Search

Microcrystalline cellulose (MCC) was successfully synthesized from sugarcane bagasse using a rapid, low-temperature hydrochloric acid (HCl) gas treatment. The primary aim was to develop an energy-efficient "green" cellulose extraction process. Response surface methodology optimized the liquid-phase hydrolysis conditions to 3.3 % HCl at 117 °C for 127 min to obtain MCC with 350 degree of polymerization. An alternative gas-phase approach utilizing gaseous HCl diluted in hot 40 °C air was proposed to accelerate MCC production. The cellulose pulp was moistened to 15-18 % moisture content and then exposed to HCl gas, which was absorbed by the moisture in the cellulose fibers to generate a highly concentrated acidic solution that hydrolyzed the cellulose. The cellulose pulp was isolated from depithed bagasse through soda pulping, multistage bleaching and cold alkali purification. Hydrolysis was conducted by saturating the moist cellulose fibers with gaseous HCl mixed with hot air. Extensive analytical characterization using FT-IR, XRD, SEM, TGA, DSC, particle size, and porosity analyses verified comparable physicochemical attributes between MCC samples prepared via liquid and gas phase methods. The gas-produced MCC revealed 85% crystallinity, 71 Å crystallite dimensions, and thermally stable rod-shaped morphology with an average diameter below 200 μm. The similar material properties validate the proposed gas-based technique as an equally effective yet more energy-efficient alternative to conventional aqueous acid hydrolysis for fabricating highly pure MCC powders from lignocellulose. This sustainable approach enables the value-addition of sugarcane bagasse agro-industrial residue into cellulosic nanomaterials for wide-ranging industrial applications. In summary, the key achievements of this work are rapid MCC production under mild temperatures using HCl gas, optimization of liquid phase hydrolysis, successful demonstration of gas phase method, and extensive characterization verifying equivalence between both protocols. The gas methodology offers a greener cellulose extraction process from biomass., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

A poly(urethane-acrylate) polymer (PUA) was synthesized, and a sufficiently high molecular weight starting from urethane-acrylate oligomer (UAO) was obtained. PUA was then loaded with two types of powdered ligno-cellulosic waste, namely from licorice root and palm leaf, in amounts of 1, 5 and 10%, and the obtained composites were chemically and mechanically characterized. FTIR analysis of final PUA synthesized used for the composite production confirmed the new bonds formed during the polymerization process. The degradation temperatures of the two types of waste used were in line with what observed in most common natural fibers with an onset at 270 °C for licorice waste, and at 290 °C for palm leaf one. The former was more abundant in cellulose (44% vs. 12% lignin), whilst the latter was richer in lignin (30% vs. 26% cellulose). In the composites, only a limited reduction of degradation temperature was observed for palm leaf waste addition and some dispersion issues are observed for licorice root, leading to fluctuating results. Tensile performance of the composites indicates some reduction with respect to the pure polymer in terms of tensile strength, though stabilizing between data with 5 and 10% filler. In contrast, Shore A hardness of both composites slightly increases with higher filler content, while in stiffness-driven applications licorice-based composites showed potential due to an increase up to 50% compared to neat PUA. In general terms, the fracture surfaces tend to become rougher with filler introduction, which indicates the need for optimizing interfacial adhesion.

An economically-prudent pretreatment is a crucial first step towards realization of the industrial lignocellulosic biorefinery. The aim of this study was to utilize lignocellulosic biomass to co-produce xylo-oligosaccharides (XOS) and glucose starting from a novel self-providing xylonic acid (XA) acidolysis method. Based on the optimization results of main acidolysis pretreatment parameters by uniform design experiments, we found that among various lignocellulosic materials, the highest yield of XOS from xylan was 54.16% with corncob, followed by 39.19% with wheat straw, 29.01% with corn straw and 30.23% with poplar sawdust. By effective degradation and removal of xylan constituents with XA acidolysis, enzymatic hydrolysabilities of inert cellulose constituents of corn cob, corn straw, wheat straw and poplar sawdust were achieved to 100%, 72.94%, 75.35% and 38.97%. Comparative mass balance diagrams of xylan and cellulose reveal that XA acidolysis pretreatment is environmental-friendly and effective for three agricultural residues, apart from woody poplar., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

