Displaying publications 81 - 100 of 220 in total

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  1. Lignocellulosic biomass supported metal nanoparticles for the catalytic reduction of organic pollutants
    Akhtar K, Ali F, Sohni S, Kamal T, Asiri AM, Bakhsh EM, et al.
    Environ Sci Pollut Res Int, 2020 Jan;27(1):823-836.
    PMID: 31811610 DOI: 10.1007/s11356-019-06908-y
    Lignocellulosic biomass waste is a cheap, eco-friendly, and sustainable raw material for a wide array of applications. In the present study, an easy, fast, and economically feasible route has been proposed for the preparation of different zero-valent metal nanoparticles (ZV-MNPs) based on Cu, Co, Ag, and Ni NPs using empty fruit bunch (EFB) biomass residue as support material. The catalytic efficiency of ZV-MNPs/EFB catalyst was investigated against five model pollutants, such as methyl orange (MO), congo red (CR), methylene blue (MB), acridine orange (AO), and 4-nitrophenol (4-NP) using NaBH4 as a source of hydrogen and electron. Comparative study revealed that among as-prepared ZV-MNPs/EFB catalysts, Cu-NPs immobilized onto EFB (Cu/EFB) exhibited maximum catalytic efficiency towards pollutant abasement. Degradation reactions were highly efficient, and were completed within a short time (4 min) in case of MO, CR, and MB, whilst AO and 4-NP were reduced in less than 15 min. Kinetic investigation revealed that the degradation rate of model pollutants accorded with pseudo-first order model. Furthermore, supported catalysts were easily recovered after the completion of experiment by simply pulling the catalyst from reaction system. Recyclability tests performed on Cu/EFB revealed that more than 97% of the reduction was achieved in case of MO dye for four successive cycles of reuse. The as-prepared heterostructure showed multifunctional properties, such as enhanced uptake of contaminants, high catalytic efficiency, and easy recovery, hence, offers great prospects in wastewater purification.
    Matched MeSH terms: Lignin/chemistry*
  2. Biphasic pretreatment excels over conventional sulfuric acid in pinewood biorefinery: An environmental analysis
    Khounani Z, Abdul Razak NN, Hosseinzadeh-Bandbafha H, Madadi M, Sun F, Mohammadi P, et al.
    Environ Res, 2024 May 01;248:118286.
    PMID: 38280524 DOI: 10.1016/j.envres.2024.118286
    This study assesses the environmental impact of pine chip-based biorefinery processes, focusing on bioethanol, xylonic acid, and lignin production. A cradle-to-gate Life Cycle Assessment (LCA) is employed, comparing a novel biphasic pretreatment method (p-toluenesulfonic acid (TsOH)/pentanol, Sc-1) with conventional sulfuric acid pretreatment (H2SO4, Sc-2). The analysis spans biomass handling, pretreatment, enzymatic hydrolysis, yeast fermentation, and distillation. Sc-1 yielded an environmental impact of 1.45E+01 kPt, predominantly affecting human health (96.55%), followed by ecosystems (3.07%) and resources (0.38%). Bioethanol, xylonic acid, and lignin contributed 32.61%, 29.28%, and 38.11% to the total environmental burdens, respectively. Sc-2 resulted in an environmental burden of 1.64E+01 kPt, with a primary impact on human health (96.56%) and smaller roles for ecosystems (3.07%) and resources (0.38%). Bioethanol, xylonic acid, and lignin contributed differently at 22.59%, 12.5%, and 64.91%, respectively. Electricity generation was predominant in both scenarios, accounting for 99.05% of the environmental impact, primarily driven by its extensive usage in biomass handling and pretreatment processes. Sc-1 demonstrated a 13.05% lower environmental impact than Sc-2 due to decreased electricity consumption and increased bioethanol and xylonic acid outputs. This study highlights the pivotal role of pretreatment methods in wood-based biorefineries and underscores the urgency of sustainable alternatives like TsOH/pentanol. Additionally, adopting greener electricity generation, advanced technologies, and process optimization are crucial for reducing the environmental footprint of waste-based biorefineries while preserving valuable bioproduct production.
