Ed; Weusthuis, Ruud A; Reith, Hans

2008-01-01

Introduction The limited availability of fossil fuel sources, worldwide rising energy demands and anticipated climate changes attributed to an increase of greenhouse gasses are important driving forces for finding alternative energy sources. One approach to meeting the increasing energy demands and reduction of greenhouse gas emissions is by large-scale substitution of petrochemically derived transport fuels by the use of carbon dioxide-neutral biofuels, such as ethanol derived from lignocellulosic material. Results This paper describes an integrated pilot-scale process where lime-treated wheat straw with a high dry-matter content (around 35% by weight) is converted to ethanol via simultaneous saccharification and fermentation by commercial hydrolytic enzymes and bakers' yeast (Saccharomyces cerevisiae). After 53 hours of incubation, an ethanol concentration of 21.4 g/liter was detected, corresponding to a 48% glucan-to-ethanol conversion of the theoretical maximum. The xylan fraction remained mostly in the soluble oligomeric form (52%) in the fermentation broth, probably due to the inability of this yeast to convert pentoses. A preliminary assessment of the distilled ethanol quality showed that it meets transportation ethanol fuel specifications. The distillation residue, which contained non-hydrolysable and non-fermentable (in)organic compounds, was divided into a liquid and solid fraction. The liquid fraction served as substrate for the production of biogas (methane), whereas the solid fraction functioned as fuel for thermal conversion (combustion), yielding thermal energy, which can be used for heat and power generation. Conclusion Based on the achieved experimental values, 16.7 kg of pretreated wheat straw could be converted to 1.7 kg of ethanol, 1.1 kg of methane, 4.1 kg of carbon dioxide, around 3.4 kg of compost and 6.6 kg of lignin-rich residue. The higher heating value of the lignin-rich residue was 13.4 MJ thermal energy per kilogram (dry basis). PMID

Direct Conversion of Wheat Straw into Electricity with a Biomass Flow Fuel Cell Mediated by Two Redox Ion Pairs.

PubMed

Gong, Jian; Liu, Wei; Du, Xu; Liu, Congmin; Zhang, Zhe; Sun, Feifei; Yang, Le; Xu, Dong; Guo, Hua; Deng, Yulin

2017-02-08

In this paper, a biomass flow fuel cell to directly convert wheat straw to electricity at low temperature (80-90 °C) and atmospheric pressure is presented. Two redox ion pairs, Fe 3+ /Fe 2+ and VO 2 + /VO 2+ , acting as redox catalysts and charge carriers, were used in the anode and cathode flow tanks, respectively. The wheat straw was first oxidized by Fe 3+ in the anode tank at approximately 100 °C. The reduced Fe 2+ in the anode was used to construct a fuel cell with VO 2 + in the cathode. The VO 2 + ions were reduced to VO 2+ and regenerated to VO 2 + by oxygen oxidation. The wheat straw flow fuel cell showed a power output of 100 mW cm -2 . Mediated with liquid Fe 3+ carriers, the solid powder of wheat straw could be gradually degraded into low-molecular-weight organic molecules and even oxidized to CO 2 at the anode without using noble-metal catalysts. The overpotential for the electrodes of the flow fuel cell was examined and the energy cost was estimated. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Pretreating wheat straw by the concentrated phosphoric acid plus hydrogen peroxide (PHP): Investigations on pretreatment conditions and structure changes.

PubMed

Wang, Qing; Hu, Jinguang; Shen, Fei; Mei, Zili; Yang, Gang; Zhang, Yanzong; Hu, Yaodong; Zhang, Jing; Deng, Shihuai

2016-01-01

Wheat straw was pretreated by PHP (the concentrated H3PO4 plus H2O2) to clarify effects of temperature, time and H3PO4 proportion on hemicellulose removal, delignification, cellulose recovery and enzymatic digestibility. Overall, hemicellulose removal was intensified by PHP comparing to the concentrated H3PO4. Moreover, efficient delignification specially happened in PHP pretreatment. Hemicellulose removal and delignification by PHP positively responded to temperature and time. Increasing H3PO4 proportion in PHP can promote hemicellulose removal, however, decrease the delignification. Maximum hemicellulose removal and delignification were achieved at 100% and 83.7% by PHP. Enzymatic digestibility of PHP-pretreated wheat straw was greatly improved by increasing temperature, time and H3PO4 proportion, and complete hydrolysis can be achieved consequently. As temperature of 30-40°C, time of 2.0 h and H3PO4 proportion of 60% were employed, more than 92% cellulose was retained in the pretreated wheat straw, and 29.1-32.6g glucose can be harvested from 100g wheat straw. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effects of ditch-buried straw return on water percolation, nitrogen leaching and crop yields in a rice-wheat rotation system.

PubMed

Yang, Haishui; Xu, Mingmin; Koide, Roger T; Liu, Qian; Dai, Yajun; Liu, Ling; Bian, Xinmin

2016-03-15

Crop residue management and nitrogen loss are two important environmental problems in the rice-wheat rotation system in China. This study investigated the effects of burial of straw on water percolation, nitrogen loss by leaching, crop growth and yield. Greenhouse mesocosm experiments were conducted over the course of three simulated cropping seasons in a rice1-wheat-rice2 rotation. Greater amounts of straw resulted in more water percolation, irrespective of crop season. Burial at 20 and 35 cm significantly reduced, but burial at 50 cm increased nitrogen leaching. Straw at 500 kg ha(-1) reduced, but at 1000 kg ha(-1) and at 1500 kg ha(-1) straw increased nitrogen leaching in three consecutive crop rotations. In addition, straw at 500 kg ha(-1) buried at 35 cm significantly increased yield and its components for both crops. This study suggests that N losses via leaching from the rice-wheat rotation may be reduced by the burial of the appropriate amount of straw at the appropriate depth. Greater amounts of buried straw, however, may promote nitrogen leaching and negatively affect crop growth and yields. Complementary field experiments must be performed to make specific agronomic recommendations. © 2015 Society of Chemical Industry.

Shiitake Medicinal Mushroom, Lentinus edodes (Higher Basidiomycetes) Productivity and Lignocellulolytic Enzyme Profiles during Wheat Straw and Tree Leaf Bioconversion.

PubMed

Elisashvili, Vladimir; Kachlishvili, Eva; Asatiani, Mikheil D

2015-01-01

Two commercial strains of Lentinus edodes have been comparatively evaluated for their productivity and lignocellulolytic enzyme profiles in mushroom cultivation using wheat straw or tree leaves as the growth substrates. Both substrates are profitable for recycling into shiitake fruit bodies. L. edodes 3715 gave the lowest yield of mushroom during tree leaves bioconversion with the biological efficiency (BE) 74.8% while the L. edodes 3721 BE achieved 83.4%. Cultivation of shiitake on wheat straw, especially in the presence of additional nitrogen source, increased the L. edodes 3721 BE to 92-95.3% owing to the high hydrolases activity and favorable conditions. Despite the quantitative variations, each strain of L. edodes had a similar pattern for secreting enzymes into the wheat straw and tree leaves. The mushrooms laccase and MnP activities were high during substrate colonization and declined rapidly during primordia appearance and fruit body development. While oxidase activity decreased, during the same period cellulases and xylanase activity raised sharply. Both cellulase and xylanase activity peaked at the mature fruit body stage. When mushrooms again shifted to the vegetative growth, oxidase activity gradually increased, whereas the hydrolases activity dropped rapidly. The MnP, CMCase, and FP activities of L. edodes 3721 during cultivation on wheat straw were higher than those during mushroom growth on tree leaves whereas the laccase activity was rather higher in fermentation of tree leaves. Enrichment of wheat straw with an additional nitrogen source rather favored to laccase, MnP, and FPA secretion during the vegetative stage of the L. edodes 3721 growth.

Cell-wall structural changes in wheat straw pretreated for bioethanol production

Treesearch

Jan B. Kristensen; G. Thygesen Lisbeth; Claus Felby; Henning Jorgensen; Thomas Elder

2008-01-01

Pretreatment is an essential step in the enzymatic hydrolysis of biomass and subsequent production of bioethanol. Recent results indicate that only a mild pretreatment is necessary in an industrial, economically feasible system. The Integrated Biomass Utilisation System hydrothermal pretreatment process has previously been shown to be effective in preparing wheat straw...

Electron and Fluorescence Microscopy of Extracellular Glucan and Aryl-Alcohol Oxidase during Wheat-Straw Degradation by Pleurotus eryngii

PubMed Central

Barrasa, J. M.; Gutiérrez, A.; Escaso, V.; Guillén, F.; Martínez, M. J.; Martínez, A. T.

1998-01-01

The ligninolytic fungus Pleurotus eryngii grown in liquid medium secreted extracellular polysaccharide (87% glucose) and the H2O2-producing enzyme aryl-alcohol oxidase (AAO). The production of both was stimulated by wheat-straw. Polyclonal antibodies against purified AAO were obtained, and a complex of glucanase and colloidal gold was prepared. With these tools, the localization of AAO and extracellular glucan in mycelium from liquid medium and straw degraded under solid-state fermentation conditions was investigated by transmission electron microscopy (TEM) and fluorescence microscopy. These studies revealed that P. eryngii produces a hyphal sheath consisting of a thin glucan layer. This sheath appeared to be involved in both mycelial adhesion to the straw cell wall during degradation and AAO immobilization on hyphal surfaces, with the latter evidenced by double labeling. AAO distribution during differential degradation of straw tissues was observed by immunofluorescence microscopy. Finally, TEM immunogold studies confirmed that AAO penetrates the plant cell wall during P. eryngii degradation of wheat straw. PMID:9435085

Utilization of the water soluable fraction of wheat straw as a plant nutrient source

NASA Technical Reports Server (NTRS)

Mackowiak, C. L.; Garland, J. L.

1990-01-01

Recovery of water soluble, inorganic nutrients from the inedible portion of wheat was found to be an effective means of recycling nutrients within hydroponic systems. Through aqueous extraction (leaching), 60 percent of the total inorganic nutrient weight was removed from wheat straw and roots, although the recovery of individual nutrients varied. Leaching also removed about 20 percent of the total organic carbon from the biomass. In terms of dry weight, the leachate was comprised of approximately 60 percent organic and 40 percent inorganic compounds. Direct use of wheat straw leachate in static hydroponic systems had an inhibitory effect on wheat growth, both in the presence and absence of microorganisms. Biological treatment of leachate either with a mixed microbial community or the oyster mushroom Pleurotus ostreatus L., prior to use in hydroponic solutions, significantly reduced both the organic content and the inhibitory effects of the leachate. The inhibitory effects of unprocessed leachate appear to be a result of rapidly acting phytotoxic compounds that are detoxified by microbial activity. Leaching holds considerable promise as a method for nutrient recycling in a Controlled Ecological Life Support System (CELSS).

Bioethanol production from wheat straw via enzymatic route employing Penicillium janthinellum cellulases.

PubMed

Singhania, Reeta Rani; Saini, Jitendra Kumar; Saini, Reetu; Adsul, Mukund; Mathur, Anshu; Gupta, Ravi; Tuli, Deepak Kumar

2014-10-01

This study concerns in-house development of cellulases from a mutant Penicillium janthinellum EMS-UV-8 and its application in separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes for bioethanol production from pre-treated wheat straw. In a 5L fermentor, the above strain could produce cellulases having activity of 3.1 FPU/mL and a specific activity of 0.83 FPU/mg of protein. In-house developed cellulase worked more efficiently in case of SSF as ethanol concentration of 21.6g/L and yield of 54.4% were obtained which were higher in comparison to SHF (ethanol concentration 12 g/L and 30.2% yield). This enzyme preparation when compared with commercial cellulase for hydrolysis of pre-treated wheat straw was found competitive. This study demonstrates that P. janthinellum EMS-UV-8 is a potential fungus for future large-scale production of cellulases. Copyright © 2014 Elsevier Ltd. All rights reserved.

Registration of 'Linkert' spring wheat with good straw strength and adult plant resistance to the Ug99 family of stem rust races

USDA-ARS?s Scientific Manuscript database

Straw strength is one of the most important criteria for spring wheat cultivar selection in the north central U.S. ‘Linkert’ (PI 672164) hard red spring wheat was released by the University of Minnesota Agricultural Experiment Station in 2013 and has very good straw strength, high grain protein con...

Treatment of wheat straw using tannase and white-rot fungus to improve feed utilization by ruminants.

PubMed

Raghuwanshi, Shailendra; Misra, Swati; Saxena, Rajendra Kumar

2014-02-20

Current research to enrich cattle feed has primarily focused on treatment using white rot fungi, while there are scarce reports using the enzyme tannase, which is discussed only in reviews or in the form of a hypothesis. In this context, the aim of the present study was to evaluate the effect of tannase on wheat straw (WS) and also the effect of lyophilized tannase at concentrations of 0.1%, 0.2%, and 0.3% (w/w) on WS followed by fermentation with Ganoderma sp. for 10 d and compared in relation to biochemical parameters, crude protein (CP) content, and nutritional value by calculating the C/N ratio in order to improve the nutritional value of cattle feed. Penicillium charlesii, a tannase-producing microorganism, produced 61.4 IU/mL of tannase in 54 h when 2% (w/v) tannic acid (TA) was initially used as a substrate in medium containing (% w/v) sucrose (1.0), NaNO3 (1.0), and MgSO4 (0.08 pH, 5.0) in a 300-L fermentor (working volume 220 L), and concomitantly fed with 1.0% (w/v) TA after 24 h. The yield of partially purified and lyophilized tannase was 5.8 IU/mg. The tannin-free myco-straw at 0.1% (w/w) tannase showed 37.8% (w/w) lignin degradation with only a 20.4% (w/w) decrease in cellulose content and the in vitro feed digestibility was 32.2%. An increase in CP content (up to 1.28-fold) along with a lower C/N ratio of 25.0%, as compared to myco-straw, was obtained. The use of tannin-free myco-straw has potential to improve the nutritional content of cattle feed. This biological treatment process was safe, eco-friendly, easy to perform, and was less expensive as compared to other treatment methods.

Treatment of wheat straw using tannase and white-rot fungus to improve feed utilization by ruminants

PubMed Central

2014-01-01

Background Current research to enrich cattle feed has primarily focused on treatment using white rot fungi, while there are scarce reports using the enzyme tannase, which is discussed only in reviews or in the form of a hypothesis. In this context, the aim of the present study was to evaluate the effect of tannase on wheat straw (WS) and also the effect of lyophilized tannase at concentrations of 0.1%, 0.2%, and 0.3% (w/w) on WS followed by fermentation with Ganoderma sp. for 10 d and compared in relation to biochemical parameters, crude protein (CP) content, and nutritional value by calculating the C/N ratio in order to improve the nutritional value of cattle feed. Results Penicillium charlesii, a tannase-producing microorganism, produced 61.4 IU/mL of tannase in 54 h when 2% (w/v) tannic acid (TA) was initially used as a substrate in medium containing (% w/v) sucrose (1.0), NaNO3 (1.0), and MgSO4 (0.08 pH, 5.0) in a 300-L fermentor (working volume 220 L), and concomitantly fed with 1.0% (w/v) TA after 24 h. The yield of partially purified and lyophilized tannase was 5.8 IU/mg. The tannin-free myco-straw at 0.1% (w/w) tannase showed 37.8% (w/w) lignin degradation with only a 20.4% (w/w) decrease in cellulose content and the in vitro feed digestibility was 32.2%. An increase in CP content (up to 1.28-fold) along with a lower C/N ratio of 25.0%, as compared to myco-straw, was obtained. Conclusions The use of tannin-free myco-straw has potential to improve the nutritional content of cattle feed. This biological treatment process was safe, eco-friendly, easy to perform, and was less expensive as compared to other treatment methods. PMID:24555694

Sequential and simultaneous strategies for biorefining of wheat straw using room temperature ionic liquids, xylanases and cellulases.

PubMed

Husson, Eric; Auxenfans, Thomas; Herbaut, Mickael; Baralle, Manon; Lambertyn, Virginie; Rakotoarivonina, Harivoni; Rémond, Caroline; Sarazin, Catherine

2018-03-01

Sequential and simultaneous strategies for fractioning wheat straw were developed in combining 1-ethyl-3-methyl imidazolium acetate [C2mim][OAc], endo-xylanases from Thermobacillus xylanilyticus and commercial cellulases. After [C2mim][OAc]-pretreatment, hydrolysis catalyzed by endo-xylanases of wheat straw led to efficient xylose production with very competitive yield (97.6 ± 1.3%). Subsequent enzymatic saccharification allowed achieving a total degradation of cellulosic fraction (>99%). These high performances revealed an interesting complementarity of [C2mim][OAc]- and xylanase-pretreatments for increasing enzymatic digestibility of cellulosic fraction in agreement with the structural and morphological changes of wheat straw induced by each of these pretreatment steps. In addition a higher tolerance of endo-xylanases from T. xylaniliticus to [C2mim][AcO] until 30% v/v than cellulases from T. reesei was observed. Based on this property, a simultaneous strategy combining [C2mim][OAc]- and endo-xylanases as pretreatment in a one-batch produced xylose with similar yield than those obtained by the sequential strategy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Isolation, identification and characterization of lignin-degrading bacteria from Qinling, China.

PubMed

Yang, C-X; Wang, T; Gao, L-N; Yin, H-J; Lü, X

2017-12-01

Lignin is an aromatic heteropolymer forming a physical barrier and it is a big challenge in biomass utilization. This paper first investigated lignin-degradation bacteria from rotten wood in Qinling Mountain. Nineteen potential strains were selected and ligninolytic enzyme activities were determined over 84 h. Strains that had higher enzyme activities were selected. Further, the biodegradation of wheat straw lignin and alkali lignin was evaluated indicating that Burkholderia sp. H1 had the highest capability. It was confirmed by gel permeation chromatography and field emission scanning electron microscope that alkali lignin was depolymerized into small fragments. The degraded products were analysed using gas chromatography-mass spectrometry. The total ion chromatograph of products treated for 7 days showed the formation of aromatic compounds, an important intermediate from lignin degradation. Interestingly, they disappeared in 15 days while the aldehyde and ester compounds increased. The results suggest that the lignin-degrading bacteria are abundant in rotten wood and strain H1 has high potential to break down lignin. The diversity of lignin-degrading bacteria in Qinling Mountain is revealed. The study of Burkholderia sp. H1 expands the range of bacteria for lignin degradation and provides novel bacteria for application to lignocellulosic biomass. © 2017 The Society for Applied Microbiology.

Pandoraea sp. B-6 assists the deep eutectic solvent pretreatment of rice straw via promoting lignin depolymerization.

PubMed

Liu, Dan; Yan, Xu; Zhuo, Shengnan; Si, Mengying; Liu, Mingren; Wang, Sheng; Ren, Lili; Chai, Liyuan; Shi, Yan

2018-06-01

Lignin depolymerization is a challenging process in biorefinery due to the recalcitrant and complex structure of lignin. This challenge was herein addressed via elaborating a new strategy of combining the bacterial strain Pandoraea sp. B-6 (hereafter B-6) with a deep eutectic solvent (DES) to pretreat rice straw (RS). In this approach, DES effectively depolymerized lignin yet easily caused sugar loss under severe conditions. B-6 not only overcame the obstacle of lignin droplets, but also significantly improved enzymatic digestibility. After B-6 assisted DES pretreatment, the reducing sugar yield increases by 0.3-1.5 times over DES pretreatment and 0.9-3.1 times over the untreated RS. Furthermore, a "cornhusking" mechanism explaining the improvement of the enzymatic digestibility by B-6 was suggested based on physicochemical characterizations of the untreated and pretreated RS. The findings provided a comprehensive perspective to establish a DES-microbial process for lignocellulose pretreatment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Differential proteomic analysis of the secretome of Irpex lacteus and other white-rot fungi during wheat straw pretreatment.

PubMed

Salvachúa, Davinia; Martínez, Angel T; Tien, Ming; López-Lucendo, María F; García, Francisco; de Los Ríos, Vivian; Martínez, María Jesús; Prieto, Alicia

2013-08-10

Identifying new high-performance enzymes or enzyme complexes to enhance biomass degradation is the key for the development of cost-effective processes for ethanol production. Irpex lacteus is an efficient microorganism for wheat straw pretreatment, yielding easily hydrolysable products with high sugar content. Thus, this fungus was selected to investigate the enzymatic system involved in lignocellulose decay, and its secretome was compared to those from Phanerochaete chrysosporium and Pleurotus ostreatus which produced different degradation patterns when growing on wheat straw. Extracellular enzymes were analyzed through 2D-PAGE, nanoLC/MS-MS, and homology searches against public databases. In wheat straw, I. lacteus secreted proteases, dye-decolorizing and manganese-oxidizing peroxidases, and H2O2 producing-enzymes but also a battery of cellulases and xylanases, excluding those implicated in cellulose and hemicellulose degradation to their monosaccharides, making these sugars poorly available for fungal consumption. In contrast, a significant increase of β-glucosidase production was observed when I. lacteus grew in liquid cultures. P. chrysosporium secreted more enzymes implicated in the total hydrolysis of the polysaccharides and P. ostreatus produced, in proportion, more oxidoreductases. The protein pattern secreted during I. lacteus growth in wheat straw plus the differences observed among the different secretomes, justify the fitness of I. lacteus for biopretreatment processes in 2G-ethanol production. Furthermore, all these data give insight into the biological degradation of lignocellulose and suggest new enzyme mixtures interesting for its efficient hydrolysis.

Lignin Depolymerisation and Lignocellulose Fractionation by Solvated Electrons in Liquid Ammonia.

PubMed

Prinsen, Pepijn; Narani, Anand; Rothenberg, Gadi

2017-03-09

We explored the depolymerisation of several lignins in liquid ammonia at relatively high temperatures and pressures (120 °C and 88 bar). Five different lignins were tested: Indulin AT kraft, Protobind 1000 soda, wheat straw organosolv, poplar organosolv and elephant grass-milled wood lignin (EG MWL). In pure liquid ammonia, all lignins underwent slow incorporation of nitrogen into their structure, resulting in higher molecular weight and polydispersity index. Subsequently, we show a reductive depolymerisation by solvated electrons at room temperature by adding sodium metal to the liquid ammonia without any external hydrogen donor. The netto yields of bio-oil are low for technical lignins (10-23 %), but with higher yields of alkylphenols. In the case of native EG MWL, netto yields of 40 % bio-oil were achieved. Finally, when the room temperature method was applied to poplar wood fibre, we observe improved delignification upon the addition of sodium compared to poplar wood fractionation in pure liquid ammonia. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Growth, carcass yield and meat quality attributes of Red Maasai sheep fed wheat straw-based diets.

PubMed

Safari, John G; Mushi, Daniel E; Mtenga, Louis A; Kifaro, George C; Eik, Lars O

2011-01-01

Thirty-two castrated Red Maasai sheep (12.7 kg initial body weight, aged 12-18 months), were used in an 84-day experiment to evaluate diets based on treated straw upon growth performance, carcass yield and meat quality. The animals were blocked by weight into four similar groups and randomly allotted into four dietary treatments, with eight individually fed animals per treatment. The dietary treatments were ad libitum untreated wheat straw (UTS), wheat straw treated with urea and lime (TS), straw and ad libitum hay (UTSH), and TS and ad libitum hay (TSH). In addition, each experimental animal received 220 g/day (on as fed basis) of a concentrate diet. Treatment of straw increased (P < 0.05) dry matter intake (42.3 vs. 33.7 g/kg W (75)/day), energy intake (4.6 vs. 3.7 MJ ME/d) and the average daily gain (40.7 vs. 23.1 g). Animals on TS produced heavier (P < 0.05) carcasses (6.6 vs. 5.4 kg) with superior conformation than animals on UTS. Percentage cooking loss was higher in carcasses from animals fed TS compared to those from other diets. Except M. longissimus dorsi and M. semitendinosus, tenderness of muscles was not affected by diet but ageing of meat improved (P < 0.001) tenderness. Overall, straw treatment increased carcass yields with limited effects on meat quality attributes.

Effect of Biostimulation Using Sewage Sludge, Soybean Meal, and Wheat Straw on Oil Degradation and Bacterial Community Composition in a Contaminated Desert Soil

PubMed Central

Al-Kindi, Sumaiya; Abed, Raeid M. M.

2016-01-01

Waste materials have a strong potential in the bioremediation of oil-contaminated sites, because of their richness in nutrients and their economical feasibility. We used sewage sludge, soybean meal, and wheat straw to biostimulate oil degradation in a heavily contaminated desert soil. While oil degradation was assessed by following the produced CO2 and by using gas chromatography–mass spectrometry (GC–MS), shifts in bacterial community composition were monitored using illumina MiSeq. The addition of sewage sludge and wheat straw to the desert soil stimulated the respiration activities to reach 3.2–3.4 times higher than in the untreated soil, whereas the addition of soybean meal resulted in an insignificant change in the produced CO2, given the high respiration activities of the soybean meal alone. GC–MS analysis revealed that the addition of sewage sludge and wheat straw resulted in 1.7–1.8 fold increase in the degraded C14 to C30 alkanes, compared to only 1.3 fold increase in the case of soybean meal addition. The degradation of ≥90% of the C14 to C30 alkanes was measured in the soils treated with sewage sludge and wheat straw. MiSeq sequencing revealed that the majority (76.5–86.4% of total sequences) of acquired sequences from the untreated soil belonged to Alphaproteobacteria, Gammaproteobacteria, and Firmicutes. Multivariate analysis of operational taxonomic units placed the bacterial communities of the soils after the treatments in separate clusters (ANOSIM R = 0.66, P = 0.0001). The most remarkable shift in bacterial communities was in the wheat straw treatment, where 95–98% of the total sequences were affiliated to Bacilli. We conclude that sewage sludge and wheat straw are useful biostimulating agents for the cleanup of oil-contaminated desert soils. PMID:26973618

Characterization and swelling-deswelling properties of wheat straw cellulose based semi-IPNs hydrogel.

PubMed

Liu, Jia; Li, Qian; Su, Yuan; Yue, Qinyan; Gao, Baoyu

2014-07-17

A novel wheat straw cellulose-g-poly(potassium acrylate)/polyvinyl alcohol (WSC-g-PKA/PVA) semi-interpenetrating polymer networks (semi-IPNs) hydrogel was prepared by polymerizing wheat straw and an aqueous solution of acrylic acid (AA), and further semi-interpenetrating with PVA occurred during the chemosynthesis. The swelling and deswelling properties of WSC-g-PKA/PVA semi-IPNs hydrogel and WSC-g-PKA hydrogel were studied and compared in various pH solutions, salt solutions, temperatures, particle sizes and ionic strength. The results indicated that both hydrogels had the largest swelling capacity at pH=6, and the effect of ions on the swelling of hydrogels was in the order: Na(+)>K(+)>Mg(2+)>Ca(2+). The Schott's pseudo second order model can be effectively used to evaluate swelling kinetics of hydrogels. Moreover, the semi-IPNs hydrogel had improved swelling-deswelling properties compared with that of WSC-g-PKA hydrogel. Copyright © 2014 Elsevier Ltd. All rights reserved.

Fast modification on wheat straw outer surface by water vapor plasma and its application on composite material.

PubMed

Chen, Weimin; Xu, Yicheng; Shi, Shukai; Cao, Yizhong; Chen, Minzhi; Zhou, Xiaoyan

2018-02-02

The presence of non-poplar extracts, cutin, and wax layer in the wheat straw outer surface (WOS) greatly limit its application in bio-composite preparation. In this study, a dielectric-barrier-discharge plasma using water vapor as feeding gas was used to fast modify the WOS. The morphology, free radical concentrations, surface chemical components, and contact angles of WOS before and after plasma modification were investigated. Wheat straw was further prepared into wheat straw-based composites (WSC) and its bonding strength was evaluated by a paper tension meter. The results showed that water vapor plasma leads to the appearance of surface roughness, the generation of massive free radicals, and the introduction of oxygen-containing groups. In addition, both initial and equilibrium contact angle and the surface total free energy were significantly increased after plasma modification. These results synergistically facilitate the spread and permeation of adhesive onto the WOS and thus improve the bonding strength of all prepared WSCs. A good linear relationship between bonding strength and surface roughness parameters, contact angles, and total free energy were observed. In general, this study provided a time-saving and cost-effective modification method to realize WSC manufacture.

Characterization of the newly isolated Geobacillus sp. T1, the efficient cellulase-producer on untreated barley and wheat straws.

PubMed

Assareh, Reza; Shahbani Zahiri, Hossein; Akbari Noghabi, Kambiz; Aminzadeh, Saeed; Bakhshi Khaniki, Gholamreza

2012-09-01

A thermophile cellulase-producing bacterium was isolated and identified as closely related to Geobacillus subterraneus. The strain, named Geobacillus sp. T1, was able to grow and produce cellulase on cellobiose, microcrystalline cellulose, carboxymethylcellulose (CMC), barley straw, wheat straw and Whatman No. 1 filter paper. However, barley and wheat straws were significantly better substrates for cellulase production. When Geobacillus sp. T1 was cultivated in the presence of 0.5% barley straw, 0.1% Tween 80 and pH 6.5 at 50°C, the maximum level of free cellulase up to 143.50 U/mL was produced after 24h. This cellulase (≈ 54 kDa) was most active at pH 6.5 and 70°C. The enzyme in citrate phosphate buffer (10mM) was stable at 60°C for at least 1h. Geobacillus sp. T1 with efficient growth and cellulase production on straws seems a potential candidate for conversion of agricultural biomass to fuels. Copyright © 2012 Elsevier Ltd. All rights reserved.

Influence of Wheat Straw Pelletizing and Inclusion Rate in Dry Rolled or Steam-flaked Corn-based Finishing Diets on Characteristics of Digestion for Feedlot Cattle.

PubMed

Manríquez, O M; Montano, M F; Calderon, J F; Valdez, J A; Chirino, J O; Gonzalez, V M; Salinas-Chavira, J; Mendoza, G D; Soto, S; Zinn, R A

2016-06-01

Eight Holstein steers (216±48 kg body weight) fitted with ruminal and duodenal cannulas were used to evaluate effects of wheat straw processing (ground vs pelleted) at two straw inclusion rates (7% and 14%; dry matter basis) in dry rolled or steam-flaked corn-based finishing diets on characteristics of digestion. The experimental design was a split plot consisting of two simultaneous 4×4 Latin squares. Increasing straw level reduced ruminal (p<0.01) and total tract (p = 0.03) organic matter (OM) digestion. As expected, increasing wheat straw level from 7% to 14% decreased (p<0.05) ruminal and total tract digestion of OM. Digestion of neutral detergent fiber (NDF) and starch, per se, were not affected (p>0.10) by wheat straw level. Likewise, straw level did not influence ruminal acetate and propionate molar proportions or estimated methane production (p>0.10). Pelleting straw did not affect (p≥0.48) ruminal digestion of OM, NDF, and starch, or microbial efficiency. Ruminal feed N digestion was greater (7.4%; p = 0.02) for ground than for pelleted wheat straw diets. Although ruminal starch digestion was not affected by straw processing, post-ruminal (p<0.01), and total-tract starch (p = 0.05) digestion were greater for ground than for pelleted wheat straw diets, resulting in a tendency for increased post-ruminal (p = 0.06) and total tract (p = 0.07) OM digestion. Pelleting wheat straw decreased (p<0.01) ruminal pH, although ruminal volatile fatty acids (VFA) concentration and estimated methane were not affected (p≥0.27). Ruminal digestion of OM and starch, and post-ruminal and total tract digestion of OM, starch and N were greater (p<0.01) for steam-flaked than for dry rolled corn-based diets. Ruminal NDF digestion was greater (p = 0.02) for dry rolled than for steam-flaked corn, although total tract NDF digestion was unaffected (p = 0.94). Ruminal microbial efficiency and ruminal degradation of feed N were not affected (p>0.14) by corn processing. However

Performance Monitoring: Evaluating a Wheat Straw PRB for Nitrate Removal at an Agricultural Operation

EPA Science Inventory

The U.S. EPA Office of Research and Development’s National Risk Management Research Laboratory (NRMRL) is conducting long-term monitoring of a wheat straw permeable reactive barrier (PRB) for remediation of ground water contaminated with nitrate from a now-closed swine concentrat...

Characterization of mixing and yield stress of pretreated wheat straw slurries used for the production of biofuels through tomography technique.

PubMed

Naghavi-Anaraki, Yasaman; Turcotte, Ginette; Ein-Mozaffari, Farhad

2018-05-29

Wheat straw is a low-cost feedstock for the production of biofuel. Pretreatment process is an important stage in producing biofuels since it makes the fibers more accessible to enzymatic hydrolysis which is the final step of producing biofuels. Pretreated wheat straw (PWS) slurries are non-Newtonian fluids with yield stress. Mixing of fluids exhibiting yield stress such as the pretreated wheat straw slurry results in the generation of cavern, which is a fully-mixed zone, around the impeller and the stationary regions elsewhere, which causes difficulties in the production of biofuels. In this study, the non-invasive electrical resistance tomography technique was utilized to determine the cavern dimensions as a function of the impeller type and impeller speed. The cavern sizes were then used to measure the yield stress of PWS slurries as a function of fiber size (≤ 2 and ≤ 6 mm) and fiber concentration (6, 8, and 10 wt%).

Adsorptive Removal of Toxic Chromium from Waste-Water Using Wheat Straw and Eupatorium adenophorum

PubMed Central

Song, Dagang; Pan, Kaiwen; Tariq, Akash; Azizullah, Azizullah; Sun, Feng; Li, Zilong; Xiong, Qinli

2016-01-01

Environmental pollution with heavy metals is a serious issue worldwide posing threats to humans, animals and plants and to the stability of overall ecosystem. Chromium (Cr) is one of most hazardous heavy metals with a high carcinogenic and recalcitrant nature. Aim of the present study was to select low-cost biosorbent using wheat straw and Eupatorium adenophorum through simple carbonization process, capable of removing Cr (VI) efficiently from wastewater. From studied plants a low cost adsorbent was prepared for removing Cr (VI) from aqueous solution following very simple carbonization method excluding activation process. Several factors such as pH, contact time, sorbent dosage and temperature were investigated for attaining ideal condition. For analysis of adsorption equilibrium isotherm data, Langmuir, Freundlich and Temkin models were used while pseudo-first-order, pseudo-second-order, external diffusion and intra-particle diffusion models were used for the analysis of kinetic data. The obtained results revealed that 99.9% of Cr (VI) removal was observed in the solution with a pH of 1.0. Among all the tested models Langmuir model fitted more closely according to the data obtained. Increase in adsorption capacity was observed with increasing temperature revealing endothermic nature of Cr (VI). The maximum Cr (VI) adsorption potential of E. adenophorum and wheat straw was 89.22 mg per 1 gram adsorbent at 308K. Kinetic data of absorption precisely followed pseudo-second-order model. Present study revealed highest potential of E. adenophorum and wheat straw for producing low cost adsorbent and to remove Cr (VI) from contaminated water. PMID:27911906

Adsorptive Removal of Toxic Chromium from Waste-Water Using Wheat Straw and Eupatorium adenophorum.

PubMed

Song, Dagang; Pan, Kaiwen; Tariq, Akash; Azizullah, Azizullah; Sun, Feng; Li, Zilong; Xiong, Qinli

2016-01-01

Environmental pollution with heavy metals is a serious issue worldwide posing threats to humans, animals and plants and to the stability of overall ecosystem. Chromium (Cr) is one of most hazardous heavy metals with a high carcinogenic and recalcitrant nature. Aim of the present study was to select low-cost biosorbent using wheat straw and Eupatorium adenophorum through simple carbonization process, capable of removing Cr (VI) efficiently from wastewater. From studied plants a low cost adsorbent was prepared for removing Cr (VI) from aqueous solution following very simple carbonization method excluding activation process. Several factors such as pH, contact time, sorbent dosage and temperature were investigated for attaining ideal condition. For analysis of adsorption equilibrium isotherm data, Langmuir, Freundlich and Temkin models were used while pseudo-first-order, pseudo-second-order, external diffusion and intra-particle diffusion models were used for the analysis of kinetic data. The obtained results revealed that 99.9% of Cr (VI) removal was observed in the solution with a pH of 1.0. Among all the tested models Langmuir model fitted more closely according to the data obtained. Increase in adsorption capacity was observed with increasing temperature revealing endothermic nature of Cr (VI). The maximum Cr (VI) adsorption potential of E. adenophorum and wheat straw was 89.22 mg per 1 gram adsorbent at 308K. Kinetic data of absorption precisely followed pseudo-second-order model. Present study revealed highest potential of E. adenophorum and wheat straw for producing low cost adsorbent and to remove Cr (VI) from contaminated water.

Flocculation of wheat straw soda lignin by hemoglobin and chicken blood: Effects of cationic polymer or calcium chloride

USDA-ARS?s Scientific Manuscript database

Flocculation can be used to separate non-sulfonated lignin from base hydrolyzed biomass. In the industrial process, the lignin is isolated by filtration and washed with water. Some of the lignin is lost in the wash water, and flocculation can be used to recover this lignin. Several ways of enhanc...

Biomass yield and feeding value of rye, triticale, and wheat straw produced under a dual-purpose management system.

PubMed

Ates, S; Keles, G; Demirci, U; Dogan, S; Ben Salem, H

2017-11-01

Dual-purpose management of winter cereals for grazing and grain production provides highly nutritive forage for ruminants in the spring and may positively affect straw feeding value. A 2-yr study investigated the effect of spring defoliation of triticale, wheat, and rye at the tillering and stem elongation stages on total biomass, grain yields, and straw quality. Furthermore, straws of spring-defoliated and undefoliated (control) cereal crops were evaluated for nutritional value and voluntary intake as a means of assessing the efficiency of dual-purpose management systems from the winter feeding context as well. The feeding study consisted of 9 total mixed rations (TMR), each containing 35% triticale, rye, or wheat straw obtained under 3 spring-defoliation regimens. The TMR were individually fed to fifty-four 1-yr-old Anatolian Merino ewes for 28 d. Defoliation of the crops at tillering did not affect the total biomass production or grain yields. However, biomass and grain yields were reduced ( < 0.01) by 55 and 52%, respectively, in crops defoliated at stem elongation. Straw of spring-defoliated cereals had less NDF and ADF concentrations ( < 0.01) but greater CP ( < 0.01), nonfiber carbohydrates ( < 0.01), and ME concentrations ( < 0.01) compared with straw from undefoliated crops. The increase in the nutritive value of straw led to greater nutrient digestion ( < 0.01) and intake of DM and OM of ewes ( < 0.01). However, sheep live weight gain did not differ among treatments ( > 0.77). This study indicated that straw feeding value and digestibility can be increased through spring defoliation.

Direct ethanol production from starch, wheat bran and rice straw by the white rot fungus Trametes hirsuta.

PubMed

Okamoto, Kenji; Nitta, Yasuyuki; Maekawa, Nitaro; Yanase, Hideshi

2011-03-07

The white rot fungus Trametes hirsuta produced ethanol from a variety of hexoses: glucose, mannose, cellobiose and maltose, with yields of 0.49, 0.48, 0.47 and 0.47 g/g of ethanol per sugar utilized, respectively. In addition, this fungus showed relatively favorable xylose consumption and ethanol production with a yield of 0.44 g/g. T. hirsuta was capable of directly fermenting starch, wheat bran and rice straw to ethanol without acid or enzymatic hydrolysis. Maximum ethanol concentrations of 9.1, 4.3 and 3.0 g/l, corresponding to 89.2%, 78.8% and 57.4% of the theoretical yield, were obtained when the fungus was grown in a medium containing 20 g/l starch, wheat bran or rice straw, respectively. The fermentation of rice straw pretreated with ball milling led to a small improvement in the ethanol yield: 3.4 g ethanol/20 g ball-milled rice straw. As T. hirsuta is an efficient microorganism capable of hydrolyzing biomass to fermentable sugars and directly converting them to ethanol, it may represent a suitable microorganism in consolidated bioprocessing applications. Copyright © 2010 Elsevier Inc. All rights reserved.

Relationship of deoxynivalenol content in grain, chaff, and straw with Fusarium head blight severity in wheat varieties with various levels of resistance.

PubMed

Ji, Fang; Wu, Jirong; Zhao, Hongyan; Xu, Jianhong; Shi, Jianrong

2015-03-05

A total of 122 wheat varieties obtained from the Nordic Genetic Resource Center were infected artificially with an aggressive Fusariumasiaticum strain in a field experiment. We calculated the severity of Fusarium head blight (FHB) and determined the deoxynivalenol (DON) content of wheat grain, straw and glumes. We found DON contamination levels to be highest in the glumes, intermediate in the straw, and lowest in the grain in most samples. The DON contamination levels did not increase consistently with increased FHB incidence. The DON levels in the wheat varieties with high FHB resistance were not necessarily low, and those in the wheat varieties with high FHB sensitivity were not necessarily high. We selected 50 wheat genotypes with reduced DON content for future research. This study will be helpful in breeding new wheat varieties with low levels of DON accumulation.

Pretreating wheat straw by phosphoric acid plus hydrogen peroxide for enzymatic saccharification and ethanol production at high solid loading.

PubMed

Qiu, Jingwen; Ma, Lunjie; Shen, Fei; Yang, Gang; Zhang, Yanzong; Deng, Shihuai; Zhang, Jing; Zeng, Yongmei; Hu, Yaodong

2017-08-01

Wheat straw was pretreated by phosphoric acid plus hydrogen peroxide (PHP) for enzymatic hydrolysis and ethanol fermentation at high solid loadings. Results indicated solid loading could reach 20% with 77.4% cellulose-glucose conversion and glucose concentration of 164.9g/L in hydrolysate, it even was promoted to 25% with only 3.4% decrease on cellulose-glucose conversion as the pretreated-wheat straw was dewatered by air-drying. 72.9% cellulose-glucose conversion still was achieved as the minimized enzyme input of 20mg protein/g cellulose was employed for hydrolysis at 20% solid loading. In the corresponding conditions, 100g wheat straw can yield 11.2g ethanol with concentration of 71.2g/L by simultaneous saccharification and fermentation. Thus, PHP-pretreatment benefitted the glucose or ethanol yield at high solid loadings with lower enzyme input. Additionally, decreases on the maximal cellulase adsorption and the direct-orange/direct-blue indicated drying the PHP-pretreated substrates negatively affected the hydrolysis due to the shrinkage of cellulase-size-accommodable pores. Copyright © 2017 Elsevier Ltd. All rights reserved.

Urea plus nitrate pretreatment of rice and wheat straws enhances degradation and reduces methane production in in vitro ruminal culture.