The inter-particle interference of lignocellulosic materials describes the order of the macromolecules at a larger size scale, which can give information about the pore structure, and interface of cellulose and lignin. The pore structure and interface influence the rate of enzymatic hydrolysis and thermal decomposition in cellulosic ethanol manufacturing. In this study, the inter-particle interference of cellulose and lignin of three major categories of lignocellulosic materials: wood-based (cedar and oak), energy crop (bamboo), and agricultural or forestry waste (palm) were evaluated. Scanning electron microscopy (SEM) reveals morphological irregularities in the case of bamboo and palm, which may form nucleation sites for faster accessibility to enzyme molecules. Small-angle X-ray scattering (SAXS) shows increased power-law exponent for palm, suggesting a less clustered structure, which was consistent with the rough surface morphology as detected by the SEM. Differential Scanning Calorimetry (DSC) showed a higher temperature maximum for cedar and oak, which is indicative of higher intermolecular forces within their organic compounds, and could result in slower disintegration of the macromolecules during biochemical processing. This study will help to estimate the activity of the macromolecules and absorption capacity of lignocellulosic materials during biochemical processing., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The study of lignocellulosic materials calls for understanding the structure, and function of different cellulosic materials from diverse sources to scale-up cellulosic ethanol production. For the first time, a systematic assessment of the molecular and supramolecular structure highlighting the similarities and dissimilarities of three major categories of lignocellulosic materials: wood-based (cedar and oak), energy crop (bamboo), and agricultural or forestry waste (palm) are reported. The cellulose, hemicellulose, and lignin constituents were compared for their suitability in cellulosic ethanol production. FTIR showed structural variations within the functional groups with notable OH group in the palm and CC group in cedar. From the X-ray scattering, bamboo exhibited the highest crystallinity (49.5%), and palm showed the lowest crystallinity (22.6%) and crystallite size (2.6 nm). TGA revealed high cellulose amount and stable structure for cedar and oak, and the most unstable structure in the palm, which indicates a better cellulose/hemicellulose accessibility and biodegradability for enzymatic or chemical action in the palm. This comparative assessment can greatly facilitate material selection and component mixture, for developing an efficient and cost-effective biochemical process in ethanol manufacturing., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Lignocellulose-based processes for production of value-added products still face bottlenecks to attain feasibility. The key might lie on the biorefining of all lignocellulose main polymers, that is, cellulose, hemicellulose and lignin. Lignin, considered an impediment in the access of cellulose and normally considered for energy recovery purposes, can give a higher contribution towards profitability of lignocellulosic biorefineries. Organosolv pretreatment allows selective fractionation of lignocellulose into separate cellulose-, hemicellulose- and lignin-rich streams. Ethanol organosolv and wood substrates dominated the research studies, while a wide range of substrates need definition on the most suitable organosolv pretreatment systems. Techno-economic and environmental analyses of organosolv-based processes as well as proper valorization strategies of the hemicellulose-rich fraction are still scarce. In view of dominance of ethanol organosolv with high delignification yields and high-purity of the recovered cellulose-rich fractions, close R & D collaboration with 1st generation ethanol plants might boost commercialization., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Agricultural feedstocks (brewers' spent grain - BSG, corncob - CC, corn husk - CH, wheat straw - WS and Luffa sponge - LS) were pretreated by liquid hot water (LHW) in order to increase cellulose recovery and enzymatic saccharification. LHW-pretreatment resulted in hemicellulose solubilization, and solids enriched in cellulose. Chemical analysis showed different susceptibilities of the feedstocks to LHW-pretreatment and enzymatic hydrolysis. Pretreated feedstocks presented higher crystallinity (determined through X-ray diffraction) and thermal stability (determined through thermogravimetric analysis) than untreated feedstocks. SEM images confirmed the effect of LHW-pretreatment on structural changes. Moreover, enzymatic hydrolysis and cellulose conversion to glucose (CCG) were improved for pretreated feedstocks, with exception of LS. CCG (in relation to glucose potential on solids) followed the order: BSG>CH>WS>CC>LS. LHW-pretreatment showed to be a good technology to pretreat multi feedstocks and for improving the enzymatic hydrolysis of recalcitrant agricultural feedstocks to sugars, which can be further converted to ethanol-fuel and other value-added chemicals., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Background: Lignin is a naturally occurring and aromatic biopolymer with well-known antimicrobial and antioxidant properties. Thus, in this work, the use of cellulose nanofibers (CNF) and lignin to produce ultra-light aerogels for biomedical applications was studied. Aerogels containing varying amounts of lignin (0–30 wt%) and different concentrations of the crosslinking agent Fe3+ (25–100 mM) were developed. Results: The different bioaerogels were fully characterized and their physical, mechanical and bioactive properties analyzed. It was observed that the bioaerogels soluble fraction tends to decrease as the lignin content increases for the different Fe3+ concentrations, due to lignin–CNF interactions through hydrogen bonds. The bioaerogels containing lignin showed remarkable radical scavenging activity as the DPPH concentration decreased with time. This confirms the benefits of including lignin in bioaerogels to impart antioxidant properties. To study the suitability of the produced bioaerogels for controlled drug release, the release of tetracycline (TC) was studied. All of the bioaerogels released TC in a sustained manner for 6 h and presented similar profiles. However, the bioaerogels containing higher concentrations of crosslinker showed a higher release of TC. The TC loading conferred clear antimicrobial activity against S. aureus as expected, unlike the insignificant antimicrobial activity of the bioaerogels without TC. The biocompatibility of the samples was demonstrated for all materials produced (with and without TC loading) by the Kruskal–Wallis test with multiple comparisons. After observation of cell morphology, no significant differences were evident suggesting that the CNF–lignin bioaerogels present optimal biocompatibility for use in the biomedical and pharmaceutical industry. Conclusions: The CNF–lignin bioaerogels presented in this work highlights their promising application as biomedical applications, such as wound dressings due to their biocompatibility, antimicrobial and antioxidant properties, as well as their swelling and solubility properties. [ABSTRACT FROM AUTHOR]

