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The aim of this research was to investigate glucose yield from different sorts of biomass and their suitability for bioethanol production. The amount of glucose obtained from different samples was also compared with their cellulose, hemicellulose, lignin content and in some cases with harvesting time. Dilute acid pretreatment at temperature of 150°...
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... of many renewable energy resources, biomass is given high priority as it can be directly utilized for the production of various alternative transportation fuels, especially ethanol (Dwivedi et al., 2009). Ethanol is an attractive alternative fuel because it is a renewable resource and it is oxygenated, providing thus potential for reducing emissions in engines. In many areas of Estonian agriculture practical utilization of agricultural byproducts and biowaste is lacking. Moreover, biomass from the management of nature reserves is largely unused. Production of ethanol from cellulosic feedstock and its utilization as a substitute for gasoline could help in promoting rural development, reducing greenhouse gases, and achieving better energy independence (Demirbas & Bioethanol, 2005). The aim of this research was to investigate glucose yield from different sorts of biomass and their suitability for bioethanol production. Biomass species were chosen according to the principle that they should grow in Estonia, but should not compete with the food market. Cellulose is a linear polysaccharide which may consist of a few hundred to tens of thousands D – glucose monomers. It is found mostly in plant cell wall constructions. Cellulose is a water insoluble compound that is difficult to biodegrade. In nature, cellulose is degraded by bacteria and fungi which possess corresponding enzymes (Guenet & Cellulose, 2008). Microorganisms degrade cellulose primarily in to stages as follows: First, as seen in Fig. 1, cellulose is degraded into cellobiose which consists of two glucose monomers, and then it is further degraded into glucose. Hydrolysis of biomass was done by using a specific enzyme complex called Accellerase 1500, produced by Danisco U.S. Inc. Accellerase 1500 contains multiple enzyme activities, mainly exoglucanase, endoglucanase, hemi – cellulase and beta – glucosidase. It is produced by genetically modified strain of Trichoderma reesei. Trichoderma reesei is a mesofilic fungus that is found in tropical soils and produces different cellulose degrading enzymes (Vitikainen et al., 2010). Lignin is a complex chemical compound that is an integral part of the secondary cell wall of the plants. Lignin is one of the most slowly decomposing components of dead vegetation, contributing a major fraction of the material that becomes humus as it decomposes. Lignin is a cross-linked macromolecule, structure seen in fig. 2, with molecular masses over 10,000, being relatively hydrofobic and aromatic. Because of its cross-linking with the other cell wall components, it minimizes the accessibility of cellulose and hemicellulose to microbial enzymes ( Sjöström , 1993). Different plant species which grow in Estonia, but do not compete directly with the food market or animal feed, were chosen for research. Herbaceous biomass from 7 different species was investigated: hemp, sunflower, energy grass, reed, silage, Jerusalem artichoke ( Helianthus tuberosus ), and Miscanthus saccharifloris . All samples were harvested between August and October in 2010 from the experimental fields of Estonian University of Life Sciences, except for reed which was cut in October from Lake Kuremaa. Ash, hemicellulose, cellulose and lignin content of biomass samples was determined in Laboratory of Plant Biochemistry of Estonian University of Life Sciences as seen in Table 1. Standard methods of Association of Official Analytical Chemists (AOAC 973-18) and methods by the company Tecator (Fibre determination using the Fibertec M&I systems) were used for analysis. Jerusalem artichoke had two harvesting periods and both samples were analysed. Silage was pressed and then dried press cake was used for analysis. All samples were cut down to particle size of 3 – 5 cm and dried to a moisture content of less than 5%. Different methods have been used for biomass pretreatment. Very high conversion rates of cellulose to sugars of 70-90% are usually reported with AFEX (Ammonia Fiber Expansion) and steam explosion pretreatment methods. Both methods require quite severe operating conditions, temperature of 70- 200oC and pressure of 5-30 bar with AFEX, and temperature of 180- 240oC and pres sure of 10-40 bar with steam explosion. For degradation of cellulose into glucose in this research, dilute acid pretreatment followed by enzymatic hydrolysis was used. This method is simple and uses cheap chemicals and mild operating conditions. The downside of the method is lower conversion rate and a possibility of inhibitory byproducts formation. Pretreatment is achieved by breaking the lignin seal and hemicellulose sheathing over cellulose and by disrupting the crystalline structure of cellulose (Dien et al., 2006; Yang et al, 2009). The size of the samples was 75g of dried and milled biomass (moisture content < 5%) to which 750ml of 1% H 2 SO 4 solution was added. All samples were heated for t = 30 minutes at the temperature T = 150 ± 3oC and the pressure p = 5 bar. After the sample had cooled under 50oC, Ca(OH) 2 was added in order to regulate the pH = 4,5-5 because enzymes are inactivated when pH < 4 or if pH > 6. Pretreatment was followed by enzymatic hydrolysis with enzyme complex Accellerase 1500. -1 Enzymes were added to the sample with a concentration of 0,2ml g of biomass. Hydrolysis lasted for t = 48 hours under constant stirring and at the temperature T = 50oC. As a result most of the biomass (TS = 10%) was dissolved and turned into brown liquid. After the hydrolysis process, glucose concentration in all samples was measured reflectometrically by RQflex 10 reflectometer and Reflectoquant glucose & fructose test. D-glucose and D-fructose are converted into D-glucose-6-phosphate. This is oxidized by NAD under the catalytic effect of glucose-6-phosphate dehydrogenase to gluconate-6-phosphate. In the presence of diaphorase, the NADH formed in the process reduces a tetrazolium salt to blue formazan which is determined reflectometrically. At least 3 parallel samples were analyzed from every different biomass sort. Averaged results are used in figures and deviation is showed by vertical lines. Data was processed with programs Microsoft Excel and Graph Pad Prism 5. Glucose yield from different sorts of biomass and their suitability for bioethanol production was studied in this work. Results varied greatly between samples from different plant species. The results indicate that glucose yield depends directly on the cellulose content of the sample, as shown in Fig. 3. The higher the cellulose content, the higher is the glucose yield with two exceptions of sunflower and reed. Sunflower and Jerusalem -1 -1 artichoke (Oct.) gave the lowest glucose yield of 122.7g kg and 162.2g kg of biomass, the cellulose content of which was 34.06% and 20.95%, respectively. -1 Jerusalem artichoke (Aug.) gave a glucose yield of 194.1g kg , but it had a cellulose content of 25.99%. Cellulose and lignin content of a plant varies in time. A plant culture harvested in summer tends to have higher cellulose content and give better glucose yields than the same culture that is harvested in autumn (Bals et al., 2010). Sunflower has low cellulose content but quite high lignin and ash levels. Lignin minimizes the accessibility of cellulose to enzymes, resulting in lower glucose yield. Reed has high cellulose content but also high lignin and hemicellulose content, as shown in Fig. 4 and Table 1. This indicates that pretreatment has not removed hemicellulose completely and some of the remaining hemicellulose together with lignin is impeding enzymes from reaching the cellulose. The best glucose yield of -1 312.7g kg was obtained from hemp samples that had the highest cellulose concentration of 53.86%. The percentages of glucose yield from possible maximum values can be seen in Table 2. Jerusalem artichokes gave the highest yield of 77.42% and 74.70%, regardless of the harvesting time. This culture had the lowest cellulose content, but also the lowest lignin, hemicellulose and ash content. With few inhibiting factors, cellulose was easily accessible for degradation. The lowest yield percentage could be observed in sunflower and reed with 33.08% and 46.42%, respectively. Both cultures have high lignin content, but reed has also very high hemicellulose and cellulose content. In this case, the low yield percentage is possibly caused by inadequate pretreatment process. ...
