Functional materials synthesized from bio-based building blocks are fascinating and challenging in the fields of chemistry and materials science.Herein,we present a versatile strategy for synthesizing bio-based stimul...Functional materials synthesized from bio-based building blocks are fascinating and challenging in the fields of chemistry and materials science.Herein,we present a versatile strategy for synthesizing bio-based stimulus-responsive polymers derived from itaconic acid(IA).Bearing an azobenzene-containing side chain,the IA-based epoxy polymer exhibited both photoresponsiveness and acid/base-stimulus responsiveness.With controllable manipulation of the stress field of the wrinkling IA-polymer film via the stress relaxation effect resulting from the reversible cis-trans isomerization of the azobenzene moieties or solvent-induced swelling of the film,various tailor-made patterned wrinkling surfaces were conveniently fabricated.More importantly,the azobenzene protonation/deprotonation yields a reversible visual color transformation between pale yellow and purple in the film,which allows these IA-based polymer-coated surfaces to be utilized as rewritable information storage media.Various elegant pattern information can be acid-printed and base-erased(within 10 s)for multiple cycles and legible for over one day under laboratory conditions.Notably,the aforementioned dual-stimulus responsiveness of the IA-based polymer film enables its surface to be applied in information encryption.This study not only paves a new avenue for the convenient fabrication of stimulus-responsive surfaces but also sheds light on the development of functional polymers through green engineering.展开更多
Methacrylic acid,an important organic chemical,is commercially manufactured starting from fossil feedstock.The decarboxylation of itaconic acid derived for biomass is a green route to the synthesis of methacrylic acid...Methacrylic acid,an important organic chemical,is commercially manufactured starting from fossil feedstock.The decarboxylation of itaconic acid derived for biomass is a green route to the synthesis of methacrylic acid.In view of the problems existing in the researches on this route such as use of noble metal catalyst,harsh reaction conditions and low desired-product yield,we prepared a series of hydroxyapatite catalysts with different Ca/P molar ratios and evaluated their catalytic performance.The results showed that the hydroxyapatite catalyst with a Ca/P molar ratio of 1.58 had the best catalytic activity.The highest yield of MAA up to 61.2%was achieved with basically complete conversion of itaconic acid under the suitable reaction conditions of 1 equivalent of NaOH,2 MPa of N_(2),250℃,and 2 h.On this basis,a reaction network for the decarboxylation of itaconic acid to methacrylic acid catalyzed by hydroxyapatite was established.With the aid of catalyst characterization using X-ray powder diffraction,NH3/CO2 temperature-programmed desorption,N_(2)physisorption,inductively coupled plasma optical emission spectrometry,and scanning electron microscopy,we found that the distribution of surface acid sites and basic sites,crystal growth orientation,texture properties and morphology of hydroxyapatite varied with the Ca/P molar ratio.Furthermore,the change of the crystal growth orientation and its influence on the surface acidity and alkalinity were clarified.展开更多
The synthesis of methacrylic acid from biomass-derived itaconic acid is a green route,for it can get rid of the dependence on fossil resource.In order to solve the problems on this route such as use of a preciousmetal...The synthesis of methacrylic acid from biomass-derived itaconic acid is a green route,for it can get rid of the dependence on fossil resource.In order to solve the problems on this route such as use of a preciousmetal catalyst and a corrosive homogeneous alkali,we prepared a series of hydroxyapatite catalysts by an ionic liquid-assisted hydrothermal method and evaluated their catalytic performance.The results showed that the ionic liquid[Bmim]BF_(4) can affect the crystal growth of hydroxyapatite,provide fluoride ion for fluorination of hydroxyapatite,and adjust the surface acidity and basicity,morphology,textural