PubMed

Zhang, Xiumin; Wang, Min; Wang, Rong; Ma, Zhiyuan; Long, Donglei; Mao, Hongxiang; Wen, Jiangnan; Bernard, Lukuyu A; Beauchemin, Karen A; Tan, Zhiliang

2018-04-10

Urea pretreatment of straw damages fiber structure, while nitrate supplementation of ruminal diets inhibits enteric methane production. The study examined the combined effects of these treatments on ruminal substrate biodegradation and methane production using an in vitro incubation system. Rice and wheat straws were pretreated with urea (40 g kg -1 straw dry matter, DM) and urea + ammonium nitrate (34 + 6 g kg -1 dry matter (DM), respectively), and each straw (control, urea, urea+nitrate) was used in batch culture incubations in three replications (runs). Urea pretreatment increased (P < 0.05) neutral-detergent solubles (NDS) content (+17%) and in vitro DM degradation of rice straw, in comparison with control. Urea+nitrate pretreatment of rice and wheat straws had higher (P < 0.05) NDS content, in vitro DM degradation and propionate molar proportion, and lower (P < 0.05) acetate:propionate ratio and lower methane production with a decline of methanogens, in comparison to control. Urea+nitrate pretreatment combines positive effects of urea pretreatment and nitrate supplementation, and can be a potential strategy to improve ruminal biodegradation, facilitate propionate production and reduce methane production from lignified straws. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

Enhanced biomethane potential from wheat straw by low temperature alkaline calcium hydroxide pre-treatment.

PubMed

Reilly, Matthew; Dinsdale, Richard; Guwy, Alan

2015-08-01

A factorially designed experiment to examine the effectiveness of Ca(OH)2 pre-treatment, enzyme addition and particle size, on the mesophilic (35 °C) anaerobic digestion of wheat straw was conducted. Experiments used a 48 h pre-treatment with Ca(OH)2 7.4% (w/w), addition of Accellerase®-1500, with four particle sizes of wheat straw (1.25, 2, 3 and 10mm) and three digestion time periods (5, 15 and 30 days). By combining particle size reduction and Ca(OH)2 pre-treatment, the average methane potential was increased by 315% (from 48 NmL-CH4 g-VS(-1) to 202 NmL-CH4 g-VS(-1)) after 5 days of anaerobic digestion compared to the control. Enzyme addition or Ca(OH)2 pre-treatment with 3, 2 and 1.25 mm particle sizes had 30-day batch yields of between 301 and 335 NmL-CH4 g-VS(-1). Alkali pre-treatment of 3mm straw was shown to have the most potential as a cost effective pre-treatment and achieved 290 NmL-CH4 g-VS(-1), after only 15 days of digestion. Copyright © 2015 Elsevier Ltd. All rights reserved.

Biorefining strategy for maximal monosaccharide recovery from three different feedstocks: eucalyptus residues, wheat straw and olive tree pruning.

PubMed

Silva-Fernandes, Talita; Duarte, Luís Chorão; Carvalheiro, Florbela; Marques, Susana; Loureiro-Dias, Maria Conceição; Fonseca, César; Gírio, Francisco

2015-05-01

This work proposes the biorefining of eucalyptus residues (ER), wheat straw (WS) and olive tree pruning (OP) combining hydrothermal pretreatment (autohydrolysis) with acid post-hydrolysis of the liquid fraction and enzymatic hydrolysis of the solid fraction towards maximal recovery of monosaccharides from those lignocellulose materials. Autohydrolysis of ER, WS and OP was performed under non-isothermal conditions (195-230°C) and the non-cellulosic saccharides were recovered in the liquid fraction while cellulose and lignin remained in the solid fraction. The acid post-hydrolysis of the soluble oligosaccharides was studied by optimizing sulfuric acid concentration (1-4%w/w) and reaction time (10-60 min), employing a factorial (2(2)) experimental design. The solids resulting from pretreatment were submitted to enzymatic hydrolysis by applying commercial cellulolytic enzymes Celluclast® 1.5L and Novozyme® 188 (0.225 and 0.025 g/g solid, respectively). This strategy provides high total monosaccharide recovery or high glucose recovery from lignocellulosic materials, depending on the autohydrolysis conditions applied. Copyright © 2015 Elsevier Ltd. All rights reserved.

Hydrothermal carbonization (HTC) of wheat straw: influence of feedwater pH prepared by acetic acid and potassium hydroxide.

PubMed

Reza, M Toufiq; Rottler, Erwin; Herklotz, Laureen; Wirth, Benjamin

2015-04-01

In this study, influence of feedwater pH (2-12) was studied for hydrothermal carbonization (HTC) of wheat straw at 200 and 260°C. Acetic acid and KOH were used as acidic and basic medium, respectively. Hydrochars were characterized by elemental and fiber analyses, SEM, surface area, pore volume and size, and ATR-FTIR, while HTC process liquids were analyzed by HPLC and GC. Both hydrochar and HTC process liquid qualities vary with feedwater pH. At acidic pH, cellulose and elemental carbon increase in hydrochar, while hemicellulose and pseudo-lignin decrease. Hydrochars produced at pH 2 feedwater has 2.7 times larger surface area than that produced at pH 12. It also has the largest pore volume (1.1 × 10(-1) ml g(-1)) and pore size (20.2 nm). Organic acids were increasing, while sugars were decreasing in case of basic feedwater, however, phenolic compounds were present only at 260°C and their concentrations were increasing in basic feedwater. Copyright © 2015 Elsevier Ltd. All rights reserved.

Recovery of wheat straw soda lignin using flocculation by proteins, synthetic flocculants, and a metal coagulant

USDA-ARS?s Scientific Manuscript database

Non-sulfonated lignin, a byproduct of biomass conversion to fuel ethanol, is finding increasing applications and can be converted to chemical substances which replace those obtained from petrochemicals. To date, most studies of flocculant function on non-sulfonated lignin have used mixtures of lign...

Alkali-explosion pretreatment of straw and bagasse for enzymic hydrolysis.

PubMed

Puri, V P; Pearce, G R

1986-04-01

Sugarcane bagasse and wheat straw were subjected to alkali treatment at 200 degrees C for 5 min and at 3.45 MPa gas pressure (steam and nitrogen), followed by an explosive discharge through a defibrating nozzle, in an attempt to improve the rate and extent of digestibility. The treatment resulted in the solubilization of 40-45% of the components and in the production of a pulp that gave saccharification yields of 80 and 65% in 8 h for bagasse and wheat straw, respectively. By comparison, alkali steaming at 200 degrees C (1.72 MPa) for 5 min gave saccharification yields of only 58 and 52% in 48 h. The increase in temperature from 140 to 200 degrees C resulted in a gradual increase in in vitro organic matter digestibility (IVOMD) for both the substrates. Also, the extent of alkalinity during pretreatment appears to effect the reactivity of the final product towards enzymes. Pretreatment times ranging from 5 to 60 caused a progressive decline in the IVOMD of bagasse and wheat straw by the alkali explosion method and this was accompanied by a progressive decrease in pH values after explosion. In the alkali-steaming method, pretreatment time had no apparent effect with either substrate. An analysis of the alkali-exploded products showed that substantial amounts of hemicellulose and a small proportion of the lignin were solubilized. The percentage crystallinity of the cellulose did not alter in either substrate but there was a substantial reduction in the degree of polymerization. The superiority of the alkali-explosion pretreatment is attributed to the efficacy of fiber separation and disintegration; this increases the surface area and reduces the degree of polymerization.

Chemical Pretreatment-Independent Saccharifications of Xylan and Cellulose of Rice Straw by Bacterial Weak Lignin-Binding Xylanolytic and Cellulolytic Enzymes

PubMed Central

Teeravivattanakit, Thitiporn; Baramee, Sirilak; Phitsuwan, Paripok; Sornyotha, Somphit; Waeonukul, Rattiya; Pason, Patthra; Tachaapaikoon, Chakrit; Poomputsa, Kanokwan; Kosugi, Akihiko; Sakka, Kazuo

2017-01-01

ABSTRACT Complete utilization of carbohydrate fractions is one of the prerequisites for obtaining economically favorable lignocellulosic biomass conversion. This study shows that xylan in untreated rice straw was saccharified to xylose in one step without chemical pretreatment, yielding 58.2% of the theoretically maximum value by Paenibacillus curdlanolyticus B-6 PcAxy43A, a weak lignin-binding trifunctional xylanolytic enzyme, endoxylanase/β-xylosidase/arabinoxylan arabinofuranohydrolase. Moreover, xylose yield from untreated rice straw was enhanced to 78.9% by adding endoxylanases PcXyn10C and PcXyn11A from the same bacterium, resulting in improvement of cellulose accessibility to cellulolytic enzyme. After autoclaving the xylanolytic enzyme-treated rice straw, it was subjected to subsequent saccharification by a combination of the Clostridium thermocellum endoglucanase CtCel9R and Thermoanaerobacter brockii β-glucosidase TbCglT, yielding 88.5% of the maximum glucose yield, which was higher than the glucose yield obtained from ammonia-treated rice straw saccharification (59.6%). Moreover, this work presents a new environment-friendly xylanolytic enzyme pretreatment for beneficial hydrolysis of xylan in various agricultural residues, such as rice straw and corn hull. It not only could improve cellulose saccharification but also produced xylose, leading to an improvement of the overall fermentable sugar yields without chemical pretreatment. IMPORTANCE Ongoing research is focused on improving “green” pretreatment technologies in order to reduce energy demands and environmental impact and to develop an economically feasible biorefinery. The present study showed that PcAxy43A, a weak lignin-binding trifunctional xylanolytic enzyme, endoxylanase/β-xylosidase/arabinoxylan arabinofuranohydrolase from P. curdlanolyticus B-6, was capable of conversion of xylan in lignocellulosic biomass such as untreated rice straw to xylose in one step without chemical pretreatment

Chemical Pretreatment-Independent Saccharifications of Xylan and Cellulose of Rice Straw by Bacterial Weak Lignin-Binding Xylanolytic and Cellulolytic Enzymes.

PubMed

Teeravivattanakit, Thitiporn; Baramee, Sirilak; Phitsuwan, Paripok; Sornyotha, Somphit; Waeonukul, Rattiya; Pason, Patthra; Tachaapaikoon, Chakrit; Poomputsa, Kanokwan; Kosugi, Akihiko; Sakka, Kazuo; Ratanakhanokchai, Khanok

2017-11-15

Complete utilization of carbohydrate fractions is one of the prerequisites for obtaining economically favorable lignocellulosic biomass conversion. This study shows that xylan in untreated rice straw was saccharified to xylose in one step without chemical pretreatment, yielding 58.2% of the theoretically maximum value by Paenibacillus curdlanolyticus B-6 PcAxy43A, a weak lignin-binding trifunctional xylanolytic enzyme, endoxylanase/β-xylosidase/arabinoxylan arabinofuranohydrolase. Moreover, xylose yield from untreated rice straw was enhanced to 78.9% by adding endoxylanases PcXyn10C and PcXyn11A from the same bacterium, resulting in improvement of cellulose accessibility to cellulolytic enzyme. After autoclaving the xylanolytic enzyme-treated rice straw, it was subjected to subsequent saccharification by a combination of the Clostridium thermocellum endoglucanase CtCel9R and Thermoanaerobacter brockii β-glucosidase TbCglT, yielding 88.5% of the maximum glucose yield, which was higher than the glucose yield obtained from ammonia-treated rice straw saccharification (59.6%). Moreover, this work presents a new environment-friendly xylanolytic enzyme pretreatment for beneficial hydrolysis of xylan in various agricultural residues, such as rice straw and corn hull. It not only could improve cellulose saccharification but also produced xylose, leading to an improvement of the overall fermentable sugar yields without chemical pretreatment. IMPORTANCE Ongoing research is focused on improving "green" pretreatment technologies in order to reduce energy demands and environmental impact and to develop an economically feasible biorefinery. The present study showed that PcAxy43A, a weak lignin-binding trifunctional xylanolytic enzyme, endoxylanase/β-xylosidase/arabinoxylan arabinofuranohydrolase from P. curdlanolyticus B-6, was capable of conversion of xylan in lignocellulosic biomass such as untreated rice straw to xylose in one step without chemical pretreatment. It

Oxidation in Acidic Medium of Lignins from Agricultural Residues

NASA Astrophysics Data System (ADS)

Labat, Gisele Aparecida Amaral; Gonçalves, Adilson Roberto

Agricultural residues as sugarcane straw and bagasse are burned in boilers for generation of energy in sugar and alcohol industries. However, excess of those by-products could be used to obtain products with higher value. Pulping process generates cellulosic pulps and lignin. The lignin could be oxidized and applied in effluent treatments for heavy metal removal. Oxidized lignin presents very strong chelating properties. Lignins from sugarcane straw and bagasse were obtained by ethanol-water pulping. Oxidation of lignins was carried out using acetic acid and Co/Mn/Br catalytical system at 50, 80, and 115 °C for 5 h. Kinetics of the reaction was accomplished by measuring the UV-visible region. Activation energy was calculated for lignins from sugarcane straw and bagasse (34.2 and 23.4 kJ mol-1, respectively). The first value indicates higher cross-linked formation. Fourier-transformed infrared spectroscopy data of samples collected during oxidation are very similar. Principal component analysis applied to spectra shows only slight structure modifications in lignins after oxidation reaction.

Laccase SilA from Streptomyces ipomoeae CECT 3341, a key enzyme for the degradation of lignin from agricultural residues?

PubMed Central

Blánquez, Alba; Ball, Andrew S.; González-Pérez, José Antonio; Jiménez-Morillo, Nicasio T.; González-Vila, Francisco; Arias, M. Enriqueta

2017-01-01

The role of laccase SilA produced by Streptomyces ipomoeae CECT 3341 in lignocellulose degradation was investigated. A comparison of the properties and activities of a laccase-negative mutant strain (SilA−) with that of the wild-type was studied in terms of their ability to degrade lignin from grass lignocellulose. The yields of solubilized lignin (acid precipitable polymeric lignin, APPL) obtained from wheat straw by both strains in Solid State Fermentation (SSF) conditions demonstrated the importance of SilA laccase in lignin degradation with the wild-type showing 5-fold more APPL produced compared with the mutant strain (SilA−). Analytical pyrolysis and FT-IR (Fourier Transform Infrared Spectroscopy) confirmed that the APPL obtained from the substrate fermented by wild-type strain was dominated by lignin derived methoxyphenols whereas those from SilA− and control APPLs were composed mainly of polysaccharides. This is the first report highlighting the role of this laccase in lignin degradation. PMID:29112957

Laccase SilA from Streptomyces ipomoeae CECT 3341, a key enzyme for the degradation of lignin from agricultural residues?

PubMed

Blánquez, Alba; Ball, Andrew S; González-Pérez, José Antonio; Jiménez-Morillo, Nicasio T; González-Vila, Francisco; Arias, M Enriqueta; Hernández, Manuel

2017-01-01

The role of laccase SilA produced by Streptomyces ipomoeae CECT 3341 in lignocellulose degradation was investigated. A comparison of the properties and activities of a laccase-negative mutant strain (SilA-) with that of the wild-type was studied in terms of their ability to degrade lignin from grass lignocellulose. The yields of solubilized lignin (acid precipitable polymeric lignin, APPL) obtained from wheat straw by both strains in Solid State Fermentation (SSF) conditions demonstrated the importance of SilA laccase in lignin degradation with the wild-type showing 5-fold more APPL produced compared with the mutant strain (SilA-). Analytical pyrolysis and FT-IR (Fourier Transform Infrared Spectroscopy) confirmed that the APPL obtained from the substrate fermented by wild-type strain was dominated by lignin derived methoxyphenols whereas those from SilA- and control APPLs were composed mainly of polysaccharides. This is the first report highlighting the role of this laccase in lignin degradation.

An economic evaluation of biological conversion of wheat straw to butanol: A biofuel

USDA-ARS?s Scientific Manuscript database

A cost estimation study was performed for a biological butanol production plant with a capacity of 150 x 10**6 kg butanol/year. Wheat straw was used as a feedstock. In addition to butanol, acetone (78.05 x 10**6 kg/year) and ethanol (28.54 x 10**6 kg/year) would also be produced. The total capital c...

Modifying sulfomethylated alkali lignin by horseradish peroxidase to improve the dispersibility and conductivity of polyaniline

NASA Astrophysics Data System (ADS)

Yang, Dongjie; Huang, Wenjing; Qiu, Xueqing; Lou, Hongming; Qian, Yong

2017-12-01

Pine and wheat straw alkali lignin (PAL and WAL) were sulfomethylated to improve water solubility, polymerized with horseradish peroxidase (HRP) to improve the molecular weight (Mw) and applied to dope and disperse polyaniline (PANI). The structural effect of lignin from different origins on the reactivities of sulfomethylation and HRP polymerization was investigated. The results show that WAL with less methoxyl groups and lower Mw have higher reactivity in sulfomethylation (SWAL). More phenolic hydroxyl groups and lower Mw benefit the HRP polymerization of sulfomethylated PAL (SPAL). Due to the natural three-dimensional aromatic structure and introduced sulfonic groups, SPAL and SWAL could effectively dope and disperse PANI in water by π-π stacking and electrostatic interaction. HRP modified SPAL (HRP-SPAL) with much higher sulfonation degree and larger Mw significantly increased the conductivity and dispersibility of lignin/PANI composites.

Effects of low-level radioactive soil contamination and sterilization on the degradation of radiolabeled wheat straw.

PubMed

Niedrée, Bastian; Vereecken, Harry; Burauel, Peter

2012-07-01

After the explosion of reactor 4 in the nuclear power plant near Chernobyl, huge agricultural areas became contaminated with radionuclides. In this study, we want to elucidate whether (137)Cs and (90)Sr affect microorganisms and their community structure and functions in agricultural soil. For this purpose, the mineralization of radiolabeled wheat straw was examined in lab-scale microcosms. Native soils and autoclaved and reinoculated soils were incubated for 70 days at 20 °C. After incubation, the microbial community structure was compared via 16S and 18S rDNA denaturing gradient gel electrophoresis (DGGE). The radioactive contamination with (137)Cs and (90)Sr was found to have little effect on community structure and no effect on the straw mineralization. The autoclaving and reinoculation of soil had a strong influence on the mineralization and the community structure. Additionally we analyzed the effect of soil treatment on mineralization and community composition. It can be concluded that other environmental factors (such as changing content of dissolved organic carbon) are much stronger regulating factors in the mineralization of wheat straw and that low-level radiation only plays a minor role. Copyright © 2011 Elsevier Ltd. All rights reserved.

Influence of tillage practices and straw incorporation on soil aggregates, organic carbon, and crop yields in a rice-wheat rotation system

PubMed Central

Song, Ke; Yang, Jianjun; Xue, Yong; Lv, Weiguang; Zheng, Xianqing; Pan, Jianjun

2016-01-01

In this study, a fixed-site field experiment was conducted to study the influence of different combinations of tillage and straw incorporation management on carbon storage in different-sized soil aggregates and on crop yield after three years of rice-wheat rotation. Compared to conventional tillage, the percentages of >2 mm macroaggregates and water-stable macroaggregates in rice-wheat double-conservation tillage (zero-tillage and straw incorporation) were increased 17.22% and 36.38% in the 0–15 cm soil layer and 28.93% and 66.34% in the 15–30 cm soil layer, respectively. Zero tillage and straw incorporation also increased the mean weight diameter and stability of the soil aggregates. In surface soil (0–15 cm), the maximum proportion of total aggregated carbon was retained with 0.25–0.106 mm aggregates, and rice-wheat double-conservation tillage had the greatest ability to hold the organic carbon (33.64 g kg−1). However, different forms occurred at higher levels in the 15–30 cm soil layer under the conventional tillage. In terms of crop yield, the rice grown under conventional tillage and the wheat under zero tillage showed improved equivalent rice yields of 8.77% and 6.17% compared to rice-wheat double-cropping under zero tillage or conventional tillage, respectively. PMID:27812038

Direct microbial conversion of wheat straw into lipid by a cellulolytic fungus of Aspergillus oryzae A-4 in solid-state fermentation.

PubMed

Lin, Hui; Cheng, Wan; Ding, Hai-tao; Chen, Xue-jiao; Zhou, Qi-fa; Zhao, Yu-hua

2010-10-01

Direct microbial conversion of wheat straw into lipid by a cellulolytic fungus of Aspergillus oryzae A-4 in solid-state fermentation (SSF) was investigated. In submerged fermentation, A. oryzae A-4 accumulated lipid to 15-18.15% of biomass when pure cellulose was utilized as the sole substrate. In SSF of the wheat straw and bran mixture, A. oryzae A-4 yielded lipid of 36.6mg/g dry substrate (gds), and a cellulase activity of 1.82 FPU/gds with 25.25% of holocellulose utilization in the substrates were detected on the 6th day. The lipid yield reached 62.87 mg/gds in SSF on the 6th day under the optimized conditions from Plackett-Burman design (PBD). Cellulase secretion of A. oryzae A-4 was found to influence the lipid yield. Dilute acid pretreatment of the straw and addition of some agro-industrial wastes to the straw could enhance lipid production of A. oryzae A-4. Copyright 2010 Elsevier Ltd. All rights reserved.

Rapid Assessment of In Situ Wheat Straw Residue Via Remote Sensing Platforms

NASA Technical Reports Server (NTRS)

Sullivan, D. G.; Shaw, J. N.; Mask, P. L.; Rickman, D.; Luvall, J.; Wersinger, J. M.; Guertal, E. A.

2003-01-01

Crop residues influence near surface soil organic carbon content (SOC), impact our ability to remotely assess soil properties, and play a role in global carbon budgets. Methods that measure crop residues are laborious, and largely inappropriate for regional estimates. The objective of this study was to evaluate remote sensing (RS) data for rapid quantification of residue cover. In March 2000 and April 2001, residue plots (15 m x 15 m) were established in the Coastal Plain and Appalachian Plateau physiographic regions of Alabama. Treatments consisted of five wheat (Triticum aestivum L.) straw cover rates (0, 10, 20, 50, and 80%) replicated 3 times. Soil water content and residue decomposition were monitored. Spectral measurements were acquired via spectroradiometer (350 - 1050 nm), Airborne Terrestrial Applications Sensor (ATLAS) (400 - 12,500 nm), airborne color photography (400 - 600 nm), and IKONOS satellite (450 - 900 nm). Spectroradiometer data were acquired monthly, aircraft images yearly, and satellite per availability. Results showed all platforms successfully estimated residue cover variability using red, near infrared (NIR) and thermal infrared (TIR) regions of the spectrum. Airborne ATLAS imagery was best explaining as much as 98% of the variability in wheat straw cover. Spectroradiometer, color infrared photography, and IKONOS imagery accounted for 84, 56, and 24% of the variability, respectively.

Synthesis of wheat straw cellulose-g-poly (potassium acrylate)/PVA semi-IPNs superabsorbent resin.

PubMed

Liu, Jia; Li, Qian; Su, Yuan; Yue, Qinyan; Gao, Baoyu; Wang, Rui

2013-04-15

To better use wheat straw and minimize its negative impact on environment, a novel semi-interpenetrating polymer networks (semi-IPNs) superabsorbent resin (SAR) composed of wheat straw cellulose-g-poly (potassium acrylate) (WSC-g-PKA) network and linear polyvinyl alcohol (PVA) was prepared by polymerization in the presence of a redox initiating system. The structure and morphology of semi-IPNs SAR were characterized by means of FTIR, SEM and TGA, which confirmed that WSC and PVA participated in the graft polymerization reaction with acrylic acid (AA). The factors that can influence the water absorption of the semi-IPNs SAR were investigated and optimized, including the weight ratios of AA to WSC and PVA to WSC, the content of initiator and crosslinker, neutralization degree (ND) of AA, reaction temperature and time. The semi-IPNs SAR prepared under optimized synthesis condition gave the best water absorption of 266.82 g/g in distilled water and 34.32 g/g in 0.9 wt% NaCl solution. Copyright © 2013 Elsevier Ltd. All rights reserved.

Wheat straw biochar-supported nanoscale zerovalent iron for removal of trichloroethylene from groundwater.

PubMed

Li, Hui; Chen, Ya Qin; Chen, Shuai; Wang, Xiao Li; Guo, Shu; Qiu, Yue Feng; Liu, Yong Di; Duan, Xiao Li; Yu, Yun Jiang

2017-01-01

This study synthesized the wheat straw biochar-supported nanoscale zerovalent iron (BC-nZVI) via in-situ reduction with NaBH4 and biochar pyrolyzed at 600°C. Wheat straw biochar, as a carrier, significantly enhanced the removal of trichloroethylene (TCE) by nZVI. The pseudo-first-order rate constant of TCE removal by BC-nZVI (1.079 h-1) within 260 min was 1.4 times higher and 539.5 times higher than that of biochar and nZVI, respectively. TCE was 79% dechlorinated by BC-nZVI within 15 h, but only 11% dechlorinated by unsupported nZVI, and no TCE dechlorination occurred with unmodified biochar. Weakly acidic solution (pH 5.7-6.8) significantly enhanced the dechlorination of TCE. Chloride enhanced the removal of TCE, while SO42-, HCO3- and NO3- all inhibited it. Humic acid (HA) inhibited BC-nZVI reactivity, but the inhibition decreased slightly as the concentration of HA increased from 40 mg∙L-1 to 80 mg∙L-1, which was due to the electron shutting by HA aggregates. Results suggest that BC-nZVI was promising for remediation of TCE contaminated groundwater.

Significance of Herbaspirillum seropedicae inoculation and/or straw amendment on growth and dinitrogen fixation of wheat using 15N-dilution method.

PubMed

el-Komy, H M; Saad, O A; Hetta, A M

2003-01-01

The effect of Herbaspirillum seropedicae inoculation and/or maize straw (0, 5 and 10 Mg/hm2) amendment on the growth and N2 fixation of wheat was determined in pot experiments using 15N-dilution method. Inoculation resulted in accumulation of fixed nitrogen, and % N from atmosphere being 24.6 and 26.5% in wheat shoot and grain, respectively. Straw amendment reduced % Natm to 16.1 and 20.2% at high straw level (10 Mg/hm2). Rational nitrogen fertilization (180 kg N/hm2) completely inhibited N2 fixation by H. seropedicae inoculation. Bacterial inoculation increased dry shoot and grain yield up to 23 and 31%, respectively. The highest levels of shoot and grain dry mass (46.5 and 42.4%) were obtained by N-fertilization in both inoculated and uninoculated plants. Total shoot and grain N-yield increased irrespective of organic matter amendment by inoculation up to 9 and 25%, respectively. N-fertilized plants recorded a maximum increase in N-yield (57 and 51%). H. seropedicae was reisolated from inoculated wheat histosphere after harvesting (90 d from sowing). Neither organic matter nor mineral nitrogen applications had any marked effect on bacterial total counts colonizing wheat histosphere. Moreover, no symptoms of mottled stripe disease were observed on leaves and stems of inoculated plants.

Enhancing Nutritional Contents of Lentinus sajor-caju Using Residual Biogas Slurry Waste of Detoxified Mahua Cake Mixed with Wheat Straw

PubMed Central

Gupta, Aditi; Sharma, Satyawati; Kumar, Ashwani; Alam, Pravej; Ahmad, Parvaiz

2016-01-01

Residual biogas slurries (BGS) of detoxified mahua cake and cow dung were used as supplements to enhance the yield and nutritional quality of Lentinus sajor-caju on wheat straw (WS). Supplementation with 20% BGS gave a maximum yield of 1155 gkg-1 fruit bodies, furnishing an increase of 95.1% over WS control. Significant increase (p ≤ 0.05) in protein content (29.6-38.9%), sugars (29.1-32.3%) and minerals (N, P, K, Fe, Zn) was observed in the fruit bodies. Principle component analysis (PCA) was performed to see the pattern of correlation within a set of observed variables and how these different variables varied in different treatments. PC1 and PC2 represented 90% of total variation in the observed variables. Moisture (%), lignin (%), celluloses (%), and C/N ratio were closely correlated in comparison to Fe, N, and saponins. PCA of amino acids revealed that, PC1 and PC2 represented 74% of total variation in the data set. HPLC confirmed the absence of any saponin residues (characteristic toxins of mahua cake) in fruit bodies and mushroom spent. FTIR studies showed significant degradation of celluloses (22.2-32.4%), hemicelluloses (14.1-23.1%) and lignin (27.4-39.23%) in the spent, along with an increase in nutrition content. The study provided a simple, cost effective approach to improve the yield and nutritional quality of L. sajor-caju by resourceful utilization of BGS. PMID:27790187

Bleach boosting effect of xylanase A from Bacillus halodurans C-125 in ECF bleaching of wheat straw pulp.

PubMed

Lin, Xiao-qiong; Han, Shuang-yan; Zhang, Na; Hu, Hui; Zheng, Sui-ping; Ye, Yan-rui; Lin, Ying

2013-02-05

Past studies have revealed major difficulties in applications of xylanase in the pulp and paper industry as enzymes isolated from many different species could not tolerate high temperatures or highly alkaline conditions. The thermostable xylanase A from Bacillus halodurans C-125 (C-125 xylanase A) was successfully cloned and expressed in Pichia pastoris with a yield as high as 3361 U/mL in a 2 L reactor. Its thermophilic and basophilic properties (optimal activity at 70 °C and pH 9.0), together with the fact it is cellulase-free, render this enzyme attractive for compatible applications in the pulp and paper industry. The pretreatment of wheat straw pulp with C-125 xylanase A at pH 9.0 and 70 °C for 90 min induced the release of both chromophores (Ab(237), Ab(254), Ab(280)) and hydrophobic compounds (Ab(465)) into the filtrate as well as sugar degradation. Moreover, the addition of 10 U xylanase to 1 g wheat straw pulp (dry weight) as pretreatment improved brightness by 5.2% ISO and decreased the kappa number by 5.0% when followed by hydrogen peroxide bleaching. In addition, compared with two commercial enzymes, Pulpzyme HC and AU-PE89, which are normally incorporated in ECF bleaching of wheat straw pulp, C-125 xylanase A proved to be more effective in enhancing brightness as well as preserving paper strength properties. When evaluating the physical properties of pulp samples, such as tensile index, tearing index, bursting index, and post-color (PC) number, the enzymes involved in pretreating pulps exhibited better or the same performances as chemical treatment. Compared with chemical bleaching, chlorine consumption can be significantly reduced by 10% for xylanase-pretreated wheat straw pulp while maintaining the brightness together with the kappa number at the same level. Scanning electron microscopy revealed significant surface modification of enzyme-pretreated pulp fibers with no marked fiber disruptions. Copyright © 2012 Elsevier Inc. All rights reserved.

[The influence of straw, particularly rice straw, together with calcium-cyanamide on the microbiological activity of two Portuguese soils (author's transl)].

PubMed

Glathe, H; El Din, A; Scheuer, A

1976-01-01

The influence of calcium-cyanamide upon the microbiological activity was tested in pot experiments under controlled conditions in two Portuguese soils (sandy and loamy) after the addition of rice or wheat straw (rice straw 0.275% N, wheat straw 0.307% N). The amount of straw was equalled to 100 dz/ha, the application of calcium-cyanamide to 25, 50 and 100 kg N/ha. In the containers treated with straw the total amount of microorganisms (Koch-method) was higher in sandy than in loamy soil after 30 days, but after 70 days it was higher in loamy soil. The content of active nitrogen (NH4 + NO3) increased, when calcium-cyanamide was added, but decreased after the application of straw. After 70 days sandy soil again showed an increase of active nitrogen. Straw increased the rates of CO2-production considerably, wheat straw was superior to rice straw. Calcium-cyanamide increased the CO2-production more in sandy than in loamy soil or German loess, which was also used for this experiment. Only in the case of rice straw higher doses of calcium-cyanamide had a positive effect. After 70 days the CO2-production rose only when rice straw was applied. The dehydrogenase-activity was increased in both soils, but a superiority of wheat straw occurred in sandy soil only. The microbiological activity in the pots with straw was higher in sandy than in loamy soil, the addition of calcium-cyanamide accelerated it. Doses of 25-50 kg N/ha are sufficient generally. The period of the formation of insoluble organic N-compounds, usually connected with the application of organic matter with a wide N:C-ratio, seems to be reduced by the addition of calcium-cyanamide.

Post-harvest processing methods for reduction of silica and alkali metals in wheat straw.

PubMed

Thompson, David N; Shaw, Peter G; Lacey, Jeffrey A

2003-01-01

Silica and alkali metals in wheat straw limit its use for bioenergy and gasification. Slag deposits occur via the eutectic melting of SiO2 with K2O, trapping chlorides at surfaces and causing corrosion. A minimum melting point of 950 degrees C is desirable, corresponding to an SiO2:K2O weight ratio of about 3:1. Mild chemical treatments were used to reduce Si, K, and Cl, while varying temperature, concentration, % solids, and time. Dilute acid was more effective at removing K and Cl, while dilute alkali was more effective for Si. Reduction of minerals in this manner may prove economical for increasing utilization of the straw for combustion or gasification.

Interactions of Kraft lignin and wheat gluten during biomaterial processing: evidence for the role of phenolic groups.

PubMed

Kaewtatip, Kaewta; Menut, Paul; Auvergne, Remi; Tanrattanakul, Varaporn; Morel, Marie-Helene; Guilbert, Stephane

2010-04-14

The chemical interactions between Kraft lignin and wheat gluten under processing conditions were investigated by determining the extent of the protein network formation. To clarify the role of different chemical functions found in lignin, the effect of Kraft lignin was compared with that of an esterified lignin, in which hydroxyl groups had been suppressed by esterification, and with a series of simple aromatics and phenolic structures with different functionalities (conjugated double bonds, hydroxyl, carboxylic acid, and aldehyde). The protein solubility was determined by using the Kjeldahl method. The role of the hydroxyl function was assessed by the significantly lower effect of esterified lignin. The importance of the phenolic radical scavenging structure is evidenced by the effect of guaiacol, which results in a behavior similar to that of the Kraft lignin. In addition, the significant effect of conjugated double bonds on gluten reactivity, through nucleophilic addition, was demonstrated.

Wheat straw biochar-supported nanoscale zerovalent iron for removal of trichloroethylene from groundwater

PubMed Central

Li, Hui; Chen, Ya Qin; Chen, Shuai; Wang, Xiao Li; Guo, Shu; Qiu, Yue Feng; Liu, Yong Di; Duan, Xiao Li; Yu, Yun Jiang

2017-01-01

This study synthesized the wheat straw biochar-supported nanoscale zerovalent iron (BC-nZVI) via in-situ reduction with NaBH4 and biochar pyrolyzed at 600°C. Wheat straw biochar, as a carrier, significantly enhanced the removal of trichloroethylene (TCE) by nZVI. The pseudo-first-order rate constant of TCE removal by BC-nZVI (1.079 h−1) within 260 min was 1.4 times higher and 539.5 times higher than that of biochar and nZVI, respectively. TCE was 79% dechlorinated by BC-nZVI within 15 h, but only 11% dechlorinated by unsupported nZVI, and no TCE dechlorination occurred with unmodified biochar. Weakly acidic solution (pH 5.7–6.8) significantly enhanced the dechlorination of TCE. Chloride enhanced the removal of TCE, while SO42−, HCO3− and NO3− all inhibited it. Humic acid (HA) inhibited BC-nZVI reactivity, but the inhibition decreased slightly as the concentration of HA increased from 40 mg∙L-1 to 80 mg∙L-1, which was due to the electron shutting by HA aggregates. Results suggest that BC-nZVI was promising for remediation of TCE contaminated groundwater. PMID:28264061

Enzymatic hydrolysis optimization of microwave alkali pretreated wheat straw and ethanol production by yeast.

PubMed

Singh, Anita; Bishnoi, Narsi R

2012-03-01

Microwave alkali pretreated wheat straw was used for in-house enzyme production by Aspergillusflavus and Trichodermareesei. Produced enzymes were concentrated, pooled and assessed for the hydrolysis of pretreated wheat straw. Factors affecting hydrolysis were screened out by Placket-Burman design (PBD) and most significant factors were further optimized by Box-Behnken design (BBD). Under optimum conditions, 82% efficiency in hydrolysis yield was observed. After the optimization by response surface methodology (RSM), a model was proposed to predict the optimum value confirmed by the experimental results. The concentrated enzymatic hydrolyzate was fermented for ethanol production by Saccharomyces cerevisiae, Pichia stipitis and co-culture of both. The yield of ethanol was found to be 0.48 g(p)/g(s), 0.43 g(p)/g(s) and 0.40 g(p)/g(s) by S. cerevisiae, P. stipitis and by co-culture, respectively, using concentrated enzymatic hydrolyzate. During anaerobic fermentation 42.31 μmol/mL, 36.69 μmol/mL, 43.35 μmol/mL CO(2) was released by S. cerevisiae, P. stipitis and by co-culture, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

Improvement of yield of the edible and medicinal mushroom Lentinula edodes on wheat straw by use of supplemented spawn

PubMed Central

Gaitán-Hernández, Rigoberto; Cortés, Norberto; Mata, Gerardo

2014-01-01

The research evaluated the interactions of two main factors (strain / types of spawn) on various parameters with the purpose to assess its effect on yield and biochemical composition of Lentinula edodes fruiting bodies cultivated on pasteurized wheat straw. The evaluation was made with four strains (IE-40, IE-105, IE-124 and IE-256). Different types of spawns were prepared: Control (C) (millet seed, 100%), F1 (millet seed, 88.5%; wheat bran, 8.8%; peat moss, 1.3%; and CaS04, 1.3%) and F2 (the same formula as F1, but substituting the wheat bran with powdered wheat straw). Wheat straw was pasteurized by soaking it for 1 h in water heated to 65 °C. After this the substrate (2 kg wet weight) was placed in polypropylene bags. The bags were inoculated with each spawn (5% w/w) and incubated in a dark room at 25 °C. A proximate analysis of mature fruiting bodies was conducted. The mean Biological Efficiency (BE) varied between 66.0% (C-IE-256) and 320.1% (F1-IE-124), with an average per strain of 125.6%. The highest mean BE was observed on spawn F1 (188.3%), significantly different from C and F2. The protein content of fruiting bodies was high, particularly in strain IE-40-F1 (17.7%). The amount of fat varied from 1.1 (F1-IE-40) to 2.1% (F2-IE-105) on dry matter. Carbohydrates ranged from 58.8% (F1-IE-40) to 66.1% (F1-IE-256). The energy value determined ranged from 302.9 kcal (F1-IE-40) to 332.0 kcal (F1-IE-256). The variability on BE observed in this study was significantly influenced by the spawn’s formulation and genetic factors of the different strains. PMID:25242929

Amino acid production from rice straw and wheat bran hydrolysates by recombinant pentose-utilizing Corynebacterium glutamicum.

PubMed

Gopinath, Vipin; Meiswinkel, Tobias M; Wendisch, Volker F; Nampoothiri, K Madhavan

2011-12-01

Corynebacterium glutamicum wild type lacks the ability to utilize the pentose fractions of lignocellulosic hydrolysates, but it is known that recombinants expressing the araBAD operon and/or the xylA gene from Escherichia coli are able to grow with the pentoses xylose and arabinose as sole carbon sources. Recombinant pentose-utilizing strains derived from C. glutamicum wild type or from the L-lysine-producing C. glutamicum strain DM1729 utilized arabinose and/or xylose when these were added as pure chemicals to glucose-based minimal medium or when they were present in acid hydrolysates of rice straw or wheat bran. The recombinants grew to higher biomass concentrations and produced more L-glutamate and L-lysine, respectively, than the empty vector control strains, which utilized the glucose fraction. Typically, arabinose and xylose were co-utilized by the recombinant strains along with glucose either when acid rice straw and wheat bran hydrolysates were used or when blends of pure arabinose, xylose, and glucose were used. With acid hydrolysates growth, amino acid production and sugar consumption were delayed and slower as compared to media with blends of pure arabinose, xylose, and glucose. The ethambutol-triggered production of up to 93 ± 4 mM L-glutamate by the wild type-derived pentose-utilizing recombinant and the production of up to 42 ± 2 mM L-lysine by the recombinant pentose-utilizing lysine producer on media containing acid rice straw or wheat bran hydrolysate as carbon and energy source revealed that acid hydrolysates of agricultural waste materials may provide an alternative feedstock for large-scale amino acid production.

Isolation of a rice endophytic bacterium, Pantoea sp. Sd-1, with ligninolytic activity and characterization of its rice straw degradation ability.

PubMed

Xiong, X Q; Liao, H D; Ma, J S; Liu, X M; Zhang, L Y; Shi, X W; Yang, X L; Lu, X N; Zhu, Y H

2014-02-01

This study focused on an endophytic bacterial strain, Pantoea sp. Sd-1, which can be used to degrade lignin and rice straw. This strain was isolated from rice seeds by an optimized surface sterilization method. Pantoea sp. Sd-1 showed exceptional ability to degrade rice straw and lignin. In rice straw or kraft lignin-containing medium supplemented with 1% glucose and 0.5% peptone, Pantoea sp. Sd-1 effectively reduced the rice straw mass weight by 54.5% after 6 days of treatment. The strain was also capable of reducing the lignin colour (52.4%) and content (69.1%) after 4 days of incubation. The findings suggested that the rice endophytic bacterium Pantoea sp. Sd-1 could be applied for the degradation of lignocellulose biomass, such as rice straw. Rice straw, an abundant agricultural by-product in China, is very difficult to degrade because of its high lignin content. Due to the immense environmental adaptability and biochemical versatility of bacteria, endophytic bacteria are useful resources for biodegradation. In this study, we screened for endophytic bacteria capable of biodegrading rice straw and lignin and obtained one strain, Pantoea sp. Sd-1, with suitable characteristics. Sd-1 could be used for degradation of rice straw and lignin, and may play an important role in biodegradation of this agricultural by-product. © 2013 The Society for Applied Microbiology.

[Comparing the ammonia volatilization characteristic of two typical paddy soil with total wheat straw returning in Taihu Lake region].

PubMed

Wang, Jun; Wang, De-Jian; Zhang, Gang; Wang, Yuan

2013-01-01

An experiment using monolith lysimeter was conducted to compare the characteristic of N loss by ammonia (NH3) volatilization between the gleyed paddy soil (G soil) and hydromorphic paddy soil (H soil) the Changshu National Agro-ecological Experimental Station of the Chinese Academy of Sciences(31 degrees 33' N, 123 degrees 38' E). Three treatments were designed for each soil type, i. e. control (no urea and straw applied), nitrogen solely and nitrogen plus wheat straw. Ammonia volatilization, flood water NH4(+) -N concentration, pH and top soil Eh were measured during the rice-growing season. Results showed that the NH3 volatilization flux and cumulative N losses by NH3 volatilization from G soil were significantly higher than those from H soil, the average cumulative N losses being about 41.8 kg x hm(-2) and 11.2 kg x hm(-2), or 15.2% and 3.8% of the fertilizer N, respectively. The average N loss by NH3 volatilization during the tillering stage was the highest among the three fertilization stages, accounting for 29.4% and 8.3% of the fertilizer N for G soil and H soil, respectively. Wheat straw returning significantly increased paddy filed NH3 volatilization losses. Comparing with the sole application of fertilizer-N, the cumulative N loss by NH3 volatilization of fertilizer-N in combination with wheat straw was increased by 19.8% and 20.6% for G soil and H soil, respectively. In addition, ammonia volatilization fluxes showed a positive relationship with the flood water NH4(+) -N concentration and pH for both soils, but the relationship with top soil Eh still needs further study.