Ball milling is a widely studied technique known for its effectiveness in processing lignocellulosic materials and generating nanocellulose. However, the importance of fiber swelling in facilitating the extraction of microfibrillated cellulose through ball milling remains largely unexplored. Here, we delve into the influence of ball milling on the morphological traits of cellulosic fibers with different water contents and their fibrillation. The introduction of water into the system disrupts both inter- and intra-molecular hydrogen bonds within the fiber microstructure, leading to rapid replenishment and water-fiber interactions that promote fiber swelling. Notably, softwood-derived bleached kraft pulp fibers, distinguished by their greater length compared to hardwood-derived counterparts, exhibit superior swelling potential while preserving fiber morphology. After 24 hours of ball-milling swollen fibers with a 90 % water content, the proportion of short fibers (<0.4 mm) increase significantly to 65.3 %, a substantial 42.7 % enhancement compared to non-milled fibers. Extended ball milling durations further improve transparency and mechanical strength of microfibrillated cellulosic network (paper). Transmittance at 550 nm reaches 85.3 % relative to ball milling for 24 hours, while mechanical tensile strength reaches 47.4 MPa relative to ball milling for 12 hours, a 144.3 % increase compared to non-milled fibers (19.4 MPa). These findings highlight the critical role of fiber swelling in enabling efficient mass production of high-quality microfibrillated cellulose via ball milling, presenting promising avenues for commercial-scale production across diverse value-added applications. • Fiber swelling in softwood pulp via ball milling boosts microfibrillated cellulose. • Crucial water disruption enhances fiber swelling via hydrogen bonds. • Water content decisively shapes cellulosic particle morphology during milling. • Promising commercial-scale potential across versatile applications. [ABSTRACT FROM AUTHOR]