properties,crystallinity,and composition of hydroxyapatite.The[Bmim]BF4 dosage and hydrothermal temperature can affect the fluoride ion concentration in the hydrothermal system,thus changing the degree of fluoridation of hydroxyapatite.High fluoride-ion concentration can lead to the formation of CaF_(2) and thus significantly decrease the catalytic performance of hydroxyapatite.The hydrothermal time mainly affects the growth of hydroxyapatite crystals on the c axis,leading to different catalytic performance.The suitable conditions for the preparation of this fluoridized hydroxyapatite are as follows:a mass ratio of[Bmim]BF4 to calcium salt=0.2:1,a hydrothermal time of 12 h,and a hydrothermal temperature of 130℃.A maximal methacrylic acid yield of 54.7%was obtained using the fluoridized hydroxyapatite under relatively mild reaction conditions(250℃ and 2 MPa of N_(2))in the absence of a precious-metal catalyst and a corrosive homogeneous alkali.展开更多
The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while th...The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.展开更多
With N-vinyl-2-pyrrolidone (NVP) and itaconic acid(IA), poly(N-vinyl-2-pyrrolidone/itaconic acid)[P(NVP/IA)] hydrogel was synthesized by free radical solution polymerization. The structure of this (P(NVP/IA)) was char...With N-vinyl-2-pyrrolidone (NVP) and itaconic acid(IA), poly(N-vinyl-2-pyrrolidone/itaconic acid)[P(NVP/IA)] hydrogel was synthesized by free radical solution polymerization. The structure of this (P(NVP/IA)) was characterized by IR. Effects of concentration of itaconic acid, amount of cross-link agent, N,N′-methylene-bis-acrylamide, reaction temperature, and time on properties of swelling ratio(SR) of the hydrogel were investigated.The results show that the best swelling property of the hydrogel is obtained at 50 ℃ and 1.5 h. pH sensitivity increases as the concentration of itaconic acid in the hydrogel system increases. Swelling ratio of the hydrogel decreases as the amount of cross-link agent increases.展开更多
An improved process of hydrolysis of corn starch was adopted in the production of itaconic acid （IA）, the aim was to decrease the unfermentable reducing sugar （RS） in the medium from the beginning of the fermentat...An improved process of hydrolysis of corn starch was adopted in the production of itaconic acid （IA）, the aim was to decrease the unfermentable reducing sugar （RS） in the medium from the beginning of the fermentation and to increase the crystallization efficiency of IA from the fermentation broth. The glucose （GS） syrups saccharified by several combinations of glucoamylase and pullulanase were investigated and used as the carbohydrate source of the fermentation medium for the spore-initiated submerged fermentations experiments. Compared with the conventional process （with pullulanase controlled）, the improved process decreased th.e RS residue in the fermentation broth from 3.01g/L to 1.35g/L and from 4.25g/L to 3.25g/L when the original RS of the medium were 100 and 120g/L, respectively. The crystallization efficiency of IA increased from 65% to 78.8% and from 69.58% to 82.81% with the original RS being 100 and 120g/L, respectively.展开更多
This review summarizes the metabolic origin,pharmacological activities,and regulatory mechanisms of itaconic acid at the transcriptional,post-translational modification,and metabolic levels.Its potential application i...This review summarizes the metabolic origin,pharmacological activities,and regulatory mechanisms of itaconic acid at the transcriptional,post-translational modification,and metabolic levels.Its potential application in various diseases is also discussed,providing a theoretical basis for the development of itaconic acid as an anti-inflammatory immunomodulatory agent.展开更多