Changes in Lignin and Polysaccharide Components in 13 Cultivars of Rice Straw following Dilute Acid Pretreatment as Studied by Solution-State 2D 1H-13C NMR

PubMed Central

Teramura, Hiroshi; Sasaki, Kengo; Oshima, Tomoko; Aikawa, Shimpei; Matsuda, Fumio; Okamoto, Mami; Shirai, Tomokazu; Kawaguchi, Hideo; Ogino, Chiaki; Yamasaki, Masanori; Kikuchi, Jun; Kondo, Akihiko

2015-01-01

A renewable raw material, rice straw is pretreated for biorefinery usage. Solution-state two-dimensional (2D) 1H-13 C hetero-nuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) spectroscopy, was used to analyze 13 cultivars of rice straw before and after dilute acid pretreatment, to characterize general changes in the lignin and polysaccharide components. Intensities of most (15 of 16) peaks related to lignin aromatic regions, such as p-coumarate, guaiacyl, syringyl, p-hydroxyphenyl, and cinnamyl alcohol, and methoxyl, increased or remained unchanged after pretreatment. In contrast, intensities of most (11 of 13) peaks related to lignin aliphatic linkages or ferulate decreased. Decreased heterogeneity in the intensities of three peaks related to cellulose components in acid-insoluble residues resulted in similar glucose yield (0.45–0.59 g/g-dry biomass). Starch-derived components showed positive correlations (r = 0.71 to 0.96) with glucose, 5-hydroxymethylfurfural (5-HMF), and formate concentrations in the liquid hydrolysates, and negative correlations (r = –0.95 to –0.97) with xylose concentration and acid-insoluble residue yield. These results showed the fate of lignin and polysaccharide components by pretreatment, suggesting that lignin aromatic regions and cellulose components were retained in the acid insoluble residues and starch-derived components were transformed into glucose, 5-HMF, and formate in the liquid hydrolysate. PMID:26083431

Environmental performance of straw-based pulp making: A life cycle perspective.

PubMed

Sun, Mingxing; Wang, Yutao; Shi, Lei

2018-03-01

Agricultural straw-based pulp making plays a vital role in pulp and paper industry, especially in forest deficient countries such as China. However, the environmental performance of straw-based pulp has scarcely been studied. A life cycle assessment on wheat straw-based pulp making in China was conducted to fill of the gaps in comprehensive environmental assessments of agricultural straw-based pulp making. On average, the global warming potential (GWP), GWP excluding biogenic carbon, acidification potential and eutrophication potential of wheat straw based pulp making are 2299kg CO 2 -eq, 4550kg CO 2 -eq, 16.43kg SO 2 -eq and 2.56kg Phosphate-eq respectively. The dominant factors contributing to environmental impacts are coal consumption, electricity consumption, and chemical (NaOH, ClO 2 ) input. Chemical input decrease and energy recovery increase reduce the total environmental impacts dramatically. Compared with wood-based and recycled pulp making, wheat straw-based pulp making has higher environmental impacts, which are mainly due to higher energy and chemical requirements. However, the environmental impacts of wheat straw-based pulp making are lower than hemp and flax based pulp making from previous studies. It is also noteworthy that biogenic carbon emission is significant in bio industries. If carbon sequestration is taken into account in pulp making industry, wheat straw-based pulp making is a net emitter rather than a net absorber of carbon dioxide. Since wheat straw-based pulp making provides an alternative for agricultural residue management, its evaluation framework should be expanded to further reveal its environmental benefits. Copyright © 2017 Elsevier B.V. All rights reserved.

Effect of Additions on Ensiling and Microbial Community of Senesced Wheat Straw

DOE Office of Scientific and Technical Information (OSTI.GOV)

David N. Thompson; Joni M. Barnes; Tracy P. Houghton

2005-04-01

Crop residues collected during or after grain harvest are available once per year and must be stored for extended periods. The combination of air, high moisture, and high microbial loads leads to shrinkage during storage and risk of spontaneous ignition. Ensiling is a wet preservation method that could be used to store these residues stably. To economically adapt ensiling to biomass that is harvested after it has senesced, the need for nutrient, moisture, and microbial additions must be determined. We tested the ensiling of senesced wheat straw in sealed columns for 83 d. The straw was inoculated with Lactobacillus plantarummore » and amended with several levels of water and free sugars. The ability to stabilize the straw polysaccharides was strongly influenced by both moisture and free sugars. Without the addition of sugar, the pH increased from 5.2 to as much as 9.1, depending on moisture level, and losses of 22% of the cellulose and 21% of the hemicellulose were observed. By contrast, when sufficient sugars were added and interstitial water was maintained, a final pH of 4.0 was attainable, with correspondingly low (<5%) losses of cellulose and hemicellulose. The results show that ensiling should be considered a promising method for stable storage of wet biorefinery feedstocks.« less

Molecular composition and size distribution of sugars, sugar-alcohols and carboxylic acids in airborne particles during a severe urban haze event caused by wheat straw burning

NASA Astrophysics Data System (ADS)

Wang, Gehui; Chen, Chunlei; Li, Jianjun; Zhou, Bianhong; Xie, Mingjie; Hu, Shuyuan; Kawamura, Kimitaka; Chen, Yan

2011-05-01

Molecular compositions and size distributions of water-soluble organic compounds (WSOC, i.e., sugars, sugar-alcohols and carboxylic acids) in particles from urban air of Nanjing, China during a severe haze event caused by field burning of wheat straw were characterized and compared with those in the summer and autumn non-haze periods. During the haze event levoglucosan (4030 ng m -3) was the most abundant compound among the measured WSOC, followed by succinic acid, malic acid, glycerol, arabitol and glucose, being different from those in the non-haze samples, in which sucrose or azelaic acid showed a second highest concentration, although levoglucosan was the highest. The measured WSOC in the haze event were 2-20 times more than those in the non-hazy days. Size distribution results showed that there was no significant change in the compound peaks in coarse mode (>2.1 μm) with respect to the haze and non-haze samples, but a large difference in the fine fraction (<2.1 μm) was found with a sharp increase during the hazy days mostly due to the increased emissions of wheat straw burning. Molecular compositions of organic compounds in the fresh smoke particles from wheat straw burning demonstrate that sharply increased concentrations of glycerol and succinic and malic acids in the fine particles during the haze event were mainly derived from the field burning of wheat straw, although the sources of glucose and related sugar-alcohols whose concentrations significantly increased in the fine haze samples are unclear. Compared to that in the fresh smoke particles of wheat straw burning an increase in relative abundance of succinic acid to levoglucosan during the haze event suggests a significant production of secondary organic aerosols during transport of the smoke plumes.

A new pulping process for wheat straw to reduce problems with the discharge of black liquor.

PubMed

Huang, Guolin; Shi, Jeffrey X; Langrish, Tim A G

2007-11-01

Aqueous ammonia mixed with caustic potash as wheat straw pulping liquor was investigated. The caustic potash did not only reduce the NH3 usage and cooking time, but also provided a potassium source as a fertilizer in the black liquor. Excess NH3 in the black liquor was recovered and reused by batch distillation with a 98% recovery rate of free NH3. The black liquor was further treated for reuse by coagulation under alkaline conditions. The effects of different flocculation conditions, such as the dosage of 10% aluminium polychloride, the dosage of 0.1% polyacrylamide, the reaction temperature and the pH of the black liquor on the flocculating process were studied. The supernatant was recycled as cooking liquor by adding extra NH4OH and KOH. The amount of delignification and the pulp yield for the process remained steady at 82-85% and 48-50%, respectively, when reusing the supernatant four times. The coagulated residues could be further processed as solid fertilizers. This study provided a new pulping process for wheat straw to reduce problems of discharge black liquor.

Greenhouse gas emissions and reactive nitrogen releases from rice production with simultaneous incorporation of wheat straw and nitrogen fertilizer

NASA Astrophysics Data System (ADS)

Xia, Longlong; Xia, Yongqiu; Ma, Shutan; Wang, Jinyang; Wang, Shuwei; Zhou, Wei; Yan, Xiaoyuan

2016-08-01

Impacts of simultaneous inputs of crop straw and nitrogen (N) fertilizer on greenhouse gas (GHG) emissions and N losses from rice production are not well understood. A 2-year field experiment was established in a rice-wheat cropping system in the Taihu Lake region (TLR) of China to evaluate the GHG intensity (GHGI) as well as reactive N intensity (NrI) of rice production with inputs of wheat straw and N fertilizer. The field experiment included five treatments of different N fertilization rates for rice production: 0 (RN0), 120 (RN120), 180 (RN180), 240 (RN240), and 300 kg N ha-1 (RN300, traditional N application rate in the TLR). Wheat straws were fully incorporated into soil before rice transplantation. The meta-analytic technique was employed to evaluate various Nr losses. Results showed that the response of rice yield to N rate successfully fitted a quadratic model, while N fertilization promoted Nr discharges exponentially (nitrous oxide emission, N leaching, and runoff) or linearly (ammonia volatilization). The GHGI of rice production ranged from 1.20 (RN240) to 1.61 kg CO2 equivalent (CO2 eq) kg-1 (RN0), while NrI varied from 2.14 (RN0) to 10.92 g N kg-1 (RN300). Methane (CH4) emission dominated the GHGI with a proportion of 70.2-88.6 % due to direct straw incorporation, while ammonia (NH3) volatilization dominated the NrI with proportion of 53.5-57.4 %. Damage costs to environment incurred by GHG and Nr releases from current rice production (RN300) accounted for 8.8 and 4.9 % of farmers' incomes, respectively. Cutting N application rate from 300 (traditional N rate) to 240 kg N ha-1 could improve rice yield and nitrogen use efficiency by 2.14 and 10.30 %, respectively, while simultaneously reducing GHGI by 13 %, NrI by 23 %, and total environmental costs by 16 %. Moreover, the reduction of 60 kg N ha-1 improved farmers' income by CNY 639 ha-1, which would provide them with an incentive to change the current N application rate. Our study suggests that GHG

Fungal biodegradation and biotransformation of soluble lignocarbohydrate complexes from straw. [Aspergillus japonicus, Polyporus versicolor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milstein, O.A.; Vared, Y.; Sharma, A.

1983-08-01

Aspergillus japonicus is an efficient degrader of phenolics and carbohydrates present in a mixture of soluble lignocarbohydrate complexes extracted from wheat straw. Trichoderma species attacked part of the carbohydrate but hardly affected the aromatic portion of this solution. Polyporus versicolor had a complex effect; polymerization of low-molecular-size phenolics accompanied the degradation of aromatic and carbohydrate polymers. The addition of xylose to the medium facilitated depolymerization of lignin by the fungi tested and prevented the polymerization of low-molecular-size fractions of lignocarbohydrate complexes by P. versicolor. P. versicolor, in contrast to A. japonicus and Trichoderma species, also excreted into the medium considerablemore » amounts of laccase, but only in the absence of endogenous or exogenous carbohydrates. Apparently, laccase is involved in polymerization rather than degradation of lignin in this organism. A number of extracellular glycanases were also secreted by these fungi. 19 references« less

Ozonation and alkaline-peroxide pretreatment of wheat straw for Cryptococcus curvatus fermentation

NASA Technical Reports Server (NTRS)

Greenwalt, C. J.; Hunter, J. B.; Lin, S.; McKenzie, S.; Denvir, A.

2000-01-01

Crop residues in an Advanced Life Support System (ALS) contain many valuable components that could be recovered and used. Wheat is 60% inedible, with approximately 90% of the total sugars in the residue cellulose and hemicellulose. To release these sugars requires pretreatment followed by enzymatic hydrolysis. Cryptococcus curvatus, an oleaginous yeast, uses the sugars in cellulose and hemicellulose for growth and production of storage triglycerides. In this investigation, alkaline-peroxide and ozonation pretreatment methods were compared for their efficiency to release glucose and xylose to be used in the cultivation of C. curvatus. Leaching the biomass with water at 65 degrees C for 4 h prior to pretreatment facilitated saccharification. Alkaline-peroxide and ozone pretreatment were almost 100% and 80% saccharification efficient, respectively. The sugars derived from the hydrolysis of alkaline-peroxide-treated wheat straw supported the growth of C. curvatus and the production of edible single-cell oil.

Effect of long term feeding of ammoniated wheat straw treated with or without HCl on blood biochemical parameters in growing male buffalo (Bubalus bubalis) calves.

PubMed

Mehra, Usha Rani; Sahu, Dev Sharan; Naik, Prafulla Kumar; Dass, Ram Sharan; Verma, Ashok Kumar

2005-01-01

Twenty-four growing male buffalo calves (one year of age; 88.54 +/- 3.81 kg average body weight) were divided into three comparable groups (I, II and III) on the basis of their body weight (BW) in a completely randomised design to study the effect of long term feeding of ammoniated wheat straw (AWS) and hydrochloric acid treated ammoniated wheat straw (HCl-AWS) on blood biochemical changes. The animals were offered a concentrate mixture (CM) along with wheat straw (WS), ammoniated wheat straw (AWS) (4% urea at a 50% moisture level) and hydrochloric acid treated ammoniated wheat straw (HCI-AWS) (4% urea at a 50% moisture level and HCI added to trap 30% of NH3 evolved) in groups I, II and III, respectively for an average daily gain (ADG) of 500 g. All the diets were made iso-nitrogenous by preparing three types of concentrate mixtures of different CP levels. The blood was collected from the jugular vein randomly from three animals of each group initially after 8 months post feeding and subsequently after two months interval up to 14 months of experimental feeding. Due to urea ammoniation, the CP content of WS increased from 3.66 to 8.51 and was further increased to 11.35 due to the addition of HCl during urea-ammoniation of wheat straw. The cumulative period mean plasma glucose values (mg %), in group II (53.13) were significantly (P < 0.001) higher than those in groups I (48.44) and III (50.60). The cumulative period mean values of serum albumin and globulin (g %) were not significantly different and were comparable among the groups I (3.33 and 3.06), II (3.53 and 2.97) and III (3.49 and 2.94). The cumulative period mean values of serum albumin: globulin ratio and total protein values were not significantly different among the different groups. Serum urea and creatinine values were significantly (P < 0.001) higher in group III (58.66 and 2.24) as compared to groups I and II. The cumulative period mean values of serum alkaline phosphatase (ALP) (KA units) did not

An efficient process for lactic acid production from wheat straw by a newly isolated Bacillus coagulans strain IPE22.

PubMed

Zhang, Yuming; Chen, Xiangrong; Luo, Jianquan; Qi, Benkun; Wan, Yinhua

2014-04-01

A thermophilic lactic acid (LA) producer was isolated and identified as Bacillus coagulans strain IPE22. The strain showed remarkable capability to ferment pentose, hexose and cellobiose, and was also resistant to inhibitors from lignocellulosic hydrolysates. Based on the strain's promising features, an efficient process was developed to produce LA from wheat straw. The process consisted of biomass pretreatment by dilute sulfuric acid and subsequent SSCF (simultaneous saccharification and co-fermentation), while the operations of solid-liquid separation and detoxification were avoided. Using this process, 46.12 g LA could be produced from 100g dry wheat straw with a supplement of 10 g/L corn steep liquid powder at the cellulase loading of 20 FPU (filter paper activity units)/g cellulose. The process by B. coagulans IPE22 provides an economical route to produce LA from lignocellulose. Copyright © 2014 Elsevier Ltd. All rights reserved.

Predicting the ethanol potential of wheat straw using near-infrared spectroscopy and chemometrics: The challenge of inherently intercorrelated response functions

DOE PAGES

Rinnan, Asmund; Bruun, Sander; Lindedam, Jane; ...

2017-02-07

Here, the combination of NIR spectroscopy and chemometrics is a powerful correlation method for predicting the chemical constituents in biological matrices, such as the glucose and xylose content of straw. However, difficulties arise when it comes to predicting enzymatic glucose and xylose release potential, which is matrix dependent. Further complications are caused by xylose and glucose release potential being highly intercorrelated. This study emphasizes the importance of understanding the causal relationship between the model and the constituent of interest. It investigates the possibility of using near-infrared spectroscopy to evaluate the ethanol potential of wheat straw by analyzing more than 1000more » samples from different wheat varieties and growth conditions. During the calibration model development, the prime emphasis was to investigate the correlation structure between the two major quality traits for saccharification of wheat straw: glucose and xylose release. The large sample set enabled a versatile and robust calibration model to be developed, showing that the prediction model for xylose release is based on a causal relationship with the NIR spectral data. In contrast, the prediction of glucose release was found to be highly dependent on the intercorrelation with xylose release. If this correlation is broken, the model performance breaks down. A simple method was devised for avoiding this breakdown and can be applied to any large dataset for investigating the causality or lack of causality of a prediction model.« less

Predicting the ethanol potential of wheat straw using near-infrared spectroscopy and chemometrics: The challenge of inherently intercorrelated response functions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rinnan, Asmund; Bruun, Sander; Lindedam, Jane

Here, the combination of NIR spectroscopy and chemometrics is a powerful correlation method for predicting the chemical constituents in biological matrices, such as the glucose and xylose content of straw. However, difficulties arise when it comes to predicting enzymatic glucose and xylose release potential, which is matrix dependent. Further complications are caused by xylose and glucose release potential being highly intercorrelated. This study emphasizes the importance of understanding the causal relationship between the model and the constituent of interest. It investigates the possibility of using near-infrared spectroscopy to evaluate the ethanol potential of wheat straw by analyzing more than 1000more » samples from different wheat varieties and growth conditions. During the calibration model development, the prime emphasis was to investigate the correlation structure between the two major quality traits for saccharification of wheat straw: glucose and xylose release. The large sample set enabled a versatile and robust calibration model to be developed, showing that the prediction model for xylose release is based on a causal relationship with the NIR spectral data. In contrast, the prediction of glucose release was found to be highly dependent on the intercorrelation with xylose release. If this correlation is broken, the model performance breaks down. A simple method was devised for avoiding this breakdown and can be applied to any large dataset for investigating the causality or lack of causality of a prediction model.« less

Growth of Azotobacter vinelandii in a solid-state fermentation of technical lignin.

PubMed

Zhang, Xiaoyong; Zhao, Hua; Zhang, Jianan; Li, Zuohu

2004-10-01

Azotobacter vinelandii was cultured on technical lignin, derived from Kraft pulping processes, for biofertilizer production in solid-state fermentation. The effects of the ratio of technical lignin to corn straw, initial water content, and material bed depth on the microorganisms were studied in detail. At 30 degrees C, technical lignin to corn straw at the ratio of 1:0.75, the bed depth of 5 cm, and 67% moisture content, A. vinelandii was grown and reached 4.2 x 10(10) cfu g(-1) dry rot after 36 h.

Combined bioaugmentation with anaerobic ruminal fungi and fermentative bacteria to enhance biogas production from wheat straw and mushroom spent straw.

PubMed

Ferraro, Alberto; Dottorini, Giulia; Massini, Giulia; Mazzurco Miritana, Valentina; Signorini, Antonella; Lembo, Giuseppe; Fabbricino, Massimiliano

2018-07-01

Bioaugmentation with anaerobic ruminal fungi and a pool of hydrogen-producing fermenting bacteria was tested on wheat straw (WS) and mushroom spent straw (MSS) with the aim of improving anaerobic digestion performance. Batch tests were set up to simulate a Bioaugmentation Anaerobic Digestion (BAD) treatment comparing single- (I-BAD) and two-stage (II-BAD) process configurations, at two reactor scales, 120 and 1200 ml (×10). In both cases, higher CH 4 cumulative production was obtained in the II-BAD configuration on WS (65.1 ± 8.9 Nml and 922 ± 73.8 Nml respectively). The II-BADx10 tests allowed increasing CH 4 production (≃290% and ≃330% on WS and MSS, respectively) when compared to the unaugmented condition. Final results highlighted the achievable advantages of the two stage configuration in terms of CH 4 production enhancement. Microbial community investigations confirmed the efficiency of the bioaugmentation treatment and revealed that such a result was mainly related to the Methanosarcinales increase, mostly composed by Methanosaeta. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Effects of nitrogen application on decomposition and nutrient release of returned maize straw in Guanzhong Plain, Northwest China].

PubMed

Huang, Ting Miao; Wang, Zhao Hui; Hou, Yang Yi; Gu, Chi Ming; Li, Xiao; Zheng, Xian Feng

2017-07-18

With 15 N isotope labeled maize straw in nylon net bags and buried in the wheat field at two N rates of 0 and 200 kg N·hm -2 , the effects of nitrogen application on the decomposition of straw dry matter and the release dynamics of carbon, nitrogen, phosphorus and potassium (C, N, P and K) after maize straw retention were investigated in the winter wheat-summer maize rotation system in Guanzhong Plain, Shaanxi, China. Results showed that N application did not affect the decomposition of the returned straw C and dry matter, but promoted the release of P and inhibited the release of N and K from straw during sowing to wintering periods of winter wheat. From the grain filling to the harvest of winter wheat, the decomposition of the returned straw and the release of N, P and K were not affected, but the release of straw C was significantly enhanced by N application. The release dynamic of straw C was synchronized with the decomposition of the dry matter, and the C/N of straw declined gradually with the extension of wheat growing. Until the harvest of winter wheat, the accumulative decomposition rate of straw dry matter was less than 50%, and the total straw C release rate was around 47.9% to 51.1%. The C/N ratio of the returned straw was decreased from 32.2 to 20.2 and 17.9, respectively at N rates of 0 and 200 kg N·hm -2 . From sowing to harvest of winter wheat, the net release of N, P and K from the straw was observed. The N release was 7.2-9.4 kg·hm -2 and 12.7%-16.6% of the total straw N, and the P release was 1.29-1.44 kg·hm -2 and 29.0%-32.4% of the total straw P, while a great deal of K was released quickly, with approximately 80% of the straw K released before wintering, 51.8-52.5 kg·hm -2 and 90.5%-91.7% of the total straw K released at wheat harvest. It was suggested that the K fertilizer application should be decreased for the winter wheat due to the great amount K release from the returned maize straw, and an extra amount of N and P fertilizer should

A straw-soil co-composting and evaluation for plant substrate in BLSS

NASA Astrophysics Data System (ADS)

Cheng, Quanyong; Guo, Shuangsheng; Ai, Weidang; Tang, Yongkang; Qin, Lifeng

2013-02-01

Material closure is important for the establishment of Bioregenerative Life Support System, and many studies have focused on transforming candidate plant residues into plant culture medium. For the limitations of using wheat straw compost as substrate for plant cultivation, a straw-soil co-composting technique was studied. The changes of pH, C/N value, germination index, cellulose, lignin and so on were monitored during the co-composting process. The maturity was evaluated by the C/N value and the germination index. The result showed that after 45 days' fermentation, the straw-soil final co-compost with inoculation (T1) became mature, while the co-compost without inoculation (T0) was not mature. In the plant culture test, the T1 substrate could satisfy the needs for lettuce's growth, and the edible biomass yield of lettuce averaged 74.42 g pot-1 at harvest. But the lettuces in T0 substrate showed stress symptoms and have not completed the growth cycle. Moreover, the results of nitrogen (N) transformation experiment showed that about 10.0% and 3.1% N were lost during the T1 co-composting and plant cultivation, respectively, 23.5% N was absorbed by lettuce, and 63.4% N remained in the T1 substrate after cultivation.

Process for calcium xylonate production as a concrete admixture derived from in-situ fermentation of wheat straw pre-hydrolysate.

PubMed

Zhou, Xin; Zhou, Xuelian; Tang, Xiusheng; Xu, Yong

2018-08-01

One of the major obstacles in process of lignocellulosic biorefinery is the utilization of pre-hydrolysate from pre-treatment. Although lignocellulosic pre-hydrolysate can serve as an economic starting material for xylonic acid production, the advancement of xylonic acid or xylonate is still limited by further commercial value or applications. In the present study, xylose in the high concentration wheat straw pre-hydrolysate was first in-situ biooxidized to xylonate by Gluconobacter oxydans. To meet the needs of commercialization, crude powdered calcium xylonate was prepared by drying process and calcium xylonate content in the prepared crude product was more than 70%. Then, the calcium xylonate product was evaluated as concrete admixture without any complex purification steps and the results demonstrated that xylonate could improve the performance of concrete. Overall, the crude xylonate product directly produced from low-cost wheat straw pre-hydrolysate can potentially be developed as retarding reducer, which could subsequently benefit lignocellulosic biorefinery. Copyright © 2018 Elsevier Ltd. All rights reserved.

Effect of fertilizer prepared from human feces and straw on germination, growth and development of wheat

NASA Astrophysics Data System (ADS)

Liu, Dianlei; Xie, Beizhen; Dong, Chen; Liu, Guanghui; Hu, Dawei; Qin, Youcai; Li, Hongyan; Liu, Hong

2018-04-01

Solid waste treatment is one of the most important rate-limiting steps in the material circulation and energy flow of Bioregenerative Life Support System (BLSS). In our previous work, an efficient and controllable solid waste bio-convertor has been built and a solid waste degradation efficiency of 41.0% has been reached during a 105-d BLSS experiment. However, the fermented residues should be further utilized to fulfill the closure of the system. One solution might be to use the residues as the fertilizer for plant cultivation. Thus in this study, substrates were prepared using different ratios of the fermented residues to the vermiculite. And the influences of different ratios of the fermented residues on the seed germination, growth, photosynthetic characteristics and antioxidant capacity of wheat were studied. The results showed that the optimal rate of the fermented residue was 5%. With this ratio, the seed germination reached 97.3% with the root length, shoot length and biomass production as 59 mm, 52 mm and 150 mg, respectively, at the 4th day. Besides, the highest straw height of 25.1 cm was obtained at the 21st day. The salinity adversely affected the growth and some relevant metabolic processes of wheat. The Group-40% led to the lowest seed germination of 34.7% and the minimum straw height of 15 cm. This inhibition might be caused by the high Na content of 2118 mg/kg in the fermented residues. Chlorophyll b was more sensitive to the mineral nutrition stress and affects the wheat photosynthetic characteristics. Higher reactive oxygen species levels and reduced antioxidant enzymes may contribute, directly and/or indirectly, to the decline in the observed pigment contents in wheat.

[Experimental investigation of the straw pre-treatment to enhance its high solid anaerobic digestion].

PubMed

Jiang, Jian-Guo; Zhao, Zhen-Zhen; Du, Xue-Juan; Sui, Ji-Chao; Wu, Shi-Yao

2007-04-01

The straw contains a high content of lignin, which cannot be well utilized by anaerobic bacteria in high solid anaerobic digestion process. This paper presents the experimental investigation of the straw pre-treatment, which aims to destroy the complex structure of the lignin to enhance its high solid anaerobic digestion. The straw is pre-treated in different solutions including NaOH, ammonia, H2SO4, and carbamide. The pre-treating effects are expressed by COD concentration dissolved in the solutions and the 14-day biogas generation in the enhanced aerogenic experiment. Different affecting factors, such as the concentration of the chemical solution, the species of the straw, the pre-treatment reaction time, the reaction temperature and the size of the straw, are investigated. The results show that NaOH solution is the most effective pre-treatment chemical among the four different solutions. The experimental results still indicate that the accumulative biogas production can be 1 500 mL (10 g straw) in 14 days after pre-treatment in 4 mg/L NaOH solution and the dissolved COD in the solution reaches 39 000 mg/L after 24 hours. In addition, the experiment shows that the lignin content in the straw is reduced from 28% to 19% after pre-treatment in 1.5% (in weight) NaOH solution, and it can improve the straw treatment efficiency using high solid anaerobic digestion process.

Preparation of wheat straw based superabsorbent resins and their applications as adsorbents for ammonium and phosphate removal.

PubMed

Liu, Jia; Su, Yuan; Li, Qian; Yue, Qinyan; Gao, Baoyu

2013-09-01

A novel wheat straw cellulose-g-poly (potassium acrylate)/polyvinyl alcohol (WSC-g-PKA/PVA) semi-interpenetrating polymer networks (semi-IPNs) superabsorbent resin (SAR) was prepared by graft copolymerization. The structure and performance of the WSC-g-PKA/PVA semi-IPNs SAR was studied and compared with those of wheat straw cellulose-g-poly (potassium acrylate) (WSC-g-PKA) SAR. The effects of various experimental parameters such as solution pH, concentration, contact time and ion strength on NH4(+) and PO4(3-) removal from solutions were investigated. Equilibrium isotherm data of adsorption of both NH4(+) and PO4(3-) were well fitted to the Freundlich model. Kinetic analysis showed that the pseudo-second-order kinetic model was more suitable for describing the whole adsorption process of NH4(+) and PO4(3-) on SARs. Overall, WSC-g-PKA/PVA semi-IPNs SAR showed better properties in comparison with WSC-g-PKA SAR and it could be considered as one efficient material for the removal and recovery of nitrogen and phosphorus with the agronomic reuse as a fertilizer. Copyright © 2013 Elsevier Ltd. All rights reserved.

A solid state fungal fermentation-based strategy for the hydrolysis of wheat straw☆

PubMed Central

Pensupa, Nattha; Jin, Meng; Kokolski, Matt; Archer, David B.; Du, Chenyu

2013-01-01

This paper reports a solid-state fungal fermentation-based pre-treatment strategy to convert wheat straw into a fermentable hydrolysate. Aspergillus niger was firstly cultured on wheat straw for production of cellulolytic enzymes and then the wheat straw was hydrolyzed by the enzyme solution into a fermentable hydrolysate. The optimum moisture content and three wheat straw modification methods were explored to improve cellulase production. At a moisture content of 89.5%, 10.2 ± 0.13 U/g cellulase activity was obtained using dilute acid modified wheat straw. The addition of yeast extract (0.5% w/v) and minerals significantly improved the cellulase production, to 24.0 ± 1.76 U/g. The hydrolysis of the fermented wheat straw using the fungal culture filtrate or commercial cellulase Ctec2 was performed, resulting in 4.34 and 3.13 g/L glucose respectively. It indicated that the fungal filtrate harvested from the fungal fermentation of wheat straw contained a more suitable enzyme mixture than the commercial cellulase. PMID:24121367

Heat treatment of wheat straw by immersion in hot water decreases mushroom yield in Pleurotus ostreatus.

PubMed

Jaramillo Mejía, Santiago; Albertó, Edgardo

2013-01-01

The oyster mushroom, Pleurotus ostreatus, is cultivated worldwide. It is one of the most appreciated mushrooms due to its high nutritional value. Immersion of the substrate in hot water is one of the most popular and worldwide treatment used for mushroom farmers. It is cheap and easy to implement. To compare the yields obtained during mushroom production of P. ostreatus using different pre-treatments (immersion in hot water, sterilization by steam and the use of fungicide) to determine if they influence mushroom crop. Four different treatments of substrate (wheat straw) were carried out: (i) immersion in hot water (IHW); (ii) steam sterilization; (iii) chemical; and (iv) untreated. The residual water from the IHW treatment was used to evaluate the mycelium growth and the production of P. ostreatus. Carbendazim treatment produced highest yields (BE: 106.93%) while IHW produced the lowest BE with 75.83%. Sugars, N, P, K and Ca were found in residual water of IHW treatment. The residual water increased the mycelium growth but did not increase yields. We have proved that IHW treatment of substrate reduced yields at least 20% when compared with other straw treatments such as steam, chemical or untreated wheat straw. Nutrients like sugars, proteins and minerals were found in the residual water extract which is the resultant water where the immersion treatment is carried out. The loss of these nutrients would be the cause of yield decrease. Alternative methods to the use of IHW as treatment of the substrate should be considered to reduce economical loss. Copyright © 2012 Revista Iberoamericana de Micología. Published by Elsevier Espana. All rights reserved.

Comparison of characterization and microbial communities in rice straw- and wheat straw-based compost for Agaricus bisporus production.

PubMed

Wang, Lin; Mao, Jiugeng; Zhao, Hejuan; Li, Min; Wei, Qishun; Zhou, Ying; Shao, Heping

2016-09-01

Rice straw (RS) is an important raw material for the preparation of Agaricus bisporus compost in China. In this study, the characterization of composting process from RS and wheat straw (WS) was compared for mushroom production. The results showed that the temperature in RS compost increased rapidly compared with WS compost, and the carbon (C)/nitrogen (N) ratio decreased quickly. The microbial changes during the Phase I and Phase II composting process were monitored using denaturing gradient gel electrophoresis (DGGE) and phospholipid fatty acid (PLFA) analysis. Bacteria were the dominant species during the process of composting and the bacterial community structure dramatically changed during heap composting according to the DGGE results. The bacterial community diversity of RS compost was abundant compared with WS compost at stages 4-5, but no distinct difference was observed after the controlled tunnel Phase II process. The total amount of PLFAs of RS compost, as an indicator of microbial biomass, was higher than that of WS. Clustering by DGGE and principal component analysis of the PLFA compositions revealed that there were differences in both the microbial population and community structure between RS- and WS-based composts. Our data indicated that composting of RS resulted in improved degradation and assimilation of breakdown products by A. bisporus, and suggested that the RS compost was effective for sustaining A. bisporus mushroom growth as well as conventional WS compost.

Photo-biohydrogen production potential of Rhodobacter capsulatus-PK from wheat straw

PubMed Central

2013-01-01

Background Biotechnological exploitation of lignocellulosic biomass is promising for sustainable and environmentally sound energy provision strategy because of the abundant availability of the renewable resources. Wheat straw (WS) comprising of 75-80% cellulose and hemicellulose is one of widely available, inexpensive and renewable lignocellulosic biomass types. The cellulosic and hemicellulose substrate can be hydrolyzed into monomeric sugars by chemical and/or biological methods. Results This study examined comparative potential of dilute acid and pre-ammonia pretreated and enzymatically hydrolyzed wheat straw (WS) for hydrogen production by purple non sulfur bacterium Rhodobacter capsulatus-PK. Gas production became noticeable after 14 h of inoculation in WS pretreated with 4% H2SO4. The detoxified liquid hydrolyzate (DLH) after overliming attained a production level of 372 mL-H2/L after 16 h under illumination of 120-150 W/m2 at 30 ± 2.0°C. Whereas the non-detoxified acid pretreated hydrolyzate (NDLH) of WS could produce only upto 254 mL-H2/L after 21 h post inoculation. Evolution of H2 became observable just after 10 ± 2.0 h of inoculation by employing 48 h age inoculum on the WS pretreated with 30% ammonia, hydrolyzed with cellulase 80 FPU/g and β-glucosidase 220 CbU/ml at 50°C. Upto 712 ml/L of culture was measured with continuous shaking for 24 h. The 47.5% and 64.2% higher hydrogen volume than the DLH and NDLH substrates, respectively appeared as a function of significantly higher monomeric sugar contents of the enzymatically hydrolyzed substrate and lesser/zero amounts of toxic derivatives including pH reducing agents. Conclusion Photofermentative hydrogen production from lignocellulosic waste is a feasible approach for eco-friendly sustainable supply of bioenergy in a cost-effective way. Results of this study provide new insight for addressing biotechnological exploitation of abundantly available and low-cost cellulosic substrates

Effect of wheat-maize straw return on the fate of nitrate in groundwater in the Huaihe River Basin, China.

PubMed

Li, Rongfu; Ruan, Xiaohong; Bai, Ying; Ma, Tianhai; Liu, Congqiang

2017-08-15

Straw return is becoming a routine practice in disposing of crop residues worldwide. However, the potential effect of such operation on the chemistry of local groundwater is not well documented. Here, shallow groundwater in an area where wheat-maize straw return is practiced was analyzed, and the seasonal changes in the nitrate concentration and the isotope compositions of NO 3 - and H 2 O were determined along two flow paths. Measured δD and δ 18 O in waters indicated that the groundwater was mainly recharged by atmospheric precipitation, while measured δ 15 N and δ 18 O in nitrate suggested that the sources for groundwater NO 3 - included urea fertilizer, soil nitrogen, and sewage/manure. Reduced NO 3 - concentrations coincided with an enrichment of organic matter in the groundwater of the straw return area, revealing an environmental condition that facilitates nitrate reduction, whereas increased δ 15 N-NO 3 - and δ 18 O-NO 3 - along the flow path suggested the occurrence of denitrification. Further analyses showed that, compared to the cases in the absence of straw return, as much as 80% and 90% of groundwater nitrate was removed in low and high water seasons in the straw return area, pointing to a potential positive effect of straw return to groundwater quality. Copyright © 2017 Elsevier B.V. All rights reserved.

Fibrolytic potential of anaerobic fungi (Piromyces sp.) isolated from wild cattle and blue bulls in pure culture and effect of their addition on in vitro fermentation of wheat straw and methane emission by rumen fluid of buffaloes.

PubMed

Paul, Shyam S; Deb, Sitangshu M; Punia, Balbir S; Singh, Dharminder; Kumar, Rajiv

2010-05-01

Ten isolates of anaerobic fungi of Piromyces genus from wild cattle and blue bulls (five isolates from each host species) were evaluated for their fibrolytic ability in pure culture, their suitability for use as a microbial additive in buffaloes and their effect on methane emission. In pure culture, only two out of five isolates from wild cattle degraded wheat straw efficiently, whereas all five isolates from wild blue bulls did. Isolate CF1 (from cattle) showed the highest apparent digestibility (53.4%), true digestibility (70.8%) and neutral detergent fibre digestibility (75.0%) of wheat straw after 5 days of incubation. When added to buffalo rumen fluid, all five isolates from cattle increased (P < 0.05) in vitro apparent digestibility of wheat straw compared with the control (received autoclaved culture), but all five isolates from blue bulls failed to influence in vitro digestibility of wheat straw. Isolate CF1 showed the highest stimulating effect on straw digestion by buffalo rumen fluid microbes and increased apparent digestibility (51.9 vs 29.4%, P < 0.05), true digestibility (57.9 vs 36.5%, P < 0.05) and neutral detergent fibre digestibility (51.5 vs 26.9%, P < 0.05) of wheat straw compared with the control after 24 h of fermentation. There were also significant increases in fungal count and enzyme activities of carboxymethylcellulase and xylanase in the CF1-added group compared with the control group. Gas and methane production g(-1) truly digested dry matter of straw were comparable among all groups including the control. Wild cattle and blue bulls harbour some anaerobic fungal strains with strong capability to hydrolyse fibre. The fungal isolate CF1 has high potential for use as a microbial feed additive in buffaloes to improve digestibility of fibrous feeds without increasing methane emission per unit of digested feed.

Characterization of Lignin in Situ by Photoacoustic Spectroscopy

PubMed Central

Gould, J. Michael

1982-01-01

Photoacoustic spectroscopy is a recently developed nondestructive analytical technique that provides ultraviolet, visible, and infrared absorption spectra from intensely light scattering, solid, and/or optically opaque materials not suitable for conventional spectrophotometric analysis. In wood and other lignocellulosics, the principal ultraviolet absorption bands, in the absence of photosynthetic pigments, arise from the aromatic lignin component of the cell walls. Photoacoustic spectra of extracted lignin fragments (milled wood lignin) and synthetic lignin-like polymers contain a single major absorption band at 280 nanometers with an absorption tail extending beyond 400 nanometers. Photoacoustic spectra of pine, maple, and oak lignin in situ contain a broad primary absorption band at 300 nanometers and a longer wavelength shoulder around 370 nanometers. Wheat lignin in situ, on the other hand, exhibits two principle absorption peaks, at 280 nanometers and 320 nanometers. The presence of absorption bands at wavelengths greater than 300 nanometers in intact lignin could result from (a) interacting, nonconjugated chromophores, or (b) the presence of more highly conjugated structural components formed as the result of oxidation of the polymer. Evidence for the latter comes from the observation that, on the outer surface of senescent, field-dried wheat culms (stems), new absorption bands in the 350 to 400 nanometer region predominate. These new bands are less apparent on the outer surface of presenescent wheat culms and are virtually absent on the inner surface of either senescent or presenescent culms, suggesting that the appearance of longer wavelength absorption bands in senescent wheat is the result of accumulated photochemical modifications of the ligin polymer. These studies also demonstrate photoacoustic spectroscopy to be an important new tool for the investigation of insoluble plant components. PMID:16662709

Pretreatment of corn straw using the alkaline solution of ionic liquids.

PubMed

Liu, Zhen; Li, Longfei; Liu, Cheng; Xu, Airong

2018-07-01

In the present work, the pretreatment of corn stalk with the solution of 1-ethyl-3-methylimidazolium acetate ([Emim]Ac) ionic liquid containing NaOH was explored for its lignin removal. The effects of reaction temperature, reaction time, and solid-liquid ratio on the lignin removal efficiency were determined by the response surface methodology (RSM). The pretreatment conditions were optimized by the Box-Behnken design and the comparative study of the composition and structure of corn straw before and after the pretreatment to be: reaction temperature 98.5 °C, reaction time 1.31 h, and solid-liquid ratio 1:8.7. Under the optimized conditions, the cellulose and hemicellulose contents of the corn straw were increased to 85.69% and 9.1%, respectively, and the lignin content was reduced to 2.27% with the lignin removal efficiency up to 87.4%. Copyright © 2018 Elsevier Ltd. All rights reserved.

[Effects of applying inorganic P and wheat straw on the microbial biomass P and microbial P concentration in a calcareous soil with low concentration available P].

PubMed

Zhao, Xiao-Rong; Zhou, Ran; Li, Gui-Tong; Lin, Qi-Mei

2009-02-01

In an incubation test, a calcareous soil with low concentration of available P was amended with KH2PO4 (0, 25, 50, and 100 mg P x kg(-1)) and ground wheat straw (5 g C x kg(-1)), and incubated at 25 degrees C for 90 days. The aim was to investigate the change patterns of soil microbial biomass P and microbial P concentration as well as their relationships with soil available P. The results showed that both soil microbial biomass P and microbial P concentration increased with increasing inorganic P addition, with the maximum being 71.37 and 105.34 mg x kg(-1), respectively. The combined application of inorganic P (except 100 mg P x kg(-1)) and wheat straw decreased the soil microbial biomass P and microbial P concentration, being most obvious at early incubation period. Soil microbial biomass P and microbial P concentration had significant positive correlations (P < 0.05) with soil available P (R2 = 0.26 and 0.40, n = 49, respectively). The applied P could rapidly transform into microbial biomass P. The maximum apparent contribution rate of applied P to microbial biomass P was 71%. The added wheat straw could further improve the apparent contribution rate.

Chemical composition, silage fermentation characteristics, and in vitro ruminal fermentation parameters of potato-wheat straw silage treated with molasses and lactic acid bacteria and corn silage.

