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1.
Appl Microbiol Biotechnol ; 108(1): 458, 2024 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-39230670

RESUMEN

The advancement of fungal biocontrol agents depends on replacing cereal grains with low-cost agro-industrial byproducts for their economical mass production and development of stable formulations. We propose an innovative approach to develop a rice flour-based formulation of the beneficial biocontrol agent Trichoderma asperelloides CMAA1584 designed to simulate a micro-bioreactor within the concept of full biorefinery process, affording in situ conidiation, extended shelf-life, and effective control of Sclerotinia sclerotiorum, a devastating pathogen of several dicot agricultural crops worldwide. Rice flour is an inexpensive and underexplored byproduct derived from broken rice after milling, capable of sustaining high yields of conidial production through our optimized fermentation-formulation route. Conidial yield was mainly influenced by nitrogen content (0.1% w/w) added to the rice meal coupled with the fermentor type. Hydrolyzed yeast was the best nitrogen source yielding 2.6 × 109 colony-forming units (CFU)/g within 14 days. Subsequently, GControl, GLecithin, GBreak-Thru, GBentonite, and GOrganic compost+Break-Thru formulations were obtained by extrusion followed by air-drying and further assessed for their potential to induce secondary sporulation in situ, storage stability, and efficacy against Sclerotinia. GControl, GBreak-Thru, GBentonite, and GOrganic compost+Break-Thru stood out with the highest number of CFU after sporulation upon re-hydration on water-agar medium. Shelf-life of formulations GControl and GBentonite remained consistent for > 3 months at ambient temperature, while in GBentonite and GOrganic compost+Break-Thru formulations remained viable for 24 months during refrigerated storage. Formulations exhibited similar efficacy in suppressing the myceliogenic germination of Sclerotinia irrespective of their concentration tested (5 × 104 to 5 × 106 CFU/g of soil), resulting in 79.2 to 93.7% relative inhibition. Noteworthily, all 24-month-old formulations kept under cold storage successfully suppressed sclerotia. This work provides an environmentally friendly bioprocess method using rice flour as the main feedstock to develop waste-free granular formulations of Trichoderma conidia that are effective in suppressing Sclerotinia while also improving biopesticide shelf-life. KEY POINTS: • Innovative "bioreactor-in-a-granule" system for T. asperelloides is devised. • Dry granules of aerial conidia remain highly viable for 24 months at 4 °C. • Effective control of white-mold sclerotia via soil application of Trichoderma-based granules.


Asunto(s)
Ascomicetos , Reactores Biológicos , Fermentación , Oryza , Esporas Fúngicas , Reactores Biológicos/microbiología , Ascomicetos/crecimiento & desarrollo , Ascomicetos/metabolismo , Oryza/microbiología , Esporas Fúngicas/crecimiento & desarrollo , Nitrógeno/metabolismo , Hypocreales/metabolismo , Hypocreales/crecimiento & desarrollo , Agentes de Control Biológico/química , Trichoderma/metabolismo , Trichoderma/crecimiento & desarrollo , Enfermedades de las Plantas/microbiología , Enfermedades de las Plantas/prevención & control
2.
Int J Biol Macromol ; 246: 125646, 2023 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-37394222

RESUMEN

The use of Bacillus as biofertilizer is a sustainable strategy to increase agricultural productivity, but it still requires the development of formulations to protect cells from stressful conditions. Ionotropic gelation using a pectin/starch matrix is a promising encapsulation strategy to achieve this goal. By incorporating additives such as montmorillonite (MMT), attapulgite (ATP), polyethylene glycol (PEG), and carboxymethyl cellulose (CMC), the properties of these encapsulated products could be further improved. In this study, we investigated the influence of these additives on the properties of pectin/starch-based beads for the encapsulation of Bacillus subtilis. FTIR analysis indicated pectin and Ca2+ ions interactions, while the XRD showed good dispersion of clays in the materials. SEM and X-ray microtomography revealed differences in the morphology of the beads due to the use of the additives. The viabilities at the encapsulation were higher than 1010 CFU g-1 for all formulations, with differences in the release profiles. In terms of cell protection, the pectin/starch, pectin/starch-MMT and pectin/starch-CMC formulations showed the highest cell viability after exposure to fungicide, while the pectin/starch-ATP beads showed the best performance after UV exposure. Moreover, all formulations maintained more than 109 CFU g-1 after six months of storage, which meets values required for microbial inoculants.


