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Nascimento AS, Muniz JRC, Aparício R, Golubev AM, Polikarpov I. Insights into the structure and function of fungal β-mannosidases from glycoside hydrolase family 2 based on multiple crystal structures of the Trichoderma harzianum enzyme. FEBS J 2014; 281:4165-78. [PMID: 24975648 DOI: 10.1111/febs.12894] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 06/15/2014] [Accepted: 06/24/2014] [Indexed: 11/28/2022]
Abstract
UNLABELLED Hemicellulose is an important part of the plant cell wall biomass, and is relevant to cellulosic ethanol technologies. β-Mannosidases are enzymes capable of cleaving nonreducing residues of β-d-mannose from β-d-mannosides and hemicellulose mannose-containing polysaccharides, such as mannans and galactomannans. β-Mannosidases are distributed between glycoside hydrolase (GH) families 1, 2, and 5, and only a handful of the enzymes have been structurally characterized to date. The only published X-ray structure of a GH family 2 mannosidase is that of the bacterial Bacteroides thetaiotaomicron enzyme. No structures of eukaryotic mannosidases of this family are currently available. To fill this gap, we set out to solve the structure of Trichoderma harzianum GH family 2 β-mannosidase and to refine it to 1.9-Å resolution. Structural comparisons of the T. harzianum GH2 β-mannosidase highlight similarities in its structural architecture with other members of GH family 2, reveal the molecular mechanism of β-mannoside binding and recognition, and shed light on its putative galactomannan-binding site. DATABASE Coordinates and observed structure factor amplitudes have been deposited with the Protein Data Bank (4CVU and 4UOJ). The T. harzianum β-mannosidase 2A nucleotide sequence has GenBank accession number BankIt1712036 GeneMark.hmm KJ624918.
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Abstract
A modified twin-screw extruder incorporated with a filtration device was used as a liquid/solid separator for xylose removal from steam exploded corncobs. A face centered central composite design was used to study the combined effects of various enzymatic hydrolysis process variables (enzyme loading, surfactant addition, and hydrolysis time) with two differently extruded corncobs (7% xylose removal, 80% xylose removal) on glucose conversion. The results showed that the extrusion process led to an increase in cellulose crystallinity, while structural changes could also be observed via SEM. A quadratic polynomial model was developed for predicting the glucose conversion and the fitted model provided an adequate approximation of the true response as verified by the analysis of variance (ANOVA).
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Optimisation of Cellulase Production by Penicillium funiculosum in a Stirred Tank Bioreactor Using Multivariate Response Surface Analysis. Enzyme Res 2014; 2014:703291. [PMID: 25057412 PMCID: PMC4099281 DOI: 10.1155/2014/703291] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Revised: 06/10/2014] [Accepted: 06/11/2014] [Indexed: 11/18/2022] Open
Abstract
Increasing interest in the production of second-generation ethanol necessitates the low-cost production of enzymes from the cellulolytic complex (endoglucanases, exoglucanases, and β-glucosidases), which act synergistically in cellulose breakdown. The present work aimed to optimise a bioprocess to produce these biocatalysts from the fungus Penicillium funiculosum ATCC11797. A statistical full factorial design (FFD) was employed to determine the optimal conditions for cellulase production. The optimal composition of culture media using Avicel (10 g·L−1) as carbon source was determined to include urea (1.2 g·L−1), yeast extract (1.0 g·L−1), KH2PO4 (6.0 g·L−1), and MgSO4·7H2O (1.2 g·L−1). The growth process was performed in batches in a bioreactor. Using a different FFD strategy, the optimised bioreactor operational conditions of an agitation speed of 220 rpm and aeration rate of 0.6 vvm allowed the obtainment of an enzyme pool with activities of 508 U·L−1 for FPase, 9,204 U·L−1 for endoglucanase, and 2,395 U·L−1 for β-glucosidase. The sequential optimisation strategy was effective and afforded increased cellulase production in the order from 3.6 to 9.5 times higher than production using nonoptimised conditions.
