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1.
Molecules ; 28(5)2023 Feb 22.
Artículo en Inglés | MEDLINE | ID: mdl-36903307

RESUMEN

Cellulosic ethanol is regarded as a perfect additive for petrol fuels for global carbon neutralization. As bioethanol conversion requires strong biomass pretreatment and overpriced enzymatic hydrolysis, it is increasingly considered in the exploration of biomass processes with fewer chemicals for cost-effective biofuels and value-added bioproducts. In this study, we performed optimal liquid-hot-water pretreatment (190 °C for 10 min) co-supplied with 4% FeCl3 to achieve the near-complete biomass enzymatic saccharification of desirable corn stalk for high bioethanol production, and all the enzyme-undigestible lignocellulose residues were then examined as active biosorbents for high Cd adsorption. Furthermore, by incubating Trichoderma reesei with the desired corn stalk co-supplied with 0.05% FeCl3 for the secretion of lignocellulose-degradation enzymes in vivo, we examined five secreted enzyme activities elevated by 1.3-3.0-fold in vitro, compared to the control without FeCl3 supplementation. After further supplying 1:2 (w/w) FeCl3 into the T. reesei-undigested lignocellulose residue for the thermal-carbonization process, we generated highly porous carbon with specific electroconductivity raised by 3-12-fold for the supercapacitor. Therefore, this work demonstrates that FeCl3 can act as a universal catalyst for the full-chain enhancement of biological, biochemical, and chemical conversions of lignocellulose substrates, providing a green-like strategy for low-cost biofuels and high-value bioproducts.


Asunto(s)
Celulasa , Celulasa/metabolismo , Zea mays/química , Etanol/metabolismo , Biocombustibles , Lignina/metabolismo , Carbono , Hidrólisis , Biomasa , Fermentación
2.
Molecules ; 26(13)2021 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-34202856

RESUMEN

Banana is a major fruit crop throughout the world with abundant lignocellulose in the pseudostem and rachis residues for biofuel production. In this study, we collected a total of 11 pseudostems and rachis samples that were originally derived from different genetic types and ecological locations of banana crops and then examined largely varied edible carbohydrates (soluble sugars, starch) and lignocellulose compositions. By performing chemical (H2SO4, NaOH) and liquid hot water (LHW) pretreatments, we also found a remarkable variation in biomass enzymatic saccharification and bioethanol production among all banana samples examined. Consequently, this study identified a desirable banana (Refen1, subgroup Pisang Awak) crop containing large amounts of edible carbohydrates and completely digestible lignocellulose, which could be combined to achieve the highest bioethanol yields of 31-38% (% dry matter), compared with previously reported ones in other bioenergy crops. Chemical analysis further indicated that the cellulose CrI and lignin G-monomer should be two major recalcitrant factors affecting biomass enzymatic saccharification in banana pseudostems and rachis. Therefore, this study not only examined rich edible carbohydrates for food in the banana pseudostems but also detected digestible lignocellulose for bioethanol production in rachis tissue, providing a strategy applicable for genetic breeding and biomass processing in banana crops.


Asunto(s)
Biocombustibles , Biomasa , Calor , Lignina/química , Musa/química , Agua , Hidrólisis
3.
Plant Mol Biol ; 101(4-5): 389-401, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31432304

