Low Lignin Content Research Articles

Colonization and decomposition of litter produced by invasive Acacia dealbata and native tree species by stream microbial decomposers

Changes in forest composition and litter inputs to streams due to invasion by exotic tree species can affect the functioning of freshwater ecosystems. Acacia dealbata is an important invasive tree species in Mediterranean areas, and often replaces the native riparian vegetation. In this study, we assessed the chemical characteristics of three litter types produced by the invasive Ac. dealbata (leaflets, flowers and pods) and leaf litter produced by two native tree species with contrasting litter characteristics (Quercus robur and Alnus glutinosa). We then assessed litter decomposition and associated microbial activity (i.e., overall microbial metabolism as respiration, fungal growth as biomass accumulation, and reproduction by aquatic hyphomycetes as conidial production), and the aquatic hyphomycetes community structure, in laboratory microcosms. In general, Ac. dealbata pods supported lower microbial activity and decomposed slower than all other litter types, due to their low nutrient concentrations and high carbon:nutrients molar ratio. Alnus glutinosa leaf litter supported high microbial activity and decomposed fast, due to its relatively high nutrient concentrations, low carbon:nutrients molar ratios and low lignin concentration. Acacia dealbata leaflets and flowers and Q. robur leaf litter generally had similar microbial activity and decomposition rates, intermediate between those of Ac. dealbata pods and Al. glutinosa leaf litter, likely due to trade-offs between nutrient concentrations and concentrations of structural and secondary compound among litter types. Aquatic hyphomycetes community structure also differed among litter types. For instance, Ac. dealbata pods had the lowest species richness per sampling date, but due to high dissimilarity among replicates, total species richness over the incubation period was comparable to that of other litter types. The invasion of native riparian forests by Ac. dealbata can affect the quality of litter inputs into streams, potentially affecting the community structure and activity of microbial decomposers, thus altering the functioning of stream ecosystems.

Slow pyrolysis of flax straw biomass produced in Kazakhstan: Characterization of enhanced tar and high-quality biochar

In the present study, local flax straw waste biomass samples were studied for their physical and chemical characteristics using a thermogravimetric analyzer (TGA) and thermal properties. Thermochemical conversion of the flax straw samples was performed in an electrically heated horizontal tube furnace from 400 to 600℃. Thermal analysis of the flax straw biomass showed higher calorific value of 18.2 MJ/kg, cellulose (27.4 wt%) and hemicellulose (24.8 wt%) content and lower lignin content (21.2 wt%). Mass balance of pyrolysis products showed 40.3% for bio-oil fraction at temperature of 500 ℃, which resulted in a notable reduction in the biochar yield by 34.6% compared to biochar yield at temperature of 400 ℃. Pyrolysis of flax straw samples further shows a notable reduction in moisture, ash and fixed carbon by 4.4%, 2.9% and 11.4%, respectively. In addition, it was noted that the tar obtained from flax straw is mostly composed of phenolic components, while XRD analysis confirms the degradation of cellulose in biochar fraction. Due to the higher de-volatilization behavior, calorific value, cellulose and hemicellulose content, also lower lignin and ash content, flax straw biomass can be used as a promising feedstock for bioenergy production.

Mercury stress tolerance in wheat and maize is achieved by lignin accumulation controlled by nitric oxide

Nitric oxide (NO) is an important phytohormone for plant adaptation to mercury (Hg) stress. The effect of Hg on lignin synthesis, NO production in leaf, sheath and root and their relationship were investigated in two members of the grass family - wheat and maize. Hg stress decreased growth and lignin contents, significantly affected phenylpropanoid and monolignol pathways (PAL, phenylalanine ammonia-lyase; 4-coumarate: CoA ligase, 4CL; cinnamyl alcohol dehydrogenase, CAD), with maize identified to be more sensitive to Hg stress than wheat. Among the tissue types, sheath encountered severe damage compared to leaves and roots. Hg translocation in maize was about twice that in wheat. Interestingly, total NO produced under Hg stress was significantly decreased compared to control, with maximum reduction of 43.4% and 42.9% in wheat and maize sheath, respectively. Regression analysis between lignin and NO contents or the activities of three enzymes including CAD, 4CL and PAL displayed the importance of NO contents, CAD, 4CL and PAL for lignin synthesis. Further, the gene expression profiles encoding CAD, 4CL and PAL provided support for the damaging effect of Hg on wheat sheath, and maize shoot. To validate NO potential to mitigate Hg toxicity in maize and wheat, NO donor and NO synthase inhibitor were supplemented along with Hg. The resulting phenotype, histochemical analysis and lignin contents showed that NO mitigated Hg toxicity by improving growth and lignin synthesis and accumulation. In summary, Hg sensitivity was higher in maize seedlings compared to wheat, which was associated with the lower lignin contents and reduced NO contents. External supplementation of NO is proposed as a sustainable approach to mitigate Hg toxicity in maize and wheat.

