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1.
Bioresour Technol ; 291: 121876, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31377509

RESUMO

Composting is used widely for recycling spent mushroom substrate (SMS). This study investigated the effects of inoculating a lignocellulose-degrading consortium at two levels comprising 0% (control: CK) and 10% (T) on the fungal community and cellulose-degrading genes during SMS co-composting with swine manure. Lignocellulose degradation rate in T was 8.77-34.45% higher compared with CK. Inoculation affected the distribution of the fungal community, increased the community diversity, and inhibited pathogens. Network analysis showed that inoculation changed the co-occurrence patterns of the fungal communities and made the co-composting system more stable. The relative abundances of glycoside hydrolase genes GH3E (fungal GH3), GH6, and GH7 were 0.45, 0.09, and 0.39 logs higher in T, respectively, than CK. Partial least-squares path modeling suggested that the variations in cellulose-degrading genes were driven mainly by changes in the fungal community during co-composting. Therefore, the lignocellulose-degrading consortium accelerated the transformation of lignocellulose to facilitate safer composting.


Assuntos
Agaricales/metabolismo , Compostagem , Lignina/metabolismo , Esterco/microbiologia , Animais , Micobioma , Suínos
2.
World J Microbiol Biotechnol ; 35(8): 125, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363859

RESUMO

The global need to develop sustainable materials and products from non-fossil raw material is pushing industry to utilize side-streams more efficiently using green processes. Aromatic lignin, the world's second most abundant biopolymer, has multiple attractive properties which can be exploited in various ways instead of being burnt or used as animal feed. Lignin's poor water solubility and its highly branched and random structure make it a challenging biopolymer to exploit when developing novel technologies for the preparation of tailored nanobiomaterials for value-added applications. The notable number of scientific publications focusing on the formation and modification of technical lignin in nanoparticulate morphology show that these bottlenecks could be solved using lignin in the form of colloidal particles (CLPs). These particles are very stable at wide pH range (4-11) and easily dispersible in organic solvents after stabilized via cross-linking. Negative hydroxyl groups on the CLP surface enable multiple enzymatic and chemical modifications e.g. via polymerization reactions and surface-coating with positive polymers. This contribution highlights how tailored CLPs could be innovatively exploited in different the state-of-the-art applications such as medicine, foods, and cosmetics.


Assuntos
Química Verde/métodos , Lignina/síntese química , Lignina/metabolismo , Nanopartículas/química , Nanopartículas/metabolismo , Animais , Biotransformação , Solubilidade
3.
Bioresour Technol ; 291: 121882, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31377512

RESUMO

The aim of this study is to assess the effectiveness of protein-like precursors addition on promoting humification process during lignocellulose-like biomass composting through adding amino acids to compost. The humification indexes of R1 and R2 was significantly higher than that of CK (P < 0.05). The decreasing ratio of Maillard precursor concentration of R2 and R1 was higher than CK. Amino acids addition affected the bacteria community and environmental factors during composting. Variance partitioning analysis showed that humification process was strengthened with environmental factors, bacteria community, Maillard precursors. Structural equation model (SEM) analysis showed that amino acids had substantial impact on promoting humic acid (HA) formation. The combined application of protein-like wastes and lignocellulose-like wastes was suggested to improve carbon sequestration. This study lays a foundation for economically and effectively managing different types of straws by composting.


Assuntos
Aminoácidos/metabolismo , Biomassa , Compostagem , Lignina/metabolismo , Precursores de Proteínas/farmacologia , Substâncias Húmicas/análise
4.
Bioresour Technol ; 291: 121844, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31400704

RESUMO

A low-temperature sodium hydroxide (NaOH) pretreatment for sugarcane bagasse (SCB) was obtained via the surface response design in this study. However, a large quantity of water consumption and wastewater generation which have been the common problems for alkaline pretreatment of lignocellulose still exists in this pretreatment. In order to reduce water consumption and wastewater generation, this study attempted to perform enzymatic hydrolysis and fermentation of NaOH-treated SCB without washing process. It showed that after pretreatment and solid-liquid separation, NaOH-treated SCB could be directly hydrolysed by cellulase via pH and solid-liquid adjustment without washing steps, and the maximum enzymatic hydrolysis efficiency could reach to 70.2%. A domesticated Saccharomyces cerevisiae Y2034 which can endure 6-times diluted BL was obtained, and realized 67.5% ethanol yield from the enzymatic hydrolysate of unwashed NaOH-treated SCB. It provided a clue for converting NaOH-treated lignocellulose to ethanol at low water consumption and wastewater generation.