RESUMEN

KEY MESSAGE: Overexpression of cotton cellulose synthase like D3 (GhCSLD3) gene partially rescued growth defect of atcesa6 mutant with restored cell elongation and cell wall integrity mainly by enhancing primary cellulose production. Among cellulose synthase like (CSL) family proteins, CSLDs share the highest sequence similarity to cellulose synthase (CESA) proteins. Although CSLD proteins have been implicated to participate in the synthesis of carbohydrate-based polymers (cellulose, pectins and hemicelluloses), and therefore plant cell wall formation, the exact biochemical function of CSLD proteins remains controversial and the function of the remaining CSLD genes in other species have not been determined. In this study, we attempted to illustrate the function of CSLD proteins by overexpressing Arabidopsis AtCSLD2, -3, -5 and cotton GhCSLD3 genes in the atcesa6 mutant, which has a background that is defective for primary cell wall cellulose synthesis in Arabidopsis. We found that GhCSLD3 overexpression partially rescued the growth defect of the atcesa6 mutant during early vegetative growth. Despite the atceas6 mutant having significantly reduced cellulose contents, the defected cell walls and lower dry mass, GhCSLD3 overexpression largely restored cell wall integrity (CWI) and improved the biomass yield. Our result suggests that overexpression of the GhCSLD protein enhances primary cell wall synthesis and compensates for the loss of CESAs, which is required for cellulose production, therefore rescuing defects in cell elongation and CWI.


Asunto(s)
Arabidopsis/crecimiento & desarrollo , Gossypium/genética , Proteínas de Plantas/fisiología , Arabidopsis/genética , Arabidopsis/metabolismo , Pared Celular/metabolismo , Celulosa/biosíntesis , Celulosa/genética , Regulación de la Expresión Génica de las Plantas , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente/crecimiento & desarrollo , Plantas Modificadas Genéticamente/metabolismo
4.
Int J Mol Sci ; 20(20)2019 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-31600873

RESUMEN

Grain size and weight are two important determinants of grain yield in rice. Although overexpression of sucrose synthase (SUS) genes has led to several improvements on cellulose and starch-based traits in transgenic crops, little is reported about SUS enhancement of hull size and grain weight in rice. In this study, we selected transgenic rice plants that overexpressed OsSUS1-6 genes driven with the maize Ubi promoter. Compared to the controls (wild type and empty vector line), all independent OsSUS homozygous transgenic lines exhibited considerably increased grain yield and grain weights. Using the representative OsSUS3 overexpressed transgenic plants, four independent homozygous lines showed much raised cell numbers for larger hull sizes, consistent with their enhanced primary cell wall cellulose biosynthesis and postponed secondary wall synthesis. Accordingly, the OsSUS3 transgenic lines contained much larger endosperm volume and higher starch levels than those of the controls in the mature grains, leading to increased brown grain weights by 15-19%. Hence, the results have demonstrated that OsSUS overexpression could significantly improve hull size and grain weight by dynamically regulating cell division and starch accumulation in the transgenic rice.


Asunto(s)
División Celular/genética , Grano Comestible , Glucosiltransferasas/metabolismo , Oryza/genética , Oryza/metabolismo , Almidón/metabolismo , Celulosa/biosíntesis , Endospermo/genética , Endospermo/metabolismo , Regulación de la Expresión Génica de las Plantas , Familia de Multigenes , Oryza/clasificación , Fenotipo , Filogenia , Plantas Modificadas Genéticamente
5.
Plant Biotechnol J ; 16(5): 976-988, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-28944540

RESUMEN

Cellulose is an abundant biopolymer and a prominent constituent of plant cell walls. Cellulose is also a central component to plant morphogenesis and contributes the bulk of a plant's biomass. While cellulose synthase (CesA) genes were identified over two decades ago, genetic manipulation of this family to enhance cellulose production has remained difficult. In this study, we show that increasing the expression levels of the three primary cell wall AtCesA6-like genes (AtCesA2, AtCesA5, AtCesA6), but not AtCesA3, AtCesA9 or secondary cell wall AtCesA7, can promote the expression of major primary wall CesA genes to accelerate primary wall CesA complex (cellulose synthase complexes, CSCs) particle movement for acquiring long microfibrils and consequently increasing cellulose production in Arabidopsis transgenic lines, as compared with wild-type. The overexpression transgenic lines displayed changes in expression of genes related to cell growth and proliferation, perhaps explaining the enhanced growth of the transgenic seedlings. Notably, overexpression of the three AtCesA6-like genes also enhanced secondary cell wall deposition that led to improved mechanical strength and higher biomass production in transgenic mature plants. Hence, we propose that overexpression of certain AtCesA genes can provide a biotechnological approach to increase cellulose synthesis and biomass accumulation in transgenic plants.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/enzimología , Celulosa/metabolismo , Glucosiltransferasas/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Biomasa , Pared Celular/enzimología , Expresión Génica , Glucosiltransferasas/genética , Plantas Modificadas Genéticamente , Plantones/enzimología , Plantones/genética , Plantones/crecimiento & desarrollo
6.
Plant Biotechnol J ; 15(9): 1093-1104, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28117552