    Matched MeSH terms: Lignin*
  3. Fractionation of oil palm empty fruit bunch by bisulfite pretreatment for the production of bioethanol and high value products
    Tan L, Wang M, Li X, Li H, Zhao J, Qu Y, et al.
    Bioresour Technol, 2016 Jan;200:572-8.
    PMID: 26539970 DOI: 10.1016/j.biortech.2015.10.079
    In this work, fractionation of empty fruit bunch (EFB) by bisulfite pretreatment was studied for the production of bioethanol and high value products to achieve biorefinery of EFB. EFB was fractionated to solid and liquor components by bisulfite process. The solid components were used for bioethanol production by quasi-simultaneous saccharification and fermentation. The liquor components were then converted to furfural by hydrolysis with sulfuric acid. Preliminary results showed that the concentration of furfural was highest at 18.8g/L with 0.75% sulfuric acid and reaction time of 25min. The conversion of xylose to furfural was 82.5%. Furthermore, we attempted to fractionate the liquor into hemicellulose sugars and lignin by different methods for producing potential chemicals, such as xylose, xylooligosaccharide, and lignosulfonate. Our research showed that the combination of bisulfite pretreatment and resin separation could effectively fractionate EFB components to produce bioethanol and other high value chemicals.
    Matched MeSH terms: Lignin
  4. Fulltext Evaluation of the Compatibility of Organosolv Lignin-Graphene Nanoplatelets with Photo-Curable Polyurethane in Stereolithography 3D Printing
    Ibrahim F, Mohan D, Sajab MS, Bakarudin SB, Kaco H
    Polymers (Basel), 2019 Sep 23;11(10).
    PMID: 31547544 DOI: 10.3390/polym11101544
    In this study, lignin has been extracted from oil palm empty fruit bunch (EFB) fibers via an organosolv process. The organosolv lignin obtained was defined by the presence of hydroxyl-containing molecules, such as guaiacyl and syringyl, and by the presence of phenolic molecules in lignin. Subsequently, the extracted organosolv lignin and graphene nanoplatelets (GNP) were utilized as filler and reinforcement in photo-curable polyurethane (PU), which is used in stereolithography 3D printing. The compatibility as well as the characteristic and structural changes of the composite were identified through the mechanical properties of the 3D-printed composites. Furthermore, the tensile strength of the composited lignin and graphene shows significant improvement as high as 27%. The hardness of the photo-curable PU composites measured by nanoindentation exhibited an enormous improvement for 0.6% of lignin-graphene at 92.49 MPa with 238% increment when compared with unmodified PU.
    Matched MeSH terms: Lignin
  5. A Comprehensive Review on Advanced Sustainable Woven Natural Fibre Polymer Composites
    Aisyah HA, Paridah MT, Sapuan SM, Ilyas RA, Khalina A, Nurazzi NM, et al.
    Polymers (Basel), 2021 Feb 02;13(3).
    PMID: 33540731 DOI: 10.3390/polym13030471
    Over the last decade, the progressive application of natural fibres in polymer composites has had a major effect in alleviating environmental impacts. Recently, there is a growing interest in the development of green materials in a woven form by utilising natural fibres from lignocellulosic materials for many applications such as structural, non-structural composites, household utilities, automobile parts, aerospace components, flooring, and ballistic materials. Woven materials are one of the most promising materials for substituting or hybridising with synthetic polymeric materials in the production of natural fibre polymer composites (NFPCs). These woven materials are flexible, able to be tailored to the specific needs and have better mechanical properties due to their weaving structures. Seeing that the potential advantages of woven materials in the fabrication of NFPC, this paper presents a detailed review of studies related to woven materials. A variety of factors that influence the properties of the resultant woven NFRC such as yarn characteristics, fabric properties as well as manufacturing parameters were discussed. Past and current research efforts on the development of woven NFPCs from various polymer matrices including polypropylene, polylactic acid, epoxy and polyester and the properties of the resultant composites were also compiled. Last but not least, the applications, challenges, and prospects in the field also were highlighted.