Tailored production of lignin-containing cellulose nanofibrils from sugarcane bagasse pretreated by acid-catalyzed alcohol solutions

In this study, sugarcane bagasse was pretreated with acid-catalyzed alcohols, i.e., ethanol (AE), ethylene glycol (AEG) and glycerol (AG) to prepare pulps for producing lignin-containing cellulose nanofibrils (LCNF) with tailored properties, such as hydrophilicity/hydrophobicity and dispersion stability. The results showed that AG-LCNF had the highest lignin content of 16% but relatively low hydrophobicity while AE-LCNF had a low lignin content of 11% but the highest hydrophobicity. LCNF diameter distribution, crystallinity, zeta potentials and thermal stability were also determined to understand the effects of pretreatment solvent. NMR analyses revealed that alcohols modified lignin at α-position by etherification and γ-position by esterification of aliphatic chains, subsequently affecting lignin oxidation by TEMPO in the LCNF production processes, LCNF properties and LCNF dispersion in different solvents. This study provided fundamental information in the design and tailored production of LCNF for various applications, such as manufacturing polymer composites and Pickering emulsions.

Fungal communities represent the majority of root-specific transcripts in the transcriptomes of Agave plants grown in semiarid regions.

Agave plants present drought resistance mechanisms, commercial applications, and potential for bioenergy production. Currently, Agave species are used to produce alcoholic beverages and sisal fibers in semi-arid regions, mainly in Mexico and Brazil. Because of their high productivities, low lignin content, and high shoot-to-root ratio, agaves show potential as biomass feedstock to bioenergy production in marginal areas. Plants host many microorganisms and understanding their metabolism can inform biotechnological purposes. Here, we identify and characterize fungal transcripts found in three fiber-producing agave cultivars (Agave fourcroydes, A. sisalana, and hybrid 11648). We used leaf, stem, and root samples collected from the agave germplasm bank located in the state of Paraiba, in the Brazilian semiarid region, which has faced irregular precipitation periods. We used data from a de novo assembled transcriptome assembly (all tissues together). Regardless of the cultivar, around 10% of the transcripts mapped to fungi. Surprisingly, most root-specific transcripts were fungal (58%); of these around 64% were identified as Ascomycota and 28% as Basidiomycota in the three communities. Transcripts that code for heat shock proteins (HSPs) and enzymes involved in transport across the membrane in Ascomycota and Basidiomycota, abounded in libraries generated from the three cultivars. Indeed, among the most expressed transcripts, many were annotated as HSPs, which appear involved in abiotic stress resistance. Most HSPs expressed by Ascomycota are small HSPs, highly related to dealing with temperature stresses. Also, some KEGG pathways suggest interaction with the roots, related to transport to outside the cell, such as exosome (present in the three Ascomycota communities) and membrane trafficking, which were further investigated. We also found chitinases among secreted CAZymes, that can be related to pathogen control. We anticipate that our results can provide a starting point to the study of the potential uses of agaves’ fungi as biotechnological tools.