Itaconic acid(ITA)is an unsaturated organic acid used in industrial production due to its versatility as a polymer building block.Engineering microbial cell factories for ITA biosynthesis from cost-effective and renew...Itaconic acid(ITA)is an unsaturated organic acid used in industrial production due to its versatility as a polymer building block.Engineering microbial cell factories for ITA biosynthesis from cost-effective and renewable raw materials has gained significant attention.Here,we performed combinatorial engineering using Saccharomyces cerevisiae to improve ITA production.First,exogenous cis-aconitic acid decarboxylase(CAD)was integrated into S.cerevisiae to construct the ITA-producing chassis.Then,the rate-limiting step was eliminated by changing the promoter that drives CAD expression to optimize ITA synthesis.A mitochondrial cis-aconitate transporter MTTA was also expressed to facilitate the transport of precursor,which resulted in an ITA titer of 244 mg/L.Furthermore,with overexpression of truncated citrate synthase tCIT2,an increased titer of 409 mg/L was obtained.Finally,the transport protein Qdr3 was overexpressed to enhance the export of ITA,resulting in a production of 578 mg/L in shake flask.In a 5-L bioreactor,the ITA titer reached 1.2 g/L,representing the highest reported level in S.cerevisiae.Overall,an advanced recombinant yeast strain was constructed for the efficient production of ITA via combinatorial metabolic engineering.展开更多
A phosphorus-containing bio-based epoxy resin(EADI)was synthesized from itaconic acid(IA)and 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide(DOPO).As a matrix,its cured epoxy network with methyl hexahydrophthalic a...A phosphorus-containing bio-based epoxy resin(EADI)was synthesized from itaconic acid(IA)and 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide(DOPO).As a matrix,its cured epoxy network with methyl hexahydrophthalic anhydride(MHHPA)as the curing agent showed comparable glass-transition temperature and mechanical properties to diglycidyl ether in a bisphenol A(DGEBA)system as well as good flame retardancy with UL94 V-0 grade during a vertical burning test.As a reactive flame retardant,its flame-resistant effect on DGEBA/MHHPA system as well as its influence on the curing behavior and the thermal and mechanical properties of the modified epoxy resin were investigated.Results showed that after the introduction of EADI,not only were the flame retardancy determined by vertical burning test,LOI measurement,and thermogravimetric analysis significantly improved,but also the curing reactivity,glass transition temperature(T g),initial degradation temperature for 5%weight loss(T d(5%)),and flexural modulus of the cured system improved as well.EADI has great potential to be used as a green flame retardant in epoxy resin systems.展开更多
Itaconic acid(ITA),an effective alternative fossil fuel,derives from the bypass pathway of the tricarboxylic acid(TCA)cycle.Therefore,the imbalance of metabolic flux between TCA cycle and ITA biosynthetic pathway seri...Itaconic acid(ITA),an effective alternative fossil fuel,derives from the bypass pathway of the tricarboxylic acid(TCA)cycle.Therefore,the imbalance of metabolic flux between TCA cycle and ITA biosynthetic pathway seriously limits the production of ITA.The optimization of flux distribution between biomass and production has the potential to the productivity of ITA.Based on the previously constructed strain Escherichia coli MG1655Δ1-SAS-3(ITA titer:1.87 g/L),a CRISPRi-mediated self-inducible system(CiMS),which contained a responsive module based on the ITA biosensor YpItcR/Pccl and a regulative CRISPRi-mediated interferential module,was developed to regulate the flux of the TCA cycle and to enhance the capacity of the strain to produce ITA.First,a higher ITA-yielding strain,Δ4-Prmd-SAS-3(ITA titer:3.20 g/L),derived fromΔ1-SAS-3,was constructed by replacing the promoter PJ23100,for the expression of ITA synthesis genes,with Prmd and knocking out the three bypass genes poxB,pflB,and ldhA.Subsequently,the CiMS was used to inhibit the expression of key genes icd,pykA,and sucCD to dynamically balance the metabolic flux between TCA cycle and ITA biosynthetic pathway during the ITA production stage.The constructed strainΔ4-Prmd-SAS-3 under the dynamic regulation of the CiMS,showed a 23%increase in the ITA titer,which reached 3.93 g/L.This study indicated that CiMS was a practical strategy to dynamically and precisely regulated the metabolic flux in microbial cell factories.展开更多
