Lignocellulosic Residues Research Articles

Adequately converting poplar sawdust’s carbohydrates to furfural and glucose by employing acid oxidation pretreatment and solid acid catalysis

The utilization of lignocellulosic biorefinery residue has always been a major obstacle hindering its industrialization. In this work, the acetic acid assisted hydrogen peroxide pretreatment (AHP) and enzymatic hydrolysis was employed to facilitate the efficient bioconversion of poplar sawdust (PS), while simultaneously utilizing the solid acid catalyst (SA) synthesized from enzymatically hydrolyzed PS (EPS) for furfural production from prehydrolysate. It demonstrated that enzymatic hydrolysis of PS achieved a glucose yield of 61.3 %, which can be attributed to the effective removal of xylan and lignin through AHP pretreatment. The structural characterization revealed that SA-EPS exhibited a higher pore density, more acidic sites, and an increased presence of acidic groups compared with SA prepared from PS. Ultimately, the utilization of SA-EPS significantly augmented furfural yield and selectivity to 54.3 % and 64.1 %, respectively. By successfully synthesizing SA using lignin-rich EPS, the value-added benefits and increased efficiency have been achieved in biorefinery processes.

Exploring industrial lignocellulosic waste: Sources, types, and potential as high-value molecules

Lignocellulosic biomass has a promising role in a circular bioeconomy and may be used to produce valuable molecules for green chemistry. Lignocellulosic biomass, such as food waste, agricultural waste, wood, paper or cardboard, corresponded to 15.7% of all waste produced in Europe in 2020, and has a high potential as a secondary raw material for industrial processes. This review first presents industrial lignocellulosic waste sources, in terms of their composition, quantities and types of lignocellulosic residues. Secondly, the possible high added-value chemicals obtained from transformation of lignocellulosic waste are detailed, as well as their potential for applications in the food industry, biomedical, energy or chemistry sectors, including as sources of polyphenols, enzymes, bioplastic precursors or biofuels. In a third part, various available transformation treatments, such as physical treatments with ultrasound or heat, chemical treatments with acids or bases, and biological treatments with enzymes or microorganisms, are presented. The last part discusses the perspectives of the use of lignocellulosic waste and the fact that decreasing the cost of transformation is one of the major issues for improving the use of lignocellulosic biomass in a circular economy and green chemistry approach, since it is currently often more expensive than petroleum-based counterparts.

Energy assessment and heat integration of biofuel production from bio-oil produced through fast pyrolysis of sugarcane straw, and its upgrading via hydrotreatment

Sugarcane processing is one of the most important economic activities in Brazil, producing ethanol and sugar for domestic and international markets. Utilising the lignocellulosic residues of this industry, specifically bagasse and straw, would increase the second-generation biofuel production without increasing the sugarcane planted area. Among the processes available, the fast pyrolysis is a thermochemical conversion process that produces mainly bio-oil, a liquid with several advantages over solid biomass, regarding transportation, pumping, storage, and handling. Moreover, the bio-oil can be upgraded to obtain biofuels of higher added-value. Among feasible upgrading technologies, the hydrotreatment is one of the most promising methods for eliminating the reactive functionalities of the bio-oil by removing oxygen or cracking large molecules in the presence of hydrogen; however, this comes at the expense of a significant hydrogen consumption. Thus, the aim of this study is to evaluate the biofuel production through the fast pyrolysis of sugarcane straw, followed by the upgrading of the produced bio-oil via hydrotreatment. The evaluation is carried out by way of energy and mass balances of the processes, performed using the software Aspen Plus. Furthermore, the possibilities of integrating the bio-oil production and upgrading into the conventional ethanol and sugar production process will also be assessed through heat integration, applying the Pinch analysis. Results showed the potential for renewable gasoline and diesel production with yields of 0.086 kg/kg of dry straw and 0.08 kg/kg of dry straw, respectively. Additionally, integrating the pyrolysis process, including the bio-oil upgrading, into the ethanol production process can achieve a liquid fuel production (ethanol, gasoline and diesel) of 2289.8 MJ/t cane, which represents an increase of 29 %, while the surplus electricity increases in 5.3 %, when compared to the conventional ethanol production plant.

