The production of thermostable laccases from a native strain of the white-rot fungus Pycnoporus sanguineus isolated in Mexico was enhanced by testing different media and a combination of inducers including copper sulf...The production of thermostable laccases from a native strain of the white-rot fungus Pycnoporus sanguineus isolated in Mexico was enhanced by testing different media and a combination of inducers including copper sulfate（CuSO4）.The best conditions obtained from screening experiments in shaken flasks using tomato juice,CuSO4,and soybean oil were integrated in an experimental design.Enhanced levels of tomato juice as the medium,CuSO4and soybean oil as inducers（36.8%（v/v）,3 mmol/L,and 1%（v/v）,respectively） were determined for 10 L stirred tank bioreactor runs.This combination resulted in laccase titer of 143000 IU/L（2,2＇-azino-bis（3-ethylbenzthiazoline-6- sulfonic acid）,pH 3.0）,which represents the highest activity so far reported for P.sanguineus in a 10-L fermentor.Other interesting media resulting from the screening included glucose-bactopeptone which increased laccase activity up to 20000 IU/L,whereas the inducers Acid Blue 62 and Reactive Blue 19 enhanced enzyme production in this medium 10 times.Based on a partial characterization,the laccases of this strain are especially promising in terms of thermostability（half-life of 6.1 h at 60 °C） and activity titers.展开更多
In this paper,to better reveal the surface effect and the screening effect as well as the nonlinear multi-field coupling characteristic of the multifunctional piezoelectric semiconductor(PS)nanodevice,and to further i...In this paper,to better reveal the surface effect and the screening effect as well as the nonlinear multi-field coupling characteristic of the multifunctional piezoelectric semiconductor(PS)nanodevice,and to further improve its working performance,a magneto-mechanical-thermo coupling theoretical model is theoretically established for the extensional analysis of a three-layered magneto-electro-semiconductor coupling laminated nanoplate with the surface effect.Next,by using the current theoretical model,some numerical analyses and discussion about the surface effect,the corresponding critical thickness of the nanoplate,and the distributions of the physical fields(including the electron concentration perturbation,the electric potential,the electric field,the average electric displacement,the effective polarization charge density,and the total charge density)under different initial state electron concentrations,as well as their active manipulation via some external magnetic field,pre-stress,and temperature stimuli,are performed.Utilizing the nonlinear multi-field coupling effect induced by inevitable external stimuli in the device operating environment,this paper not only provides theoretical support for understanding the size-dependent tuning/controlling of carrier transport as well as its screening effect,but also assists the design of a series of multiferroic PS nanodevices.展开更多
基金supported by the National Science and Technology Council of Mexico(CONACYT)(No.192118)
文摘The production of thermostable laccases from a native strain of the white-rot fungus Pycnoporus sanguineus isolated in Mexico was enhanced by testing different media and a combination of inducers including copper sulfate（CuSO4）.The best conditions obtained from screening experiments in shaken flasks using tomato juice,CuSO4,and soybean oil were integrated in an experimental design.Enhanced levels of tomato juice as the medium,CuSO4and soybean oil as inducers（36.8%（v/v）,3 mmol/L,and 1%（v/v）,respectively） were determined for 10 L stirred tank bioreactor runs.This combination resulted in laccase titer of 143000 IU/L（2,2＇-azino-bis（3-ethylbenzthiazoline-6- sulfonic acid）,pH 3.0）,which represents the highest activity so far reported for P.sanguineus in a 10-L fermentor.Other interesting media resulting from the screening included glucose-bactopeptone which increased laccase activity up to 20000 IU/L,whereas the inducers Acid Blue 62 and Reactive Blue 19 enhanced enzyme production in this medium 10 times.Based on a partial characterization,the laccases of this strain are especially promising in terms of thermostability（half-life of 6.1 h at 60 °C） and activity titers.
基金supported by the National Natural Science Foundation of China(Nos.12072253,11972176,and 12062011)the Doctoral Science Fund of Lanzhou University of Technology of China(No.062002)the Opening Project from the State Key Laboratory for Strength and Vibration of Mechanical Structures of China(No.SV2021-KF-19)。
文摘In this paper,to better reveal the surface effect and the screening effect as well as the nonlinear multi-field coupling characteristic of the multifunctional piezoelectric semiconductor(PS)nanodevice,and to further improve its working performance,a magneto-mechanical-thermo coupling theoretical model is theoretically established for the extensional analysis of a three-layered magneto-electro-semiconductor coupling laminated nanoplate with the surface effect.Next,by using the current theoretical model,some numerical analyses and discussion about the surface effect,the corresponding critical thickness of the nanoplate,and the distributions of the physical fields(including the electron concentration perturbation,the electric potential,the electric field,the average electric displacement,the effective polarization charge density,and the total charge density)under different initial state electron concentrations,as well as their active manipulation via some external magnetic field,pre-stress,and temperature stimuli,are performed.Utilizing the nonlinear multi-field coupling effect induced by inevitable external stimuli in the device operating environment,this paper not only provides theoretical support for understanding the size-dependent tuning/controlling of carrier transport as well as its screening effect,but also assists the design of a series of multiferroic PS nanodevices.