RESUMEN

Genetic modification of plant cell walls has been posed to reduce lignocellulose recalcitrance for enhancing biomass saccharification. Since cellulose synthase (CESA) gene was first identified, several dozen CESA mutants have been reported, but almost all mutants exhibit the defective phenotypes in plant growth and development. In this study, the rice (Oryza sativa) Osfc16 mutant with substitutions (W481C, P482S) at P-CR conserved site in CESA9 shows a slightly affected plant growth and higher biomass yield by 25%-41% compared with wild type (Nipponbare, a japonica variety). Chemical and ultrastructural analyses indicate that Osfc16 has a significantly reduced cellulose crystallinity (CrI) and thinner secondary cell walls compared with wild type. CESA co-IP detection, together with implementations of a proteasome inhibitor (MG132) and two distinct cellulose inhibitors (Calcofluor, CGA), shows that CESA9 mutation could affect integrity of CESA4/7/9 complexes, which may lead to rapid CESA proteasome degradation for low-DP cellulose biosynthesis. These may reduce cellulose CrI, which improves plant lodging resistance, a major and integrated agronomic trait on plant growth and grain production, and enhances biomass enzymatic saccharification by up to 2.3-fold and ethanol productivity by 34%-42%. This study has for the first time reported a direct modification for the low-DP cellulose production that has broad applications in biomass industries.


Asunto(s)
Celulosa/metabolismo , Glucosiltransferasas/metabolismo , Lignina/metabolismo , Oryza/enzimología , Biomasa , Membrana Celular/metabolismo , Pared Celular/metabolismo , Glucosiltransferasas/genética , Modelos Biológicos , Mutación , Oryza/genética , Oryza/crecimiento & desarrollo , Oryza/ultraestructura , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Tallos de la Planta/enzimología , Tallos de la Planta/genética , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/ultraestructura
7.
Sheng Wu Gong Cheng Xue Bao ; 40(4): 1002-1016, 2024 Apr 25.
Artículo en Zh | MEDLINE | ID: mdl-38658144

RESUMEN

Hemicellulose, as a primary component of plant cell walls, constitutes approximately one third of cell wall dry matter and ranks as the second abundant renewable biomass resource in the nature after cellulose. Hemicellulose is tightly cross-linked with cellulose, lignin and other components in the plant cell wall, leading to lignocellulose recalcitrance. However, precise genetic modifications of plant cell walls can significantly improve the saccharification efficiency of lignocellulose while ensuring normal plant growth and development. We comprehensively review the research progress in the structural distribution of hemicellulose in plant cell walls, the cross-linking between hemicellulose and other components of the cell wall, and the impact of hemicellulose modification on the saccharification efficiency of the cell wall, proving a reference for the genetic improvement of energy crops.


Asunto(s)
Pared Celular , Celulosa , Lignina , Polisacáridos , Pared Celular/metabolismo , Pared Celular/genética , Polisacáridos/metabolismo , Lignina/metabolismo , Celulosa/metabolismo , Plantas/genética , Plantas/metabolismo , Productos Agrícolas/genética , Plantas Modificadas Genéticamente/genética
8.
Water Res ; 256: 121597, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38614030