Obtaining Cellulose Fibers from Almond Shell by Combining Subcritical Water Extraction and Bleaching with Hydrogen Peroxide.

Almond shell (AS) represents about 33% of the almond fruit, being a cellulose-rich by-product. The use of greener methods for separating cellulose would contribute to better exploitation of this biomass. Subcritical water extraction (SWE) at 160 and 180 °C has been used as a previous treatment to purify cellulose of AS, followed by a bleaching step with hydrogen peroxide (8%) at pH 12. For comparison purposes, bleaching with sodium chlorite of the extraction residues was also studied. The highest extraction temperature promoted the removal of hemicellulose and the subsequent delignification during the bleaching step. After bleaching with hydrogen peroxide, the AS particles had a cellulose content of 71 and 78%, with crystallinity index of 50 and 62%, respectively, for those treated at 160 and 180 °C. The use of sodium chlorite as bleaching agent improved the cellulose purification and crystallinity index. Nevertheless, cellulose obtained by both bleaching treatments could be useful for different applications. Therefore, SWE represents a promising green technique to improve the bleaching sensitivity of lignocellulosic residues, such as AS, allowing for a great reduction in chemicals in the cellulose purification processes.

Characterization of Several Pellets from Agroforestry Residues: A Comparative Analysis of Physical and Energy Efficiency

The use of agroforestry biomass provides several advantages, both from an environmental point of view, in terms of the mitigation of global warming, and in terms of a circular economy for agricultural or agroforestry companies that reuse pruning residues as a source of energy. However, even if the use of energy pellets resulting from the pruning residues of various agroforestry species has excellent potential for the valorization of agricultural by-products, the physicochemical characteristics of these pellets have been scarcely studied by the scientific community. In this context, this study aims to assess the valorization potential of various lignocellulosic material residues produced during agroforestry activities. The objectives of the study include evaluating the chemical and physical characteristics of pellets produced with different mixtures of agroforestry biomass (olive, citrus, black locust, poplar, paulownia, etc.) in order to determine the optimal pellet blend from an energy and physicochemical perspective. The results of this study demonstrate that this comprehensive analysis provides valuable information on the optimization of biomass mixtures for better energy valorization, addressing both compositional and combustion-related challenges. In fact, it is observed that the addition of citrus and olive biomass to the various mixtures increases their energy potential. Furthermore, all of the pellets analyzed are found to possess an adequate and useful durability index (PDI) for their handling during storage and transport operations. This study demonstrates that olive and citrus pruning residues can be used to improve biomasses that have poor suitability in energetic, physical, and chemical terms. Further studies could be useful to understand which specific interaction mechanisms have an influence on emissions in order to optimize mixtures using different biomass sources for sustainable energy production.

Bioethanol Production from Citrus limon (Citrus) Peel Substrate Using Aspergillus Niger and Saccharomyces Cerevisae