Assuntos
Celulose/química , Etanol/química , Saccharum/química , Hidróxido de Sódio/química , Celulose/metabolismo , Temperatura Baixa , Etanol/metabolismo , Fermentação , Hidrólise , Lignina/química , Lignina/metabolismo , Saccharomyces cerevisiae/metabolismo , Saccharum/metabolismo , Águas Residuárias/química
5.
J Agric Food Chem ; 67(35): 9858-9867, 2019 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-31389230

RESUMO

Farnesene is an important chemical platform for many industrial products, such as biofuels and polymers. We performed high-efficiency utilization of corncobs for ß-farnesene production by separate hydrolysis and fermentation with an optimized Escherichia coli strain. First, we developed a recycling strategy for both corncob pretreatment and cellulose hydrolysis, which saved great amounts of pretreatment reagents and presented a 96.83% cellulose conversion rate into glucose. However, the corncob hydrolysate strongly repressed cell growth and ß-farnesene production, being caused by high-concentrated citrate. Through expressing a heterologous ATP citrate lyase and screening for a suitable expression host, an optimized strain was constructed that produced ß-farnesene at 4.06 g/L after 48 h in a 5 L fermenter, representing an approximately 2.3-fold increase over the initial strain. Therefore, the proposed strategy about the recycling process and repression elimination was successful and suitable for the production of lignocellulosic-based ß-farnesene, which can be further studied to scale up for industrialization.


Assuntos
Escherichia coli/genética , Escherichia coli/metabolismo , Lignina/metabolismo , Sesquiterpenos/metabolismo , Fermentação , Glucose/metabolismo , Hidrólise , Engenharia Metabólica , Reciclagem , Resíduos/análise , Zea mays/química , Zea mays/microbiologia
6.
Food Chem ; 301: 125224, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31374530

RESUMO

This study was the first investigation into the main inducers of two lignifications by examining the changes of physicochemical properties and gene expression in king oyster mushrooms, under different conditions, during 21 days of storage. The results showed that the toughness, firmness and gumminess of the no-wounding treatment decreased to approximately 75-82.5% of the initial values, and the lignin content and expression of Pe4CL1 and Pe4CL3 decreased by 21-40% and 22-77%, respectively, in comparison to those of the other treatments in the first lignification. These findings indicated that wounding was the main factor inducing the first lignification. The second lignification of tested mushrooms was positively correlated with reactive oxygen species (ROS)-mediated senescence, accompanied by increased malondialdehyde (MDA) content, electrolyte leakage rate and mitochondrial dysfunction, which showed that ROS-mediated senescence played an essential role in the second lignification. This study is helpful for effective strategies to reduce lignification in stored mushrooms.


Assuntos
Pleurotus/crescimento & desenvolvimento , Pleurotus/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Lignina/metabolismo , Malondialdeído/metabolismo , Pleurotus/fisiologia
7.
Bioresour Technol ; 289: 121749, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31323711

