scholarly journals Transcriptomics analysis and co-expression network revealing candidate genes for laccase activity of Lenzites gibbosa

2020 ◽  
Author(s):  
Jie Chen ◽  
Yujie Chi ◽  
Qingquan Zhao ◽  
Xin Hao

Abstract Background Lenzites gibbosa is a common white-rot fungus of Polyporaceae in the cold temperate zone which cause spongy white decay of wood. Results In this study, the lignin degradation pathway of L. gibbosa at 5-time points under wood treatment was studied by RNA-Req technology. A total of 5232 DEGs were identified from 15 libraries. In 0–3 days, the mycelia are in the adaptive stage, and the mycelia began to proliferate within 3–5 days. After 5 days, the number of DGEs decreased significantly, the mycelium growth entered the platform stage, and the life activity was basically stable. In the secondary metabolism, oxidoreductase such as laccase, 2-oxoglutarate-Fe (II) type oxidoreductase, peroxisomal hydratase-dehydrogenase, dual-functional monooxygenase dominated and increased steadily, and manganese peroxidase appeared in the middle stage. With the accumulation of lignin intermediate products, P450 and ABC transporters were from the inhibition to the activation. Weighted gene co-expression network analysis (WGCNA) showed that among the 24 modules 6 modules were significantly correlated with laccase activity and the most correlated were turquoise and blue module. The central hub genes were also identified, including gene_7458, gene_61, gene_7458, gene_1741, gene_11087 which were consistent with the DGEs. These genes have high connectivity, module membership, and gene significance in the module. The enrichment analysis of GO and KEGG pathway indicated that the genes involved in cell cycle, citrate cycle (TCA cycle), nicotinate and nicotinamide metabolism, mitochondrial outer membrane, succinate dehydrogenase, carboxypeptidase and exopeptidase activity, flavin adenine dinucleotide binding, oxidoreductase activity, acting on the CH-CH group of donors, quinone or related compound as acceptor pathway were highly related to laccase synthesis pathway. Construction of gene co-expression network and hypothetical L. gibbosa laccase synthesis pathway. Conclusion This study focused on the screening of L. gibbosa degradation of lignin-related genes. And, this is the first study reporting co-expression patterns of a gene network in L. gibbosa laccase activity after wood treatment which is helpful to understand the synthesis pathway of laccase and improve the activity of laccase, which can be used to increase the rate of lignin degradation by L. gibbosa in the further.

1998 ◽  
Vol 44 (7) ◽  
pp. 676-680 ◽  
Author(s):  
Orly Ardon ◽  
Zohar Kerem ◽  
Yitzhak Hadar

The white rot fungus Pleurotus ostreatus was grown in a chemically defined solid state fermentation system amended with cotton stalk extract (CSE).Treated cultures exhibited increased laccase activity as well as enhanced lignin mineralization. Mineralization of [14C]lignin initialized 4 days earlier in CSE-supplemented cultures than in control cultures. Total mineralization in the first 16 days was 15% in the CSE-treated cultures, compared with only 7% in the controls. Cotton stalk extract also contained compounds that serve as substrates for laccase purified from P. ostreatus as shown by oxygen consumption, as well as changes in the UV–visible spectrum.Key words: cotton, Pleurotusostreatus, white rot, laccase, lignin biodegradation.


Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 468
Author(s):  
Anna Pawlik ◽  
Beata Ciołek ◽  
Justyna Sulej ◽  
Andrzej Mazur ◽  
Przemysław Grela ◽  
...  

A white rot fungus Cerrena unicolor has been identified as an important source of laccase, unfortunately regulation of this enzyme genes expression is poorly understood. Using 1D and 2D PAGE and LC-MS/MS, laccase isoenzymes were investigated in the liquid filtrate of C. unicolor culture. The level of expression of laccase genes was measured using qPCR. The elevated concentrations of copper and manganese in the medium caused greatest change in genes expression and three laccase transcripts were significantly affected after culture temperature was decreased from 28 to 4 °C or increased to 40 °C. The small differences in the PAGE band intensities of individual laccase proteins were also observed, indicating that given compound affect particular laccase’s transcript. Analyses of laccase-specific activity, at all tested conditions, showed the increased activities as compared to the control, suggesting that enzyme is regulated at the post-translational stage. We observed that the aspartic protease purified from C. unicolor, significantly stimulate laccase activity. Moreover, electrochemical analysis of protease-treated laccase sample had 5 times higher redox peaks. The obtained results indicate that laccases released by C. unicolor are regulated at transcriptional, translational, and at the post-translational steps of gene expression helping fungus adapt to the environmental changes.


Author(s):  
Johann Hess ◽  
Christian Leitner ◽  
Christiane Galhaup ◽  
Klaus D. Kulbe ◽  
Barbara Hinterstoisser ◽  
...  

2020 ◽  
Author(s):  
Jianqiao Wang ◽  
Tomohiro Suzuki ◽  
Hideo Dohra ◽  
Toshio Mori ◽  
Hirokazu Kawagishi ◽  
...  