RESUMEN

Nano and micro-plastics (NMPs, particles diameter <5 mm), as emerging contaminants, have become a major concern in the aquatic environment because of their adverse consequences to aquatic life and potentially human health. Implementing mitigation strategies requires quantifying NMPs mass emissions and understanding their sources and transport pathways from land to riverine systems. Herein, to access NMPs mass input from agricultural soil to riverine system via water-driven soil erosion, we have collected soil samples from 120 cultivated land in nine drainage basins across China in 2021 and quantified the residues of six common types of plastic, including polyvinyl chloride (PVC), polymethyl methacrylate (PMMA), polypropylene (PP), polyethylene (PE), polycarbonate (PC), and polystyrene (PS). NMPs (Σ6plastics) were detected in all samples at concentrations between 3.6 and 816.6 µg/g dry weight (median, 63.3 µg/g) by thermal desorption/pyrolysis-gas chromatography-mass spectrometry. Then, based on the Revised Universal Soil Loss Equation model, we estimated that about 22,700 tonnes of NMPs may enter the Chinese riverine system in 2020 due to agricultural water-driven soil erosion, which occurs primarily from May to September. Our result suggested that over 90% of the riverine NMPs related to agricultural soil erosion in China are attributed to 36.5% of the country's total cultivated land, mainly distributed in the Yangtze River Basin, Southwest Basin, and Pearl River Basin. The migration of NMPs due to water-driven soil erosion cannot be ignored, and erosion management strategies may contribute to alleviating plastic pollution issues in aquatic systems.


Asunto(s)
Monitoreo del Ambiente , Plásticos , Suelo , Suelo/química , China , Agricultura , Ríos/química
9.
Environ Pollut ; 341: 122934, 2024 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-37967709

RESUMEN

Malic acid (MA) plays an important role in plant tolerance to toxic metals, but its effect in restricting the transport of harmful metals remains unclear. In this study, japonica rice NPB and its fragile-culm mutant fc8 with low cellulose and thin cell wall were used to investigate the influence of MA on the accumulation of 4 toxic elements (Cd, Pb, Ni, and Cr) and 8 essential elements (K, Mg, Ca, Fe, Mn, Zn, Cu and Mo) in rice. The results showed that fc8 accumulated less toxic elements but more Ca and glutamate in grains and vegetative organs than NPB. After foliar application with MA at rice anthesis stage, the content of Cd, Pb, Ni significantly decreased by 27.9-41.0%, while those of Ca and glutamate significantly increased in both NPB and fc8. Therefore, the ratios between Cd and Ca in grains of NPB (3.4‰) and fc8 (1.5‰) were greatly higher than that in grains of NPB + MA (1.1‰) and fc8+MA (0.8‰) treatments. Meanwhile, the expression of OsCEAS4,7,8,9 for the cellulose synthesis in secondary cell walls were down-regulated and cellulose content in vegetative organs of NPB and fc8 decreased by 16.7-21.1%. However, MA application significantly up-regulated the expression of GLR genes (OsGLR3.1-3.5) and raised the activity of glutamic-oxalacetic transaminease for glutamate synthesis in NPB and fc8. These results indicate that hazard risks of toxic elements in foods can be efficiently reduced through regulating cellulose biosynthesis and GLR channels in plant by combining genetic modification in vivo and malic acid application in vitro.


Asunto(s)
Metales Pesados , Oryza , Contaminantes del Suelo , Cadmio/análisis , Cromo/metabolismo , Níquel/toxicidad , Níquel/metabolismo , Oryza/genética , Oryza/metabolismo , Regulación hacia Arriba , Regulación hacia Abajo , Plomo/metabolismo , Glutamatos/genética , Glutamatos/metabolismo , Celulosa/metabolismo , Contaminantes del Suelo/análisis , Suelo , Metales Pesados/análisis
10.
Int J Biol Macromol ; 262(Pt 2): 130137, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38354940