PubMed

Babaeinasab, Y; Rouzbehan, Y; Fazaeli, H; Rezaei, J

2015-09-01

The aim of this study was to determine the effect of molasses and lactic acid bacteria (LAB) on the chemical composition, silage fermentation characteristics, and in vitro ruminal fermentation parameters of an ensiled potato-wheat straw mixture in a completely randomized design with 4 replicates. Wheat straw was harvested at full maturity and potato tuber when the leaves turned yellowish. The potato-wheat straw (57:43 ratio, DM basis) mixture was treated with molasses, LAB, or a combination. Lalsil Fresh LB (Lallemand, France; containing NCIMB 40788) or Lalsil MS01 (Lallemand, France; containing MA18/5U and MA126/4U) were each applied at a rate of 3 × 10 cfu/g of fresh material. Treatments were mixed potato-wheat straw silage (PWSS) without additive, PWSS inoculated with Lalsil Fresh LB, PWSS inoculated with Lalsil MS01, PWSS + 5% molasses, PWSS inoculated with Lalsil Fresh LB + 5% molasses, PWSS inoculated with Lalsil MS01 + 5% molasses, and corn silage (CS). The compaction densities of PWSS treatments and CS were approximately 850 and 980 kg wet matter/m, respectively. After anaerobic storage for 90 d, chemical composition, silage fermentation characteristics, in vitro gas production (GP), estimated OM disappearance (OMD), ammonia-N, VFA, microbial CP (MCP) production, and cellulolytic bacteria count were determined. Compared to CS, PWSS had greater ( < 0.001) values of DM, ADL, water-soluble carbohydrates, pH, and ammonia-N but lower ( < 0.05) values of CP, ash free-NDF (NDFom), ash, nitrate, and lactic, acetic, propionic, and butyric acids concentrations. When PWSS was treated with molasses, LAB, or both, the contents of CP and lactic and acetic acids increased, whereas NDFom, ammonia-N, and butyric acid decreased ( < 0.05). Based on in vitro ruminal experiments, PWSS had greater ( < 0.05) values of GP, OMD, and MCP but lower ( < 0.05) VFA and acetic acid compared to CS. With adding molasses alone or in combination with LAB inoculants to PWSS, the values of GP

Impact of organic loading rate on the performance of psychrophilic dry anaerobic digestion of dairy manure and wheat straw: long-term operation.

PubMed

Saady, Noori M Cata; Massé, Daniel I

2015-04-01

Development of efficient processes for valorising animal wastes would be a major advancement in cold-climate regions. This paper reports the results of long term (315 days experiment) of novel psychrophilic (20°C) dry anaerobic digestion (PDAD) of cow feces and wheat straw in laboratory scale sequence batch reactor operated at increasing organic loading rate. The PDAD process fed with a mixture of feces and straw (TS of 27%) over a treatment cycle length of 21 days at organic loading rate (OLR) 4.0, 5.0 and 6.0 g TCOD kg(-1) inoculum d(-1) (of 2.9 ± 0.1, 3.7 ± 0.1, and 4.4 ± 0.1g VS kg(-1) inoculum d(-1), respectively) resulted in average specific methane yield (SMY) of 187.3 ± 18.1, 163.6 ± 39.5, 150.8 ± 32.9 N L CH4 kg(-1)VS fed, respectively. PDAD of cow feces and wheat straw is possible with VS-based inoculum-to-substrate ratio of 1.4 at OLR of 6.0 g TCOD kg(-1) inoculum d(-1). Hydrolysis was the limiting step reaction. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

Optimization of organosolv pretreatment of rice straw for enhanced biohydrogen production using Enterobacter aerogenes.

PubMed

Asadi, Nooshin; Zilouei, Hamid

2017-03-01

Ethanol organosolv pretreated rice straw was used to produce biohydrogen using Enterobacter aerogenes. The effect of temperature (120-180°C), residence time (30-90min), and ethanol concentration (45-75%v/v) on the hydrogen yield, residual biomass, and lignin recovery was investigated using RSM. In contrast to the residual solid and lignin recovery, no considerable trend could be observed for the changes in the hydrogen yield at different treatment severities. The maximum hydrogen yield of 19.73mlg -1 straw was obtained at the ethanol concentration of 45%v/v and 180°C for 30min. Furthermore, the potential amount of biohydrogen was estimated in the top ten rice producing nations using the experimental results. Approximately 355.8kt of hydrogen and 11.3Mt of lignin could globally be produced. Based on a Monte Carlo analysis, the production of biohydrogen from rice straw has the lowest risk in China and the highest in Japan. Copyright © 2016 Elsevier Ltd. All rights reserved.

Acid-catalyzed autohydrolysis of wheat straw to improve sugar recovery.

PubMed

Ertas, Murat; Han, Qiang; Jameel, Hasan

2014-10-01

A comparison study of autohydrolysis and acid-catalyzed autohydrolysis of wheat straw was performed to understand the impact of acid addition on overall sugar recovery. Autohydrolysis combined with refining is capable of achieving sugar recoveries in the mid 70s. If the addition of a small amount of acid is capable of increasing the sugar recovery even higher it may be economically attractive. Acetic, sulfuric, hydrochloric and sulfurous acids were selected for acid-catalyzed autohydrolysis pretreatments. Autohydrolysis with no acid at 190 °C showed the highest total sugar in the prehydrolyzate. Enzymatic hydrolysis was performed for all the post-treated solids with and without refining at enzyme loadings of 4 and 10 FPU/g for 96 h. Acid-catalyzed autohydrolysis at 190 °C with sulfurous acid showed the highest total sugar recovery of 81.2% at 4 FPU/g enzyme charge compared with 64.3% at 190 °C autohydrolysis without acid. Copyright © 2014 Elsevier Ltd. All rights reserved.

Celluclast and Cellic® CTec2: Saccharification/fermentation of wheat straw, solid-liquid partition and potential of enzyme recycling by alkaline washing.

PubMed

Rodrigues, Ana Cristina; Haven, Mai Østergaard; Lindedam, Jane; Felby, Claus; Gama, Miguel

2015-11-01

The hydrolysis/fermentation of wheat straw and the adsorption/desorption/deactivation of cellulases were studied using Cellic(®) CTec2 (Cellic) and Celluclast mixed with Novozyme 188. The distribution of enzymes - cellobiohydrolase I (Cel7A), endoglucanase I (Cel7B) and β-glucosidase - of the two formulations between the residual substrate and supernatant during the course of enzymatic hydrolysis and fermentation was investigated. The potential of recyclability using alkaline wash was also studied. The efficiency of hydrolysis with an enzyme load of 10 FPU/g cellulose reached >98% using Cellic(®) CTec2, while for Celluclast a conversion of 52% and 81%, was observed without and with β-glucosidase supplementation, respectively. The decrease of Cellic(®) CTec2 activity observed along the process was related to deactivation of Cel7A rather than of Cel7B and β-glucosidase. The adsorption/desorption profiles during hydrolysis/fermentation revealed that a large fraction of active enzymes remained adsorbed to the solid residue throughout the process. Surprisingly, this was the case of Cel7A and β-glucosidase from Cellic, which remained adsorbed to the solid fraction along the entire process. Alkaline washing was used to recover the enzymes from the solid residue. This method allowed efficient recovery of Celluclast enzymes; however, this may be achieved only when minor amounts of cellulose remain present. Regarding the Cellic formulation, neither the presence of cellulose nor lignin restricted an efficient desorption of the enzymes at alkaline pH. This work shows that the recycling strategy must be customized for each particular formulation, since the enzymes found e.g. in Cellic and Celluclast bear quite different behaviour regarding the solid-liquid distribution, stability and cellulose and lignin affinity. Copyright © 2015 Elsevier Inc. All rights reserved.

[Effect of straw-returning on the storage and distribution of different active fractions of soil organic carbon].

PubMed

Wang, Hul; Wang, Xu-dong; Tian, Xiao-hong

2014-12-01

The impacts of straw mulching and returning on the storage of soil dissolved organic carbon (DOC), particulate organic carbon (POC) and mineral associated organic carbon (MOC), and their proportions to the total organic carbon (TOC) were studied based on a field experiment. The results showed that compared to the treatment of wheat straw soil-returning (WR), the storage of TOC and MOC decreased by 4.1% and 9.7% respectively in 0-20 cm soil in the treatment with wheat straw mulching (WM), but the storage of DOC and POC increased by 207.7% and 11.9%, and TOC and POC increased significantly in 20-40 cm soil. Compared to the treatment with maize straw soil-returning (MR), the storage of TOC and MOC in the plough pan soil of the treatment with maize straw mulching (MM) increased by 13.6% and 14.6% , respectively. Compared to the WR-MR treatment, the storage of TOC and MOC in top soil (0-20 icm) significantly decreased by 8.5% and 10.3% respectively in WM-MM treatment. The storage of TOC, and POC in top soil was significantly higher in the treatments with maize straw soil-returning or mulching than that with wheat straw. Compared to the treatment without straw (CK), the storage of TOC in top soil increased by 5.2% to 18.0% in the treatments with straw returning or mulching in the six modes (WM, WR, MM, MR, WM-MM,WR-MR) (P<0.05), but the storage of TOC in the plough pan soil decreased by 8.0% to 11.5% (P<0.05) except for the treatments of WM and MM. The storage of DOC and DOC/TOC ratio decreased significantly in top soil in the treatments with straw mulching or returning in six modes. The storage of POC and POC/TOC ratio in WM and WM-MM treatments, MOC and MOC/TOC ratio in WR treatment, increased significantly in top soil. In the other three treatments with straw mulching and returning (MM, MR, WR-MR), the storage of POC and MOC increased significantly in top soil. These results suggested that straw mulching had the potential to accumulate active organic carbon fraction

Effects of straw mulch on soil water and winter wheat production in dryland farming

PubMed Central

Peng, Zhang; Ting, Wei; Haixia, Wang; Min, Wang; Xiangping, Meng; Siwei, Mou; Rui, Zhang; Zhikuan, Jia; Qingfang, Han

2015-01-01

The soil water supply is the main factor that limits dryland crop production in China. In a three-year field experiment at a dryland farming experimental station, we evaluated the effects of various straw mulch practices on soil water storage, grain yield, and water use efficiency (WUE) of winter wheat (Triticum aestivum). Field experiments were conducted with six different mulch combinations (two different mulch durations and three different mulch amounts): high (SM1; 9000 kg ha−1), medium (SM2; 6000 kg ha−1), and low (SM3; 3000 kg ha−1) straw mulch treatments for the whole period; and high (SM4), medium (SM5) and low (SM6) straw mulch treatments during the growth period only, where the control was the whole period without mulch (CK). Throughout the whole growth period of the three-year experiment, the average soil water content in the 0–200 cm soil layer increased by 0.7–22.5% compared with CK, while the WUE increased significantly by 30.6%, 32.7% and 24.2% with SM1, SM2, and SM3, respectively (P < 0.05). The yield increased by 13.3–23.0% when mulch was provided during the growth period, while the WUE increased by 15.2%, 17.2% and 18.0% with SM4, SM5, and SM6, respectively, compared with CK. PMID:26035528

Improving the fermentation quality of wheat straw silage stored at low temperature by psychrotrophic lactic acid bacteria.

PubMed

Zhang, Miao; Lv, Haoxin; Tan, Zhongfang; Li, Ya; Wang, Yanping; Pang, Huili; Li, Zongwei; Jiao, Zhen; Jin, Qingsheng

2017-02-01

This study aimed to explore the feasible approaches to develop a silage production technique in regions with low temperatures. An effective low-temperature silage technology system was constructed and two frigostable Lactobacillus (L.) strains isolated from alpine pastures were selected and proved to be available for wheat straw silage at 5°C. The strains QZ227 and QZ887 were both identified as L. plantarum according to the phenotype, 16S rRNA, and RecA gene analysis. QZ227, QZ887 and a commercial inoculant FG1 consisting of L. plantarum were effective for improving the fermentation quality of wheat straws silage at 5°C for 30 days as indicated by the higher content of lactic acid and for 60 days by lower pH values, while the control with sterile water instead conferred reduced benefits. Additionally, silages fermented at low temperature proved to be acceptable for feeding livestock after being placed in a simulated environmental temperature of 20°C for 14 days to detect its edibility during the early spring when the temperature begins to rise. Both QZ227 and QZ887 showed potential applications of silage making in frigid areas and were effective inoculants in a low-temperature silage technology system. © 2016 Japanese Society of Animal Science.

Effect of the combined physical and chemical treatments with microbial fermentation on corn straw degradation.

PubMed

Guo, Hongwei; Chang, Juan; Yin, Qingqiang; Wang, Ping; Lu, Min; Wang, Xiao; Dang, Xiaowei

2013-11-01

In order to improve corn straw degradation, steam explosion, sodium hydroxide soaking and Aspergillus oryzae fermentation were used. The optimal sodium hydroxide pretreatment condition for lignin degradation was obtained. The degradation rates of hemicellulose, cellulose and lignin were 54.68%, 17.76% and 33.14% for the exploded straw (P<0.05); 67.92%, 2.44% (P>0.05) and 76.54% for the alkali-treated straw (P<0.05); 75.98%, 39.93% and 77.88% for the exploded and alkali-treated straw (P<0.05), respectively. The following microbial fermentation could degrade hemicellulose and cellulose further (P<0.05). Cellulase, amylase and protease activities produced during microbial fermentation in the pretreated corn straw were lower than that in the untreated one (P<0.05); however, glucose content was increased by microbial fermentation (P<0.05). It can be concluded that the combined treatments of steam explosion, sodium hydroxide and microbial fermentation will be a good method for straw degradation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Genetic loci simultaneously controlling lignin monomers and biomass digestibility of rice straw.

PubMed

Hu, Zhen; Zhang, Guifen; Muhammad, Ali; Samad, Rana Abdul; Wang, Youmei; Walton, Jonathan D; He, Yuqing; Peng, Liangcai; Wang, Lingqiang

2018-02-26

Lignin content and composition are crucial factors affecting biomass digestibility. Exploring the genetic loci simultaneously affecting lignin-relevant traits and biomass digestibility is a precondition for lignin genetic manipulation towards energy crop breeding. In this study, a high-throughput platform was employed to assay the lignin content, lignin composition and biomass enzymatic digestibility of a rice recombinant inbred line population. Correlation analysis indicated that the absolute content of lignin monomers rather than lignin content had negative effects on biomass saccharification, whereas the relative content of p-hydroxyphenyl unit and the molar ratio of p-hydroxyphenyl unit to guaiacyl unit exhibited positive roles. Eight QTL clusters were identified and four of them affecting both lignin composition and biomass digestibility. The additive effects of clustered QTL revealed consistent relationships between lignin-relevant traits and biomass digestibility. Pyramiding rice lines containing the above four positive alleles for increasing biomass digestibility were selected and showed comparable lignin content, decreased syringyl or guaiacyl unit and increased molar percentage of p-hydroxyphenyl unit, the molar ratio of p-hydroxyphenyl unit to guaiacyl unit and sugar releases. More importantly, the lodging resistance and eating/cooking quality of pyramiding lines were not sacrificed, indicating the QTL information could be applied to select desirable energy rice lines.

Multiscale Alterations in Sugar Cane Bagasse and Straw Submitted to Alkaline Deacetylation

DOE PAGES

Lima, Cleilton S.; Rabelo, Sarita C.; Ciesielski, Peter N.; ...

2018-01-31

Alkaline deacetylation has emerged as a promising chemistry for pretreatments performed prior to enzymatic saccharification of lignocellulosic biomass. This process avoids complex pressurized reactors and opens new opportunities for lignin covalorization. In this work, we evaluate the chemical and morphological response of sugar cane bagasse and straw submitted to alkaline treatments. Alkaline solutions for deacetylation (0.4% w/w NaOH, 70 degrees C, 3 h) as well as proximal conditions (0.1-0.7% NaOH, 55-85 degrees C, 1-5 h) chosen by 23 experimental design were evaluated. The deacetylation treatment removes ~90% of the acetyl groups and 20-30% of the lignin from both bagasse andmore » straw, while removal of ~20% of the xylan and glucan is observed in straw, but not in bagasse. Considering nanoscale structural alterations, neither cellulose cocrystallization (evaluated by X-ray diffraction) nor formation of lignin aggregates (evaluated by thermoporometric signature) are observed after the alkaline conditions, in contrast to observations after hydrothermal treatments. Furthermore, calorimetric thermoporometry as well as scanning and transmission electron microscopies show substantial introduction of nanoscale porosity and loosening of the tissue and cell wall structures, indicating desirable mechanical weakening and gains in enzyme accessibility. These results provide fundamental and practical knowledge for biorefineries based on alkaline deacetylation of sugar cane bagasse and straw.« less

Multiscale Alterations in Sugar Cane Bagasse and Straw Submitted to Alkaline Deacetylation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lima, Cleilton S.; Rabelo, Sarita C.; Ciesielski, Peter N.

Alkaline deacetylation has emerged as a promising chemistry for pretreatments performed prior to enzymatic saccharification of lignocellulosic biomass. This process avoids complex pressurized reactors and opens new opportunities for lignin covalorization. In this work, we evaluate the chemical and morphological response of sugar cane bagasse and straw submitted to alkaline treatments. Alkaline solutions for deacetylation (0.4% w/w NaOH, 70 degrees C, 3 h) as well as proximal conditions (0.1-0.7% NaOH, 55-85 degrees C, 1-5 h) chosen by 23 experimental design were evaluated. The deacetylation treatment removes ~90% of the acetyl groups and 20-30% of the lignin from both bagasse andmore » straw, while removal of ~20% of the xylan and glucan is observed in straw, but not in bagasse. Considering nanoscale structural alterations, neither cellulose cocrystallization (evaluated by X-ray diffraction) nor formation of lignin aggregates (evaluated by thermoporometric signature) are observed after the alkaline conditions, in contrast to observations after hydrothermal treatments. Furthermore, calorimetric thermoporometry as well as scanning and transmission electron microscopies show substantial introduction of nanoscale porosity and loosening of the tissue and cell wall structures, indicating desirable mechanical weakening and gains in enzyme accessibility. These results provide fundamental and practical knowledge for biorefineries based on alkaline deacetylation of sugar cane bagasse and straw.« less

Separate hydrolysis and co-fermentation for improved xylose utilization in integrated ethanol production from wheat meal and wheat straw

PubMed Central

2012-01-01

Background The commercialization of second-generation bioethanol has not been realized due to several factors, including poor biomass utilization and high production cost. It is generally accepted that the most important parameters in reducing the production cost are the ethanol yield and the ethanol concentration in the fermentation broth. Agricultural residues contain large amounts of hemicellulose, and the utilization of xylose is thus a plausible way to improve the concentration and yield of ethanol during fermentation. Most naturally occurring ethanol-fermenting microorganisms do not utilize xylose, but a genetically modified yeast strain, TMB3400, has the ability to co-ferment glucose and xylose. However, the xylose uptake rate is only enhanced when the glucose concentration is low. Results Separate hydrolysis and co-fermentation of steam-pretreated wheat straw (SPWS) combined with wheat-starch hydrolysate feed was performed in two separate processes. The average yield of ethanol and the xylose consumption reached 86% and 69%, respectively, when the hydrolysate of the enzymatically hydrolyzed (18.5% WIS) unwashed SPWS solid fraction and wheat-starch hydrolysate were fed to the fermentor after 1 h of fermentation of the SPWS liquid fraction. In the other configuration, fermentation of the SPWS hydrolysate (7.0% WIS), resulted in an average ethanol yield of 93% from fermentation based on glucose and xylose and complete xylose consumption when wheat-starch hydrolysate was included in the feed. Increased initial cell density in the fermentation (from 5 to 20 g/L) did not increase the ethanol yield, but improved and accelerated xylose consumption in both cases. Conclusions Higher ethanol yield has been achieved in co-fermentation of xylose and glucose in SPWS hydrolysate when wheat-starch hydrolysate was used as feed, then in co-fermentation of the liquid fraction of SPWS fed with the mixed hydrolysates. Integration of first-generation and second

Effects of straw and plastic film mulching on greenhouse gas emissions in Loess Plateau, China: A field study of 2 consecutive wheat-maize rotation cycles.

PubMed

Chen, Haixin; Liu, Jingjing; Zhang, Afeng; Chen, Jing; Cheng, Gong; Sun, Benhua; Pi, Xiaomin; Dyck, Miles; Si, Bingcheng; Zhao, Ying; Feng, Hao

2017-02-01

Mulching practices have long been used to modify the soil temperature and moisture conditions and thus potentially improve crop production in dryland agriculture, but few studies have focused on mulching effects on soil gaseous emissions. We monitored annual greenhouse gas (GHG) emissions under the regime of straw and plastic film mulching using a closed chamber method on a typical winter-wheat (Triticum aestivum L. cv Xiaoyan 22) and summer-maize (Zea mays L. cv Qinlong 11) rotation field over two-year period in the Loess Plateau, northwestern China. The following four field treatments were included: T1 (control, no mulching), T2 (4000kgha -1 wheat straw mulching, covering 100% of soil surface), T3 (half plastic film mulching, covering 50% of soil surface), and T4 (complete plastic film mulching, covering 100% of soil surface). Compared with the control, straw mulching decreased soil temperature and increased soil moisture, whereas plastic film mulching increased both soil temperature and moisture. Accordingly, straw mulching increased annual crop yields over both cycles, while plastic film mulching significantly enhanced annual crop yield over cycle 2. Compared to the no-mulching treatment, all mulching treatments increased soil CO 2 emission over both cycles, and straw mulching increased soil CH 4 absorption over both cycles, but patterns of soil N 2 O emissions under straw or film mulching are not consistent. Overall, compared to T1, annual GHG intensity was significantly decreased by 106%, 24% and 26% under T2, T3 and T4 over cycle 1, respectively; and by 20%, 51% and 29% under T2, T3 and T4 over cycle 2, respectively. Considering the additional cost and environmental issues associated with plastic film mulching, the application of straw mulching might achieve a balance between food security and GHG emissions in the Chinese Loess Plateau. However, further research is required to investigate the perennial influence of different mulching applications. Copyright

Improving lead adsorption through chemical modification of wheat straw by lactic acid

NASA Astrophysics Data System (ADS)

Mu, Ruimin; Wang, Minxiang; Bu, Qingwei; Liu, Dong; Zhao, Yanli

2018-01-01

This work describes the creation of a new cellulosic material derived from wheat straw modified by lactic acid for adsorption of lead in aqueous solution, called 0.3LANS (the concentration of the lactic acid were 0.3mol/L). Batch experiments were conducted to study the effects of initial pH value, contact time, adsorbent dose, initial concentration and temperature. Fourier transform infrared (FTIR), Elemental analysis, BET surface area and Scanning electron micrographs (SEM) analysis were used to investigate the chemical modification. Adsorption isotherm models namely, Langmuir, Freundlich were used to analyse the equilibrium data, and the Langmuir isotherm model provided the best correlation, means that the adsorption was chemical monolayer adsorption and the adsorption capacity qm was increased with increasing temperature, and reached 51.49mg/g for 0.3LANS at 35°C, showing adsorption was exothermic.

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

NASA Astrophysics Data System (ADS)

Georgieva, Tania I.; Mikkelsen, Marie J.; Ahring, Birgitte K.

Thermophilic ethanol fermentation of wet-exploded wheat straw hydrolysate was investigated in a continuous immobilized reactor system. The experiments were carried out in a lab-scale fluidized bed reactor (FBR) at 70°C. Undetoxified wheat straw hydrolysate was used (3-12% dry matter), corresponding to sugar mixtures of glucose and xylose ranging from 12 to 41 g/1. The organism, thermophilic anaerobic bacterium Thermoanaerobacter BG1L1, exhibited significant resistance to high levels of acetic acid (up to 10 g/1) and other metabolic inhibitors present in the hydrolysate. Although the hydrolysate was not detoxified, ethanol yield in a range of 0.39-0.42 g/g was obtained. Overall, sugar efficiency to ethanol was 68-76%. The reactor was operated continuously for approximately 143 days, and no contamination was seen without the use of any agent for preventing bacterial infections. The tested microorganism has considerable potential to be a novel candidate for lignocellulose bioconversion into ethanol. The work reported here also demonstrates that the use of FBR configuration might be a viable approach for thermophilic anaerobic ethanol fermentation.

[Degradation of lignocellulose in the corn straw by Bacillus amyloliquefaciens MN-8].

PubMed

Li, Hong-ya; Li, Shu-na; Wang, Shu-xiang; Wang, Quan; Xue, Yin-yin; Zhu, Bao-cheng

2015-05-01

Microbial degradation of lignocellulose is one of the key problems that need to be solved urgently in the process of utilizing biomass resource. Bacillus amyloliquefaciens MN-8 is our previously isolated bacterium capable of degrading lignin. To determine the capability of strain MN-8 to degrade lignocellulose of corn straw, B. amyloliquefaciens MN-8 was inoculated and fermented with solid-state corn straw powder-MSM culture medium. The changes in the enzyme activity and degradation products of lignocellulose were monitored in the process of fermentation using the FTIR and GC/MS. The results showed that B. amyloliquefaciens MN-8 could produce lignin peroxidase, manganese peroxidase, cellulase and hemicellulase enzymes. The activities of all these enzymes reached the peak after being incubated for 10-16 days, and the highest enzyme activities were 55.0, 16.7, 45.4 and 60.5 U · g(-1), respectively. After 24 d of incubation, the degradation percentages of lignin, cellulose and hemicellulose were up to 42.9%, 40.6% and 27.1%, respectively. The spectroscopic data by FTIR indicated that the intensities of characteristic absorption peaks of lignin, cellulose and hemicellulose of the corn straw were decreased, indicating that the lignocellulose was degraded partly after being fermented by B. amyloliquefaciens MN-8. GC/MS analysis also demonstrated that strain MN-8 could degrade lignocellulose efficiently. It could depolymerize lignin into some monomeric compounds with retention of phenylpropane structure unit, such as amphetamine, benzene acetone and benzene propanoic acids, by the rupture of β-O-4 bond connected between lignin monomer, and it further oxidized some monomer compounds into Cα carbonyl compounds, such as 2-amino-1-benzeneacetone and 4-hydroxy-3,5-dimethoxy-acetophenone. The GC/MS analysis of the degradation products of cellulose and hemicellulose showed that there were not only monosaccharide compounds, such as glucose, mannose and galactose, but also some

Process design of SSCF for ethanol production from steam-pretreated, acetic-acid-impregnated wheat straw.

PubMed

Bondesson, Pia-Maria; Galbe, Mats

2016-01-01

Pretreatment is an important step in the production of ethanol from lignocellulosic material. Using acetic acid together with steam pretreatment allows the positive effects of an acid catalyst to be retained, while avoiding the negative environmental effects associated with sulphuric acid. Acetic acid is also formed during the pretreatment and hydrolysis of hemicellulose, and is a known inhibitor that may impair fermentation at high concentrations. The purpose of this study was to improve ethanol production from glucose and xylose in steam-pretreated, acetic-acid-impregnated wheat straw by process design of simultaneous saccharification and co-fermentation (SSCF), using a genetically modified pentose fermenting yeast strain Saccharomyces cerevisiae . Ethanol was produced from glucose and xylose using both the liquid fraction and the whole slurry from pretreated materials. The highest ethanol concentration achieved was 37.5 g/L, corresponding to an overall ethanol yield of 0.32 g/g based on the glucose and xylose available in the pretreated material. To obtain this concentration, a slurry with a water-insoluble solids (WIS) content of 11.7 % was used, using a fed-batch SSCF strategy. A higher overall ethanol yield (0.36 g/g) was obtained at 10 % WIS. Ethanol production from steam-pretreated, acetic-acid-impregnated wheat straw through SSCF with a pentose fermenting S. cerevisiae strain was successfully demonstrated. However, the ethanol concentration was too low and the residence time too long to be suitable for large-scale applications. It is hoped that further process design focusing on the enzymatic conversion of cellulose to glucose will allow the combination of acetic acid pretreatment and co-fermentation of glucose and xylose.

[Influence of Different Straws Returning with Landfill on Soil Microbial Community Structure Under Dry and Water Farming].

PubMed

Lan, Mu-ling; Gao, Ming

2015-11-01

Based on rice, wheat, corn straw and rape, broad bean green stalk as the research object, using phospholipid fatty acid (PLFA) method, combining principal component analysis method to study the soil microbial quantity, distribution of flora, community structure characteristics under dry and water farming as two different cultivated land use types. The PLFA analysis results showed that: under dry farming, total PLFA quantity ranged 8.35-25.15 nmol x g(-1), showed rape > broad bean > corn > rice > wheat, rape and broad bean significantly increased total PLFA quantity by 1.18 and 1.08 times compared to the treatment without straw; PLFA quantity of bacterial flora in treatments with straws was higher than that without straw, and fungal biomass was significantly increased, so was the species richness of microbial community. Under water faming, the treatments of different straws returning with landfill have improved the PLFA quantity of total soil microbial and flora comparing with the treatment without straw, fungi significantly increased, and species richness of microbial communities value also increased significantly. Total PLFA quantity ranged 4.04-22.19 nmol x g(-1), showed rice > corn > wheat > broad bean > rape, which in rape and broad bean treatments were lower than the treatment without straw; fungal PLFA amount in 5 kinds of straw except broad bean treatment was significantly higher than that of the treatment without straw, bacteria and total PLFA quantity in broad bean processing were significantly lower than those of other treatments, actinomycetes, G+, G- had no significant difference between all treatments; rice, wheat, corn, rape could significantly increase the soil microbial species richness index and dominance index under water faming. The results of principal component analysis showed that broad bean green stalk had the greatest impact on the microbial community structure in the dry soil, rape green stalk and wheat straw had the biggest influence on

Release kinetics of esterified p-coumaric acid and ferulic acid from rice straw in mild alkaline solution.

PubMed

Linh, Tran Ngoc; Fujita, Hirokata; Sakoda, Akiyoshi

2017-05-01

The release kinetics of esterified p-coumaric acid (PCA) and ferulic acid (FA) from rice straw under a mild alkaline condition were investigated to collect fundamental data for the design of a recovery process. The results showed that the straw size, NaOH concentration, and temperature were the key parameters governing release kinetics. The analysis demonstrated that FA is released considerably faster than PCA. The close relationship between lignin and the PCA dissolution indicates a reciprocal and/or simultaneous release. Moreover, PCA is broadly distributed in the lignin network but tends to be located more densely in the lignin fraction which is not easily solubilized by alkaline treatment. In contrast, the release of FA is strongly affected by removal of lignin fraction which is easily solubilized. These results suggest that the release kinetics are controlled by the accessibility of NaOH to their ester sites in the lignin/hemicellulose network, and by their localization. Copyright © 2017 Elsevier Ltd. All rights reserved.

Lactic acid production from lime-treated wheat straw by Bacillus coagulans: neutralization of acid by fed-batch addition of alkaline substrate

PubMed Central

Maas, Ronald H. W.; Bakker, Robert R.; Jansen, Mickel L. A.; Visser, Diana; de Jong, Ed; Eggink, Gerrit

2008-01-01

Conventional processes for lignocellulose-to-organic acid conversion requires pretreatment, enzymatic hydrolysis, and microbial fermentation. In this study, lime-treated wheat straw was hydrolyzed and fermented simultaneously to lactic acid by an enzyme preparation and Bacillus coagulans DSM 2314. Decrease in pH because of lactic acid formation was partially adjusted by automatic addition of the alkaline substrate. After 55 h of incubation, the polymeric glucan, xylan, and arabinan present in the lime-treated straw were hydrolyzed for 55%, 75%, and 80%, respectively. Lactic acid (40.7 g/l) indicated a fermentation efficiency of 81% and a chiral l(+)-lactic acid purity of 97.2%. In total, 711 g lactic acid was produced out of 2,706 g lime-treated straw, representing 43% of the overall theoretical maximum yield. Approximately half of the lactic acid produced was neutralized by fed-batch feeding of lime-treated straw, whereas the remaining half was neutralized during the batch phase with a Ca(OH)2 suspension. Of the lime added during the pretreatment of straw, 61% was used for the neutralization of lactic acid. This is the first demonstration of a process having a combined alkaline pretreatment of lignocellulosic biomass and pH control in fermentation resulting in a significant saving of lime consumption and avoiding the necessity to recycle lime. PMID:18247027

Measurement of process variables in solid-state fermentation of wheat straw using FT-NIR spectroscopy and synergy interval PLS algorithm.

PubMed

Jiang, Hui; Liu, Guohai; Mei, Congli; Yu, Shuang; Xiao, Xiahong; Ding, Yuhan

2012-11-01

The feasibility of rapid determination of the process variables (i.e. pH and moisture content) in solid-state fermentation (SSF) of wheat straw using Fourier transform near infrared (FT-NIR) spectroscopy was studied. Synergy interval partial least squares (siPLS) algorithm was implemented to calibrate regression model. The number of PLS factors and the number of subintervals were optimized simultaneously by cross-validation. The performance of the prediction model was evaluated according to the root mean square error of cross-validation (RMSECV), the root mean square error of prediction (RMSEP) and the correlation coefficient (R). The measurement results of the optimal model were obtained as follows: RMSECV=0.0776, R(c)=0.9777, RMSEP=0.0963, and R(p)=0.9686 for pH model; RMSECV=1.3544% w/w, R(c)=0.8871, RMSEP=1.4946% w/w, and R(p)=0.8684 for moisture content model. Finally, compared with classic PLS and iPLS models, the siPLS model revealed its superior performance. The overall results demonstrate that FT-NIR spectroscopy combined with siPLS algorithm can be used to measure process variables in solid-state fermentation of wheat straw, and NIR spectroscopy technique has a potential to be utilized in SSF industry. Copyright © 2012 Elsevier B.V. All rights reserved.

Measurement of process variables in solid-state fermentation of wheat straw using FT-NIR spectroscopy and synergy interval PLS algorithm

NASA Astrophysics Data System (ADS)

Jiang, Hui; Liu, Guohai; Mei, Congli; Yu, Shuang; Xiao, Xiahong; Ding, Yuhan

2012-11-01

The feasibility of rapid determination of the process variables (i.e. pH and moisture content) in solid-state fermentation (SSF) of wheat straw using Fourier transform near infrared (FT-NIR) spectroscopy was studied. Synergy interval partial least squares (siPLS) algorithm was implemented to calibrate regression model. The number of PLS factors and the number of subintervals were optimized simultaneously by cross-validation. The performance of the prediction model was evaluated according to the root mean square error of cross-validation (RMSECV), the root mean square error of prediction (RMSEP) and the correlation coefficient (R). The measurement results of the optimal model were obtained as follows: RMSECV = 0.0776, Rc = 0.9777, RMSEP = 0.0963, and Rp = 0.9686 for pH model; RMSECV = 1.3544% w/w, Rc = 0.8871, RMSEP = 1.4946% w/w, and Rp = 0.8684 for moisture content model. Finally, compared with classic PLS and iPLS models, the siPLS model revealed its superior performance. The overall results demonstrate that FT-NIR spectroscopy combined with siPLS algorithm can be used to measure process variables in solid-state fermentation of wheat straw, and NIR spectroscopy technique has a potential to be utilized in SSF industry.

One-step, green, and economic synthesis of water-soluble photoluminescent carbon dots by hydrothermal treatment of wheat straw, and their bio-applications in labeling, imaging, and sensing

NASA Astrophysics Data System (ADS)

Yuan, Ming; Zhong, Ruibo; Gao, Haiyang; Li, Wanrong; Yun, Xiaoling; Liu, Jingran; Zhao, Xinmin; Zhao, Guofen; Zhang, Feng

2015-11-01

The use of biomass as renewable and sustainable energy source has attracted the attention of politics and research and development (R&D) facilities around the world. Agricultural straw acts as a typical biowaste, which still needs highly effective recycling to save the biomass urgently at present. Photoluminescent carbon dots (C-dots) are novel biocompatible nanomaterials that have been proved to be produced from many carbon-abundant materials and hold great promise for the modern nanobiomedicine. In order to realize a "one-stone-two-birds" strategy, we report a green, economic, one-pot method in this article for synthesizing photoluminescent C-dots by hydrothermal treatment of wheat straw. Using X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), we show that the as-prepared C-dots are amorphous in structure and are mainly composed of carbon. Their tiny size (<2 nm), combined with the characteristic excitation-dependent relatively bright emission, and robust photostability made the C-dots a potential biocompatible nanomaterial for bio-applications. We have experimentally demonstrated their potential applications in biomedical labeling, imaging, and sensing/detecting. The high yield (∼20%) of C-dots from wheat straw may suggest a new economic strategy for recycling biowaste.

Biodegradation of paddy straw obtained from different geographic locations by means of Phlebia spp. for animal feed.

PubMed

Sharma, Rakesh Kumar; Arora, Daljit Singh

2011-02-01

Various cereal straws are used as feed by supplementing the green forage or other feed stuffs. An experiment was designed to see the effect of different geographic locations and climatological conditions on biochemical constituents, fungal degradation and in vitro digestibility of paddy straw. Paddy straw (PS) obtained from three different geographic locations of India was subjected to solid state fermentation using four white rot fungi i.e. Phlebia brevispora, P. fascicularia, P. floridensis and P. radiata. Changes in the biochemical constituents like water soluble content, hemicellulose, cellulose, lignin, total organic matter, and in vitro digestibility of paddy straw was analyzed over a period of 60 days along with lignocellulolytic enzymes i.e. laccase, xylanase and carboxymethyl cellulase. All the fungi degraded the straw samples and enhanced the in vitro digestibility. The paddy straw, obtained from north western zone (NWZ) suffered a maximum loss (228 g/kg) of lignin by P. radiata, while a maximum enhancement of in vitro digestibility from 185 to 256 g/kg was achieved by P. brevispora, which also caused minimum loss in total organic matter (98 g/kg). In PS obtained from central eastern zone (CEZ) and north eastern zone (NEZ), a maximum amount of lignin (210 and 195 g/kg, respectively) was degraded by P. floridensis and resulted into a respective enhancement of in vitro digestibility from 172 to 246 g/kg and 188 to 264 g/kg. The study demonstrates that geographic locations not only affect the biochemical constituents of paddy straw but the fungal degradation of fibers, their in vitro digestibility and lignocellulolytic enzyme activity of the fungus may also vary.

Feeding value of urea molasses-treated wheat straw ensiled with fresh cattle manure for growing crossbred cattle calves.

PubMed

Sarwar, Muhammad; Shahzad, Muhammad A; Nisa, Mahr U; Afzal, Danish; Sharif, Muhammad; Saddiqi, Hafiz A

2011-03-01

The study was carried out to evaluate the influence of urea plus molasses-treated wheat straw (WS) ensiled with cattle manure (CM) on nutrients intake, their digestibilities, and growth performance of crossbred (Sahiwal × Holstein Friesian) cattle calves. The CM was mixed with ground WS in a ratio of 30:70 on dry matter (DM) basis. The WS-CM mixture treated with urea (4% DM) and molasses (4% DM) was allowed to ferment for 40 days in a cemented pit. Four iso-nitrogenous and iso-energetic fermented wheat straw (FWS)-based experimental diets were formulated. The FWS0, FWS20, FWS30, and FWS40 diets contained 0%, 20%, 30%, and 40% FWS, respectively. Twenty calves (9-10 months of age) were randomly allocated to four dietary treatments in a randomized complete block design, five in each group. Increasing trends for DM, organic matter, crude protein, and neutral detergent fiber intakes by calves were observed with increasing dietary FWS level. Weight gain was significantly different among calves fed different levels of FWS. The highest weight gain (491.8 g/day) was observed in calves fed FWS40 diet, while calves fed FWS0 and FWS20 diets gained 350.0 and 449.6 g/day, respectively. The results from this study imply that the FWS can be added up to 30% in the diet of growing crossbred calves without any detrimental effect on their performance.

The effects of straw or straw-derived gasification biochar applications on soil quality and crop productivity: A farm case study.

PubMed

Hansen, Veronika; Müller-Stöver, Dorette; Imparato, Valentina; Krogh, Paul Henning; Jensen, Lars Stoumann; Dolmer, Anders; Hauggaard-Nielsen, Henrik

2017-01-15

Thermal gasification of straw is a highly efficient technology that produces bioenergy and gasification biochar that can be used as a soil amendment, thereby returning non-renewable nutrients and stable carbon, and securing soil quality and crop productivity. A Danish on-farm field study investigated the impact of traditional straw incorporation vs. straw removal for thermal gasification bioenergy production and the application of straw gasification biochar (GB) on soil quality and crop production. Two rates of GB were applied over three successive years in which the field was cropped with winter wheat (Triticum aestivum L.), winter oilseed rape (Brassica napus L.) and winter wheat, respectively, to assess the potential effects on the soil carbon pool, soil microorganisms, earthworms, soil chemical properties and crop yields. The application of GB did not increase the soil organic carbon content significantly and had no effect on crop yields. The application of straw and GB had a positive effect on the populations of bacteria and protists, but no effect on earthworms. The high rate of GB increased soil exchangeable potassium content and soil pH indicating its potassium bioavailability and liming properties. These results suggest, that recycling GB into agricultural soils has the potential to be developed into a system combining bioenergy generation from agricultural residues and crop production, while maintaining soil quality. However, future studies should be undertaken to assess its long-term effects and to identify the optimum balance between straw removal and biochar application rate. Copyright © 2016. Published by Elsevier Ltd.

Nitrogen-functionalization biochars derived from wheat straws via molten salt synthesis: An efficient adsorbent for atrazine removal.

PubMed

Yang, Fan; Sun, Lili; Xie, Weiling; Jiang, Qun; Gao, Yan; Zhang, Wei; Zhang, Ying

2017-12-31

N-doped porous carbon sheets (NPCS) resulted from wheat straws are fabricated through using molten salts via the carbonization-functionalization progress, which show unique hierarchical structure, large pore volume and high surface area with affluent micropores. Results indicate that there exist many hierarchical pores consisting of the single carbon sheet with ultrathin nature, owing to the template role of molten salt mixtures at high temperature. Such superior structure can bring about desired performance of adsorption capacity of 82.8mg/g and quick adsorption rate of 1.43L/(gh) with an initial concentration of 35mg/L at 25°C. Langmuir and Freundlich models are adopted to interpret the adsorption behavior of atrazine and modified Freundlich and intraparticle diffusion (IPD) models are employed to characterize the dynamics of adsorption. Furthermore, nitrogen-functionalization biochars via molten salt synthesis should be further developed as a one-pot methodology to produce N-doped carbons, opening up a feasible approach for resource utilization of crop straws and other biomass wastes. Copyright © 2017 Elsevier B.V. All rights reserved.

