Functional Characterization of Laccase Isozyme (PoLcc1) from the Edible Mushroom <i>Pleurotus ostreatus</i> Involved in Lignin Degradation in Cotton Straw
Fungal laccases play important roles in the degradation of lignocellulose. In this study, the laccase producing cotton straw medium for <i>Pleurotus ostreatus</i> was optimized by single-factor and orthogonal experiments, and to investigate the role of <i>Lacc1</i> gene, one...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2022-11-01
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| Series: | International Journal of Molecular Sciences |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1422-0067/23/21/13545 |
| Summary: | Fungal laccases play important roles in the degradation of lignocellulose. In this study, the laccase producing cotton straw medium for <i>Pleurotus ostreatus</i> was optimized by single-factor and orthogonal experiments, and to investigate the role of <i>Lacc1</i> gene, one of the laccase-encoding genes, in the degradation of cotton straw lignin, an overexpression strain of <i>Lacc1</i> gene was constructed, which was analyzed for the characteristics of lignin degradation. The results demonstrated that the culture conditions with the highest lignin degradation efficiency of the <i>P. ostreatus</i> were the cotton straw particle size of 0.75 mm, a solid–liquid ratio of 1:3 and containing 0.25 g/L of Tween in the medium, as well as an incubation temperature of 26 °C. Two overexpression strains (OE L1-1 and OE L1-4) of <i>Lacc1</i> gene were obtained, and the gene expression increased 12.08- and 33.04-fold, respectively. The results of <sup>1</sup>H-NMR and FTIR analyses of significant changes in lignin structure revealed that <i>Lacc1</i> gene accelerated the degradation of lignin G-units and involved in the cleavage of β-O-4 linkages and the demethylation of lignin units. These findings will help to improve the efficiency of biodelignification and expand our understanding of its mechanism. |
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| ISSN: | 1661-6596 1422-0067 |