Study’s Excerpt An approach to optimizing bioethanol production from lemon peel waste is presented. A combination of Aspergillus niger for enzymatic hydrolysis and Saccharomyces cerevisiae for fermentation were employed and specific physicochemical conditions—such as a pH of 3.5, temperature of 30°C, and 96-hour fermentation period—that maximize bioethanol yield and fermentation efficiency were highlighted. Citrus limon peel has a potential of becoming sustainable bioethanol source that could contributes to renewable energy development. Full Abstract The consumption of petroleum products is marred by the inconveniences of environmental pollution and the emission of greenhouse gases, which are responsible for global warming. Excessive use of fossil fuel has resulted in climate change, the elevation of the greenhouse gas effect, etc., contributing to the search for renewable sources of energy in harmony with the world’s energy needs. Although bioconversion of lignocellulose residue has received much attention, most plant biomass has not been fully exploited to meet human energy needs. Among these alternative energy carriers, ethanol receives great attention. This study aims to determine the optimal conditions for the production of bioethanol from lemon peel using Aspergillus Niger and Saccharomyces cerevisae. Aspergillus niger and Saccharomyces cerevisiae were isolated using the streak plate method and identified macroscopically and microscopically. The cellulose hemicellulose and lignin contents of the substrates were determined, and after that, the substrates were pretreated with 5% sulfuric acid and then subjected to enzymatic hydrolysis using Aspergillus niger. Subsequently, the reducing sugar content of the hydrolysate was determined, followed by fermentation using Saccharomyces cerevisae. The percentage of bioethanol produced, as well as the fermentation efficiency (%), were calculated. Analysis of Variance was employed to determine statistically significant differences among the determined parameters. The cellulose, hemicellulose, and lignin contents of Citrus Limon were found to be 32.00%, 4.99%, and 9.80%. Pretreatment increased the cellulose content from 23.00% to 32.00%. The highest reducing sugar content, 6.63 g/L,, was recorded after hydrolysis for 96 hours. Fermentation using Saccharomyces cerevisae yielded 19.20% of bioethanol from Citrus limon with a fermentation efficiency of 38.42%, respectively. The Optimum fermentation conditions recorded were a time of 96hrs, pH of 3.5, temperature of 30oC and amount of substrate of 15g. The combination of these parameters produced a bioethanol yield of (22.90%) and a fermentation efficiency of 44.44%, respectively. This research revealed the potential of Citrus limon peel waste as a substrate for bioethanol production and optimized the physicochemical parameters for the fermentation.

Exploration of Trichoderma reesei as an alternative host for erythritol production

BackgroundErythritol, a natural polyol, is a low-calorie sweetener synthesized by a number of microorganisms, such as Moniliella pollinis. Yet, a widespread use of erythritol is limited by high production costs due to the need for cultivation on glucose-rich substrates. This study explores the potential of using Trichoderma reesei as an alternative host for erythritol production, as this saprotrophic fungus can be cultivated on lignocellulosic biomass residues. The objective of this study was to evaluate whether such an alternative host would lead to a more sustainable and economically viable production of erythritol by identifying suitable carbon sources for erythritol biosynthesis, the main parameters influencing erythritol biosynthesis and evaluating the feasibility of scaling up the defined process.ResultsOur investigation revealed that T. reesei can synthesize erythritol from glucose but not from other carbon sources like xylose and lactose. T. reesei is able to consume erythritol, but it does not in the presence of glucose. Among nitrogen sources, urea and yeast extract were more effective than ammonium and nitrate. A significant impact on erythritol synthesis was observed with variations in pH and temperature. Despite successful shake flask experiments, the transition to bioreactors faced challenges, indicating a need for further scale-up optimization.ConclusionsWhile T. reesei shows potential for erythritol production, reaching a maximum concentration of 1 g/L over an extended period, its productivity could be improved by optimizing the parameters that affect erythritol production. In any case, this research contributes valuable insights into the polyol metabolism of T. reesei, offering potential implications for future research on glycerol or mannitol production. Moreover, it suggests a potential metabolic association between erythritol production and glycolysis over the pentose phosphate pathway.

Biocalorimetry-aided monitoring of fungal pretreatment of lignocellulosic agricultural residues

The present study aimed to investigate whether and how non-invasive biocalorimetric measurements could serve for process monitoring of fungal pretreatment during solid-state fermentation (SSF) of lignocellulosic agricultural residues such as wheat straw. Seven filamentous fungi representing different lignocellulose decay types were employed. Water-soluble sugars being immediately available after fungal pretreatment and those becoming water-extractable after enzymatic digestion of pretreated wheat straw with hydrolysing (hemi)cellulases were considered to constitute the total bioaccessible sugar fraction. The latter was used to indicate the success of pretreatments and linked to corresponding species-specific metabolic heat yield coefficients (YQ/X) derived from metabolic heat flux measurements during fungal wheat straw colonisation. An YQ/X range of about 120 to 140 kJ/g was seemingly optimal for pretreatment upon consideration of all investigated fungi and application of a non-linear Gaussian fitting model. Upon exclusion from analysis of the brown-rot basidiomycete Gloeophyllum trabeum, which differs from all other here investigated fungi in employing extracellular Fenton chemistry for lignocellulose decomposition, a linear relationship where amounts of total bioaccessible sugars were suggested to increase with increasing YQ/X values was obtained. It remains to be elucidated whether an YQ/X range being optimal for fungal pretreatment could firmly be established, or if the sugar accessibility for post-treatment generally increases with increasing YQ/X values as long as “conventional” enzymatic, i.e. (hemi)cellulase-based, lignocellulose decomposition mechanisms are operative. In any case, metabolic heat measurement–derived parameters such as YQ/X values may become very valuable tools supporting the assessment of the suitability of different fungal species for pretreatment of lignocellulosic substrates.Key points• Biocalorimetry was used to monitor wheat straw pretreatment with seven filamentous fungi.• Metabolic heat yield coefficients (YQ/X) seem to indicate pretreatment success.• YQ/X values may support the selection of suitable fungal strains for pretreatment.

