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Portilla Llerena JP, Kiyota E, dos Santos FRC, Garcia JC, de Lima RF, Mayer JLS, dos Santos Brito M, Mazzafera P, Creste S, Nobile PM. ShF5H1 overexpression increases syringyl lignin and improves saccharification in sugarcane leaves. GM CROPS & FOOD 2024; 15:67-84. [PMID: 38507337 PMCID: PMC10956634 DOI: 10.1080/21645698.2024.2325181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2023] [Accepted: 02/26/2024] [Indexed: 03/22/2024]
Abstract
The agricultural sugarcane residues, bagasse and straws, can be used for second-generation ethanol (2GE) production by the cellulose conversion into glucose (saccharification). However, the lignin content negatively impacts the saccharification process. This polymer is mainly composed of guaiacyl (G), hydroxyphenyl (H), and syringyl (S) units, the latter formed in the ferulate 5-hydroxylase (F5H) branch of the lignin biosynthesis pathway. We have generated transgenic lines overexpressing ShF5H1 under the control of the C4H (cinnamate 4-hydroxylase) rice promoter, which led to a significant increase of up to 160% in the S/G ratio and 63% in the saccharification efficiency in leaves. Nevertheless, the content of lignin was unchanged in this organ. In culms, neither the S/G ratio nor sucrose accumulation was altered, suggesting that ShF5H1 overexpression would not affect first-generation ethanol production. Interestingly, the bagasse showed a significantly higher fiber content. Our results indicate that the tissue-specific manipulation of the biosynthetic branch leading to S unit formation is industrially advantageous and has established a foundation for further studies aiming at refining lignin modifications. Thus, the ShF5H1 overexpression in sugarcane emerges as an efficient strategy to improve 2GE production from straw.
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Affiliation(s)
- Juan Pablo Portilla Llerena
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
- Academic Department of Biology, Professional and Academic School of Biology, Universidad Nacional de San Agustín de Arequipa, Arequipa, Perú
| | - Eduardo Kiyota
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | | | - Julio C. Garcia
- Centro de Cana, Instituto Agronômico (IAC), Ribeirão Preto, Brazil
| | | | | | - Michael dos Santos Brito
- Centro de Cana, Instituto Agronômico (IAC), Ribeirão Preto, Brazil
- Institute of Science and Technology, Federal University of São Paulo, São José dos Campos, Brazil
| | - Paulo Mazzafera
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Silvana Creste
- Centro de Cana, Instituto Agronômico (IAC), Ribeirão Preto, Brazil
- Departamento de Genética, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil
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Olatunji KO, Madyira DM. Effect of acidic pretreatment on the microstructural arrangement and anaerobic digestion of Arachis hypogea shells; and process parameters optimization using response surface methodology. Heliyon 2023; 9:e15145. [PMID: 37095976 PMCID: PMC10121849 DOI: 10.1016/j.heliyon.2023.e15145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/28/2023] [Accepted: 03/28/2023] [Indexed: 04/26/2023] Open
Abstract
Enzymatic hydrolysis of lignocellulose feedstocks has been observed as the rate-limiting stage during anaerobic digestion. This necessitated the need for pretreatment before anaerobic digestion for an effective and efficient process. Therefore, this study investigated the impact of acidic pretreatment on Arachis hypogea shells, and different conditions of H2SO4 concentration, exposure time, and autoclave temperature were considered. The substrates were digested for 35 days at a mesophilic temperature to assess the impact of pretreatment on the microstructural organization of the substrate. For the purpose of examining the interactive correlations between the input parameters, response surface methodology (RSM) was used. The result reveals that acidic pretreatment has the strength to disrupt the recalcitrance features of Arachis hypogea shells and make them accessible for microorganisms' activities during anaerobic digestion. In this context, H2SO4 with 0.5% v. v-1 for 15 min at an autoclave temperature of 90 °C increases the cumulative biogas and methane released by 13 and 178%, respectively. The model's coefficient of determination (R2) demonstrated that RSM could model the process. Therefore, acidic pretreatment poses a novel means of total energy recovery from lignocellulose feedstock and can be investigated at the industrial scale.