    Matched MeSH terms: Lignin
  6. Fulltext Optimization of cassava peel medium to an enriched animal feed by the white rot fungi Panus tigrinus M609RQY
    Tijani, I.D.R., Jamal, P., Alam, M.Z., Mirghani, M.E.S.
    International Food Research Journal, 2012;19(2):427-432.
    MyJurnal
    Media components such as wheat flour, MgSO4 and particle size were screened by Placket Burman design (PBD) while the operating range was fixed by one-factor-at-a-time method (OFAT), primarily for the enrichment of cassava peels as animal feed. Optimization of the selected media components was carried out using Face–Centered Central Composite Design (FCCCD) of the Response Surface Methodology (RSM) and the responses were measured in term of protein and lignin contents. Statistical analysis of the result showed that the quadratic term of wheat flour and the interaction between wheat flour and particle size were highly significant (P
    Matched MeSH terms: Lignin
  7. Fulltext Overliming effects on xylitol production from sago trunk hydrolysate
    Mohamad, N.L., Mustapa Kamal, S.M., Abdullah, A.G.L.
    Pertanika Journal of Science & Technology, 2011;19(2):415-422.
    MyJurnal
    Xylitol can be obtained from lignocellulosic materials containing xylose. However, the fraction of lignocellulose converted through dilute acid hydrolysis contains compounds that inhibit the fermenting micro-organisms. These inhibitors can be removed from the hydrolysate by detoxification method, prior to fermentation. This study describes effectiveness of overliming process to reduce the toxicity of hydrolysates generated from pre-treatment of sago trunk for xylitol production. The overliming pH 9 and 10 was studied and the results showed that pH 9 was showed 20% of sugar loss, which is low compared to pH 10. Candida tropicalis strain was used to evaluate the fermentability of overlimed sago trunk hydrolysate at pH 9 and non-overlimed hydrolysate medium. Meanwhile, Xylitol accumulation and productivity in the overlimed medium was found to be higher than the non-treated medium. The maximum production of xylitol was increased up to 74% and converted within 76 h. The results obtained improved the fermentation process when compared with the nontreated medium.
    Matched MeSH terms: Lignin
  8. Sustainable green pretreatment approach to biomass-to-energy conversion using natural hydro-low-transition-temperature mixtures
    Yiin CL, Quitain AT, Yusup S, Uemura Y, Sasaki M, Kida T
    Bioresour Technol, 2018 Aug;261:361-369.
    PMID: 29680702 DOI: 10.1016/j.biortech.2018.04.039
    Natural hydro-low-transition-temperature mixtures (NH-LTTMs) tend to be the most favorable next-generation green solvents for biomass pretreatment, as they are cheap and environmental friendly. The amount of water bound into the NH-LTTMs greatly affected their thermal stability, whereby the highest thermal stability was observed with the water content of 7.6 wt%. It is worth noting that, the highest molar transition energy of NH-LTTMs (47.57 kcal mol-1), which indicated the highest solubility, was optimized with the molar ratio of hydrogen bond donor (HBD)-hydrogen bond acceptor (HBA)-water (2:4:3) at a temperature of 60 °C. Hydrogen bonding networks of the NH-LTTMs, which led to the dissolution of biomass, were confirmed by the alteration in the peaks of the involved bonds and resonance signal to lower field through FTIR and 1H NMR spectra, respectively. The components evidenced in high-resolution mass spectra of extracted lignin showed its high potential to be valorized into useful fuels and chemicals.
    Matched MeSH terms: Lignin
  9. Fulltext Removal of shells in palm kernel cake via static cling and electrostatic separation
    Norhani Abdullah, Muhamad Akhmal Hakim Roslan, Shuhaimi Mustafa
    Journal of Biochemistry, Microbiology and Biotechnology, 2015;3(1):1-6.
