Rhizopus oryzae lipase(ROL)was immobilized on the surface of silica coated amino modified CoFe_(2)O_4 nanoparticles and applied for biodiesel production.The results indicated more affinity of the ROL toward its substr...Rhizopus oryzae lipase(ROL)was immobilized on the surface of silica coated amino modified CoFe_(2)O_4 nanoparticles and applied for biodiesel production.The results indicated more affinity of the ROL toward its substrate upon immobilization,as revealed by a lower Km value for the immobilized ROL compared to its free counterpart.Intrinsic fluorescence spectroscopy indicated a lower intensity for ROL immobilized on CoFe_(2)O_4 nanoparticles.Besides,immobilized ROL steady state anisotropy measurements presented lower values,which implied assembly of ROL molecules on magnetic nanoparticles upon immobilization as well as their restricted rotation upon covalent attachment.Thermal stability analysis revealed improved activity at higher temperatures for the immobilized enzyme compared to its free counterpart.Accordingly,Pace analysis to determine protein thermal stability revealed preservation of the protein conformation in the presence of increasing temperatures upon immobilization on nanoparticles.Finally,ROL immobilized on CoFe_(2)O_(4)nanoparticles exhibited improved efficiency of biodiesel production in agreement with thermal activity profile.Therefore,the authors suggest application of the lipase molecules immobilized on CoFe_(2)O_(4)nanoparticles for more efficient biodiesel production.展开更多
1,3-Dioleoyl-2-palmitoylglycerol(OPO)has been a hotspot of functional oils research in recent years,but due to the high cost of sn-1,3 specific lipase in enzymatic synthesis and the lack of biocatalyst stability,large...1,3-Dioleoyl-2-palmitoylglycerol(OPO)has been a hotspot of functional oils research in recent years,but due to the high cost of sn-1,3 specific lipase in enzymatic synthesis and the lack of biocatalyst stability,large-scale industrial application is difficult.In this study,the prepared magnetic ZnFe_(2)O_(4) was functionalized with dopamine to obtain ZnFe_(2)O_(4)@PDA,and the nano-biocatalyst ZnFe_(2)O_(4)@PDA@RML was prepared by immobilizing sn-1,3 specific lipase of Rhizomucor miehei lipase(RML)via a cross-linking method.The existence of RML on ZnFe_(2)O_(4)@PDA was confirmed by XRD,FTIR,SEM,and TEM.This strategy proved to be simple and effective because the lipase immobilized on magnetic nanoparticles could be quickly recovered using external magnets,enabling reuse of the lipase.The activity,adaptability to a high temperature,pH value,and operational stability of immobilized RML were superior to those of free RML.After optimizing the synthesis conditions,the OPO yield was 42.78%,and the proportion of PA at the sn-2 position(PA-Sn2)was 54.63%.After the first four cycles,the activity of ZnFe_(2)O_(4)@PDA@RML was not significantly affected.The magnetically immobilized lipase has good thermal stability,long-term storage stability,reusability,and high catalytic activity.It can be used as a green and efficient biocatalyst to synthesize the OPO functional lipid.展开更多
Pseudomonas cepacia lipase (PSL) immobilized on the carboxyl-functionalized meso-cellular foams (HOOC-MCF) was used for the transesterification resolution of (R,S)-l-phenylethanol in organic solvent. The results...Pseudomonas cepacia lipase (PSL) immobilized on the carboxyl-functionalized meso-cellular foams (HOOC-MCF) was used for the transesterification resolution of (R,S)-l-phenylethanol in organic solvent. The results showed that the ee value of (S)-1- phenylethanol and (R)-1-phenylethyl acetate reached 99% with 50% conversion of 1-phenylethanol using toluene as solvent. Furthermore, it was found that PSL/HOOC-MCF exhibited high enantioselectivity in organic solvent with log P ≤ 2 such as toluene and hexane.展开更多
Introduction The formation of gelatin-containing mieroemulsionbased gels(MBGs) was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techni...Introduction The formation of gelatin-containing mieroemulsionbased gels(MBGs) was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techniques including tracer diffusion, electrical conductivity, NMR, X-ray and small angle neutron scattering. The MBGs were proposed to comprise an extensive, rigid, interconnected network of gelatin/water rods stabilized by a monolayer of surfactant, in coexistence with a po- pulation of conventional W/O microemulsion droplets.展开更多
