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1.
Food Chem ; 337: 127745, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32795855

RESUMO

Microalgae are a precious source of polyunsaturated fatty acids (PUFA), however extraction is difficult due to the peculiar microalgae cell structure. Here we describe a new method based on the application of chitosan nanoaggregates as CO2 responsive emulsifier, used to promote the swelling of algae cell wall and the formation of a large oil - ethanol interphase area during the ethanolysis. Tests were carried out with Pseudokirchneriella subcapitata and Nannochloropsis sp. at different biomass/ethanol/chitosan ratios. CO2 was added to trigger demulsification to promote an easy recovery of the lipid fraction. The highest yields in PUFA were obtained with Nannochloropsis sp. (207.9 mg/g of oil) using 0.4% wt of chitosan and 1:10 biomass:ethanol ratio; 43.6 mg/g of linolenic acid were obtained from Pseudokirchneriella subcapitata. Overall, because the method employs ethanol, a generally recognized as safe (GRAS) solvent, and food grade additives, it is suited for the preparation of PUFA supplements.


Assuntos
Quitosana/farmacologia , Ácidos Graxos Ômega-3/metabolismo , Microalgas/efeitos dos fármacos , Microalgas/metabolismo , Biomassa , Suplementos Nutricionais , Esterificação/efeitos dos fármacos , Etanol/farmacologia
2.
Waste Manag ; 118: 626-636, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33011540

RESUMO

Due to its environment-friendly and replenishable characteristics, biodiesel has the potential to substitute fossil fuels as an alternative source of energy. Although biodiesel has many benefits to offer, manufacturing biodiesel on an industrial scale is uneconomical as a high cost of feedstock is required. A novel sulfonated and magnetic catalyst synthesised from a palm kernel shell (PMB-SO3H) was first introduced in this study for methyl ester or biodiesel production to reduce capital costs. The wasted palm kernel shell (PKS) biochar impregnated with ferrite Fe3O4 was synthesised with concentrated sulphuric acid through the sulfonation process. The SEM, EDX, FTIR, VSM and TGA characterization of the catalysts were presented. Then, the optimisation of biodiesel synthesis was catalysed by PMB-SO3H via the Response Surface Methodology (RSM). It was found that the maximum biodiesel yield of 90.2% was achieved under these optimum operating conditions: 65 °C, 102 min, methanol to oil ratio of 13:1 and the catalyst loading of 3.66 wt%. Overall, PMB-SO3H demonstrated acceptable catalysing capability on its first cycle, which subsequently showed a reduction of the reusability performance after 4 cycles. An important practical implication is that PMB-SO3H can be established as a promising heterogeneous catalyst by incorporating an iron layer which can substantially improve the catalyst separation performance in biodiesel production.


Assuntos
Biocombustíveis , Óleos Vegetais , Carvão Vegetal , Esterificação , Fenômenos Magnéticos
3.
J Oleo Sci ; 69(10): 1281-1285, 2020 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-32908100

RESUMO

In this study two different strategy were followed to obtain a D-fructose-oleic acid ester. One of the strategies has been well established enzymatic synthesis of an ester bond. The other strategy excluded the biocatalyst and only used a mixture of two organic solvents as the reaction media, 2-methyl-2-butanol / dimethyl sulfoxide or tert-butanol / dimethyl sulfoxide for the production of D-fructose-oleic acid ester. Ester products obtained were characterised by using FT-IR, NMR, by MS. Product yield was also assessed by HPLC. Results of structural analyses and yield measurement indicated that two approaches produced almost identical ester products.


Assuntos
Dimetil Sulfóxido/química , Ésteres/síntese química , Frutose/síntese química , Ácido Oleico/síntese química , Pentanóis/química , terc-Butil Álcool/química , Animais , Biocatálise , Células Cultivadas , Cromatografia Líquida de Alta Pressão , Esterificação , Ésteres/química , Ésteres/toxicidade , Frutose/química , Frutose/toxicidade , Espectroscopia de Ressonância Magnética , Espectrometria de Massas , Ácido Oleico/química , Ácido Oleico/toxicidade , Espectroscopia de Infravermelho com Transformada de Fourier
4.
Environ Pollut ; 266(Pt 2): 115377, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32798907

