Biological pretreatment of rice husks with the white-rot fungus pleurotus ostreatus: the role of laccase activity

2021 ◽  
Author(s):  
◽  
Dinary Durán Sequeda
Keyword(s):  
Laccase Activity ◽  
Culture Media ◽  
White Rot ◽  
White Rot Fungus ◽  
Rice Husks ◽  
Media Composition ◽  
Biological Pretreatment ◽  
Submerged Cultures ◽  
Nutritional Conditions

The main objective of this study was to determine the influence of the composition of the culture medium and lignocellulosic compounds on the secretion of laccase enzymes by P. ostreatus in submerged cultures. These studies were done using a statistical and systematic approach that allowed the control of the culture media composition. The optimal nutritional conditions were found that simultaneously increased fungal growth and laccase activity in the absence and presence of copper sulfate, a recognized inducer of laccase. Under these conditions, the biochemical aspects of transcripts in P. ostreatus related to laccase secretion were evaluated , which revealed the participation of membrane transporters with high affinity for copper (CTRs) as intermediate candidates for the regulation of three laccase genes, lacc2, lacc6, and lacc10. Moreover, the evaluation of the results of the culture media composition suggests that the regulation of these transporters is closely linked to sufficient nutritional conditions in carbon and nitrogen, with central participation of the metabolism of organic nitrogen in this process. With these findings, it was possible to obtain more profound knowledge of the pretreatment of lignocellulosic biomass by P. ostreatus in a submerged culture that was oriented to determine the role of laccase activity in the biological pretreatment of rice husks.

Tannic acid induces transcription of laccase genecglcc1in the white-rot fungusCoriolopsis gallica

2002 ◽  
Vol 48 (12) ◽  
pp. 1041-1047 ◽  
Author(s):  
José M Carbajo ◽  
Howard Junca ◽  
María C Terrón ◽  
Tania González ◽  
Susana Yagüe ◽  
...  
Keyword(s):  
Tannic Acid ◽  
Laccase Activity ◽  
Culture Media ◽  
Environmental Pollutants ◽  
White Rot Fungi ◽  
Extracellular Enzyme ◽  
White Rot ◽  
Laccase Gene ◽  
Extracellular Laccase

Laccase, a phenoloxidase enzyme secreted by white-rot fungi, has a significant role in the degradation of lignin and environmental pollutants. Coriolopsis gallica is a ligninolytic basidiomycete that produces high levels of this extracellular enzyme. A laccase gene cglcc1 from this fungus has been cloned and sequenced. The capacity of C. gallica to efficiently degrade polyphenols has been successfully applied in our laboratory to the biotreatment and decolorization of several industrial wastewaters. This study focused on the effect of tannic acid, a natural compound widely distributed in plants, on the production of laccase activity by C. gallica. Our results showed an evident increase of extracellular laccase levels when C. gallica was grown in the presence of tannic acid. Concentrations of 50 and 100 μM of this compound increased laccase activity when compared with control samples grown without tannic acid. In addition, we found an increase in laccase transcript levels in C. gallica grown in culture media supplemented with tannic acid. The role of tannic acid was shown to be an inductor of laccase activity in this fungus, due to the enhancement of expression of the laccase gene at the transcriptional level.Key words: laccase, tannic acid, Coriolopsis gallica, induction, gene transcription.

Synergistic Methodology Based on Ion Exchange and Biodegradation Mechanisms Applied for Metal Complex Dye Removal from Waste Waters

2018 ◽  
Vol 69 (1) ◽  
pp. 38-44
Author(s):  
Nicoleta Mirela Marin ◽  
Olga Tiron ◽  
Luoana Florentina Pascu ◽  
Mihaela Costache ◽  
Mihai Nita Lazar ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Synergistic Effects ◽  
Freundlich Isotherm ◽  
White Rot ◽  
White Rot Fungus ◽  
Basic Anion Exchange Resin ◽  
Km Value ◽  
Points Of View ◽  
Basic Anion

This study investigates the synergistic effects of ion exchange and biodegradation methods to remove the Acid Blue 193 also called Gryfalan Navy Blue RL (GNB) dye from wastewater. Ion exchange studies were performed using a strongly basic anion exchange resin Amberlite IRA 400. The equilibrium was characterized by a kinetic and thermodynamic points of view, establishing that the sorption of the GNB dye was subject to the Freundlich isotherm model with R2 = 0.8710. Experimental results showed that the activated resin can removed up to 93.4% when the concentration of dye solution is 5.62�10-2 mM. The biodegradation of the GNB was induced by laccase, an enzyme isolated from white-rot fungus. It was also analyzed the role of pH and dye concentration on GNB biodegradation, so 5�10-2 mM dye had a maximum discoloration efficiency of 82.9% at pH of 4. The laccase showed a very fast and robust activity reaching in a few minutes a Km value of 2.2�10-1mM. In addition, increasing the GNB concentration up to 8�10-1 mM did not triggered a substrat inhibition effect on the laccase activity. Overall, in this study we proposed a mixt physicochemical and biological approach to enhance the GNB removal and biodegradability from the wastewaters and subsequently the environment.

scholarly journals Cerrena unicolor Laccases, Genes Expression and Regulation of Activity

Biomolecules ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 468
Author(s):  
Anna Pawlik ◽  
Beata Ciołek ◽  
Justyna Sulej ◽  
Andrzej Mazur ◽  
Przemysław Grela ◽  
...  
Keyword(s):  
Laccase Activity ◽  
Environmental Changes ◽  
Specific Activity ◽  
Electrochemical Analysis ◽  
White Rot ◽  
White Rot Fungus ◽  
Cerrena Unicolor ◽  
Genes Expression ◽  
Regulation Of Activity ◽  
Laccase Genes

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.