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Citations
... It hinders the free access of cellulolytic enzymes due to its cross-linkages with other components of the cell wall. It has a very slow rate of decomposition but contributes a significant aspect to the materials that form humus [18]. Lignin comprises three basic monomers: p-coumaryl alcohol, coniferyl alcohol, and sinapyl alcohol. ...
Biofuels are clean and renewable energy resources gaining increased attention as a potential replacement for non-renewable petroleum-based fuels. They are derived from biomass that could either be animal-based or belong to any of the three generations of plant biomass (agricultural crops, lignocellulosic materials, or algae). Over 130 studies including experimental research, case studies, literature reviews, and website publications related to bioethanol production were evaluated; different methods and techniques have been tested by scientists and researchers in this field, and the most optimal conditions have been adopted for the generation of biofuels from biomass. This has ultimately led to a subsequent scale-up of procedures and the establishment of pilot, demo, and large-scale plants/biorefineries in some regions of the world. Nevertheless, there are still challenges associated with the production of bioethanol from lignocellulosic biomass, such as recalcitrance of the cell wall, multiple pretreatment steps, prolonged hydrolysis time, degradation product formation, cost, etc., which have impeded the implementation of its large-scale production, which needs to be addressed. This review gives an overview of biomass and bioenergy, the structure and composition of lignocellulosic biomass, biofuel classification, bioethanol as an energy source, bioethanol production processes, different pretreatment and hydrolysis techniques, inhibitory product formation, fermentation strategies/process, the microorganisms used for fermentation, distillation, legislation in support of advanced biofuel, and industrial projects on advanced bioethanol. The ultimate objective is still to find the best conditions and technology possible to sustainably and inexpensively produce a high bioethanol yield.
... It can be used to produce bioethanol, biodiesel, or biohydrogen as alternative fuels for automobiles (Wichmann and Wichtmann, 2009). Notably, unlike "first-generation" biofuels derived from food crops, reed represents a second-generation biofuel sourced from non-food biomass or agricultural waste such as maize.With pre-treatment to remove the lignin seal and hemicellulose sheathing, reed cellulose (31.5% hemicellulose and 49.4% cellulose) yields glucose for the production of biofuel (Tutt and Olt, 2011). ...
Climate change is a critical worldwide concern that affects every aspect of existence and all living beings. The study of climate change's impact on invasive species has piqued the interest of researchers worldwide due to the possible ramifications for biodiversity and vulnerable species protection. Phragmites australis (Cav.) Trin. Ex Steud. (Poaceae) is regarded as one of the most crucial invaders with a high tolerance for climate change impacts, particularly increased salinity, temperature, and atmospheric CO 2 , which may alter the surrounding ecosystems, and its uncontrolled spread may result in biodiversity deterioration. Because of its ecological importance and applications, common reed requires sustainable management to reap the majority of its benefits without damaging the environment, which requires a thorough understanding of its behavior in light of climate change. The following review article intends to investigate the response of the common reed to significant climate change factors including as salinity, temperature, and atmospheric CO 2 in Egypt, as well as to highlight rehabilitation solutions. Therefore, it is projected that the common reed population would continue to grow under the current climate change key drivers in Egypt, necessitating greater mitigation and adaption procedures from the government, academia, and society.
... On the other hand, hemicellulose contents of P. hysterophorus were almost similar to those in wheat straw and sugarcane bagasse. Any raw materials having 34% or higher α-cellulose contents were characterized as promising raw materials for industrial applications [32]. Lignin contents in P. hysterophorus were more than in wheat straw and sugarcane bagasse. ...