    MyJurnal
    Palm kernel cake (PKC), a by-product of the palm oil industry is limited in its use as a feed ingredient for poultry due to its high fibre and lignin content. The presence of these antinutritive components is the result of shells contaminating the by-product. The nutritive value of PKC has to be improved in order to increase its inclusion rate in poultry diet. In this study, PKC was subjected to a separation method using static cling and electrostatic separation to removethe shells present in PKC. Response surface methodology based on Box-Behnken design was used to optimize the separation method with moisture content (8 to 18%), particle size distribution (0.5 to 2.5 mm) and feed rate (20 to 200 g/min) as the independent variables evaluated. According to the regression coefficients and significance of the quadratic polynomial model, the optimum separation parameters were as follows: 13% PKC moisture content;
    Matched MeSH terms: Lignin
  10. Cloning and analysis of the eg4cl1 gene and its promoter from oil palm (elaeis guineensis jacq.)
    Yusuf Chong Yu Lok, Idris Abu Seman, Nor Aini Ab Shukor, Mohd Norfaizull Mohd Nor, Mohd Puad Abdullah
    Sains Malaysiana, 2018;47:1709-1723.
    The empty fruit bunches of oil palm have been used as the raw material to produce biofuel. However, the lignin present
    in oil palm tissues hampers the enzymatic saccharification of lignocellulosic biomass and lower the yield of biofuel
    produced. Hence, various efforts were taken to identify the lignin biosynthetic genes in oil palm and to investigate
    their regulation at the molecular level. In this study, a lignin biosynthetic gene, Eg4CL1 and its promoter were isolated
    from the oil palm. Eg4CL1 contains the acyl-activating enzyme consensus motif and boxes I & II which are present in
    other 4CL homologs. Eg4CL1 was clustered together with known type I 4CL proteins involved in lignin biosynthesis in
    other plants. Gene expression analysis showed that Eg4CL1 was expressed abundantly in different organs of oil palm
    throughout the course of development, reflecting its involvement in lignin biosynthesis in different organs at all stages
    of growth. The presence of the lignification toolbox - AC elements in the 1.5 kb promoter of Eg4CL1 further suggests the
    potential role of the gene in lignin biosynthesis in oil palm. Together, these results suggested that Eg4CL1 is a potential
    candidate gene involved in lignin biosynthesis in oil palm.
    Matched MeSH terms: Lignin
  11. Parametric analysis of lignocellulosic ultrafiltration in lab scale cross flow module using pore blocking and artificial neural network model
    Yogarathinam LT, Velswamy K, Gangasalam A, Ismail AF, Goh PS, Subramaniam MN, et al.
    Chemosphere, 2022 Jan;286(Pt 3):131822.
    PMID: 34416593 DOI: 10.1016/j.chemosphere.2021.131822
    In this study, fouling mechanism and modelling analysis of synthetic lignocellulose biomass and agricultural palm oil effluent was studied using polyethersulfone (PES) ultrafiltration (UF) 10 kDa membrane. The impact of process variables (transmembrane pressure (TMP), pH and concentration of feed solution) on lignocellulosic flux was analysed using pore blocking model. The feasible approaches on utilising deep learning artificial neural network (ANN) to predict smaller flux datasets are studied. Among the input variables, pH of lignin feed solution has significant control towards flux and lignin rejection coefficient for both lignin and lignocellulosic solution. Alteration in the structure of lignin at different pH conditions contributed in the improvement of lignin rejection coefficient to 0.98 at the feed pH of 9. A maximum steady state flux of 52.03 L/m2h was observed at the lower lignin concentration (0.25 g/L), TMP of 200 kPa and feed pH of 3. At high TMP and concentration, lignin rejection decreased due to enhancement of feed concentration on membrane surface. The mechanistic model exhibited that cake layer phenomena was dominant in both lignin and lignocellulosic solution. The proposed ANN model showed good correlation (R2-1.00) with experimental non-linear flux dynamic data of both lignin and synthetic lignocellulosic solution. In ANN analysis, activation function, algorithm and neuron effect have significant effect in design of accurate model for prediction of small flux datasets. Aerobically-treated palm oil mill filtration analysis also showed that cake layer phenomenon was dominant. A water recovery of 82 % was achieved even at low TMP under short durations.