Itaconic acid(IA)is a precursor of various chemicals,which has been on the US Department of Energy’s list of the top 12 platform chemicals that can potentially be produced from biomass.The IA is mainly produced throu...Itaconic acid(IA)is a precursor of various chemicals,which has been on the US Department of Energy’s list of the top 12 platform chemicals that can potentially be produced from biomass.The IA is mainly produced through a bio-fermentation method with sugar as raw material.However,the high cost and low yield restrict the industrial application of the IA.This review summarized research advances in the IA production from alternative substrates.In particular,the types of substrates as well as existing problems in the IA fermentation,strain breeding,and process regulation were discussed.And it is pointed that decreasing the price of the IA through use of alternative substrates and increasing the titer of the IA through genetic engineering should be further focused on to support the industrialization of the IA.展开更多
The Crabtree effect products ethanol and acetic acid can be used for itaconic acid(IA)production in Saccharomyces cerevisiae.However,both the IA synthesis and oxidative phosphorylation pathways were hampered by glucos...The Crabtree effect products ethanol and acetic acid can be used for itaconic acid(IA)production in Saccharomyces cerevisiae.However,both the IA synthesis and oxidative phosphorylation pathways were hampered by glucose repression when glucose was used as the substrate.This study aimed to improve IA titer by increasing gene expressions related to glucose derepression without impairing yeast growth on glucose.Engineering the acetyl-CoA synthesis pathway increased the titer of IA to 257 mg/L in a urea-based medium.Instead of entire pathway overexpression,we found that some signaling pathways regulating glucose repression were effective targets to improve IA production and respiratory capacity.As a consequence of the reduced inhibition,IA titer was further increased by knocking out a negative regulator of the mitochondrial retrograde signaling MKS1.SNF1/MIG1 signaling was disturbed by deleting the hexokinase HXK2 or an endoplasmic reticulum membrane protein GSF2.The shaking results showed that XYY286(BY4741,HO::cadA,Y::Dz.ada,208a::Mt.acs,Δhxk2,pRS415-cadA,pRS423-aac2)accumulated 535 mg/L IA in 168 h in the YSCGLU medium.qRT-PCR results verified that deletion of MKS1 or HXK2 upregulated the gene expressions of the IA synthesis and respiratory pathways during the growth on glucose.展开更多
Hydrocarbon-derived polymers have been utilized in various packaging applications, such as pouches, films, foamed containers, rigid containers, and multiple components for medical, food, and other uses. However, mount...Hydrocarbon-derived polymers have been utilized in various packaging applications, such as pouches, films, foamed containers, rigid containers, and multiple components for medical, food, and other uses. However, mounting environmental considerations increased knowledge of the harmful consequences of greenhouse gas emissions, landfills, and disposal difficulties. Rising oil prices are forcing researchers and businesses to produce environmentally friendly packaging. These new sustainability requirements are particularly suited to biomass-based products, instead of petroleum sources;sourced from biomass entities. More functional and performance-oriented packaging is necessary despite the widespread usage of bio-based materials like paper. As a result, the transition to eco-friendly packaging will necessitate the improvement of existing bio-derived packaging and the development of new bio-derived materials like biopolymer paper coatings. The goal of this brief study was to give a synopsis of the present status of bio-derived packaging and an insight into ongoing and prospective developments in sustainable next-generation paper coatings for the packaging industry.展开更多
