Purification and biochemical characterization of two laccase isoenzymes isolated from Trichoderma harzianum S7113 and its application for bisphenol A degradation

Abstract

Two laccase isoenzymes (LacA and LacB) were isolated from a novel Trichoderma harzianum S7113 isolate employing ammonium sulfate precipitation, Sephadex G100, and DEAE Sepharose ion exchange chromatography. The molecular weights of the purified LacA and LacB laccases were estimated to be 63 and 48 kDa, respectively. The two isoenzymes had their optimum activities at the same temperature (50 °C), but at slightly different pH values (pH 3.0 for LacA and pH 2.5 for LacB). LacA and LacB had the same thermal stability at 40 °C and pH stability at pH 9.0. The two isoenzymes also showed a high level of specific activity toward ABTS, where the Km values of LacA and LacB were 0.100 and 0.065 mM, whereas their Vmax values were 0.603 and 0.182 µmol min−1, respectively. LacA and LacB catalytic activity was stimulated by Mg2+, Zn2+, K+, and Ni2+, whereas it was inhibited by Hg2+ and Pb2+, β-mercaptoethanol, EDTA, and SDS, and completely inhibited by sodium azide. Our findings indicate that purified laccase has a promising capacity for bisphenol A (BPA) bioremediation across a broad pH range. This finding opens up new opportunities for the commercialization of this technique in a variety of biotechnology-based applications, particularly for removing endocrine chemicals from the environment.

Laccase-Conjugated Nanostructured ZnFe2O4/rGO-Modified Electrode-Based Interfaces for Electrochemical Impedance Monitoring of Adrenaline: A Promising Biosensor for Management of Neurodegenerative Disorders

“…The change in pH also influences the binding of AD to the enzyme or the electron-transfer kinetics at the electrode surface. Highly acidic or alkaline conditions may lead to corrosion or degradation of the electrode material, , which can affect the reliability of the biosensor. Thus, the pH influences are optimized by the voltametric estimation of AD using a fabricated electrode La/ZF/rGO/ITO utilized in various pH solutions ranging from 5.7 to 8 at SEP. Figure C indicates the significant impacts of pH on the oxidation peak current ( I pa ).…”

Kinetic studies on optimized extracellular laccase from Trichoderma harzianum PP389612 and its capabilities for azo dye removal

“…Bagewadi [17] purified 56.0 kDa laccase from Trichoderma harzianum HZN10. Meanwhile, two laccase isozymes from Trichoderma harzianum S7113 were isolated at molecular weights of 48 and 63 kDa by Elsayed et al [78]. These variations were noted in the molecular sizes of the laccase enzyme generated from the same organism, T. harizanum isolates.…”

Improvement of Laccase Production by Thielavia terrestris Co3Bag1. Enhancing the Bio-Catalytic Performance of the Native Thermophilic TtLacA via Immobilization in Copper Alginate Gel Beads

“…This contrasts with the stimulatory effect of Fe 2+ for the laccases from Methylobacterium extorquens [ 75 ], T. hirsuta MX2 [ 76 ], G. austral [ 52 ], and T. polyzona WRF03 [ 49 ]. Strong inhibition of laccases from T. hirsuta [ 74 ] and, T. harzianum S7113 [ 77 ] by Hg 2+ has been registered. Inhibition by Hg 2+ ions might be due to the strong binding affinity of these ions for sulfhydryl groups, present on histidine residues of the catalytic site involved in binding the four copper atoms, thus causing enzyme deactivation [ 2 , 78 ].…”