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Isolation and Screening of Microorganisms for the Effective Pretreatment of Lignocellulosic Agricultural Wastes. BIOMED RESEARCH INTERNATIONAL 2021; 2021:5514745. [PMID: 34604384 PMCID: PMC8481070 DOI: 10.1155/2021/5514745] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/18/2021] [Revised: 08/21/2021] [Accepted: 09/02/2021] [Indexed: 11/17/2022]
Abstract
Lignocellulosic waste is the most abundant biorenewable biomass on earth, and its hydrolysis releases highly valued reducing sugars. However, the presence of lignin in the biopolymeric structure makes it highly resistant to solubilization thereby hindering the hydrolysis of cellulose and hemicellulose. Microorganisms are known for their potential complex enzymes that play a dominant role in lignocellulose conversion. Therefore, the current study was designed to isolate and screen potential microorganisms for their selective delignification ability for the pretreatment of lignocellulosic biomass. An extensive isolation and screening procedure yielded 36 desired isolates (22 bacteria, 7 basidiomycete fungi, and 7 filamentous fungi). Submerged cultivation of these desired microorganisms revealed 4 bacteria and 10 fungi with potent lignocellulolytic enzyme activities. The potent isolates were identified as Pleurotus, Trichoderma, Talaromyces, Bacillus, and Chryseobacterium spp. confirmed by morphological and molecular identification. The efficiency of these strains was determined through enzyme activities, and the degraded substrates were analyzed through scanning electron microscopy (SEM) and X-ray diffraction (XRD). Among all isolated microbes, Pleurotus spp. were found to have high laccase activity. The cellulose-decomposing and selective delignification strains were subjected to solid-state fermentation (SSF). SSF of field waste corn stalks as a single-carbon source provides Pleurotus spp. better condition for the secretion of ligninolytic enzymes. These isolated ligninolytic enzymes producing microorganisms may be used for the effective pretreatment of lignocellulosic agricultural wastes for the production of high value-added natural products by fermentation.
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Abdeshahian P, Ascencio JJ, Philippini RR, Antunes FAF, Dos Santos JC, da Silva SS. Utilization of sugarcane straw for production of β-glucan biopolymer by Lasiodiplodia theobromae CCT 3966 in batch fermentation process. BIORESOURCE TECHNOLOGY 2020; 314:123716. [PMID: 32650262 DOI: 10.1016/j.biortech.2020.123716] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 06/15/2020] [Accepted: 06/18/2020] [Indexed: 06/11/2023]
Abstract
β-Glucans as emerging biopolymer are widely produced by microorganisms in fermentation processes using commercial sugars which make process non-economic. Lignocellulosic substances are inexpensive carbon sources, which could be exploited for sustainable production of β-glucans. In this study, a lignocellulosic material, namely sugarcane straw (SCS) was utilized for the production of extracellular β-glucan by Lasiodiplodia theobromae CCT3966. SCS was subjected to acid and subsequent alkaline pretreatment, followed by enzymatic saccharification using cellulase enzyme. Quantity of 48.65 g/L glucose was released after enzymatic hydrolysis. β-Glucan production was performed by cultivation of fungal strain in SCS hydrolysate at 28 °C and initial culture pH 7. Highest β-glucan yield and productivity of 0.047 gg-1 and 0.014 gL-1h-1, respectively was obtained at 72 h fermentation time. Kinetic study of β-glucan production revealed experimental biosynthesis of β-glucan from SCS hydrolysate followed the trend generated by Logistic and Luedeking-Piret models. Chemical structure of biopolymer produced showed β-glucan constitution.
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Affiliation(s)
- Peyman Abdeshahian
- Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Brazil.
