Enzymatic Characteristics of Aspergillus flavus Pectinase and Its Application in the Hydrolysis of Fallen Leaves of Magnolia denudata
Returning crop residues to the field can improve soil quality.However,the low microbial activity hinders the decomposition process.Pectinase-producing strains were isolated from the soil to accelerate the decomposition process.The strain screened out was identified and the enzymatic properties of the pectinase produced by the strain were analyzed.Furthermore,the hydrolytic effect of the produced pectinase on the fall-en leaves of Magnolia denudata was studied.The results showed that the strain isolated from the soil was i-dentified as Aspergillus flavus TPF2-1,and the activity of its crude pectinase was(0.63±0.02)IU/mL.With polygalacturonic acid as the substrate,the crude pectinase of TPF2-1 showcased the highest activity at pH value 4.5 and 50 ℃.There was no loss of enzyme activity after incubation at 35 ℃ for 1 h.After incuba-tion at pH value 4.0-7.0 and 25 ℃ for 24 h,the relative activity of the enzyme was still above 90％.Li+,Na+,Mg2+,K+,Cu,Zn2+and Co2+at concentrations of 1,2 and 5 mmol/L had no significant inhibitory effect on the activity of the crude pectinase of TPF2-1,while Ca2+,Fe2+and Fe3+only showed inhibitory effects at a concentration of 5 mmol/L.The crude pectinase of TPF2-1 increased the amount of reducing sug-ar in the hydrolysis system of M.denudata fallen leaves to 3.3 times that before hydrolysis.The results of this study indicate that the pectinase from A.flavus has a potential application value in the returning of plant leaves to the field.
pectinaseenzymatic propertiesAspergillus flavusstrain isolation and identificationfallen leaves hydrolysis
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维普