Harnessing Lignocellulosic Waste‐Derived Carbon Materials for Green Electrochemical Applications

AbstractPhytoremediation and constructed wetlands are widely employed processes for the decontamination of soils and waters. These sustainable, effective, and cost‐efficient technologies rely solely on the use of plants. However, the application of these processes results in the accumulation of lignocellulosic residues, like it occurs with natural wetlands, which present a significant challenge due to the potential entry into the food chain of the adsorbed pollutants or the risk of initiating uncontrolled fires due to the accumulation of dead biomass. Nevertheless, rather than being perceived as a drawback, this can be seen as a potential source of materials. Carbonaceous materials are gaining increasing significance in the field of electrochemistry, normally improving their features through some type of thermal treatment. In this study, different types of thermal treatments applied to lignocellulosic wastes are reviewed pointing out pyrolysis and hydrothermal carbonization (HTC). Additionally, four environmental and energy electrochemical applications where this type of waste has been used as precursors of electrode materials are briefly examined: energy storage (supercapacitors, Li−Na‐ion batteries), hydrogen production (H2), microbial fuel cells (MFCs) and hydrogen peroxide (H2O2) production. Recent research findings, as discussed throughout this review, suggest a promising future for the utilization of lignocellulosic waste in electrochemical applications.

Biochemical, functional and antioxidant dynamics potential of higher fungi cultivated on agro-industrial residues. Part I: Cultures on media supplemented with yeast extract, gypsum and commodity vegetable oils

Mushroom cultivation is an implementation of the industrial biotechnology in the valorization of various lignocellulosic materials. In the present study, common lignocellulosic residues (wheat straw - WS and barley and oats straw - BOS) were supplemented with ‘novel’ compounds (sunflower and corn oil, yeast extract and CaSO4⋅2H2O) and their impact on the biochemical properties (composition of intra-cellular polysaccharides - IPSs, proteins, lipids, glucans, tocopherol content, carbohydrates and fatty acids composition), total phenolic compounds (TPCs) and the antioxidant activity of Pleurotus ostreatus and Pleurotus eryngii mushrooms, cultivated in ‘bag-logs’, was evaluated. Results revealed that supplements enhanced IPSs in carposomes cultivated on BOS substrates and the most positive were corn oil 2%, w/w and CaSO4⋅2H2O for P. ostreatus and P. eryngii, respectively (50.86 and 57.65%, w/w). In all treatments, there was a variety in the carbohydrate's composition and a great production of glucans (40.67–62.15%, w/w), especially of the bioactive β-glucans (32.10–61.93%, w/w) in the stipes of both species. Significant protein content was detected in P. ostreatus and P. eryngii carposomes grown on substrates with yeast extract (28.99 and 30.09%, w/w; WS and 29.49 and 24.94%, w/w; BOS). Although mushrooms presented a low lipid content in general, high values of fat content were observed for both species when cultivated on BOS substrate supplemented with sunflower and corn oil (4.54–6.58%, w/w). The nutritional value of mushrooms was comparable between the two flushes. The greatest amount of TPCs were detected in supplemented WS (22.31–35.30 mg gallic acid equivalents/g d.w.) and BOS (21.03–41.74 mg gallic acid equivalents/g d.w.) with CaSO4⋅2H2O, in all parts of mushrooms and a strong antioxidant activity and tocopherols production, in all treatments. A higher quantity of lipids, antioxidant activity and reducing power was present in the pilei rather than the stipes, while the latter were richer in IPSs, regardless of the supplement's presence. Therefore, the outlined supplemented substrates could be used to produce mushrooms with high nutritional and medicinal values.