| | - Jesús Jiménez Ascencio
- Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Brazil
| | - Rafael R Philippini
- Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Brazil
| | | | - Júlio César Dos Santos
- Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Brazil
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Fan M, Li J, Bi G, Ye G, Zhang H, Xie J. Enhanced co-generation of cellulosic ethanol and methane with the starch/sugar-rich waste mixtures and Tween 80 in fed-batch mode. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:227. [PMID: 31572494 PMCID: PMC6757364 DOI: 10.1186/s13068-019-1562-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 09/07/2019] [Indexed: 06/10/2023]
Abstract
BACKGROUND The mixed-feedstock fermentation is a promising approach to enhancing the co-generation of cellulosic ethanol and methane from sugarcane bagasse (SCB) and molasses. However, the unmatched supply of the SCB and molasses remains a main obstacle built upon binary feedstock. Here, we propose a cellulose-starch-sugar ternary waste combinatory approach to overcome this bottleneck by integrating the starch-rich waste of Dioscorea composita Hemls. extracted residue (DER) in mixed fermentation. RESULTS The substrates of the pretreated SCB, DER and molasses with varying ratios were conducted at a relatively low solids loading of 12%, and the optimal mixture ratio of 1:0.5:0.5 for the pretreated SCB/DER/molasses was determined by evaluating the ethanol concentration and yield. Nevertheless, it was found that the ethanol yield decreased from 79.19 ± 0.20 to 62.31 ± 0.61% when the solids loading increased from 12 to 44% in batch modes, regardless of the fact that the co-fermentation of three-component feedstock was performed under the optimal condition defined above. Hence, different fermentation processes such as fed-batch and fed-batch + Tween 80 were implemented to further improve the ethanol concentration and yield at higher solids loading ranging between 36 and 44%. The highest ethanol concentration of 91.82 ± 0.86 g/L (69.33 ± 0.46% of theoretical yield) was obtained with fed-batch + Tween 80 mode during the simultaneous saccharification and fermentation at a high solids loading of 44%. Moreover, after the ethanol recovery, the remaining stillage was digested for biomethane production and finally yielded 320.72 ± 6.98 mL/g of volatile solids. CONCLUSIONS Integrated DER into the combination of SCB and molasses would be beneficial for ethanol production. The co-generation of bioethanol and biomethane by mixed cellulose-starch-sugar waste turns out to be a sustainable solution to improve the overall efficacy in biorefinery.
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Affiliation(s)
- Meishan Fan
- College of Forestry and Landscape Architecture, Guangdong Engineering Technology Research Center of Agricultural and Forestry Biomass, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642 China
| | - Jun Li
- School of International Relations, Sun Yat-sen University, Guangzhou, China
| | - Guican Bi
- College of Forestry and Landscape Architecture, Guangdong Engineering Technology Research Center of Agricultural and Forestry Biomass, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642 China
| | - Guangying Ye
- College of Forestry and Landscape Architecture, Guangdong Engineering Technology Research Center of Agricultural and Forestry Biomass, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642 China
| | - Hongdan Zhang
- College of Forestry and Landscape Architecture, Guangdong Engineering Technology Research Center of Agricultural and Forestry Biomass, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642 China
| | - Jun Xie
- College of Forestry and Landscape Architecture, Guangdong Engineering Technology Research Center of Agricultural and Forestry Biomass, Key Laboratory of Energy Plants Resource and Utilization, Ministry of Agriculture and Rural Affairs, South China Agricultural University, Guangzhou, 510642 China
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Hodgson-Kratky K, Papa G, Rodriguez A, Stavila V, Simmons B, Botha F, Furtado A, Henry R. Relationship between sugarcane culm and leaf biomass composition and saccharification efficiency. BIOTECHNOLOGY FOR BIOFUELS 2019; 12:247. [PMID: 31636706 PMCID: PMC6796448 DOI: 10.1186/s13068-019-1588-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 10/05/2019] [Indexed: 05/06/2023]
Abstract
BACKGROUND Lignocellulosic biomass is recognized as a promising renewable feedstock for the production of biofuels. However, current methods for converting biomass into fermentable sugars are considered too expensive and inefficient due to the recalcitrance of the secondary cell wall. Biomass composition can be modified to create varieties that are efficiently broken down to release cell wall sugars. This study focused on identifying the key biomass components influencing plant cell wall recalcitrance that can be targeted for selection in sugarcane, an important and abundant source of biomass. RESULTS Biomass composition and the amount of glucan converted into glucose after saccharification were measured in leaf and culm tissues from seven sugarcane genotypes varying in fiber composition after no pretreatment and dilute acid, hydrothermal and ionic liquid pretreatments. In extractives-free sugarcane leaf and culm tissue, glucan, xylan, acid-insoluble lignin (AIL) and acid-soluble lignin (ASL) ranged from 20 to 32%, 15% to 21%, 14% to 20% and 2% to 4%, respectively. The ratio of syringyl (S) to guaiacyl (G) content in the lignin ranged from 1.5 to 2.2 in the culm and from 0.65 to 1.1 in the leaf. Hydrothermal and dilute acid pretreatments predominantly reduced xylan content, while the ionic liquid (IL) pretreatment targeted AIL reduction. The amount of glucan converted into glucose after 26 h of pre-saccharification was highest after IL pretreatment (42% in culm and 63.5% in leaf) compared to the other pretreatments. Additionally, glucan conversion in leaf tissues was approximately 1.5-fold of that in culm tissues. Percent glucan conversion varied between genotypes but there was no genotype that was superior to all others across the pretreatment groups. Path analysis revealed that S/G ratio, AIL and xylan had the strongest negative associations with percent glucan conversion, while ASL and glucan content had strong positive influences. CONCLUSION To improve saccharification efficiency of lignocellulosic biomass, breeders should focus on reducing S/G ratio, xylan and AIL content and increasing ASL and glucan content. This will be key for the development of sugarcane varieties for bioenergy uses.