In vitro simulation studies of silica deposition induced by lignin from rice*

PubMed Central

Fang, Jiang-Yu; Ma, Xue-Long

2006-01-01

To reveal the possible mechanism of silica deposition in higher plants, lignin was isolated from rice straw following a modified method to conduct a simulation experiment in vitro. UV and infrared absorption spectra showed that the substance had the unique characteristics of pure lignin. The presence of silicon in the precipitation was revealed by TEM (transmission electron microscopy) with EDXA (energy dispersive X-ray analysis) device. It was found that in the borax solution where lignin precipitation occurred silica-lignin co-precipitation was produced but not in the DMSO solution where lignin was broken into its composition compounds and did not precipitate. This means that it is macromolecular lignin itself but not its compounds that could induce silica deposition in higher plants. PMID:16532527

Black liquor-derived carbonaceous solid acid catalyst for the hydrolysis of pretreated rice straw in ionic liquid.

PubMed

Bai, Chenxi; Zhu, Linfeng; Shen, Feng; Qi, Xinhua

2016-11-01

Lignin-containing black liquor from pretreatment of rice straw by KOH aqueous solution was applied to prepare a carbonaceous solid acid catalyst, in which KOH played dual roles of extracting lignin from rice straw and developing porosity of the carbon material as an activation agent. The synthesized black liquor-derived carbon material was applied in catalytic hydrolysis of the residue solid from the pretreatment of rice straw, which was mainly composed of cellulose and hemicellulose, and showed excellent activity for the production of total reducing sugars (TRS) in ionic liquid, 1-butyl-3-methyl imidazolium chloride. The highest TRS yield of 63.4% was achieved at 140°C for 120min, which was much higher than that obtained from crude rice straw under the same reaction conditions (36.6% TRS yield). Overall, this study provides a renewable strategy for the utilization of all components of lignocellulosic biomass. Copyright © 2016 Elsevier Ltd. All rights reserved.

Expression of Aspergillus niger CAZymes is determined by compositional changes in wheat straw generated by hydrothermal or ionic liquid pretreatments.

PubMed

Daly, Paul; van Munster, Jolanda M; Blythe, Martin J; Ibbett, Roger; Kokolski, Matt; Gaddipati, Sanyasi; Lindquist, Erika; Singan, Vasanth R; Barry, Kerrie W; Lipzen, Anna; Ngan, Chew Yee; Petzold, Christopher J; Chan, Leanne Jade G; Pullan, Steven T; Delmas, Stéphane; Waldron, Paul R; Grigoriev, Igor V; Tucker, Gregory A; Simmons, Blake A; Archer, David B

2017-01-01

The capacity of fungi, such as Aspergillus niger, to degrade lignocellulose is harnessed in biotechnology to generate biofuels and high-value compounds from renewable feedstocks. Most feedstocks are currently pretreated to increase enzymatic digestibility: improving our understanding of the transcriptomic responses of fungi to pretreated lignocellulosic substrates could help to improve the mix of activities and reduce the production costs of commercial lignocellulose saccharifying cocktails. We investigated the responses of A. niger to untreated, ionic liquid and hydrothermally pretreated wheat straw over a 5-day time course using RNA-seq and targeted proteomics. The ionic liquid pretreatment altered the cellulose crystallinity while retaining more of the hemicellulosic sugars than the hydrothermal pretreatment. Ionic liquid pretreatment of straw led to a dynamic induction and repression of genes, which was correlated with the higher levels of pentose sugars saccharified from the ionic liquid-pretreated straw. Hydrothermal pretreatment of straw led to reduced levels of transcripts of genes encoding carbohydrate-active enzymes as well as the derived proteins and enzyme activities. Both pretreatments abolished the expression of a large set of genes encoding pectinolytic enzymes. These reduced levels could be explained by the removal of parts of the lignocellulose by the hydrothermal pretreatment. The time course also facilitated identification of temporally limited gene induction patterns. The presented transcriptomic and biochemical datasets demonstrate that pretreatments caused modifications of the lignocellulose, to both specific structural features as well as the organisation of the overall lignocellulosic structure, that determined A. niger transcript levels. The experimental setup allowed reliable detection of substrate-specific gene expression patterns as well as hitherto non-expressed genes. Our data suggest beneficial effects of using untreated and IL

Expression of Aspergillus niger CAZymes is determined by compositional changes in wheat straw generated by hydrothermal or ionic liquid pretreatments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daly, Paul; van Munster, Jolanda M.; Blythe, Martin J.

The capacity of fungi, such as Aspergillus niger, to degrade lignocellulose is harnessed in biotechnology to generate biofuels and high-value compounds from renewable feedstocks. Most feedstocks are currently pretreated to increase enzymatic digestibility: improving our understanding of the transcriptomic responses of fungi to pretreated lignocellulosic substrates could help to improve the mix of activities and reduce the production costs of commercial lignocellulose saccharifying cocktails. We investigated the responses of A. niger to untreated, ionic liquid and hydrothermally pretreated wheat straw over a 5-day time course using RNA-seq and targeted proteomics. The ionic liquid pretreatment altered the cellulose crystallinity while retainingmore » more of the hemicellulosic sugars than the hydrothermal pretreatment. Ionic liquid pretreatment of straw led to a dynamic induction and repression of genes, which was correlated with the higher levels of pentose sugars saccharified from the ionic liquid-pretreated straw. Hydrothermal pretreatment of straw led to reduced levels of transcripts of genes encoding carbohydrate-active enzymes as well as the derived proteins and enzyme activities. Both pretreatments abolished the expression of a large set of genes encoding pectinolytic enzymes. These reduced levels could be explained by the removal of parts of the lignocellulose by the hydrothermal pretreatment. The time course also facilitated identification of temporally limited gene induction patterns. The presented transcriptomic and biochemical datasets demonstrate that pretreatments caused modifications of the lignocellulose, to both specific structural features as well as the organisation of the overall lignocellulosic structure, that determined A. niger transcript levels. The experimental setup allowed reliable detection of substrate-specific gene expression patterns as well as hitherto non-expressed genes. Our data suggest beneficial effects of using untreated and

Expression of Aspergillus niger CAZymes is determined by compositional changes in wheat straw generated by hydrothermal or ionic liquid pretreatments

DOE PAGES

Daly, Paul; van Munster, Jolanda M.; Blythe, Martin J.; ...

2017-02-07

The capacity of fungi, such as Aspergillus niger, to degrade lignocellulose is harnessed in biotechnology to generate biofuels and high-value compounds from renewable feedstocks. Most feedstocks are currently pretreated to increase enzymatic digestibility: improving our understanding of the transcriptomic responses of fungi to pretreated lignocellulosic substrates could help to improve the mix of activities and reduce the production costs of commercial lignocellulose saccharifying cocktails. We investigated the responses of A. niger to untreated, ionic liquid and hydrothermally pretreated wheat straw over a 5-day time course using RNA-seq and targeted proteomics. The ionic liquid pretreatment altered the cellulose crystallinity while retainingmore » more of the hemicellulosic sugars than the hydrothermal pretreatment. Ionic liquid pretreatment of straw led to a dynamic induction and repression of genes, which was correlated with the higher levels of pentose sugars saccharified from the ionic liquid-pretreated straw. Hydrothermal pretreatment of straw led to reduced levels of transcripts of genes encoding carbohydrate-active enzymes as well as the derived proteins and enzyme activities. Both pretreatments abolished the expression of a large set of genes encoding pectinolytic enzymes. These reduced levels could be explained by the removal of parts of the lignocellulose by the hydrothermal pretreatment. The time course also facilitated identification of temporally limited gene induction patterns. The presented transcriptomic and biochemical datasets demonstrate that pretreatments caused modifications of the lignocellulose, to both specific structural features as well as the organisation of the overall lignocellulosic structure, that determined A. niger transcript levels. The experimental setup allowed reliable detection of substrate-specific gene expression patterns as well as hitherto non-expressed genes. Our data suggest beneficial effects of using untreated and

Cost and greenhouse gas emission tradeoffs of alternative uses of lignin for second generation ethanol

NASA Astrophysics Data System (ADS)

Pourhashem, Ghasideh; Adler, Paul R.; McAloon, Andrew J.; Spatari, Sabrina

2013-06-01

Second generation ethanol bioconversion technologies are under demonstration-scale development for the production of lignocellulosic fuels to meet the US federal Renewable Fuel Standards (RFS2). Bioconversion technology utilizes the fermentable sugars generated from the cellulosic fraction of the feedstock, and most commonly assumes that the lignin fraction may be used as a source of thermal and electrical energy. We examine the life cycle greenhouse gas (GHG) emission and techno-economic cost tradeoffs for alternative uses of the lignin fraction of agricultural residues (corn stover, and wheat and barley straw) produced within a 2000 dry metric ton per day ethanol biorefinery in three locations in the United States. We compare three scenarios in which the lignin is (1) used as a land amendment to replace soil organic carbon (SOC); (2) separated, dried and sold as a coal substitute to produce electricity; and (3) used to produce electricity onsite at the biorefinery. Results from this analysis indicate that for life cycle GHG intensity, amending the lignin to land is lowest among the three ethanol production options (-25 to -2 g CO2e MJ-1), substituting coal with lignin is second lowest (4-32 g CO2e MJ-1), and onsite power generation is highest (36-41 g CO2e MJ-1). Moreover, the onsite power generation case may not meet RFS2 cellulosic fuel requirements given the uncertainty in electricity substitution. Options that use lignin for energy do so at the expense of SOC loss. The lignin-land amendment option has the lowest capital cost among the three options due to lower equipment costs for the biorefinery’s thermal energy needs and use of biogas generated onsite. The need to purchase electricity and uncertain market value of the lignin-land amendment could raise its cost compared to onsite power generation and electricity co-production. However, assuming a market value (50-100/dry Mg) for nutrient and soil carbon replacement in agricultural soils, and potentially

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

NASA Astrophysics Data System (ADS)

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

2013-04-01

The combustion of fossil fuels is responsible for 73% of carbon dioxide emissions into the atmosphere and consequently contributes to global warming. This fact has enormously increased the interest in the development of methods to reduce greenhouse gases. Therefore, the focus is on the production of biofuels from lignocellulosic agricultural residues. The feedstocks used for 2nd generation bioethanol production are lignocellulosic raw materials like different straw types or energy crops like miscanthus sinensis or arundo donax. Lignocellulose consists of hemicellulose (xylose and arabinose), which is bonded to cellulose (glucose) and lignin. Prior to an enzymatic hydrolysis of the polysaccharides and fermentation of the resulting sugars, the lignocelluloses must be pretreated to make the sugar polymers accessible to enzymes. A variety of pretreatment methods are described in the literature: thermophysical, acid-based and alkaline methods.In this study, we examined and compared the most important pretreatment methods: Steam explosion versus acid and alkaline pretreatment. Specific attention was paid to the mass balance, the recovery of C 5 sugars and consumption of chemicals needed for pretreatment. In lab scale experiments, wheat straw was either directly pretreated by steam explosion or by two different protocols. The straw was either soaked in sulfuric acid or in sodium hydroxide solution at different concentrations. For both methods, wheat straw was pretreated at 100°C for 30 minutes. Afterwards, the remaining straw was separated by vacuum filtration from the liquid fraction.The pretreated straw was neutralized, dried and enzymatically hydrolyzed. Finally, the sugar concentrations (glucose, xylose and arabinose) from filtrate and from hydrolysate were determined by HPLC. The recovery of xylose from hemicellulose was about 50% using the sulfuric acid pretreatment and less than 2% using the sodium hydroxide pretreatment. Increasing concentrations of sulfuric acid

Biological pretreatment with a cellobiose dehydrogenase-deficient strain of Trametes versicolor enhances the biofuel potential of canola straw.

PubMed

Canam, Thomas; Town, Jennifer R; Tsang, Adrian; McAllister, Tim A; Dumonceaux, Tim J

2011-11-01

The use of Trametes versicolor as a biological pretreatment for canola straw was explored in the context of biofuel production. Specifically, the effects on the straw of a wild-type strain (52J) and a cellobiose dehydrogenase (CDH)-deficient strain (m4D) were investigated. The xylose and glucose contents of the straw treated with 52J were significantly reduced, while only the xylose content was reduced with m4D treatment. Lignin extractability was greatly improved with fungal treatments compared to untreated straw. Saccharification of the residue of the m4D-treated straw led to a significant increase in proportional glucose yield, which was partially attributed to the lack of cellulose catabolism by m4D. Overall, the results of this study indicate that CDH facilitates cellulose access by T. versicolor. Furthermore, treatment of lignocellulosic material with m4D offers improvements in lignin extractability and saccharification efficacy compared to untreated biomass without loss of substrate due to fungal catabolism. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

Accumulation of biomass and bioenergy in culms of cereals as a factor of straw cutting height

NASA Astrophysics Data System (ADS)

Zając, Tomasz; Synowiec, Agnieszka; Oleksy, Andrzej; Macuda, Jan; Klimek-Kopyra, Agnieszka; Borowiec, Franciszek

2017-04-01

Cereal straw is an important biomass source in Europe. This work assessed: 1) the morphological and energetic characteristics of culms of spring and winter cereals, 2) the energy deposited in the different aboveground parts of cereals, 3) losses of energy due to different cutting heights. The straw of winter and spring cereals was collected from arable fields during the seasons 2009/10 and 2010/11 in southern Poland. Detailed biometric measurements of culms and internodes were performed. The losses of straw biomass and energy were assessed during simulation of cutting the culm at different heights, up to 50 cm. Longer and heavier culms were developed by winter wheat and triticale and oat. Cutting of straw up to 10 cm did not lead to significant losses in straw yield. The total amount of energy in the culms was as follows: triticale > winter wheat > oat > spring wheat > winter barley > spring barley. Cutting the culms above 20 cm led to significant differences in terms of biomass energy between cereal species. The smallest losses of energy were recorded for spring and winter barley. Oat and barley accumulated the highest energy in grains.

Tillage practices and straw-returning methods affect topsoil bacterial community and organic C under a rice-wheat cropping system in central China

NASA Astrophysics Data System (ADS)

Guo, Lijin; Zheng, Shixue; Cao, Cougui; Li, Chengfang

2016-09-01

The objective of this study was to investigate how the relationships between bacterial communities and organic C (SOC) in topsoil (0-5 cm) are affected by tillage practices [conventional intensive tillage (CT) or no-tillage (NT)] and straw-returning methods [crop straw returning (S) or removal (NS)] under a rice-wheat rotation in central China. Soil bacterial communities were determined by high-throughput sequencing technology. After two cycles of annual rice-wheat rotation, compared with CT treatments, NT treatments generally had significantly more bacterial genera and monounsaturated fatty acids/saturated fatty acids (MUFA/STFA), but a decreased gram-positive bacteria/gram-negative bacteria ratio (G+/G-). S treatments had significantly more bacterial genera and MUFA/STFA, but had decreased G+/G- compared with NS treatments. Multivariate analysis revealed that Gemmatimonas, Rudaea, Spingomonas, Pseudomonas, Dyella, Burkholderia, Clostridium, Pseudolabrys, Arcicella and Bacillus were correlated with SOC, and cellulolytic bacteria (Burkholderia, Pseudomonas, Clostridium, Rudaea and Bacillus) and Gemmationas explained 55.3% and 12.4% of the variance in SOC, respectively. Structural equation modeling further indicated that tillage and residue managements affected SOC directly and indirectly through these cellulolytic bacteria and Gemmationas. Our results suggest that Burkholderia, Pseudomonas, Clostridium, Rudaea, Bacillus and Gemmationas help to regulate SOC sequestration in topsoil under tillage and residue systems.

Structural characterization of Chinese quince fruit lignin pretreated with enzymatic hydrolysis.

PubMed

Qin, Zhao; Wang, Xue-De; Liu, Hua-Min; Wang, Dong-Min; Qin, Guang-Yong

2018-08-01

Lignin is an increasingly valuable raw material for industrial, pharmaceutical and the food industries; natural antioxidants are also being used more and more widely. The Chinese quince fruits have an abundance of lignins with antioxidant properties; however, the lignins cannot be isolated by the methods conventionally used on other sources (e.g., wood, straw). In this investigation, multi-enzymatic hydrolytic pretreatments were used to isolate lignins from Chinese quince fruit, and the structures of these multi-enzyme mixture lignin (EML) fractions were then analyzed and compared with conventional cellulolytic enzyme lignin (CEL). EML fractions are structurally similar to CEL fractions except for an increased S/G ratio, greater number of β-O-4 linkages, higher average molecular weight and decreased thermal stability. The EML-2 fraction in particular seemed most representative of the lignins isolated, and it exhibited the highest antioxidant activity in comparison with CEL and other EML fractions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Renewable bio ionic liquids-water mixtures-mediated selective removal of lignin from rice straw: visualization of changes in composition and cell wall structure.

PubMed

Hou, Xue-Dan; Li, Ning; Zong, Min-Hua

2013-07-01

Pretreatment of rice straw by using renewable cholinium amino acids ionic liquids ([Ch][AA] ILs)-water mixtures and the subsequent enzymatic hydrolysis of the residues were conducted in the present work. Of the eight mixtures composed of ILs and water, most were found to be effective for rice straw pretreatment. After pretreatment with 50% ILs-water mixtures, the enzymatic digestion of the lignocellulosic biomass was enhanced significantly, thus leading to satisfactory sugar yields of >80% for glucose and approximately 50% for xylose. To better understand the ILs pretreatment mechanism, confocal laser scanning microscopy combined with immunolabeling and transmission electron microscopy were used to visualize changes in the contents and distribution of two major components--lignin and xylan. The results coupled with changes in chemical structures (infrared spectra) of the substrates indicated occurrence of extensive delignification, especially in cell corner and compound middle lumen of cell walls, which made polysaccharides more accessible to enzymes. This pretreatment process is promising for large-scale application because of the high sugar yields, easy handling, being environmentally benign and highly tolerant to moisture, and significantly reduced cost and energy consumption. Copyright © 2013 Wiley Periodicals, Inc.

Feasibility of co-composting of sewage sludge, spent mushroom substrate and wheat straw.

PubMed

Meng, Liqiang; Li, Weiguang; Zhang, Shumei; Wu, Chuandong; Lv, Longyi

2017-02-01

In this study, the lab-scale co-composting of sewage sludge (SS) with mushroom substrate (SMS) and wheat straw (WS) conducted for 20days was evaluated. The addition of SMS evidently increased CO 2 production and dehydrogenase activity. The combined addition of SMS and WS significantly improved the compost quality in terms of temperature, organic matter degradation and germination index, especially, reduced 21.9% of NH 3 emission. That's because SMS and WS possessed the complementarity of free air space and contained plenty of degradable carbon source. The SMS could create a comfortable environment for the nitrifying bacteria and improve nitrification. The carbohydrates from combined addition of SMS and WS could be utilized by thermophilic microorganisms, stimulate ammonia assimilation and reduce NH 3 emission. These results suggested that adding SMS and WS could not only improve the degradation of organic matter and the quality of compost product, but also stimulate ammonia assimilation and reduce ammonia emission. Copyright © 2016. Published by Elsevier Ltd.

Natural cellulose fibers from soybean straw.

PubMed

Reddy, Narendra; Yang, Yiqi

2009-07-01

This paper reports the development of natural cellulose technical fibers from soybean straw with properties similar to the natural cellulose fibers in current use. About 220 million tons of soybean straw available in the world every year could complement the byproducts of other major food crops as inexpensive, abundant and annually renewable sources for natural cellulose fibers. Using the agricultural byproducts as sources for fibers could help to address the concerns on the future price and availability of both the natural and synthetic fibers in current use and also help to add value to the food crops. A simple alkaline extraction was used to obtain technical fibers from soybean straw and the composition, structure and properties of the fibers was studied. Technical fibers obtained from soybean straw have high cellulose content (85%) but low% crystallinity (47%). The technical fibers have breaking tenacity (2.7 g/den) and breaking elongation (3.9%) higher than those of fibers obtained from wheat straw and sorghum stalk and leaves but lower than that of cotton. Overall, the structure and properties of the technical fibers obtained from soybean straw indicates that the fibers could be suitable for use in textile, composite and other industrial applications.

Evaluation of different water-washing treatments effects on wheat straw combustion properties.

PubMed

Ma, Qiulin; Han, Lujia; Huang, Guangqun

2017-12-01

A series of experiments was conducted to explore the effects of various water-washing solid-liquid ratios (1:50 and 1:10) and the stirring on wheat straw (WS) combustion properties. Comparing different solid-liquid ratio groups, a 16% increment in the higher heating value was obtained for 1:50 groups and only 5% for 1:10 groups relative to the raw material. Moreover, energy was lost 4-26 times greater in 1:10 groups than 1:50 groups. While water-washing reduced the comprehensive combustibility index by 14.89%-32.09%, the index values of washed WS were all higher than 2, indicating good combustion performance. The combustion activation energy of four washed WS were 175, 172, 186, and 176kJ/mol, which were all higher than the 160kJ/mol of WS. The fouling/slagging propensity of washed WS reduced to a lower possibility compared to medium of untreated WS. Overall, the recommended condition for washing WS before combustion is 1:50 ratio without stirring. Copyright © 2017. Published by Elsevier Ltd.

Microscopic Structural Changes in Paddy Straw Pretreated with Trichoderma reesei MTCC 164 and Coriolus versicolor MTCC 138.

PubMed

Phutela, Urmila Gupta; Sahni, Nidhi

2013-06-01

The present study reports the pretreatment of paddy straw by Trichoderma reesei MTCC 164 and Coriolus versicolor MTCC 138 to observe the changes in chemical composition and its correlation with change of surface structure, morphology and porosity of paddy straw. Compared with untreated straw, cellulose decreased by 15.9 and 19.3 % in T. reesei MTCC 164 and C. versicolor MTCC 138 pretreated paddy straw respectively. Lignin content increased by 41.4 % in T. reesei pretreated paddy straw whereas decreased by 19.1 % in C. versicolor pretreated straw. The microscopic structural changes were examined by scanning electron microscopy under reasonable conditions. Results showed that digestibility of paddy straw are increased by treating paddy straw with both the cultures. Both surface area and pore size of treated straw were increased partially due to solubilization of silica components.

Impact of process conditions on the density and durability of wheat, oat, canola, and barley straw briquettes

DOE PAGES

Tumuluru, J. S.; Tabil, L. G.; Song, Y.; ...

2014-10-01

The present study is to understand the impact of process conditions on the quality attributes of wheat oat, barley, and canola straw briquettes. Analysis of variance indicated that briquette moisture content and initial density immediately after compaction and final density after 2 weeks of storage are strong functions of feedstock moisture content and compression pressure, whereas durability rating is influenced by die temperature and feedstock moisture content. Briquettes produced at a low feedstock moisture content of 9 % (w.b.) yielded maximum densities >700 kg/m3 for wheat, oat, canola, and barley straws. Lower feedstock moisture content of <10 % (w.b.) andmore » higher die temperatures >110 °C and compression pressure >10 MPa minimized the briquette moisture content and maximized densities and durability rating based on surface plots observations. Optimal process conditions indicated that a low feedstock moisture content of about 9 % (w.b.), high die temperature of 120–130 °C, medium-to-large hammer mill screen sizes of about 24 to 31.75 mm, and low to high compression pressures of 7.5 to 12.5 MPa minimized briquette moisture content to <8 % (w.b.) and maximized density to >700 kg/m3. Durability rating >90 % is achievable at higher die temperatures of >123 °C, lower to medium feedstock moisture contents of 9 to 12 % (w.b.), low to high compression pressures of 7.5 to 12.5 MPa, and large hammer mill screen size of 31.75 mm, except for canola where a lower compression pressure of 7.5 to 8.5 MPa and a smaller hammer mill screen size of 19 mm for oat maximized the durability rating values.« less

[Effects of different straw recycling and tillage methods on soil respiration and microbial activity].

PubMed

Li, Xiao-sha; Wu, Ning; Liu, Ling; Feng, Yu-peng; Xu, Xu; Han, Hui-fang; Ning, Tang-yuan; Li, Zeng-jia

2015-06-01

To explore the effects of different tillage methods and straw recycling on soil respiration and microbial activity in summer maize field during the winter wheat and summer maize double cropping system, substrate induced respiration method and CO2 release method were used to determine soil microbial biomass carbon, microbial activity, soil respiration, and microbial respiratory quotient. The experiment included 3 tillage methods during the winter wheat growing season, i.e., no-tillage, subsoiling and conventional tillage. Each tillage method was companied with 2 straw management patterns, i.e., straw recycling and no straw. The results indicated that the conservation tillage methods and straw recycling mainly affected 0-10 cm soil layer. Straw recycling could significantly improve the microbial biomass carbon and microbial activity, while decrease microbial respiratory quotient. Straw recycling could improve the soil respiration at both seedling stage and anthesis, however, it could reduce the soil respiration at filling stage, wax ripeness, and harvest stage. Under the same straw application, compared with conventional tillage, the soil respiration and microbial respiratory quotient in both subsoiling and no-tillage were reduced, while the microbial biomass carbon and microbial activity were increased. During the summer maize growing season, soil microbial biomass carbon and microbial activity were increased in straw returning with conservation tillage, while the respiratory quotient was reduced. In 0-10 cm soil layer, compared with conventional tillage, straw recycling with subsoiling and no-tillage significantly increased soil microbial biomass carbon by 95.8% and 74.3%, and increased soil microbial activity by 97.1% and 74.2%, respectively.

Lignin from hydrothermally pretreated grass biomass retards enzymatic cellulose degradation by acting as a physical barrier rather than by inducing nonproductive adsorption of enzymes.

PubMed

Djajadi, Demi T; Jensen, Mads M; Oliveira, Marlene; Jensen, Anders; Thygesen, Lisbeth G; Pinelo, Manuel; Glasius, Marianne; Jørgensen, Henning; Meyer, Anne S

2018-01-01

Lignin is known to hinder efficient enzymatic conversion of lignocellulose in biorefining processes. In particular, nonproductive adsorption of cellulases onto lignin is considered a key mechanism to explain how lignin retards enzymatic cellulose conversion in extended reactions. Lignin-rich residues (LRRs) were prepared via extensive enzymatic cellulose degradation of corn stover ( Zea mays subsp. mays L.), Miscanthus  ×  giganteus stalks (MS) and wheat straw ( Triticum aestivum L.) (WS) samples that each had been hydrothermally pretreated at three severity factors (log R 0 ) of 3.65, 3.83 and 3.97. The LRRs had different residual carbohydrate levels-the highest in MS; the lowest in WS. The residual carbohydrate was not traceable at the surface of the LRRs particles by ATR-FTIR analysis. The chemical properties of the lignin in the LRRs varied across the three types of biomass, but monolignols composition was not affected by the severity factor. When pure cellulose was added to a mixture of LRRs and a commercial cellulolytic enzyme preparation, the rate and extent of glucose release were unaffected by the presence of LRRs regardless of biomass type and severity factor, despite adsorption of the enzymes to the LRRs. Since the surface of the LRRs particles were covered by lignin, the data suggest that the retardation of enzymatic cellulose degradation during extended reaction on lignocellulosic substrates is due to physical blockage of the access of enzymes to the cellulose caused by the gradual accumulation of lignin at the surface of the biomass particles rather than by nonproductive enzyme adsorption. The study suggests that lignin from hydrothermally pretreated grass biomass retards enzymatic cellulose degradation by acting as a physical barrier blocking the access of enzymes to cellulose rather than by inducing retardation through nonproductive adsorption of enzymes.

Model-based characterisation of growth performance and l-lactic acid production with high optical purity by thermophilic Bacillus coagulans in a lignin-supplemented mixed substrate medium.

PubMed

Glaser, Robert; Venus, Joachim

2017-07-25

Three Bacillus coagulans strains were characterised in terms of their ability to grow in lignin-containing fermentation media and to consume the lignocellulose-related sugars glucose, xylose, and arabinose. An optical-density high-throughput screening was used for precharacterisation by means of different mathematical models for comparison (Logistic, Gompertz, Baranyi, Richards & Stannard, and Schnute). The growth response was characterised by the maximum growth rate and lag time. For a comparison of the screening and fermentation results, an unstructured mathematical model was proposed to characterise the lactate production, bacterial growth and substrate consumption. The growth model was then applied to fermentation procedures using wheat straw hydrolysates. The results indicated that the unstructured growth model can be used to evaluate lactate producing fermentation. Under the experimental fermentation conditions, one strain showed the ability to tolerate a high lignin concentration (2.5g/L) but lacked the capacity for sufficient pentose uptake. The lactate yield of the strains that were able to consume all sugar fractions of glucose, xylose and arabinose was ∼83.4%. A photometric measurement at 280nm revealed a dynamic change in alkali-lignin concentrations during lactate producing fermentation. A test of decolourisation of vanillin, ferulic acid, and alkali-lignin samples also showed the decolourisation performance of the B. coagulans strains under study. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Rice straw mulch for post-fire erosion control: assessing non-target effects on vegetation communities

Treesearch

Kristen L. Shive; Becky L. Estes; Angela M. White; Hugh D. Safford; Kevin L. O' Hara; Scott L. Stephens

2017-01-01

Straw mulch is commonly used for post-fire erosion control in severely burned areas but this practice can introduce non-native species, even when certified weed-free straw is used. Rice straw has recently been promoted as an alternative to wheat under the hypothesis that non-native species that are able to grow in a rice field are unlikely to establish in dry forested...

Improvement of high-yield pulp properties by using a small amount of bleached wheat straw pulp.

PubMed

Zhang, Hongjie; He, Zhibin; Ni, Yonghao

2011-02-01

In this study, the potential of using bleached wheat straw pulp (BWSP) was explored to improve the tensile strength of the high-yield pulp (HYP) while preserving its high bulk property. The results showed that with the addition of 5-10% refined BWSP, the HYP tensile strength can be increased by about 10-20% without sacrificing the bulk. Similar results were obtained by adding refined BWSP into a mixed furnish of bleached kraft pulps (BKPs) and HYP. The explanation was that micro fines from refined BWSP can act as binders to improve the HYP interfiber bonding, as a result, the HYP tensile strength can be improved by using a small amount of BWSP, while the HYP bulk is not significantly affected. Copyright © 2010 Elsevier Ltd. All rights reserved.

Systematic Analysis of the Pleurotus ostreatus Laccase Gene (PoLac) Family and Functional Characterization of PoLac2 Involved in the Degradation of Cotton-Straw Lignin.

PubMed

Jiao, Xiaoyu; Li, Guoqing; Wang, Yan; Nie, Fan; Cheng, Xi; Abdullah, Muhammad; Lin, Yi; Cai, Yongping

2018-04-11

Fungal laccases play important roles in the degradation of lignocellulose. Although some PoLac s have been reported in several studies, still no comprehensive bioinformatics study of the LAC family in Pleurotus ostreatus has been reported. In this study, we identified 12 laccase genes in the whole genome sequence of P. ostreatus and their physical characteristics, gene distribution, phylogenic relationships, gene structure, conserved motifs, and cis-elements were also analyzed. The expression patterns of 12 PoLac genes at different developmental stages and under different culture substrates were also analyzed. The results revealed that PoLac2 and PoLac12 may be involved in the degradation of lignin and the formation of the fruiting body, respectively. Subsequently, we overexpressed PoLac2 in P. ostreatus by the Agrobacterium tumefaciens -mediated transformation (ATMT) method. The transformants' laccase activity increased in varying degrees, and the gene expression level of PoLac2 in transformants was 2-8 times higher than that of the wild-type strain. Furthermore, the lignin degradation rate by transgenic fungus over 30 days was 2.36-6.3% higher than that of wild-type. Our data show that overexpression of PoLac2 significantly enhanced the lignin degradation of cotton-straw. To our knowledge, this study is the first report to demonstrate the functions of PoLac2 in P. ostreatus .

Effects of straw and biochar amendments on aggregate stability, soil organic carbon, and enzyme activities in the Loess Plateau, China.

PubMed

Zhang, Man; Cheng, Gong; Feng, Hao; Sun, Benhua; Zhao, Ying; Chen, Haixin; Chen, Jing; Dyck, Miles; Wang, Xudong; Zhang, Jianguo; Zhang, Afeng

2017-04-01

Soil from the Loess Plateau of China is typically low in organic carbon and generally has poor aggregate stability. Application of organic amendments to these soils could help to increase and sustain soil organic matter levels and thus to enhance soil aggregate stability. A field experiment was carried out to evaluate the effect of the application of wheat straw and wheat straw-derived biochar (pyrolyzed at 350-550 °C) amendments on soil aggregate stability, soil organic carbon (SOC), and enzyme activities in a representative Chinese Loess soil during summer maize and winter wheat growing season from 2013 to 2015. Five treatments were set up as follows: no fertilization (CK), application of inorganic fertilizer (N), wheat straw applied at 8 t ha -1 with inorganic fertilizer (S8), and wheat straw-derived biochar applied at 8 t ha -1 (B8) and 16 t ha -1 (B16) with inorganic fertilizer, respectively. Compared to the N treatment, straw and straw-derived biochar amendments significantly increased SOC (by 33.7-79.6%), microbial biomass carbon (by 18.9-46.5%), and microbial biomass nitrogen (by 8.3-38.2%), while total nitrogen (TN) only increased significantly in the B16 plot (by 24.1%). The 8 t ha -1 straw and biochar applications had no significant effects on soil aggregation, but a significant increase in soil macro-aggregates (>2 mm) (by 105.8%) was observed in the B16 treatment. The concentrations of aggregate-associated SOC increased by 40.4-105.8% in macro-aggregates (>2 mm) under straw and biochar amendments relative to the N treatment. No significant differences in invertase and alkaline phosphatase activity were detected among different treatments. However, urease activity was greater in the biochar treatment than the straw treatment, indicating that biochar amendment improved the transformation of nitrogen in the soil. The carbon pool index and carbon management index were increased with straw and biochar amendments, especially in the B16 treatment

Ethanol/water pulps from sugar cane straw and their biobleaching with xylanase from Bacillus pumilus.

PubMed

Moriya, Regina Y; Gonçalves, Adilson R; Duarte, Marta C T

2007-04-01

The influence of independent variables (temperature and time) on the cooking of sugar cane straw with ethanol/water mixtures was studied to determine operating conditions that obtain pulp with high cellulose contents and a low lignin content. An experimental 2(2) design was applied for temperatures of 185 and 215 degrees C, and time of 1 and 2.5 h with the ethanol/water mixture concentration and constant straw-to-solvent ratio. The system was scaled-up at 200 degrees C cooking temperature for 2 h with 50% ethanol-water concentration, and 1:10 (w/v) straw-to-solvent ratio to obtain a pulp with 3.14 cP viscosity, 58.09 kappa-number, and the chemical composition of the pulps were 3.2% pentosan and 31.5% lignin. Xylanase from Bacillus pumilus was then applied at a loading of 5-150 IU/g dry pulp in the sugar cane straw ethanol/water pulp at 50 degrees C for 2 and 20 h. To ethanol/water pulps, the best enzyme dosage was found to be 20 IU/g dry pulp at 20 h, and a high enzyme dosage of 150 IU/g dry pulp did not decrease the kappa-number of the pulp.

Reduced phenylalanine ammonia-lyase and tyrosine ammonia-lyase activities and lignin synthesis in wheat grown under low pressure sodium lamps

NASA Technical Reports Server (NTRS)

Guerra, D.; Anderson, A. J.; Salisbury, F. B.

1985-01-01

Wheat (Triticum aestivum L. cv Fremont) grown in hydroponic culture under 24-hour continuous irradiation at 560 to 580 micromoles per square meter per second from either metalhalide (MH), high pressure sodium (HPS), or low pressure sodium (LPS) lamps reached maturity in 70 days. Grain yields were similar under all three lamps, although LPS-grown plants lodged at maturity. Phenylalanine ammonia-lyase (PAL) and a tyrosine ammonia lyase (TAL) with lesser activity were detected in all extracts of leaf, inflorescence, and stem. Ammonia-lyase activities increased with age of the plant, and plants grown under the LPS lamp displayed PAL and TAL activities lower than wheat cultured under MH and HPS radiation. Greenhouse solar-grown wheat had the highest PAL and TAL activities. Lignin content of LPS-grown wheat was also significantly reduced from that of plants grown under MH or HPS lamps or in the greenhouse, showing a correlation with the reduced PAL and TAL activities. Ratios of far red-absorbing phytochrome to total phytochrome were similar for all three lamps, but the data do not yet warrant a conclusion about specific wavelengths missing from the LPS lamps that might have induced PAL and TAL activities in plants under the other lamps.

Dissecting the effect of chemical additives on the enzymatic hydrolysis of pretreated wheat straw.

PubMed

Monschein, Mareike; Reisinger, Christoph; Nidetzky, Bernd

2014-10-01

Chemical additives were examined for ability to increase the enzymatic hydrolysis of thermo-acidically pretreated wheat straw by Trichoderma reesei cellulase at 50 °C. Semi-empirical descriptors derived from the hydrolysis time courses were applied to compare influence of these additives on lignocellulose bioconversion on a kinetic level, presenting a novel view on their mechanism of action. Focus was on rate retardation during hydrolysis, substrate conversion and enzyme adsorption. PEG 8000 enabled a reduction of enzyme loading by 50% while retaining the same conversion of 67% after 24h. For the first time, a beneficial effect of urea is reported, increasing the final substrate conversion after 48 h by 16%. The cationic surfactant cetyl-trimethylammonium bromide (CTAB) enhanced the hydrolysis rate at extended reaction time (rlim) by 34% and reduced reaction time by 28%. A combination of PEG 8000 and urea increased sugar release more than additives used individually. Copyright © 2014 Elsevier Ltd. All rights reserved.

Cell-wall architecture and lignin composition of wheat developed in a microgravity environment.

PubMed

Levine, L H; Heyenga, A G; Levine, H G; Choi, J; Davin, L B; Krikorian, A D; Lewis, N G

2001-07-01

The microgravity environment encountered during space-flight has long been considered to affect plant growth and developmental processes, including cell wall biopolymer composition and content. As a prelude to studying how microgravity is perceived - and acted upon - by plants, it was first instructive to investigate what gross effects on plant growth and development occurred in microgravity. Thus, wheat seedlings were exposed to microgravity on board the space shuttle Discovery (STS-51) for a 10 day duration, and these specimens were compared with their counterparts grown on Earth under the same conditions (e.g. controls). First, the primary roots of the wheat that developed under both microgravity and 1 g on Earth were examined to assess the role of gravity on cellulose microfibril (CMF) organization and secondary wall thickening patterns. Using a quick freeze/deep etch technique, this revealed that the cell wall CMFs of the space-grown wheat maintained the same organization as their 1 g-grown counterparts. That is, in all instances, CMFs were randomly interwoven with each other in the outermost layers (farthest removed from the plasma membrane), and parallel to each other within the individual strata immediately adjacent to the plasma membranes. The CMF angle in the innermost stratum relative to the immediately adjacent stratum was ca 80 degrees in both the space and Earth-grown plants. Second, all plants grown in microgravity had roots that grew downwards into the agar; they did not display "wandering" and upward growth as previously reported by others. Third, the space-grown wheat also developed normal protoxylem and metaxylem vessel elements with secondary thickening patterns ranging from spiral to regular pit to reticulate thickenings. Fourthly, both the space- and Earth-grown plants were essentially of the same size and height, and their lignin analyses revealed no substantial differences in their amounts and composition regardless of the gravitational

Cell-wall architecture and lignin composition of wheat developed in a microgravity environment

NASA Technical Reports Server (NTRS)

Levine, L. H.; Heyenga, A. G.; Levine, H. G.; Choi, J.; Davin, L. B.; Krikorian, A. D.; Lewis, N. G.; Sager, J. C. (Principal Investigator)

2001-01-01

The microgravity environment encountered during space-flight has long been considered to affect plant growth and developmental processes, including cell wall biopolymer composition and content. As a prelude to studying how microgravity is perceived - and acted upon - by plants, it was first instructive to investigate what gross effects on plant growth and development occurred in microgravity. Thus, wheat seedlings were exposed to microgravity on board the space shuttle Discovery (STS-51) for a 10 day duration, and these specimens were compared with their counterparts grown on Earth under the same conditions (e.g. controls). First, the primary roots of the wheat that developed under both microgravity and 1 g on Earth were examined to assess the role of gravity on cellulose microfibril (CMF) organization and secondary wall thickening patterns. Using a quick freeze/deep etch technique, this revealed that the cell wall CMFs of the space-grown wheat maintained the same organization as their 1 g-grown counterparts. That is, in all instances, CMFs were randomly interwoven with each other in the outermost layers (farthest removed from the plasma membrane), and parallel to each other within the individual strata immediately adjacent to the plasma membranes. The CMF angle in the innermost stratum relative to the immediately adjacent stratum was ca 80 degrees in both the space and Earth-grown plants. Second, all plants grown in microgravity had roots that grew downwards into the agar; they did not display "wandering" and upward growth as previously reported by others. Third, the space-grown wheat also developed normal protoxylem and metaxylem vessel elements with secondary thickening patterns ranging from spiral to regular pit to reticulate thickenings. Fourthly, both the space- and Earth-grown plants were essentially of the same size and height, and their lignin analyses revealed no substantial differences in their amounts and composition regardless of the gravitational

Physical Characterization of Natural Straw Fibers as Aggregates for Construction Materials Applications

PubMed Central

Bouasker, Marwen; Belayachi, Naima; Hoxha, Dashnor; Al-Mukhtar, Muzahim

2014-01-01

The aim of this paper is to find out new alternative materials that respond to sustainable development criteria. For this purpose, an original utilization of straw for the design of lightweight aggregate concretes is proposed. Four types of straw were used: three wheat straws and a barley straw. In the present study, the morphology and the porosity of the different straw aggregates was studied by SEM in order to understand their effects on the capillary structure and the hygroscopic behavior. The physical properties such as sorption-desorption isotherms, water absorption coefficient, pH, electrical conductivity and thermo-gravimetric analysis were also studied. As a result, it has been found that this new vegetable material has a very low bulk density, a high water absorption capacity and an excellent hydric regulator. The introduction of the straw in the water tends to make the environment more basic; this observation can slow carbonation of the binder matrix in the presence of the straw. PMID:28788605

Assessment of some straw-derived materials for reducing the leaching potential of Metribuzin residues in the soil

NASA Astrophysics Data System (ADS)

Cara, Irina Gabriela; Trincă, Lucia Carmen; Trofin, Alina Elena; Cazacu, Ana; Ţopa, Denis; Peptu, Cătălina Anişoara; Jităreanu, Gerard

2015-12-01

Biomass (straw waste) can be used as raw to obtain materials for herbicide removal from wastewater. These by-products have some important advantages, being environmentally friendly, easily available, presenting low costs, and requiring little processing to increase their adsorptive capacity. In the present study, some materials derived from agricultural waste (wheat, corn and soybean straw) were investigated as potential adsorbents for metribuzin removal from aqueous solutions. The straw wastes were processed by grinding, mineralisation (850 °C) and KOH activation in order to improve their functional surface activity. The materials surface characteristics were investigated by scanning electron microscopy, energy dispersive X-ray spectroscopy and atomic force microscopy. The adsorbents capacity was evaluated using batch sorption tests and liquid chromatography coupled with mass spectrometry for herbicide determination. For adsorption isotherms, the equilibrium time considered was 3 h. The experimental adsorption data were modelled by Freundlich and Langmuir models. The activated straw and ash-derived materials from wheat, corn and soybean increased the adsorption capacity of metribuzin with an asymmetrical behaviour. Overall, our results sustain that activated ash-derived from straw and activated straw materials can be a valuable solution for reducing the leaching potential of metribuzin through soil.