Asunto(s)
Bacillus subtilis , Pectinas , Almidón , Portadores de Fármacos , Adenosina Trifosfato
3.
Biotechnol Prog ; 38(3): e3242, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35134271

RESUMEN

The use of phosphate rocks as low-solubility phosphorus fertilizers has been promoted to reduce the environmental impacts of agriculture, but adequate nutrient uptake by plants depends on solubilization of the rock, driven by soil microorganisms. Here, investigation was made of the microbial solubilization of low-solubility phosphate rocks, together with simultaneous bioprotective action involving the biocontrol of microorganisms. The aim was to enhance function and value by delivering two effects using a single bio-based product, in accordance with the concept of a "bioreactor-in-a-granule" system. A composite structure was developed, based on a starch matrix, comprising a combination of Trichoderma asperelloides, as a biocontrol agent, and Aspergillus niger, as an acidulant. A significant increase of up to 150% in P solubilization was achieved, indicating the positive effect of the microorganism-composite interaction. In vitro assays showed that the ability of T. asperelloides to inhibit Fusarium oxysporum mycelial growth was maintained in the presence of A. niger. Moreover, the estimated cost of the composite granule (0.35 US$/kg of product on a dry basis) revealed competitive. The results indicated that the association of T. asperelloides and A. niger is an effective way to increase nutrient availability and to inhibit plant pathogens, opening up possibilities for the design of multifunctional bio-based fertilizer composites.


Asunto(s)
Fósforo , Microbiología del Suelo , Fertilización , Fertilizantes , Fosfatos
4.
Biotechnol Prog ; 37(4): e3134, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33591633

RESUMEN

The manner in which added non-catalytic proteins during enzymatic hydrolysis of lignocellulosic substrates enhances hydrolysis mechanisms is not completely understood. Prior research has indicated that a reduction in the non-specific adsorption of enzymes on lignin, and deactivation of enzymes exposed to air-liquid interface provide rationale. This work investigated root causes including effects of the air-liquid interface on non-catalytic proteins, and effects of lignin on endoglucanase. Three different experimental designs and three variables (air-liquid interfacial area, the types of lignin (acid or enzymatic lignin), and the presence of non-enzymatic protein (bovine serum albumin [BSA] or soy proteins ) were used. The results showed that acid isolated lignin adsorbed almost all endoglucanase activity initially present in supernatant, independent of air interface conditions (25 or 250 ml flasks) with the presence of BSA preventing this effect. Endoglucanase lost 30%-50% of its activity due to an air-liquid interface in the presence of lignin while addition of non-enzymatic protein helped to preserve this enzyme's activity. Langmuir and Freundlich models applied to experimental data indicated that the adsorption increases with increasing temperature for both endoglucanase and BSA. Adsorption of the enzyme and protein were endothermic with an increase in entropy. These results, combined, show that hydrophobicity plays a strong role in the adsorption of both endoglucanase and BSA on lignin.


Asunto(s)
Celulasa , Lignina , Adsorción , Celulasa/metabolismo , Hidrólisis , Lignina/metabolismo , Albúmina Sérica Bovina
5.
Appl Biochem Biotechnol ; 192(1): 325-337, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32382943

RESUMEN

Many industrial enzymes can be highly glycosylated, including the ß-glucosidase enzymes. Although glycosylation plays an important role in many biological processes, such chains can cause problems in the multipoint immobilization techniques of the enzymes, since the glycosylated chains can cover the reactive groups of the protein (e.g., Lys) and do not allow those groups to react with reactive groups of the support (e.g., aldehyde and epoxy groups). Nevertheless, the activated glycosylated chains can be used as excellent crosslinking agents. The glycosylated chains when oxidized with periodate can generate aldehyde groups capable of reacting with the amino groups of the protein itself. Such intramolecular crosslinks may have significant stabilizing effects. In this study, we investigated if the intramolecular crosslinking occurs in the oxidized ß-glucosidase and its effect on the stability of the enzyme. For this, the oxidation of glycosidic chains of ß-glucosidase was carried out, allowing to demonstrate the formation of aldehyde groups and subsequent interaction with the amine groups and to verify the stability of the different forms of free enzyme (glycosylated and oxidized). Furthermore, we verified the influence of the glycosidic chains on the immobilization of ß-glucosidase from Aspergillus niger and on the consequent stabilization. The results suggest that intramolecular crosslinking occurred and consequently the oxidized enzyme showed a much greater stabilization than the native enzyme (glycosylated). When the multipoint immobilization was performed in amino-epoxy-agarose supports, the stabilization of the oxidized enzyme increases by a 6-fold factor. The overall stabilization strategy was capable to promote an enzyme stabilization of 120-fold regarding to the soluble unmodified enzyme.


