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Z Q Liang - One of the best experts on this subject based on the ideXlab platform.
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optimal culture conditions for keratinase production by a novel thermophilic Myceliophthora thermophila strain gzuifr h49 1
Journal of Applied Microbiology, 2011Co-Authors: J D Liang, Y F Han, Jiwei Zhang, Z Q LiangAbstract:Aims: To investigate the effect of medium compositions and culture conditions on keratinase production by a novel thermophilic fungus Myceliophthora thermophila (Apinis) Oorschot strain GZUIFR-H49-1. Methods and Results: The thermophilic strain GZUIFR-H49-1 with keratinolytic ability was characterized and identified as a strain of M. thermophila on the basis of its morphological characters and molecular analysis of ITS1-5.8S-ITS2 rDNA sequence. Among the medium compositions tested, the soluble starch (SS), urea, sodium thiosulfate and CaCl2 were the most effective C-source, N-source, S-source and mineral ion, respectively, by employing the single-factor experiment. The urea and pH value were the significant factors (P < 0·05) for the keratinase production in this experiment condition using Plackett–Burman factorial design. The conditions of keratinase production were further optimized by Box–Behnken design. Consequently, there was a 6·4-fold increase (5100 U l−1) in the keratinase activity than the initial value (800 U l−1) by this optimal process. Conclusions: This study indicated that the optimization design proved a useful and powerful tool for the development of optimal medium compositions and culture conditions. Myceliophthora thermophila strain GZUIFR-H49-1 was a promising fungus strain for keratinase production. Significance and Impact of the Study: This study characterized a novel thermophilic M. thermophila strain GZUIFR-H49-1 with potential applications for keratinase production. These conditions of keratinase production obtained by means of optimization design will be accumulated as potential information for exploration and utilization to the new fungus isolate.
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Optimal culture conditions for keratinase production by a novel thermophilic Myceliophthora thermophila strain GZUIFR‐H49‐1
Journal of applied microbiology, 2011Co-Authors: J D Liang, Y F Han, Jiwei Zhang, Z Q LiangAbstract:Aims: To investigate the effect of medium compositions and culture conditions on keratinase production by a novel thermophilic fungus Myceliophthora thermophila (Apinis) Oorschot strain GZUIFR-H49-1. Methods and Results: The thermophilic strain GZUIFR-H49-1 with keratinolytic ability was characterized and identified as a strain of M. thermophila on the basis of its morphological characters and molecular analysis of ITS1-5.8S-ITS2 rDNA sequence. Among the medium compositions tested, the soluble starch (SS), urea, sodium thiosulfate and CaCl2 were the most effective C-source, N-source, S-source and mineral ion, respectively, by employing the single-factor experiment. The urea and pH value were the significant factors (P
Chaoguang Tian - One of the best experts on this subject based on the ideXlab platform.
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Construction of a new thermophilic fungus Myceliophthora thermophila platform for enzyme production using a versatile 2A peptide strategy combined with efficient CRISPR-Cas9 system.
Biotechnology letters, 2020Co-Authors: Liu Qian, Dongguang Xiao, Wenliang Sun, Li Xiaolin, Chenyang Zhang, Dandan Liu, Chaoguang TianAbstract:To construct a new thermophilic platform for glucoamylase production through 2A peptide strategy combined with CRISPR-Cas9 system using Myceliophthora thermophila as host, thermophilic filamentous fungus with industrial attractiveness to produce enzymes and chemicals from biomass. We adapted the viral 2A peptide approach for M. thermophila and constructed a bicistronic vector for co-expressing two heterologous genes MhglaA and egfp. We obtained positive transformants OE-MhglaA-gfp overexpressing MhGlaA-9 ×His-2A-eGFP through convenient fluorescence screening, western blotting and RT-qPCR. We purified and characterized the recombinant MhGlaA, which exhibited stability in a broader pH range of 3.0–9.0 and thermostable stability at 65 °C, suggesting its potential industrial application. Furthermore, to improve glucoamylase secretion, we genetically engineered the obtained strain OE-MhglaA-gfp through our efficient CRISPR/Cas9 system and generated the quintuple mutant OE-MhglaA-gfpOE-amyRΔalp-1Δres-1Δcre-1, in which protein productivity and amylase activity were increased by approximately 12.0- and 8.2-fold compared with WT. The 2A peptide approach worked well in M. thermophila and can be used to heterologously co-express two different proteins, and thus in combination with efficient CRISPR-Cas system will accelerate establishing hyper-secretion platforms for biotechnological applications.