After acidic and high-temperature pretreatment of lignocellulosic biomass, researchers find that some lignin-like substance appeared on the surface of cellulose, which is called pseudo-lignin. Pseudo-lignin can be formed through carbohydrate degradation or substitution reactions on the aromatic ring of lignin. Pseudo-lignin is identified as Klason lignin in compositional analysis, whereas in Py-GC-MS analysis, it is recognized as material derived from carbohydrates. Pseudo-lignin is an aromatic substance. Similar to lignin, it also affects enzymatic hydrolysis efficiency by blocking the enzymatic reaction sites of cellulose and non-productive adsorption with cellulases. In order to offer theoretical guidance and technical support for the advancement of cost-effective and efficient new pretreatment technology, this review summarizes the latest advancements in research concerning the origins of pseudo-lignin, its effects on enzymatic hydrolysis, and the strategies that inhibit pseudo-lignin formation. • Different pretreatment methods that result in the formation of pseudo-lignin are reviewed. • The specific mechanism of pseudo-lignin formation is clarified. • The deposition of pseudo-lignin inhibits enzymatic hydrolysis. • Measures to hinder the formation of pseudo-lignin are discussed. [ABSTRACT FROM AUTHOR]

Anaerobic digestion (AD) of animal manure converts only half of the organic material into biogas due to the presence of a significant amount of lignocellulosic materials in manure. In this study, alkaline thermal pretreatment was used for improving anaerobic digestion of residual manure fibers after AD. Anaerobic digestion of pretreated manure fibers was done in batch culture under mesophilic and thermophilic conditions. The results of the study showed that degradation of manure fibers was improved ca. 43.6% as a result of alkaline thermal pretreatment with 3% w/w NaOH added. Methane yield improved by 143.5 and 180.2% under mesophilic and thermophilic conditions, respectively. Compositional analysis of the effluent after AD showed the percentile conversion of 50.8% of cellulose, 59.5% of hemicellulose, 39.9% of acid-soluble and 21.7% of acid-insoluble lignin to methane under mesophilic conditions. Under thermophilic conditions, 57.3% of cellulose, 70.1% of hemicellulose, 39.4% of acid-soluble and 19.4% of acid-insoluble lignin were converted to methane. The result showed that alkaline thermal pretreatment of manure fibers can enhance the performance of AD while shortening the time needed to recover the maximum amount of biogas from AD. [ABSTRACT FROM AUTHOR]

As the rapid increasing demand for electrical energy in the world, the research on electrical energy storage becomes urgent and crucial, especially for these ones with the features of cost-effectiveness, high safety and outstanding performance. Aqueous zinc ion batteries (AZIBs) are regarded as environmentally friendly, safe, reliable, and promising devices for electrochemical energy storage systems. However, a variety of challenges such as zinc dendrite formation, corrosion and hydrogen evolution must be addressed for the practical, widespread application of AZIBs. Recently, there has been notable interest in utilizing renewable, biodegradable, and cost-effective lignocellulosic materials to address these challenges, as they have the potential to significantly improve the electrochemical performance of AZIBs. However, there is a lack of comprehensive and systematic summary, as well as a gap in theoretical analysis, on the role of lignocellulosic materials in improving AZIBs performance. The present review covers the development, concept, advantages, and challenges of AZIBs. The most recent advancements and progress on the lignocellulosic materials (including cellulose, lignin, and hemicelluloses) as electrodes, electrolytes and separators for AZIBs applications are summarized. A perspective on existing challenges, potential solutions, and promising prospects of lignocellulosic materials is outlined, aiming to provide the research community with essential technical insights that could drive the commercialization of green and sustainable lignocellulosic materials in high-performance AZIBs. [Display omitted] • The advantages and current challenges of AZIBs have been systematically discussed. • The recent progress of developing lignocellulosic materials for AZIBs has been reviewed. • The strategies for improving the performance of AZIBs via incorporating lignocellulosic materials have been summarized. • The challenges and perspectives in developing lignocellulosic materials for advanced AZIBs have been addressed. [ABSTRACT FROM AUTHOR]