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Horta MAC, Vicentini R, Delabona PDS, Laborda P, Crucello A, Freitas S, Kuroshu RM, Polikarpov I, Pradella JGDC, Souza AP. Transcriptome profile of Trichoderma harzianum IOC-3844 induced by sugarcane bagasse. PLoS One 2014; 9:e88689. [PMID: 24558413 PMCID: PMC3928278 DOI: 10.1371/journal.pone.0088689] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2013] [Accepted: 01/09/2014] [Indexed: 12/03/2022] Open
Abstract
Profiling the transcriptome that underlies biomass degradation by the fungus Trichoderma harzianum allows the identification of gene sequences with potential application in enzymatic hydrolysis processing. In the present study, the transcriptome of T. harzianum IOC-3844 was analyzed using RNA-seq technology. The sequencing generated 14.7 Gbp for downstream analyses. De novo assembly resulted in 32,396 contigs, which were submitted for identification and classified according to their identities. This analysis allowed us to define a principal set of T. harzianum genes that are involved in the degradation of cellulose and hemicellulose and the accessory genes that are involved in the depolymerization of biomass. An additional analysis of expression levels identified a set of carbohydrate-active enzymes that are upregulated under different conditions. The present study provides valuable information for future studies on biomass degradation and contributes to a better understanding of the role of the genes that are involved in this process.
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Affiliation(s)
| | - Renato Vicentini
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Priscila da Silva Delabona
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Prianda Laborda
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Aline Crucello
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil
| | - Sindélia Freitas
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Reginaldo Massanobu Kuroshu
- Physics Institute of São Carlos, University of São Paulo (USP), São Carlos, SP, Brazil
- Institute of Science and Technology, Federal University of São Paulo (UNIFESP), São José dos Campos, SP, Brazil
| | - Igor Polikarpov
- Physics Institute of São Carlos, University of São Paulo (USP), São Carlos, SP, Brazil
| | - José Geraldo da Cruz Pradella
- Brazilian Bioethanol Science and Technology Laboratory (CTBE), Brazilian Center of Research in Energy and Materials (CNPEM), Campinas, SP, Brazil
| | - Anete Pereira Souza
- Center for Molecular Biology and Genetic Engineering (CBMEG), University of Campinas (UNICAMP), Campinas, SP, Brazil
- Department of Plant Biology, Biology Institute, University of Campinas (UNICAMP), Campinas, SP, Brazil
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55
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Benoliel B, Torres FAG, de Moraes LMP. A novel promising Trichoderma harzianum strain for the production of a cellulolytic complex using sugarcane bagasse in natura. SPRINGERPLUS 2013; 2:656. [PMID: 24349958 PMCID: PMC3862859 DOI: 10.1186/2193-1801-2-656] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/22/2013] [Accepted: 11/27/2013] [Indexed: 12/02/2022]
Abstract
Brazil is a major producer of agro-industrial residues, such as sugarcane bagasse, which could be used as raw material for microbial production of cellulases as an important strategy for the development of sustainable processes of second generation ethanol production. For this purpose, this work aimed at screening for glycosyl hydrolase activities of fungal strains isolated from the Brazilian Cerrado. Among 13 isolates, a Trichoderma harzianum strain (L04) was identified as a promising candidate for cellulase production when cultured on in natura sugarcane bagasse. Strain L04 revealed a well-balanced cellulolytic complex, presenting fast kinetic production of endoglucanases, exoglucanases and β-glucosidases, achieving 4,022, U.L-1 (72 h), 1,228 U.L-1 (120 h) and 1,968 U.L-1 (48 h) as the highest activities, respectively. About 60% glucose yields were obtained from sugarcane bagasse after 18 hours hydrolysis. This new strain represents a potential candidate for on-site enzyme production using sugarcane bagasse as carbon source.