RESUMO

Acetone-butanol-ethanol fermentation suffers from high substrate cost and low butanol titer and yield. In this study, engineered Clostridium tyrobutyricum CtΔack-adhE2 immobilized in a fibrous-bed bioreactor was used for butanol production from glucose and xylose present in the hydrolysates of low-cost lignocellulosic biomass including corn fiber, cotton stalk, soybean hull, and sugarcane bagasse. The biomass hydrolysates obtained after acid pretreatment and enzymatic hydrolysis were supplemented with corn steep liquor and used in repeated-batch fermentations. Butanol production with high titer (∼15 g/L), yield (∼0.3 g/g), and productivity (∼0.3 g/L∙h) was obtained from cotton stalk, soybean hull, and sugarcane bagasse hydrolysates, while corn fiber hydrolysate with higher inhibitor contents gave somewhat inferior results. The fermentation process was stable for long-term operation without any noticeable degeneration, demonstrating its potential for industrial application. A techno-economic analysis showed that n-butanol could be produced from lignocellulosic biomass using this novel fermentation process at ∼$2.5/gal for biofuel application.


Assuntos
Biomassa , Reatores Biológicos , Butanóis/metabolismo , Clostridium tyrobutyricum/metabolismo , Lignina/metabolismo , Celulose/metabolismo , Fermentação , Glucose/metabolismo , Hidrólise , Inativação Metabólica , Saccharum/metabolismo , Xilose/metabolismo
8.
Sci Total Environ ; 691: 885-895, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31326812

RESUMO

Mathematical model applications for the bioaugmented anaerobic digestion (BAD) process seem to be lacking in the scientific literature, even more so when related to microbiological data. The present study suggests a simplified mathematical model to investigate and simulate the process kinetics of bioaugmented anaerobic digestion (BAD) aimed at improving biogas production from wheat straw (WS). Bioaugmented conditions were obtained through a mixed inoculum of anaerobic ruminal fungi (ARF) and hydrogen-producing fermenting bacteria (F210) added to a methanogenic inoculum. The investigation focused on two process configurations characterized by a mono (I-BAD) and two-stage (II-BAD) process and a conventional anaerobic digestion (AD) control test. Each configuration was used on two operating scales (i.e., 120 ml and 12,000 ml reactor volume) to provide different data sets for the calibration and validation of the mathematical model proposed. The model calibration step was used to determine the optimal values of selected parameters displaying higher significance for experimental result predictability. The model calibration results highlighted a similar behavior for both BAD tests, which was further strengthened by a statistical analysis supporting the observed correlation regardless of the BAD configuration involved. The BAD configuration always enhanced the CH4 production (>70%) with a faster kinetic in the II-BAD test. The microbiological results support the superior performance of the II-BAD test, displaying higher Archaea fractions (up to 14.5% on day 23) with values more than double compared to I-BAD and triple compared to the AD test. Furthermore, the presence of Methanosarcina inside the Archaea guild (6.4% and 4.5% at days 11 and 61, respectively) ensures a greater diversification of the metabolic pathways and supports the strength of the process performance. Cell density values are strongly in line with these results.


Assuntos
Biocombustíveis , Anaerobiose , Archaea/metabolismo , Biomassa , Celulose/metabolismo , Lignina/metabolismo
9.
Bioresour Technol ; 289: 121708, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31271914

RESUMO

This study investigated simultaneous lignocellulose fractionation and conversion in a one-pot reaction using an aqueous choline chloride/methyl isobutyl ketone (ChCl/MIBK) biphasic solvent system. Under the optimized condition (170 °C, 60 min, 0.6 wt% H2SO4, 10.7 wt% solid loading), the biphasic solvent solubilized 96% xylan in raw switchgrass, which was simultaneously converted to furfural with a yield of 84.04%. The biphasic solvent was also able to selectively extract lignin, which had a high purity (93.1%), and uncondensed moieties (i.e., Hibbert's ketone), as well as decreased molecular weight and polydispersity index. The resultant pulp was enriched with cellulose (73.3%), which can be completely hydrolyzed into glucose within 48 h via enzymatic hydrolysis. Aqueous ChCl was successfully recycled and reused for atleast three cycles with similar performance in switchgrass fractionation. This study demonstrated that aqueous ChCl/MIBK biphasic system was an effective solvent system for co-production of furfural, high quality technical lignin and digestible cellulose for further upgrading.