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Metabolic engineering of the cellulolytic thermophilic fungus Myceliophthora thermophila to produce ethanol from cellobiose.
Biotechnology for biofuels, 2020Co-Authors: Yongli Zhang, Tao Sun, Chaoguang TianAbstract:Cellulosic biomass is a promising resource for bioethanol production. However, various sugars in plant biomass hydrolysates including cellodextrins, cellobiose, glucose, xylose, and arabinose, are poorly fermented by microbes. The commonly used ethanol-producing microbe Saccharomyces cerevisiae can usually only utilize glucose, although metabolically engineered strains that utilize xylose have been developed. Direct fermentation of cellobiose could avoid glucose repression during biomass fermentation, but applications of an engineered cellobiose-utilizing S. cerevisiae are still limited because of its long lag phase. Bioethanol production from biomass-derived sugars by a cellulolytic filamentous fungus would have many advantages for the biorefinery industry. We selected Myceliophthora thermophila, a cellulolytic thermophilic filamentous fungus for metabolic engineering to produce ethanol from glucose and cellobiose. Ethanol production was increased by 57% from glucose but not cellobiose after introduction of ScADH1 into the wild-type (WT) strain. Further overexpression of a glucose transporter GLT-1 or the cellodextrin transport system (CDT-1/CDT-2) from N. crassa increased ethanol production by 131% from glucose or by 200% from cellobiose, respectively. Transcriptomic analysis of the engineered cellobiose-utilizing strain and WT when grown on cellobiose showed that genes involved in oxidation–reduction reactions and the stress response were downregulated, whereas those involved in protein biosynthesis were upregulated in this effective ethanol production strain. Turning down the expression of pyc gene results the final engineered strain with the ethanol production was further increased by 23%, reaching up to 11.3 g/L on cellobiose. This is the first attempt to engineer the cellulolytic fungus M. thermophila to produce bioethanol from biomass-derived sugars such as glucose and cellobiose. The ethanol production can be improved about 4 times up to 11 grams per liter on cellobiose after a couple of genetic engineering. These results show that M. thermophila is a promising platform for bioethanol production from cellulosic materials in the future.
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Direct production of commodity chemicals from lignocellulose using Myceliophthora thermophila.
Metabolic engineering, 2019Co-Authors: Liangcai Lin, Tao Sun, Ji Jingxiao, Liu Qian, Chaoguang TianAbstract:Abstract The production of fuels and chemicals from renewable plant biomass has been proposed as a feasible strategy for global sustainable development. However, the economic efficiency of biorefineries is low. Here, through metabolic engineering, Myceliophthora thermophila, a cellulolytic thermophilic fungus, was constructed into a platform that can efficiently convert lignocellulose into important bulk chemicals—four carbon 1, 4-diacids (malic and succinic acid), building blocks for biopolymers—without the need for extra hydrolytic enzymes. Titers of >200 g/L from crystalline cellulose and 110 g/L from plant biomass (corncob) were achieved during fed-batch fermentation. Our study represents a milestone in consolidated bioprocessing technology and offers a new and promising system for the cost-effective production of chemicals and fuels from biomass.