Asunto(s)
Lisina/química , Oxígeno/química , beta-Glucosidasa/química , Aspergillus niger/enzimología , Biomasa , Celobiosa/química , DEAE-Celulosa/química , Estabilidad de Enzimas , Enzimas Inmovilizadas/química , Fermentación , Glucólisis , Glicósidos , Glicosilación , Concentración de Iones de Hidrógeno , Hidrólisis , Sefarosa/química , Temperatura , Factores de Tiempo
6.
Appl Microbiol Biotechnol ; 100(21): 9133-9144, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27245677

RESUMEN

Filamentous fungi are attractive hosts for heterologous protein expression due to their capacity to secrete large amounts of enzymes into the extracellular medium. Xyloglucanases, which specifically hydrolyze xyloglucan, have been recently applied in lignocellulosic biomass degradation and conversion in many other industrial processes. In this context, this work aimed to clone, express, and determine the functional properties of a recombinant xyloglucanase (AtXEG12) from Aspergillus terreus, and also its solid-state (SSF) and submerged (SmF) fermentation in bioreactors. The purified AtXEG12 showed optimum pH and temperature of 5.5 and 65 °C, respectively, demonstrating to be 90 % stable after 24 h of incubation at 50 °C. AtXEG12 activity increased in the presence of 2-mercaptoethanol (65 %) and Zn+2 (45 %), while Cu+2 and Ag+ ions drastically decreased its activity. A substrate assay showed, for the first time for this enzyme's family, xylanase activity. The enzyme exhibited high specificity for tamarind xyloglucan (K M 1.2 mg mL-1) and V max of 17.4 µmol min-1 mg-1 of protein. The capillary zone electrophoresis analysis revealed that AtXEG12 is an endo-xyloglucanase. The heterologous xyloglucanase secretion was greater than the production by wild-type A. terreus cultivated in SmF. On the other hand, AtXEG12 activity reached by SSF was sevenfold higher than values achieved by SmF, showing that the expression of recombinant enzymes can be significantly improved by cultivation under SSF.


Asunto(s)
Aspergillus/enzimología , Glicósido Hidrolasas/metabolismo , Lignina/metabolismo , Proteínas Recombinantes/metabolismo , Reactores Biológicos/microbiología , Clonación Molecular , Activadores de Enzimas/análisis , Inhibidores Enzimáticos/análisis , Estabilidad de Enzimas , Fermentación , Expresión Génica , Glicósido Hidrolasas/química , Glicósido Hidrolasas/genética , Glicósido Hidrolasas/aislamiento & purificación , Concentración de Iones de Hidrógeno , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/aislamiento & purificación , Especificidad por Sustrato , Tamarindus/química , Temperatura
7.
J Ind Microbiol Biotechnol ; 43(5): 617-26, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26883662

RESUMEN

The use of glycerol obtained as an intermediate of the biodiesel manufacturing process as carbon source for microbial growth is a potential alternative strategy for the production of enzymes and other high-value bioproducts. This work evaluates the production of cellulase enzymes using glycerol for high cell density growth of Trichoderma harzianum followed by induction with a cellulosic material. Firstly, the influence of the carbon source used in the pre-culture step was investigated in terms of total protein secretion and fungal morphology. Enzymatic productivity was then determined for cultivation strategies using different types and concentrations of carbon source, as well as different feeding procedures (batch and fed-batch). The best strategy for cellulase production was then further studied on a larger scale using a stirred tank bioreactor. The proposed strategy for cellulase production, using glycerol to achieve high cell density growth followed by induction with pretreated sugarcane bagasse, achieved enzymatic activities up to 2.27 ± 0.37 FPU/mL, 106.40 ± 8.87 IU/mL, and 9.04 ± 0.39 IU/mL of cellulase, xylanase, and ß-glucosidase, respectively. These values were 2 times higher when compared to the control experiments using glucose instead of glycerol. This novel strategy proved to be a promising approach for improving cellulolytic enzymes production, and could potentially contribute to adding value to biomass within the biofuels sector.