Polyaspartic acid(PASP)composite,a scale inhibitor,was prepared from PASP,itaconic acid—acrylic acid—acrylic ester(IA-AA-AE)terpolymer and 2-phosphonobutane-1,2,4-tricarboxylic acid(PBTCA).The scale inhibition of PA...Polyaspartic acid(PASP)composite,a scale inhibitor,was prepared from PASP,itaconic acid—acrylic acid—acrylic ester(IA-AA-AE)terpolymer and 2-phosphonobutane-1,2,4-tricarboxylic acid(PBTCA).The scale inhibition of PASP composite and the effect of its synergism with a magnetic field on scale inhibition were investigated.Calcium carbonate crystals in scale samples were characterized by means of SEM and XRD.The static and dynamic experiments show that the chelating function of PASP composite for Ca2+can be enhanced by synergism with a magnetic field.Under Ca2+650 mg/L,HCO3-1,300 mg/L and PASPcomposite 4 mg/L,the scale inhibition rate of PASP composite in magnetic water can increase by 10%in static state and by 20%in dynamic experiments.Scanning electron microscope(SEM)and X-ray diffraction(XRD)results show that calcite and aragonite can be completely transformed into vaterite by using PASP composite.展开更多
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2022MB034)。
文摘Functional materials synthesized from bio-based building blocks are fascinating and challenging in the fields of chemistry and materials science.Herein,we present a versatile strategy for synthesizing bio-based stimulus-responsive polymers derived from itaconic acid(IA).Bearing an azobenzene-containing side chain,the IA-based epoxy polymer exhibited both photoresponsiveness and acid/base-stimulus responsiveness.With controllable manipulation of the stress field of the wrinkling IA-polymer film via the stress relaxation effect resulting from the reversible cis-trans isomerization of the azobenzene moieties or solvent-induced swelling of the film,various tailor-made patterned wrinkling surfaces were conveniently fabricated.More importantly,the azobenzene protonation/deprotonation yields a reversible visual color transformation between pale yellow and purple in the film,which allows these IA-based polymer-coated surfaces to be utilized as rewritable information storage media.Various elegant pattern information can be acid-printed and base-erased(within 10 s)for multiple cycles and legible for over one day under laboratory conditions.Notably,the aforementioned dual-stimulus responsiveness of the IA-based polymer film enables its surface to be applied in information encryption.This study not only paves a new avenue for the convenient fabrication of stimulus-responsive surfaces but also sheds light on the development of functional polymers through green engineering.
基金supported by the National Natural Science Foundation of China(Grant No.21978066)Basic Research Program of Hebei Province for Natural Science Foundation and Key Basic Research Project(Grant No.18964308D)the Key Program of Natural Science Foundation of Hebei Province(Grant No.B2020202048).
文摘Methacrylic acid,an important organic chemical,is commercially manufactured starting from fossil feedstock.The decarboxylation of itaconic acid derived for biomass is a green route to the synthesis of methacrylic acid.In view of the problems existing in the researches on this route such as use of noble metal catalyst,harsh reaction conditions and low desired-product yield,we prepared a series of hydroxyapatite catalysts with different Ca/P molar ratios and evaluated their catalytic performance.The results showed that the hydroxyapatite catalyst with a Ca/P molar ratio of 1.58 had the best catalytic activity.The highest yield of MAA up to 61.2%was achieved with basically complete conversion of itaconic acid under the suitable reaction conditions of 1 equivalent of NaOH,2 MPa of N_(2),250℃,and 2 h.On this basis,a reaction network for the decarboxylation of itaconic acid to methacrylic acid catalyzed by hydroxyapatite was established.With the aid of catalyst characterization using X-ray powder diffraction,NH3/CO2 temperature-programmed desorption,N_(2)physisorption,inductively coupled plasma optical emission spectrometry,and scanning electron microscopy,we found that the distribution of surface acid sites and basic sites,crystal growth orientation,texture properties and morphology of hydroxyapatite varied with the Ca/P molar ratio.Furthermore,the change of the crystal growth orientation and its influence on the surface acidity and alkalinity were clarified.
基金supported by National Natural Science Foundation of China(21978066)Basic Research Program of Hebei Province for Natural Science Foundation and Key Basic Research Project(18964308D)the Key Program of Natural Science Foundation of Hebei Province(B2020202048).