CTAB/TX-100 microemtdsion-based gel(MBG), which could be soaked in aqueous solution for a long time without mechanical strength and shape changes, was successfully prepared. Lipase immobilized in this gel had a high...CTAB/TX-100 microemtdsion-based gel(MBG), which could be soaked in aqueous solution for a long time without mechanical strength and shape changes, was successfully prepared. Lipase immobilized in this gel had a higher activity than that in CTAB MBG when catalyzed the esterification reaction between n-hexanoic acid and n-octanol and its enantioselectivity was slightly higher when catalyzed the stereoselective esterification reaction between racemic ibuprofen and n-octanol. In aqueous solution, lipase in CTAB/TX-100 MBG could catalyze smoothly the hydrolysis reaction of olive oil and could be reused many times without the evident change of MBG mechanical strength although its activity decreased 41.8% after nine-time recycles.展开更多
The rational design of nano-carriers is critical for modem enzyme immobilization for advanced biocatalysis. Herein, we report the synthesis of octadecylalkyl- modified mesoporous-silica nanoparticles (C18-MSNs) with...The rational design of nano-carriers is critical for modem enzyme immobilization for advanced biocatalysis. Herein, we report the synthesis of octadecylalkyl- modified mesoporous-silica nanoparticles (C18-MSNs) with a high C18 content (-19 wt.%) and tunable pore sizes (1.6--13 nm). It is demonstrated that the increased hydrophobic content and a tailored pore size (slightly larger than the size of lipase) are responsible for the high performance of immobilized lipase. The optimized C18-MSNs exhibit a loading capacity of 711 mg/g and a specific activity 5.23 times higher than that of the free enzyme. Additionally, 93% of the initial activity is retained after reuse five times, which is better than the best performance reported to date. Our findings pave the way for the robust immobilization of lipase for biocatalytic applications.展开更多
As an alternative biodegradable aliphatic polyester,poly(w-pentadecalactone-co-ε-caprolactone)copolymer was synthesized via enzymatic ring-opening polymerization.A new biocatalyst,Candida antarctica lipase B,immobili...As an alternative biodegradable aliphatic polyester,poly(w-pentadecalactone-co-ε-caprolactone)copolymer was synthesized via enzymatic ring-opening polymerization.A new biocatalyst,Candida antarctica lipase B,immobilized onto rice husk ash was used for catalysis.Reactions were carried out at various temperatures and periods for varied copolymer compositions in order to obtain the highest molecular weight copolymer.The best reaction parameters were found to be 80℃ and 6 hours and molecular weights increased proportionally with the amount of w-pentadecalactone(w-PDL).The molecular structure of copolymer with 75%weight ratio of w-PDL(Mn=19720 g/mol)was characterized by proton and carbon nuclear magnetic resonance spectroscopies(^1H-NMR and ^13C-NMR).Thermal properties of the same copolymer and homopolymers were investigated by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA).Improved thermal features were shown by addition of w-PDL to the structure and compared with poly(ε-caprolactone)(PCL).Consequently,poly(w-pentadecalactone-co-ε-caprolactone)copolymers were found to be good alternatives to widely used polyester,PCL,with their rapid polymerization tendency,higher molecular weights,and improved thermal features.展开更多
1 Results Enzyme catalysis is most attractive for the synthesis and modification of biologically relevant classes of fine organic compounds, which are difficult to prepare and to handle by conventional means[1]. In th...1 Results Enzyme catalysis is most attractive for the synthesis and modification of biologically relevant classes of fine organic compounds, which are difficult to prepare and to handle by conventional means[1]. In this study, commercial immobilized lipase from Candida antarctica (Novozym 435) was used in the preparation of fine organic compound with excellent properties and application as raw material for cosmetic formulation - oleyl palmitate. The effect of various reaction parameters were optimized c...展开更多
We report an efficient kinetic resolution of racemic 2-(4-chlorophenyl)-4-hydroxytetrahydro-pyran (CLP-4-HTHP) via Pseudomonas cepacia lipase (PSL)-catalyzed transesterification, where PSL is immobilized on a co...We report an efficient kinetic resolution of racemic 2-(4-chlorophenyl)-4-hydroxytetrahydro-pyran (CLP-4-HTHP) via Pseudomonas cepacia lipase (PSL)-catalyzed transesterification, where PSL is immobilized on a core-shell MnFe204@SiO2-(CH2)3-NH2 carrier and used as a magnetically separable catalyst. The as-synthesized PSL/MnFe204@SiO2-(CH2)3-NH2 catalyst exhibits enhanced catalytic activity for resolving racemic CLP-4-HTHP to the corresponding optically pure (2R,4S)-CLP-4-HTHP compared to the free PSL. The ees for the former is 2.3 times larger than that for the latter under optimized conditions (99.4% and 44.1%, respectively), although the eep for them are same (99.2%). Meanwhile, the PSL/MnFe204@SiO2-(CH2)3-NH2 catalyst possesses a high saturate magnetization of 59.7 emu/g and could be easily recovered by magnetic separation and reused. The catalytic activity in six recycling tests did not significantly decrease, suggesting its great potential for industrial applications.展开更多