Effects of localized environment on the eucalypt clones quality aiming kraft pulp production

Abstract Wood is the most expensive fraction in the pulp production costs. Therefore, strategies for increasing wood quality such as faster growth, higher wood basic density and lower lignin content are drivers to pulp mills. The cultivation site as well as the eucalypt clones influence the wood quality, which, in turn, affects the pulp production performance. Thus, this work aims to evaluate the effect of the site on the wood quality for the pulp production. Three eucalypt clones from five different sites in Brazil were used in this study. These samples were selected aiming to represent a gradient of environmental stress. It was possible to observe a reduction in the content of extractives and lignin and an increase in the content of glucans in the sites with less environmental stress, reflecting in the production of pulp with less effective alkali demanded (reduction of 13.5 %) and an increase of 10.5 % in the kraft pulp screened yield. MAIP values of 22.7 ton/ha/year were obtained in the sites with less environmental stress, presenting a lower specific wood consumption. Through the production indicators, it was observed that the C1 clone is more adaptable to the regions of greater environmental stress than the other clones analyzed.

Rheology and Filtration Properties of Bentonite–Water Suspensions as Influenced by Lignocellulosic Nanomaterials and Water-Soluble Biopolymer Additives

Stability, structural morphology, and rheological and filtration properties of bentonite (BT)–water suspensions as influenced by the addition of lignocellulosic nanomaterials, including bleached nanofibrillated cellulose (NFC) and lignin-containing NFC (LNFC), and water-soluble polymers (WSPs) were investigated in this work. The performance of the formed fluids varied with the distinct fiber morphology and/or chemical composition of the NFC and LNFC. The NFC helped bridge BT particles for enhanced rheological performance but adversely affected filtration properties by forming thicker filter cakes. Reground NFC led to improved rheological properties owing to more individualized fibers with an enlarged surface area, but its effect on fluid loss was insignificant. LNFC enhanced viscosity, yield stress, and gelation properties of the fluid with effectiveness varying with the actual lignin content in the system. Enhanced filtration performance was seen with the presence of lignin in LNFC ascribed by its hydrophobic nature as well as the formation of more compact filter cakes. The applied biopolymers depicted better compatibility with smaller cellulosic fibril dimensions and lower lignin content. Thus, LNFC with moderate amounts of lignin in combination with biopolymer additives can help achieve much-improved rheological and filtration performance of BT-based fluids with lower cost and more environmental friendliness.

Novel millet husk crop-residue based thermoplastic composites: Waste to value creation

The objective of the current research endeavor is to explore the potential of novel natural lignocellulosic crop-residue fibers (husk) extracted from the finger millet (Eleusine coracana) and barnyard millet (Echinochloa frumentaceae). The extracted finger millet husk (FMH) and barnyard millet husk (BMH) were characterized for their physical (extractive and density), chemical (X-ray photo spectroscopy and Fourier transform infrared spectroscopy), thermal (Thermo-gravimetric analysis), and morphological (X-ray diffraction and Scanning electron microscopy) behavior. The major objective was to explore their potential in the development of thermoplastic composites. Thermal kinetics of the fibers were studied with Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) models. After fiber characterization, the composites were developed using injection molding process and characterized for mechanical, thermal, and morphological behavior. In the end, the flammability properties of the developed composites were investigated with Thermo-gravimetric analysis, UL-94 Horizontal burning, and Limiting Oxygen Index testing. Chemical constituent analysis reveals higher cellulosic and lower lignin content of FMH (cellulose; 38.01% and lignin; 16.25%) than BMH (cellulose; 34.5% and lignin; 21.31%). Thermal kinetics shows higher activation energy (Ea) for BMH (207.17 kJ/mol) than FMH (129.82 kJ/mol) as per the FWO model. BMH reinforced composites offer higher thermal stability and flame resistance than FMH reinforced composites, while FMH reinforced composites show higher mechanical properties than BMH reinforced composites. Overall, both husks show the potential to be used in developing thermoplastic composites.

PHENOTYPIC AND GENETIC VARIABILITY INDUCED BY GAMMA IRRADIATION IN WILMAN LOVEGRASS Eragrostis superba (PEYR.)