RESUMEN

Crop straws provide enormous biomass residues applicable for biofuel production and trace metal phytoremediation. However, as lignocellulose recalcitrance determines a costly process with potential secondary waste liberation, genetic modification of plant cell walls is deemed as a promising solution. Although pectin methylation plays an important role for plant cell wall construction and integrity, little is known about its regulation roles on lignocellulose hydrolysis and trace metal elimination. In this study, we initially performed a typical CRISPR/Cas9 gene-editing for site mutations of OsPME31, OsPME34 and OsPME79 in rice, and then determined significantly upgraded pectin methylation degrees in the young seedlings of three distinct site-mutants compared to their wild type. We then examined distinctively improved lignocellulose recalcitrance in three mutants including reduced cellulose levels, crystallinity and polymerization or raised hemicellulose deposition and cellulose accessibility, which led to specifically enlarged biomass porosity either for consistently enhanced biomass enzymatic saccharification under mild alkali pretreatments or for cadmium (Cd) accumulation up to 2.4-fold. Therefore, this study proposed a novel model to elucidate how pectin methylation could play a unique enhancement role for both lignocellulose enzymatic hydrolysis and Cd phytoremediation, providing insights into precise pectin modification for effective biomass utilization and efficient trace metal exclusion.


Asunto(s)
Oryza , Oryza/metabolismo , Pectinas/metabolismo , Cadmio/metabolismo , Biomasa , Biodegradación Ambiental , Lignina/metabolismo , Celulosa/metabolismo , Metilación
11.
Int J Biol Macromol ; 264(Pt 1): 130448, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38428756

RESUMEN

As lignocellulose recalcitrance principally restricts for a cost-effective conversion into biofuels and bioproducts, this study re-selected the brittle stalk of corn mutant by MuDR-transposon insertion, and detected much reduced cellulose polymerization and crystallinity. Using recyclable CaO chemical for biomass pretreatment, we determined a consistently enhanced enzymatic saccharification of pretreated corn brittle stalk for higher-yield bioethanol conversion. Furthermore, the enzyme-undigestible lignocellulose was treated with two-step thermal-chemical processes via FeCl2 catalysis and KOH activation to generate the biochar with significantly raised adsorption capacities with two industry dyes (methylene blue and Congo red). However, the desirable biochar was attained from one-step KOH treatment with the entire brittle stalk, which was characterized as the highly-porous nanocarbon that is of the largest specific surface area at 1697.34 m2/g and 2-fold higher dyes adsorption. Notably, this nanocarbon enabled to eliminate the most toxic compounds released from CaO pretreatment and enzymatic hydrolysis, and also showed much improved electrochemical performance with specific capacitance at 205 F/g. Hence, this work has raised a mechanism model to interpret how the recalcitrance-reduced lignocellulose is convertible for high-yield bioethanol and multiple-function biochar with high performance.


Asunto(s)
Celulosa , Carbón Orgánico , Zea mays , Celulosa/química , Zea mays/química , Polimerizacion , Colorantes
12.
Planta ; 237(6): 1585-97, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23508664

RESUMEN

Cotton fiber is an excellent model system of cellulose biosynthesis; however, it has not been widely studied due to the lack of information about the cellulose synthase (CESA) family of genes in cotton. In this study, we initially identified six full-length CESA genes designated as GhCESA5-GhCESA10. Phylogenetic analysis and gene co-expression profiling revealed that CESA1, CESA2, CESA7, and CESA8 were the major isoforms for secondary cell wall biosynthesis, whereas CESA3, CESA5, CESA6, CESA9, and CESA10 should involve in primary cell wall formation for cotton fiber initiation and elongation. Using integrative analysis of gene expression patterns, CESA protein levels, and cellulose biosynthesis in vivo, we detected that CESA8 could play an enhancing role for rapid and massive cellulose accumulation in Gossypium hirsutum and Gossypium barbadense. We found that CESA2 displayed a major expression in non-fiber tissues and that CESA1, a housekeeping gene like, was predominantly expressed in all tissues. Further, a dynamic alteration was observed in cell wall composition and a significant discrepancy was observed between the cotton species during fiber elongation, suggesting that pectin accumulation and xyloglucan reduction might contribute to cell wall transition. In addition, we discussed that callose synthesis might be regulated in vivo for massive cellulose production during active secondary cell wall biosynthesis in cotton fibers.