文摘The synthesis of methacrylic acid from biomass-derived itaconic acid is a green route,for it can get rid of the dependence on fossil resource.In order to solve the problems on this route such as use of a preciousmetal catalyst and a corrosive homogeneous alkali,we prepared a series of hydroxyapatite catalysts by an ionic liquid-assisted hydrothermal method and evaluated their catalytic performance.The results showed that the ionic liquid[Bmim]BF_(4) can affect the crystal growth of hydroxyapatite,provide fluoride ion for fluorination of hydroxyapatite,and adjust the surface acidity and basicity,morphology,textural properties,crystallinity,and composition of hydroxyapatite.The[Bmim]BF4 dosage and hydrothermal temperature can affect the fluoride ion concentration in the hydrothermal system,thus changing the degree of fluoridation of hydroxyapatite.High fluoride-ion concentration can lead to the formation of CaF_(2) and thus significantly decrease the catalytic performance of hydroxyapatite.The hydrothermal time mainly affects the growth of hydroxyapatite crystals on the c axis,leading to different catalytic performance.The suitable conditions for the preparation of this fluoridized hydroxyapatite are as follows:a mass ratio of[Bmim]BF4 to calcium salt=0.2:1,a hydrothermal time of 12 h,and a hydrothermal temperature of 130℃.A maximal methacrylic acid yield of 54.7%was obtained using the fluoridized hydroxyapatite under relatively mild reaction conditions(250℃ and 2 MPa of N_(2))in the absence of a precious-metal catalyst and a corrosive homogeneous alkali.
文摘The terpolymer of itaconic acid, acrylamide and 2-acrylamido-2-methyl-1-propane sulfonic acid was synthesized through the free-radical polymerization. The IR spectra confirmed that there was no olefinic band, while the TGA results revealed that the terpolymer was of high thermal stability.
文摘With N-vinyl-2-pyrrolidone (NVP) and itaconic acid(IA), poly(N-vinyl-2-pyrrolidone/itaconic acid)[P(NVP/IA)] hydrogel was synthesized by free radical solution polymerization. The structure of this (P(NVP/IA)) was characterized by IR. Effects of concentration of itaconic acid, amount of cross-link agent, N,N′-methylene-bis-acrylamide, reaction temperature, and time on properties of swelling ratio(SR) of the hydrogel were investigated.The results show that the best swelling property of the hydrogel is obtained at 50 ℃ and 1.5 h. pH sensitivity increases as the concentration of itaconic acid in the hydrogel system increases. Swelling ratio of the hydrogel decreases as the amount of cross-link agent increases.
基金the National Natural Science Foundatioo of China(No.30670566)the International S&T Cooperation Program of China(No.2006DFA33150)
文摘An improved process of hydrolysis of corn starch was adopted in the production of itaconic acid （IA）, the aim was to decrease the unfermentable reducing sugar （RS） in the medium from the beginning of the fermentation and to increase the crystallization efficiency of IA from the fermentation broth. The glucose （GS） syrups saccharified by several combinations of glucoamylase and pullulanase were investigated and used as the carbohydrate source of the fermentation medium for the spore-initiated submerged fermentations experiments. Compared with the conventional process （with pullulanase controlled）, the improved process decreased th.e RS residue in the fermentation broth from 3.01g/L to 1.35g/L and from 4.25g/L to 3.25g/L when the original RS of the medium were 100 and 120g/L, respectively. The crystallization efficiency of IA increased from 65% to 78.8% and from 69.58% to 82.81% with the original RS being 100 and 120g/L, respectively.
基金Supported by College Student Innovation and Entrepreneurship Training Program Innovation Training Project of Guilin Medical University(202410601031S202410601127)Regional Science Foundation Project of National Natural Science Foundation of China(82360718).
文摘This review summarizes the metabolic origin,pharmacological activities,and regulatory mechanisms of itaconic acid at the transcriptional,post-translational modification,and metabolic levels.Its potential application in various diseases is also discussed,providing a theoretical basis for the development of itaconic acid as an anti-inflammatory immunomodulatory agent.
基金supported by the National Key Research and Development Program of China(2023YFF1104104)the National Natural Science Foundation of China(32100439)+1 种基金the China National Postdoctoral Program for Innovative Talents(BX20240145)the Jiangsu Funding Program for Excellent Postdoctoral Talent(2024ZB009).