Wilman lovegrass [Eragrostis superba (Peyr.)] is a species used worldwide to revegetate rangelands; however, it has a low nutritional quality and a poor tolerance to water stress; thus, it can be a candidate for plant breeding. In this study, the morphological, nutritional, stomatal and molecular diversity induced y gamma irradiation was evaluated in Wilman lovegrass. Seed of the common variety was exposed to gamma radiation at doses of 100, 200, 300, 450, 600, 900, 1400 and 2000 Gy; in addition, non-irradiated seed was used as a control. Seed of the different treatments was used to produce plants in a greenhouse, which were evaluated through traits related to forage quality and water stress tolerance. The first generation of plants derived from mutagenic treatments (M1) was selected based on agronomic traits. The selected promissory mutants were then nutritionally, stomatally and molecularly characterized. All the possible selected mutants presented lower lignin content (P ≤ 0.01) compared to the common variety. The 200-3 and 200-7 promissory mutants showed higher protein content (P ≤ 0.01) at maturity stage. Also, significant differences (P ≤ 0.01) were found between putative mutants and control plants in stomatal density and stomatal area. The molecular analysis revealed significant differences (P ≤ 0.05) between the control genotype and the promissory mutants 200-3, 600-3, and 600-6, which presented genetic distances of 0.41, 0.42 and 0.35 (Dice’s coefficient) in relation to the control genotype, respectively. The phenotypic and genetic variability induced by gamma irradiation allowed to select the first generation of putative mutants with outstanding agronomic traits, nutritional value and stomatal characteristics.

ENVIRONMENTALLY FRIENDLY BLEACHING OF DISSOLVING CHEMICAL SULPHITE WOOD PULP AND CHARACTERIZATION OF WASTE WATER

The aim of the work is the environmental assessment for bleaching and alkali treatment of dissolving chemical pulp. Samples of the original unbleached pulp: industrial hard bisulfite pulp with a high mass fraction of lignin, traditionally used for the production of paper, and soft sulfite pulp with a low content of lignin, usually used to produce dissolving chemical pulp. In order to reduce the environmental impact, bleaching and alkali treatment were carried out according to the original technologies developed by the authors: bisulfite pulp - according to the ECF technology using two oxidizing bleaching reagents by scheme Pa-E-Ch1-HE-Ch2-A; sulfite pulp - according to the TCF-technology using one oxidizing bleaching agent by scheme Pa-E-HE-P-A in just 4 stages. Produced samples of pulp according to the standardized quality indicators, meet the requirements of the norms for wood sulphite pulp CA grade P (for nitration). The environmental characteristics of wastewater from bleaching and alkali treatment of both samples using the developed ECF and TCF technologies after biological treatment in terms of the main indicators (COD, BOD, AOX) comply with EU standards.

Leaf Litter Decomposition and Nutrient Release Dynamics of Flemingia semialata Roxb. - A Potential Woody Perennial Species for Mountain Agroforestry

ABSTRACT Leaf litter decomposition and nutrient release dynamics of Flemingia semialata Roxb. were studied from May 2016 to April 2017 using the litter bag technique. The study on litter dynamics is needed to assess the nutrient release pattern before introduction in degraded or marginal lands or agroforestry systems for soil nutrient management practices in hilly northeast states of India. The initial N concentration, lignin content, and lignin/N ratio of leaf litter had significant positive correlations with decay coefficients. The annual decay rate constant (k) for dry matter was 0.01 day−1 (3.65 year−1) with t50 and t99 values of 96.43 and 695.73 days, respectively, indicating faster leaf litter decomposition. Initial C (51%), N (2.38%), and low lignin concentrations with low C/N (21.53) and lignin/N (4.05) ratios could be important factors in faster mass loss from the litter samples. The P mineralization k P (2.19) rate was higher than k N (0.73), indicating the slower release rate of N. The weight loss during decomposition was positively correlated with rainfall (r = 0.42) and temperature (r = 0.39). The study suggests that F. semialata leaf litter could be useful for regulating soil nutrient pool through faster litter turnover and can therefore be exploited as plantation and/or agroforestry species for soil and water conservation in degraded slopy terrain of the region.