    Matched MeSH terms: Lignin
  12. The degradation of single-use plastics and commercially viable bioplastics in the environment: A review
    Idris SN, Amelia TSM, Bhubalan K, Lazim AMM, Zakwan NAMA, Jamaluddin MI, et al.
    Environ Res, 2023 Aug 15;231(Pt 1):115988.
    PMID: 37105296 DOI: 10.1016/j.envres.2023.115988
    Plastics have become an integral part of human life. Single-use plastics (SUPs) are disposable plastics designed to be used once then promptly discarded or recycled. This SUPs range from packaging and takeaway containers to disposable razors and hotel toiletries. Synthetic plastics, which are made of non-renewable petroleum and natural gas resources, require decades to perpetually disintegrate in nature thus contribute to plastic pollution worldwide, especially in marine environments. In response to these problems, bioplastics or bio-based and biodegradable polymers from renewable sources has been considered as an alternative. Understanding the mechanisms behind the degradation of conventional SUPs and biodegradability of their greener counterpart, bioplastics, is crucial for appropriate material selection in the future. This review aims to provide insights into the degradation or disintegration of conventional single-use plastics and the biodegradability of the different types of greener-counterparts, bioplastics, their mechanisms, and conditions. This review highlights on the biodegradation in the environments including composting systems. Here, the various types of alternative biodegradable polymers, such as bacterially biosynthesised bioplastics, natural fibre-reinforced plastics, starch-, cellulose-, lignin-, and soy-based polymers were explored. Review of past literature revealed that although bioplastics are relatively eco-friendly, their natural compositions and properties are inconsistent. Furthermore, the global plastic market for biodegradable plastics remains relatively small and require further research and commercialization efforts, especially considering the urgency of plastic and microplastic pollution as currently critical global issue. Biodegradable plastics have potential to replace conventional plastics as they show biodegradation ability under real environments, and thus intensive research on the various biodegradable plastics is needed to inform stakeholders and policy makers on the appropriate response to the gradually emerging biodegradable plastics.
    Matched MeSH terms: Lignin
  13. Fulltext Biotemplated synthesis of anatase titanium dioxide nanoparticles via lignocellulosic waste material
    Ramimoghadam D, Bagheri S, Abd Hamid SB
    Biomed Res Int, 2014;2014:205636.
    PMID: 25126547 DOI: 10.1155/2014/205636
    Anatase titanium dioxide nanoparticles (TiO2-NPs) were synthesized by sol-gel method using rice straw as a soft biotemplate. Rice straw, as a lignocellulosic waste material, is a biomass feedstock which is globally produced in high rate and could be utilized in an innovative approach to manufacture a value-added product. Rice straw as a reliable biotemplate has been used in the sol-gel method to synthesize ultrasmall sizes of TiO2-NPs with high potential application in photocatalysis. The physicochemical properties of titanium dioxide nanoparticles were investigated by a number of techniques such as X-ray diffraction analysis (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, thermogravimetric analysis (TGA), ultraviolet visible spectra (UV-Vis), and surface area and pore size analysis. All results consensually confirmed that particle sizes of synthesized titanium dioxide were template-dependent, representing decrease in the nanoparticles sizes with increase of biotemplate concentration. Titanium dioxide nanoparticles as small as 13.0 ± 3.3 nm were obtained under our experimental conditions. Additionally, surface area and porosity of synthesized TiO2-NPs have been enhanced by increasing rice straw amount which results in surface modification of nanoparticles and potential application in photocatalysis.
    Matched MeSH terms: Lignin/chemical synthesis; Lignin/chemistry
  14. Fulltext Conversion of lignocellulosic biomass to nanocellulose: structure and chemical process
    Lee HV, Hamid SB, Zain SK
    ScientificWorldJournal, 2014;2014:631013.