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metabolic engineering of the thermophilic filamentous fungus Myceliophthora thermophila to produce fumaric acid
Biotechnology for Biofuels, 2018Co-Authors: Jingen Li, Bingchen Chen, Shuying Gu, Dongguang Xiao, Chaoguang TianAbstract:Fumaric acid is widely used in food and pharmaceutical industries and is recognized as a versatile industrial chemical feedstock. Increasing concerns about energy and environmental problems have resulted in a focus on fumaric acid production by microbial fermentation via bioconversion of renewable feedstocks. Filamentous fungi are the predominant microorganisms used to produce organic acids, including fumaric acid, and most studies to date have focused on Rhizopus species. Thermophilic filamentous fungi have many advantages for the production of compounds by industrial fermentation. However, no previous studies have focused on fumaric acid production by thermophilic fungi. We explored the feasibility of producing fumarate by metabolically engineering Myceliophthora thermophila using the CRISPR/Cas9 system. Screening of fumarases suggested that the fumarase from Candida krusei was the most suitable for efficient production of fumaric acid in M. thermophila. Introducing the C. krusei fumarase into M. thermophila increased the titer of fumaric acid by threefold. To further increase fumarate production, the intracellular fumarate digestion pathway was disrupted. After deletion of the two fumarate reductase and the mitochondrial fumarase genes of M. thermophila, the resulting strain exhibited a 2.33-fold increase in fumarate titer. Increasing the pool size of malate, the precursor of fumaric acid, significantly increased the final fumaric acid titer. Finally, disruption of the malate–aspartate shuttle increased the intracellular malate content by 2.16-fold and extracellular fumaric acid titer by 42%, compared with that of the parental strain. The strategic metabolic engineering of multiple genes resulted in a final strain that could produce up to 17 g/L fumaric acid from glucose in a fed-batch fermentation process. This is the first metabolic engineering study on the production of fumaric acid by the thermophilic filamentous fungus M. thermophila. This cellulolytic fungal platform provides a promising method for the sustainable and efficient-cost production of fumaric acid from lignocellulose-derived carbon sources in the future.
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Transcriptional analysis of Myceliophthora thermophila on soluble starch and role of regulator AmyR on polysaccharide degradation.
Bioresource technology, 2018Co-Authors: Liu Qian, Wenliang Sun, Min Jiang, Chaoguang TianAbstract:Abstract Thermophilic fungus Myceliophthora thermophila has great capacity for biomass degradation and is an attractive option for use as cell factory to produce chemicals directly from renewable polysaccharides, such as starch, rather than monomer glucose. To date, there has been no transcriptomic analysis of this thermophilic fungus on starch. This study determined the transcriptomic profile of M. thermophila responding to soluble starch and a 342-gene set was identified as a “starch regulon”, including the major amylolytic enzyme (Mycth_72393). Its overexpression led to increased amylase activities on starch by 35%. Furthermore, overexpressing the key amylolytic enzyme regulator AmyR in M. thermophila significantly increased amylase activity by 30%. Deletion of amyR by the CRISPR/Cas9 system led to the relief of carbon catabolite repression and 3-fold increased lignocellulase activities on cellulose. This study will accelerate rational fungal strain engineering for biochemical production from biomass substrates such as raw corn starch and even crop straw.
J D Liang - One of the best experts on this subject based on the ideXlab platform.
