Production of multiple xylanolytic and cellulolytic enzymes by thermophilic fungus Myceliophthora sp. IMI 387099

Badhan, Ajay; Chadha, Bhupinder Singh; Kaur, Jasweer; Saini, Harvinder Singh; Bhat, M. K.

doi:10.1016/j.biortech.2006.02.009

Cited by 156 publications

(88 citation statements)

References 19 publications

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“…The BG activity was assayed by measuring the increase in absorbance at 400 nm resulting from the release of p-nitrophenol from p-nitrophenyl-␤-glucoside (pNPG) (27). The reaction mixture (0.5 ml) contained 0.2 g of enzyme except the mutant delta-L3 (20 g), and 50 mmol liter Ϫ1 phosphate buffer (pH 6.5) with 5 mmol liter Ϫ1 pNPG (final concentration).…”

Section: Methodsmentioning

confidence: 99%

Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus

Miao

Hou

Fan

et al. 2016

Appl Environ Microbiol

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bPsychrophilic enzymes play crucial roles in cold adaptation of microbes and provide useful models for studies of protein evolution, folding, and dynamic properties. We examined the crystal structure (2.2-Å resolution) of the psychrophilic ␤-glucosidase BglU, a member of the glycosyl hydrolase 1 (GH1) enzyme family found in the cold-adapted bacterium Micrococcus antarcticus. Structural comparison and sequence alignment between BglU and its mesophilic and thermophilic counterpart enzymes (BglB and GlyTn, respectively) revealed two notable features distinct to BglU: (i) a unique long-loop L3 (35 versus 7 amino acids in others) involved in substrate binding and (ii) a unique amino acid, His299 (Tyr in others), involved in the stabilization of an ordered water molecule chain. Shortening of loop L3 to 25 amino acids reduced low-temperature catalytic activity, substrate-binding ability, the optimal temperature, and the melting temperature (T m ). Mutation of His299 to Tyr increased the optimal temperature, the T m , and the catalytic activity. Conversely, mutation of Tyr301 to His in BglB caused a reduction in catalytic activity, thermostability, and the optimal temperature (45 to 35°C). Loop L3 shortening and H299Y substitution jointly restored enzyme activity to the level of BglU, but at moderate temperatures. Our findings indicate that loop L3 controls the level of catalytic activity at low temperatures, residue His299 is responsible for thermolability (particularly heat lability of the active center), and long-loop L3 and His299 are jointly responsible for the psychrophilic properties. The described structural basis for the cold adaptedness of BglU will be helpful for structure-based engineering of new cold-adapted enzymes and for the production of mutants useful in a variety of industrial processes at different temperatures.T he ␤-glucosidases (BGs; ␤-D-glucoside glycohydrolases, EC 3.2.1.21) are a widely occurring group of enzymes that cleave the carbohydrate moiety of short-chain oligosaccharides (two to six degrees of polymerization), alkyl, and aryl ␤-glucosides (1, 2). BGs have been classified into 135 glycoside hydrolase (GH) families, based on amino acid sequence similarity. GHs can also be classified into two major types, retaining and inverting enzymes, according to changes in anomeric configuration during hydrolytic reactions. Early studies of BGs were focused on their role in degrading the plant polymers cellulose and xylan (3, 4). More recently, these enzymes have gained commercial significance because of their biotechnological application in processes related to preparation of plant-based foods, e.g., conversion of phytoestrogen glucosides in fruits and vegetables to aglycone moieties, detoxification of cassava, and degradation of bitter compounds in citrus fruit juices and unripe olives (5, 6). Many mesophilic and thermophilic BGs have been cloned, purified, and characterized during the past 2 decades (5, 7-10). In contrast to mesophilic or thermophilic homologues, BGs from organisms adapted to cold...