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Affiliation(s)
- Bruno Benoliel
- Centro de Biotecnologia Molecular, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF, Brazil
| | - Fernando Araripe Gonçalves Torres
- Centro de Biotecnologia Molecular, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF, Brazil
| | - Lidia Maria Pepe de Moraes
- Centro de Biotecnologia Molecular, Departamento de Biologia Celular, Instituto de Ciências Biológicas, Universidade de Brasília, Brasília, DF, Brazil ; Laboratório de Biologia Molecular, Departamento de Biologia Celular, Universidade de Brasília, Brasília, DF 70910-900 Brazil
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56
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Barriuso J, Prieto A, Martínez MJ. Fungal genomes mining to discover novel sterol esterases and lipases as catalysts. BMC Genomics 2013; 14:712. [PMID: 24138290 PMCID: PMC3827930 DOI: 10.1186/1471-2164-14-712] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 08/28/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Sterol esterases and lipases are enzymes able to efficiently catalyze synthesis and hydrolysis reactions of both sterol esters and triglycerides and due to their versatility could be widely used in different industrial applications. Lipases with this ability have been reported in the yeast Candida rugosa that secretes several extracellular enzymes with a high level of sequence identity, although different substrate specificity. This versatility has also been found in the sterol esterases from the ascomycetes Ophiostoma piceae and Melanocarpus albomyces. RESULTS In this work we present an in silico search of new sterol esterase and lipase sequences from the genomes of environmental fungi. The strategy followed included identification and search of conserved domains from these versatile enzymes, phylogenetic studies, sequence analysis and 3D modeling of the selected candidates. CONCLUSIONS Six potential putative enzymes were selected and their kinetic properties and substrate selectivity are discussed on the basis of their similarity with previously characterized sterol esterases/lipases with known structures.
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Affiliation(s)
| | | | - Maria Jesus Martínez
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain.
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57
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Esperança MN, Cunha FM, Cerri MO, Zangirolami TC, Farinas CS, Badino AC. Gas hold-up and oxygen mass transfer in three pneumatic bioreactors operating with sugarcane bagasse suspensions. Bioprocess Biosyst Eng 2013; 37:805-12. [DOI: 10.1007/s00449-013-1049-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 09/03/2013] [Indexed: 11/29/2022]
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58
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Vats S, Negi S. Use of artificial neural network (ANN) for the development of bioprocess using Pinus roxburghii fallen foliages for the release of polyphenols and reducing sugars. BIORESOURCE TECHNOLOGY 2013; 140:392-398. [PMID: 23711945 DOI: 10.1016/j.biortech.2013.04.106] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2013] [Revised: 04/25/2013] [Accepted: 04/26/2013] [Indexed: 06/02/2023]
Abstract
In present study, different parameters, i.e., percentage of NaOH, loading volume, microwave power (watt) and volume of water during pretreatment were optimized by ANN for release of polyphenols and sugars from pine fallen foliage. ANN used was feed forward back propagation type with 72 input, 72 output and 10 hidden layers coupled with Lvenberg-Marquardt (LM) training algorithms. The predicted optimal values by generated neural network for alkali pretreatment were 6 ml (0.5% NaOH)/g of substrate, soaking time of 10 min followed by 1 min of 100 W microwave. Pretreated sample on enzymatic hydrolysis at 50°C for 20 h with cocktail of cellulase, xylanase and laccase produced by locally isolated consortia released 668.9 mg/g of total sugar and 265.06 mg/g of total polyphenols. Optimization by ANN showed good yield, therefore, indicating its suitability for bioprocess modeling and control for release of reducing sugars and polyphenols from pine foliage.
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Affiliation(s)
- Siddharth Vats
- Department of Biotechnology, Motilal Nehru National Institute of Technology, Allahabad 211 004, India
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59
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Ibrahim MF, Razak MNA, Phang LY, Hassan MA, Abd-Aziz S. Crude cellulase from oil palm empty fruit bunch by Trichoderma asperellum UPM1 and Aspergillus fumigatus UPM2 for fermentable sugars production. Appl Biochem Biotechnol 2013; 170:1320-35. [PMID: 23666614 DOI: 10.1007/s12010-013-0275-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Accepted: 04/29/2013] [Indexed: 11/25/2022]
Abstract
Cellulase is an enzyme that converts the polymer structure of polysaccharides into fermentable sugars. The high market demand for this enzyme together with the variety of applications in the industry has brought the research on cellulase into focus. In this study, crude cellulase was produced from oil palm empty fruit bunch (OPEFB) pretreated with 2% NaOH with autoclave, which was composed of 59.7% cellulose, 21.6% hemicellulose, and 12.3% lignin using Trichoderma asperellum UPM1 and Aspergillus fumigatus UPM2. Approximately 0.8 U/ml of FPase, 24.7 U/ml of CMCase and 5.0 U/ml of β-glucosidase were produced by T. asperellum UPM1 at a temperature of 35 °C and at an initial pH of 7.0. A 1.7 U/ml of FPase, 24.2 U/ml of CMCase, and 1.1 U/ml of β-glucosidase were produced by A. fumigatus UPM2 at a temperature of 45 °C and at initial pH of 6.0. The crude cellulase was best produced at 1% of substrate concentration for both T. asperellum UPM1 and A. fumigatus UPM2. The hydrolysis percentage of pretreated OPEFB using 5% of crude cellulase concentration from T. asperellum UPM1 and A. fumigatus UPM2 were 3.33% and 19.11%, with the reducing sugars concentration of 1.47 and 8.63 g/l, respectively.