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optimal culture conditions for keratinase production by a novel thermophilic Myceliophthora thermophila strain gzuifr h49 1
Journal of Applied Microbiology, 2011Co-Authors: J D Liang, Y F Han, Jiwei Zhang, Z Q LiangAbstract:Aims: To investigate the effect of medium compositions and culture conditions on keratinase production by a novel thermophilic fungus Myceliophthora thermophila (Apinis) Oorschot strain GZUIFR-H49-1. Methods and Results: The thermophilic strain GZUIFR-H49-1 with keratinolytic ability was characterized and identified as a strain of M. thermophila on the basis of its morphological characters and molecular analysis of ITS1-5.8S-ITS2 rDNA sequence. Among the medium compositions tested, the soluble starch (SS), urea, sodium thiosulfate and CaCl2 were the most effective C-source, N-source, S-source and mineral ion, respectively, by employing the single-factor experiment. The urea and pH value were the significant factors (P < 0·05) for the keratinase production in this experiment condition using Plackett–Burman factorial design. The conditions of keratinase production were further optimized by Box–Behnken design. Consequently, there was a 6·4-fold increase (5100 U l−1) in the keratinase activity than the initial value (800 U l−1) by this optimal process. Conclusions: This study indicated that the optimization design proved a useful and powerful tool for the development of optimal medium compositions and culture conditions. Myceliophthora thermophila strain GZUIFR-H49-1 was a promising fungus strain for keratinase production. Significance and Impact of the Study: This study characterized a novel thermophilic M. thermophila strain GZUIFR-H49-1 with potential applications for keratinase production. These conditions of keratinase production obtained by means of optimization design will be accumulated as potential information for exploration and utilization to the new fungus isolate.
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Optimal culture conditions for keratinase production by a novel thermophilic Myceliophthora thermophila strain GZUIFR‐H49‐1
Journal of applied microbiology, 2011Co-Authors: J D Liang, Y F Han, Jiwei Zhang, Z Q LiangAbstract:Aims: To investigate the effect of medium compositions and culture conditions on keratinase production by a novel thermophilic fungus Myceliophthora thermophila (Apinis) Oorschot strain GZUIFR-H49-1. Methods and Results: The thermophilic strain GZUIFR-H49-1 with keratinolytic ability was characterized and identified as a strain of M. thermophila on the basis of its morphological characters and molecular analysis of ITS1-5.8S-ITS2 rDNA sequence. Among the medium compositions tested, the soluble starch (SS), urea, sodium thiosulfate and CaCl2 were the most effective C-source, N-source, S-source and mineral ion, respectively, by employing the single-factor experiment. The urea and pH value were the significant factors (P
Paul Christakopoulos - One of the best experts on this subject based on the ideXlab platform.
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Evolution of the feruloyl esterase MtFae1a from Myceliophthora thermophila towards improved catalysts for antioxidants synthesis.
Applied microbiology and biotechnology, 2018Co-Authors: Simona Varriale, Paul Christakopoulos, Io Antonopoulou, Gabriella Cerullo, Peter Jütten, Alexander Piechot, Ulrika Rova, Thierry Tron, Régis Fauré, Joana L. A. BrásAbstract:The chemical syntheses currently employed for industrial purposes, including in the manufacture of cosmetics, present limitations such as unwanted side reactions and the need for harsh chemical reaction conditions. In order to overcome these drawbacks, novel enzymes are developed to catalyze the targeted bioconversions. In the present study, a methodology for the construction and the automated screening of evolved variants library of a Type B feruloyl esterase from Myceliophthora thermophila (MtFae1a) was developed and applied to generation of 30,000 mutants and their screening for selecting the variants with higher activity than the wild-type enzyme. The library was generated by error-prone PCR of mtfae1a cDNA and expressed in Saccharomyces cerevisiae. Screening for extracellular enzymatic activity towards 4-nitrocatechol-1-yl ferulate, a new substrate developed ad hoc for high-throughput assays of feruloyl esterases, led to the selection of 30 improved enzyme variants. The best four variants and the wild-type MtFae1a were investigated in docking experiments with hydroxycinnamic acid esters using a model of 3D structure of MtFae1a. These variants were also used as biocatalysts in transesterification reactions leading to different target products in detergentless microemulsions and showed enhanced synthetic activities, although the screening strategy had been based on improved hydrolytic activity.
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A thermostable GH26 endo-β-mannanase from Myceliophthora thermophila capable of enhancing lignocellulose degradation.