Asunto(s)
Celulosa/biosíntesis , Fibra de Algodón , Glucosiltransferasas/metabolismo , Gossypium/enzimología , Proteínas de Plantas/metabolismo , Western Blotting , Pared Celular/metabolismo , Regulación de la Expresión Génica de las Plantas , Glucosiltransferasas/química , Glucosiltransferasas/genética , Gossypium/genética , Hipocótilo/enzimología , Hipocótilo/crecimiento & desarrollo , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/metabolismo , Familia de Multigenes , Proteínas de Plantas/química , Proteínas de Plantas/genética , Especificidad por Sustrato
13.
Adv Sci (Weinh) ; 10(21): e2301427, 2023 07.
Artículo en Inglés | MEDLINE | ID: mdl-37173819

RESUMEN

Most of the current bioadhesives cannot perform well on bleeding tissues while postoperative adhesion is a general but serious clinical issue. Here, a three-layer biodegradable Janus tissue patch (J-TP) that is able to simultaneously enable efficient closure of bleeding wounds with significantly promoted clotting ability and suppressed postoperative adhesion of tissues is reported. A dry adhesive hydrogel bottom layer of the J-TP can form rapid (within 15 s) and strong (tensile strength up to 98 kPa) adhesion to bleeding/wet tissues with high bursting pressure (about 312.5 mmHg on a sealed porcine skin) through hydrogen binding and covalent conjugation between the carboxyl & N-hydroxy succinimide (NHS) groups of hydrogel and the primary amine groups of tissues, while the phosphonic motifs can significantly reduce blood loss (by 81% on a rat bleeding liver model) of bleeding wounds. A thin polylactic acid (PLA) middle layer can improve the tensile strength (by 132%) of the J-TP in wet conditions while the grafted zwitterionic polymers can effectively prevent postoperative tissue adhesion and inflammatory reaction. This J-TP may be a promising tissue patch to assist the clinical treatment of injured bleeding tissues with inhibited postoperative adhesion.


Asunto(s)
Adhesivos Tisulares , Porcinos , Ratas , Animales , Adherencias Tisulares/prevención & control , Adhesivos Tisulares/uso terapéutico , Adhesivos Tisulares/farmacología , Hidrogeles/farmacología , Adhesivos , Polímeros
14.
PLoS One ; 18(7): e0287605, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37410735

RESUMEN

In areas with large differences between day and night temperature, the freeze-thaw cycle and frost heaving force in rock mass generate cracks within the rock, which seriously threatens the stability and safety of geotechnical engineering structures and surrounding buildings. This problem can be solved by developing a reasonable model that accurately represents the rock creep behavior. In this study, we developed a nonlinear viscoelastic-plastic creep damage model by introducing material parameters and a damage factor while connecting an elastomer, a viscosity elastomer, a Kelvin element, and a viscoelastic-plastic element in series. One- and three-dimensional creep equations were derived, and triaxial creep data were used to determine the model parameters and to validate the model. The results showed that the nonlinear viscoelastic-plastic creep damage model can accurately describe rock deformation in three creep stages under freeze-thaw cycles. In addition, the model can describe the time-dependent strain in the third stage. Parameters G1, G2, and η20' decrease exponentially with the increase in the number of freeze-thaw cycles while parameter λ increases exponentially. These results provide a theoretical basis for studying the deformation behavior and long-term stability of geotechnical engineering structures in areas with large diurnal temperature differences.


Asunto(s)
Dinámicas no Lineales , Plásticos , Congelación , Temperatura , Elastómeros
15.
Bioresour Technol ; 369: 128315, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36414143

RESUMEN

Lignocellulose represents the most abundant carbon-capturing substance that is convertible for biofuels and bioproduction. Although biomass pretreatments have been broadly applied to reduce lignocellulose recalcitrance for enhanced enzymatic saccharification, they mostly require strong conditions with potential secondary waste release. By classifying all major types of pretreatments that have been recently conducted with different sources of lignocellulose substrates, this study sorted out their distinct roles for wall polymer extraction and destruction, leading to the optimal pretreatments evaluated for cost-effective biomass enzymatic saccharification to maximize biofuel production. Notably, all undigestible lignocellulose residues are also aimed for effective conversion into value-added bioproduction. Meanwhile, desired pretreatments were proposed for the generation of highly-valuable nanomaterials such as cellulose nanocrystals, lignin nanoparticles, functional wood, carbon dots, porous and graphitic nanocarbons. Therefore, this article has proposed a novel strategy that integrates cost-effective and green-like pretreatments with desirable lignocellulose substrates for a full lignocellulose utilization with zero-biomass-waste liberation.