A set of imidazolium-based ionic liquids: [C4mim][PF6], [C4mim][BF4], [C4mim][Cl], [C4mim][CF3COO], [C4mim][NTf2], [C4mim][OMs], [C4mim][Br], and [C4mim][OAc], was studied by molecular dynamics simulations to elucidate their solvent behavior around a crystallite model of cellulose I β , through atomistic interactions and the degree of departure of its thermodynamic properties from their solvent pure phase. These departure changes were correlated with experimental values of the Kamlet-Taft solvent basicity parameter, and it was found that, even at room temperature, density changes, and vaporization enthalpy changes can be correlated with the capacity of ionic liquids for the preconditioning of the cellulose crystallite. Hydrogen bond occupancies indicate that ionic liquids can disrupt external chains of the cellulose crystallite by replacing and reducing the strong O 6 - H ⋯ O 2 / O 3 hydrogen bonds by weak hydrogen bonds such as O 6 - H ⋯ O 4 along the interchain network. Also, radial distribution functions indicated that structural changes in the cellulose-ionic liquid mixtures did not depart significantly with respect to the pure IL structure. The results of the free energy of solvation calculations for a cellulose chain, presented the following trend: [C4mim][Cl] > [C4mim][OAc] > [C4mim][CF3COO] > [C4mim][Br] > [C4mim][OMs] > [C4mim][BF4] > [C4mim][PF6] > water > [C4mim][NTf2]. It is important to emphasize, that the focus of this work was not the cellulose dissolution, but instead, the solvent behavior and cellulose preconditioning within each IL at room temperature. Our results can provide insights about the preconditioning stage of cellulose at low temperature, useful in the development of lignocellulosic materials and valuable cellulose derivatives by means of low energy requirements. [ABSTRACT FROM AUTHOR]

Cellulose is an organic compound belonging to polysaccharides. This biopolymer is made of glucose subunits. This compound plays an essential role in the structure and strength of plants. This polymer has biodegradable, biocompatible, and renewable properties. Agricultural wastes are excellent sources for cellulose extraction. Agricultural wastes are lignocellulosic materials, and cellulose and lignin are the main components of these wastes. Millions of tons of agricultural waste are thrown away and burned yearly. This large amount of waste leads to environmental pollution and waste of renewable energy resources. Upgrading such waste by developing innovative products such as cellulose nanomaterials and nanocomposites can have high environmental and economic benefits. The intelligent use of agricultural waste as a rich source of cellulose can be primarily responsible for the increase in population and industrialization of countries. Optimal cellulose extraction from agricultural waste can be widely used in various fields of agriculture, industry, medicine, and energy. Different chemical, physical, physicochemical, and biological methods have been presented to extract cellulose and its derivatives from agricultural waste. In this review, we will discuss the position and importance of cellulose, the importance of agricultural waste in the extraction of cellulose, and the use of extracted cellulose from agrarian wastes in various sources. • Agricultural wastes as an excellent source for cellulose extraction. • The use of agricultural waste intelligently to extract cellulose and use it in various industries. • Cellulose extracted from agricultural waste as a natural biocompatible and degradable polymer can greatly interest agriculture. [ABSTRACT FROM AUTHOR]

Large amounts of lignin residue is expected in the future when biorefineries for producing biofuels and bio-products will increase in numbers. It is, therefore, valuable to find solutions for using this resource for the sustained production of useful bioenergy or bio-products. Anaerobic digestion could potentially be an option for converting the biorefinery lignin into a valuable energy product. However, lignin is recalcitrant to biodegradation under anaerobic conditions unless the structure is modified. Wet oxidation followed by steam explosion (wet explosion) was previously found to make significant changes to the lignin structure allowing for biodegradation under anaerobic conditions. In this study, we examine the effect of wet explosion pretreatment for anaerobic digestion of wheat straw lignin under mesophilic (37 °C) conditions. Besides the biorefinery lignin produced from wheat straw, untreated lignin was further tested as feed material for anaerobic digestion. Our results showed that wet exploded lignin pretreated with 2% NaOH showed the highest lignin degradation (41.8%) as well as the highest methane potential of 157.3 ± 9.9 mL/g VS. The untreated lignin with no pretreatment showed the lowest methane yield of 65.8 ± 4.8 and only 3.5% of the lignin was degraded. Overall, increased severity of the pretreatment was found to enhance anaerobic degradation of lignin.