... Extractives were less in P. hysterophorus compared to those in wheat straw and sugarcane bagasse. As observed previously, the suitability of a biomass as a feedstock is proved to generate high glucose and ethanol yield, while it was investigated that hemicelluloses and lignin lowered the bioethanol production capability as a physical barrier, thus preventing the cellulose in the biomass to hydrolyze into monomer sugars [32][33][34]. P. hysterophorus had a significant quantity of cellulose which made it attractive as a raw material for ethanol production. The holocellulosic components of P. hysterophorus (64.2%) had an appreciable quantity compared to those of normally used feedstocks for bioethanol production such as sugarcane bagasse (74.2%) and wheat straw (55.5%) [35]. ...
The present study aimed at utilizing P. hysterophorus—a harmful weed that infested millions of hectares worldwide—for ethanol production. The organosolv pre-treatment of P. hysterophorus was carried out at 180 °C, maintaining ethanol to distilled water ratio of 3:1, solid to liquid ratio of 1:5, and reaction time of 60 min with 2% of H2SO4 (as catalyst). P. hysterophorus was subjected to FTIR, XRD, and FE-SEM analysis to observe the change after pre-treatment. P. hysterophorus produced total reducing sugars of 24.82±1.2g, ethano-organosolv lignin of 20.11±1.5g, and acid soluble lignin of 0.95±0.19g in hydrolysate after organosolv pre-treatment. Pre-treated substrate after enzymatic hydrolysis with Talaromyces stipitatus MTCC-12687 and Aspergillus niger NFCCI-4113 produced total reducing sugars of 32.34±1.2 and 32.85±1.2 g/100g of oven-dried material and total mass balance of 79.35 and 79.86 g/100 g of total solids respectively. The glucose and xylose recovery after enzymatic hydrolysis with T. stipitatus MTCC-12687and A. niger NFCCI-4113 were 94.3 and 94.8% and 63.3 and 63.4% respectively from the sample of P. hysterophorus coded as “H.” Detoxification of pre-treated hydrolysate was carried out using over-liming followed by activated charcoal treatment, and 86.3% and 94.2% reduction were found in furan and total phenols respectively with a loss of 4.5% of reducing sugar. Total reducing sugars after pre-treatment and enzymatic hydrolysis were mixed and subjected to co-fermentation using Saccharomyces cerevisiae MTCC-170 and Pichia stipitis NCIM-3497 in the ratio of 1:1 and produced 0.422g ethanol/g reducing sugars.
... Bioethanol, biohydrogen, biodiesel, and biogas are the main bioenergy produced from agro-residues. Processing of several agricultural wastes such as corn stalk, wheat straw, bagasse, and paddy straw to biogas can act as an alternative to solve the energy crisis (Tutt and Olt 2011;Saini et al. 2015;Das and Deka 2021;Mao et al. 2021). ...
The major global concern on energy is focused on conventional fossil resources. The burning of fossil fuels is an origin of greenhouse gas emissions resulting in the utmost threat to the environment and subsequently which leads to global climate changes. As far as sustainability is concerned, fuels and materials derived from organic or plant wastes overcome this downside establishing the solution to the fossil resource crisis. In this context, exploration of agricultural residue appears to be a suitable alternative of non-renewable resources to support the environmental feasibility and meet the high energy crisis. The use of agricultural waste as a feedstock for the biorefinery approach emerges to be an eco-friendly process for the production of biofuel and value-added chemicals, intensifying energy security. Therefore, a prospective choice of this renewable biomass for the synthesis of green fuel and other green biochemicals comes up with a favorable outcome in terms of cost-effectiveness and sustainability. Exploiting different agricultural biomass and exploring various biomass conversion techniques, biorefinery generates bioenergy in a strategic way which eventually fits in a circular bioeconomy. Sources and production of agricultural waste are critically explained in this paper, which provides a path for further value addition by various technologies. Biorefinery solutions, along with a life cycle assessment of agricultural waste biomass toward a wide array of value-added products aiding the bioeconomy, are summarized in this paper.