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Affiliation(s)
- M F Ibrahim
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
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60
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Lima MA, Lavorente GB, da Silva HKP, Bragatto J, Rezende CA, Bernardinelli OD, deAzevedo ER, Gomez LD, McQueen-Mason SJ, Labate CA, Polikarpov I. Effects of pretreatment on morphology, chemical composition and enzymatic digestibility of eucalyptus bark: a potentially valuable source of fermentable sugars for biofuel production - part 1. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:75. [PMID: 23657132 PMCID: PMC3667114 DOI: 10.1186/1754-6834-6-75] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 04/26/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND In recent years, the growing demand for biofuels has encouraged the search for different sources of underutilized lignocellulosic feedstocks that are available in sufficient abundance to be used for sustainable biofuel production. Much attention has been focused on biomass from grass. However, large amounts of timber residues such as eucalyptus bark are available and represent a potential source for conversion to bioethanol. In the present paper, we investigate the effects of a delignification process with increasing sodium hydroxide concentrations, preceded or not by diluted acid, on the bark of two eucalyptus clones: Eucalyptus grandis (EG) and the hybrid, E. grandis x urophylla (HGU). The enzymatic digestibility and total cellulose conversion were measured, along with the effect on the composition of the solid and the liquor fractions. Barks were also assessed using Fourier-transform infrared spectroscopy (FTIR), solid-state nuclear magnetic resonance (NMR), X-Ray diffraction, and scanning electron microscopy (SEM). RESULTS Compositional analysis revealed an increase in the cellulose content, reaching around 81% and 76% of glucose for HGU and EG, respectively, using a two-step treatment with HCl 1%, followed by 4% NaOH. Lignin removal was 84% (HGU) and 79% (EG), while the hemicellulose removal was 95% and 97% for HGU and EG, respectively. However, when we applied a one-step treatment, with 4% NaOH, higher hydrolysis efficiencies were found after 48 h for both clones, reaching almost 100% for HGU and 80% for EG, in spite of the lower lignin and hemicellulose removal. Total cellulose conversion increased from 5% and 7% to around 65% for HGU and 59% for EG. NMR and FTIR provided important insight into the lignin and hemicellulose removal and SEM studies shed light on the cell-wall unstructuring after pretreatment and lignin migration and precipitation on the fibers surface, which explain the different hydrolysis rates found for the clones. CONCLUSION Our results show that the single step alkaline pretreatment improves the enzymatic digestibility of Eucalyptus bark. Furthermore, the chemical and physical methods combined in this study provide a better comprehension of the pretreatment effects on cell-wall and the factors that influence enzymatic digestibility of this forest residue.
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Affiliation(s)
- Marisa A Lima
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP, Brazil
| | - Gabriela B Lavorente
- Laboratório Max Feffer de Genética de Plantas, Departamento de Genética - ESALQ, Universidade de São Paulo, Caixa Postal 83, 13418-900, Piracicaba, SP, Brazil
| | - Hana KP da Silva
- Laboratório Max Feffer de Genética de Plantas, Departamento de Genética - ESALQ, Universidade de São Paulo, Caixa Postal 83, 13418-900, Piracicaba, SP, Brazil
| | - Juliano Bragatto
- Laboratório Max Feffer de Genética de Plantas, Departamento de Genética - ESALQ, Universidade de São Paulo, Caixa Postal 83, 13418-900, Piracicaba, SP, Brazil
| | - Camila A Rezende
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP, Brazil
| | - Oigres D Bernardinelli
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP, Brazil
| | - Eduardo R deAzevedo
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP, Brazil
| | - Leonardo D Gomez
- CNAP, Department of Biology, University of York, Heslington, York YO10 5YW, UK
| | | | - Carlos A Labate
- Laboratório Max Feffer de Genética de Plantas, Departamento de Genética - ESALQ, Universidade de São Paulo, Caixa Postal 83, 13418-900, Piracicaba, SP, Brazil