    PMID: 25247208 DOI: 10.1155/2014/631013
    Lignocellulosic biomass is a complex biopolymer that is primary composed of cellulose, hemicellulose, and lignin. The presence of cellulose in biomass is able to depolymerise into nanodimension biomaterial, with exceptional mechanical properties for biocomposites, pharmaceutical carriers, and electronic substrate's application. However, the entangled biomass ultrastructure consists of inherent properties, such as strong lignin layers, low cellulose accessibility to chemicals, and high cellulose crystallinity, which inhibit the digestibility of the biomass for cellulose extraction. This situation offers both challenges and promises for the biomass biorefinery development to utilize the cellulose from lignocellulosic biomass. Thus, multistep biorefinery processes are necessary to ensure the deconstruction of noncellulosic content in lignocellulosic biomass, while maintaining cellulose product for further hydrolysis into nanocellulose material. In this review, we discuss the molecular structure basis for biomass recalcitrance, reengineering process of lignocellulosic biomass into nanocellulose via chemical, and novel catalytic approaches. Furthermore, review on catalyst design to overcome key barriers regarding the natural resistance of biomass will be presented herein.
    Matched MeSH terms: Lignin/metabolism; Lignin/chemistry*
  15. Production of butanol by Clostridium saccharoperbutylacetonicum N1-4 from palm kernel cake in acetone-butanol-ethanol fermentation using an empirical model
    Shukor H, Al-Shorgani NK, Abdeshahian P, Hamid AA, Anuar N, Rahman NA, et al.
    Bioresour Technol, 2014 Oct;170:565-73.
    PMID: 25171212 DOI: 10.1016/j.biortech.2014.07.055
    Palm kernel cake (PKC) was used for biobutanol production by Clostridium saccharoperbutylacetonicum N1-4 in acetone-butanol-ethanol (ABE) fermentation. PKC was subjected to acid hydrolysis pretreatment and hydrolysates released were detoxified by XAD-4 resin. The effect of pH, temperature and inoculum size on butanol production was evaluated using an empirical model. Twenty ABE fermentations were run according to an experimental design. Experimental results revealed that XAD-4 resin removed 50% furfural and 77.42% hydroxymethyl furfural. The analysis of the empirical model showed that linear effect of inoculums size with quadratic effect of pH and inoculum size influenced butanol production at 99% probability level (P<0.01). The optimum conditions for butanol production were pH 6.28, temperature of 28°C and inoculum size of 15.9%. ABE fermentation was carried out under optimum conditions which 0.1g/L butanol was obtained. Butanol production was enhanced by diluting PKC hydrolysate up to 70% in which 3.59g/L butanol was produced.
    Matched MeSH terms: Lignin/analysis; Lignin/metabolism*
  16. Dissolution and delignification of bamboo biomass using amino acid-based ionic liquid
    Muhammad N, Man Z, Bustam MA, Mutalib MI, Wilfred CD, Rafiq S
    Appl Biochem Biotechnol, 2011 Oct;165(3-4):998-1009.
    PMID: 21720837 DOI: 10.1007/s12010-011-9315-y
    In the present work, the dissolution of bamboo biomass was tested using a number of ionic liquids synthesized in laboratory. It was observed that one of the synthesized amino acid-based ionic liquids, namely 1-ethyl-3-methylimidazolium glycinate, was capable of dissolving the biomass completely. The dissolved biomass was then regenerated using a reconstitute solvent (acetone/water) and was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The results were compared to preconditioned bamboo biomass. The regenerated biomass was found to have a more homogenous macrostructure, which indicates that the crystalline form and structure of its cellulose has changed from type Ι to type ΙΙ during the dissolution and regeneration process.
    Matched MeSH terms: Lignin/metabolism*; Lignin/chemistry
  17. Sequential ultrasonication and deep eutectic solvent pretreatment to remove lignin and recover xylose from oil palm fronds
    Ong VZ, Wu TY, Lee CBTL, Cheong NWR, Shak KPY
    Ultrason Sonochem, 2019 Nov;58:104598.