[Effects of different fertilization regimes on weed communities in wheat fields under rice-wheat cropping system].

PubMed

Yuan, Fang; Li, Yong; Li, Fen-hua; Sun, Guo-jun; Han, Min; Zhang, Hai-yan; Ji, Zhong; Wu, Chen-yu

2016-01-01

To reveal the effects of different fertilization regimes on weed communities in wheat fields under a rice-wheat rotation system, a survey was conducted before wheat harvest in 2014 after a 4-year long-term recurrent fertilization scheme. Weed species types, density, height and diversity index under different fertilization and straw-returning schemes in wheat fields were studied and complemented with a canonical correspondence analysis on weed community distribution and soil nutrient factors. Twenty weed species were recorded among 36 wheat fields belonging to 19 genera and 11 families. Beckmannia syzigachne, Hemistepta lyrata, Malachium aquaticum and Cnidium monnieri were widely distributed throughout the sampled area. Long-term fertilization appeared to reduce weed species richness and density, particularly for broadleaf weeds, but increased weed height. Diversity and evenness indices of weed communities were lower and dominance indices were higher in fields where chemical fertilizers were applied alone or combined with organic fertilizers, especially, where organic-inorganic compound fertilizer was used, in which it readily caused the outbreak of a dominant species and severe damage. Conversely, diversity and evenness indices of weed communities were higher and dominance indices were lower when the straw was returned to the field combined with chemical or organic fertilizers, in which weed community structures were complex and stable with lower weed density. Under these conditions weeds only caused slight reduction of wheat growth.

Open burning of rice, corn and wheat straws: primary emissions, photochemical aging, and secondary organic aerosol formation

NASA Astrophysics Data System (ADS)

Fang, Zheng; Deng, Wei; Zhang, Yanli; Ding, Xiang; Tang, Mingjin; Liu, Tengyu; Hu, Qihou; Zhu, Ming; Wang, Zhaoyi; Yang, Weiqiang; Huang, Zhonghui; Song, Wei; Bi, Xinhui; Chen, Jianmin; Sun, Yele; George, Christian; Wang, Xinming

2017-12-01

Agricultural residues are among the most abundant biomass burned globally, especially in China. However, there is little information on primary emissions and photochemical evolution of agricultural residue burning. In this study, indoor chamber experiments were conducted to investigate primary emissions from open burning of rice, corn and wheat straws and their photochemical aging as well. Emission factors of NOx, NH3, SO2, 67 non-methane hydrocarbons (NMHCs), particulate matter (PM), organic aerosol (OA) and black carbon (BC) under ambient dilution conditions were determined. Olefins accounted for > 50 % of the total speciated NMHCs emission (2.47 to 5.04 g kg-1), indicating high ozone formation potential of straw burning emissions. Emission factors of PM (3.73 to 6.36 g kg-1) and primary organic carbon (POC, 2.05 to 4.11 gC kg-1), measured at dilution ratios of 1300 to 4000, were lower than those reported in previous studies at low dilution ratios, probably due to the evaporation of semi-volatile organic compounds under high dilution conditions. After photochemical aging with an OH exposure range of (1.97-4.97) × 1010 molecule cm-3 s in the chamber, large amounts of secondary organic aerosol (SOA) were produced with OA mass enhancement ratios (the mass ratio of total OA to primary OA) of 2.4-7.6. The 20 known precursors could only explain 5.0-27.3 % of the observed SOA mass, suggesting that the major precursors of SOA formed from open straw burning remain unidentified. Aerosol mass spectrometry (AMS) signaled that the aged OA contained less hydrocarbons but more oxygen- and nitrogen-containing compounds than primary OA, and carbon oxidation state (OSc) calculated with AMS resolved O / C and H / C ratios increased linearly (p < 0.001) with OH exposure with quite similar slopes.

Metabolic fate and distribution of [{sup 14}C]1,3-dichloropropene in carrot, lettuce, radish, tomato, and wheat

DOE Office of Scientific and Technical Information (OSTI.GOV)

Barnkow, D.E.; Byrne, S.L.; Huskin, M.A.

1996-10-01

This study examined the nature of the radioactive residue in carrot, lettuce, radish, tomato, and wheat grown in soil treated with uniformly {sup 14}C-labeled cis- and trans-1,3-dichloropropene (1,3-D). Each crop was grown in soil treated at or above the maximum use rate. Carrot root and top, lettuce, radish root and top, tomato fruit and vine, and wheat forage, straw and grain were harvested, processed, and analyzed. The {sup 14}C residues were subjected to sequential extraction with diethyl ether and aqueous acetonitrile. The residues that remained were subjected to extraction, fractionation, and hydrolysis with buffer, enzymes, acid, alkali, and strong oxidizingmore » agents. Analyses of the solubilized residues demonstrated that no detectable parent, 1,3-D, or the putative metabolites 3-chloroallyl alcohol and 3-chloroacrylic acid were present. The components of the extractable residue included most major plant constituents (i.e., protein, pigments, organic acids, sucrose, cellulose, and lignin). Thus, natural incorporation of the {sup 14}C-label into natural plant biochemicals is demonstrated.« less

Characterization and Comparison of Fast Pyrolysis Bio-oils from Pinewood, Rapeseed Cake, and Wheat Straw Using 13C NMR and Comprehensive GC × GC.

PubMed

Negahdar, Leila; Gonzalez-Quiroga, Arturo; Otyuskaya, Daria; Toraman, Hilal E; Liu, Li; Jastrzebski, Johann T B H; Van Geem, Kevin M; Marin, Guy B; Thybaut, Joris W; Weckhuysen, Bert M

2016-09-06

Fast pyrolysis bio-oils are feasible energy carriers and a potential source of chemicals. Detailed characterization of bio-oils is essential to further develop its potential use. In this study, quantitative 13 C nuclear magnetic resonance ( 13 C NMR) combined with comprehensive two-dimensional gas chromatography (GC × GC) was used to characterize fast pyrolysis bio-oils originated from pinewood, wheat straw, and rapeseed cake. The combination of both techniques provided new information on the chemical composition of bio-oils for further upgrading. 13 C NMR analysis indicated that pinewood-based bio-oil contained mostly methoxy/hydroxyl (≈30%) and carbohydrate (≈27%) carbons; wheat straw bio-oil showed to have high amount of alkyl (≈35%) and aromatic (≈30%) carbons, while rapeseed cake-based bio-oil had great portions of alkyl carbons (≈82%). More than 200 compounds were identified and quantified using GC × GC coupled to a flame ionization detector (FID) and a time of flight mass spectrometer (TOF-MS). Nonaromatics were the most abundant and comprised about 50% of the total mass of compounds identified and quantified via GC × GC. In addition, this analytical approach allowed the quantification of high value-added phenolic compounds, as well as of low molecular weight carboxylic acids and aldehydes, which exacerbate the unstable and corrosive character of the bio-oil.

Characterization and Comparison of Fast Pyrolysis Bio-oils from Pinewood, Rapeseed Cake, and Wheat Straw Using 13C NMR and Comprehensive GC × GC

PubMed Central

2016-01-01

Fast pyrolysis bio-oils are feasible energy carriers and a potential source of chemicals. Detailed characterization of bio-oils is essential to further develop its potential use. In this study, quantitative 13C nuclear magnetic resonance (13C NMR) combined with comprehensive two-dimensional gas chromatography (GC × GC) was used to characterize fast pyrolysis bio-oils originated from pinewood, wheat straw, and rapeseed cake. The combination of both techniques provided new information on the chemical composition of bio-oils for further upgrading. 13C NMR analysis indicated that pinewood-based bio-oil contained mostly methoxy/hydroxyl (≈30%) and carbohydrate (≈27%) carbons; wheat straw bio-oil showed to have high amount of alkyl (≈35%) and aromatic (≈30%) carbons, while rapeseed cake-based bio-oil had great portions of alkyl carbons (≈82%). More than 200 compounds were identified and quantified using GC × GC coupled to a flame ionization detector (FID) and a time of flight mass spectrometer (TOF-MS). Nonaromatics were the most abundant and comprised about 50% of the total mass of compounds identified and quantified via GC × GC. In addition, this analytical approach allowed the quantification of high value-added phenolic compounds, as well as of low molecular weight carboxylic acids and aldehydes, which exacerbate the unstable and corrosive character of the bio-oil. PMID:27668136

Chemical characterization and oxidative potential of particles emitted from open burning of cereal straws and rice husk under flaming and smoldering conditions

NASA Astrophysics Data System (ADS)

Fushimi, Akihiro; Saitoh, Katsumi; Hayashi, Kentaro; Ono, Keisuke; Fujitani, Yuji; Villalobos, Ana M.; Shelton, Brandon R.; Takami, Akinori; Tanabe, Kiyoshi; Schauer, James J.

2017-08-01

Open burning of crop residue is a major source of atmospheric fine particle emissions. We burned crop residues (rice straws, barley straws, wheat straws, and rice husks produced in Japan) in an outdoor chamber and measured particle mass, composition (elemental carbon: EC, organic carbon: OC, ions, elements, and organic species), and oxidative potential in the exhausts. The fine particulate emission factors from the literature were within the range of our values for rice straws but were 1.4-1.9 and 0.34-0.44 times higher than our measured values for barley straw and wheat straw, respectively. For rice husks and wheat straws, which typically lead to combustion conditions that are relatively mild, the EC content of the particles was less than 5%. Levoglucosan seems more suitable as a biomass burning marker than K+, since levoglucosan/OC ratios were more stable than K+/particulate mass ratios among crop species. Stigmasterol and β-sitosterol could also be used as markers of biomass burning with levoglucosan or instead of levoglucosan. Correlation analysis between chemical composition and combustion condition suggests that hot or flaming combustions enhance EC, K+, Cl- and polycyclic aromatic hydrocarbons emissions, while low-temperature or smoldering combustions enhance levoglucosan and water-soluble organic carbon emissions. Oxidative potential, measured with macrophage-based reactive oxygen species (ROS) assay and dithiothreitol (DTT) assay, of open burning fine particles per particulate mass as well as fine particulate emission factors were the highest for wheat straws and second highest for rice husks and rice straws. Oxidative potential per particulate mass was in the lower range of vehicle exhaust and atmosphere. These results suggest that the contribution of open burning is relatively small to the oxidative potential of atmospheric particles. In addition, oxidative potential (both ROS and DTT activities) correlated well with water-insoluble organic species

Enzymatic saccharification of pretreated wheat straw: comparison of solids-recycling, sequential hydrolysis and batch hydrolysis.

PubMed

Pihlajaniemi, Ville; Sipponen, Satu; Sipponen, Mika H; Pastinen, Ossi; Laakso, Simo

2014-02-01

In the enzymatic hydrolysis of lignocellulose materials, the recycling of the solid residue has previously been considered within the context of enzyme recycling. In this study, a steady state investigation of a solids-recycling process was made with pretreated wheat straw and compared to sequential and batch hydrolysis at constant reaction times, substrate feed and liquid and enzyme consumption. Compared to batch hydrolysis, the recycling and sequential processes showed roughly equal hydrolysis yields, while the volumetric productivity was significantly increased. In the 72h process the improvement was 90% due to an increased reaction consistency, while the solids feed was 16% of the total process constituents. The improvement resulted primarily from product removal, which was equally efficient in solids-recycling and sequential hydrolysis processes. No evidence of accumulation of enzymes beyond the accumulation of the substrate was found in recycling. A mathematical model of solids-recycling was constructed, based on a geometrical series. Copyright © 2013 Elsevier Ltd. All rights reserved.

A multi-substrate approach for functional metagenomics-based screening for (hemi)cellulases in two wheat straw-degrading microbial consortia unveils novel thermoalkaliphilic enzymes.

PubMed

Maruthamuthu, Mukil; Jiménez, Diego Javier; Stevens, Patricia; van Elsas, Jan Dirk

2016-01-28

Functional metagenomics is a promising strategy for the exploration of the biocatalytic potential of microbiomes in order to uncover novel enzymes for industrial processes (e.g. biorefining or bleaching pulp). Most current methodologies used to screen for enzymes involved in plant biomass degradation are based on the use of single substrates. Moreover, highly diverse environments are used as metagenomic sources. However, such methods suffer from low hit rates of positive clones and hence the discovery of novel enzymatic activities from metagenomes has been hampered. Here, we constructed fosmid libraries from two wheat straw-degrading microbial consortia, denoted RWS (bred on untreated wheat straw) and TWS (bred on heat-treated wheat straw). Approximately 22,000 clones from each library were screened for (hemi)cellulose-degrading enzymes using a multi-chromogenic substrate approach. The screens yielded 71 positive clones for both libraries, giving hit rates of 1:440 and 1:1,047 for RWS and TWS, respectively. Seven clones (NT2-2, T5-5, NT18-17, T4-1, 10BT, NT18-21 and T17-2) were selected for sequence analyses. Their inserts revealed the presence of 18 genes encoding enzymes belonging to twelve different glycosyl hydrolase families (GH2, GH3, GH13, GH17, GH20, GH27, GH32, GH39, GH53, GH58, GH65 and GH109). These encompassed several carbohydrate-active gene clusters traceable mainly to Klebsiella related species. Detailed functional analyses showed that clone NT2-2 (containing a beta-galactosidase of ~116 kDa) had highest enzymatic activity at 55 °C and pH 9.0. Additionally, clone T5-5 (containing a beta-xylosidase of ~86 kDa) showed > 90% of enzymatic activity at 55 °C and pH 10.0. This study employed a high-throughput method for rapid screening of fosmid metagenomic libraries for (hemi)cellulose-degrading enzymes. The approach, consisting of screens on multi-substrates coupled to further analyses, revealed high hit rates, as compared with recent other studies. Two

Characterization of a Novel Dye-Decolorizing Peroxidase (DyP)-Type Enzyme from Irpex lacteus and Its Application in Enzymatic Hydrolysis of Wheat Straw

PubMed Central

Salvachúa, Davinia; Prieto, Alicia

2013-01-01

Irpex lacteus is a white rot basidiomycete proposed for a wide spectrum of biotechnological applications which presents an interesting, but still scarcely known, enzymatic oxidative system. Among these enzymes, the production, purification, and identification of a new dye-decolorizing peroxidase (DyP)-type enzyme, as well as its physico-chemical, spectroscopic, and catalytic properties, are described in the current work. According to its N-terminal sequence and peptide mass fingerprinting analyses, I. lacteus DyP showed high homology (>95%) with the hypothetical (not isolated or characterized) protein cpop21 from an unidentified species of the family Polyporaceae. The enzyme had a low optimal pH, was very stable to acid pH and temperature, and showed improved activity and stability at high H2O2 concentrations compared to other peroxidases. Other attractive features of I. lacteus DyP were its high catalytic efficiency oxidizing the recalcitrant anthraquinone and azo dyes assayed (kcat/Km of 1.6 × 106 s-1 M-1) and its ability to oxidize nonphenolic aromatic compounds like veratryl alcohol. In addition, the effect of this DyP during the enzymatic hydrolysis of wheat straw was checked. The results suggest that I. lacteus DyP displayed a synergistic action with cellulases during the hydrolysis of wheat straw, increasing significantly the fermentable glucose recoveries from this substrate. These data show a promising biotechnological potential for this enzyme. PMID:23666335

Structural features of reconstituted wheat wax films

PubMed Central

Pambou, Elias; Li, Zongyi; Campana, Mario; Hughes, Arwel; Clifton, Luke; Gutfreund, Philipp; Foundling, Jill

2016-01-01

Cuticular waxes are essential for the well-being of all plants, from controlling the transport of water and nutrients across the plant surface to protecting them against external environmental attacks. Despite their significance, our current understanding regarding the structure and function of the wax film is limited. In this work, we have formed representative reconstituted wax film models of controlled thicknesses that facilitated an ex vivo study of plant cuticular wax film properties by neutron reflection (NR). Triticum aestivum L. (wheat) waxes were extracted from two different wheat straw samples, using two distinct extraction methods. Waxes extracted from harvested field-grown wheat straw using supercritical CO2 are compared with waxes extracted from laboratory-grown wheat straw via wax dissolution by chloroform rinsing. Wax films were produced by spin-coating the two extracts onto silicon substrates. Atomic force microscopy and cryo-scanning electron microscopy imaging revealed that the two reconstituted wax film models are ultrathin and porous with characteristic nanoscale extrusions on the outer surface, mimicking the structure of epicuticular waxes found upon adaxial wheat leaf surfaces. On the basis of solid–liquid and solid–air NR and ellipsometric measurements, these wax films could be modelled into two representative layers, with the diffuse underlying layer fitted with thicknesses ranging from approximately 65 to 70 Å, whereas the surface extrusion region reached heights exceeding 200 Å. Moisture-controlled NR measurements indicated that water penetrated extensively into the wax films measured under saturated humidity and under water, causing them to hydrate and swell significantly. These studies have thus provided a useful structural basis that underlies the function of the epicuticular waxes in controlling the water transport of crops. PMID:27466439

Enhancing saccharification of wheat straw by mixing enzymes from genetically-modified Trichoderma reesei and Aspergillus niger.

PubMed

Jiang, Yanping; Duarte, Alexandra Vivas; van den Brink, Joost; Wiebenga, Ad; Zou, Gen; Wang, Chengshu; de Vries, Ronald P; Zhou, Zhihua; Benoit, Isabelle

2016-01-01

To increase the efficiency of enzymatic hydrolysis for plant biomass conversion into renewable biofuel and chemicals. By overexpressing the point mutation A824 V transcriptional activator Xyr1 in Trichoderma reesei, carboxymethyl cellulase, cellobiosidase and β-D-glucosidase activities of the best mutant were increased from 1.8 IU/ml, 0.1 IU/ml and 0.05 IU/ml to 4.8 IU/ml, 0.4 IU/ml and 0.3 IU/ml, respectively. The sugar yield of wheat straw saccharification by combining enzymes from this mutant and the Aspergillus niger genetically modified strain ΔcreA/xlnR c/araR c was improved up to 7.5 mg/ml, a 229 % increase compared to the combination of wild type strains. Mixing enzymes from T. reesei and A. niger combined with the genetic modification of transcription factors is a promising strategy to increase saccharification efficiency.

Trichoderma Reesei single cell protein production from rice straw pulp in solid state fermentation

NASA Astrophysics Data System (ADS)

Zaki, M.; Said, S. D.

2018-04-01

The dependency on fish meal as a major protein source for animal feed can lead toit priceinstability in line with the increasing in meat production and consumption in Indonesia. In order todeal with this problem, an effort to produce an alternative protein sources production is needed. This scenario is possible due to the abundantavailability of agricultural residues such as rice straw whichcould be utilized as substrate for production of single cell proteins as an alternative proteinsource. This work investigated the potential utilization of rice straw pulp and urea mixture as substrate for the production of local Trichoderma reesei single cell protein in solid state fermentation system. Some parameters have been analyzed to evaluate the effect of ratio of rice straw pulp to urea on mixed single cell protein biomass (mixed SCP biomass) composition, such as total crude protein (analyzed by kjedhal method) and lignin content (TAPPI method).The results showed that crude protein content in mixed SCP biomassincreases with the increasing in fermentation time, otherwise it decreases with the increasing insubstrate carbon to nitrogen (C/N) ratio. Residual lignin content in mixed SCP biomass decreases from 7% to 0.63% during fermentationproceeded of 21 days. The highest crude protein content in mixed SCP biomasswas obtained at substrate C/N ratio 20:1 of 25%.

[Effects of adding straw carbon source to root knot nematode diseased soil on soil microbial biomass and protozoa abundance].

PubMed

Zhang, Si-Hui; Lian, Jian-Hong; Cao, Zhi-Ping; Zhao, Li

2013-06-01

A field experiment with successive planting of tomato was conducted to study the effects of adding different amounts of winter wheat straw (2.08 g x kg(-1), 1N; 4.16 g x kg(-1), 2N; and 8.32 g x kg(-1), 4N) to the soil seriously suffered from root knot nematode disease on the soil microbial biomass and protozoa abundance. Adding straw carbon source had significant effects on the contents of soil microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) and the abundance of soil protozoa, which all decreased in the order of 4N > 2N > 1N > CK. The community structure of soil protozoa also changed significantly under straw addition. In the treatments with straw addition, the average proportion of fagellate, amoeba, and ciliates accounted for 36.0%, 59.5%, and 4.5% of the total protozoa, respectively. Under the same adding amounts of wheat straw, there was an increase in the soil MBC and MBN contents, MBC/MBN ratio, and protozoa abundance with increasing cultivation period.

The use of steam explosion to increase the nutrition available from rice straw.

PubMed

Li, Bin; Chen, Kunjie; Gao, Xiang; Zhao, Chao; Shao, Qianjun; Sun, Qian; Li, Hua

2015-01-01

In the present study, rice straw was pretreated using steam-explosion (ST) technique to improve the enzymatic hydrolysis of potential reducing sugars for feed utilization. The response surface methodology based on central composite design was used to optimize the effects of steam pressure, pressure retention time, and straw moisture content on the yield of reducing sugar. All the investigated variables had significant effects (P < 0.001) on the reducing sugar yield. The optimum yield of 30.86% was obtained under the following pretreatment conditions: steam pressure, 1.54 MPa; pressure retention time, 140.5 Sec; and straw moisture content, 41.6%. The yield after thermal treatment under the same conditions was approximately 16%. Infrared (IR) radiation analysis showed a decrease in the cellulose IR crystallization index. ST noticeably increases reducing sugars in rice straw, and this technique may also be applicable to other cellulose/lignin sources of biomass. © 2014 International Union of Biochemistry and Molecular Biology, Inc.

Laccase enzyme detoxifies hydrolysates and improves biogas production from hemp straw and miscanthus.

PubMed

Schroyen, Michel; Van Hulle, Stijn W H; Holemans, Sander; Vervaeren, Han; Raes, Katleen

2017-11-01

The impact of various phenolic compounds, vanillic acid, ferulic acid, p-coumaric acid and 4-hydroxybenzoic acid on anaerobic digestion of lignocellulosic biomass (hemp straw and miscanthus) was studied. Such phenolic compounds have been known to inhibit biogas production during anaerobic digestion. The different phenolic compounds were added in various concentrations: 0, 100, 500, 1000 and 2000mg/L. A difference in inhibition of biomethane production between the phenolic compounds was noted. Hydrolysis rate, during anaerobic digestion of miscanthus was inhibited up to 50% by vanillic acid, while vanillic acid had no influence on the initial rate of biogas production during the anaerobic digestion of hemp straw. Miscanthus has a higher lignin concentration (12-30g/100gDM) making it less accessible for degradation, and in combination with phenolic compounds released after harsh pretreatments, it can cause severe inhibition levels during the anaerobic digestion, lowering biogas production. To counter the inhibition, lignin degrading enzymes can be used to remove or degrade the inhibitory phenolic compounds. The interaction of laccase and versatile peroxidase individually with the different phenolic compounds was studied to have insight in the polymerization of inhibitory compounds or breakdown of lignocellulose. Hemp straw and miscanthus were incubated with 0, 100 and 500mg/L of the different phenolic compounds for 0, 6 and 24h and pretreated with the lignin degrading enzymes. A laccase pretreatment successfully detoxified the substrate, while versatile peroxidase however was inhibited by 100mg/L of each of the individual phenolic compounds. Finally a combination of enzymatic detoxification and subsequent biogas production showed that a decrease in phenolic compounds by laccase treatment can considerably lower the inhibition levels of the biogas production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prewashing enhances the liquid hot water pretreatment efficiency of waste wheat straw with high free ash content.

PubMed

Huang, Chen; Wu, Xinxing; Huang, Yang; Lai, Chenhuan; Li, Xin; Yong, Qiang

2016-11-01

The effect of prewashing process prior to the liquid hot water (LHW) pretreatment of high free ash content waste wheat straw (WWS) was investigated. It was found that prewashing process decreased the ash content of WWS greatly, from 29.48% to 9.82%. This contributed to the lower pH value of prehydrolyzate and higher xylan removal in the following LHW pretreatment. More importantly, the prewashing process effectively increased the cellulose enzymatic hydrolysis efficiency of pretreated WWS, from 53.04% to 84.15%. The acid buffering capacity (ABC) and cation exchange capacity (CEC) of raw and prewashed WWS were examined. The majority of free ash removal from WWS by prewashing resulted in the decrease of the ABC of the WWS from 211.74 to 61.81mmol/pH-kg, and potentially enhancing the efficiency of the follow-up LHW pretreatment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biogas production from wheat straw and manure--impact of pretreatment and process operating parameters.

PubMed

Risberg, Kajsa; Sun, Li; Levén, Lotta; Horn, Svein Jarle; Schnürer, Anna

2013-12-01

Non-treated or steam-exploded straw in co-digestion with cattle manure was evaluated as a substrate for biogas production compared with manure as the sole substrate. All digestions were performed in laboratory-scale CSTR reactors (5L) operating with an organic loading late of approximately 2.8 g VS/L/day, independent of substrate mixture. The hydraulic retention was 25 days and an operating temperature of 37, 44 or 52°C. The co-digestion with steam exploded straw and manure was evaluated with two different mixtures, with different proportion. The results showed stable performance but low methane yields (0.13-0.21 N L CH4/kg VS) for both manure alone and in co-digestion with the straw. Straw appeared to give similar yield as manure and steam-explosion treatment of the straw did not increase gas yields. Furthermore, there were only slight differences at the different operating temperatures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effect of bioaugmentation by cellulolytic bacteria enriched from sheep rumen on methane production from wheat straw.

PubMed

Ozbayram, E Gozde; Kleinsteuber, Sabine; Nikolausz, Marcell; Ince, Bahar; Ince, Orhan

2017-08-01

The aim of this study was to determine the potential of bioaugmentation with cellulolytic rumen microbiota to enhance the anaerobic digestion of lignocellulosic feedstock. An anaerobic cellulolytic culture was enriched from sheep rumen fluid using wheat straw as substrate under mesophilic conditions. To investigate the effects of bioaugmentation on methane production from straw, the enrichment culture was added to batch reactors in proportions of 2% (Set-1) and 4% (Set-2) of the microbial cell number of the standard inoculum slurry. The methane production in the bioaugmented reactors was higher than in the control reactors. After 30 days of batch incubation, the average methane yield was 154 mL N CH 4 g VS -1 in the control reactors. Addition of 2% enrichment culture did not enhance methane production, whereas in Set-2 the methane yield was increased by 27%. The bacterial communities were examined by 454 amplicon sequencing of 16S rRNA genes, while terminal restriction fragment length polymorphism (T-RFLP) fingerprinting of mcrA genes was applied to analyze the methanogenic communities. The results highlighted that relative abundances of Ruminococcaceae and Lachnospiraceae increased during the enrichment. However, Cloacamonaceae, which were abundant in the standard inoculum, dominated the bacterial communities of all batch reactors. T-RFLP profiles revealed that Methanobacteriales were predominant in the rumen fluid, whereas the enrichment culture was dominated by Methanosarcinales. In the batch rectors, the most abundant methanogens were affiliated to Methanobacteriales and Methanomicrobiales. Our results suggest that bioaugmentation with sheep rumen enrichment cultures can enhance the performance of digesters treating lignocellulosic feedstock. Copyright © 2017 Elsevier Ltd. All rights reserved.

Cellulase stability, adsorption/desorption profiles and recycling during successive cycles of hydrolysis and fermentation of wheat straw.

PubMed

Rodrigues, Ana Cristina; Felby, Claus; Gama, Miguel

2014-03-01

The potential of enzymes recycling after hydrolysis and fermentation of wheat straw under a variety of conditions was investigated, monitoring the activity of the enzymes in the solid and liquid fractions, using low molecular weight substrates. A significant amount of active enzymes could be recovered by recycling the liquid phase. In the early stage of the process, enzyme adsorb to the substrate, then gradually returning to the solution as the saccharification proceeds. At 50°C, normally regarded as an acceptable operational temperature for saccharification, the enzymes (Celluclast) significantly undergo thermal deactivation. The hydrolysis yield and enzyme recycling efficiency in consecutive recycling rounds can be increased by using high enzyme loadings and moderate temperatures. Indeed, the amount of enzymes in the liquid phase increased with its thermostability and hydrolytic efficiency. This study contributes towards developing effective enzymes recycling strategies and helping to reduce the enzyme costs on bioethanol production. Copyright © 2014 Elsevier Ltd. All rights reserved.

Comparison of some new pretreatment methods for second generation bioethanol production from wheat straw and water hyacinth.

PubMed

Guragain, Yadhu Nath; De Coninck, Joelle; Husson, Florence; Durand, Alain; Rakshit, Sudip Kumar

2011-03-01

Pretreatment of lignocellulosic residues like water hyacinth (WH) and wheat straw (WS) using crude glycerol (CG) and ionic liquids (IL) pretreatment was evaluated and compared with conventional dilute acid pretreatment (DAT) in terms of enzymatic hydrolysis yield and fermentation yield of pretreated samples. In the case of WS, 1-butyl-3-methylimidazolium acetate pretreatment was found to be the best method. The hydrolysis yields of glucose and total reducing sugars were 2.1 and 3.3 times respectively higher by IL pretreatment than DAT, while it was 1.4 and 1.9 times respectively higher with CG pretreatment. For WH sample, CG pretreatment was as effective as DAT and more effective than IL pretreatment regarding hydrolysis yield. The fermentation inhibition was not noticeable with both types of pretreatment methods and feedstocks. Besides, CG pretreatment was found as effective as pure glycerol pretreatment for both feedstocks. This opens up an attractive economic route for the utilization of CG. Copyright © 2010 Elsevier Ltd. All rights reserved.

Optimization of the Alkaline Pretreatment of Rice Straw for Enhanced Methane Yield

PubMed Central

Song, Zilin; Yang, Gaihe; Han, Xinhui; Feng, Yongzhong; Ren, Guangxin

2013-01-01

The lime pretreatment process for rice straw was optimized to enhance the biodegradation performance and increase biogas yield. The optimization was implemented using response surface methodology (RSM) and Box-Behnken experimental design. The effects of biodegradation, as well as the interactive effects of Ca(OH)2 concentration, pretreatment time, and inoculum amount on biogas improvement, were investigated. Rice straw compounds, such as lignin, cellulose, and hemicellulose, were significantly degraded with increasing Ca(OH)2 concentration. The optimal conditions for the use of pretreated rice straw in anaerobic digestion were 9.81% Ca(OH)2 (w/w TS), 5.89 d treatment time, and 45.12% inoculum content, which resulted in a methane yield of 225.3 mL/g VS. A determination coefficient (R 2) of 96% was obtained, indicating that the model used to predict the anabolic digestion process shows a favorable fit with the experimental parameters. PMID:23509824

Responses of Wheat Yield, Macro- and Micro-Nutrients, and Heavy Metals in Soil and Wheat following the Application of Manure Compost on the North China Plain.

PubMed

Wang, Fan; Wang, Zhaohui; Kou, Changlin; Ma, Zhenghua; Zhao, Dong

2016-01-01

The recycling of livestock manure in cropping systems is considered to enhance soil fertility and crop productivity. However, there have been no systematic long-term studies of the effects of manure application on soil and crop macro- and micro-nutrients, heavy metals, and crop yields in China, despite their great importance for sustainable crop production and food safety. Thus, we conducted field experiments in a typical cereal crop production area of the North China Plain to investigate the effects of compost manure application rates on wheat yield, as well as on the macro-/micro-nutrients and heavy metals contents of soil and wheat. We found that compost application increased the soil total N and the available K, Fe, Zn, and Mn concentrations, whereas the available P in soil was not affected, and the available Cu decreased. In general, compost application had no significant effects on the grain yield, biomass, and harvest index of winter wheat. However, during 2012 and 2013, the N concentration decreased by 9% and 18% in straw, and by 16% and 12% in grain, respectively. With compost application, the straw P concentration only increased in 2012 but the grain P generally increased, while the straw K concentration tended to decrease and the grain K concentration increased in 2013. Compost application generally increased the Fe and Zn concentrations in straw and grain, whereas the Cu and Mn concentrations decreased significantly compared with the control. The heavy metal concentrations increased at some compost application rates, but they were still within the safe range. The balances of the macro-and micro-nutrients indicated that the removal of nutrients by wheat was compensated for by the addition of compost, whereas the level of N decreased without the application of compost. The daily intake levels of micronutrients via the consumption of wheat grain were still lower than the recommended levels when sheep manure compost was applied, except for that of Mn.

Responses of Wheat Yield, Macro- and Micro-Nutrients, and Heavy Metals in Soil and Wheat following the Application of Manure Compost on the North China Plain

PubMed Central

Wang, Fan; Wang, Zhaohui; Kou, Changlin; Ma, Zhenghua; Zhao, Dong

2016-01-01

The recycling of livestock manure in cropping systems is considered to enhance soil fertility and crop productivity. However, there have been no systematic long-term studies of the effects of manure application on soil and crop macro- and micro-nutrients, heavy metals, and crop yields in China, despite their great importance for sustainable crop production and food safety. Thus, we conducted field experiments in a typical cereal crop production area of the North China Plain to investigate the effects of compost manure application rates on wheat yield, as well as on the macro-/micro-nutrients and heavy metals contents of soil and wheat. We found that compost application increased the soil total N and the available K, Fe, Zn, and Mn concentrations, whereas the available P in soil was not affected, and the available Cu decreased. In general, compost application had no significant effects on the grain yield, biomass, and harvest index of winter wheat. However, during 2012 and 2013, the N concentration decreased by 9% and 18% in straw, and by 16% and 12% in grain, respectively. With compost application, the straw P concentration only increased in 2012 but the grain P generally increased, while the straw K concentration tended to decrease and the grain K concentration increased in 2013. Compost application generally increased the Fe and Zn concentrations in straw and grain, whereas the Cu and Mn concentrations decreased significantly compared with the control. The heavy metal concentrations increased at some compost application rates, but they were still within the safe range. The balances of the macro-and micro-nutrients indicated that the removal of nutrients by wheat was compensated for by the addition of compost, whereas the level of N decreased without the application of compost. The daily intake levels of micronutrients via the consumption of wheat grain were still lower than the recommended levels when sheep manure compost was applied, except for that of Mn. PMID

Straw use and availability for second generation biofuels in England.

PubMed

Glithero, Neryssa J; Wilson, Paul; Ramsden, Stephen J

2013-08-01

Meeting EU targets for renewable transport fuels by 2020 will necessitate a large increase in bioenergy feedstocks. Although deployment of first generation biofuels has been the major response to meeting these targets they are subject to wide debate on their sustainability leading to the development of second generation technologies which use lignocellulosic feedstocks. Second generation biofuel can be subdivided into those from dedicated bioenergy crops (DESGB), e.g. miscanthus, or those from co-products (CPSGB) such as cereal straw. Potential supply of cereal straw as a feedstock for CPSGB's is uncertain in England due to the difficulty in obtaining data and the uncertainty in current estimates. An on-farm survey of 249 farms (Cereal, General Cropping and Mixed) in England was performed and linked with Farm Business Survey data to estimate current straw use and potential straw availability. No significant correlations between harvested grain and straw yields were found for wheat and oilseed rape and only a weak correlation was observed for barley. In England there is a potential cereal straw supply of 5.27 Mt from arable farm types; 3.82 Mt are currently used and 1.45 Mt currently chopped and incorporated. If currently chopped and incorporated cereal straw from arable farm types was converted into bioethanol, this could represent 1.5% of the UK petrol consumption by energy equivalence. The variations in regional straw yields (t ha -1 ) have a great effect on the England supply of straw and the potential amount of bioethanol that can be produced.

Efficient bioconversion of rice straw to ethanol with TiO2/UV pretreatment.

PubMed

Kang, Hee-Kyoung; Kim, Doman

2012-01-01

Rice straw is a lignocellulosic biomass that constitutes a renewable organic substance and alternative source of energy; however, its structure confounds the liberation of monosaccharides. Pretreating rice straw using a TiO(2)/UV system facilitated its hydrolysis with Accellerase 1000(™), suggesting that hydroxyl radicals (OH·) from the TiO(2)/UV system could degrade lignin and carbohydrates. TiO(2)/UV pretreatment was an essential step for conversion of hemicellulose to xylose; optimal conditions for this conversion were a TiO(2) concentration of 0.1% (w/v) and an irradiation time of 2 h with a UV-C lamp at 254 nm. After enzymatic hydrolysis, the sugar yields from rice straw pretreated with these parameters were 59.8 ± 0.7% of the theoretical for glucose (339 ± 13 mg/g rice straw) and 50.3 ± 2.8% for xylose (64 ± 3 mg/g rice straw). The fermentation of enzymatic hydrolysates containing 10.5 g glucose/L and 3.2 g xylose/L with Pichia stipitis produced 3.9 g ethanol/L with a corresponding yield of 0.39 g/g rice straw. The maximum possible ethanol conversion rate is 76.47%. TiO(2)/UV pretreatment can be performed at room temperature and atmospheric pressure and demonstrates potential in large-scale production of fermentable sugars.

Uncovering the Potential of Termite Gut Microbiome for Lignocellulose Bioconversion in Anaerobic Batch Bioreactors

PubMed Central

Auer, Lucas; Lazuka, Adèle; Sillam-Dussès, David; Miambi, Edouard; O'Donohue, Michael; Hernandez-Raquet, Guillermina

2017-01-01

Termites are xylophages, being able to digest a wide variety of lignocellulosic biomass including wood with high lignin content. This ability to feed on recalcitrant plant material is the result of complex symbiotic relationships, which involve termite-specific gut microbiomes. Therefore, these represent a potential source of microorganisms for the bioconversion of lignocellulose in bioprocesses targeting the production of carboxylates. In this study, gut microbiomes of four termite species were studied for their capacity to degrade wheat straw and produce carboxylates in controlled bioreactors. All of the gut microbiomes successfully degraded lignocellulose and up to 45% w/w of wheat straw degradation was observed, with the Nasutitermes ephratae gut-microbiome displaying the highest levels of wheat straw degradation, carboxylate production and enzymatic activity. Comparing the 16S rRNA gene diversity of the initial gut inocula to the bacterial communities in lignocellulose degradation bioreactors revealed important changes in community diversity. In particular, taxa such as Spirochaetes and Fibrobacteres that were highly abundant in the initial gut inocula were replaced by Firmicutes and Proteobacteria at the end of incubation in wheat straw bioreactors. Overall, this study demonstrates that termite-gut microbiomes constitute a reservoir of lignocellulose-degrading bacteria that can be harnessed in artificial conditions for biomass conversion processes that lead to the production of useful molecules. PMID:29312279

[Adsorption behavior of copper ion and methylene blue on citric acid- esterified wheat straw].

PubMed

Sun, Jin; Zhong, Ke-Ding; Feng, Min; Liu, Xing-Yan; Gong, Ren-Min

2008-03-01

A cationic adsorbent with carboxyl groups derived from citric acid- esterified wheat straw (EWS) was prepared by the method of solid phase preparation, and a batch experiment was conducted to study the adsorption behaviors of Cu (II) and methylene blue (MB) in aqueous solution on the EWS under conditions of different initial pH, adsorbent dosage, adsorbate concentration, and contact time. The results showed that the maximum adsorption of Cu (II) and MB was obtained when the initial solution pH was > or = 4.0. 96% of Cu (II) in 100 mg x L(-1) Cu solution and 99% of MB in 250 mg x L(-1) dye solution could be removed by > or = 2.0 g x L(-1) of EWS. The adsorption of Cu (II) and MB fitted the Langmuir sorption isothermal model. The maximum removal capacity (Qm) of EWS was 79.37 mg x g(-1) for Cu (II) and 312.50 mg x g(-1) for MB, and the adsorption equilibrium of Cu (II) and MB was reached within 75 min and 5 h, respectively. The adsorption processes of Cu (II) and MB could be described by pseudo-first order and pseudo-second order kinetic functions, respectively.

Thermal Degradation, Mechanical Properties and Morphology of Wheat Straw Flour Filled Recycled Thermoplastic Composites

PubMed Central

Mengeloglu, Fatih; Karakus, Kadir

2008-01-01

Thermal behaviors of wheat straw flour (WF) filled thermoplastic composites were measured applying the thermogravimetric analysis and differential scanning calorimetry. Morphology and mechanical properties were also studied using scanning electron microscope and universal testing machine, respectively. Presence of WF in thermoplastic matrix reduced the degradation temperature of the composites. One for WF and one for thermoplastics, two main decomposition peaks were observed. Morphological study showed that addition of coupling agent improved the compatibility between WFs and thermoplastic. WFs were embedded into the thermoplastic matrix indicating improved adhesion. However, the bonding was not perfect because some debonding can also be seen on the interface of WFs and thermoplastic matrix. In the case of mechanical properties of WF filled recycled thermoplastic, HDPE and PP based composites provided similar tensile and flexural properties. The addition of coupling agents improved the properties of thermoplastic composites. MAPE coupling agents performed better in HDPE while MAPP coupling agents were superior in PP based composites. The composites produced with the combination of 50-percent mixture of recycled HDPE and PP performed similar with the use of both coupling agents. All produced composites provided flexural properties required by the ASTM standard for polyolefin-based plastic lumber decking boards. PMID:27879719

Biomethane production and physicochemical characterization of anaerobically digested teff (Eragrostis tef) straw pretreated by sodium hydroxide.

PubMed

Chufo, Akiber; Yuan, Hairong; Zou, Dexun; Pang, Yunzhi; Li, Xiujin

2015-04-01

The biogas production potential and biomethane content of teff straw through pretreatment by NaOH was investigated. Different NaOH concentrations (1%, 2%, 4% and 6%) were used for each four solid loadings (50, 65, 80 and 95 g/L). The effects of NaOH as pretreatment factor on the biodegradability of teff straw, changes in main compositions and enhancement of anaerobic digestion were analyzed. The result showed that, using 4% NaOH for pretreatment in 80 g/L solid loading produced 40.0% higher total biogas production and 48.1% higher biomethane content than the untreated sample of teff straw. Investigation of changes in chemical compositions and physical microstructure indicated that there was 4.3-22.1% total lignocellulosic compositions removal after three days pretreatment with NaOH. The results further revealed that NaOH pretreatment changed the structural compositions and lignin network, and improved biogas production from teff straw. Copyright © 2015 Elsevier Ltd. All rights reserved.