Production and characterization of Imperata cylindrica paper using potassium hydroxide as pulping agent

Abstract. Madung Z, Soloi S, Majid MHA, Sarjadi MS. 2022. Production and characterization of Imperata cylindrica paper using potassium hydroxide as pulping agent. Biodiversitas 23: 1490-1494. Non-woody plants have become an alternative fiber in paper production as woods, the primary sources of papers have become limited due to increasing demand of paper year by year. Imperata cylindrica or cogon grass as the source of fiber for the pulp and paper industry in replacing the wood fiber because it has high cellulose and low lignin content. In this study, cogon grasses were treated with various concentrations of potassium hydroxide, KOH (5%, 8%, 10% and 12%). The effects of alkali treatment on the properties of the papers were investigated in the present study. Scanning Electron Microscope (SEM) image of the paper sheet indicates that the amount of cellulose fiber and other materials were lessening toward a higher concentration of KOH treatment. This explained that most of the lignin was entirely removed and some cellulose probably degraded at higher KOH concentrations. Fourier Transform Infa-Red (FTIR) analysis showed that the peaks at range 1650 cm-1-1630 cm-1 attributed to the presence of v(C=C) aromatic ring of lignin disappeared at 10% and 12% of KOH. The mechanical strength of the papers decreased with an increasing concentration of KOH, while 5% of KOH produced the highest value of tensile strength.

A Comparative Investigation on Structural and Chemical Differences between the Pith and Rind of Sunflower Stalk and Their Influences on Nanofibrillation Efficiency

The structure and chemical composition of cell walls play a vital role in the bioconversion and utilization of plants. In the present study, the cell wall structure and chemical composition of pith and rind from sunflower stalks were compared and correlated to their nanofibrillation efficiency with ultrasonic treatment. Mild chemical pretreatment using 1% or 4% NaOH without any bleaching process were applied prior to ultrasonication nanofibrillation. Significant structural and chemical differences were demonstrated between the pith and rind, with the former exhibiting a much lower lignin and hemicellulose contents, higher pectin, much looser cell structure and higher cell wall porosity than the latter. Alkaline treatment alone was sufficient to eliminate most of the hemicellulose and pectin from stalk pith, whereas only partial removal of hemicellulose and lignin was achieved for the woody rind part. After 30 min of ultrasonic treatment, the stalk pith exhibited fully defibrillated fibrils with a continuous and entangled micro/nanofibrillated network, whereas numerous micron-sized fiber and fragments remained for the rind. The results indicated that stalk pith is less recalcitrant and easier to be fibrillated with ultrasonication than rind, which must be correlated to their distinct differences in both structure and chemical composition.

Initial wood trait variation overwhelms endophyte community effects for explaining decay trajectories

AbstractMicrobial organisms, environmental conditions and their interactions govern many ecosystem processes. Recent studies have highlighted the importance of priority effects, that is, the identity of potential decomposers present early in community assembly, in determining resulting decay rates especially for wood. In diverse forests, available woody substrates differ chemically and structurally with implications for their role as both habitats and resources for microbes. Both wood traits and microbial communities at the start of the decay process affect subsequent decay rates, but the relative magnitude of effects is not known. In this work, we sought to ask a simple question: what are the relative effects of microbial communities and wood traits?We characterized fungal and oomycete endophytes with amplicon sequencing from stems of 22 woody species growing in woodlands near Richmond, NSW, Australia, and measured 11 traits to capture variation in the physical and chemical wood substrates. To evaluate the consequence of endophyte diversity and wood traits on the trajectory of decay, stem samples were sequentially harvested over 5 years to quantify the decay rate, its consistency and how it varies through time.We did not find evidence to support particular initial endophyte compositions leading to faster decay. Instead, initial wood attributes were much more powerful in explaining decay trajectories with smaller, less dense stems with high water, low N and low lignin concentrations decomposing consistently faster.These data show that initial wood traits have long‐lasting consequences on decay unlike natural variation in endophyte communities, supporting the idea that community member functions are highly redundant. Wood substrate‐driven environmental filtering, rather than endophyte‐driven priority effects, had a stronger effect on decay when real‐world levels of diversity in wood traits were considered.Read the freePlain Language Summaryfor this article on the Journal blog.