RESUMO

As demand of proteins from meats has significantly increased with economy growth, the population of livestock proliferates. Thus, heavy amount of livestock byproducts released from livestock industries will become more problematic if they are handled in an unsatisfactory manner. In this study, swine manure (SM) waste was directly valorized to be used as a reaction catalyst for biodiesel production. Pyrolysis was adapted to produce swine manure biochars at 500 (SMB@500) and 650 °C (SMB@650), and the materials were used for conversion of waste cooking oil into biodiesels (i.e., fatty acid methyl esters: FAMEs). The properties of SMBs and resulting pyrolytic gases (i.e., H2, CO, and C1-2 hydrocarbons (HCs)) and liquids during pyrolysis were also characterized. SMBs used in this study included a large quantity of metallic contents that significantly contributed to the rapid reaction for biodiesel production. In detail, SMB@500 and SMB@650 showed higher than 96% of FAME yield at 305 and 210 °C of reaction temperature, while non-catalytic reaction using SiO2 showed similar FAME yield at 330 °C. Thus, this work offers a sustainable way to recycle organic and inorganic materials in livestock manures for energy (biodiesel, pyrolytic oil, H2, and C1-2 HCs) production.


Assuntos
Biocombustíveis , Esterco , Animais , Catálise , Carvão Vegetal , Culinária , Esterificação , Dióxido de Silício , Suínos
5.
J Oleo Sci ; 69(9): 1043-1049, 2020 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-32788510

RESUMO

The 2-ethylhexyl stearate is used as a bio-lubricant in various cosmetic products. The present study is focused on the biocatalyzed esterification of 2-ethylhexanol and stearic acid to form 2-ethylhexyl stearate catalyzed by Fermase CALB 10000 in the presence of ultrasound treatment. The maximum conversion (95.87%) was obtained at molar ratio of 2-ethylhexanol to stearic acid 2:1, enzyme amount of 2 % (w/w), power 80 W, duty cycle 50 % and temperature 50°C in comparatively short reaction time (3 h) in the presence of Fermase as a catalyst. At optimum conditions, it is observed that in the presence of ultrasound; the reaction time minimizes up to 4 h as compared to mechanical stirring method (7 h). The physiochemical properties for the 2-ethylhexyl palmitate were also evaluated.


Assuntos
Hexanóis/química , Estearatos/síntese química , Ondas Ultrassônicas , Biocatálise , Fenômenos Químicos , Enzimas Imobilizadas/química , Esterificação , Estearatos/química , Ácidos Esteáricos/química , Temperatura , Fatores de Tempo
6.
Bioresour Technol ; 317: 124032, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32829119

RESUMO

This study demonstrates that the biodiesel (BD) from swine manure (SM) could be a promising way for large scale generation of biofuel. Also, the economic and environmental benefits of SM derived BD were evaluated. Transesterification of lipid contents extracted from the collected SM had low BD yield (14.2 wt%) using H2SO4 catalyst due to high acid value and impurities. However, thermo-chemical non-catalytic transesterification with a porous material showed 94.7 wt% yield of BD from the lipid in SM. Considering the current population of swine, the annual production of BD from SM was estimated. The SM derived BD could cover 19.7 and 46.8 wt% of BD currently produced in both Korea and the USA with the economic benefits of up to $96 million and $2.1 billion, respectively. The proposed approach also can save vast arable lands needed to cultivate oil-bearing feedstocks for BD production.


Assuntos
Biocombustíveis , Esterco , Animais , Catálise , Esterificação , República da Coreia , Suínos
7.
Bioresour Technol ; 315: 123852, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32712516

RESUMO

The present research work is aimed at reducing the consumption of reactants by process optimization and economic analysis of large-scale commercial plant using techno-economic analysis. The statistical optimization of biodiesel production from Calophyllum inophyllum oil using Zn doped CaO nanocatalyst was used to optimize the conversion efficiency and green chemistry value. The environmental studies on transesterification reaction were done using green chemistry parameters like carbon efficiency, atom economy, reaction mass efficiency, stoichiometric factor and environmental factor. The biodiesel conversion 91.95% was achieved when maintaining the methanol to oil ratio 9.66:1, concentration of catalyst 5% (w/v), time 81.31 min and temperature 56.71 °C with green chemistry value of 0.873. Techno-economic analysis of biodiesel production from Calophyllum inophyllum oil was executed used optimized lab-scale data. The techno-economic analysis of 21 million kg/year biodiesel production plant was investigated. The annual biodiesel revenue of 15,224,000 $/yr and the payback period was about 1.15 years.