Applied microbiology and biotechnology, 2016Co-Authors: Constantinos Katsimpouras, Maria Dimarogona, Paul Christakopoulos, Pericles Petropoulos, Evangelos TopakasAbstract:The endomannanase gene em26a from the thermophilic fungus Myceliophthora thermophila, belonging to the glycoside hydrolase family 26, was functionally expressed in the methylotrophic yeast Pichia pastoris. The putative endomannanase, dubbed MtMan26A, was purified to homogeneity (60 kDa) and subsequently characterized. The optimum pH and temperature for the enzymatic activity of MtMan26A were 6.0 and 60 °C, respectively. MtMan26A showed high specific activity against konjac glucomannan and carob galactomannan, while it also exhibited high thermal stability with a half-life of 14.4 h at 60 °C. Thermostability is of great importance, especially in industrial processes where harsh conditions are employed. With the aim of better understanding its structure–function relationships, a homology model of MtMan26A was constructed, based on the crystallographic structure of a close homologue. Finally, the addition of MtMan26A as a supplement to the commercial enzyme mixture Celluclast® 1.5 L and Novozyme® 188 resulted in enhanced enzymatic hydrolysis of pretreated beechwood sawdust, improving the release of total reducing sugars and glucose by 13 and 12 %, respectively.
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Bioconversion of Biomass-Derived Phenols Catalyzed by Myceliophthora thermophila Laccase.
Molecules (Basel Switzerland), 2016Co-Authors: Anastasia Zerva, Paul Christakopoulos, Nikolaos Manos, Stamatina Vouyiouka, Evangelos TopakasAbstract:Biomass-derived phenols have recently arisen as an attractive alternative for building blocks to be used in synthetic applications, due to their widespread availability as an abundant renewable resource. In the present paper, commercial laccase from the thermophilic fungus Myceliophthora thermophila was used to bioconvert phenol monomers, namely catechol, pyrogallol and gallic acid in water. The resulting products from catechol and gallic acid were polymers that were partially characterized in respect to their optical and thermal properties, and their average molecular weight was estimated via solution viscosity measurements and GPC. FT-IR and 1H-NMR data suggest that phenol monomers are connected with ether or C–C bonds depending on the starting monomer, while the achieved molecular weight of polycatechol is found higher than the corresponding poly(gallic acid). On the other hand, under the same condition, pyrogallol was dimerized in a pure red crystalline compound and its structure was confirmed by 1H-NMR as purpurogallin. The herein studied green synthesis of enzymatically synthesized phenol polymers or biological active compounds could be exploited as an alternative synthetic route targeting a variety of applications.
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Characterization and application of a novel class II thermophilic peroxidase from Myceliophthora thermophila in biosynthesis of polycatechol.
Enzyme and microbial technology, 2015Co-Authors: Anastasia Zerva, Paul Christakopoulos, Evangelos TopakasAbstract:A peroxidase from the thermophilic fungus Myceliophthora thermophila that belongs to ascomycete Class II based on PeroxiBase classification was functionally expressed in methylotrophic yeast Pichia pastoris. The putative peroxidase from the genomic DNA was successfully cloned in P. pastoris X-33 under the transcriptional control of the alcohol oxidase (AOX1) promoter. The heterologous production was greatly enhanced by the addition of hemin with a titer of 0.41 U mL(-1) peroxidase activity at the second day of incubation. The recombinant enzyme was purified to homogeneity (50 kDa) and characterized using a series of phenolic substrates that indicated similar characteristics with those of generic peroxidases. In addition, the enzyme was found thermostable, retaining its activity for temperatures up to 60 °C after eight hours incubation. Moreover, the enzyme displayed remarkable H2O2 stability, retaining more than 80% of its initial activity after 24h incubation in 5000-fold molar excess of H2O2. The ability of the peroxidase to polymerize catechol at high superoxide concentrations, together with its high thermostability and substrate specificity, indicate a potential commercial significance of the enzyme.
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Genomic insights into the fungal lignocellulolytic system of Myceliophthora thermophila.