Asunto(s)
Reactores Biológicos , Celulasa/biosíntesis , Celulosa/metabolismo , Glicerol/metabolismo , Trichoderma/crecimiento & desarrollo , Trichoderma/metabolismo , Biocombustibles , Biomasa , Celulosa/farmacología , Glucosa/metabolismo , Glucosa/farmacología , Glicerol/farmacología , Saccharum/química , Trichoderma/citología , Trichoderma/enzimología , beta-Glucosidasa/metabolismo
8.
Ci. Rural ; 45(9): 1606-1612, Sept. 2015. graf
Artículo en Portugués | VETINDEX | ID: vti-27128

RESUMEN

A conversão da biomassa vegetal proveniente de resíduos agroindustriais e florestais em biocombustíveis e bioprodutos, dentro do conceito de biorrefinarias, é de grande interesse, principalmente para o Brasil, onde a agroenergia possui um enorme potencial de desenvolvimento. Entretanto, para garantir a viabilidade do processo de conversão, é fundamental reduzir o custo das enzimas utilizadas na etapa de hidrólise. Para isso, deve-se dispor da peça chave deste processo, que é o microrganismo. Nesse contexto, o objetivo deste trabalho foi avaliar fungos isolados da região Amazônica em relação ao potencial de produção das enzimas celulases e xilanases. De um total de 40 isolados cultivados por fermentação em estado sólido (FES), durante 10 dias, os fungos que se destacaram quanto à produção de endoglucanase (351,79Ug-1 em 120h) e -glicosidase (62,31Ug-1em 72h) foi o P47C3 (A. niger), e na produção de xilanase (1076,94Ug-1 em 72h) e FPase (2,46Ug-1 em 120h) foram o P6B2 (A. oryzae) e o P40B3, respectivamente. Os resultados obtidos demonstram o enorme potencial de aplicação das enzimas produzidas pelos fungos isolados da Amazônia, contribuindo, assim, para gerar os avanços tecnológicos necessários para o aumento da eficiência do uso da biomassa vegetal como fonte de energia renovável.(AU)


The conversion of biomass from forestry and agroindustrial residues into biofuels and bioproducts, within the biorefinery concept, is of great interest, especially to Brazil, where bioenergy has a huge potential for development. However, to ensure the viability of the conversion process it is essential to reduce the cost of the enzymes used in the hydrolysis step. For this, one must have the key element of this process, which is the microorganism. In this context, the objective of this study was to evaluate different fungi isolated from the Amazon region for their potential in terms of the production of cellulase and xylanase enzymes. Of a total of 40 strains cultivated under solid state fermentation (SSF) for 10 days, the strain that stood out for the production of endoglucanase (351.79Ug-1120h) and -glucosidase (62.31Ug-1 at 72h) was P47C3 (A. niger) whereas for xylanase (1076.94Ug-1 in 72 hours) and FPase (2.46Ug-1 in120 hours) were P6B2 (A. oryzae) and P40B3, respectively. These results demonstrate the great potential application of the enzymes produced by the Amazon isolated fungi, thus contributing to generate the necessary technological advances in order to increase the efficiency of the use of biomass as a renewable energy source.(AU)


Asunto(s)
Ecosistema Amazónico , Biomasa , Hongos/aislamiento & purificación , Celulasas , Enzimas
9.
Ciênc. rural ; Ciênc. rural (Online);45(9): 1606-1612, set. 2015. ilus
Artículo en Portugués | LILACS | ID: lil-756436