基金financially supported by Research Institute of Applied Science(RIAS)ACECRInstitute of Biochemistry and Biophysics(IBB)Iran National Science Foundation(INSF)。
文摘Rhizopus oryzae lipase(ROL)was immobilized on the surface of silica coated amino modified CoFe_(2)O_4 nanoparticles and applied for biodiesel production.The results indicated more affinity of the ROL toward its substrate upon immobilization,as revealed by a lower Km value for the immobilized ROL compared to its free counterpart.Intrinsic fluorescence spectroscopy indicated a lower intensity for ROL immobilized on CoFe_(2)O_4 nanoparticles.Besides,immobilized ROL steady state anisotropy measurements presented lower values,which implied assembly of ROL molecules on magnetic nanoparticles upon immobilization as well as their restricted rotation upon covalent attachment.Thermal stability analysis revealed improved activity at higher temperatures for the immobilized enzyme compared to its free counterpart.Accordingly,Pace analysis to determine protein thermal stability revealed preservation of the protein conformation in the presence of increasing temperatures upon immobilization on nanoparticles.Finally,ROL immobilized on CoFe_(2)O_(4)nanoparticles exhibited improved efficiency of biodiesel production in agreement with thermal activity profile.Therefore,the authors suggest application of the lipase molecules immobilized on CoFe_(2)O_(4)nanoparticles for more efficient biodiesel production.
基金This research was funded by the Science and Technology Program in Guangzhou City of China(Grant No.201904010087)the National College Students Innovation and Entrepreneurship Training Program of China(Grant No.202111347022)+2 种基金the Science and Technology Innovation Fund for Graduate Students(Grant No.KJCX2021005)Innovative Team Projects of Universities in Guangdong Province of China(Grant No.2016KCXTD003)2021 Guangdong University Research Platform and Scientific Research Project(Grant No.2021ZDZX2056).
文摘1,3-Dioleoyl-2-palmitoylglycerol(OPO)has been a hotspot of functional oils research in recent years,but due to the high cost of sn-1,3 specific lipase in enzymatic synthesis and the lack of biocatalyst stability,large-scale industrial application is difficult.In this study,the prepared magnetic ZnFe_(2)O_(4) was functionalized with dopamine to obtain ZnFe_(2)O_(4)@PDA,and the nano-biocatalyst ZnFe_(2)O_(4)@PDA@RML was prepared by immobilizing sn-1,3 specific lipase of Rhizomucor miehei lipase(RML)via a cross-linking method.The existence of RML on ZnFe_(2)O_(4)@PDA was confirmed by XRD,FTIR,SEM,and TEM.This strategy proved to be simple and effective because the lipase immobilized on magnetic nanoparticles could be quickly recovered using external magnets,enabling reuse of the lipase.The activity,adaptability to a high temperature,pH value,and operational stability of immobilized RML were superior to those of free RML.After optimizing the synthesis conditions,the OPO yield was 42.78%,and the proportion of PA at the sn-2 position(PA-Sn2)was 54.63%.After the first four cycles,the activity of ZnFe_(2)O_(4)@PDA@RML was not significantly affected.The magnetically immobilized lipase has good thermal stability,long-term storage stability,reusability,and high catalytic activity.It can be used as a green and efficient biocatalyst to synthesize the OPO functional lipid.
基金financially supported by the National Natural Science Foundation of China(No.50662004)the State Key Program of Fundamental Research(No.2004CCA05900).
文摘Pseudomonas cepacia lipase (PSL) immobilized on the carboxyl-functionalized meso-cellular foams (HOOC-MCF) was used for the transesterification resolution of (R,S)-l-phenylethanol in organic solvent. The results showed that the ee value of (S)-1- phenylethanol and (R)-1-phenylethyl acetate reached 99% with 50% conversion of 1-phenylethanol using toluene as solvent. Furthermore, it was found that PSL/HOOC-MCF exhibited high enantioselectivity in organic solvent with log P ≤ 2 such as toluene and hexane.
基金Supported by the Natural Science Foundation of Shandong Province in China(No.Y2003B01).
文摘Introduction The formation of gelatin-containing mieroemulsionbased gels(MBGs) was first described in 1986 and the physical/structural characterization was carried out by a number of groups with a variety of techniques including tracer diffusion, electrical conductivity, NMR, X-ray and small angle neutron scattering. The MBGs were proposed to comprise an extensive, rigid, interconnected network of gelatin/water rods stabilized by a monolayer of surfactant, in coexistence with a po- pulation of conventional W/O microemulsion droplets.