... Industrial hemp consists of three types of fibers in its stem: primary bast (outer long fibers), secondary bast fibers, and hemp hurds or shives (inner short fibers). The fibers have very high cellulose content with varying amounts of hemicellulose, lignin, and pectin as its major constituents (Tutt and Olt, 2011). The length of hemp fibers is 1-3 cm, and the bast contains 70.2-74.4% ...
Forensic laboratories are required to have analytical tools to confidently differentiate illegal substances such as marijuana from legal products (i.e., industrial hemp). The Achilles heel of industrial hemp is its association with marijuana. Industrial hemp from the Cannabis sativa L. plant is reported to be one of the strongest natural multipurpose fibers on earth. The Cannabis plant is a vigorous annual crop broadly separated into two classes: industrial hemp and marijuana. Up until the eighteenth century, hemp was one of the major fibers in the United States. The decline of its cultivation and applications is largely due to burgeoning manufacture of synthetic fibers. Traditional composite materials such as concrete, fiberglass insulation, and lumber are environmentally unfavorable. Industrial hemp exhibits environmental sustainability, low maintenance, and high local and national economic impacts. The 2018 Farm Bill made way for the legalization of hemp by categorizing it as an ordinary agricultural commodity. Unlike marijuana, hemp contains less than 0.3% of the cannabinoid, Δ9-tetrahydrocannabinol, the psychoactive compound which gives users psychotropic effects and confers illegality in some locations. On the other hand, industrial hemp contains cannabidiol found in the resinous flower of Cannabis and is purported to have multiple advantageous uses. There is a paucity of investigations of the identity, microbial diversity, and biochemical characterizations of industrial hemp. This review provides background on important topics regarding hemp and the quantification of total tetrahydrocannabinol in hemp products. It will also serve as an overview of emergent microbiological studies regarding hemp inflorescences. Further, we examine challenges in using forensic analytical methodologies tasked to distinguish legal fiber-type material from illegal drug-types.
... Processing of several agricultural wastes such as corn stalk, wheat straw, bagasse, paddy straw to biogas can act as an alternate to solve the energy crisis (Tutt andOlt 2011, Saini et al. 2015). ...
The over dependency on conventional fossil energy resources is the consequence of high energy demand and excessive consumption of petroleum fuel, which turns out to be a major concern of 21 st century. The burning of fossil fuel is an origin of greenhouse gas emission resulting in the utmost threat to environment subsequently which leads to global climate changes. As far as sustainability is concerned, fuels derived from organic or plant wastes overcome this downside and also are an established solution of the traditional oil resources depletion. In this context, exploration of agricultural residue appears to be a suitable alternate of non-renewable resources to support the environmental feasibility and meet the high energy crisis. Use of agricultural waste rather lignocellulosic biomass as a feedstock for biorefinery approach emerges to be an eco-friendly process for the production of biofuel and value-added chemicals intensifying the energy security. Therefore, a prospective choice of this renewable biomass for the synthesis of green fuel such as biobutanol, bioethanol keeps away food versus fuel dilemma and also comes up with favorable outcome in terms of cost effectiveness. Exploiting different agricultural biomass and exploring various biomass conversion techniques, biorefinery generates bioenergy in a strategic way which eventually fit in circular bioeconomy. The view of bioeconomy highlights the fruitful use of agricultural waste biomass in biorefinery acquiring such a system so that the by-products can be further utilized with low or no waste generation to maintain the sustainability and circularity of economy which are critically described.
... trees/shrubs, vs. reeds/grasses). Importantly for charcoal formation these two groups differ significantly in terms of their lignin content (trees/shrubs typically 25%, (Novaes et al., 2010); reeds/ grasses typically 9-19%, (Juneja et al., 2011;Kou et al., 2017;Novaes et al., 2010;Tutt and Olt, 2011;Wöhler-Geske et al., 2016)). By assigning the FTIR spectra into these groups we significantly increased the model performance for the two modern analogue matching models (i.e. from 38% and 50% to 67% and 75% respectively; Table 3). ...