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, 13560-970, São Carlos, SP, Brazil
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Hargreaves PI, Barcelos CA, da Costa ACA, Pereira N. Production of ethanol 3G from Kappaphycus alvarezii: evaluation of different process strategies. BIORESOURCE TECHNOLOGY 2013; 134:257-263. [PMID: 23500583 DOI: 10.1016/j.biortech.2013.02.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Revised: 01/31/2013] [Accepted: 02/02/2013] [Indexed: 05/28/2023]
Abstract
This study evaluated the potential of Kappaphycus alvarezii as feedstock for ethanol production, i.e. ethanol 3G. First, aquatic biomass was subjected to a diluted acid pretreatment. This acid pretreatment generated two streams--a galactose-containing liquid fraction and a cellulose-containing solid fraction, which were investigated to determine their fermentability with the following strategies: a single-stream process (simultaneous saccharification and co-fermentation (SSCF) of both fractions altogether), which achieved 64.3 g L(-1) of ethanol, and a two-stream process (fractions were fermented separately), which resulted in 38 g L(-1) of ethanol from the liquid fraction and 53.0 g L(-1) from the simultaneous saccharification and fermentation (SSF) of the solid fraction. Based on the average fermentable carbohydrate concentration, it was possible to obtain 105 L of ethanol per ton of dry seaweed. These preliminaries results indicate that the use of the macro-algae K. alvarezii has a good potential feedstock for bioethanol production.
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Affiliation(s)
- Paulo Iiboshi Hargreaves
- Laboratórios de Desenvolvimento de Bioprocessos, Departamento de Engenharia Bioquímica, Escola de Química, Universidade Federal do Rio de Janeiro, Av., Horácio Macedo 2030, Bloco E, Rio de Janeiro 21949-900, Brazil
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da Silva FB, Romão BB, Cardoso VL, Filho UC, Ribeiro EJ. Production of ethanol from enzymatically hydrolyzed soybean molasses. Biochem Eng J 2012. [DOI: 10.1016/j.bej.2012.08.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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63
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Maeda RN, Barcelos CA, Santa Anna LMM, Pereira N. Cellulase production by Penicillium funiculosum and its application in the hydrolysis of sugar cane bagasse for second generation ethanol production by fed batch operation. J Biotechnol 2012; 163:38-44. [PMID: 23123260 DOI: 10.1016/j.jbiotec.2012.10.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 10/22/2012] [Accepted: 10/24/2012] [Indexed: 10/27/2022]
Abstract
This study aimed to produce a cellulase blend and to evaluate its application in a simultaneous saccharification and fermentation (SSF) process for second generation ethanol production from sugar cane bagasse. The sugar cane bagasse was subjected to pretreatments (diluted acid and alkaline), as for disorganizing the ligocellulosic complex, and making the cellulose component more amenable to enzymatic hydrolysis. The residual solid fraction was named sugar cane bagasse partially delignified cellulignin (PDC), and was used for enzyme production and ethanol fermentation. The enzyme production was performed in a bioreactor with two inoculum concentrations (5 and 10% v/v). The fermentation inoculated with higher inoculum size reduced the time for maximum enzyme production (from 72 to 48). The enzyme extract was concentrated using tangential ultrafiltration in hollow fiber membranes, and the produced cellulase blend was evaluated for its stability at 37 °C, operation temperature of the simultaneous SSF process, and at 50 °C, optimum temperature of cellulase blend activity. The cellulolytic preparation was stable for at least 300 h at both 37 °C and 50 °C. The ethanol production was carried out by PDC fed-batch SSF process, using the onsite cellulase blend. The feeding strategy circumvented the classic problems of diffusion limitations by diminishing the presence of a high solid:liquid ratio at any time, resulting in high ethanol concentration at the end of the process (100 g/L), which corresponded to a fermentation efficiency of 78% of the maximum obtainable theoretically. The experimental results led to the ratio of 380 L of ethanol per ton of sugar cane bagasse PDC.