Asunto(s)
Biocombustibles , Lignina , Lignina/química , Biocombustibles/análisis , Celulosa/química , Pared Celular , Biomasa
16.
Bioresour Technol ; 369: 128437, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36470495

RESUMEN

In this study, optimal ultrasound pretreatment was performed with recalcitrance-reduced rice mutant straw to effectively extract lignin and hemicellulose for improved cellulose accessibility. Intermittent ultrasound-assistant enzymatic hydrolyses were followed to maintain more cellulases unlock and less cellulose surface block with lignin for raised hexose yield at 81 % (% cellulose) and bioethanol concentration at 9.9 g/L, which was higher than those of other mechanical pretreatments as previously conducted. Using all enzyme-undigestible lignocellulose residues, this work generated the biochar with the highest porosity (SBET at 2971 m2/g) among all biomass-based biochar obtained from previous studies. Furthermore, the biochar were respectively examined with high adsorption capacity for Congo red and methylene blue at 7946 mg/g and 861 mg/g. Therefore, this study has demonstrated a green-like process technology for high-yield bioethanol and high-porosity biochar with full biomass utilization by integrating optimal ultrasound pretreatment with intermittent ultrasound-assistant enzymatic hydrolyses of recalcitrance-reduced lignocellulose in crop straws.


Asunto(s)
Celulasas , Oryza , Lignina/química , Oryza/química , Etanol , Adsorción , Porosidad , Celulosa/química , Hidrólisis , Biomasa
17.
Nat Commun ; 14(1): 1100, 2023 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-36841862

RESUMEN

Plant cellulose microfibrils are increasingly employed to produce functional nanofibers and nanocrystals for biomaterials, but their catalytic formation and conversion mechanisms remain elusive. Here, we characterize length-reduced cellulose nanofibers assembly in situ accounting for the high density of amorphous cellulose regions in the natural rice fragile culm 16 (Osfc16) mutant defective in cellulose biosynthesis using both classic and advanced atomic force microscopy (AFM) techniques equipped with a single-molecular recognition system. By employing individual types of cellulases, we observe efficient enzymatic catalysis modes in the mutant, due to amorphous and inner-broken cellulose chains elevated as breakpoints for initiating and completing cellulose hydrolyses into higher-yield fermentable sugars. Furthermore, effective chemical catalysis mode is examined in vitro for cellulose nanofibers conversion into nanocrystals with reduced dimensions. Our study addresses how plant cellulose substrates are digestible and convertible, revealing a strategy for precise engineering of cellulose substrates toward cost-effective biofuels and high-quality bioproducts.


Asunto(s)
Celulosa , Nanofibras , Celulosa/química , Nanofibras/química , Microscopía de Fuerza Atómica , Azúcares , Pared Celular
18.
Environ Pollut ; 268(Pt A): 115756, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33162209