Assuntos
Biomassa , Furaldeído/metabolismo , Lignina/metabolismo , Fracionamento Químico , Colina/química , Glucose/metabolismo , Hidrólise , Metil n-Butil Cetona/química , Panicum/metabolismo , Solventes
10.
Bioresour Technol ; 289: 121704, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31276990

RESUMO

Rhodococcus sp. YHY01 was studied to utilize various lignin derived aromatic compounds. It was able to utilize p-coumaric acid, cresol, and 2,6 dimethoxyphenol and resulted in biomass production i.e. 0.38 g dcw/L, 0.25 g dcw/L and 0.1 g dcw/L, and lipid accumulation i.e. 49%, 40%, 30%, respectively. The half maximal inhibitory concentration (IC50) value for p-coumaric acid (13.4 mM), cresol (7.9 mM), and 2,6 dimethoxyphenol (3.4 mM) was analyzed. Dimethyl sulfoxide (DMSO) solubilized barley straw lignin fraction was used as a carbon source for Rhodococcus sp. YHY01 and resulted in 0.130 g dcw/L with 39% w/w lipid accumulation. Major fatty acids were palmitic acid (C16:0) 51.87%, palmitoleic acid (C16:l) 14.90%, and oleic acid (C18:1) 13.76%, respectively. Properties of biodiesel produced from barley straw lignin were as iodine value (IV) 27.25, cetane number (CN) 65.57, cold filter plugging point (CFPP) 14.36, viscosity (υ) 3.81, and density (ρ) 0.86.


Assuntos
Biocombustíveis , Hordeum/química , Lignina/metabolismo , Rhodococcus/metabolismo , Biomassa , Ácidos Graxos/metabolismo , Lignina/química
11.
J Basic Microbiol ; 59(8): 784-791, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31259434

RESUMO

Laccases are multicopper oxidases with high potential for industrial applications. Several basidiomycete fungi are natural producers of this enzyme; however, the optimization of production and selection of inducers for increased productivity coupled with low costs is necessary. Lignocellulosic residues are important lignin sources and potential inducers for laccase production. Pinus taeda, a dominant source of wood-based products, has not been investigated for this purpose yet. The aim of this study was to evaluate the production of laccase by the basidiomycete fungus Ganoderma lucidum in the presence of different inducers in submerged and solid-state fermentation. The results of submerged fermentation in presence of 5 µM CuSO 4 , 2 mM ferulic acid, 0.1 g/L P. taeda sawdust, or 0.05 g/L Kraft lignin indicated that although all the tested inducers promoted increase in laccase activity in specific periods of time, the presence of 2 mM ferulic acid resulted in the highest value of laccase activity (49 U/L). Considering the submerged fermentation, experimental design following the Plackett-Burman method showed that the concentrations of ferulic acid and P. taeda sawdust had a significant influence on the laccase activity. The highest value of 785 U/L of laccase activity on submerged fermentation was obtained on the seventh day of cultivation. Finally, solid-state fermentation cultures in P. taeda using ferulic acid or CuSO 4 as inducers resulted in enzymatic activities of 144.62 and 149.89 U/g, respectively, confirming the potential of this approach for laccase production by G. lucidum.


Assuntos
Fermentação , Lacase/biossíntese , Reishi/metabolismo , Sulfato de Cobre/metabolismo , Ácidos Cumáricos/metabolismo , Meios de Cultura/metabolismo , Lacase/metabolismo , Lignina/metabolismo , Pinus/metabolismo , Reishi/enzimologia , Fatores de Tempo
12.
Bioresour Technol ; 291: 121837, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31353166

RESUMO

Microalgal biomass is a renewable energy source and is considered as a crucial solution in the increasing energy demand and greenhouse gas emissions. Through various thermochemical conversion processes such as torrefaction, pyrolysis, liquefaction, and gasification, biomass can be converted to different bioenergy products. However, the production of these bioenergy products through the aforesaid thermochemical processes entails raw material consumption, energy consumption, and environmental impact. A multitude of studies has been conducted to evaluate the environmental impact of bioenergy products for specific thermochemical processes on a specific biomass feedstock using life cycle assessment. This study aims to comprehensively review the life cycle assessment of bioenergy products from microalgal biomass together with lignocellulosic biomass and through different thermochemical processes. The study identifies the current challenges and potential future works of bioenergy production from different thermochemical processes in the perspective of a life cycle assessment framework.