Assuntos
Calophyllum , Biocombustíveis , Catálise , Esterificação , Óleos Vegetais
8.
Food Chem ; 332: 127366, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32619940

RESUMO

High methyl-esterified citrus pectin (HMCP) molecules could be self-assembled into micelles in water. The morphology of HMCP micelles in water was irregular spheres, long rods, and arc-shaped. Most of HMCP molecules cross-linked with HMCP micelles in the presence of calcium chloride and increased the range of size distribution of HMCP micelles. A little number of HMCP molecules cross-linked with each other to form 80 nn ~ 200 nm microgel particles. Calcium chloride could improve HMCP emulsification when its concentration was more than 70 mmol/L. HMCP micelles could be adsorbed on the surface of emulsion droplets. The emulsion prepared with HMCP and calcium chloride was similar to the Pickering emulsion.


Assuntos
Cloreto de Cálcio/química , Pectinas/química , Emulsões , Esterificação , Metilação , Micelas , Água/química
9.
Biochim Biophys Acta Rev Cancer ; 1874(1): 188394, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32698040

RESUMO

Cholesterol and its metabolites (precursors and derivatives) play an important role in cancer. In recent years, numerous studies have reported the functions of cholesterol metabolism in the regulation of tumor biological processes, especially oncogenic signaling pathways, ferroptosis, and tumor microenvironment. Preclinical studies have over the years indicated the inhibitory effects of blocking cholesterol synthesis and uptake on tumor formation and growth. Besides, some new cholesterol metabolic molecules such as SOAT1, SQLE, and NPC1 have recently emerged as promising drug targets for cancer treatment. Here, we systematically review the roles of cholesterol and its metabolites, and the latest advances in cancer therapy targeting cholesterol metabolism.


Assuntos
Colesterol/metabolismo , Redes e Vias Metabólicas , Neoplasias/metabolismo , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Transporte Biológico/efeitos dos fármacos , Esterificação/efeitos dos fármacos , Ferroptose , Humanos , Redes e Vias Metabólicas/efeitos dos fármacos , Redes e Vias Metabólicas/genética , Neoplasias/tratamento farmacológico , Neoplasias/imunologia , Neoplasias/patologia , Oxisteróis/metabolismo , Transdução de Sinais
10.
J Oleo Sci ; 69(7): 693-701, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612019

RESUMO

Fatty acid sugar esters are non-ionic surfactant active agents with excellent performance and many uses. This work is devoted to the synthesis of sugar esters by the esterification reaction of sugar with mixed carboxylicpalmitic anhydrides using resin Amberlyst-15 as heterogeneous acid catalyst. These anhydrides should be stable and react as acylating agents. Influence of different reaction parameters, such as the molar ratio (sucrose/anhydride), the type of solvent and the reaction time on the yield of the esterification reaction were studied. The esterification reaction of sucrose with mixed palmitic benzoic anhydride leads to a mixture of sucrose esters of palmitic acid with a good percentage of conversion. The mixed anhydride was both reactive and selective for the preparation of fatty acid ester.


Assuntos
Benzoatos/química , Ácidos Carboxílicos/química , Técnicas de Química Sintética/métodos , Ésteres/síntese química , Ácidos Graxos/síntese química , Ácido Palmítico/química , Sacarose/síntese química , Acilação , Catálise , Esterificação , Solventes , Estirenos , Tensoativos/síntese química , Fatores de Tempo
11.
J Oleo Sci ; 69(7): 727-735, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612022

RESUMO

Petroleum based phthalate plasticizers encounter enormous claims to prohibit their production due to their harmful health impacts when they are mixed with plastics. That is why efforts are being done to find safer natural alternatives. We have investigated the reaction kinetics of the esterification epoxidation of oleic acid and 2-ethylhexanol in the presence of hydrogen peroxide catalyzed using Candida antarctica lipase (Novozym 435, Novozymes, Kobenhavn, Denmark). The product of this reaction is epoxidized 2-ethylhexyl oleate, a non-phthalate green plasticizer. The kinetic model for this reaction follows a multi-substrate PingPong Bi-Bi mechanism with competitive inhibition by the alcohol. The reaction's kinetic parameters were found to be 0.76 M, 0.37 M, 0.08 M, and 37.20 mM/min for Michalis-Menten constant for oleic acid (Kmo), Michalis-Menten constant for alcohol (Kma), alcohol inhibition constant (Kia), and maximum reaction velocity (Vmax), respectively. Then the Gibbs function analysis of the transition state based on the Arrhenius and Eyring equations was carried out. The internal diffusional limitations were found to be negligible as the effectiveness factor took the value of almost unity. While the external mass transfer resistance had no effect on the reaction due to operating at relatively high agitation speed and high temperature. This investigation confirms that this reaction was only kinetically controlled.