Lignocellulosic Residues from Fruit Trees: Availability, Characterization, and Energetic Potential Valorization

Reducing the carbon footprint of energy production is one of the most pressing challenges facing humanity today. Lignocellulosic biomass residues from fruit production industries show promise as a viable energy source. This paper presents a study of the Italian context concerning the utilization of orchard lignocellulosic residues for energy production as electricity or bioethanol. The potential of various orchard residues was assessed through chemical and physical analyses, and an equivalent electrical energy of about 6441.62 GWh or an amount of 0.48 Mt/y of bioethanol was obtained based on the average annual dry residue mass availability of about 3.04 Mt/y. These data represent 9.30% of the national electrical energy production from renewable sources, as well as 6.21% of the Italian demand for gasoline in 2022. Electricity generation from these residues has shown its potential as a reliable and sustainable baseload power source, as well as a source of renewable transportation fuel. The studied process could be a valuable reference to expand these concepts on a global scale to achieve a greener and more sustainable energy future.

Isolation and Characterization of a Low-Temperature, Cellulose-Degrading Microbial Consortium from Northeastern China.

The lack of efficient ways to dispose of lignocellulosic agricultural residues is a serious environmental issue. Low temperatures greatly impact the ability of organisms to degrade these wastes and convert them into nutrients. Here, we report the isolation and genomic characterization of a microbial consortium capable of degrading corn straw at low temperatures. The microorganisms isolated showed fast cellulose-degrading capabilities, as confirmed by scanning electron microscopy and the weight loss in corn straw. Bacteria in the consortium behaved as three diverse and functionally distinct populations, while fungi behaved as a single population in both diversity and functions overtime. The bacterial genus Pseudomonas and the fungal genus Thermoascus had prominent roles in the microbial consortium, showing significant lignocellulose waste-degrading functions. Bacteria and fungi present in the consortium contained high relative abundance of genes for membrane components, with amino acid breakdown and carbohydrate degradation being the most important metabolic pathways for bacteria, while fungi contained more genes involved in energy use, carbohydrate degradation, lipid and fatty acid decomposition, and biosynthesis.

Biodegradable, UV-blocking, and antioxidant films from alkali-digested lignocellulosic residue fibers of switchgrass

The development of bio-friendly materials to replace single-use plastics is urgently needed. In this regard, cellulosic material from plants is a promising alternative. However, due to the risk of forest depletion, agricultural biomass stands out as a favorable choice. Toward this end, switchgrass, an underutilized grass, presents itself as a viable source of lignocellulose that can be turned into a bio-friendly material. Herein, lignocellulosic residue from switchgrass has been extracted using two different concentrations of NaOH (20% and 50% w/v), solubilized in aqueous ZnCl2 solution, and crosslinked with CaCl2 (200, 300, 400, and 500 mM) to prepare biodegradable films. The color, thickness and moisture, water solubility, water absorption, water vapor permeability, tensile strength and elongation, biodegradation, UV transmittance, and antioxidant activity of films have been studied. The films possess a high tensile strength of 14.7 MPa and elongation of 4.7%. They block UVB-radiation and hold antioxidant properties. They display good water vapor permeability of 1.410–1.6 × 10−11 gm−1s−1Pa−1 and lose over 80% of their weight at 30% soil moisture within 40 days. An increase in the CaCl2 amount decreased the water vapor permeability, elongation, UV transmittance, and biodegradation but increased the transparency, tensile strength and antioxidant property. Overall, films of alkali-digested lignocellulosic residue of switchgrass showed excellent potential to be used against lightweight plastics and support the circular economy.