Assuntos
Biocombustíveis , Lignina/metabolismo , Microalgas/metabolismo , Biomassa , Humanos
13.
J Agric Food Chem ; 67(25): 7082-7086, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31199642

RESUMO

Vitamins are important nutrients for many fermentations, but they are generally costly. Agricultural lignocellulose biomass contains considerable amounts of vitamin B compounds, but these water-soluble vitamins are easily lost into wastewater discharge during pretreatment or detoxification of lignocellulose in biorefinery processes. Here, we showed that the dry acid pretreatment and biodetoxification process allowed the preservation of significant amounts of vitamin B, which promoted l-lactic acid fermentation efficiency significantly. Supplementation with specific vitamin B compounds, VB3 and VB5, into corn stover hydrolysate led to further increases of cellulosic l-lactic acid yield and fermentation rates. This study provided a new solution for the enhancement of biorefinery fermentation efficiency by using vitamin B compounds in lignocellulose biomass.


Assuntos
Ácido Láctico/metabolismo , Lignina/metabolismo , Pediococcus acidilactici/metabolismo , Complexo Vitamínico B/metabolismo , Fermentação , Hidrólise , Lignina/química , Pediococcus acidilactici/crescimento & desenvolvimento , Caules de Planta/química , Caules de Planta/metabolismo , Caules de Planta/microbiologia , Resíduos/análise , Zea mays/química , Zea mays/metabolismo , Zea mays/microbiologia
14.
Environ Sci Pollut Res Int ; 26(22): 22189-22196, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31147997

RESUMO

Effectiveness of steam explosion (SE) pretreatment for deconstructing the complex structural carbohydrates (SC) and lignin recalcitrance properties of rice straw (RS) for conjunctive improvement of biofuel yield and waste valorization was evaluated. This work exhibited successful pretreatment of RS at a different pressure (1.2, 1.5, and 1.8 MPa) and retention (3, 6, 9, and 12 min) for enhancement of SC contribution to biomethane production. Regression analysis demonstrated that SE pretreatment efficiency improved at high-temperature and short-retention time for biodegradation of RS. Maximum cumulative methane yield (EMY) achieved 254.8 mL/gvs at 1.2 MPa (3 min) of SE-treated RS with 62.7% of very significant improvement compared with untreated RS (156.6 mL/gvs). Furthermore, solid fraction of xylose, arabinose, cellobiose, glucose, and acid-soluble lignin in SE-treated RS of 1.2 MPa (3 min) were biodegraded by 27.4%, 46.4%, 100%, 48.8%, and 14.1%, respectively, after anaerobic digestion. Therefore, SE pretreatment was an encouraging approach for enhancing SC conversion to biomethane and waste resource to circular economy.


Assuntos
Lignina/metabolismo , Metano/metabolismo , Oryza/química , Anaerobiose , Biodegradação Ambiental , Biocombustíveis , Carboidratos , Explosões , Metano/química , Vapor
15.
Plant Mol Biol ; 101(3): 235-255, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31254267