Assuntos
Técnicas de Química Sintética , Lipase/química , Ácidos Ftálicos , Plastificantes/síntese química , Aldeídos/química , Candida/enzimologia , Catálise , Esterificação , Cinética , Ácido Oleico/química , Fenômenos de Química Orgânica
12.
J Oleo Sci ; 69(7): 737-742, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32612023

RESUMO

Esterification of D-glucose with oleic- and palmitic acids were carried out in the absence and presence of a biocatalyst, Candida antarctica lipase. The reaction medium was a mixture of dimethyl sulphoxide and tert-butanol (1:4, v/v). The reaction products were analysed by FTIR, 1H-NMR and 13C-NMR, HSQC, and by ESI-MS. Results indicated that the ester products formed were 6-O-glucose oleate and 6-O-glucose palmitate both in the absence and in the presence of the biocatalyst, with yields above 90%.


Assuntos
Biocatálise , Ésteres/síntese química , Glucose/química , Ácido Oleico/síntese química , Ácidos Oleicos/química , Palmitatos/síntese química , Ácidos Palmíticos/química , terc-Butil Álcool/química , Dimetil Sulfóxido/química , Esterificação , Proteínas Fúngicas/química , Lipase/química
13.
J Oleo Sci ; 69(8): 859-864, 2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32641607

RESUMO

Chicken skin -a poultry meat industries waste- has been used in this work as a source for the production of pure free fatty acids. Chicken skin fat was extracted using dry rendering method. Physical and chemical parameters of that fat were determined. Also, its fatty acids composition has been identified by GC-MS after its esterification as oleic, palmitic, linoleic, stearic, myristic, lauric, linolenic, behenic, arachidonic, arachidic, palmitoleic, and paullinic acids, and others as traces. The extracted fat was then hydrolyzed into mixture of free fatty acids and glycerol, the free fatty acid mixture was separated, then it was cooled in order to separate saturated and unsaturated fatty acids from each other. Oleic, Palmitic, Linoleic and Stearic Acids were extracted individually in pure form using supercritical CO2 extractor. Moreover, oleic, linoleic, palmitoleic, linolenic, and paullinic acids were extracted individually in pure form using cooling centrifuge sigma 3-18KS. All of the separated individual fatty acids were confirmed according to their melting point, GC-MS after esterification, elemental analysis and mass spectrometry (ms) of the corresponding methyl ester in order to detect the corresponding molecular ion peak. Therefore, these new two methods could afford the very expensive pure fatty acids with a low cast.


Assuntos
Centrifugação/métodos , Galinhas , Ácidos Graxos não Esterificados/isolamento & purificação , Produtos Avícolas , Pele/química , Extração em Fase Sólida/métodos , Animais , Temperatura Baixa , Esterificação , Gorduras Insaturadas/isolamento & purificação , Ácidos Graxos/isolamento & purificação , Ácidos Graxos não Esterificados/análise , Cromatografia Gasosa-Espectrometria de Massas , Extração em Fase Sólida/instrumentação , Temperatura de Transição
14.
J Oleo Sci ; 69(8): 907-912, 2020 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-32641616

RESUMO

D-ribose-oleic acid esters were produced with or without a biocatalyst, using in the same organic media, dimethyl sulfoxide (DMSO): tert-butanol (TBU) or 2-methyl-2-butanol (2M2B). The yield of the ester product was above 90% in both of the reactions. The biocatalyst used was lipase B of Candida antarctica. Molecular characterization was performed by using all the analytical methods available: IR, 1H-NMR and 13C-NMR, HSQC, and ESI-MS.