文摘Itaconic acid(ITA)is an unsaturated organic acid used in industrial production due to its versatility as a polymer building block.Engineering microbial cell factories for ITA biosynthesis from cost-effective and renewable raw materials has gained significant attention.Here,we performed combinatorial engineering using Saccharomyces cerevisiae to improve ITA production.First,exogenous cis-aconitic acid decarboxylase(CAD)was integrated into S.cerevisiae to construct the ITA-producing chassis.Then,the rate-limiting step was eliminated by changing the promoter that drives CAD expression to optimize ITA synthesis.A mitochondrial cis-aconitate transporter MTTA was also expressed to facilitate the transport of precursor,which resulted in an ITA titer of 244 mg/L.Furthermore,with overexpression of truncated citrate synthase tCIT2,an increased titer of 409 mg/L was obtained.Finally,the transport protein Qdr3 was overexpressed to enhance the export of ITA,resulting in a production of 578 mg/L in shake flask.In a 5-L bioreactor,the ITA titer reached 1.2 g/L,representing the highest reported level in S.cerevisiae.Overall,an advanced recombinant yeast strain was constructed for the efficient production of ITA via combinatorial metabolic engineering.
基金financially supported by the National Natural Science Foundation of China(51203176)the National Basic Research Program of China(2010CB631100)+3 种基金the Natural Science Foundation of Ningbo(2012A610095)the China Postdoctoral Science Foundation(2013M-540504)the Postdoctoral Science Foundation of Zhejiang Province(Bsh1201011)the Director Funds of the Ningbo Institute of Materials Technology and Engineering,Chinese Academy of Sciences(Y20224-QF06)
文摘A phosphorus-containing bio-based epoxy resin(EADI)was synthesized from itaconic acid(IA)and 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide(DOPO).As a matrix,its cured epoxy network with methyl hexahydrophthalic anhydride(MHHPA)as the curing agent showed comparable glass-transition temperature and mechanical properties to diglycidyl ether in a bisphenol A(DGEBA)system as well as good flame retardancy with UL94 V-0 grade during a vertical burning test.As a reactive flame retardant,its flame-resistant effect on DGEBA/MHHPA system as well as its influence on the curing behavior and the thermal and mechanical properties of the modified epoxy resin were investigated.Results showed that after the introduction of EADI,not only were the flame retardancy determined by vertical burning test,LOI measurement,and thermogravimetric analysis significantly improved,but also the curing reactivity,glass transition temperature(T g),initial degradation temperature for 5%weight loss(T d(5%)),and flexural modulus of the cured system improved as well.EADI has great potential to be used as a green flame retardant in epoxy resin systems.
基金supported by the National Natural Science Foundation of China(No.21778018)Research Program of State Key Laboratory of Bioreactor Engineering and the grant from the National Key Research and Development Program of China(2021YFC2100300)the Chinese Plastic Surgery Foundation(No.2020M671021).
文摘Itaconic acid(ITA),an effective alternative fossil fuel,derives from the bypass pathway of the tricarboxylic acid(TCA)cycle.Therefore,the imbalance of metabolic flux between TCA cycle and ITA biosynthetic pathway seriously limits the production of ITA.The optimization of flux distribution between biomass and production has the potential to the productivity of ITA.Based on the previously constructed strain Escherichia coli MG1655Δ1-SAS-3(ITA titer:1.87 g/L),a CRISPRi-mediated self-inducible system(CiMS),which contained a responsive module based on the ITA biosensor YpItcR/Pccl and a regulative CRISPRi-mediated interferential module,was developed to regulate the flux of the TCA cycle and to enhance the capacity of the strain to produce ITA.First,a higher ITA-yielding strain,Δ4-Prmd-SAS-3(ITA titer:3.20 g/L),derived fromΔ1-SAS-3,was constructed by replacing the promoter PJ23100,for the expression of ITA synthesis genes,with Prmd and knocking out the three bypass genes poxB,pflB,and ldhA.Subsequently,the CiMS was used to inhibit the expression of key genes icd,pykA,and sucCD to dynamically balance the metabolic flux between TCA cycle and ITA biosynthetic pathway during the ITA production stage.The constructed strainΔ4-Prmd-SAS-3 under the dynamic regulation of the CiMS,showed a 23%increase in the ITA titer,which reached 3.93 g/L.This study indicated that CiMS was a practical strategy to dynamically and precisely regulated the metabolic flux in microbial cell factories.