A diploid wheat TILLING resource for wheat functional genomics

PubMed Central

2012-01-01

Background Triticum monococcum L., an A genome diploid einkorn wheat, was the first domesticated crop. As a diploid, it is attractive genetic model for the study of gene structure and function of wheat-specific traits. Diploid wheat is currently not amenable to reverse genetics approaches such as insertion mutagenesis and post-transcriptional gene silencing strategies. However, TILLING offers a powerful functional genetics approach for wheat gene analysis. Results We developed a TILLING population of 1,532 M2 families using EMS as a mutagen. A total of 67 mutants were obtained for the four genes studied. Waxy gene mutation frequencies are known to be 1/17.6 - 34.4 kb DNA in polyploid wheat TILLING populations. The T. monococcum diploid wheat TILLING population had a mutation frequency of 1/90 kb for the same gene. Lignin biosynthesis pathway genes- COMT1, HCT2, and 4CL1 had mutation frequencies of 1/86 kb, 1/92 kb and 1/100 kb, respectively. The overall mutation frequency of the diploid wheat TILLING population was 1/92 kb. Conclusion The mutation frequency of a diploid wheat TILLING population was found to be higher than that reported for other diploid grasses. The rate, however, is lower than tetraploid and hexaploid wheat TILLING populations because of the higher tolerance of polyploids to mutations. Unlike polyploid wheat, most mutants in diploid wheat have a phenotype amenable to forward and reverse genetic analysis and establish diploid wheat as an attractive model to study gene function in wheat. We estimate that a TILLING population of 5, 520 will be needed to get a non-sense mutation for every wheat gene of interest with 95% probability. PMID:23134614

The impact of particle size and initial solid loading on thermochemical pretreatment of wheat straw for improving sugar recovery.

PubMed

Rojas-Rejón, Oscar A; Sánchez, Arturo

2014-07-01

This work studies the effect of initial solid load (4-32 %; w/v, DS) and particle size (0.41-50 mm) on monosaccharide yield of wheat straw subjected to dilute H(2)SO(4) (0.75 %, v/v) pretreatment and enzymatic saccharification. Response surface methodology (RSM) based on a full factorial design (FFD) was used for the statistical analysis of pretreatment and enzymatic hydrolysis. The highest xylose yield obtained during pretreatment (ca. 86 %; of theoretical) was achieved at 4 % (w/v, DS) and 25 mm. The solid fraction obtained from the first set of experiments was subjected to enzymatic hydrolysis at constant enzyme dosage (17 FPU/g); statistical analysis revealed that glucose yield was favored with solids pretreated at low initial solid loads and small particle sizes. Dynamic experiments showed that glucose yield did not increase after 48 h of enzymatic hydrolysis. Once established pretreatment conditions, experiments were carried out with several initial solid loading (4-24 %; w/v, DS) and enzyme dosages (5-50 FPU/g). Two straw sizes (0.41 and 50 mm) were used for verification purposes. The highest glucose yield (ca. 55 %; of theoretical) was achieved at 4 % (w/v, DS), 0.41 mm and 50 FPU/g. Statistical analysis of experiments showed that at low enzyme dosage, particle size had a remarkable effect over glucose yield and initial solid load was the main factor for glucose yield.

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

PubMed

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.

Effect of four pretreatments on enzymatic hydrolysis and ethanol fermentation of wheat straw. Influence of inhibitors and washing.

PubMed

Toquero, Cristina; Bolado, Silvia

2014-04-01

Pretreatment is essential in the production of alcohol from lignocellulosic material. In order to increase enzymatic sugar release and bioethanol production, thermal, dilute acid, dilute basic and alkaline peroxide pretreatments were applied to wheat straw. Compositional changes in pretreated solid fractions and sugars and possible inhibitory compounds released in liquid fractions were analysed. SEM analysis showed structural changes after pretreatments. Enzymatic hydrolysis and fermentation by Pichia stipitis of unwashed and washed samples from each pretreatment were performed so as to compare sugar and ethanol yields. The effect of the main inhibitors found in hydrolysates (formic acid, acetic acid, 5-hydroxymethylfurfural and furfural) was first studied through ethanol fermentations of model media and then compared to real hydrolysates. Hydrolysates of washed alkaline peroxide pretreated biomass provided the highest sugar concentrations, 31.82g/L glucose, and 13.75g/L xylose, their fermentation yielding promising results, with ethanol concentrations reaching 17.37g/L. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Hydraulic Retention Time on Anaerobic Digestion of Wheat Straw in the Semicontinuous Continuous Stirred-Tank Reactors

PubMed Central

Shi, Xiao-Shuang; Yu, Jun-Hong; Yin, Hua; Hu, Shu-Min; Huang, Shu-Xia

2017-01-01

Three semicontinuous continuous stirred-tank reactors (CSTR) operating at mesophilic conditions (35°C) were used to investigate the effect of hydraulic retention time (HRT) on anaerobic digestion of wheat straw. The results showed that the average biogas production with HRT of 20, 40, and 60 days was 46.8, 79.9, and 89.1 mL/g total solid as well as 55.2, 94.3, and 105.2 mL/g volatile solids, respectively. The methane content with HRT of 20 days, from 14.2% to 28.5%, was the lowest among the three reactors. The pH values with HRT of 40 and 60 days were in the acceptable range compared to that with HRT of 20 days. The propionate was dominant in the reactor with HRT of 20 days, inhibiting the activities of methanogens and causing the lower methane content in biogas. The degradation of cellulose, hemicellulose, and crystalline cellulose based on XRD was also strongly influenced by HRTs. PMID:28589134

Utilization of wheat straw for the preparation of coated controlled-release fertilizer with the function of water retention.

PubMed

Xie, Lihua; Liu, Mingzhu; Ni, Boli; Wang, Yanfang

2012-07-18

With the aim of improving fertilizer use efficiency and minimizing the negative impact on the environment, a new coated controlled-release fertilizer with the function of water retention was prepared. A novel low water solubility macromolecular fertilizer, poly(dimethylourea phosphate) (PDUP), was "designed" and formulated from N,N'-dimethylolurea (DMU) and potassium dihydrogen phosphate. Simultaneously, an eco-friendly superabsorbent composite based on wheat straw (WS), acrylic acid (AA), 2-acryloylamino-2-methyl-1-propanesulfonic acid (AMPS), and N-hydroxymethyl acrylamide (NHMAAm) was synthesized and used as the coating to control the release of nutrient. The nitrogen release profile and water retention capacity of the product were also investigated. The degradation of the coating material in soil solution was studied. Meanwhile, the impact of the content of N-hydroxymethyl acrylamide on the degradation extent was examined. The experimental data showed that the product with good water retention and controlled-release capacities, being economical and eco-friendly, could be promising for applications in agriculture and horticulture.

Genetic variability in arbuscular mycorrhizal fungi compatibility supports the selection of durum wheat genotypes for enhancing soil ecological services and cropping systems in Canada.

PubMed

Singh, A K; Hamel, C; Depauw, R M; Knox, R E

2012-03-01

Crop nutrient- and water-use efficiency could be improved by using crop varieties highly compatible with arbuscular mycorrhizal fungi (AMF). Two greenhouse experiments demonstrated the presence of genetic variability for this trait in modern durum wheat ( Triticum turgidum L. var. durum Desf.) germplasm. Among the five cultivars tested, 'AC Morse' had consistently low levels of AM root colonization and DT710 had consistently high levels of AM root colonization, whereas 'Commander', which had the highest colonization levels under low soil fertility conditions, developed poor colonization levels under medium fertility level. The presence of genetic variability in durum wheat compatibility with AMF was further evidenced by significant genotype × inoculation interaction effects in grain and straw biomass production; grain P, straw P, and straw K concentrations under medium soil fertility level; and straw K and grain Fe concentrations at low soil fertility. Mycorrhizal dependency was an undesirable trait of 'Mongibello', which showed poor growth and nutrient balance in the absence of AMF. An AMF-mediated reduction in grain Cd under low soil fertility indicated that breeding durum wheat for compatibility with AMF could help reduce grain Cd concentration in durum wheat. Durum wheat genotypes should be selected for compatibility with AMF rather than for mycorrhizal dependency.

Optimization of liquid fermentation of microbial consortium WSD-5 followed by saccharification and acidification of wheat straw.

PubMed

Wen, Boting; Yuan, Xufeng; Cao, Yanzhuan; Liu, Yan; Wang, Xiaofen; Cui, Zongjun

2012-08-01

The microbial consortium WSD-5 is composed of bacteria and fungi, and the cooperation and symbiosis of the contained microbes enhance the degradation ability of WSD-5. Experiment results showed that the highest cellulase and hemicellulase were obtained when ventilation volume was 4 L/min, stirring rate was 0 rpm, and substrate loading rate was 3%. After 6 days of cultivation, a 67.60% loss in wheat straw dry weight was observed. The crude enzyme secreted from WSD-5 after optimization was evaluated by experiments of saccharification and acidification. The maximum concentration of reducing sugars was 3254 mg/L after 48 h saccharification. The concentration of sCOD peaked on day 2 with a value of 4345 mg/L during acidification, and the biogas yield and methane yield were 22.3% and 32.3% higher than un-acidified samples. This study is the first attempt to explore both the saccharification and the acidification ability of crude enzymes secreted by microbial consortium. Copyright © 2012 Elsevier Ltd. All rights reserved.

Registration of 'Norden' hard red spring wheat

USDA-ARS?s Scientific Manuscript database

Grain yield, protein content, and straw strength are the three primary traits that growers consider when selecting wheat cultivars in the Red River Valley region of Minnesota and North Dakota. ‘Norden’ (PI 665250) was released by the University of Minnesota Agricultural Experiment Station in 2012 b...

Effect of biological pretreatments in enhancing corn straw biogas production.

PubMed

Zhong, Weizhang; Zhang, Zhongzhi; Luo, Yijing; Sun, Shanshan; Qiao, Wei; Xiao, Meng

2011-12-01

A biological pretreatment with new complex microbial agents was used to pretreat corn straw at ambient temperature (about 20°C) to improve its biodegradability and anaerobic biogas production. A complex microbial agent dose of 0.01% (w/w) and pretreatment time of 15 days were appropriate for biological pretreatment. These treatment conditions resulted in 33.07% more total biogas yield, 75.57% more methane yield, and 34.6% shorter technical digestion time compared with the untreated sample. Analyses of chemical compositions showed 5.81-25.10% reductions in total lignin, cellulose, and hemicellulose contents, and 27.19-80.71% increases in hot-water extractives; these changes contributed to the enhancement of biogas production. Biological pretreatment could be an effective method for improving biodegradability and enhancing the highly efficient biological conversion of corn straw into bioenergy. Copyright © 2011 Elsevier Ltd. All rights reserved.

Study on allelopathic effects of Rice and Wheat Soil-Like Substrate on several plants

NASA Astrophysics Data System (ADS)

Li, Leyuan; Fu, Wenting; He, Wenting; Liu, Hong

Rice and wheat are the traditional food of Chinese people, and therefore the main crop candidates for bio-regenerative life-support systems. Recycling rice and wheat straw is an important issue concerning the system. In order to decide if the mixed-substrate made of rice and wheat straw is suitable of plant cultivation, Rice and Wheat Soil-Like Substrate was tested in an aqueous extract germination experiment. The effects of different concentrations of aqueous extract on seed vigor, seedling growth and development situations and the physiological and biochemical characteristics of wheat, lettuce and pumpkin were studied, and the presence and degrees of allelopathic effects were analyzed. The test results showed that this type of SLS exerted different degrees of allelopathic effect on wheat and lettuce; this allelopathic effect was related to the concentration of SLS aqueous extract. The most significant phenomenon is that with the increase of aqueous extract concentration, the seed germination, root length and shoot fresh weight of wheat decreased; and every concentration of aqueous extract showed significant inhibition on the root length and root fresh weight of lettuce. However, this type of SLS showed little effect on the growth of pumpkin seedlings. Contents changes of chlorophyll and endogenous hormones in wheat and lettuce seedlings, and the chemical compositions of SLS were measured, and the mechanism of allelopathic effect was preliminarily analyzed.

Dynamic modeling the composting process of the mixture of poultry manure and wheat straw.

PubMed

Petric, Ivan; Mustafić, Nesib

2015-09-15

Due to lack of understanding of the complex nature of the composting process, there is a need to provide a valuable tool that can help to improve the prediction of the process performance but also its optimization. Therefore, the main objective of this study is to develop a comprehensive mathematical model of the composting process based on microbial kinetics. The model incorporates two different microbial populations that metabolize the organic matter in two different substrates. The model was validated by comparison of the model and experimental data obtained from the composting process of the mixture of poultry manure and wheat straw. Comparison of simulation results and experimental data for five dynamic state variables (organic matter conversion, oxygen concentration, carbon dioxide concentration, substrate temperature and moisture content) showed that the model has very good predictions of the process performance. According to simulation results, the optimum values for air flow rate and ambient air temperature are 0.43 l min(-1) kg(-1)OM and 28 °C, respectively. On the basis of sensitivity analysis, the maximum organic matter conversion is the most sensitive among the three objective functions. Among the twelve examined parameters, μmax,1 is the most influencing parameter and X1 is the least influencing parameter. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of magnetite powder on anaerobic co-digestion of pig manure and wheat straw.

PubMed

Wang, Yanzi; Ren, Guangxin; Zhang, Tong; Zou, Shuzhen; Mao, Chunlan; Wang, Xiaojiao

2017-08-01

This study investigated the effects of different amounts of magnetite powder (i.e., 0g, 1.5g, 3g, 4.5g, 6g) on the anaerobic co-digestion of pig manure (PM) and wheat straw (WS). The variations in pH, alkalinity, cellulase activity (CEA), dehydrogenase activity (DHA) and methane production, were analyzed by phases. Correlation of the activities of the two enzymes with methane production was also analyzed, and the Gompertz model was used to evaluate the efficiency of anaerobic digestion (AD) with the addition of magnetite powder. The results showed that magnetite powder had significant effects on the anaerobic co-digestion of PM and WS. The maximum total methane production with the addition of 3g of magnetite powder was 195mL/g total solids (TS), an increase of 72.1%. The CEA and DHA increased with magnetite powder in the ranges of 1.5-4.5g, 1.5-6g, respectively, while the methane production showed a better correlation with DHA than with CEA. Using the Gompertz model, the efficiency of AD was optimal when adding 3g magnetite powder, with higher methane production potential (206mL/g TS), shorter lag-phase time (14.9d) and shorter AD period (44d). Copyright © 2017 Elsevier Ltd. All rights reserved.

Unveiling the metabolic potential of two soil-derived microbial consortia selected on wheat straw

PubMed Central

Jiménez, Diego Javier; Chaves-Moreno, Diego; van Elsas, Jan Dirk

2015-01-01

Based on the premise that plant biomass can be efficiently degraded by mixed microbial cultures and/or enzymes, we here applied a targeted metagenomics-based approach to explore the metabolic potential of two forest soil-derived lignocellulolytic microbial consortia, denoted RWS and TWS (bred on wheat straw). Using the metagenomes of three selected batches of two experimental systems, about 1.2 Gb of sequence was generated. Comparative analyses revealed an overrepresentation of predicted carbohydrate transporters (ABC, TonB and phosphotransferases), two-component sensing systems and β-glucosidases/galactosidases in the two consortia as compared to the forest soil inoculum. Additionally, “profiling” of carbohydrate-active enzymes showed significant enrichments of several genes encoding glycosyl hydrolases of families GH2, GH43, GH92 and GH95. Sequence analyses revealed these to be most strongly affiliated to genes present on the genomes of Sphingobacterium, Bacteroides, Flavobacterium and Pedobacter spp. Assembly of the RWS and TWS metagenomes generated 16,536 and 15,902 contigs of ≥10 Kb, respectively. Thirteen contigs, containing 39 glycosyl hydrolase genes, constitute novel (hemi)cellulose utilization loci with affiliation to sequences primarily found in the Bacteroidetes. Overall, this study provides deep insight in the plant polysaccharide degrading capabilities of microbial consortia bred from forest soil, highlighting their biotechnological potential. PMID:26343383

Mineralisation of 14C-labelled synthetic lignin and ligninolytic enzyme activities of litter-decomposing basidiomycetous fungi.

PubMed

Steffen, K T; Hofrichter, M; Hatakka, A

2000-12-01

Within a screening program, 27 soil litter-decomposing basidiomycetes were tested for ligninolytic enzyme activities using agar-media containing 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonate), a humic acid or Mn2+ ions as indicator substrates. Most active species were found within the family Strophariaceae (Agrocybe praecox, Stropharia coronilla, S. rugosoannulata) and used for mineralisation experiments with a 14C-ring-labelled synthetic lignin (14C-DHP). The fungi mineralised around 25% of the lignin to 14CO2 within 12 weeks of incubation in a straw environment; about 20% of the lignin was converted to water-soluble fragments. Mn-peroxidase was found to be the predominant ligninolytic enzyme of all three fungi in liquid culture and its production was strongly enhanced in the presence of Mn2+ ions. The results of this study demonstrate that certain ubiquitous litter-decomposing basidiomycetes possess ligninolytic activities similar to the wood-decaying white-rot fungi, the most efficient lignin degraders in nature.

Modified Rice Straw as Adsorbent Material to Remove Aflatoxin B1 from Aqueous Media and as a Fiber Source in Fino Bread

PubMed Central

Mohamed, Sherif R.; El-Desouky, Tarek A.; Hussein, Ahmed M. S.; Mohamed, Sherif S.; Naguib, Khayria M.

2016-01-01

The aims of the current work are in large part the benefit of rice straw to be used as adsorbent material and natural source of fiber in Fino bread. The rice straw was subjected to high temperature for modification process and the chemical composition was carried out and the native rice straw contained about 41.15% cellulose, 20.46% hemicellulose, and 3.91% lignin while modified rice straw has 42.10, 8.65, and 5.81%, respectively. The alkali number was tested and showed an increase in the alkali consumption due to the modification process. The different concentrations of modified rice straw, aflatoxin B1, and pH were tested for removal of aflatoxin B1 from aqueous media and the maximum best removal was at 5% modified rice straw, 5 ng/mL aflatoxin B1, and pH 7. The modified rice straw was added to Fino bread at a level of 5, 10, and 15% and the chemical, rheological, baking quality, staling, and sensory properties were studied. Modified rice straw induced an increase of the shelf life and the produced Fino bread has a better consistency. PMID:26989411

Strong cellulase inhibitors from the hydrothermal pretreatment of wheat straw

PubMed Central

2013-01-01

Background The use of the enzymatic hydrolysis of lignocellulose with subsequent fermentation to ethanol provides a green alternative for the production of transportation fuels. Because of its recalcitrant nature, the lignocellulosic biomass must be pretreated before enzymatic hydrolysis. However, the pretreatment often results in the formation of compounds that are inhibitory for the enzymes or fermenting organism. Although well recognized, little quantitative information on the inhibition of individual cellulase components by identified inhibitors is available. Results Strong cellulase inhibitors were separated from the liquid fraction of the hydrothermal pretreatment of wheat straw. HPLC and mass-spectroscopy analyses confirmed that the inhibitors were oligosaccharides (inhibitory oligosaccharides, IOS) with a degree of polymerization from 7 to 16. The IOS are composed of a mixture of xylo- (XOS) and gluco-oligosaccharides (GOS). We propose that XOS and GOS are the fragments of the xylan backbone and mixed-linkage β-glucans, respectively. The IOS were approximately 100 times stronger inhibitors for Trichoderma reesei cellobiohydrolases (CBHs) than cellobiose, which is one of the strongest inhibitors of these enzymes reported to date. Inhibition of endoglucanases (EGs) by IOS was weaker than that of CBHs. Most of the tested cellulases and hemicellulases were able to slowly degrade IOS and reduce the inhibitory power of the liquid fraction to some extent. The most efficient single enzyme component here was T. reesei EG TrCel7B. Although reduced by the enzyme treatment, the residual inhibitory power of IOS and the liquid fraction was strong enough to silence the major component of the T. reesei cellulase system, CBH TrCel7A. Conclusions The cellulase inhibitors described here may be responsible for the poor yields from the enzymatic conversion of the whole slurries from lignocellulose pretreatment under conditions that do not favor complete degradation of

Effect of Straw Amendment on Soil Zn Availability and Ageing of Exogenous Water-Soluble Zn Applied to Calcareous Soil.

PubMed

Chen, Yanlong; Cui, Juan; Tian, Xiaohong; Zhao, Aiqing; Li, Meng; Wang, Shaoxia; Li, Xiushaung; Jia, Zhou; Liu, Ke

2017-01-01

Organic matter plays a key role in availability and transformation of soil Zn (zinc), which greatly controls Zn concentrations in cereal grains and human Zn nutrition level. Accordingly, soils homogenized with the wheat straw (0, 12 g straw kg-1) and Zn fertilizer (0, 7 mg Zn kg-1) were buried and incubated in the field over 210 days to explore the response of soil Zn availability and the ageing of exogenous Zn to straw addition. Results indicated that adding straw alone scarcely affected soil DTPA-Zn concentration and Zn fractions because of the low Zn concentration of wheat straw and the high soil pH, and large clay and calcium carbonate contents. However, adding exogenous Zn plus straw increased the DTPA-Zn abundance by about 5-fold and had the similar results to adding exogenous Zn alone, corresponding to the increased Zn fraction loosely bounded to organic matter, which had a more dominant presence in Zn reaction than soil other constituents such as carbonate and minerals in calcareous soil. The higher relative amount of ineffective Zn (~50%) after water soluble Zn addition also occurred, and at the days of 120-165 and 180-210when the natural temperature and rainfall changed mildly, the ageing process of exogenous Zn over time was well evaluated by the diffusion equation, respectively. Consequently, combining crop residues with exogenous water soluble Zn application is promising strategy to maximize the availability of Zn in calcareous soil, but the higher ageing rate of Zn caused by the higher Zn mobility should be considered.

Unravelling lignin formation and structure. Final report, April 1, 1988--March 31, 1991

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, N.G.

1991-12-31

During this study, we established that the Fagaceae exclusively accumulate Z-monolignois/glucosides, and not the E-isomers. Evidence for the presence of a novel E{yields}Z isomerse has been obtained. Our pioneering work in lignin biosynthesis and structure in situ has also progressed smoothly. We established the bonding environments of a woody angiosperm, Leucanea leucocephala, as well as wheat (T. aestivum) and tobacco (N. tabacum). A cell culture system from Pinus taeda was developed which seems ideal for investigating the early stages of lignification. These cultures excrete peroxidase isozymes, considered to be specifically involved in lignin deposition. We also studied the effect ofmore » the putative lignin-degrading enzyme, lignin peroxidase, on monolignols and dehydropolymerisates therefrom. In all cases, polymerization was observed, and not degradation; these polymers are identical to that obtained with horseradish peroxidases/H{sub 2}O{sub 2}. It seems inconceivable that these enzymes can be considered as being primarily responsible for lignin biodegradation.« less

Process optimization for the preparation of straw feedstuff for rearing yellow mealworms (Tenebrio molitor L.) in BLSS

NASA Astrophysics Data System (ADS)

Li, Leyuan; Liu, lh64. Hong

2012-07-01

It has been confirmed in our previous work that in bioregenerative life support systems, feeding yellow mealworms (Tenebrio molitor L.) using fermented straw has the potential to provide good animal protein for astronauts, meanwhile treating with plant wastes. However, since the nitrogen content in straw is very low, T. molitor larvae can not obtain sufficient nitrogen, which results in a relatively low growth efficiency. In this study, wheat straw powder was mixed with simulated human urine before fermentation. Condition parameters, e.g. urine:straw ratio, moisture content, inoculation dose, fermentation time, fermentation temperature and pH were optimized using Taguchi method. Larval growth rate and average individual mass of mature larva increased significantly in the group of T. molitor larvae fed with feedstuff prepared with the optimized process.

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

PubMed

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% (P<0.05), and the degradation rates of cellulose, 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.

[Effects of Different Residue Part Inputs of Corn Straws on CO2 Efflux and Microbial Biomass in Clay Loam and Sandy Loam Black Soils].

PubMed

Liu, Si-yi; Liang, Ai-zhen; Yang, Xue-ming; Zhang, Xiao-ping; Jia, Shu-xia; Chen, Xue-wen; Zhang, Shi-xiu; Sun, Bing-jie; Chen, Sheng-long

2015-07-01

The decomposed rate of crop residues is a major determinant for carbon balance and nutrient cycling in agroecosystem. In this study, a constant temperature incubation study was conducted to evaluate CO2 emission and microbial biomass based on four different parts of corn straw (roots, lower stem, upper stem and leaves) and two soils with different textures (sandy loam and clay loam) from the black soil region. The relationships between soil CO2 emission, microbial biomass and the ratio of carbon (C) to nitrogen (N) and lignin of corn residues were analyzed by the linear regression. Results showed that the production of CO2 was increased with the addition of different parts of corn straw to soil, with the value of priming effect (PE) ranged from 215. 53 µmol . g-1 to 335. 17 µmol . g -1. Except for corn leaves, the cumulative CO2 production and PE of clay loam soil were significantly higher than those in sandy loam soil. The correlation of PE with lignin/N was obviously more significant than that with lignin concentration, nitrogen concentration and C/N of corn residue. The addition of corn straw to soil increased the contents of MBC and MBN and decreased MBC/MBN, which suggested that more nitrogen rather than carbon was conserved in microbial community. The augmenter of microbial biomass in sandy loam soil was greater than that in clay loam soil, but the total dissolved nitrogen was lower. Our results indicated that the differences in CO2 emission with the addition of residues to soils were primarily ascribe to the different lignin/N ratio in different corn parts; and the corn residues added into the sandy loam soil could enhance carbon sequestration, microbial biomass and nitrogen holding ability relative to clay loam soil.

Fermentation Quality and Additives: A Case of Rice Straw Silage

PubMed Central

Oladosu, Yusuff; Magaji, Usman; Hussin, Ghazali; Ramli, Asfaliza; Miah, Gous

2016-01-01

Rice cultivation generates large amount of crop residues of which only 20% are utilized for industrial and domestic purposes. In most developing countries especially southeast Asia, rice straw is used as part of feeding ingredients for the ruminants. However, due to its low protein content and high level of lignin and silica, there is limitation to its digestibility and nutritional value. To utilize this crop residue judiciously, there is a need for improvement of its nutritive value to promote its utilization through ensiling. Understanding the fundamental principle of ensiling is a prerequisite for successful silage product. Prominent factors influencing quality of silage product include water soluble carbohydrates, natural microbial population, and harvesting conditions of the forage. Additives are used to control the fermentation processes to enhance nutrient recovery and improve silage stability. This review emphasizes some practical aspects of silage processing and the use of additives for improvement of fermentation quality of rice straw. PMID:27429981

Fermentation Quality and Additives: A Case of Rice Straw Silage.

PubMed

Oladosu, Yusuff; Rafii, Mohd Y; Abdullah, Norhani; Magaji, Usman; Hussin, Ghazali; Ramli, Asfaliza; Miah, Gous

2016-01-01

Rice cultivation generates large amount of crop residues of which only 20% are utilized for industrial and domestic purposes. In most developing countries especially southeast Asia, rice straw is used as part of feeding ingredients for the ruminants. However, due to its low protein content and high level of lignin and silica, there is limitation to its digestibility and nutritional value. To utilize this crop residue judiciously, there is a need for improvement of its nutritive value to promote its utilization through ensiling. Understanding the fundamental principle of ensiling is a prerequisite for successful silage product. Prominent factors influencing quality of silage product include water soluble carbohydrates, natural microbial population, and harvesting conditions of the forage. Additives are used to control the fermentation processes to enhance nutrient recovery and improve silage stability. This review emphasizes some practical aspects of silage processing and the use of additives for improvement of fermentation quality of rice straw.

Effect of urea and urea-gamma treatments on cellulose degradation of Thai rice straw and corn stalk

NASA Astrophysics Data System (ADS)

Banchorndhevakul, Siriwattana

2002-08-01

Cellulose degradation of 20% urea treated and 20% urea-10 kGy gamma treated Thai rice straw and corn stalk showed that combination effect of urea and gamma radiation gave a higher % decrease in neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), cellulose, hemicellulose, and lignin and cutin in comparison with urea effect only for both room temperature storage and room temperature +258 K storage. The results also indicated that cellulose degradation proceeded with time, even at 258 K. A drastic drop to less than half of the original contents in NDF, ADF, and ADL could not be obtained in this study.

Effect of hydrogen peroxide pretreatment on the structural features and the enzymatic hydrolysis of rice straw.

PubMed

Wei, C J; Cheng, C Y

1985-10-01

Assessment was made to evaluate the effect of hydrogen peroxide pretreatment on the change of the structural features and the enzymatic hydrolysis of rice straw. Changes in the lignin content, weight loss, accessibility for Cadoxen, water holding capacity, and crystallinity of straw were measured during pretreatment to express the modification of the lignocellulosic structure of straw. The rates and the extents of enzymatic hydrolysis, cellulase adsorption, and cellobiose accumulation in the initial stage of hydrolysis were determined to study the pretreatment effect on hydrolysis. Pretreatment at 60 degrees C for 5 h in a solution with 1% (w/w) H(2)O(2) and NaOH resulted in 60% delignification, 40% weight loss, a fivefold increase in the accessibility for Cadoxen, an one times increase in the water-holding capacity, and only a slight decrease in crystallinity as compared with that of the untreated straw. Improvement on the pretreatment effect could be made by increasing the initial alkalinity and the pretreatment temperature of hydrogen peroxide solution. A saturated improvement on the structural features was found when the weight ratio of hydrogen peroxide to straw was above 0.25 g H(2)O(2)/g straw in an alkaline H(2)O(2) solution with 1% (w/w) NaOH at 32 degrees C. The initial rates and extents of hydrolysis, cellulase adsorption, and cellobiose accumulation in hydrolysis were enhanced in accordance with the improved structural features of straw pretreated. A four times increase in the extent of the enzymatic hydrolysis of straw for 24 h was attributed to the alkaline hydrogen peroxide pretreatment.

Effects of Saccharomyces cerevisiae Supplementation and Anhydrous Ammonia Treatment of Wheat Straw on In-situ Degradability and, Rumen Fermentation and Growth Performance of Yearling Lambs

PubMed Central

Cömert, Muazzez; Şayan, Yılmaz; Özelçam, Hülya; Baykal, Gülşah Yeğenoğlu

2015-01-01

The effects of Saccharomyces cerevisiae supplementation (6.6×108 cfu) and anhydrous ammonia treatment (3%) of wheat straw (WS) were investigated on in-situ dry matter (DM) degradability, and on rumen fermentation and growth performance of lambs. Rumen-fistulated Menemen sheep fed a diet with and without live yeast were used to assess the DM degradability characteristics of WS and ammonia-treated wheat straw (WSNH3). Twenty-six yearling Menemen male lambs were fed in four groups. Lambs of control group (WS) received untreated WS without supplemental yeast, whereas other three groups were fed WS treated with anhydrous ammonia (WSNH3 group), untreated WS and yeast (WS+YEAST group) or WS treated with anhydrous ammonia and yeast (WSNH3+YEAST group). Supplemented live yeast (4 g/d) was added in the diet. Lambs were offered untreated or ammonia treated WS ad-libitum and concentrate was fed at 1% of live body weight. The degradability of the water-insoluble (fraction B) was significantly increased by all of the treatment groups. Potential degradability (A+B), effective DM degradability’s (pe2, pe5, and pe8) and average daily weight gain increased only in WSNH3+YEAST group (p<0.05). Voluntary DM intake was not increased by the treatments (p>0.05), but voluntary metabolizable energy and crude protein intake were increased by WSNH3 and by WSNH3+YEAST (p<0.05). Average daily rumen pH was not affected by any of the treatments, but average daily NH3-N was significantly higher in the WSNH3 and WSNH3+YEAST groups, and total volatile fatty acids were significantly higher in the WS+YEAST and WSNH3+YEAST groups. In conclusion, the improvement of feed value of WS was better by the combination of ammonia-treatment and yeast supplementation compared to either treatment alone. PMID:25656177

Influence on anaerobic digestion by intermediate thermal hydrolysis of waste activated sludge and co-digested wheat straw.

PubMed

Bjerg-Nielsen, Michael; Ward, Alastair James; Møller, Henrik Bjarne; Ottosen, Lars Ditlev Mørck

2018-02-01

This paper analyses time (30 and 60 min) and temperature (120-190 °C) effects of intermediate thermal hydrolysis (ITHP) in a two-step anaerobic digestion of waste activated sludge (WAS) with and without wheat straw as a co-substrate. Effects were analyzed by measuring biochemical methane potential for 60 days and assessing associated kinetic and chemical data. Compared to non-treatment, ITHP increased the secondary step methane yield from 52 to 222 L CH 4  kg VS -1 and from 147 to 224 L CH 4  kg VS -1 for pre-digested WAS and pre-co-digested WAS respectively at an optimum of 170 °C and 30 min. The hydrolysis coefficients (k hyd ) increased by up to 127% following treatment. Increasing ITHP time from 30 to 60 min showed ambiguous results regarding methane yields, whilst temperature had a clear and proportional effect on the concentrations of acetic acid. The energy balances were found to be poor and dewatering to increase total solids above the values tested here is necessary for this process to be energetically feasible. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sugarcane biomass for biorefineries: comparative composition of carbohydrate and non-carbohydrate components of bagasse and straw.

PubMed

Szczerbowski, Danielle; Pitarelo, Ana Paula; Zandoná Filho, Arion; Ramos, Luiz Pereira

2014-12-19

Two fractions of sugarcane, namely bagasse and straw (or trash), were characterized in relation to their chemical composition. Bagasse presented values of glucans, hemicelluloses, lignin and ash of 37.74, 27.23, 20.57 and 6.53%, respectively, while straw had 33.77, 27.38, 21.28 and 6.23% of these same components. Ash content was relatively high in both cane biomass fractions. Bagasse showed higher levels of contaminating oxides while straw had a higher content of alkaline and alkaline-earth oxides. A comparison between the polysaccharide chemical compositions of these lignocellulosic materials suggests that similar amounts of fermentable sugars are expected to arise from their optimal pretreatment and enzymatic hydrolysis. Details about the chemical properties of cane biomass holocellulose, hemicelluloses A and B and α-cellulose are provided, and these may offer a good opportunity for designing more efficient enzyme cocktails for substrate saccharification. Copyright © 2014 Elsevier Ltd. All rights reserved.

Flammulina velutipes treatment of non-sterile tall wheat grass for enhancing biodegradability and methane production.

PubMed

Kasprzycka, Agnieszka; Lalak-Kańczugowska, Justyna; Tys, Jerzy

2018-05-09

In this study fungal pretreatment of non-sterile tall wheat grass via the white rot fungi Flammulina velutipes was studied and the effect on biodegradability of lignocellulosic biomass and methane production, was evaluated. Degradation of lignin, cellulose, hemicellulose, and dry matter in non-sterile tall wheat grass during 28 days of fungal pretreatment using different inoculum ratio (0%-50%) and moisture content (MC) (45% MC, 65% MC, and 75% MC) were assessed via comparison to untreated biomass. Pretreatment with F. velutipes was most effective at 65% MC and 40% inoculum ratio, resulting in 22% lignin removal. The corresponding methane yields were 181.3 Ndm 3 ·kg VS -1 , which were 280% higher than for the untreated tall wheat grass. Copyright © 2018 Elsevier Ltd. All rights reserved.

Butyric acid fermentation from pretreated and hydrolysed wheat straw by an adapted Clostridium tyrobutyricum strain

PubMed Central

Baroi, G N; Baumann, I; Westermann, P; Gavala, H N

2015-01-01

Butyric acid is a valuable building-block for the production of chemicals and materials and nowadays it is produced exclusively from petroleum. The aim of this study was to develop a suitable and robust strain of Clostridium tyrobutyricum that produces butyric acid at a high yield and selectivity from lignocellulosic biomasses. Pretreated (by wet explosion) and enzymatically hydrolysed wheat straw (PHWS), rich in C6 and C5 sugars (71.6 and 55.4 g l−1 of glucose and xylose respectively), was used as substrate. After one year of serial selections, an adapted strain of C. tyrobutyricum was developed. The adapted strain was able to grow in 80% (v v−1) PHWS without addition of yeast extract compared with an initial tolerance to less than 10% PHWS and was able to ferment both glucose and xylose. It is noticeable that the adapted C. tyrobutyricum strain was characterized by a high yield and selectivity to butyric acid. Specifically, the butyric acid yield at 60–80% PHWS lie between 0.37 and 0.46 g g−1 of sugar, while the selectivity for butyric acid was as high as 0.9–1.0 g g−1 of acid. Moreover, the strain exhibited a robust response in regards to growth and product profile at pH 6 and 7. PMID:26230610

Kinetic study of corn straw pyrolysis: comparison of two different three-pseudocomponent models.

PubMed

Li, Zhengqi; Zhao, Wei; Meng, Baihong; Liu, Chunlong; Zhu, Qunyi; Zhao, Guangbo

2008-11-01

With heating rates of 20, 50 and 100 K min(-1), the thermal decomposition of corn straw samples (corn stalks skins, corn stalks cores, corn bracts and corn leaves) were studied using thermogravimetric analysis. The maximum pyrolysis rates increased with the heating rate increasing and the temperature at the peak pyrolysis rate also increased. Assuming the addition of three independent parallel reactions, corresponding to three pseudocomponents linked to the hemicellulose, cellulose and lignin, two different three-pseudocomponent models were used to simulate the corn straw pyrolysis. Model parameters of pyrolysis were given. It was found that the three-pseudocomponent model with n-order kinetics was more accurate than the model with first-order kinetics at most cases. It showed that the model with n-order kinetics was more accurate to describe the pyrolysis of the hemicellulose.

PCDD/F EMISSIONS FROM BURNING WHEAT AND RICE FIELD RESIDUE

EPA Science Inventory

The paper presents the first known values for emissions of polychlorinated dibenzodioxins and dibenzofurans (PCDDs/Fs) from combustion of agricultural field biomass. Wheat and rice straw stubble collected from two western U.S. states were tested in a field burn simulation to dete...

Mapping quantitative trait loci with additive effects and additive x additive epistatic interactions for biomass yield, grain yield, and straw yield using a doubled haploid population of wheat (Triticum aestivum L.).

PubMed

Li, Z K; Jiang, X L; Peng, T; Shi, C L; Han, S X; Tian, B; Zhu, Z L; Tian, J C

2014-02-28

Biomass yield is one of the most important traits for wheat (Triticum aestivum L.)-breeding programs. Increasing the yield of the aerial parts of wheat varieties will be an integral component of future wheat improvement; however, little is known regarding the genetic control of aerial part yield. A doubled haploid population, comprising 168 lines derived from a cross between two winter wheat cultivars, 'Huapei 3' (HP3) and 'Yumai 57' (YM57), was investigated. Quantitative trait loci (QTL) for total biomass yield, grain yield, and straw yield were determined for additive effects and additive x additive epistatic interactions using the QTLNetwork 2.0 software based on the mixed-linear model. Thirteen QTL were determined to have significant additive effects for the three yield traits, of which six also exhibited epistatic effects. Eleven significant additive x additive interactions were detected, of which seven occurred between QTL showing epistatic effects only, two occurred between QTL showing epistatic effects and additive effects, and two occurred between QTL with additive effects. These QTL explained 1.20 to 10.87% of the total phenotypic variation. The QTL with an allele originating from YM57 on chromosome 4B and another QTL contributed by HP3 alleles on chromosome 4D were simultaneously detected on the same or adjacent chromosome intervals for the three traits in two environments. Most of the repeatedly detected QTL across environments were not significant (P > 0.05). These results have implications for selection strategies in wheat biomass yield and for increasing the yield of the aerial part of wheat.

[Soil respiration and carbon balance in wheat field under conservation tillage].

PubMed

Zhang, Sai; Wang, Long-Chang; Huang, Zhao-Cun; Jia, Hui-Juan; Ran, Chun-Yan

2014-06-01

In order to study the characteristics of carbon sources and sinks in the winter wheat farmland ecosystem in southwest hilly region of China, the LI6400-09 respiratory chamber was adopted in the experiment conducted in the experimental field in Southwest University in Chongqing. The soil respiration and plant growth dynamics were analyzed during the growth period of wheat in the triple intercropping system of wheat-maize-soybean. Four treatments including T (traditional tillage), R (ridge tillage), TS (traditional tillage + straw mulching), and RS (ridge tillage + straw mulching) were designed. Root biomass regression (RR) and root exclusion (RE) were used to compare the contribution of root respiration to total soil respiration. The results showed that the average soil respiration rate was 1.71 micromol x (m2 x s)(-1) with a variation of 0.62-2.91 micromol x (m2 x s)(-1). Significant differences in soil respiration rate were detected among different treatments. The average soil respiration rate of T, R, TS and RS were 1.29, 1.59, 1.99 and 1.96 micromol x (m2 x s)(-1), respectively. R treatment did not increase the soil respiration rate significantly until the jointing stage. Straw mulching treatment significantly increased soil respiration, with a steadily high rate during the whole growth period. During the 169 days of growth, the total soil respiration was 2 266.82, 2799.52, 3 483.73 and 3 443.89 kg x hm(-2) while the cumulative aboveground biomasses were 51 800.84, 59 563.20, 66 015.37 and 7 1331.63 kg x hm(-2). Compared with the control, the yield of R, TS and RS increased by 14.99%, 27.44% and 37.70%, respectively. The contribution of root respiration to total soil respiration was 47.05% by RBR, while it was 53.97% by RE. In the early growth period, the carbon source was weak. The capacity of carbon sink started to increase at the jointing stage and reached the maximum during the filling stage. The carbon budget of wheat field was 5 924.512, 6743.807, 8350

Biosorption of heavy metal ions using wheat based biosorbents--a review of the recent literature.

