Adsorption of Trametes versicolor laccase to soil iron and aluminum minerals: enzyme activity, kinetics and stability studies.
Laccases play an important role in the degradation of soil phenol or phenol-like substance and can be potentially used in soil remediation through immobilization. Iron and aluminum minerals can adsorb extracellular enzymes in soil environment. In the present study, we investigated the adsorptive interaction of laccase, from the white-rot fungus Trametes versicolor, with soil iron and aluminum minerals and characterized the properties of the enzyme after adsorption to minerals. Results showed that both soil iron and aluminum minerals adsorbed great amount of laccase, independent of the mineral specific surface areas. Adsorbed laccases retained 26-64% of the activity of the free enzyme. Compared to the free laccase, all adsorbed laccases showed higher Km values and lower Vmax values, indicating a reduced enzyme-substrate affinity and a lower rate of substrate conversion in reactions catalyzed by the adsorbed laccase. Adsorbed laccases exhibited increased catalytic activities compared to the free laccase at low pH, implying the suitable application of iron and aluminum mineral-adsorbed T. versicolor laccase in soil bioremediation, especially in acid soils. In terms of the thermal profiles, adsorbed laccases showed decreased thermal stability and higher temperature sensitivity relative to the free laccase. Moreover, adsorption improved the resistance of laccase to proteolysis and extended the lifespan of laccase. Our results implied that adsorbed T. versicolor laccase on soil iron and aluminum minerals had promising potential in soil remediation.
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: uptowuyue@163.com.
Yue
Y
Wu
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: jy27486@163.com.
Ying
Y
Jiang
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: jiaguojiao@njau.edu.cn.
Jiaguo
J
Jiao
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: liumq@njau.edu.cn.
Manqiang
M
Liu
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: fenghu@njau.edu.cn.
Feng
F
Hu
SRUC, Crop and Soil Systems Research Group, Edinburgh EH9 3JG UK. Electronic address: Bryan.Griffiths@sruc.ac.uk.
Bryan S
BS
Griffiths
Soil Ecology Lab, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: huixinli@njau.edu.cn.
Huixin
H
Li
D000327:Adsorption; D000535:Aluminum / Q000378:metabolism*; D052160:Benzothiazoles / Q000378:metabolism; D001673:Biodegradation, Environmental; D004795:Enzyme Stability; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000378:metabolism*; D007700:Kinetics; D042845:Laccase / Q000378:metabolism*; D008903:Minerals / Q000378:metabolism*; D010447:Peptide Hydrolases / Q000378:metabolism; D012987:Soil / Q000737:chemistry*; D013451:Sulfonic Acids / Q000378:metabolism; D013696:Temperature; D055454:Trametes / Q000201:enzymology*
D052160:Benzothiazoles; D006812:Humic Substances; D008903:Minerals; D012987:Soil; D013451:Sulfonic Acids; C002502:2,2'-azino-di-(3-ethylbenzothiazoline)-6-sulfonic acid; D000535:Aluminum; D007501:Iron; D042845:Laccase; D010447:Peptide Hydrolases
Adsorption; Characteristics; Soil aluminum mineral; Soil iron mineral; Trametes versicolor laccase