Biomass yield and quality of the Miscanthus × giganteus in northern China

AbstractMiscanthus × giganteus has attracted much attention and occupied a significant niche as a bioenergy crop to meet the world's energy demand and in the fight against climate change. In this study, a field experiment was conducted to evaluate the yield and biomass characteristics of M. × giganteus over a period of three years from 2013 to 2015 in Beijing, China. M. × giganteus plants showed higher tiller density and litter leaf weight in the third year, whereas no significant difference in plant height was observed among the years. In contrast, a larger number of nodes per plant were recorded in the first year. Biomass yield potential was the highest in the third year (42.3 t ha−1). In addition, plant height (r = .594, p = .042), tiller density (r = .854, p < .01), and number of nodes per plant (r = ‐.589, p = .044) were significantly correlated with biomass yield. Contents of cellulose and lignin were higher in stems, while that of hemicellulose and ash were higher in leaves. M. × giganteus biomass may be used for cellulosic ethanol conversion due to high cellulose and hemicellulose contents and low lignin content and for direct combustion and co‐combustion due to high calorific value (18.5 MJ kg−1). To conclude, our findings indicate that M. × giganteus can be cultivated in northern China as an excellent herbaceous bioenergy crop. Rational utilization of the agronomic characteristics would be helpful to screening and breeding bioenergy grass for promoting bioenergy production in China.

Biohydrogen production by deep eutectic solvent delignification-driven enzymatic hydrolysis and photo-fermentation: Effect of liquid–solid ratio

Deep eutectic solvent (DES), a new green solvent, was used to pretreat corncob to enhance biohydrogen production. As a result of the pretreatment, lignin was effectively removed, and the maximum delignification efficiency of 83.12% was achieved. Moreover, the contents of cellulose in the pretreated corncob significantly increased. DES pretreatment effect improved with increasing liquid–solid ratio. The pretreated corncob’s enzymatic saccharification activity and hydrogen production were promoted due to the lower content of lignin. The best result was observed at a ratio of 25:1 (DES:corncob, g/g), in which the reducing sugar concentration (53.91 g/L) and the hydrogen yield (151 mL/g) was 6.8 and 3.1 times than that of untreated corncob, respectively. In addition, the lag time of hydrogen production was obviously shortened to 16.53 h due to the utilization of abundant available fermentable sugars, which accelerated hydrogen production.

Revealing the mechanism of lignin re-polymerization inhibitor in acidic pretreatment and its impact on enzymatic hydrolysis

Phenolic additives, including 2-naphthol, 2-naphthol-7-sulfonate, and resorcinol were evaluated for their impact on the lignin re-polymerization and subsequent hydrolysis of bamboo residues. Low surface lignin concentration (65.68%) of the substrate and high Tg value (185 °C) of lignin was observed for 2-naphthol-7-sulfonate assisted pretreatment, leading to the most significant increase (14%) in enzymatic hydrolysis efficiency of pretreated bamboo residues. Meanwhile, physicochemical properties of lignin revealed that the introduced sulfonic acid groups increased the surface charge, decreased the molecular weight, promoted the cleavage of β-O-4 linkages, and prevented the re-condensation of lignin. Even though resorcinol-assisted pretreatment, by contrast, was found to be an inhibitor for enzymatic hydrolysis. NMR analysis of modified lignin showed that resorcinol led to a higher amount of non-condensed phenolic OH groups and promoted the cleavage of β-O-4 linkages, acting as an inhibitor in lignin re-polymerization during the dilute acidic pretreatment. In short, the above findings present a detailed view of suppressing lignin re-polymerization for boosting the utilization of bioresources with acidic pretreatment.

Development and Characterization of Plantain (Musa paradisiaca) Flour-Based Biopolymer Films Reinforced with Plantain Fibers.