RESUMO

KEY MESSAGE: The core set of biosynthetic genes potentially involved in developmental lignification was identified in the model C4 grass Setaria viridis. Lignin has been recognized as a major recalcitrant factor negatively affecting the processing of plant biomass into bioproducts. However, the efficient manipulation of lignin deposition in order to generate optimized crops for the biorefinery requires a fundamental knowledge of several aspects of lignin metabolism, including regulation, biosynthesis and polymerization. The current availability of an annotated genome for the model grass Setaria viridis allows the genome-wide characterization of genes involved in the metabolic pathway leading to the production of monolignols, the main building blocks of lignin. Here we performed a comprehensive study of monolignol biosynthetic genes as an initial step into the characterization of lignin metabolism in S. viridis. A total of 56 genes encoding bona fide enzymes catalyzing the consecutive ten steps of the monolignol biosynthetic pathway were identified in the S. viridis genome. A combination of comparative phylogenetic studies, high-throughput expression analysis and quantitative RT-PCR analysis was further employed to identify the family members potentially involved in developmental lignification. Accordingly, 14 genes clustered with genes from closely related species with a known function in lignification and showed an expression pattern that correlates with lignin deposition. These genes were considered the "core lignin toolbox" responsible for the constitutive, developmental lignification in S. viridis. These results provide the basis for further understanding lignin deposition in C4 grasses and will ultimately allow the validation of biotechnological strategies to produce crops with enhanced processing properties.


Assuntos
Lignina/metabolismo , Poaceae/metabolismo , Biomassa , Vias Biossintéticas , Coenzima A Ligases/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Funções Verossimilhança , Metiltransferases/metabolismo , Fenilalanina Amônia-Liase/metabolismo , Filogenia , Plantas Geneticamente Modificadas/metabolismo , Transcinamato 4-Mono-Oxigenase/metabolismo
16.
Environ Monit Assess ; 191(7): 440, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31203473

RESUMO

Production of quality jute fibre primarily depends on the retting process of jute. However, the quality of retting water is of great concern because of the scarcity of available water bodies for retting. A study conducted on physico-chemical and microbiological changes in retting water (pre- and post-retting) from four intensively jute-growing districts namely Nadia, North 24 Parganas, Hooghly and South Dinajpur of West Bengal, India, during jute retting. The post-retting water samples recorded lower pH (6.22 to 7.08) and higher EC (electrical conductivity) (0.509 to 0.850 ds/m) compared with pre-retting water samples (pH 6.63 to 7.44; EC 0.197 to 0.330 ds/m) collected from all the four districts under study. The biological oxygen demand (BOD) and chemical oxygen demand (COD) increased several folds in the post-retting water samples indicating very high microbial growth and activities and depleted oxygen level compared with pre-retting water. The Ca + Mg (calcium + magnesium) content in pre-retting water was high (24.15 to 36.60 ppm) which raised further (61.30 to 103.67 ppm) in post-retting water, while the bicarbonate content also increased and ranged between 2.72 and 6.81 me/l in post-retting water compared with its status in pre-retting water (1.30 to 3.15 me/l). The post-retting water was found to be a rich source of nutrients like nitrogen (N), phosphorus (P), iron (Fe), manganese (Mn), zinc (Zn) and copper (Cu) which increased substantially because of jute retting as compared with their status in pre-retting water. The population of pectinolytic, xylanolytic, cellulolytic and ligninolytic bacterial cfu (colony forming unit) increased by 1.5 times in post-retting water as compared with pre-retting water, because these specific bacterial population were involved in the degradation of pectin, xylan, cellulose and lignin during retting of jute. Thus, post-retting water can be judiciously used as a potent source of primary, secondary and micronutrients for succeeding crops besides having higher BOD and COD as a result of higher microbial growth related to jute retting.


Assuntos
Bactérias/metabolismo , Corchorus/metabolismo , Lignina/metabolismo , Água/metabolismo , Bicarbonatos/análise , Cálcio/análise , Celulose , Monitoramento Ambiental , Índia , Magnésio/análise , Oxigênio/metabolismo
17.
Food Chem ; 295: 607-612, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31174802

RESUMO

The purpose of this study is to investigate the effects of sodium nitroprusside (SNP) treatment after harvest on the activity of antioxidative enzymes and the phenylpropanoid pathway of blueberries. Blueberry fruits were dipped in 1.0 mmol/L SNP solution for 10 min and stored at 4 °C. Fruits treated with distilled water were used as the control. The results indicated that SNP significantly inhibited the increase of weight loss and enhanced the ascorbic acid content of blueberry fruit. Moreover, SNP increased the activity of phenylalanine ammonia-lyase, 4-coumarate-CoA ligase, polyphenol oxidase, superoxide dismutase, glutathione reductase, ascorbate peroxidase, peroxidase, and hydrogen peroxide in blueberry fruit. The accumulation of lignin and anthocyanin in the fruit was also stimulated by the SNP treatment. These results demonstrate that SNP treatment could maintain the antioxidant ability of blueberries by regulating the phenylpropanoid pathway and antioxidant enzymes.