Assuntos
Biocatálise , Ésteres/síntese química , Proteínas Fúngicas/química , Lipase/química , Ácidos Oleicos/síntese química , Ribose/síntese química , Dimetil Sulfóxido/química , Esterificação , Ésteres/química , Ácidos Oleicos/química , Pentanóis/química , Ribose/química , terc-Butil Álcool/química
15.
Environ Sci Pollut Res Int ; 27(29): 36450-36462, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32562223

RESUMO

The present investigation aims to develop simultaneous extraction and conversion of inedible Madhuca longifolia seed oil into biodiesel by one-step acid-catalyzed in situ transesterification/reactive extraction process. Six different types of pretreatment were used to assess maximum yield of biodiesel. The maximum yield of 96% biodiesel was acquired with ultrasonic pretreatment at 1% moisture content, 0.61 mm seed grain size, 55 °C temperature, 400 rpm stirring speed, 15 wt% catalyst (H2SO4) concentration, and with 1:35 seed oil to methanol ratio in a time period of 180 min. This reaction kinetics precedes first order also the finest value of rate constant and activation energy were calculated as 0.003 min-1 and 14.840 kJ mol-1. The thermodynamic energy properties ΔG, ΔH, and ΔS are computed as 96457.172 J/mol, 12121.812 J/mol K, and - 257.12 J/mol K correspondingly. The enumerated outcome illustrates a heat absorb non-spontaneous/endergonic and endothermal reaction. The result of proposed work unveils ultrasonic pretreatment escalates the biodiesel efficiency and reactive extraction exemplifies the clean, cost-effective single-step approach for production of biodiesel from non-edible sources.


Assuntos
Biocombustíveis , Madhuca , Catálise , Esterificação , Cinética , Óleos Vegetais , Sementes , Termodinâmica
16.
Food Chem ; 331: 127200, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32554308

RESUMO

In this work, synthesis of phytosteryl ornithine ester hydrochloride was studied for the first time using an intermediate phytosteryl N,N'-bis[tert-butoloxycarbonyl(BOC)]-ornithine ester. This method also involved esterification of phytosterols with N,N'-bis(BOC)-ornithine and deprotection. The maximum yield was 90% and deprotection of BOC group was more than 99% using the HCl/ethyl acetate method. As a result, thermal stability and water solubility as well as emulsifying activity and stability of phytosterols were improved through coupling with ornithine, which is favorable for their application in water-based food systems. We also observed increased bioaccessibility of phytosteryl ornithine hydrochloride (4.5%) and 65% of phytosteryl ornithine hydrochloride was hydrolyzed in vitro. These results indicated that ornithine phytosteryl ester hydrochloride can reduce dissolution capacity of cholesterol in vitro, representing improved cholesterol-reducing activity, which will further expand the applications of phytosteryl ornithine ester hydrochloride.


Assuntos
Anticolesterolemiantes/química , Acetatos/química , Anticolesterolemiantes/síntese química , Anticolesterolemiantes/farmacocinética , Disponibilidade Biológica , Colesterol/metabolismo , Digestão , Emulsificantes/química , Esterificação , Humanos , Hidrólise , Espectroscopia de Ressonância Magnética , Ornitina/química , Fitosteróis/síntese química , Solubilidade , Óleo de Soja/química , Espectroscopia de Infravermelho com Transformada de Fourier , Água
17.
Bioresour Technol ; 312: 123586, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32485612

RESUMO

The aim of this work was to study the conversion of lignocellulose into biochar and furfural through boron complexation and esterification reaction. Boric acid was used to modify lignocellulose to obtain a high biochar yield boron-lignocellulosic material through complexation and esterification reactions. Furthermore, clean furfural was obtained as the gas products of boron-lignocellulosic materials pyrolysis. The structures of the boron-lignocellulosic materials were characterized, and their compound principle was revealed. Boric acid treatments increased the initial thermal degradation temperature of lignocellulose and promoted the formation of biochar and furfural. The biochar yield rate increased by 135.7% from 18.6 to 42.9% at 600 ℃ after 5% boric acid solution treatment. Compared with pure lignocellulose, cleaner and higher quantities of furfural were obtained from boron-lignocellulose pyrolysis. Finally, the possible chemical decomposition pathways of boron-lignocellulosic materials were identified. This study provides a new perspective on the thermochemical conversion of lignocellulose to furfural and biochar.