Corn cob is one of lignocellulosic material used for bioethanol production due to its high content of cellulose which can be converted into glucose through enzymatic hydrolysis. Unfortunately, the hydrolysis process is time consuming and the yield is relatively low. It is necessary to develop a more efficient process by applying optimum conditions. The objective of this research is to study the effect of the substrate concentration and the stirring rate on the amount of the glucose produced, to optimize these parameters and to derive a kinetic model of the enzymatic hydrolysis process studied. Pre-treated corn cobs and multiple enzymes (Cellic® C-Tec2 and Cellic® H-Tec2 from Novozymes) are used. The results show that the higher substrate concentration and the higher stirring rate lead to a higher amount of glucose. However, if the stirring rate is greater than 150 rpm, the enzymes activity decreases as they are sensitive to a mechanical stress. The optimum values of the substrate concentration and the stirring rate in case of corn cobs enzymatic hydrolysis are equal to 15 % (w/v) and 150 rpm, respectively. The kinetics of the process studied is well described by the model of Yi Zhouliang and E. Barson leading to values of Vmax and KM of 0.0043 mg/ml h and 2.856 mg/ml, correspondingly. [ABSTRACT FROM AUTHOR]

The cost of bioethanol production from lignocellulosic materials is relatively high because the additional processes of delignification and saccharification are required. Consolidated bioprocessing (CBP) simultaneously uses the multiple processes of delignification, saccharification, and fermentation in a single reactor and has the potential to solve the problem of cost. Some wood-degrading basidiomycetes have lignin- and cellulose-degrading abilities as well as ethanol fermentation ability. The white rot fungus Schizophyllum commune NBRC 4928 was selected as a strong fermenter from a previous study. The lignin-degrading fungus Bjerkandera adusta and polysaccharide-degrading fungus Fomitopsis palustris were respectively added to S. commune ethanol fermentations to help degrade lignocellulosic materials. Bjerkandera adusta produced more ligninase under aerobic conditions, so a switching aeration condition was adopted. The mixed culture of S. commune and B. adusta promoted direct ethanol production from cedar wood. Fomitopsis palustris produced enzymes that released glucose from both carboxymethylcellulose and microcrystalline cellulose. The mixed culture of S. commune and F. palustris did not enhance ethanol production from cedar. The combination of S. commune and cellulase significantly increased the rate of ethanol production. The results suggest that CBP for ethanol production from cellulosic material can be achieved by using multiple fungi in one reactor. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the capacity a cellulolytic complex produced by Rhizopus oryzae has to provide functional compounds from lignocellulosic material. Its characterization upon soybean meal (SBM) and corn husk (CH) was carried out. The effect was estimated in terms of cellulose reduction and protein and starch digestibility, besides the content of phenolic compounds (PC) and their profiles. Enzymatic hydrolysis caused 34% cellulose reduction in SBM whereas, in CH, it was 55%. In CH, the reduction promoted PC release (21%). The greatest change in the antioxidant activity after hydrolysis was found in phenolic compounds soluble in methanol (PCSM), a fact that could be attributed to concomitant reduction in ferulic acid and increase in hydroxybenzoic acid. In SBM, the activity of the cellulolytic complex caused increases in protein (74%) and starch (95%) digestibility. Therefore, available protein in SBM can be used as food supplement and thickener whereas PC derived from CH may be applied as food additive. [ABSTRACT FROM AUTHOR]