Assuntos
Antioxidantes/metabolismo , Mirtilos Azuis (Planta)/efeitos dos fármacos , Nitroprussiato/farmacologia , Antocianinas/metabolismo , Antioxidantes/química , Ascorbato Peroxidases/metabolismo , Ácido Ascórbico/metabolismo , Mirtilos Azuis (Planta)/química , Mirtilos Azuis (Planta)/metabolismo , Frutas/química , Frutas/efeitos dos fármacos , Frutas/metabolismo , Glutationa Redutase/metabolismo , Peróxido de Hidrogênio/metabolismo , Lignina/metabolismo , Peroxidase/metabolismo , Superóxido Dismutase/metabolismo
18.
Plant Sci ; 285: 141-150, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203879

RESUMO

Plant tissue brittleness is related to cellular structure and lodging. MED0031 is a mutant identified previously from ethyl methane sulfonate treatment of diploid wheat accession TA2726, showing brittleness in both stem and leaf. In microscopic and histological observations, the mutant was found to have less large vascular bundles per unit area, a thinner sclerenchyma cell wall, and a broader parenchyma, compared with the wild type. The mutated gene, TmBr1, was mapped to a 0.056 cM interval on chromosome 5Am. This gene was cloned using a MapRseq approach that searched the candidate gene through combination of the prior target gene mapping information with SNP calling and discovery of differentially expressed genes from RNA_seq data of the wild type and a BC3F2 bulk showing the mutant phenotype. TmBr1 encodes a COBL protein and a nonsense mutation within the region coding for the conserved COBRA domain caused premature translation termination. Introduction of TmBr1 to Arabidopsis AtCOBL4 mutant rescued the phenotype, demonstrating their functional conservation. Apart from the effect on cellulose content, the TmBr1 mutation might modulate synthesis of noncellulosic polysaccharide pectin as well. Application of the MapRseq approach to isolation of genes present in recombination cold spots and complicated genomes was discussed.


Assuntos
Clonagem Molecular/métodos , Genes de Plantas/genética , Triticum/genética , Parede Celular/metabolismo , Celulose/metabolismo , Mapeamento Cromossômico , Genes de Plantas/fisiologia , Lignina/metabolismo , Microscopia Eletrônica de Varredura , Pectinas/metabolismo , Filogenia , Reação em Cadeia da Polimerase em Tempo Real , Triticum/anatomia & histologia , Triticum/fisiologia
19.
Planta ; 250(2): 395-412, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31236698