Assuntos
Boro , Furaldeído , Carvão Vegetal , Esterificação , Lignina
18.
Bioresour Technol ; 312: 123607, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32504947

RESUMO

Switchable solvent N, N, N', N'-tetraethyl-1,3-propanediamine (TEPDA) was proposed to extract lipids from wet Nannochloropsis oceanica with a 5% higher extraction efficiency than chloroform-methanol. It was found that TEPDA acted mainly as an organic solvent to soften and dissolve lipids, while a small amount of TEPDA was dissociated into tertiary amine ion, i.e.,(C2H5)2N-(CH2)3-NH+(C2H5)2. This cation acted as a surfactant to promote cell disruption and lipid separation. With moisture increasing from 0 to 84 wt%, more TEPDA was dissociated into cationic surfactant to induce local rearrangement of phospholipid bilayers in cell membranes through electrostatic interaction, resulting in the fractal dimension of disrupted cells increased from 1.49 to 1.66. Accordingly, the yield of fatty acid methyl ester (FAME) through transesterification of lipids extracted with TEPDA increased by 9%, while FAME yield from lipids extracted with chloroform and n-hexane decreased by 41% and 65%, respectively.


Assuntos
Microalgas , Biocombustíveis , Biomassa , Esterificação , Lipídeos , Solventes , Tensoativos
19.
J Biosci Bioeng ; 130(4): 397-401, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32586661

RESUMO

In situ transesterification of oleaginous microbes with short chain alcohol has been developed as a renewable process for the production of biodiesel. Dry biomass is often a requisite for the process to avoid the adverse effect of water on the productivity. As a consequence, large amount of energy consumption is required for prior biomass drying. In this study, the wet biomass of Rhodotorula glutinis, an oleaginous yeast, was used directly in in situ transesterification without biomass drying. The reaction conditions were optimized for the production of fatty acid methyl esters (FAME) and the effects of adding different surfactants were also studied. The highest FAME yield of 110% was achieved with a methanol loading of 1:100 at 90°C for 8 h as catalyzed by 0.36 M H2SO4, and the FAME content was 97%, which meets the 96.5% specified in both European biodiesel standards and Taiwanese biodiesel standards. The addition of 50 mM 3-(N,N-dimethylmyristylammonio)propanesulfonate (3-DMAPS, a zwitterionic surfactant) improved the FAME yield from 69% to 83%, which was obtained with a low methanol loading of 1:10 at 90°C for 10 h. Hence, the production of FAME with wet biomass under optimized reaction conditions was as effective as that with the dry form. This clearly indicates that using wet R. glutinis as the feedstock is feasible for the production of biodiesel by in situ transesterification.


Assuntos
Biomassa , Rhodotorula/química , Tensoativos/química , Biocombustíveis , Catálise , Esterificação , Ácidos Graxos/química , Metanol/química , Água/química
20.
PLoS One ; 15(5): e0227591, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32433654

RESUMO

Plants emit high rates of methanol (meOH), generally assumed to derive from pectin demethylation, and this increases during abiotic stress. In contrast, less is known about the emission and source of acetic acid (AA). In this study, Populus trichocarpa (California poplar) leaves in different developmental stages were desiccated and quantified for total meOH and AA emissions together with bulk cell wall acetylation and methylation content. While young leaves showed high emissions of meOH (140 µmol m-2) and AA (42 µmol m-2), emissions were reduced in mature (meOH: 69%, AA: 60%) and old (meOH: 83%, AA: 76%) leaves. In contrast, the ratio of AA/meOH emissions increased with leaf development (young: 35%, mature: 43%, old: 82%), mimicking the pattern of O-acetyl/methyl ester ratios of leaf bulk cell walls (young: 35%, mature: 38%, old: 51%), which is driven by an increase in O-acetyl and decrease in methyl ester content with age. The results are consistent with meOH and AA emission sources from cell wall de-esterification, with young expanding tissues producing highly methylated pectin that is progressively demethyl-esterified. We highlight the quantification of AA/meOH emission ratios as a potential tool for rapid phenotype screening of structural carbohydrate esterification patterns.


Assuntos
Ácido Acético/metabolismo , Parede Celular/metabolismo , Metanol/metabolismo , Folhas de Planta/metabolismo , Acetilação , Atmosfera , Hidrolases de Éster Carboxílico/metabolismo , Esterificação , Metilação , Pectinas/metabolismo , Folhas de Planta/crescimento & desenvolvimento , Proteínas de Plantas/genética , Populus/efeitos dos fármacos , Populus/crescimento & desenvolvimento , Populus/metabolismo , Estresse Fisiológico/genética
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