基金Supported by the National Natural Science Foundation of China(No. 20803044)the Foundation of Key Laboratory of Colloid and Interface Chemistry of Ministry of Education,Shandong University,China(No.200714)
文摘CTAB/TX-100 microemtdsion-based gel(MBG), which could be soaked in aqueous solution for a long time without mechanical strength and shape changes, was successfully prepared. Lipase immobilized in this gel had a higher activity than that in CTAB MBG when catalyzed the esterification reaction between n-hexanoic acid and n-octanol and its enantioselectivity was slightly higher when catalyzed the stereoselective esterification reaction between racemic ibuprofen and n-octanol. In aqueous solution, lipase in CTAB/TX-100 MBG could catalyze smoothly the hydrolysis reaction of olive oil and could be reused many times without the evident change of MBG mechanical strength although its activity decreased 41.8% after nine-time recycles.
文摘The rational design of nano-carriers is critical for modem enzyme immobilization for advanced biocatalysis. Herein, we report the synthesis of octadecylalkyl- modified mesoporous-silica nanoparticles (C18-MSNs) with a high C18 content (-19 wt.%) and tunable pore sizes (1.6--13 nm). It is demonstrated that the increased hydrophobic content and a tailored pore size (slightly larger than the size of lipase) are responsible for the high performance of immobilized lipase. The optimized C18-MSNs exhibit a loading capacity of 711 mg/g and a specific activity 5.23 times higher than that of the free enzyme. Additionally, 93% of the initial activity is retained after reuse five times, which is better than the best performance reported to date. Our findings pave the way for the robust immobilization of lipase for biocatalytic applications.
文摘As an alternative biodegradable aliphatic polyester,poly(w-pentadecalactone-co-ε-caprolactone)copolymer was synthesized via enzymatic ring-opening polymerization.A new biocatalyst,Candida antarctica lipase B,immobilized onto rice husk ash was used for catalysis.Reactions were carried out at various temperatures and periods for varied copolymer compositions in order to obtain the highest molecular weight copolymer.The best reaction parameters were found to be 80℃ and 6 hours and molecular weights increased proportionally with the amount of w-pentadecalactone(w-PDL).The molecular structure of copolymer with 75%weight ratio of w-PDL(Mn=19720 g/mol)was characterized by proton and carbon nuclear magnetic resonance spectroscopies(^1H-NMR and ^13C-NMR).Thermal properties of the same copolymer and homopolymers were investigated by differential scanning calorimetry(DSC)and thermogravimetric analysis(TGA).Improved thermal features were shown by addition of w-PDL to the structure and compared with poly(ε-caprolactone)(PCL).Consequently,poly(w-pentadecalactone-co-ε-caprolactone)copolymers were found to be good alternatives to widely used polyester,PCL,with their rapid polymerization tendency,higher molecular weights,and improved thermal features.
文摘1 Results Enzyme catalysis is most attractive for the synthesis and modification of biologically relevant classes of fine organic compounds, which are difficult to prepare and to handle by conventional means[1]. In this study, commercial immobilized lipase from Candida antarctica (Novozym 435) was used in the preparation of fine organic compound with excellent properties and application as raw material for cosmetic formulation - oleyl palmitate. The effect of various reaction parameters were optimized c...
基金financially supported by the National Natural Science Foundation of China (Nos. 21064005 and 21263020)the National Basic Research Program 973 (No. 2012CB723106)
文摘We report an efficient kinetic resolution of racemic 2-(4-chlorophenyl)-4-hydroxytetrahydro-pyran (CLP-4-HTHP) via Pseudomonas cepacia lipase (PSL)-catalyzed transesterification, where PSL is immobilized on a core-shell MnFe204@SiO2-(CH2)3-NH2 carrier and used as a magnetically separable catalyst. The as-synthesized PSL/MnFe204@SiO2-(CH2)3-NH2 catalyst exhibits enhanced catalytic activity for resolving racemic CLP-4-HTHP to the corresponding optically pure (2R,4S)-CLP-4-HTHP compared to the free PSL. The ees for the former is 2.3 times larger than that for the latter under optimized conditions (99.4% and 44.1%, respectively), although the eep for them are same (99.2%). Meanwhile, the PSL/MnFe204@SiO2-(CH2)3-NH2 catalyst possesses a high saturate magnetization of 59.7 emu/g and could be easily recovered by magnetic separation and reused. The catalytic activity in six recycling tests did not significantly decrease, suggesting its great potential for industrial applications.