Functional expression and characterization of two laccases from the brown rot Fomitopsis pinicola

0548116 - MBÚ 2022 RIV US eng J - Journal Article
Csarman, F. - Obermann, T. - Zanjko, M. C. - Man, Petr - Halada, Petr - Seiboth, B. - Ludwig, R.
Functional expression and characterization of two laccases from the brown rot Fomitopsis pinicola.
Enzyme and Microbial Technology. Roč. 148, AUG 2021 (2021), č. článku 109801. ISSN 0141-0229. E-ISSN 1879-0909
R&D Projects: GA ČR(CZ) GF16-34818L; GA MŠMT(CZ) ED1.1.00/02.0109
Research Infrastructure: CIISB II - 90127
Institutional support: RVO:61388971
Keywords : Biomass degradation * Brown rot * Fomitopsis pinicola * Laccase * Lignin * Trichoderma reesei
OECD category: Biochemistry and molecular biology
Impact factor: 3.705, year: 2021
Method of publishing: Open access
https://www.sciencedirect.com/science/article/pii/S0141022921000594?via%3Dihub

Laccase is predominantly found in lignin degrading filamentous white rot fungi, where it is involved in the oxidative degradation of this recalcitrant heteropolymer. In brown rot fungi it is much less prevalent: laccases from only a few brown rots have been detected and only two have been characterized. This study tries to understand the role of this ligninolytic enzyme in brown rots by investigating the catalytic properties of laccases secreted by Fomitopsis pinicola FP58527 SS1. When grown on either poplar or spruce wood blocks, several laccases were detected in the secretome. Two of them (FpLcc1 and FpLcc2) were heterologously produced using Trichoderma reesei QM9414 Delta xyr1 as expression host and purified to homogeneity by consecutive steps of hydrophobic interaction, anion exchange and size exclusion chromatography. With the substrates 2,2-azino-bis(3ethylthiazoline-6-sulfonate) (ABTS), 2,6-dimethoxyphenol (2,6-DMP) and guaiacol both laccases showed similar, low pH-optima below 3 for ABTS and 2,6-DMP and at pH 3.5 for guaiacol which is at the acidic end of laccases isolated from white rot fungi. The determined KM values were low while kcat values measured at acidic conditions were comparable to those reported for other laccases from white rot fungi. While both enzymes showed a moderate decrease in activity in the presence of oxalic and citric acid FpLcc2 was activated by acetic acid up to 3.7 times. This activation effect is much more pronounced at pH 5.0 compared to pH 3.0 and could already be observed at a concentration of 1 mM acetic acid.
Permanent Link: http://hdl.handle.net/11104/0324230