1. Production and characterization of novel thermostable CotA-laccase from Bacillus altitudinis SL7 and its application for lignin degradation.
- Author
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Khan SI, Sahinkaya M, Colak DN, Zada NS, Uzuner U, Belduz AO, Çanakçi S, Khan AZ, Khan S, Badshah M, and Shah AA
- Subjects
- Lignin metabolism, Molecular Docking Simulation, Escherichia coli genetics, Escherichia coli metabolism, Laccase metabolism, Bacillus genetics
- Abstract
Laccases are multi-copper oxidases and found in ligninolytic bacteria catalyzing the oxidation of both phenolic and non-phenolic compounds, however its application in lignin degradation suffers due to low oxidation rate, which have intensified the search for new laccases. In the present study, spore coat A protein (CotA) encoding gene having laccase like activity from Bacillus altitudinis SL7 (CotA-SL7) was cloned and expressed in Escherichia coli. The purified CotA-SL7 was active at wide range of temperature and pH with optimum activity at 55 °C and pH 5.0. The kinetic parameters of CotA-SL7 was determined with K
m , Vmax , and kcat values 0.4 mM, 2777 μmol/min/mg, and 5194 s-1 , respectively. Molecular docking revealed the presence of Pro, Phe, Asp, Asn, His, and Ile residues at the active site taking part in the oxidation of ABTS. The purified CotA-SL7 reduced lignin contents by 31 % and changes in lignin structure were analyzed through fourier transformed infrared spectroscopy (FTIR), scanning electron microsscopy (SEM) and gas chromatography mass-spectrometry (GC-MS). The appearance of low molecular size compounds clearly indicates the cleavage of lignin polymer and opening of the benzene ring by purified CotA-SL7. Thus, high catalytic efficiency of CotA-SL7 makes it a suitable bio-catalyst for remediation of lignin contaminated wastewater from pulp and paper industries with clear insights into lignin degradation at molecular level., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)- Published
- 2024
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