Charcoal identification and the quantification of its abundance in sedimentary archives is commonly used to reconstruct fire frequency and the amounts of biomass burning. There are, however, limited metrics to measure past fire temperature and fuel type (i.e. the types of plants that comprise the fuel load), which are important for fully understanding the impact of past fire regimes. Here, we expand the modern reference dataset of charcoal spectra derived from micro-Fourier Transformed Infrared Spectroscopy (FTIR) and apply an analogue matching model to estimate the maximum pyrolysis temperature and the type of plant material burned. We generated laboratory-created reference charcoal from nine plant species that were heated to six temperature categories (100 °C increments between 200 °C–700 °C). The analogue matching approach used on the FTIR spectra of charcoal estimated the maximum pyrolysis temperatures with an accuracy of 57%, which improved to 93% when accuracy was considered ±100 °C. Model accuracy for the type of plant material burned was 38% at the species level, which increased to 67% when species were grouped into trait-based categories. Our results show that analogue matching is an effective approach for estimating pyrolysis temperature and the type of plant material burned, and we suggest that it can also be applied to charcoal found in palaeoecological records, improving our understanding of past fire regimes and fuel dynamics.
... Reference [49] reported that reed leaf contains a considerable percentage of lignin (8.74%), which has been shown to form chelates with different divalent ions such as Cd(II), Pb(II), Cu(II), Zn(II), and Ni(II) [50]. This is due to the pres-ence of functional groups (e.g., hydroxyl and carboxyl groups) in the structures of compounds attached to lignin (e.g., p-coumaryl, coniferyl, and sinapyl alcohol and some organic acids such as ferulic, p-coumaric, and p-hydroxybenzoic acid) [50,51]. ...
... In addition, the TOU model is numerically and computationally stable. The t 1/2 values for this system also show apparently irregular behavior; however, the origin of this variability is the same as that discussed for n and can be explained by the compositional heterogeneity of lignocellulosic materials such as reed leaves [49]. Evidently, the average t 1/2 value for this system is greater than that of the Pec-Ca and Xant-Al systems (see Table 5). ...
A novel stochastic model is proposed to characterize the adsorption kinetics of pollutants including dyes (direct red 80 and direct blue 1), fluoride ions, and cadmium ions removed by calcium pectinate (Pec-Ca), aluminum xanthanate (Xant-Al), and reed leaves, respectively. The model is based on a transformation over time following the Ornstein–Uhlenbeck stochastic process, which explicitly includes the uncertainty involved in the adsorption process. The model includes stochastic versions of the pseudo-first-order (PFO), pseudo-second-order (PSO), and pseudo-n-order (PNO) models. It also allows the estimation of the adsorption parameters, including the maximum removal capacity (qe), the adsorption rate constant (kn), the reaction pseudoorder (n), and the variability σ2. The model fitted produced R2 values similar to those of the nonstochastic versions of the PFO, PSO, and PNO models; however, the obtained values for each parameter indicate that the stochastic model better reproduces the experimental data. The qe values of the Pec-Ca-dye, Xant-Al-fluoride, and reed leaf-Cd+2 systems ranged from 2.0 to 9.7, 0.41 to 1.9, and 0.04 and 0.29 mg/g, respectively, whereas the values of kn ranged from 0.051 to 0.286, 0.743 to 75.73, and 0.756 to 8.861 (mg/g)1-n/min, respectively. These results suggest a variability in the parameters qe and kn inherent to the natures of the adsorbate and adsorbent. The obtained n values ranged from 1.13 to 2.02 for the Pec-Ca-dye system, 1.0–3.5 for the Xant-Al-fluoride system, and 1.8–3.8 for the reed leaf-Cd+2 system. These ranges indicate the flexibility of the stochastic model to obtain fractional n values, resulting in high R2 values. The variability in each system was evaluated based on σ2. The developed model is the first to describe pollutant removal kinetics based on a stochastic differential equation.