基金Natural Science Foundation of Jiangsu Province of China(No.BK20160150).
文摘Itaconic acid(IA)is a precursor of various chemicals,which has been on the US Department of Energy’s list of the top 12 platform chemicals that can potentially be produced from biomass.The IA is mainly produced through a bio-fermentation method with sugar as raw material.However,the high cost and low yield restrict the industrial application of the IA.This review summarized research advances in the IA production from alternative substrates.In particular,the types of substrates as well as existing problems in the IA fermentation,strain breeding,and process regulation were discussed.And it is pointed that decreasing the price of the IA through use of alternative substrates and increasing the titer of the IA through genetic engineering should be further focused on to support the industrialization of the IA.
基金Support for this study was provided by the China National Key Research and Development Program [2019YFA0904300].
文摘The Crabtree effect products ethanol and acetic acid can be used for itaconic acid(IA)production in Saccharomyces cerevisiae.However,both the IA synthesis and oxidative phosphorylation pathways were hampered by glucose repression when glucose was used as the substrate.This study aimed to improve IA titer by increasing gene expressions related to glucose derepression without impairing yeast growth on glucose.Engineering the acetyl-CoA synthesis pathway increased the titer of IA to 257 mg/L in a urea-based medium.Instead of entire pathway overexpression,we found that some signaling pathways regulating glucose repression were effective targets to improve IA production and respiratory capacity.As a consequence of the reduced inhibition,IA titer was further increased by knocking out a negative regulator of the mitochondrial retrograde signaling MKS1.SNF1/MIG1 signaling was disturbed by deleting the hexokinase HXK2 or an endoplasmic reticulum membrane protein GSF2.The shaking results showed that XYY286(BY4741,HO::cadA,Y::Dz.ada,208a::Mt.acs,Δhxk2,pRS415-cadA,pRS423-aac2)accumulated 535 mg/L IA in 168 h in the YSCGLU medium.qRT-PCR results verified that deletion of MKS1 or HXK2 upregulated the gene expressions of the IA synthesis and respiratory pathways during the growth on glucose.
文摘Hydrocarbon-derived polymers have been utilized in various packaging applications, such as pouches, films, foamed containers, rigid containers, and multiple components for medical, food, and other uses. However, mounting environmental considerations increased knowledge of the harmful consequences of greenhouse gas emissions, landfills, and disposal difficulties. Rising oil prices are forcing researchers and businesses to produce environmentally friendly packaging. These new sustainability requirements are particularly suited to biomass-based products, instead of petroleum sources;sourced from biomass entities. More functional and performance-oriented packaging is necessary despite the widespread usage of bio-based materials like paper. As a result, the transition to eco-friendly packaging will necessitate the improvement of existing bio-derived packaging and the development of new bio-derived materials like biopolymer paper coatings. The goal of this brief study was to give a synopsis of the present status of bio-derived packaging and an insight into ongoing and prospective developments in sustainable next-generation paper coatings for the packaging industry.
基金supported by the Natural Science Foundation of Hebei Province of China(B2004000749).
文摘Polyaspartic acid(PASP)composite,a scale inhibitor,was prepared from PASP,itaconic acid—acrylic acid—acrylic ester(IA-AA-AE)terpolymer and 2-phosphonobutane-1,2,4-tricarboxylic acid(PBTCA).The scale inhibition of PASP composite and the effect of its synergism with a magnetic field on scale inhibition were investigated.Calcium carbonate crystals in scale samples were characterized by means of SEM and XRD.The static and dynamic experiments show that the chelating function of PASP composite for Ca2+can be enhanced by synergism with a magnetic field.Under Ca2+650 mg/L,HCO3-1,300 mg/L and PASPcomposite 4 mg/L,the scale inhibition rate of PASP composite in magnetic water can increase by 10%in static state and by 20%in dynamic experiments.Scanning electron microscope(SEM)and X-ray diffraction(XRD)results show that calcite and aragonite can be completely transformed into vaterite by using PASP composite.