Frontiers in microbiology, 2014Co-Authors: Anthi Karnaouri, Evangelos Topakas, Io Antonopoulou, Paul ChristakopoulosAbstract:The microbial conversion of solid cellulosic biomass to liquid biofuels may provide a renewable energy source for transportation fuels. Cellulolytic fungi represent a promising group of organisms, as they have evolved complex systems for adaptation to their natural habitat. The filamentous fungus Myceliophthora thermophila constitutes an exceptionally powerful cellulolytic microorganism that synthesizes a complete set of enzymes necessary for the breakdown of plant cell wall. The genome of this fungus has been recently sequenced and annotated, allowing systematic examination and identification of enzymes required for the degradation of lignocellulosic biomass. The genomic analysis revealed the existence of an expanded enzymatic repertoire including numerous cellulases, hemicellulases and enzymes with auxiliary activities, covering the most of the recognized CAZy families. Most of them were predicted to possess a secretion signal and undergo through post translational glycosylation modifications. These data offer a better understanding of activities embedded in fungal lignocellulose decomposition mechanisms and suggest that M. thermophila could be made usable as an industrial production host for cellulolytic and hemicellulolytic enzymes.
Evangelos Topakas - One of the best experts on this subject based on the ideXlab platform.
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Kinetic and amperometric study of the MtPerII peroxidase isolated from the ascomycete fungus Myceliophthora thermophila.
Bioelectrochemistry (Amsterdam Netherlands), 2017Co-Authors: D. Zouraris, Evangelos Topakas, Anastasia Zerva, Antonis KarantonisAbstract:Abstract The enzyme Mt PerII is a new peroxidase which has been isolated only recently from fungus Myceliophthora thermophila and has significant thermostability and stability at high H 2 O 2 concentrations. In the present work, an electrochemical kinetic study, based on cyclic voltammetry, is performed for the first time for the catalytic decomposition of H 2 O 2 by Mt PerII, at 18 °C. Leuco methylene blue (LMB) is used as a mediator and the catalytic and Michaelis constants are determined, assuming a Michaelis-Menten mechanism. Experimental evidence suggest the absence of inhibition by H 2 O 2 , for concentrations up to 16 mM, and increasing catalytic activity for temperatures up to 50 °C. Moreover, a modified electrode is constructed, by attempting the entrapment of Mt PerII on a dodecanothiol self-assembled monolayer on gold. The modified electrode is studied chronoamperometrically in solutions containing methylene blue mediator and different concentrations of H 2 O 2 . It is shown that adsorbed Mt PerII retains its activity and the modified electrode exhibits a considerably high linear region for the detection of H 2 O 2 . The experimental findings indicate that Mt PerII is a new candidate for analytical and industrial applications.
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A thermostable GH26 endo-β-mannanase from Myceliophthora thermophila capable of enhancing lignocellulose degradation.
Applied microbiology and biotechnology, 2016Co-Authors: Constantinos Katsimpouras, Maria Dimarogona, Paul Christakopoulos, Pericles Petropoulos, Evangelos TopakasAbstract:The endomannanase gene em26a from the thermophilic fungus Myceliophthora thermophila, belonging to the glycoside hydrolase family 26, was functionally expressed in the methylotrophic yeast Pichia pastoris. The putative endomannanase, dubbed MtMan26A, was purified to homogeneity (60 kDa) and subsequently characterized. The optimum pH and temperature for the enzymatic activity of MtMan26A were 6.0 and 60 °C, respectively. MtMan26A showed high specific activity against konjac glucomannan and carob galactomannan, while it also exhibited high thermal stability with a half-life of 14.4 h at 60 °C. Thermostability is of great importance, especially in industrial processes where harsh conditions are employed. With the aim of better understanding its structure–function relationships, a homology model of MtMan26A was constructed, based on the crystallographic structure of a close homologue. Finally, the addition of MtMan26A as a supplement to the commercial enzyme mixture Celluclast® 1.5 L and Novozyme® 188 resulted in enhanced enzymatic hydrolysis of pretreated beechwood sawdust, improving the release of total reducing sugars and glucose by 13 and 12 %, respectively.