    PMID: 31450331 DOI: 10.1016/j.ultsonch.2019.05.015
    This study demonstrated the effect of two-pot sequential pretreatment, comprising of ultrasound assisted deep eutectic solvent (DES) with the aim to investigate the effects of ultrasound amplitude and duration in enhancing delignification. Oil palm fronds (OPF) were ultrasonicated in a water medium, followed by a pretreatment using DES (choline chloride:urea). Fourier transform infra-red spectroscopy, X-ray diffraction, field emission scanning electron microscope, Brunauer-Emmet-Teller and solubilised lignin concentration were conducted to confirm the effectiveness of ultrasound assisted DES on the pretreatment of OPF. The recommended ultrasound conditions were determined to be 70% amplitude and duration of 30 min, where the sequential DES pretreatment was able to reduce lignin content of OPF to 14.01%, while improving xylose recovery by 58%.
    Matched MeSH terms: Lignin/isolation & purification*; Lignin/chemistry*
  18. Fulltext i-Propylammonium Lead Chloride Based Perovskite Photocatalysts for Depolymerization of Lignin Under UV Light
    Kausar S, Altaf AA, Hamayun M, Rasool N, Hadait M, Akhtar A, et al.
    Molecules, 2020 Jul 31;25(15).
    PMID: 32752133 DOI: 10.3390/molecules25153520
    Lignin depolymerization for the purpose of synthesizing aromatic molecules is a growing focus of research to find alternative energy sources. In current studies, the photocatalytic depolymerization of lignin has been investigated by two new iso-propylamine-based lead chloride perovskite nanomaterials (SK9 and SK10), synthesized by the facile hydrothermal method. Characterization was done by Powder X-Ray Diffraction (PXRD), Scanning Electron Microscopy (SEM), UV-Visible (UV-Vis), Photoluminescence (PL), and Fourier-Transform Infrared (FTIR) Spectroscopy and was used for the photocatalytic depolymerization of lignin under UV light. Lignin depolymerization was monitored by taking absorption spectra and catalytic paths studied by applying kinetic models. The %depolymerization was calculated for factors such as catalyst dose variation, initial concentration of lignin, and varying temperatures. Pseudo-second order was the best suited kinetic model, exhibiting a mechanism for lignin depolymerization that was chemically rate controlled. The activation energy (Ea) for the depolymerization reaction was found to be 15 kJ/mol, which is remarkably less than conventional depolymerization of the lignin, i.e., 59.75 kJ/mol, exhibiting significant catalytic efficiencies of synthesized perovskites. Products of lignin depolymerization obtained after photocatalytic activity at room temperature (20 °C) and at 90 °C were characterized by GC-MS analysis, indicating an increase in catalytic lignin depolymerization structural subunits into small monomeric functionalities at higher temperatures. Specifically, 2-methoxy-4-methylphenol (39%), benzene (17%), phenol (10%) and catechol (7%) were detected by GC-MS analysis of lignin depolymerization products.
    Matched MeSH terms: Lignin/metabolism; Lignin/chemistry*
  19. Identification and expression profiling of genes governing lignin biosynthesis in Casuarina equisetifolia L
    Vikashini B, Shanthi A, Ghosh Dasgupta M
    Gene, 2018 Nov 15;676:37-46.
