Non-aqueous Micellar Nature And Micellar Enzymatic Calorimetry Study

The property research of surfactant in non-aqueous solution can provide theoretical basis for the research of micelle enzyme catalysis of cellulase.Some cellulose is not water miscible, but it can be dissolved in certain organic solvent.The study of cellulose's degradation by cellulase in non-aqueous environment is a new research subject.The main contents are as follows:1.the determination and regularity of CMC and thermodynamic functionsThe power-time curves of the micelle formation process were determined for non-ionic surfactant(TX-100 and Brij35) in non-aqueous solution under different temperatures and different alcohols of different concentrations by titration microcalorimetry.From the corresponding volume of the lowest point of the curves,the critical micelle concentration(CMC) was determined;from the area up the curves,the thermal effect andâ–³H_m^θwere measured; according to the action principle of surfactant and thermodynamic theory,theâ–³G_m^θandâ–³S_m^θwere calculated.The conclusions were as follows:TX-100 and Brij35 in DMF system,theâ–³H_m^θandâ–³S_m^θincreased while the CMC andâ–³G_m^θdecreased with the increment of temperature in the presence of same alcohol's concentration and carbon number;the CMC,â–³H_m^θ,â–³G_m^θandâ–³S_m^θall decreased with the increment of alcohol's carbon number in the presence of same temperature and same alcohol's concentration;the CMC,â–³H_m^θ,â–³G_m^θandâ–³S_m^θdecreased with the increment of alcohol's concentration.2.the study of optimum condition of cellulose's enzyme catalysisAfter determining the concentration of substrate and the doseage of enzyme,the power-time curves of the Carboxymethyl Cellulose degradated by cellulose were separately measured by the TAM Air at different W₀,different acidity(pH) and different temperature(T) in different reverse micelles.Then Using reduced extent method,the apparent Michaelis constant(K_m) and the apparent maximum velocity(V_max) were calculated and the relationships between V_max and W₀, pH,T were established.So we obtained the optimum conditions of microcrystalline cellulose degradated by cellulase.In the reverse micelles of non-ionic surfactant Brij35/n-Hexanol/ cyclohexane,the optimum W₀ is 5.62,the optimum acidity is 4.92 and the optimum temperature is 318.88K.3.the influence of common ions on enzyme catalysis of celluloseThe power - time curves of enzyme catalysis without ions and with the existence of ions of the same or different concentrations were determined and analyzed.By comparing,the regularities of activation or inhibition of different ions of the same concentration or of the same ion of different concentrations to enzyme catalysis were seen.It was found that Na⁺ and K⁺ were active to the enzyme catalysis and the effect of K⁺ was weaker than that of Na⁺;Mg²⁺ and Ba²⁺ were inhibitory to the reaction and the effect of Mg²⁺ was weaker than that of Ba²⁺。Cl^- and NO₃^-were active to the enzyme catalysis and the effect of NO₃^- was weaker than that of Cl^-;SO₄^2- and SO₃^2- were inhibitory to the reaction and the effect of SO₄^2- was weaker than that of SO₃^2-.The innovation of this paper:1.Thermodynamic parameters which obtained by microcalorirnetric method and thermodynamic theory are used to characterize cellulose's enzyme catalysis and to determine the optimum condition of the enzyme catalysis.This is a new subject for enzyme catalysis research.2.microcalorimetric method is used to study the interactivity of non-ionic surfactant, cosurfactants and solvents in non-aqueous solution.The CMC and thermal effect are determined and the AH_m^θis obtained,then theâ–³G_m^θandâ–³S_m^θare calculated.This is a new method to gain CMC and thermodynamic function.