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Bioconversion of Biomass-Derived Phenols Catalyzed by Myceliophthora thermophila Laccase.
Molecules (Basel Switzerland), 2016Co-Authors: Anastasia Zerva, Paul Christakopoulos, Nikolaos Manos, Stamatina Vouyiouka, Evangelos TopakasAbstract:Biomass-derived phenols have recently arisen as an attractive alternative for building blocks to be used in synthetic applications, due to their widespread availability as an abundant renewable resource. In the present paper, commercial laccase from the thermophilic fungus Myceliophthora thermophila was used to bioconvert phenol monomers, namely catechol, pyrogallol and gallic acid in water. The resulting products from catechol and gallic acid were polymers that were partially characterized in respect to their optical and thermal properties, and their average molecular weight was estimated via solution viscosity measurements and GPC. FT-IR and 1H-NMR data suggest that phenol monomers are connected with ether or C–C bonds depending on the starting monomer, while the achieved molecular weight of polycatechol is found higher than the corresponding poly(gallic acid). On the other hand, under the same condition, pyrogallol was dimerized in a pure red crystalline compound and its structure was confirmed by 1H-NMR as purpurogallin. The herein studied green synthesis of enzymatically synthesized phenol polymers or biological active compounds could be exploited as an alternative synthetic route targeting a variety of applications.
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Characterization and application of a novel class II thermophilic peroxidase from Myceliophthora thermophila in biosynthesis of polycatechol.
Enzyme and microbial technology, 2015Co-Authors: Anastasia Zerva, Paul Christakopoulos, Evangelos TopakasAbstract:A peroxidase from the thermophilic fungus Myceliophthora thermophila that belongs to ascomycete Class II based on PeroxiBase classification was functionally expressed in methylotrophic yeast Pichia pastoris. The putative peroxidase from the genomic DNA was successfully cloned in P. pastoris X-33 under the transcriptional control of the alcohol oxidase (AOX1) promoter. The heterologous production was greatly enhanced by the addition of hemin with a titer of 0.41 U mL(-1) peroxidase activity at the second day of incubation. The recombinant enzyme was purified to homogeneity (50 kDa) and characterized using a series of phenolic substrates that indicated similar characteristics with those of generic peroxidases. In addition, the enzyme was found thermostable, retaining its activity for temperatures up to 60 °C after eight hours incubation. Moreover, the enzyme displayed remarkable H2O2 stability, retaining more than 80% of its initial activity after 24h incubation in 5000-fold molar excess of H2O2. The ability of the peroxidase to polymerize catechol at high superoxide concentrations, together with its high thermostability and substrate specificity, indicate a potential commercial significance of the enzyme.
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Genomic insights into the fungal lignocellulolytic system of Myceliophthora thermophila.
Frontiers in microbiology, 2014Co-Authors: Anthi Karnaouri, Evangelos Topakas, Io Antonopoulou, Paul ChristakopoulosAbstract:The microbial conversion of solid cellulosic biomass to liquid biofuels may provide a renewable energy source for transportation fuels. Cellulolytic fungi represent a promising group of organisms, as they have evolved complex systems for adaptation to their natural habitat. The filamentous fungus Myceliophthora thermophila constitutes an exceptionally powerful cellulolytic microorganism that synthesizes a complete set of enzymes necessary for the breakdown of plant cell wall. The genome of this fungus has been recently sequenced and annotated, allowing systematic examination and identification of enzymes required for the degradation of lignocellulosic biomass. The genomic analysis revealed the existence of an expanded enzymatic repertoire including numerous cellulases, hemicellulases and enzymes with auxiliary activities, covering the most of the recognized CAZy families. Most of them were predicted to possess a secretion signal and undergo through post translational glycosylation modifications. These data offer a better understanding of activities embedded in fungal lignocellulose decomposition mechanisms and suggest that M. thermophila could be made usable as an industrial production host for cellulolytic and hemicellulolytic enzymes.