RESUMO

MAIN CONCLUSION: Bioethanol from lignocellulosic biomass is a promising step for the future energy requirements. Grass is a potential lignocellulosic biomass which can be utilised for biorefinery-based bioethanol production. Grass biomass is a suitable feedstock for bioethanol production due to its all the year around production, requirement of less fertile land and noninterference with food system. However, the processes involved, i.e. pretreatment, enzymatic hydrolysis and fermentation for bioethanol production from grass biomass, are both time consuming and costly. Developing the grass biomass in planta for enhanced bioethanol production is a promising step for maximum utilisation of this valuable feedstock and, thus, is the focus of the present review. Modern breeding techniques and transgenic processes are attractive methods which can be utilised for development of the feedstock. However, the outcomes are not always predictable and the time period required for obtaining a robust variety is generation dependent. Sophisticated genome editing technologies such as synthetic genetic circuits (SGC) or clustered regularly interspaced short palindromic repeats (CRISPR) systems are advantageous for induction of desired traits/heritable mutations in a foreseeable genome location in the 1st mutant generation. Although, its application in grass biomass for bioethanol is limited, these sophisticated techniques are anticipated to exhibit more flexibility in engineering the expression pattern for qualitative and qualitative traits. Nevertheless, the fundamentals rendered by the genetics of the transgenic crops will remain the basis of such developments for obtaining biorefinery-based bioethanol concepts from grass biomass. Grasses which are abundant and widespread in nature epitomise attractive lignocellulosic feedstocks for bioethanol production. The complexity offered by the grass cell wall in terms of lignin recalcitrance and its binding to polysaccharides forms a barricade for its commercialization as a biofuel feedstock. Inspired by the possibilities for rewiring the genetic makeup of grass biomass for reduced lignin and lignin-polysaccharide linkages along with increase in carbohydrates, innovative approaches for in planta modifications are forging ahead. In this review, we highlight the progress made in the field of transgenic grasses for bioethanol production and focus our understanding on improvements of simple breeding techniques and post-harvest techniques for development in shortening of lignin-carbohydrate and carbohydrate-carbohydrate linkages. Further, we discuss about the designer lignins which are aimed for qualitable lignins and also emphasise on remodelling of polysaccharides and mixed-linkage glucans for enhancing carbohydrate content and in planta saccharification efficiency. As a final point, we discuss the role of synthetic genetic circuits and CRISPR systems in targeted improvement of cell wall components without compromising the plant growth and health. It is anticipated that this review can provide a rational approach towards a better understanding of application of in planta genetic engineering aspects for designing synthetic genetic circuits which can promote grass feedstocks for biorefinery-based bioethanol concepts.


Assuntos
Biocombustíveis , Etanol/metabolismo , Engenharia Genética , Poaceae/genética , Biomassa , Biotecnologia , Fermentação , Hidrólise , Lignina/metabolismo , Melhoramento Vegetal , Plantas Geneticamente Modificadas , Poaceae/crescimento & desenvolvimento , Poaceae/metabolismo , Polissacarídeos/metabolismo , Desenvolvimento Sustentável
20.
J Agric Food Chem ; 67(25): 6950-6961, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31150582

RESUMO

p-Quinone methide (QM) is formed as an intermediate during lignin biosynthesis. The aromatization of the QM by the attack of a nucleophile at the α-position of its side chain generates a phenolic hydroxy group in a growing polymer and creates stereoisomeric forms in the side chain. A series of ß-O-4-aryl ether QMs was reacted with water at 25 °C to replicate the formation of p-hydroxyphenyl (H) and guaiacyl (G) ß-O-4 structures in plant cell walls. Water addition occurred in 3-methoxy-substituted QMs (G-type QMs) with half-lives ( t1/2) between 13 and 15 min, at pH 7, in 50% water solution (dioxane-water, 1:1). The rate increased as the water concentration increased to 99% ( t1/2, 1.2-1.4 min). Similar solvent effects were observed for more reactive nonsubstituted QMs (H-type QMs with t1/2 of <1 min). Consequently, t1/2 of the H-type QMs was shorter than that of the G-type QMs under every solvent condition. Upon increasing the water concentration, the variation in the erythro/ threo ratios of the four dimeric ß-O-4 products increased. Interestingly, the effect of pH on the stereopreference, which was observed in 50% water solution, was small and became imperceptible as the water concentration increased to 99%, suggesting that the effect of the solvent, as well as the effect of the pH, plays an important role in understanding the reaction conditions in cell walls during lignin biosynthesis. The threo isomer was preferentially formed in the four dimeric ß-O-4 structures, which is inconsistent with the structural features of compression wood lignin rich in H-units. However, the erythro-selective formation was attained in an H-type QM at every pH studied (pH 3.5-7) by introducing a biphenyl structure into the ß-etherified ring moiety.


Assuntos
Indolquinonas/química , Lignina/química , Lignina/metabolismo , Modelos Químicos , Estrutura Molecular , Solventes/química , Estereoisomerismo , Água/química , Madeira/metabolismo
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