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Section: Methodsmentioning

confidence: 99%

Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus

Miao

Hou

Fan

et al. 2016

Appl Environ Microbiol

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“…The xylanase activity was comparable to that obtained from Myceliophthora sp IMI387099 (900 U g -1 ) and Fusarium oxysporum (1840 U g -1 ) [4,23].…”

Section: Production Of Xylanase and Cellulase (Fpase) By The Isolatedsupporting

confidence: 70%

“…As endo- (1,4) (RALET et al, 1994). A presença da enzima ferruloil esterase é um fator importante no aumento das taxas de degradação da biomassa lignocelulósica para conversão em bioenergia e produção de polpa e papel (VRIES et al, 2002).…”

Section: Celulases Hemicelulases E Pectinasesunclassified

“…Many microorganisms are able to produce enzymatic complexes that degrade cellulose, hemicellulose and lignin of plant cell walls, releasing sugars that have applications in subsequent fermentation processes for obtainment of products with high economical value like bioethanol [4]. However, the cost of enzymes production hinders its application on industrial scale [5,6,7].…”

Section: Hidrólise Enzimática Da Biomassa Lignocelulósicamentioning

confidence: 99%

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Isolamento de fungos termofílicos produtores de celulases, xilanases e ferruloil esterase para bioconversão de bagaço de cana de açúcar em açúcares fermentescíveis

Moretti¹

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À Drª Daniela Alonso Bocchini-Martins, pela co-orientação, esclarecimento de dúvidas e parceria na realização dos experimentos.Ao Profº. Drº. Maurício Boscolo, pelo apoio incondicional durante a realização deste projeto, por emprestar seu laboratório e pelas dúvidas esclarecidas.Ao Profº. Drº. Roberto da Silva, pelo esclarecimento de dúvidas.À Drª Lara Durães Sette e ao Drº Andre Rodrigues, pela disposição na identificação dos microrganismos isolados durante a realização da primeira etapa do projeto. À Andréia Jacomassi, pela sincera amizade e companheirismo durante as viagens para realização das disciplinas.Aos meus colegas e amigos dentro e fora do laboratório Ariani, Carol Bezerra, Barbara, Barbara Bonini, Gisele, Larissa, Tiago, Tássia, Rodolfo, Lilian, André, Milla, Ana Flávia. Especialmente aqueles com quem convivi por mais tempo Fabiana, Aline, Carol Merheb, Ellen, Ricardo, Moisés, Natalia, Lívia, Marcelo e Ana Lúcia, pela ajuda, incentivo e momentos felizes nos últimos anos.Ao CNPq pela concessão de bolsa.A CAPES e FAPESP pelo suporte financeiro.À Deus, acima de tudo! A todos que de alguma forma contribuíram para realização deste projeto. , quando cultivados por fermentação em estado sólido (FES) em mistura de bagaçode cana e farelo de trigo (1:1). As produções máximas de xilanase (7237,9 U/g de substrato) e endoglucanase (46,2 U/g de substrato) por A. fumigatus M.7.1 foram observadas pelo cultivo do fungo em palha de milho e farelo de trigo (9:1 p/p) e bagaço de cana e farelo de trigo (9:1 p/p), respectivamente. Em relação ao isolado Myceliophthora sp M.7.7, os picos de produção enzimático produzido por Myceliophthora sp M.7.7, havendo a liberação de 0,5 mg/mL de açúcar redutor. Os resultados de peso seco após a hidrólise não foram significativos, chegando no máximo 10% de perda da massa inicial. Nas analise por HPAEC-PAD foi possível identificar 6 carboidratos (glicose, xilose, celobiose, xilobiose, arabinose e galactose) nos hidrolisados de A. fumigatus M.7.1 e Myceliophthora sp M.7.7. A endoglucanase de ambos microrganismo e a endoxilanase e β-xilosidase de A. fumigatus M.7.1 não sofrem efeito inibitório pela xilose e glicose, quando estes são adicionados na mistura de reação, enquanto que ambas β-glucosidase e a xilanase de Myceliophothora sp. M.7.7 perderam 60% e 40% da atividade inicial em 20 mM de glicose e 8 mM de xilose, respectivamente.Palavras-chave: bagaço de cana, fungo termofílico, fermentação estado sólido, hemicelulases, celulases, pré tratamento, hidrólise enzimática. ABSTRACTThe microorganisms A. fumigatus M.7.1 and Myceliophthora SP M.7.7 were the best producers of FPase (0,8 and 2,0 U/g of substrate) and xylanase (1040 and 1292 U/g of substrate) of the 27 isolated microorganisms, when cultivated by solid state fermentation (SSF) in a mixture of cane bagasse and wheat bran (1:1). The greatest production of xylanase (7237,9 U/g of substrate) and endoglucanase (46,2 U/g of substrate) by A. fumigatus M.7.1were noted by the fungi cultivation in corn straw and wheat bran (9:1 p/p) and cane...

