Enhanced lignin biodegradation by consortium of white rot fungi: microbial synergistic effects and product mapping

• Main Authors: Cui, T. (Author), Fei, Q. (Author), Guo, H. (Author), Li, C. (Author), Ma, Y. (Author), Tian, H. (Author), Wang, W. (Author), Yuan, B. (Author)
• Format: Article
• Language: English
• Published: BioMed Central Ltd 2021
• Subjects: biodegradation; Biodegradation; biofuel; Biological conversion; biomass; Degradation; Enhanced biodegradation; Enzymatic activities; enzyme activity; Enzyme activity; Fungi; fungus; Gas chromatography; Gas Chromatography; Heteronuclear single-quantum coherences; Laccase; Lenzites betulina; lignin; Lignin; Lignin biodegradation; Ligninolytic enzymes; Lignocellulosic biomass; Manganese compounds; Manganese Compounds; manganese oxide; Manganese peroxidase; Mapping; microbial activity; Phosphorus compounds; Product mapping; Quantum theory; Scanning electron microscopy; Secondary ion mass spectrometry; Synergistic effect; Trametes versicolor; White rot fungi (WRF)
• Online Access: View Fulltext in Publisher

 Background: As one of the major components of lignocellulosic biomass, lignin has been considered as the most abundant renewable aromatic feedstock in the world. Comparing with thermal or catalytic strategies for lignin degradation, biological conversion is a promising approach featuring with mild conditions and diversity, and has received great attention nowadays. Results: In this study, a consortium of white rot fungi composed of Lenzites betulina and Trametes versicolor was employed to enhance the ligninolytic enzyme activity of laccase (Lac) and manganese peroxidase (MnP) under microbial synergism. The maximum enzymatic activity of Lac and MnP was individually 18.06 U mL−1 and 13.58 U mL−1 along with a lignin degradation rate of 50% (wt/wt), which were achieved from batch cultivation of the consortium. The activities of Lac and MnP obtained from the consortium were both improved more than 40%, as compared with monocultures of L. betulina or T. versicolor under the same culture condition. The enhanced biodegradation performance was in accordance with the results observed from scanning electron microscope (SEM) of lignin samples before and after biodegradation, and secondary-ion mass spectrometry (SIMS). Finally, the analysis of heteronuclear single quantum coherence (HSQC) NMR and gas chromatography–mass spectrometry (GC–MS) provided a comprehensive product mapping of the lignin biodegradation, suggesting that the lignin has undergone depolymerization of the macromolecules, side-chain cleavage, and aromatic ring-opening reactions. Conclusions: Our results revealed a considerable escalation on the enzymatic activity obtained in a short period from the cultivation of the L. betulina or T. versicolor due to the enhanced microbial synergistic effects, providing a potential bioconversion route for lignin utilization. © 2021, The Author(s).