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Affiliation(s)
- Roberto Nobuyuki Maeda
- Federal University of Rio de Janeiro, Center of Technology, School of Chemistry, Laboratories of Bioprocess Development, ZIP Code: 21949-900, Rio de Janeiro, Brazil
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64
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Cellulase production and oil palm empty fruit bunch saccharification by a new isolate of Trichoderma koningii D-64. Process Biochem 2012. [DOI: 10.1016/j.procbio.2012.07.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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65
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Cunha FM, Esperança MN, Zangirolami TC, Badino AC, Farinas CS. Sequential solid-state and submerged cultivation of Aspergillus niger on sugarcane bagasse for the production of cellulase. BIORESOURCE TECHNOLOGY 2012; 112:270-274. [PMID: 22409979 DOI: 10.1016/j.biortech.2012.02.082] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 02/07/2012] [Accepted: 02/16/2012] [Indexed: 05/31/2023]
Abstract
Sequential solid-state and submerged cultivation with sugarcane bagasse as substrate for cellulase production by Aspergillus niger A12 was assessed by measuring endoglucanase activity. An unconventional pre-culture with an initial fungal growth phase under solid-state cultivation was followed by a transition to submerged fermentation by adding the liquid culture medium to the mycelium grown on solid substrate. For comparison, control experiments were conducted using conventional submerged cultivation. The cultures were carried out in shake flasks and in a 5-L bubble column bioreactor. An endoglucanase productivity of 57 ± 13 IU/L/h was achieved in bubble column cultivations prepared using the new method, representing an approximately 3-fold improvement compared to conventional submerged fermentation. Therefore, the methodology proposed here of a sequential fermentation process offers a promising alternative for cellulase production.
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Affiliation(s)
- F M Cunha
- Department of Chemical Engineering, Federal University of São Carlos, C.P. 676, 13565-905 São Carlos, SP, Brazil
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Singh A, Bishnoi NR. Enzymatic hydrolysis optimization of microwave alkali pretreated wheat straw and ethanol production by yeast. BIORESOURCE TECHNOLOGY 2012; 108:94-101. [PMID: 22261656 DOI: 10.1016/j.biortech.2011.12.084] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/19/2011] [Revised: 12/15/2011] [Accepted: 12/16/2011] [Indexed: 05/31/2023]
Abstract
Microwave alkali pretreated wheat straw was used for in-house enzyme production by Aspergillusflavus and Trichodermareesei. Produced enzymes were concentrated, pooled and assessed for the hydrolysis of pretreated wheat straw. Factors affecting hydrolysis were screened out by Placket-Burman design (PBD) and most significant factors were further optimized by Box-Behnken design (BBD). Under optimum conditions, 82% efficiency in hydrolysis yield was observed. After the optimization by response surface methodology (RSM), a model was proposed to predict the optimum value confirmed by the experimental results. The concentrated enzymatic hydrolyzate was fermented for ethanol production by Saccharomyces cerevisiae, Pichia stipitis and co-culture of both. The yield of ethanol was found to be 0.48 g(p)/g(s), 0.43 g(p)/g(s) and 0.40 g(p)/g(s) by S. cerevisiae, P. stipitis and by co-culture, respectively, using concentrated enzymatic hydrolyzate. During anaerobic fermentation 42.31 μmol/mL, 36.69 μmol/mL, 43.35 μmol/mL CO(2) was released by S. cerevisiae, P. stipitis and by co-culture, respectively.
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Affiliation(s)
- Anita Singh
- Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar 125001, Haryana, India.