    PMID: 30201104 DOI: 10.1016/j.gene.2018.07.012
    Casuarina equisetifolia L. is an important multi-purpose, fast growing and widely planted tree species native to tropical and subtropical coastlines of Australia, Southeast Asia, Malaysia, Melanesia, Polynesia and New Caledonia. It is a nitrogen-fixing tree mainly used for charcoal making, construction poles, landscaping, timber, pulp, firewood, windbreaks, shelterbelts, soil erosion and sand dune stabilization. Casuarina wood is presently used for paper and pulp production. Raw material with reduced lignin is highly preferred to increase the pulp yield. Hence, understanding the molecular regulation of wood formation in this tree species is vital for selecting industrially suitable phenotypes for breeding programs. The lignin biosynthetic pathway has been extensively studied in tree species like Eucalypts, poplars, pines, Picea, Betula and Acacia sp. However, studies on wood formation at molecular level is presently lacking in casuarinas. Hence, in the present study, the transcriptome of the developing secondary tissues of 15 years old Casuarina equiseitfolia subsp. equisetifolia was sequenced, de novo assembled, annotated and mapped to functional pathways. Transcriptome sequencing generated a total of 26,985 transcripts mapped to 31 pathways. Mining of the annotated data identified nine genes involved in lignin biosynthesis pathway and relative expression of the transcripts in four tissues including scale-like leaves, needle-like brachlets, wood and root were documented. The expression of CeCCR1 and CeF5H were found to be significantly high in wood tissues, while maximum expression of CeHCT was documented in stem. Additionally, CeTUBA and CeH2A were identified as the most stable reference transcript for normalization of qRT-PCR data in C. equisetifolia. The present study is the first wood genomic resource in C. equisetifolia, which will be valuable for functional genomics research in this genus.
    Matched MeSH terms: Lignin/biosynthesis*; Lignin/genetics*
  20. Fulltext Expression profile of small RNAs in Acacia mangium secondary xylem tissue with contrasting lignin content - potential regulatory sequences in monolignol biosynthetic pathway
    Ong SS, Wickneswari R
    BMC Genomics, 2011 Nov 30;12 Suppl 3(Suppl 3):S13.
    PMID: 22369296 DOI: 10.1186/1471-2164-12-S3-S13
    BACKGROUND: Lignin, after cellulose, is the second most abundant biopolymer accounting for approximately 15-35% of the dry weight of wood. As an important component during wood formation, lignin is indispensable for plant structure and defense. However, it is an undesirable component in the pulp and paper industry. Removal of lignin from cellulose is costly and environmentally hazardous process. Tremendous efforts have been devoted to understand the role of enzymes and genes in controlling the amount and composition of lignin to be deposited in the cell wall. However, studies on the impact of downregulation and overexpression of monolignol biosynthesis genes in model species on lignin content, plant fitness and viability have been inconsistent. Recently, non-coding RNAs have been discovered to play an important role in regulating the entire monolignol biosynthesis pathway. As small RNAs have critical functions in various biological process during wood formation, small RNA profiling is an important tool for the identification of complete set of differentially expressed small RNAs between low lignin and high lignin secondary xylem.

    RESULTS: In line with this, we have generated two small RNAs libraries from samples with contrasting lignin content using Illumina GAII sequencer. About 10 million sequence reads were obtained in secondary xylem of Am48 with high lignin content (41%) and a corresponding 14 million sequence reads were obtained in secondary xylem of Am54 with low lignin content (21%). Our results suggested that A. mangium small RNAs are composed of a set of 12 highly conserved miRNAs families found in plant miRNAs database, 82 novel miRNAs and a large proportion of non-conserved small RNAs with low expression levels. The predicted target genes of those differentially expressed conserved and non-conserved miRNAs include transcription factors associated with regulation of the lignin biosynthetic pathway genes. Some of these small RNAs play an important role in epigenetic silencing. Differential expression of the small RNAs between secondary xylem tissues with contrasting lignin content suggests that a cascade of miRNAs play an interconnected role in regulating the lignin biosynthetic pathway in Acacia species.

    CONCLUSIONS: Our study critically demonstrated the roles of small RNAs during secondary wall formation. Comparison of the expression pattern of small RNAs between secondary xylem tissues with contrasting lignin content strongly indicated that small RNAs play a key regulatory role during lignin biosynthesis. Our analyses suggest an evolutionary mechanism for miRNA targets on the basis of the length of their 5' and 3' UTRs and their cellular roles. The results obtained can be used to better understand the roles of small RNAs during lignin biosynthesis and for the development of gene constructs for silencing of specific genes involved in monolignol biosynthesis with minimal effect on plant fitness and viability. For the first time, small RNAs were proven to play an important regulatory role during lignin biosynthesis in A. mangium.

    Matched MeSH terms: Lignin/biosynthesis*; Lignin/chemistry
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