... Later, 1 mL of sulfuric acid (H 2 SO 4 ) (98% conc.) was added to bring down pH in the range of 4.5-5.0, because < 4 or > 6 pH can inhibit the enzymatic activity [45]. ...
The inadequate sanitation, global warming, and dwindling natural oil reserves pose significant threats to global sustainable growth. With this objective, biomass availability for bioenergy production could be ensured alternately by exploring non-conventional plant species and algae. This idea was examined by growing divergent plants and algae species separately in horizontal subsurface flow constructed wetlands and raceway ponds, later collected their biomass for bioethanol determination. Through this approach, sewage was fed to constructed wetlands and raceway ponds as influent and passed through these cultivated systems for wastewater treatment. Although all the four plant and algae species showed efficient results in sewage treatment, however, Ipomoea aquatica and Spirogyra were statistically superior to the others and produced the highest biomass yield of 4.5 and 4.1 kg m⁻², respectively. For bioethanol production, alkali–autohydrolysis combined pretreatment followed by enzymatic hydrolysis with two successive incubation periods (12 and 24 h) were employed. Results suggested that Spirogyra biomass rendered greater carbohydrate and ethanol concentration (3.7 and 1.9 mg L⁻¹, respectively) during 24 hours of incubation, whereas Oryza sativa acquired similar carbohydrate concentration as Spirogyra but slightly lower bioethanol yield. This study postulates, Spirogyra is promising for wastewater treatment coupled with bioethanol production.
Graphical abstract
Open raceway pond and constructed wetland coupled with wastewater treatment and bio-ethanol production
... The latter are imperforated elements with annular or helical thickenings of the secondary wall (Mauseth, 2004;Arruda and Melo de Pinna, 2010). The chemical composition of primary xylem has been described mainly in economically important herbaceous plants that do not have any secondary growth (Ekebafe et al., 2011;Cao et al., 2014), such as bamboo (Vena et al., 2010;Chang et al., 2013) and some forage species (Jung and Vogel, 1986;Cherney et al., 1988;Chaves et al., 2002;Tutt and Olt, 2011). ...
The xylem of Cactaceae is a complex system with different types of cells whose main function is to conduct and store water, mostly during the development of primary xylem, which has vessel elements and wide-band tracheids. The anatomy of primary xylem of Cactaceae has been widely studied, but little is known about its chemical composition. The aim of this study was to determine the structural chemical composition of the primary xylem of Cactaceae and to compare it with the anatomy in the group. Seeds from eight cacti species were used, representing the Pereskioideae, Opuntioideae, and Cactoideae subfamilies. Seeds were germinated and grown for 8 months. Subsequently, only the stem of the seedling was selected, dried, milled, and processed following the TAPPI T-222 om-02 norm; lignin was quantified using the Klason method and cellulose with the Kurshner–Höffer method. Using Fourier transform infrared spectroscopy, the percentage of syringyl and guaiacyl in lignin was calculated. Seedlings of each species were fixed, sectioned, and stained for their anatomical description and fluorescence microscopy analysis for the topochemistry of the primary xylem. The results showed that there were significant differences between species (p < 0.05), except in the hemicelluloses. Through a principal component analysis, it was found that the amount of extractive-free stem and hot water-soluble extractives were the variables that separated the species, followed by cellulose and hemicelluloses since the seedlings developed mainly parenchyma cells and the conductive tissue showed vessel elements and wide-band tracheids, both with annular and helical thickenings in secondary walls. The type of lignin with the highest percentage was guaiacyl-type, which is accumulated mainly in the vessels, providing rigidity. Whereas in the wide-band tracheids from metaxylem, syringyl lignin accumulated in the secondary walls S2 and S3, which permits an efficient flow of water and gives the plant the ability to endure difficult conditions during seedling development. Only one species can be considered to have paedomorphosis since the conductive elements had a similar chemistry in primary and secondary xylem.