A novel bio-based water reducer for concrete application: Facile process and techno-economic analysis of xylonate bioproduction from lignocellulosic residues

The xylonate was bioproduced directly from lignocellulosic residues, and the application properties of crude xylonate powder were investigated with a promising potential as a bio-based concrete water reducer. The overall integrated process was evaluated on the view of mass balance and techno-economic analysis using Aspen Plus modeling. 56 g/L of calcium xylonate (XA-Ca) can be obtained within 8 h from acidic corncob hydrolysate (ACH) at a 100 % yield with the whole-cell catalysis of Gluconobacter oxydans. At the addition of 0.2 wt% in the dry concrete content, XA-Ca powder and sodium xylonate powder prepared from pure xylose and ACH could reduce water used in concrete by 15 %, 14 %, 13 %, and 13 %, respectively. XA-Ca from ACH led to a 33% increase in concrete compressive strength and a 24% increase in concrete flexural strength at day 7 compared to the blank group. The techno-economic analysis showed the minimum XA-Ca powder price to be $ 0.806/kg which can be economically feasible. This study provides a practical and economical process prototype for the industrial concrete water reducer application of novel bio-based xylonate produced from lignocellulosic residues.

Biochemical changes, metal content, and spectroscopic analysis in sewage sludge composted with lignocellulosic residue using FTIR-MIR and FTIR-NIR.

The use of lignocellulosic residues, originating from sawdust, in composting sewage sludge for organic fertilizer production, is a practice of growing interest. However, few studies have explored the effect of the proportion of sawdust and sewage sludge raw materials on composting performance in the humification process. This study assessed the addition of sawdust in the sewage sludge composting process, regarding carbon content, presence of heavy metals, and humification of the organic compost. The experimental design employed was a randomized complete block design with five treatments featuring different proportions of organic residues to achieve C/N ratios between 30-1 (T1: 100% sewage sludge and 0% sawdust, T2: 86% sewage sludge and 14.0% sawdust, T3: 67% sewage sludge and 33% sawdust, T4: 55% sewage sludge and 45% sawdust, and T5: 46.5% sewage sludge and 53.5% sawdust) and five replications, totaling 25 experimental units. The addition of lignocellulosic residue in sewage sludge composting increased the levels of TOC and the C/N ratio, reduced the levels of pH, P, N, Na, Ba, and Cr, and did not interfere with the levels of K, Ca, Mg, S, CEC, labile carbon, and metals Fe, Zn, Cu, Mn, Ni, and Pb. The increase in the proportion of sawdust residue favored the degradation of aliphatic groups, increasing the presence of aromatic structures and reducing humification at the end of composting. The use of sawdust as a lignocellulosic residue in sewage sludge composting is a viable and efficient alternative to produce high-quality organomineral fertilizers.

Building a Greener Future: Advancing Concrete Production Sustainability and the Thermal Properties of 3D-Printed Mortars

The integration of waste materials in extrudable cement mixtures has the potential to make the construction industry more sustainable by reducing carbon footprints and developing eco-friendly materials. This along with advancements in 3D concrete printing (3DCP) provides engineering and architectural benefits by reducing material waste and costs. In this paper, the impact of waste incorporation on properties of mortar and concrete is examined. The use of waste materials, such as pumice, coal slag, agricultural lignocellulosic residues, and recycled rubber tyres, to improve thermal insulation and durability of cementitious composites is discussed. In addition, the incorporation of air-entraining admixtures with surfactant activity is explored for their indirect effect on thermal behaviour, pore size reduction, and enhancement in concrete properties. This review includes important topics such as a strength resistance to freezing and thawing, fire resistance, plasticising effect, and delay in cement hydration. These findings highlight the benefits of using diverse waste materials in construction, providing a multidimensional approach to waste management, cost optimization, and enhanced construction materials in the context of 3DCP.

