Exploration In Laccase Activities With Constant And Variable Temperature In Two Forest Soils Of Changbai Mountain

Laccase is also called f-or phenol oxidase.It is a kind of Polyphenol oxidase containing copper and can catalytic oxidation of polyphenol and amino benzene.It's one of the valuable lignin degrading enzymes,playing an important role in the transformation of soil organic matter and ecosystem carbon cycle.This article taking two types of forest,Coniferous forest and Deciduous broad-leaved forest as the research object.The temperature is set to constant temperature of 10 ? and 30 ?,daily cycle variable temperature between 10 ? and 30 ?,analysis of four kinds of temperature.Potentiometry was used to determine soil pH,Alkaline Hydrolysis Nitrogen was used to drtermine soil nitrogen content,Sodium Bicarbonate method was used to drtermine soil phosphorus content,then cultive soils in different temperature,Spectrophotometric method with ABTS as substrat was used to drtermine the change of soil absorbance values,and use Nonlinear fitting to calculate enzyme activity.The results of the study are as follows:Study on the physical and chemical properties in soils showed that the order of mass fraction of total carbon and nitrogen was Coniferous O>Broad-leaved O>Broad-leaved A>ConiferousA.The results of Alkaline Hydrolysis Nitrogenwas and Contenting of phosphorus in layer O on Bicarbonate was more,big differences with layer A.The pH of Broad-leaved forest was more than Coniferous forest,the content of water solube carbon in layer O was more than layer A,the microbial biomass carbon iof Broad-leaved forest was more than Coniferous forest,the order of soil respiratory rate was Coniferous O>Broad-leaved O>Broad-leaved A>ConiferousA.The above indicators found,there is negative correlation between total carbon and nitrogen?carbon nitrogen ratio?sodium bicarbonate?alkaline hydrolysis nitrogen?pH?water solube carbon and soil layers,with the increase of soil depth,the indicators have a downward trend.Study on constant temperature effect Changbai mountain with different incubation time of laccase activities showed,determined soil enzyme activity after preincubateing,founds that soil influence on the results above the forest types.Layer O was more than A,Coniferous forest was more than Broad-leaved forest.After incubating one month,founds that temperature influence on the results above the soil,and above the forest types.The change of laccase activities temperature was Constant Low>Variable Low>Constant High,O and A of no significant difference,the same as Coniferous and Broad-leaved.From interaction,Temperature X Forest types influence on results was more than Temperatur X Soil.After incubating two months,found that soil influence on the results above the temperature,and above the forest types.Layer O was more than layer A.the change of laccase activities in temperature was Constant Low>Variable Low>Constant High>Variable High,Coniferous slightly more than Broad-leaved.From interaction,Temperature X Forest types influence on results was more than TemperaturX Soil.After incubating four nonths,found that soil influence on the results above the forest types,and above the temperature.Layer O was more than layer A,Coniferous more than Broad-leaved,the change of laccase activities in temperature was Constant High>Variable Low>Variable High>Constant Low.From interaction,Temperature X Forest types influence on results was less than Temperatur×Soil.Study on constant temperature effect Changbai mountain with different kinds forests of laccase activities showed that soil influence on the results above the forest types and temperature.Layer O was more than layer A;Coniferous more than Broad-leaved;Three temperature of soils appeared Constant High>Variable temperature>Constant Low.From interaction,Temperature × Forest types influence on results was more than temperatur ×soil.From Temperature × Forest types interaction,laccase activities in different forest types was sensitive to the changes of temperature,existing significant difference.From Temperature × Soil interaction,laccase activities of layer A was not affected by temperature processing,layer O appeared Constant High>Constant Low.In addition,with incubate time increasing,laccase activities significantly different,appeared one monthincubating<two months incubating<without incubating<four months incubating?...