Agroindustrial wastes are a cheap and abundant source of natural fibers and macromolecules that can be used in the manufacturing of biocomposites. This study presents the development and thermo-mechanical characterization of a bio-composite film (TPF/PF), made of thermoplastic banana flour (TPF) matrix and plantain fibers (PF). Fabricated materials were characterized by physical analysis, chemical composition, Fourier-transformed spectroscopy (FTIR), thermal analysis (TGA), mechanical analysis, and scanning electronic microscopy (SEM). The physical analysis showed that TPF and PF have a low density and high affinity to water resulting in a lightweight, renewable, and biodegradable TPF/PF composite. The chemical composition and spectra analysis of the fiber showed that PF is a potential candidate for reinforcing composites due to its high α-cellulose and low lignin content. The thermal analysis determined that TPF degrades at a lower temperature than PF, therefore the matrix sets the processing temperature for TPF/PF composite films. The mechanical test showed an improvement in the tensile properties of the composite in comparison to neat TPF. Tensile strength and Young’s modulus were improved by 345% and 1196%, respectively, when PF fibers was used. Good bonding and mechanical interlocking of PF to the TPF were identified by SEM. Therefore, potential biocomposites can be developed using natural fibers and thermoplastic starches obtained from plantain agroindustrial wastes.

Cellulose and lignin profiling in seven, economically important bamboo species of India by anatomical, biochemical, FTIR spectroscopy and thermogravimetric analysis

Bamboos, a group of non-timber grasses, offers a great promise for the ligno-cellulosic biomass industry due to their very fast growth resulting rapid accumulation of lignocellulose biomasses, high fibre contents, low maintenance cost and existence of a diverse genetic pool. Despite, not voluminous and significant studies aimed to investigate the anatomy and biochemistry related to the cellulose and lignin synthesis in bamboos. Particularly, there remains a big knowledge gap on the variations of cellulose and lignin contents that exists at the germplasm level. Therefore, this study aimed to analyse chemical composition of ligno-cellulosic biomasses obtained from internode tissues of seven, abundantly available bamboo species of India (Bambusa balcooa, B. tulda, B. bambos, B. nutans, B. striata, Dendrocalamus giganteus, and D. strictus) by performing Attenuated Total Reflection-Fourier Transform Infrared (ATR-FTIR) Spectroscopy and Thermogravimetric analysis (TGA). Four anatomical parameters were used to predict ‘superior’ bamboo species/genotypes with respect to high cellulose vs. low lignin content. Particularly integrated density (ID) of Fast green and Phloroglucinol stains were correlated to the biochemical estimates of cellulose and lignin conducted on 63 samples. Hence the study concludes that stain ID can be used for quick screening of bamboo germplasms having desired ligno-cellulose contents. On the basis of multiple parameters analysed, B. bambos emerged as a reference bamboo for future ligno-cellulose research.

Physical and Chemical Properties of Acacia mangium Lignin Isolated from Pulp Mill Byproduct for Potential Application in Wood Composites.

The efficient isolation process and understanding of lignin properties are essential to determine key features and insights for more effective lignin valorization as a renewable feedstock for the production of bio-based chemicals including wood adhesives. This study successfully used dilute acid precipitation to recover lignin from black liquor (BL) through a single-step and ethanol-fractionated-step, with a lignin recovery of ~35% and ~16%, respectively. The physical characteristics of lignin, i.e., its morphological structure, were evaluated by scanning electron microscopy (SEM). The chemical properties of the isolated lignin were characterized using comprehensive analytical techniques such as chemical composition, solubility test, morphological structure, Fourier-transform infrared spectroscopy (FTIR), 1H and 13C Nuclear Magnetic Resonance (NMR), elucidation structure by pyrolysis-gas chromatography-mass spectroscopy (Py-GCMS), and gel permeation chromatography (GPC). The fingerprint analysis by FTIR detected the unique peaks corresponding to lignin, such as C=C and C-O in aromatic rings, but no significant differences in the fingerprint result between both lignin. The 1H and 13C NMR showed unique signals related to functional groups in lignin molecules such as methoxy, aromatic protons, aldehyde, and carboxylic acid. The lower insoluble acid content of lignin derived from fractionated-step (69.94%) than single-step (77.45%) correlated to lignin yield, total phenolic content, solubility, thermal stability, and molecular distribution. It contradicted the syringyl/guaiacyl (S/G) units’ ratio where ethanol fractionation slightly increased syringyl unit content, increasing the S/G ratio. Hence, the fractionation step affected more rupture and pores on the lignin morphological surface than the ethanol-fractionated step. The interrelationships between these chemical and physicochemical as well as different isolation methods were investigated. The results obtained could enhance the wider industrial application of lignin in manufacturing wood-based composites with improved properties and lower environmental impact.