The Brazilian savanna, known as the Cerrado, is a biome with a high degree of endemism, with the potential to house many microorganisms suitable for biotechnological exploitation, especially fungi. The Cerrado soil, which is usually acidic, is a favorable environment for the growth of fungi capable of degrading lignocellulosic materials. The aim of the present study was to isolate cellulolytic filamentous fungi native to the Cerrado. Samples of soil and leaf litter were collected in three points of Cerrado State Park, located in the South of Brazil, during the rainy season in September 2014. Samples were stored in sterile plastic bags, transported at room temperature and kept at 4 °C for three days. Filamentous fungi were isolated by successive inoculations in PDA (maintained at 30 °C). Cellulase activity was tested in CMC (carboxymethyl cellulose) medium and lipase activity was assessed in medium containing phenol red and tween 20 (incubated at 37 °C), and in medium supplemented with Rhodamine B (kept at 30 °C). We isolated a total of 28 strains, 25 produced cellulase, detected with lugol in strains grown in CMC medium. The isolates were identified morphologically (color, form of growth) and by sequencing of the 18S rRNA region, with both techniques producing congruent results. One strain of Colletotrichum boninense and one strain of Trichoderma sp., both isolated from soil samples, presented the highest cellulolytic activity. All strains exhibited lipolytic activity, with enzyme production and activity influenced by temperature. The present study revealed new strains of known filamentous fungi that can be applied in biomass degradation. These strains are suitable for optimization of culture conditions, which could lead to the economic feasibility of the process. Rev. Biol. Trop. 66(1): 237-245. Epub 2018 March 01. [ABSTRACT FROM AUTHOR]

Sorption capacity toward humic acids was studied for a number of lignocellulosic materials with different structures and chemical compositions. The values of sorption capacity of the materials toward humic acids were determined taking into account the desorption process. In addition to physical sorption due to porosity, a more considerable contribution to humic acid binding is made by chemical sorption provided by the lignin component of the plant cell wall structure. [ABSTRACT FROM AUTHOR]

BACKGROUND Rice straw is an attractive lignocellulosic material for ethanol production, since it is one of the most abundant renewable resources. It generally has high cellulose and hemicellulose contents that can be readily hydrolysed into sugars for subsequent ethanol fermentation. The pretreatment method plays an important role in increasing the efficiency of enzymatic saccharification, thereby making the whole process economically viable. Torrefaction is an appropriate pretreatment technique for enhancing the enzymatic reaction and subsequent ethanol production. RESULTS The effects of two important parameters, i.e. residence time (20, 40 and 60 min) and temperature (160, 180, 200, 220, 240 and 260 °C), were studied under an inert atmosphere. The highest yield of 351 ± 5.49 mg g−1 total sugars was obtained after torrefaction treatment at 220 °C for 40 min, representing a 60.68% increase compared with the untreated sample. Based on ethanol studies conducted on rice straw, this estimated quantity of sugars could produce 150 ± 2.40 mg g−1 ethanol, a 50.67% increase compared with the untreated sample under anaerobic conditions. The fermentation rate was enhanced by adding 0.4 mmol L−1 benzoic acid. CONCLUSION The use of this waste material could reduce competition with food materials for ethanol production. It can be considered as an alternative sustainable waste management option. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Abstract: In this work, dilute sulphuric acid prehydrolysis of residual empty pods of Moringa oleifera fruits was investigated as pretreatment for enzymatic hydrolysis of cellulose. In experiments performed at 130–190°C for 10–30min, corresponding to a severity range between log R o =1.9 and log R o =4.2, the effect of pretreatment conditions on the recovery of polysaccharides and on the enzymatic convertibility of cellulose was evaluated. Overall cellulose recovery was above 95% in the pretreatments performed at 130 and 160°C, and between 87 and 90% in the pretreatments at 190°C, while xylan recovery in the most severe pretreatments was only 24.7–50.2%. The highest sugar concentration in the acid prehydrolysates (15.0g/L) was obtained in the pretreatment performed at 160°C and 20min. The formation of degradation products was low at mild pretreatment conditions, but it increased with the severity. Furfural concentration reached 4.04g/L at log R o =3.1 and decreased again with a further increase of the pretreatment severity. HMF, formic acid and levulinic acid were formed only in the most severe pretreatments. The pretreatment was effective for improving the enzymatic hydrolysis of cellulose, and the highest conversion (84.3%) was achieved in the material pretreated at mid severity (log R o =3.1). [Copyright &y& Elsevier]