PubMed

Farooq, Umar; Kozinski, Janusz A; Khan, Misbahul Ain; Athar, Makshoof

2010-07-01

Conventional technologies for the removal/remediation of toxic metal ions from wastewaters are proving expensive due to non-regenerable materials used and high costs. Biosorption is emerging as a technique offering the use of economical alternate biological materials for the purpose. Functional groups like carboxyl, hydroxyl, sulphydryl and amido present in these biomaterials, make it possible for them to attach metal ions from waters. Every year, large amounts of straw and bran from Triticum aestivum (wheat), a major food crop of the world, are produced as by-products/waste materials. The purpose of this article is to review rather scattered information on the utilization of straw and bran for the removal/minimization of metal ions from waters. High efficiency, high biosorption capacity, cost-effectiveness and renewability are the important parameters making these materials as economical alternatives for metal removal and waste remediation. Applications of available adsorption and kinetic models as well as influences of change in temperature and pH of medium on metal biosorption by wheat straw and wheat bran are reviewed. The biosorption mechanism has been found to be quite complex. It comprises a number of phenomena including adsorption, surface precipitation, ion-exchange and complexation. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

LCA of 1,4-Butanediol Produced via Direct Fermentation of Sugars from Wheat Straw Feedstock within a Territorial Biorefinery

PubMed Central

Forte, Annachiara; Zucaro, Amalia; Basosi, Riccardo; Fierro, Angelo

2016-01-01

The bio-based industrial sector has been recognized by the European Union as a priority area toward sustainability, however, the environmental profile of bio-based products needs to be further addressed. This study investigated, through the Life Cycle Assessment (LCA) approach, the environmental performance of bio-based 1,4-butanediol (BDO) produced via direct fermentation of sugars from wheat straw, within a hypothetical regional biorefinery (Campania Region, Southern Italy). The aim was: (i) to identify the hotspots along the production chain; and (ii) to assess the potential environmental benefits of this bio-based polymer versus the reference conventional product (fossil-based BDO). Results identified the prevailing contribution to the total environmental load of bio-based BDO in the feedstock production and in the heat requirement at the biorefinery plant. The modeled industrial bio-based BDO supply chain, showed a general reduction of the environmental impacts compared to the fossil-based BDO. The lowest benefits were gained in terms of acidification and eutrophication, due to the environmental load of the crop phase for feedstock cultivation. PMID:28773687

Rice straw pretreatment using deep eutectic solvents with different constituents molar ratios: Biomass fractionation, polysaccharides enzymatic digestion and solvent reuse.

PubMed

Li, Ao-Lin; Hou, Xue-Dan; Lin, Kai-Peng; Zhang, Xuan; Fu, Ming-Hui

2018-04-12

Lignocellulosic biomass pretreatment with deep eutectic solvents (DESs) is a promising and challenging process for production of biofuels and valuable platform chemicals. In this work, rice straw was mainly fractionated into carbohydrate-rich materials (CRMs) and lignin-rich materials (LRMs) by 90% lactic acid/choline chloride (LC)-water solution with different molar ratio of hydrogen bond donor (HBD, lactic acid) and hydrogen bond acceptor (HBA, choline chloride). It was found that high HBD/HBA molar ratio of DESs was favorable for achieving CRMs and LRMs with high purity, and both HBD and HBA were responsible for effective biomass fractionation possibly due to their synergistic effect on highly efficient breakage of the linkage between hemicellulose and lignin and thus lignin extraction. About 30%-35% of lignin in native rice straw was fractionated as LRMs, and exceeding 70% of xylan were removed and fractionated into the liquid stream as forms of xylose, furfural and humins after pretreatment using aqueous LC (3:1, 5:1) solution. Consequently, polysaccharides enzymatic hydrolysis of the CRMs were significantly enhanced. Moreover, all the DESs could be recovered with high yields of around 90%, and 69% of the LC (3:1) was recovered after 5 cycles reuse at 90 °C. Besides, the recycled DES maintained a good pretreatment ability, and glucose yields of 60-70% were achieved in the enzymatic hydrolysis of CRMs obtained in each cycle. The facile process established in present work is promising for large scale production of fermentable sugars and other chemicals. Copyright © 2018 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Water–use efficiency of dryland wheat in response to mulching and tillage practices on the Loess Plateau

PubMed Central

Wang, Li-fang; Shangguan, Zhou-ping

2015-01-01

Mulching and tillage are widely considered to be major practices for improving soil and water conservation where water is scarce. This paper studied the effects of FM (flat mulching), RFM (ridge-furrow mulching), SM (straw mulching), MTMC (mulching with two materials combined), MOM (mulching with other materials), NT (no-tillage) ST (subsoiling tillage) and RT (rotational tillage) on wheat yield based on a synthesis of 85 recent publications (including 2795 observations at 24 sites) in the Loess Plateau, China. This synthesis suggests that wheat yield was in the range of 259–7898 kg ha−1 for FM and RFM. The sequence of water use efficiency (WUE) effect sizes was similar to that of wheat yield for the practices. Wheat yields were more sensitive to soil water at planting covered by plastic film, wheat straw, liquid film, water-permeable plastic film and sand compared to NT, ST and RT. RFM and RT increased the yields of wheat by 18 and 15%, respectively, and corresponding for WUE by 20.11 and 12.50%. This synthesis demonstrates that RFM was better for avoiding the risk of reduced production due to lack of precipitation; however, under conditions of better soil moisture, RT and MTMC were also economic. PMID:26192158

Transfer factor of (90)Sr and (137)Cs to lettuce and winter wheat at different growth stage applications.

PubMed

Al Attar, Lina; Al-Oudat, Mohammad; Safia, Bassam; Ghani, Basem Abdul

2015-12-01

The effect of clay soil contamination time on the transfer factors (Fvs) of (137)Cs and (90)Sr was investigated in four different growth stages of winter wheat and lettuce crops. The experiment was performed in an open field using lysimeters. The Fvs were the ratio of the activity concentrations of the radionuclides in crops to those in soil, both as dry weight (Bq kg(-1)). Significant difference of log-Fvs was evaluated using one-way Analysis of Variance (ANOVA). Basically, Fvs of (90)Sr were higher than those of (137)Cs, despite of the application stage or crop' variety. Higher Fvs for both radionuclides were observed for lettuce in comparison to winter wheat. Fvs of (90)Sr showed comparable trends for both crops with enhanced Fvs obtained when contamination occurred in early stages, i.e. 1.20 for lettuce and 0.88 and 0.02 for winter wheat, straw and grains, respectively. Despite the fluctuation noted in the pattern of Fvs for (137)Cs, soil contaminated at the second stage gave the highest Fvs for lettuce and grains, with geometric means of 0.21 and 0.01, respectively. However, wheat-straw showed remarkable increase in Fv for the latest contamination (ripening stage), about 0.06. It could be concluded that soil contamination at early growth stages would represent high radiological risk for the scenarios studied with an exception to (137)Cs in winter wheat-straw which reflected greater hazard at the latest application. Copyright © 2015 Elsevier Ltd. All rights reserved.

Butyric acid fermentation from pretreated and hydrolysed wheat straw by an adapted Clostridium tyrobutyricum strain.

PubMed

Baroi, G N; Baumann, I; Westermann, P; Gavala, H N

2015-09-01

Butyric acid is a valuable building-block for the production of chemicals and materials and nowadays it is produced exclusively from petroleum. The aim of this study was to develop a suitable and robust strain of Clostridium tyrobutyricum that produces butyric acid at a high yield and selectivity from lignocellulosic biomasses. Pretreated (by wet explosion) and enzymatically hydrolysed wheat straw (PHWS), rich in C6 and C5 sugars (71.6 and 55.4 g l(-1) of glucose and xylose respectively), was used as substrate. After one year of serial selections, an adapted strain of C. tyrobutyricum was developed. The adapted strain was able to grow in 80% (v v(-1) ) PHWS without addition of yeast extract compared with an initial tolerance to less than 10% PHWS and was able to ferment both glucose and xylose. It is noticeable that the adapted C. tyrobutyricum strain was characterized by a high yield and selectivity to butyric acid. Specifically, the butyric acid yield at 60-80% PHWS lie between 0.37 and 0.46 g g(-1) of sugar, while the selectivity for butyric acid was as high as 0.9-1.0 g g(-1) of acid. Moreover, the strain exhibited a robust response in regards to growth and product profile at pH 6 and 7. © 2015 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

Effects of purified lignin on in vitro rumen metabolism and growth performance of feedlot cattle

PubMed Central

Wang, Yuxi; McAllister, Tim A.; Lora, Jairo H.

2017-01-01

Objective The objectives were to assess the effects of purified lignin from wheat straw (sodium hydroxide dehydrated lignin; SHDL) on in vitro ruminal fermentation and on the growth performance of feedlot cattle. Methods In vitro experiments were conducted by incubating a timothy-alfalfa (50:50) forage mixture (48 h) and barley grain (24 h) with 0, 0.25, 0.5, 1.0, and 2.0 mg/mL of rumen fluid (equivalent to 0, 2, 4, 8, and 16 g SHDL/kg diet). Productions of CH4 and total gas, volatile fatty acids, ammonia, dry matter (DM) disappearance (DMD) and digestion of neutral detergent fiber (NDF) or starch were measured. Sixty Hereford-Angus cross weaned steer calves were individually fed a typical barley silage-barley grain based total mixed ration and supplemented with SHDL at 0, 4, 8, and 16 g/kg DM for 70 (growing), 28 (transition), and 121 d (finishing) period. Cattle were slaughtered at the end of the experiment and carcass traits were assessed. Results With forage, SHDL linearly (p<0.001) reduced 48-h in vitro DMD from 54.9% to 39.2%, NDF disappearance from 34.1% to 18.6% and the acetate: propionate ratio from 2.56 to 2.41, but linearly (p<0.001) increased CH4 production from 9.5 to 12.4 mL/100 mg DMD. With barley grain, SHDL linearly increased (p<0.001) 24-h DMD from74.6% to 84.5%, but linearly (p<0.001) reduced CH4 production from 5.6 to 4.2 mL/100 mg DMD and NH3 accumulation from 9.15 to 4.49 μmol/mL. Supplementation of SHDL did not affect growth, but tended (p = 0.10) to linearly reduce feed intake, and quadratically increased (p = 0.059) feed efficiency during the finishing period. Addition of SHDL also tended (p = 0.098) to linearly increase the saleable meat yield of the carcass from 52.5% to 55.7%. Conclusion Purified lignin used as feed additive has potential to improve feed efficiency for finishing feedlot cattle and carcass quality. PMID:27456424

Characteristics and mechanisms of nickel adsorption on biochars produced from wheat straw pellets and rice husk.

PubMed

Shen, Zhengtao; Zhang, Yunhui; McMillan, Oliver; Jin, Fei; Al-Tabbaa, Abir

2017-05-01

The adsorption characteristics and mechanisms of Ni 2+ on four-standard biochars produced from wheat straw pellets (WSP550, WSP700) and rice husk (RH550, RH700) at 550 and 700 °C, respectively, were investigated. The kinetic results show that the adsorption of Ni 2+ on the biochars reached an equilibrium within 5 min. The increase of the solid to liquid ratio resulted in an increase of Ni 2+ removal percentage but a decrease of the adsorbed amount of Ni 2+ per weight unit of biochar. The Ni 2+ removal percentage increased with the increasing of initial solution pH values at the range of 2-4, was relatively constant at the pH range of 4-8, and significantly increased to ≥98% at pH 9 and stayed constantly at the pH range of 9-10. The calculated maximum adsorption capacities of Ni 2+ for the biochars follow the order of WSP700 > WSP550 > RH700 > RH550. Both cation exchange capacity and pH of biochar can be a good indicator of the maximum adsorption capacity for Ni 2+ showing a positively linear and exponential relationship, respectively. This study also suggests that a carefully controlled standardised production procedure can make it reliable to compare the adsorption capacities between different biochars and investigate the mechanisms involved.

Simultaneous bioconversion of barley straw to butanol and product recovery: use of concentrated sugar solution and process integration

USDA-ARS?s Scientific Manuscript database

As a result of increased gasoline prices, we focused on the production of butanol which contains more energy than ethanol on per gallon (or kg) basis from cellulosic agricultural biomass such as wheat straw using two different systems: i) separate hydrolysis, fermentation, and recovery (SHFR), and ...

[Effects of tillage practices on root spatial distribution and yield of spring wheat and pea in the dry land farming areas of central Gansu, China].

PubMed

Zhang, Ming Jun; Li, Ling Ling; Xie, Jun Hong; Peng, Zheng Kai; Ren, Jin Hu

2017-12-01

A field experiment was conducted to explore the mechanism of cultivation measures in affecting crop yield by investigating root distribution in spring wheat-pea rotation based on a long-term conservation tillage practices in a farming region of Gansu. The results showed that with the develo-pment of growth period, the total root length, root surface area of spring wheat and pea showed a consistent trend of increase after initial decrease and reached the maximum at flowering stage. Higher root distribution was found in the 0-10 cm soil layer at seedling and 10-30 cm soil layer at flowering and maturity stages in spring wheat, while in the field pea, higher root distribution was found in the 0-10 cm soil layer at seedling and maturity, and in the 10-30 cm soil layer at flowering stages. No tillage with straw mulching and plastic mulching increased the root length and root surface area. Compared with conventional tillage in spring wheat and field pea, root length increased by 35.9% to 92.6%, and root surface area increased by 43.2% to 162.4%, respectively. No tillage with straw mulching and plastic mulching optimized spring wheat and pea root system distribution, compared with conventional tillage, increased spring wheat and field pea root length and root surface area ratio at 0-10 cm depths at the seedling stage, the root distribution at deeper depths increased significantly at flowering and maturity stages, and no tillage with straw mulching increased root length and root surface area ratio by 3.3% and 9.7% respectively, in 30-80 cm soil layer at the flowering stage. The total root length, root surface area and yield had significantly positive correlation for spring wheat in each growth period, and the total root length and pea yield also had significant positive correlation. No tillage with straw mulching and plastic mulching boosted yield of spring wheat and pea by 23.4%-38.7% compared with the conventional tillage, and the water use efficiency was increased by 13

Role of anaerobic fungi in wheat straw degradation and effects of plant feed additives on rumen fermentation parameters in vitro.

PubMed

Dagar, S S; Singh, N; Goel, N; Kumar, S; Puniya, A K

2015-01-01

In the present study, rumen microbial groups, i.e. total rumen microbes (TRM), total anaerobic fungi (TAF), avicel enriched bacteria (AEB) and neutral detergent fibre enriched bacteria (NEB) were evaluated for wheat straw (WS) degradability and different fermentation parameters in vitro. Highest WS degradation was shown for TRM, followed by TAF, NEB and least by AEB. Similar patterns were observed with total gas production and short chain fatty acid profiles. Overall, TAF emerged as the most potent individual microbial group. In order to enhance the fibrolytic and rumen fermentation potential of TAF, we evaluated 18 plant feed additives in vitro. Among these, six plant additives namely Albizia lebbeck, Alstonia scholaris, Bacopa monnieri, Lawsonia inermis, Psidium guajava and Terminalia arjuna considerably improved WS degradation by TAF. Further evaluation showed A. lebbeck as best feed additive. The study revealed that TAF plays a significant role in WS degradation and their fibrolytic activities can be improved by inclusion of A. lebbeck in fermentation medium. Further studies are warranted to elucidate its active constituents, effect on fungal population and in vivo potential in animal system.

The effects of different types of crop straw on the transformation of pentachlorophenol in flooded paddy soil.

PubMed

Lin, Jiajiang; Meng, Jun; He, Yan; Xu, Jianming; Chen, Zuliang; Brookes, Philip C

2018-02-01

The incorporation of various types of crop straw to agricultural soils has long been practiced to improve soil fertility. However, the effects of crop straw on the fate of organo-chlorine pesticides in flooded paddy soils are not well understood. The dechlorination of pentachlorophenol (PCP) in four vertical profiles (0-10, 10-20, 20-30, 30-50 mm depth) of two flooded paddy soils, a Plinthudult (Soil 1) and a Tropudult (Soil 2) was investigated following the application of four crop straws (rice, wheat, rape and Chinese milk vetch) to them. In all treatments, PCP dechlorination decreased with increasing soil depth. In the crop straw treatments, PCP was almost completely dechlorinated within 60 days, and rapidly transformed to 2,3,4,5-tetrachlorophenol, and further to 3,4,5-trichlorophenol. Further dechlorination of 3,4,5-trichlorophenol also occurred in all treatments except for the rape straw. It is possible that the NH 4 + and NO 3 - derived from the straw are responsible for the inhibition of the 3,4,5-trichlorophenol dechlorination. The reduction of Fe (III) and SO 4 2- increased following application of the crop straws. The RDA analysis indicated that the Fe (III) reducing bacteria might be involved in the ortho-dechlorination, while SO 4 2- reducing bacteria were involved in para- and meta-dechlorination of PCP. The complete detoxification of PCP depended upon both the crop straw type and soil properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sustaining fermentation in high-gravity ethanol production by feeding yeast to a temperature-profiled multifeed simultaneous saccharification and co-fermentation of wheat straw.

PubMed

Westman, Johan O; Wang, Ruifei; Novy, Vera; Franzén, Carl Johan

2017-01-01

Considerable progress is being made in ethanol production from lignocellulosic feedstocks by fermentation, but negative effects of inhibitors on fermenting microorganisms are still challenging. Feeding preadapted cells has shown positive effects by sustaining fermentation in high-gravity simultaneous saccharification and co-fermentation (SSCF). Loss of cell viability has been reported in several SSCF studies on different substrates and seems to be the main reason for the declining ethanol production toward the end of the process. Here, we investigate how the combination of yeast preadaptation and feeding, cell flocculation, and temperature reduction improves the cell viability in SSCF of steam pretreated wheat straw. More than 50% cell viability was lost during the first 24 h of high-gravity SSCF. No beneficial effects of adding selected nutrients were observed in shake flask SSCF. Ethanol concentrations greater than 50 g L -1 led to significant loss of viability and prevented further fermentation in SSCF. The benefits of feeding preadapted yeast cells were marginal at later stages of SSCF. Yeast flocculation did not improve the viability but simplified cell harvest and improved the feasibility of the cell feeding strategy in demo scale. Cultivation at 30 °C instead of 35 °C increased cell survival significantly on solid media containing ethanol and inhibitors. Similarly, in multifeed SSCF, cells maintained the viability and fermentation capacity when the temperature was reduced from 35 to 30 °C during the process, but hydrolysis yields were compromised. By combining the yeast feeding and temperature change, an ethanol concentration of 65 g L -1 , equivalent to 70% of the theoretical yield, was obtained in multifeed SSCF on pretreated wheat straw. In demo scale, the process with flocculating yeast and temperature profile resulted in 5% (w/w) ethanol, equivalent to 53% of the theoretical yield. Multifeed SSCF was further developed by means of a

Some ways of plants wastes utilization in bioregenerative life support systems

NASA Astrophysics Data System (ADS)

Kovaleva, N. P.; Tikhomirov, A. A.; Tirranen, L. S.; Ushakova, S. A.; Zolotukhin, I. G.; Anischenko, O. V.

In works on experimental modeling of bioregenerative life support systems BLSS carried out at Institute of Biophysics Russian Academy of Science Siberian Branch SB RAS the possibility of increase of a system closure degree under the condition of inedible plant biomass return into the organic matter turnover was demonstrated At the same time when radish inedible biomass was subjected to biological oxidation in soil-like substrate SLS after its drying then wheat straw was subjected to stepwise processing including mushrooms growing stage Mushrooms cultivation facilitated to lignin destruction and quicker straw decomposition On the other hand mushrooms growing required additional technological procedures leading to complication of a technological chain of straw processing The purpose of this work is to study the possibility of exclusion of mushrooms growing stage under straw pretreatment for its further use as an equivalent of radish edible biomass grown on SLS To solve the problem put by the radish cenosis in a conveyer regime was grown The conveyer included radish four ages with the conveyer step equal to 7 days The experiment consisted of two successive stages On the first stage radish was grown without straw addition into SLS control To return mineral elements into SLS the biomass grown was restored in SLS On the second stage inedible radish biomass and wheat straw were returned into SLS in the quantity equivalent to edible biomass The possibility of the method described was estimated according to plant productivity microbiological

Soil aggregate and organic carbon distribution at dry land soil and paddy soil: the role of different straws returning.

PubMed

Huang, Rong; Lan, Muling; Liu, Jiang; Gao, Ming

2017-12-01

Agriculture wastes returning to soil is one of common ways to reuse crop straws in China. The returned straws are expected to improve the fertility and structural stability of soil during the degradation of straw it selves. The in situ effect of different straw (wheat, rice, maize, rape, and broad bean) applications for soil aggregate stability and soil organic carbon (SOC) distribution were studied at both dry land soil and paddy soil in this study. Wet sieving procedures were used to separate soil aggregate sizes. Aggregate stability indicators including mean weight diameter, geometric mean diameter, mean weight of specific surface area, and the fractal dimension were used to evaluate soil aggregate stability after the incubation of straws returning. Meanwhile, the variation and distribution of SOC in different-sized aggregates were further studied. Results showed that the application of straws, especially rape straw at dry land soil and rice straw at paddy soil, increased the fractions of macro-aggregate (> 0.25 mm) and micro-aggregate (0.25-0.053 mm). Suggesting the nutrients released from straw degradation promotes the growing of soil aggregates directly and indirectly. The application of different straws increased the SOC content at both soils and the SOC mainly distributed at < 0.53 mm aggregates. However, the contribution of SOC in macro- and micro-aggregates increased. Straw-applied paddy soil have a higher total SOC content but lower SOC contents at > 0.25 and 0.25-0.053 mm aggregates with dry land soil. Rape straw in dry land and rice straw in paddy field could stabilize soil aggregates and increasing SOC contents best.

Effects of an acid/alkaline treatment on the release of antioxidants and cellulose from different agro-food wastes.

PubMed

Vadivel, Vellingiri; Moncalvo, Alessandro; Dordoni, Roberta; Spigno, Giorgia

2017-06-01

The present investigation was aimed to evaluate the release of both antioxidants and cellulosic fibre from different agro-food wastes. Cost-effective and easily available agro-food residues (brewers' spent grains, hazelnut shells, orange peels and wheat straw) were selected and submitted to a double-step acid/alkaline fractionation process. The obtained acid and alkaline liquors were analysed for total phenols content and antioxidant capacity. The final fibre residue was analysed for the cellulose, lignin and hemicellulose content. The total phenols content and antioxidant capacity of the acid liquors were higher than the alkaline hydrolysates. Orange peels and wheat straw gave, respectively, the highest (19.70±0.68mg/g dm ) and the lowest (4.70±0.29mg/g dm ) total phenols release. Correlation between antioxidant capacity of the liquors and their origin depended on the analytical assay used to evaluate it. All the acid liquors were also rich in sugar degradation products (mainly furfural). HPLC analysis revealed that the most abundant phenolic compound in the acid liquors was vanillin for brewers' spent grains, hazelnut shells and wheat straw, and p-hydroxybenzoic acid for orange peels. Wheat straw served as the best raw material for cellulose isolation, providing a final residue with a high cellulose content (84%) which corresponded to 45% of the original cellulose. The applied process removed more than 90% of the hemicellulose fraction in all the samples, while delignification degree ranged from 67% (in hazelnut shells), to 93% (in brewers' spent grains). It was not possible to select a unique raw material for the release of highest levels of both total phenols and cellulose. Copyright © 2017 Elsevier Ltd. All rights reserved.

Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis

PubMed Central

Qin, Wei; Hu, Chunsheng; Oenema, Oene

2015-01-01

Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge. PMID:26586114

Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis.

PubMed

Qin, Wei; Hu, Chunsheng; Oenema, Oene

2015-11-20

Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge.

Soil mulching significantly enhances yields and water and nitrogen use efficiencies of maize and wheat: a meta-analysis

NASA Astrophysics Data System (ADS)

Qin, Wei; Hu, Chunsheng; Oenema, Oene

2015-11-01

Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge.

Enhanced biomass delignification and enzymatic saccharification of canola straw by steam-explosion pretreatment.

PubMed

Garmakhany, Amir Daraei; Kashaninejad, Mahdi; Aalami, Mehran; Maghsoudlou, Yahya; Khomieri, Mortza; Tabil, Lope G

2014-06-01

In recent decades, bioconversion of lignocellulosic biomass to biofuel (ethanol and biodiesel) has been extensively investigated. The three main chemical constituents of biomass are cellulose, hemicellulose and lignin. Cellulose and hemicellulose are polysaccharides of primarily fermentable sugars, glucose and xylose respectively. Hemicellulose also includes small fermentable fractions of arabinose, galactose and mannose. The main issue in converting lignocellulosic biomass to fuel ethanol is the accessibility of the polysaccharides for enzymatic breakdown into monosaccharides. This study focused on the use of steam explosion as the pretreatment method for canola straw as lignocellulosic biomass. Result showed that steam explosion treatment of biomass increased cellulose accessibility and it hydrolysis by enzyme hydrolysis. Following 72 h of enzyme hydrolysis, a maximum cellulose conversion to glucose yield of 29.40% was obtained for the steam-exploded sample while the control showed 11.60% glucose yields. Steam explosion pretreatment increased glucose production and glucose yield by 200% and 153.22%, respectively, compared to the control sample. The crystalline index increased from 57.48% in untreated canola straw to 64.72% in steam-exploded samples. Steam explosion pretreatment of biomass increased cellulose accessibility, and enzymatic hydrolysis increased glucose production and glucose yield of canola straw. © 2013 Society of Chemical Industry.

Environmental performances of coproducts. Application of Claiming-Based Allocation models to straw and vetiver biorefineries in an Indian context.

PubMed

Gnansounou, Edgard; Raman, Jegannathan Kenthorai

2018-04-24

Among the renewables, non-food and wastelands based biofuels are essential for the transport sector to achieve country's climate mitigation targets. With the growing interest in biorefineries, setting policy requirements for other coproducts along with biofuels is necessary to improve the products portfolio of biorefinery, increase the bioproducts perception by the consumers and push the technology forward. Towards this context, Claiming-Based allocation models were used in comparative life cycle assessment of multiple products from wheat straw biorefinery and vetiver biorefinery. Vetiver biorefinery shows promising Greenhouse gas emission savings (181-213%) compared to the common crop based lignocellulose (wheat straw) biorefinery. Assistance of Claiming-Based Allocation models favors to find out the affordable allocation limit (0-80%) among the coproducts in order to achieve the individual prospective policy targets. Such models show promising application in multiproduct life cycle assessment studies where appropriate allocation is challenging to achieve the individual products emission subject to policy targets. Copyright © 2018 Elsevier Ltd. All rights reserved.

Thermo-chemical pretreatment of rice straw for further processing for levulinic acid production.

PubMed

Elumalai, Sasikumar; Agarwal, Bhumica; Sangwan, Rajender S

2016-10-01

A variety of pretreatment protocols for rice straw fiber reconstruction were evaluated under mild conditions (upto 0.2%wt. and 121°C) with the object of improving polymer susceptibility to chemical attack while preserving carbohydrate sugars for levulinic acid (LA) production. Each of the protocols tested significantly enhanced pretreatment recoveries of carbohydrate sugars and lignin, and a NaOH protocol showed the most promise, with enhanced carbohydrate preservation (upto 20% relative to the other protocols) and more effective lignin dissolution (upto 60%). Consequently, post-pretreatment fibers were evaluated for LA preparation using an existing co-solvent system consisting of HCl and THF, in addition supplementation of DMSO was attempted, in order to improve final product recovery. In contrast to pretreatment response, H2SO4 protocol fibers yielded highest LA conc. (21%wt. with 36% carbohydrate conversion efficiency) under the modest reaction conditions. Apparent spectroscopic analysis witnessed for fiber destruction and delocalization of inherent constituents during pretreatment protocols. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enzyme activities and substrate degradation during white rot fungi growth on sugar-cane straw in a solid state fermentation.

PubMed

Ortega, G M; Martinez, E O; González, P C; Betancourt, D; Otero, M A

1993-03-01

Two strains of Pleurotus spp., grown in solid state fermentation on sugar-cane straw, degraded the dry matter by 50% after 60 days. The rate of substrate consumption and the dry weight of fruiting bodies decreased in consecutive flushings. Both strains vigorously attacked hemicellulose (80% of total degradation) and lignin (70%). Fruiting bodies were rich in protein and lipids, and had a low content of carbohydrates and ash.

Monitoring the impact of straw burning on particulate pollution using satellite and in-situ observations in the North China Plain

NASA Astrophysics Data System (ADS)

Zeng, C.

2015-12-01

The North China Plain is one of the main grain producing areas of China, but is also a severe straw burning zone. Winter wheat and summer corn harvests in this area usually occur from the beginning of Jun and Oct, respectively. After harvest, farmers usually burn out the remaining straw for convenience. However, straw burning can release a large quantity of air pollutants and can consequently result in a significant deterioration in regional air quality. To monitor the impact of straw burning on particulate pollution, daily MODIS thermal anomaly products (MOD14 and MYD14) were used to identify dates and regions of straw burning. Then the corresponding MODIS AOD products (MOD04 and MYD04) and particulate matter (PM) concentration observations from ground stations were integrated using a geostatistical method. By combining the accurate station-based PM observations and satellite data of well spatial coverage, PM concentration distribution maps were generated. Meanwhile, NCEP reanalysis data were used to obtain the corresponding surface wind pattern maps. Preliminary results show that satellite and station-based observations can indicate the impact of straw burning on PM pollution during harvest time. Air qualities during these times are obviously affected by the straw burning and surface wind field. Moreover, the air quality of the southeast study region is susceptible to the straw burning in adjacent areas due to the characteristic of the terrain.

Effects of different swine manure to wheat straw ratios on antibiotic resistance genes and the microbial community structure during anaerobic digestion.

PubMed

Song, Wen; Wang, Xiaojuan; Gu, Jie; Zhang, Sheqi; Yin, Yanan; Li, Yang; Qian, Xun; Sun, Wei

2017-05-01

This study explored the effects of different mass ratios of swine manure relative to wheat straw (3:7, 5:5, and 7:3, i.e., control reactors C1, C2, and C3, respectively) on variations in antibiotic resistance genes (ARGs) and the microbial community during anaerobic digestion (AD). The cumulative biogas production volumes were 1711, 3857, and 3226mL in C1, C2, and C3, respectively. After AD, the total relative abundance of ARGs decreased by 4.23 logs in C3, whereas the reductions were only 1.03 and 1.37 logs in C1 and C2, respectively. Network analysis showed that the genera Solibacillus, Enterococcus, Facklamia, Corynebacterium_1, and Acinetobacter were potential hosts of ermB, sul1, and dfrA7. Redundancy analysis showed that the bacterial communities and environmental factors played important roles in the variation in ARGs. Thus, reductions in ARGs should be considered before reusing animal manure treated by AD. Copyright © 2017 Elsevier Ltd. All rights reserved.

Impact of a smelter closedown on metal contents of wheat cultivated in the neighbourhood.

PubMed

Douay, Francis; Roussel, Hélène; Pruvot, Christelle; Waterlot, Christophe

2008-03-01

The contamination of soils by heavy metals engenders important environmental and sanitary problems in Northern France where a smelter has been located for more than one hundred of years. It has been one of the most important Pb production sites in Europe until its closedown in March 2003. Ore smelting process generated considerable atmospheric emissions of dust. Despite an active environmental strategy, these emissions were still significant in 2002 with up to 17 tonnes of Pb, 32 tonnes of Zn and 1 tonne of Cd. Over the years, the generated deposits have led to an important contamination of the surrounding soils. Previous studies have shown pollutant transfers to plants, which can induce a risk for human and animal health. The objective of this study was to evaluate the consequences of the smelter closedown on the Cd and Pb contents of wheat (grain and straw) cultivated in the area. Paired topsoil and vegetable samples were taken at harvest time at various distances to the smelter. The sample sites were chosen in order to represent a large range of soil metal contamination. Sampling was realised on several wheat harvests between 1997 and 2003. 25 samples were collected before the smelter closedown and 15 after. All ears of about 1 m long of two rows were manually picked and threshed in the lab. Similarly, straw was harvested at the same time. Total metal contents in soil and wheat samples were quantified. A negative correlation between metal concentrations in soil and the distance to the smelter was shown. The wheat grain and straw showed significant Cd and Pb contents. The straw had higher metal contents than the grain. During the smelter activity, the grain contents were up to 0.8 mg kg(-1) DM of Cd and 8 mg kg(-1) DM of Pb. For the straw, maximum contents were 5 mg kg(-1) DM of Cd and 114 mg kg(-1) DM of Pb. After the smelter closedown, we observed a very large decrease of Pb in the grain (82%) and in the straw (91%). A smaller decrease was observed for Cd in

Straw enhanced CO2 and CH4 but decreased N2O emissions from flooded paddy soils: Changes in microbial community compositions

NASA Astrophysics Data System (ADS)

Wang, Ning; Yu, Jian-Guang; Zhao, Ya-Hui; Chang, Zhi-Zhou; Shi, Xiao-Xia; Ma, Lena Q.; Li, Hong-Bo

2018-02-01

To explore microbial mechanisms of straw-induced changes in CO2, CH4, and N2O emissions from paddy field, wheat straw was amended to two paddy soils from Taizhou (TZ) and Yixing (YX), China for 60 d under flooded condition. Illumia sequencing was used to characterize shift in bacterial community compositions. Compared to control, 1-5% straw amendment significantly elevated CO2 and CH4 emissions with higher increase at higher application rates, mainly due to increased soil DOC concentrations. In contrast, straw amendment decreased N2O emission. Considering CO2, CH4, and N2O emissions as a whole, an overall increase in global warming potential was observed with straw amendment. Total CO2 and CH4 emissions from straw-amended soils were significantly higher for YX than TZ soil, suggesting that straw-induced greenhouse gas emissions depended on soil characteristics. The abundance of C-turnover bacteria Firmicutes increased from 28-41% to 54-77% with straw amendment, thereby increasing CO2 and CH4 emissions. However, straw amendment reduced the abundance of denitrifying bacteria Proteobacteria from 18% to 7.2-13% or increased the abundance of N2O reducing bacteria Clostridium from 7.6-11% to 13-30%, thereby decreasing N2O emission. The results suggested straw amendment strongly influenced greenhouse gas emissions via alerting soil properties and bacterial community compositions. Future field application is needed to ascertain the effects of straw return on greenhouse gas emissions.

Investigation of cell wall composition related to stem lodging resistance in wheat (Triticum aestivum L.) by FTIR spectroscopy.

PubMed

Wang, Jian; Zhu, Jinmao; Huang, RuZhu; Yang, YuSheng

2012-07-01

We explored the rapid qualitative analysis of wheat cultivars with good lodging resistances by Fourier transform infrared resonance (FTIR) spectroscopy and multivariate statistical analysis. FTIR imaging showing that wheat stem cell walls were mainly composed of cellulose, pectin, protein, and lignin. Principal components analysis (PCA) was used to eliminate multicollinearity among multiple peak absorptions. PCA revealed the developmental internodes of wheat stems could be distributed from low to high along the load of the second principal component, which was consistent with the corresponding bands of cellulose in the FTIR spectra of the cell walls. Furthermore, four distinct stem populations could also be identified by spectral features related to their corresponding mechanical properties via PCA and cluster analysis. Histochemical staining of four types of wheat stems with various abilities to resist lodging revealed that cellulose contributed more than lignin to the ability to resist lodging. These results strongly suggested that the main cell wall component responsible for these differences was cellulose. Therefore, the combination of multivariate analysis and FTIR could rapidly screen wheat cultivars with good lodging resistance. Furthermore, the application of these methods to a much wider range of cultivars of unknown mechanical properties promises to be of interest.

Involvement of Fenton chemistry in rice straw degradation by the lignocellulolytic bacterium Pantoea ananatis Sd-1.

PubMed

Ma, Jiangshan; Zhang, Keke; Huang, Mei; Hector, Stanton B; Liu, Bin; Tong, Chunyi; Liu, Qian; Zeng, Jiarui; Gao, Yan; Xu, Ting; Liu, Ying; Liu, Xuanming; Zhu, Yonghua

2016-01-01

Lignocellulolytic bacteria have revealed to be a promising source for biofuel production, yet the underlying mechanisms are still worth exploring. Our previous study inferred that the highly efficient lignocellulose degradation by bacterium Pantoea ananatis Sd-1 might involve Fenton chemistry (Fe 2+  + H 2 O 2  + H +  → Fe 3+  + OH· + H 2 O), similar to that of white-rot and brown-rot fungi. The aim of this work is to investigate the existence of this Fenton-based oxidation mechanism in the rice straw degradation process of P. ananatis Sd-1. After 3 days incubation of unpretreated rice straw with P. ananatis Sd-1, the percentage in weight reduction of rice straw as well as its cellulose, hemicellulose, and lignin components reached 46.7, 43.1, 42.9, and 37.9 %, respectively. The addition of different hydroxyl radical scavengers resulted in a significant decline ( P  < 0.001) in rice straw degradation. Pyrolysis gas chromatography-mass spectrometry and Fourier transform infrared spectroscopy analysis revealed the consistency of chemical changes of rice straw components that exists between P. ananatis Sd-1 and Fenton reagent treatment. In addition to the increased total iron ion concentration throughout the rice straw decomposition process, the Fe 3+ -reducing capacity of P. ananatis Sd-1 was induced by rice straw and predominantly contributed by aromatic compounds metabolites. The transcript levels of the glucose-methanol-choline oxidoreductase gene related to hydrogen peroxide production were significantly up-regulated (at least P  < 0.01) in rice straw cultures. Higher activities of GMC oxidoreductase and less hydrogen peroxide concentration in rice straw cultures relative to glucose cultures may be responsible for increasing rice straw degradation, which includes Fenton-like reactions. Our results confirmed the Fenton chemistry-assisted degradation model in P. ananatis Sd-1. We are among the first to show that a Fenton-based oxidation mechanism

Prospects of rice straw as a raw material for paper making.

PubMed

Kaur, Daljeet; Bhardwaj, Nishi Kant; Lohchab, Rajesh Kumar

2017-02-01

Pulp and paper mills are indispensable for any nation as far as the growth of the nation is concerned. Due to fast growth in population, urbanization and industrialization, the demand and consumption of paper has increased tremendously. These put high load on our natural resources and force the industry to look for alternative raw material. Rice straw is a lignocellulosic material abundantly available in wood short countries like China, India, Bangladesh, etc. and can be used as raw material for this industry. Open burning of rice straw releases noxious green house gases to the air and poses serious threats to global air chemistry and human health. So, it is a dual benefit option (for farmers and industries) to use rice straw as a raw material in pulp and paper industry. Organosolv pulping using acids are the prominent choices of researchers to convert this residue into valuable pulp but in developed countries only. Developing world favours the soda and soda-AQ processes as these are economical. As a virtue of less lignin content in comparison to wood, rice straw requires less harsh conditions for cooking and can be easily pulped. Bleaching is a crucial step of paper making but also responsible for causing water pollution. Many studies revealed that during the process more than 500 chlorinated compounds are released that are highly toxic, bioaccumulative and carcinogenic in nature. Most of the industries over the globe switch on to the elemental chlorine free short sequence bleaching methods using chlorine dioxide, hypochlorite and hydrogen peroxide. This paper presented the effective need of ecofriendly, economically reliable pulping and bleaching sequences in case of rice straw to eliminate the problems of chlorinated compounds in wastewater of paper mills. Such approach of using waste as a raw material with its environmentally safe processing for making paper can prove to be valuable towards sustainable growth. Copyright © 2016 Elsevier Ltd. All rights reserved.

Residual effects of monoammonium phosphate, gypsum and elemental sulfur on cadmium phytoavailability and translocation from soil to wheat in an effluent irrigated field.

PubMed

Qayyum, Muhammad Farooq; Rehman, Muhammad Zia Ur; Ali, Shafaqat; Rizwan, Muhammad; Naeem, Asif; Maqsood, Muhammad Aamer; Khalid, Hinnan; Rinklebe, Jörg; Ok, Yong Sik

2017-05-01

Cadmium (Cd) accumulation in agricultural soils is one of the major threats to food security. The application of inorganic amendments such as mono-ammonium phosphate (MAP), gypsum and elemental sulfur (S) could alleviate the negative effects of Cd in crops. However, their long-term residual effects on decreasing Cd uptake in latter crops remain unclear. A field that had previously been applied with treatments including control and 0.2, 0.4 and 0.8% by weight of each MAP, gypsum and S, and grown with wheat and rice and thereafter wheat in the rotation was selected for this study. Wheat (Triticum aestivum L.) was grown in the same field as the third crop without further application of amendments to evaluate the residual effects of the amendments on Cd uptake by wheat. Plants were harvested at maturity and grain, and straw yield along with Cd concentration in soil, straw, and grains was determined. The addition of MAP and gypsum significantly increased wheat growth and yield and decreased Cd accumulation in straw and grains compared to control while the reverse was found in S application. Both MAP and gypsum decreased AB-DTPA extractable Cd in soil while S increased the bioavailable Cd in soil. Both MAP and gypsum increased the Cd immobilization in the soil and S decreased Cd immobilization in a dose-additive manner. We conclude that MAP and gypsum had a significant residual effect on decreasing Cd uptake in wheat. The cost-benefit ratio revealed that gypsum is an effective amendment for decreasing Cd concentration in plants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Growth, metabolism of Phanerochaete chrysosporium and route of lignin degradation in response to cadmium stress in solid-state fermentation.

PubMed

Zhao, Meihua; Zhang, Chaosheng; Zeng, Guangming; Huang, Danlian; Xu, Piao; Cheng, Min

2015-11-01

This study examines the growth, metabolism of Phanerochaete chrysosporium (P. chrysosporium) and route of lignin degradation in response to cadmium (Cd) stress in solid-state fermentation of rice straw. Less living fungi biomass was found under Cd exposure, suggesting that Cd had strong toxicity to P. chrysosporium. The maximum values of lignin peroxidase and manganese peroxidase were 0.34 and 5.21 U g(-1) at the Cd concentration of 32 mg kg(-1), respectively, lower than that in control, which indicated Cd stress would inhibit ligninolytic enzymes. The production of reactive oxygen species (ROS) including hydroxyl radicals (OH), superoxide anion radical (O2(-)) and hydrogen peroxide (H2O2) increased after Cd exposure. Higher concentration of oxalate was detected at high Cd concentrations. Cd stress also had influence on the rates of lignocelluloses degradation and the route of lignin degradation. Partial Cd could be removed by P. chrysosporium. Copyright © 2015 Elsevier Ltd. All rights reserved.

Nitrate leaching in a winter wheat-summer maize rotation on a calcareous soil as affected by nitrogen and straw management.

PubMed

Huang, Tao; Ju, Xiaotang; Yang, Hao

2017-02-08

Nitrate leaching is one of the most important pathways of nitrogen (N) loss which leads to groundwater contamination or surface water eutrophication. Clarifying the rates, controlling factors and characteristics of nitrate leaching is the pre-requisite for proposing effective mitigation strategies. We investigated the effects of interactions among chemical N fertilizer, straw and manure applications on nitrogen leaching in an intensively managed calcareous Fluvo-aquic soil with winter wheat-summer maize cropping rotations on the North China Plain from October 2010 to September 2013 using ceramic suction cups and seepage water calculations based on a long-term field experiment. Annual nitrate leaching reached 38-60 kg N ha -1 from conventional N managements, but declined by 32-71% due to optimum N, compost manure or municipal waste treatments, respectively. Nitrate leaching concentrated in the summer maize season, and fewer leaching events with high amounts are the characteristics of nitrate leaching in this region. Overuse of chemical N fertilizers, high net mineralization and nitrification, together with predominance of rainfall in the summer season with light soil texture are the main controlling factors responsible for the high nitrate leaching loss in this soil-crop-climatic system.