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“…Four species, M. thermo-phila, M. heterothallica, M. hinnulea, and M. fergusii, have been described as thermophilic based on their optimal growth at 45°C and were suggested as producers of industrially interesting enzymes with a stability up to 70°C (2,14). M. thermophila has been extensively described as a producer of thermostable enzymes, such as amylase (17), keratinase (18), laccase (19)(20)(21), cellulase (22)(23)(24), and aldonolactonase (25), and its genome has been completely sequenced (6). Myceliophthora species can also hydrolyze and grow efficiently on plant substrates (14,26).…”

mentioning

confidence: 99%

Efficient Plant Biomass Degradation by Thermophilic Fungus Myceliophthora heterothallica

Brink

Muiswinkel

Theelen

et al. 2013

Appl Environ Microbiol

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bRapid and efficient enzymatic degradation of plant biomass into fermentable sugars is a major challenge for the sustainable production of biochemicals and biofuels. Enzymes that are more thermostable (up to 70°C) use shorter reaction times for the complete saccharification of plant polysaccharides compared to hydrolytic enzymes of mesophilic fungi such as Trichoderma and Aspergillus species. The genus Myceliophthora contains four thermophilic fungi producing industrially relevant thermostable enzymes. Within this genus, isolates belonging to M. heterothallica were recently separated from the well-described species M. thermophila. We evaluate here the potential of M. heterothallica isolates to produce efficient enzyme mixtures for biomass degradation. Compared to the other thermophilic Myceliophthora species, isolates belonging to M. heterothallica and M. thermophila grew faster on pretreated spruce, wheat straw, and giant reed. According to their protein profiles and in vitro assays after growth on wheat straw, (hemi-)cellulolytic activities differed strongly between M. thermophila and M. heterothallica isolates. Compared to M. thermophila, M. heterothallica isolates were better in releasing sugars from mildly pretreated wheat straw (with 5% HCl) with a high content of xylan. The high levels of residual xylobiose revealed that enzyme mixtures of Myceliophthora species lack sufficient ␤-xylosidase activity. Sexual crossing of two M. heterothallica showed that progenies had a large genetic and physiological diversity. In the future, this will allow further improvement of the plant biomass-degrading enzyme mixtures of M. heterothallica. Replacing petrochemical-based fuels and chemicals with truly sustainable alternatives requires biological conversion of agricultural waste plant material to fermentable sugars. The enzyme mixtures for the degradation of biomass-derived polysaccharides (e.g., cellulose, hemicellulose, and pectin) are most commonly produced by fungal strains belonging to the genera Trichoderma and Aspergillus (1). However, these mixtures are not sufficient for economically viable production of low-value products such as biofuels. A major hurdle of the enzyme mixtures from these mesophilic ascomycetes is that they are most effective at temperatures around 50°C (2-4). Higher thermostability of enzymes allows saccharification of biomass polysaccharides at elevated temperatures. Consequently, reaction times will shorten drastically, mass transfer will increase, and substrate viscosity will be reduced (5, 6).Another issue is the initial treatment by physical and/or chemical means (e.g., high temperature or acid or base treatment). This pretreatment should preferably be as mild as possible, since it involves undesirable chemicals and/or a high-energy input in the process (7). Unfortunately, current enzyme mixtures are incapable of releasing efficiently all available monomeric sugars from mildly pretreated biomass.These issues can be solved by searching for other plant-biomass degrading fungi that produce e...

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Production of multiple xylanolytic and cellulolytic enzymes by thermophilic fungus Myceliophthora sp. IMI 387099

Cited by 156 publications

References 19 publications

Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus

Molecular Structural Basis for the Cold Adaptedness of the Psychrophilic β-Glucosidase BglU in Micrococcus antarcticus

Isolamento de fungos termofílicos produtores de celulases, xilanases e ferruloil esterase para bioconversão de bagaço de cana de açúcar em açúcares fermentescíveis

Efficient Plant Biomass Degradation by Thermophilic Fungus Myceliophthora heterothallica

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