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Optimization of enzymatic hydrolysis of pretreated rice straw and ethanol production. Appl Microbiol Biotechnol 2012; 93:1785-93. [DOI: 10.1007/s00253-012-3870-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Revised: 12/21/2011] [Accepted: 12/23/2011] [Indexed: 10/14/2022]
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Rezende CA, de Lima MA, Maziero P, deAzevedo ER, Garcia W, Polikarpov I. Chemical and morphological characterization of sugarcane bagasse submitted to a delignification process for enhanced enzymatic digestibility. BIOTECHNOLOGY FOR BIOFUELS 2011; 4:54. [PMID: 22122978 PMCID: PMC3377919 DOI: 10.1186/1754-6834-4-54] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 11/28/2011] [Indexed: 05/03/2023]
Abstract
BACKGROUND In recent years, biorefining of lignocellulosic biomass to produce multi-products such as ethanol and other biomaterials has become a dynamic research area. Pretreatment technologies that fractionate sugarcane bagasse are essential for the successful use of this feedstock in ethanol production. In this paper, we investigate modifications in the morphology and chemical composition of sugarcane bagasse submitted to a two-step treatment, using diluted acid followed by a delignification process with increasing sodium hydroxide concentrations. Detailed chemical and morphological characterization of the samples after each pretreatment condition, studied by high performance liquid chromatography, solid-state nuclear magnetic resonance, diffuse reflectance Fourier transformed infrared spectroscopy and scanning electron microscopy, is reported, together with sample crystallinity and enzymatic digestibility. RESULTS Chemical composition analysis performed on samples obtained after different pretreatment conditions showed that up to 96% and 85% of hemicellulose and lignin fractions, respectively, were removed by this two-step method when sodium hydroxide concentrations of 1% (m/v) or higher were used. The efficient lignin removal resulted in an enhanced hydrolysis yield reaching values around 100%. Considering the cellulose loss due to the pretreatment (maximum of 30%, depending on the process), the total cellulose conversion increases significantly from 22.0% (value for the untreated bagasse) to 72.4%. The delignification process, with consequent increase in the cellulose to lignin ratio, is also clearly observed by nuclear magnetic resonance and diffuse reflectance Fourier transformed infrared spectroscopy experiments. We also demonstrated that the morphological changes contributing to this remarkable improvement occur as a consequence of lignin removal from the sample. Bagasse unstructuring is favored by the loss of cohesion between neighboring cell walls, as well as by changes in the inner cell wall structure, such as damaging, hole formation and loss of mechanical resistance, facilitating liquid and enzyme access to crystalline cellulose. CONCLUSIONS The results presented herewith show the efficiency of the proposed method for improving the enzymatic digestibility of sugarcane bagasse and provide understanding of the pretreatment action mechanism. Combining the different techniques applied in this work warranted thorough information about the undergoing morphological and chemical changes and was an efficient approach to understand the morphological effects resulting from sample delignification and its influence on the enhanced hydrolysis results.
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Affiliation(s)
- Camila Alves Rezende
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, CEP 13560-970, São Carlos, SP, Brazil
| | - Marisa Aparecida de Lima
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, CEP 13560-970, São Carlos, SP, Brazil
| | - Priscila Maziero
- Escola de Engenharia de Lorena, Universidade de São Paulo, CEP 12602-810, Lorena, SP, Brazil
| | - Eduardo Ribeiro deAzevedo
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, CEP 13560-970, São Carlos, SP, Brazil
| | - Wanius Garcia
- Universidade Federal do ABC, CEP 009210-170, Santo André, SP, Brazil
| | - Igor Polikarpov
- Instituto de Física de São Carlos, Universidade de São Paulo, Caixa Postal 369, CEP 13560-970, São Carlos, SP, Brazil
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Chen HY, Xue DS, Feng XY, Yao SJ. Screening and production of ligninolytic enzyme by a marine-derived fungal Pestalotiopsis sp. J63. Appl Biochem Biotechnol 2011; 165:1754-69. [PMID: 21947763 DOI: 10.1007/s12010-011-9392-y] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 09/15/2011] [Indexed: 11/28/2022]
Abstract
Marine-derived fungi are prone to produce structurally unique secondary metabolites, a considerable number of which display the promising biological properties and/or industrial applications. Among those, ligninolytic enzymes have attracted great interest in recent years. In this work, about 20 strains were isolated from sea mud samples collected in the East China Sea and then screened for their capacity to produce lignin-degrading enzymes. The results showed that a strain, named J63, had a great potential to secrete a considerable amount of laccase. Using molecular method, it was identified as an endophytic fungus, Pestalotiopsis sp. which was rarely reported as ligninolytic enzyme producer in the literature. The production of laccase by Pestalotiopsis sp. J63 was investigated under submerged fermentation (SF) and solid state fermentation (SSF) with various lignocellulosic by-products as substrates. The SSF of rice straw powder accumulated the highest level of laccase activity (10,700 IU/g substrate), whereas the SF of untreated sugarcane bagasse provided the maximum amount of laccase activity (2,000 IU/ml). The value was far higher than those reported by other reports. In addition, it produced 0.11 U/ml cellulase when alkaline-pretreated sugarcane bagasse was used as growth substrate under SF. Meanwhile, the growth of fungi and laccase production under different salinity conditions were also studied. It appeared to be a moderately halo-tolerant organism.
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Affiliation(s)
- Hui-Ying Chen
- Department of Chemical and Biological Engineering, Zhejiang University, Hangzhou 310027, China
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