RESUMEN

A conversão da biomassa vegetal proveniente de resíduos agroindustriais e florestais em biocombustíveis e bioprodutos, dentro do conceito de biorrefinarias, é de grande interesse, principalmente para o Brasil, onde a agroenergia possui um enorme potencial de desenvolvimento. Entretanto, para garantir a viabilidade do processo de conversão, é fundamental reduzir o custo das enzimas utilizadas na etapa de hidrólise. Para isso, deve-se dispor da peça chave deste processo, que é o microrganismo. Nesse contexto, o objetivo deste trabalho foi avaliar fungos isolados da região Amazônica em relação ao potencial de produção das enzimas celulases e xilanases. De um total de 40 isolados cultivados por fermentação em estado sólido (FES), durante 10 dias, os fungos que se destacaram quanto à produção de endoglucanase (351,79Ug-1 em 120h) e β-glicosidase (62,31Ug-1em 72h) foi o P47C3 (A. niger), e na produção de xilanase (1076,94Ug-1 em 72h) e FPase (2,46Ug-1 em 120h) foram o P6B2 (A. oryzae) e o P40B3, respectivamente. Os resultados obtidos demonstram o enorme potencial de aplicação das enzimas produzidas pelos fungos isolados da Amazônia, contribuindo, assim, para gerar os avanços tecnológicos necessários para o aumento da eficiência do uso da biomassa vegetal como fonte de energia renovável

.

The conversion of biomass from forestry and agroindustrial residues into biofuels and bioproducts, within the biorefinery concept, is of great interest, especially to Brazil, where bioenergy has a huge potential for development. However, to ensure the viability of the conversion process it is essential to reduce the cost of the enzymes used in the hydrolysis step. For this, one must have the key element of this process, which is the microorganism. In this context, the objective of this study was to evaluate different fungi isolated from the Amazon region for their potential in terms of the production of cellulase and xylanase enzymes. Of a total of 40 strains cultivated under solid state fermentation (SSF) for 10 days, the strain that stood out for the production of endoglucanase (351.79Ug-1120h) and β-glucosidase (62.31Ug-1 at 72h) was P47C3 (A. niger) whereas for xylanase (1076.94Ug-1 in 72 hours) and FPase (2.46Ug-1 in120 hours) were P6B2 (A. oryzae) and P40B3, respectively. These results demonstrate the great potential application of the enzymes produced by the Amazon isolated fungi, thus contributing to generate the necessary technological advances in order to increase the efficiency of the use of biomass as a renewable energy source.

.

10.
Bioresour Technol ; 167: 206-13, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-24983691

RESUMEN

The ß-glucosidase (BG) enzyme plays a vital role in the hydrolysis of lignocellulosic biomass. Supplementation of the hydrolysis reaction medium with BG can reduce inhibitory effects, leading to greater conversion. In addition, the inclusion of immobilized BG can be a useful way of increasing enzyme stability and recyclability. BG was adsorbed on polyacrylic resin activated by carboxyl groups (BG-PC) and covalently attached to glyoxyl-agarose (BG-GA). BG-PC exhibited similar behavior to soluble BG in the hydrolysis of cellobiose, while BG-GA hydrolyzed the same substrate at a lower rate. However, the thermal stability of BG-GA was higher than that of free BG. Hydrolysis of pretreated sugarcane bagasse catalyzed by soluble cellulase supplemented with immobilized BG improved the conversion by up to 40% after 96 h of reaction. Both derivatives remained stable up to the third cycle and losses of activity were less than 50% after five cycles.


Asunto(s)
Biotecnología/métodos , Metabolismo de los Hidratos de Carbono , Celulasa/metabolismo , Celulosa/metabolismo , Enzimas Inmovilizadas/metabolismo , Saccharum/metabolismo , beta-Glucosidasa/metabolismo , Adsorción , Celobiosa , Estabilidad de Enzimas , Glioxilatos/química , Concentración de Iones de Hidrógeno , Hidrólisis , Sefarosa/química , Solubilidad , Temperatura , Trichoderma/enzimología
11.
Bioresour Technol ; 131: 500-7, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23391738

RESUMEN

Supplementation of cellulase cocktails with accessory enzymes can contribute to a higher hydrolytic capacity in releasing fermentable sugars from plant biomass. This study investigated which enzymes were complementary to the enzyme set of Trichoderma harzianum in the degradation of sugarcane bagasse. Specific activities of T. harzianum extract on different substrates were compared with the extracts of Penicillium echinulatum and Trichoderma reesei, and two commercial cellulase preparations. Complementary analysis of the secretome of T. harzianum was also used to identify which enzymes were produced during growth on pretreated sugarcane bagasse. These analyses enabled the selection of the enzymes pectinase and α-L-arabinofuranosidase (AF) to be further investigated as supplements to the T. harzianum extract. The effect of enzyme supplementation on the efficiency of sugarcane bagasse saccharification was evaluated using response surface methodology. The supplementation of T. harzianum enzymatic extract with pectinase and AF increased the efficiency of hydrolysis by up to 116%.