RESUMEN

Microplastics have emerged as a new anthropogenic substrate that can readily be colonized by microorganisms. Nevertheless, microbial community succession and assembly among different microplastics in nearshore mariculture cages remains poorly understood. Using an in situ incubation experiment, 16S rRNA gene amplicon sequencing, and the neutral model, we investigated the prokaryotic communities attached to polyethylene terephthalate (PET), polyethylene (PE), and polypropylene (PP) in a mariculture cage in Xiangshan Harbor, China. The α-diversities and compositions of microplastic-attached prokaryotic communities were significantly distinct from free-living and small particle-attached communities in the surrounding water but relatively similar to the large particle-attached communities. Although a distinct prokaryotic community was developed on each type of microplastic, the communities on PE and PP more closely resembled each other. Furthermore, the prokaryotic community dissimilarity among all media (microplastics and water fractions) tended to decrease over time. Hydrocarbon-degrading bacteria Alcanivorax preferentially colonized PE, and the genus Vibrio with opportunistically pathogenic members has the potential to colonize PET. Additionally, neutral processes dominated the prokaryotic community assembly on PE and PP, while selection was more responsible for the prokaryotic assembly on PET. The assembly of Planctomycetaceae and Thaumarchaeota Marine Group I taxa on three microplastics were mainly governed by selection and neutral processes, respectively. Our study provides further understanding of microplastic-associated microbial ecology in mariculture environments.


Asunto(s)
Plásticos , Contaminantes Químicos del Agua , China , Microplásticos , ARN Ribosómico 16S , Contaminantes Químicos del Agua/análisis
19.
Carbohydr Polym ; 265: 118070, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33966834

RESUMEN

Potato is a major food crop with enormous biomass straw, but lignocellulose recalcitrance causes a costly bioethanol conversion. Here, we selected the cytochimera (Cyt) potato samples showing significantly-modified lignocellulose and much increased soluble sugars and starch by 2-4 folds in mature straws. Under two pretreatments (8 min liquid hot water; 5% CaO) at minimized conditions, the potato Cyt straw showed complete enzymatic saccharification. Further performing yeast fermentation with all hexoses released from soluble sugars, starch and lignocellulose in the Cyt straw, this study achieved a maximum bioethanol yield of 24 % (% dry matter), being higher than those of other bioenergy crops as previously reported. Hence, this study has proposed a novel mechanism model on the reduction of major lignocellulose recalcitrance and regulation of carbon assimilation to achieve cost-effective bioethanol production under optimal pretreatments. This work also provides a sustainable strategy for utilization of potato straws with minimum waste release.


Asunto(s)
Biocombustibles , Etanol/metabolismo , Lignina/química , Solanum tuberosum/química , Almidón/química , Biomasa , Celulasa/metabolismo , Celulosa/química , Productos Agrícolas/química , Etanol/química , Fermentación , Hidrólisis , Lignina/metabolismo , Poliploidía , Saccharomyces cerevisiae/metabolismo , Solanum tuberosum/genética , Almidón/metabolismo
20.
J Hazard Mater ; 406: 124727, 2021 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-33310336

RESUMEN

Improving biomass enzymatic saccharification is effective for crop straw utilization, whereas phytoremediation is efficient for trace metal elimination from polluted agricultural soil. Here, we found that the green proteins extracted from Amaranthus leaf tissue could act as active biosurfactant to remarkably enhance lignocellulose enzymatic saccharification for high bioethanol production examined in eight grassy and woody plants after mild chemical and green-like pretreatments were performed. Notably, this study estimated that total green proteins supply collected from one-hectare-land Amaranth plants could even lead to additional 6400-12,400 tons of bioethanol, being over 10-fold bioethanol yield higher than those of soybean seed proteins and chemical surfactant. Meanwhile, the Amaranth green proteins were characterized as a dominated biosorbent for multiple trace metals (Cd, Pb, As) adsorption, being 2.9-6 folds higher than those of its lignocellulose. The Amaranth plants were also assessed to accumulate much more trace metals than all other plants as previously examined from large-scale contaminated soils. Furthermore, the Amaranth green proteins not only effectively block lignin to release active cellulases for the mostly enhanced biomass hydrolyzes, but also efficiently involve in multiple chemical bindings with Cd, which should thus address critical issues of high-costly biomass waste utilization and low-efficient trace metal remediation.


Asunto(s)
Amaranthus , Metales Pesados , Contaminantes del Suelo , Agricultura , Biodegradación Ambiental , Lignina , Metales Pesados/análisis , Suelo , Contaminantes del Suelo/análisis
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