Innovative carbon materials from lignocellulosic wastes for electrochemical hydrogen peroxide production: Bridging biomass conversion and material properties

This study aims to assess the electrochemical generation of hydrogen peroxide and hydroxyl radicals (*OH) using carbon cathodes synthesized from three different lignocellulosic residues, Phragmites australis (PA), Cladium mariscus (CM) and Typha domingensis (TD). These vegetal species are commonly used in natural wetlands and phytoremediation processes and can accumulate recalcitrant pollutants within these treatment processes, generating a waste that should be properly managed. To convert these residues into valuable carbon materials, they underwent hydrothermal carbonization (HTC) followed by either chemical activation with KOH or pyrolysis at 1000 ºC. The best results were obtained with chemically activated materials, yielding a maximum H2O2 concentration of 313 mg L−1 with the carbon cathode produced from PA. The specific surface area, oxygenated functional groups and presence of structural defects in carbonous structures, were key parameters related to a good performance as catalysts towards the 2e- Oxygen Reduction Reaction (ORR). It was also demonstrated, in comparison with previous studies, that the presence of heavy metals in the structure of the lignocellulosic residue enhanced the decomposition of H2O2 into *OH. However, in the study of the degradation of a model organic contaminant as methylene blue (MB), it was shown that these *OH were not the main contributors to degradation, as direct H2O2 chemical degradation and adsorption on the carbon materials played the most significant role. Therefore, the outstanding capacity of these lignocellulosic residues as catalysts for the electrogeneration of H2O2 was confirmed, suggesting their potential future application in advanced oxidation processes for water decontamination.

Valorization of lignocellulosic agave residues via pyrolysis and its use as adsorbent for methylene blue removal

Valorization of lignocellulosic agave residues via pyrolysis and its use as adsorbent for methylene blue removal

Enhancing Xylanase Production from Aspergillus tamarii Kita and Its Application in the Bioconversion of Agro-Industrial Residues into Fermentable Sugars Using Factorial Design

The endo-1,4-β-xylanases (EC 3.2.1.8) are the largest group of hydrolytic enzymes that degrade xylan, the major component of hemicelluloses, by catalyzing the hydrolysis of glycosidic bonds β-1,4 in this polymer, releasing xylooligosaccharides of different sizes. Xylanases have considerable potential in producing bread, animal feed, food, beverages, xylitol, and bioethanol. The fungus Aspergillus tamarii Kita produced xylanases in Adams’ media supplemented with barley bagasse (brewer’s spent grains), a by-product from brewery industries. The culture extract exhibited two xylanase activities in the zymogram, identified by mass spectrometry as glycosyl hydrolase (GH) families 10 and 11 (GH 10 and GH 11). The central composite design (CCD) showed excellent predictive capacity for xylanase production (23.083 U mL−1). Additionally, other enzyme activities took place during the submerged fermentation. Moreover, enzymatic saccharification based on a mixture design (MD) of three different lignocellulosic residues was helpful in the production of fermentable sugars by the A. tamarii Kita crude extract.

Cellulases production optimization and inductors evaluation in pretreated plantain rachis by Penicillium oxalicum

AbstractPretreated lignocellulosic residues are suitable substrates for cellulases production by filamentous fungi. In the current work, plantain rachis was pretreated with sequential acid and alkali and then used as the main carbon source for cellulases production. First, a full 23 factorial design and response surface methodology (RSM), based on central composite rotatable design (CCRD), were carried out to cellulases production media optimization from plantain rachis by Penicillium oxalicum. The cellulases production was evaluated in flasks and bioreactor scale; in parallel, the addition of possible cellulases inductors was evaluated in flasks: molasses, beer bran, oat bran, and wheat bran. Results from statistical analyses with a level of confidence of 95% demonstrated that the concentration of ammonium sulfate must be kept at 1.625 g/L. The optimum urea and yeast extract concentrations were 0.560 g/L and 0.250 g/L, respectively. Cellulases volumetric productivities were higher in instrumented bioreactor than in flasks: 78.03% for exoglucanase, 10.87% for endoglucanase, 1.58% for β‐glucosidase, and 44.36% for FPU. Therefore, P. oxalicum was able to produce cellulases from plantain rachis in flasks and bioreactor, and molasses was the additional inductor that presented an increment in cellulases activities: endoglucanase 15%, exoglucanase 81%, and β‐glucosidase 55%.