As a natural aromatic polymer,lignin has great potential but limited industrial application due to its complex chemical structure.Among strategies for lignin conversion,biodegradation has attracted promising interest ...As a natural aromatic polymer,lignin has great potential but limited industrial application due to its complex chemical structure.Among strategies for lignin conversion,biodegradation has attracted promising interest recently in term of efficiency,selectivity and mild condition.In order to overcome the issues of poor stability and non-reusability of enzyme in the biodegradation of lignin,this work explored a protocol of immobilized laccase on magnetic nanoparticles(MNPs)with rough surfaces for enhanced lignin model compounds degradation.Scanning electron microscope with energy dispersive spectrometer(SEM-EDS),flourier transformation infrared spectroscopy(FTIR)and thermal gravimetric analysis(TGA)were utilized to characterize the immobilization of laccase.The results showed a maximum activity recovery of 64.7%towards laccase when it was incubated with MNPs and glutaraldehyde(GA)with concentrations of 6 mg·ml^-1and 7.5 mg·ml^-1for 5 h,respectively.The immobilized laccase showed improved thermal stability and pH tolerance compared with free laccase,and remained more than 80%of its initial activity after 20 days of storage at 4℃.In addition,about 40%residual activity of the laccase remained after 8 times cycles.Gas chromatography–mass spectrometry(GC–MS)was utilized to characterize the products of lignin model compound degradation and activation,and the efficiency of immobilized laccase was calculated to be 1–5 times that of free laccase.It was proposed that the synergistic effect between MNPs and laccase displays an important role in the enhancement of stability and activity in lignin model compound biodegradation.展开更多
The authors regret that Fig.7b in our original article was incorrectly published,which is the same as Fig.6b due to an unintentional and random error.The correct Fig.7b is shown as follows(Reusability of the immobiliz...The authors regret that Fig.7b in our original article was incorrectly published,which is the same as Fig.6b due to an unintentional and random error.The correct Fig.7b is shown as follows(Reusability of the immobilized laccase).The change does not affect the results and conclusions.展开更多
Acetate-based imidazolium ionic liquids(ILs)are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deproton...Acetate-based imidazolium ionic liquids(ILs)are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deprotonation,by which the IL based biomass processing will be challenging.Herein,we demonstrated that the thermal stability of normal acetate-based imidazolim[C8C1Im][OAc]could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL([C4C1Im][NTf2]).When the molar fraction of[C8C1Im][OAc]was 0.3,the thermal stability of[C8C1Im][OAc]could be significantly improved(ΔT5%dec=+43°C).Detailed information obtained from thermal gravimetric analysis(TGA)and nuclear magnetic resonance(NMR)revealed that the addition of[C4C1 Im][NTf2]played a significant role in enhancing the thermal stability of[C8C1Im][OAc].It was proposed that the formation of an anion–π+structure network between[C8C1 Im][OAc]and[C4C1Im][NTf2]via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.展开更多
基金supported by the Startup Foundation of Beijing Institute of Technology,China(3160011181808)。
文摘As a natural aromatic polymer,lignin has great potential but limited industrial application due to its complex chemical structure.Among strategies for lignin conversion,biodegradation has attracted promising interest recently in term of efficiency,selectivity and mild condition.In order to overcome the issues of poor stability and non-reusability of enzyme in the biodegradation of lignin,this work explored a protocol of immobilized laccase on magnetic nanoparticles(MNPs)with rough surfaces for enhanced lignin model compounds degradation.Scanning electron microscope with energy dispersive spectrometer(SEM-EDS),flourier transformation infrared spectroscopy(FTIR)and thermal gravimetric analysis(TGA)were utilized to characterize the immobilization of laccase.The results showed a maximum activity recovery of 64.7%towards laccase when it was incubated with MNPs and glutaraldehyde(GA)with concentrations of 6 mg·ml^-1and 7.5 mg·ml^-1for 5 h,respectively.The immobilized laccase showed improved thermal stability and pH tolerance compared with free laccase,and remained more than 80%of its initial activity after 20 days of storage at 4℃.In addition,about 40%residual activity of the laccase remained after 8 times cycles.Gas chromatography–mass spectrometry(GC–MS)was utilized to characterize the products of lignin model compound degradation and activation,and the efficiency of immobilized laccase was calculated to be 1–5 times that of free laccase.It was proposed that the synergistic effect between MNPs and laccase displays an important role in the enhancement of stability and activity in lignin model compound biodegradation.
文摘The authors regret that Fig.7b in our original article was incorrectly published,which is the same as Fig.6b due to an unintentional and random error.The correct Fig.7b is shown as follows(Reusability of the immobilized laccase).The change does not affect the results and conclusions.
基金financially supported by the National Natural Science Foundation of China(21776026)the Liaoning Revitalization Talents Program(XLYC1902037)the start-up research funding of Beijing Institute of Technology(3160011181808)。
文摘Acetate-based imidazolium ionic liquids(ILs)are of great importance and widely applied in biomass processing and engineering but under stability issue due to the structure self–rearrangement induced by C2–H deprotonation,by which the IL based biomass processing will be challenging.Herein,we demonstrated that the thermal stability of normal acetate-based imidazolim[C8C1Im][OAc]could be significantly improved by changing its cation and anion environment with the presence of 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide IL([C4C1Im][NTf2]).When the molar fraction of[C8C1Im][OAc]was 0.3,the thermal stability of[C8C1Im][OAc]could be significantly improved(ΔT5%dec=+43°C).Detailed information obtained from thermal gravimetric analysis(TGA)and nuclear magnetic resonance(NMR)revealed that the addition of[C4C1 Im][NTf2]played a significant role in enhancing the thermal stability of[C8C1Im][OAc].It was proposed that the formation of an anion–π+structure network between[C8C1 Im][OAc]and[C4C1Im][NTf2]via strong hydrogen bond interactions greatly affects the environment of hydrogen atom in the imidazolium ring of each IL.