Abstract Background Lignocellulosic biomass is an organic matrix composed of cellulose, hemicellulose, and lignin. In nature, lignin degradation by basidiomycetes is the key step in lignocellulose decay. The white-rot fungus Phanerochaete sordida YK-624 (YK-624) has been extensively studied due to its high lignin degradation ability. In our previous study, it was demonstrated that YK-624 can secrete lignin peroxidase and manganese peroxidase for lignin degradation. However, the underlying mechanism for lignin degradation by YK-624 remains unknown.Results Here, we analyzed YK-624 gene expression following growth under ligninolytic and nonligninolytic conditions and compared the differentially expressed genes in YK-624 to those in the model white-rot fungus P. chrysosporium by next-generation sequencing. More ligninolytic enzymes and lignin-degrading auxiliary enzymes were upregulated in YK-624. This might explain the high degradation efficiency of YK-624. In addition, the genes involved in energy metabolism pathways, such as the TCA cycle, oxidative phosphorylation, lipid metabolism, carbon metabolism and glycolysis, were upregulated under ligninolytic conditions in YK-624.Conclusions In the present study, the first differential gene expression analysis of YK-624 under ligninolytic and nonligninolytic conditions was reported. The results obtained in this study indicated that YK-624 produces more energy- and lignin-degrading enzymes for more efficient lignin biodegradation.


2018 ◽  
Vol 84 (11) ◽  
Author(s):  
Sara Casado López ◽  
Mao Peng ◽  
Tedros Yonatan Issak ◽  
Paul Daly ◽  
Ronald P. de Vries ◽  
...  

ABSTRACTFungi can decompose plant biomass into small oligo- and monosaccharides to be used as carbon sources. Some of these small molecules may induce metabolic pathways and the production of extracellular enzymes targeted for degradation of plant cell wall polymers. Despite extensive studies in ascomycete fungi, little is known about the nature of inducers for the lignocellulolytic systems of basidiomycetes. In this study, we analyzed six sugars known to induce the expression of lignocellulolytic genes in ascomycetes for their role as inducers in the basidiomycete white-rot fungusDichomitus squalensusing a transcriptomic approach. This identified cellobiose andl-rhamnose as the main inducers of cellulolytic and pectinolytic genes, respectively, ofD. squalens. Our results also identified differences in gene expression patterns between dikaryotic and monokaryotic strains ofD. squalenscultivated on plant biomass-derived monosaccharides and the disaccharide cellobiose. This suggests that despite conservation of the induction between these two genetic forms ofD. squalens, the fine-tuning in the gene regulation of lignocellulose conversion is differently organized in these strains.IMPORTANCEWood-decomposing basidiomycete fungi have a major role in the global carbon cycle and are promising candidates for lignocellulosic biorefinery applications. However, information on which components trigger enzyme production is currently lacking, which is crucial for the efficient use of these fungi in biotechnology. In this study, transcriptomes of the white-rot fungusDichomitus squalensfrom plant biomass-derived monosaccharide and cellobiose cultures were studied to identify compounds that induce the expression of genes involved in plant biomass degradation.


2013 ◽  
Vol 133 ◽  
pp. 142-149 ◽  
Author(s):  
Alejandra Parenti ◽  
Elaia Muguerza ◽  
Amaia Redin Iroz ◽  
Alejandra Omarini ◽  
Enma Conde ◽  
...  

Evidence in support of an essential role for H 2 O 2 in lignin degradation by the white-rot fungus Phanerochaete chrysosporium has been presented by several laboratories. H 2 O 2 is formed simultaneously with the ligninolytic system, and when it is degraded by catalase the lignin-degrading capacity is also reduced. We have now identified, purified and characterized a sugar-oxidizing enzyme that produces H 2 O 2 during glucose starvation in P. chrysosporium . The enzyme oxidizes glucose at the 2-carbon position to yield glucosone, but 5-n-gluconolactone and xylose are also oxidized at significant rates. Another H 2 O 2 -producing enzyme in P.chrysosporium , methanol oxidase, has also been identified, purified and characterized in this laboratory. Methanol is formed from the methoxyl groups in lignin. Hydrogen peroxide, necessary for further degradation of lignin, is formed by enzyme-catalysed oxidation of the lignin-derived methanol. Induction and repression of the H 2 O 2 -producing enzymes is discussed, as well as ways for the fungus to control the glucose level in its environment.


2021 ◽  
Author(s):  
Mingwen Zhao ◽  
Jing Zhu ◽  
Shuqi Song ◽  
Lindan Lian ◽  
Liang Shi ◽  
...  

Abstract Ganoderma lucidum is a representative white-rot fungus that has great potential to degrade lignocellulose biomass. Laccase is recognized as a class of the most important lignin-degrading enzymes in G. lucidum. However, the comprehensive regulatory mechanisms of laccase are still lacking. Based on the genome sequence of G. lucidum, 15 laccase genes were identified and their encoding proteins were analyzed in this study. All of the laccase proteins are predicted to be multicopper oxidases with conserved copper-binding domains. Most laccase proteins were secreted enzymes in addition to Lac14 in which the signal peptide could not be predicted. The activity of all laccases showed the highest level at pH 3.0 or pH 7.0, with total laccase activity of approximately 200 U/mg protein. Silencing PacC resulted in a 5.2 fold increase in laccase activity compared with WT. Five laccase genes (lac1, lac6, lac9, lac10 and lac14) showed an increased transcription levels (approximately 1.5-5.6 fold) in the PacC-silenced strains versus that in WT, while other laccase genes were downregulated or unchanged. The extracellular pH value was about 3.1, which was more acidic in the PacC-silenced strains than in the WT (pH 3.5). Moreover, maintaining the fermentation pH resulted in a downregulation of laccase activity which is induced by silencing PacC Our findings indicate that in addition to its function in acidification of environmental pH, PacC plays an important role in regulating laccase activity in fungi.


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