Asunto(s)
Carbohidratos/biosíntesis , Celulosa/metabolismo , Glicósido Hidrolasas/química , Poligalacturonasa/química , Saccharum/microbiología , Trichoderma/metabolismo , Carbohidratos/química , Celulosa/química , Activación Enzimática , Hidrólisis , Trichoderma/química , Trichoderma/clasificación
12.
Bioresour Technol ; 132: 401-5, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23265822

RESUMEN

This work investigates the glycosyl hydrolase (GH) profile of a new Trichoderma harzianum strain cultivated under controlled bioreactor submerged fermentation. The influence of different medium components (delignified steam-exploded sugarcane bagasse, sucrose, and soybean flour) on GH biosynthesis was assessed using experimental mixture design (EMD). Additionally, the effect of increased component concentrations in culture media selected from the EMD was studied. It was found that that a mixed culture medium could significantly maximize GH biosynthesis rate, especially for xylanase enzymes which achieved a 2-fold increment. Overall, it was demonstrated that T. harzianumP49P11 enzymes have a great potential to be used in the deconstruction of biomass.


Asunto(s)
Biocombustibles , Reactores Biológicos , Biotecnología/métodos , Glicósido Hidrolasas/biosíntesis , Trichoderma/enzimología , Biomasa , Brasil , Celulosa/metabolismo , Fermentación , Saccharum/metabolismo , Glycine max/metabolismo , Especificidad de la Especie , Sacarosa/metabolismo , Trichoderma/genética
13.
Enzyme Res ; 2012: 793708, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23227312

RESUMEN

The viability of converting biomass into biofuels and chemicals still requires further development towards the reduction of the enzyme production costs. Thus, there is a growing demand for the development of efficient procedures for selection of cellulase-producing microorganisms. This work correlates qualitative screening using agar plate assays with quantitative measurements of cellulase production during cultivation under solid-state fermentation (SSF). The initial screening step consisted of observation of the growth of 78 preselected strains of the genus Trichoderma on plates, using microcrystalline cellulose as carbon source. The 49 strains that were able to grow on this substrate were then subjected to a second screening step using the Congo red test. From this test it was possible to select 10 strains that presented the highest enzymatic indices (EI), with values ranging from 1.51 to 1.90. SSF cultivations using sugarcane bagasse and wheat bran as substrates were performed using selected strains. The CG 104NH strain presented the highest EGase activity (25.93 UI·g(-1)). The EI results obtained in the screening procedure using plates were compared with cellulase production under SSF. A correlation coefficient (R(2)) of 0.977 was obtained between the Congo red test and SSF, demonstrating that the two methodologies were in good agreement.

14.
Bioresour Technol ; 107: 517-21, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22221990

RESUMEN

The on-site production of cellulases is an important strategy for the development of sustainable second-generation ethanol production processes. This study concerns the use of a specific cellulolytic enzyme complex for hydrolysis of pretreated sugar cane bagasse. Glycosyl hydrolases (FPase, xylanase, and ß-glucosidase) were produced using a new strain of Trichoderma harzianum, isolated from the Amazon rainforest and cultivated under different conditions. The influence of the carbon source was first investigated using shake-flask cultures. Selected carbon sources were then further studied under different pH conditions using a stirred tank bioreactor. Enzymatic activities up to 121 FPU/g, 8000 IU/g, and 1730 IU/g of delignified steam-exploded bagasse+sucrose were achieved for cellulase, xylanase and ß-glucosidase, respectively. This enzymatic complex was used to hydrolyze pretreated sugar cane bagasse. A comparative evaluation, using an enzymatic extract from Trichoderma reesei RUTC30, indicated similar performance of the T. harzianum enzyme complex, being a potential candidate for on-site production of enzymes.


Asunto(s)
Celulasa/metabolismo , Trichoderma/metabolismo , América del Sur , Árboles , Trichoderma/aislamiento & purificación
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