Abstract: Rice hulls (RH) and bean hulls (BH) were subjected to prehydrolysis treatments, to define the optimum conditions for producing a high percentage of hydrolyzed hemicellulose with a small or moderate degradation of the cellulosic portion. The hydrolysis experiments were performed using hydrochloric and sulfuric acids in concentrations ranging from (0.5 to 5)% (w/w) at 120°C for 90min and 10% consistency. The effects of different temperatures (80 to 120°C) and time (30 to 120min) on acid hydrolysis of lignocellulosic materials were recorded. It was found that, the optimum condition to hydrolyze the lignocellulosic materials (RH) and (BH) are 2% (w/w) of mineral acid at 120°C for 90min and 10% consistency. The cellulose crystallinity index in the different types of lignocellulosic materials with and without acid treatment, were increased from 0.32 to 0.46 in case of RH and from 0.43 to 0.61 in case of BH. Due to the lignin depolymerization during the pretreatment process, the relative absorbency of the methoxyl group and the aromatic rings bands were lowered for the pretreated than the untreated lignocellulosic materials. Also, the band at 1730cm−1 which is attributed to carbonyl groups of uronic acids was lowered due the hemicellulose hydrolysis. [Copyright &y& Elsevier]

Large amounts of lignin residue is expected in the future when biorefineries for producing biofuels and bio-products will increase in numbers. It is, therefore, valuable to find solutions for using this resource for the sustained production of useful bioenergy or bio-products. Anaerobic digestion could potentially be an option for converting the biorefinery lignin into a valuable energy product. However, lignin is recalcitrant to biodegradation under anaerobic conditions unless the structure is modified. Wet oxidation followed by steam explosion (wet explosion) was previously found to make significant changes to the lignin structure allowing for biodegradation under anaerobic conditions. In this study, we examine the effect of wet explosion pretreatment for anaerobic digestion of wheat straw lignin under mesophilic (37 °C) conditions. Besides the biorefinery lignin produced from wheat straw, untreated lignin was further tested as feed material for anaerobic digestion. Our results showed that wet exploded lignin pretreated with 2% NaOH showed the highest lignin degradation (41.8%) as well as the highest methane potential of 157.3 ± 9.9 mL/g VS. The untreated lignin with no pretreatment showed the lowest methane yield of 65.8 ± 4.8 and only 3.5% of the lignin was degraded. Overall, increased severity of the pretreatment was found to enhance anaerobic degradation of lignin. [ABSTRACT FROM AUTHOR]

• A staged TGA setup in a combined nitrogen and oxygen atmosphere enables wood analysis. • A model for the quantification of cellulose, xylan and lignin in polymer mixtures was developed. • Three polymer mixtures representing typically compositions in natural wood were analyzed. • The deviation in polymer fractions between model and experiment was max. 1.37%. • The model was successfully validated by comparison with values from chemical analysis. The storage of wood chips is associated with high dry matter losses and changes in raw material properties due to microbiological-chemical degradation processes. For a better understanding of degradation processes and their effect on wood components, very labor intensive chemical analysis of a large number of wood samples over a storage period of 6 to 9 months is necessary. The thermogravimetric analysis (TGA) of wood samples offers the possibility to considerably reduce the analysis effort while at the same time achieving a high repeat accuracy. For this purpose, a method was first developed in which the determination of characteristic values for wood analysis is possible in a staged TGA setup in a combined nitrogen and oxygen atmosphere. Based on these characteristic values, a model for the quantification of cellulose, xylan and lignin in polymer blends was developed and three polymer blends representing a broad spectrum of naturally occurring compositions in wood were analyzed to validate the model. The deviation between the polymer fractions determined by the model and used in the experiment was max. 1.37%. The developed model was then transferred to the analysis of extract-free poplar wood samples. The model results were validated by comparison with chemical analysis (NREL) and literature values. This comparison has shown that the wood constituents under consideration can be determined with sufficient accuracy using the new method. The developed method can thus serve as a basis for the development of a method for the continuous monitoring of degradation processes in wood chip storage. [ABSTRACT FROM AUTHOR]