Enhanced Formation of Extracellular Laccase Activity by the White-Rot Fungus Trametes multicolor

2002 ◽  
pp. 229-241 ◽  
Author(s):  
Johann Hess ◽  
Christian Leitner ◽  
Christiane Galhaup ◽  
Klaus D. Kulbe ◽  
Barbara Hinterstoisser ◽  
...  
Keyword(s):  
Laccase Activity ◽  
White Rot ◽  
White Rot Fungus ◽  
Extracellular Laccase ◽  
Trametes Multicolor

scholarly journals Biological Pretreatment of Rubberwood withCeriporiopsis subvermisporafor Enzymatic Hydrolysis and Bioethanol Production

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Forough Nazarpour ◽  
Dzulkefly Kuang Abdullah ◽  
Norhafizah Abdullah ◽  
Nazila Motedayen ◽  
Reza Zamiri
Keyword(s):  
Particle Size ◽  
Enzymatic Hydrolysis ◽  
Raw Material ◽  
White Rot ◽  
White Rot Fungus ◽  
Cellulose Content ◽  
Bioethanol Production ◽  
Biological Pretreatment ◽  
Spectra Analysis ◽  
Alternative Material

Rubberwood (Hevea brasiliensis), a potential raw material for bioethanol production due to its high cellulose content, was used as a novel feedstock for enzymatic hydrolysis and bioethanol production using biological pretreatment. To improve ethanol production, rubberwood was pretreated with white rot fungusCeriporiopsis subvermisporato increase fermentation efficiency. The effects of particle size of rubberwood (1 mm, 0.5 mm, and 0.25 mm) and pretreatment time on the biological pretreatment were first determined by chemical analysis and X-ray diffraction and their best condition obtained with 1 mm particle size and 90 days pretreatment. Further morphological study on rubberwood with 1 mm particle size pretreated by fungus was performed by FT-IR spectra analysis and SEM observation and the result indicated the ability of this fungus for pretreatment. A study on enzymatic hydrolysis resulted in an increased sugar yield of 27.67% as compared with untreated rubberwood (2.88%). The maximum ethanol concentration and yield were 17.9 g/L and 53% yield, respectively, after 120 hours. The results obtained demonstrate that rubberwood pretreated byC. subvermisporacan be used as an alternative material for the enzymatic hydrolysis and bioethanol production.

Enhancement of lignin degradation and laccase activity in Pleurotus ostreatus by cotton stalk extract

1998 ◽  
Vol 44 (7) ◽  
pp. 676-680 ◽  
Author(s):  
Orly Ardon ◽  
Zohar Kerem ◽  
Yitzhak Hadar
Keyword(s):  
Oxygen Consumption ◽  
Pleurotus Ostreatus ◽  
Lignin Degradation ◽  
Laccase Activity ◽  
White Rot ◽  
White Rot Fungus ◽  
Lignin Biodegradation ◽  
Cotton Stalk ◽  
Fermentation System ◽  
Uv Visible

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.

Investigation of the role of 3-hydroxyanthranilic acid in the degradation of lignin by white-rot fungus Pycnoporus cinnabarinus

2001 ◽  
Vol 28 (4-5) ◽  
pp. 301-307 ◽  
Author(s):  
Kaichang Li ◽  
Peter S Horanyi ◽  
Robert Collins ◽  
Robert S Phillips ◽  
Karl-Erik L Eriksson
Keyword(s):  
White Rot ◽  
White Rot Fungus ◽  
Pycnoporus Cinnabarinus ◽  
Hydroxyanthranilic Acid

Induction of laccase activity in the white rot fungus Pleurotus ostreatus using water polluted with wheat straw extracts

2013 ◽  
Vol 133 ◽  
pp. 142-149 ◽  
Author(s):  
Alejandra Parenti ◽  
Elaia Muguerza ◽  
Amaia Redin Iroz ◽  
Alejandra Omarini ◽  
Enma Conde ◽  
...  
Keyword(s):  
Wheat Straw ◽  
Pleurotus Ostreatus ◽  
Laccase Activity ◽  
White Rot ◽  
White Rot Fungus

scholarly journals Improvement of laccase activity by silencing PacC in Ganoderma lucidum

2021 ◽  
Author(s):  
Mingwen Zhao ◽  
Jing Zhu ◽  
Shuqi Song ◽  
Lindan Lian ◽  
Liang Shi ◽  
...  
Keyword(s):  
Ganoderma Lucidum ◽  
Laccase Activity ◽  
Ph Value ◽  
Fold Increase ◽  
White Rot ◽  
White Rot Fungus ◽  
Copper Binding ◽  
Multicopper Oxidases ◽  
Binding Domains ◽  
Laccase Genes

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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