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Affiliation(s)
- K. Hodgson-Kratky
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072 Australia
| | - G. Papa
- Joint BioEnergy Institute, Emeryville, CA 94608 USA
- Advanced Biofuels and Bioproducts Process Development Unit, Emeryville, CA 94608 USA
| | - A. Rodriguez
- Joint BioEnergy Institute, Emeryville, CA 94608 USA
- Sandia National Laboratories, Livermore, CA 94550 USA
| | - V. Stavila
- Sandia National Laboratories, Livermore, CA 94550 USA
| | - B. Simmons
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072 Australia
- Joint BioEnergy Institute, Emeryville, CA 94608 USA
| | - F. Botha
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072 Australia
- Sugar Research Australia, Brisbane, QLD 4068 Australia
| | - A. Furtado
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072 Australia
| | - R. Henry
- Queensland Alliance for Agriculture and Food Innovation, University of Queensland, Brisbane, QLD 4072 Australia
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Kazeem MO, Shah UKM, Baharuddin AS, AbdulRahman NA. Prospecting Agro-waste Cocktail: Supplementation for Cellulase Production by a Newly Isolated Thermophilic B. licheniformis 2D55. Appl Biochem Biotechnol 2017; 182:1318-1340. [PMID: 28176140 PMCID: PMC5534209 DOI: 10.1007/s12010-017-2401-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 01/09/2017] [Indexed: 01/17/2023]
Abstract
Bacteria isolated from thermophilic environment that can produce cellulase as well as utilise agro-waste biomass have a high potential for developing thermostable cellulase required in the biofuel industry. The cost for cellulase represents a significant challenge in converting lignocellulose to fermentable sugars for biofuel production. Among three potential bacteria examined, Bacillus licheniformis 2D55 (accession no. KT799651) was found to produce the highest cellulolytic activity (CMCase 0.33 U/mL and FPase 0.09 U/mL) at 18–24 h fermentation when grown on microcrystalline cellulose (MCC) as a carbon source in shake flask at 50 °C. Cellulase production process was further conducted on the untreated and NaOH pretreated rice straw (RS), rice husk (RH), sugarcane bagasse (BAG) and empty fruit bunch (EFB). Untreated BAG produced the highest FPase (0.160 U/mL), while the highest CMCase (0.150 U/mL) was supported on the pretreated RH. The mixture of untreated BAG and pretreated RH as agro-waste cocktail has remarkably improved CMCase (3.7- and 1.4-fold) and FPase (2.5- and 11.5-fold) compared to the untreated BAG and pretreated RH, respectively. The mechanism of cellulase production explored through SEM analysis and the location of cellulase enzymes of the isolate was also presented. Agro-waste cocktail supplementation provides an alternative method for an efficient production of cellulase.
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Affiliation(s)
- Muinat Olanike Kazeem
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.,Department of Microbiology, Faculty of Life Sciences, University of Ilorin, Ilorin, Kwara State, 1515, Nigeria
| | - Umi Kalsom Md Shah
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia
| | - Azhari Samsu Baharuddin
- Department of Process and Food Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 UPM, Serdang, Selangor, Malaysia
| | - Nor' Aini AbdulRahman
- Department of Bioprocess Technology, Faculty of Biotechnology and Biomolecular Sciences, Universiti Putra Malaysia, 43400, Serdang, Selangor, Malaysia.
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Li QM, Shi Z, Xiong XY, Wen Q, Hu QL, Su XJ. Ethanol production from xylose by Fusarium oxysporum and the optimization of culture conditions. BIOCATAL BIOTRANSFOR 2016. [DOI: 10.1080/10242422.2016.1212848] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Qing-ming Li
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, PR China,
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, Hunan, PR China,
| | - Zhuo Shi
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, PR China,
| | - Xing-yao Xiong
- The Institute of Vegetables and Flowers, Chinese Academy of Agriculture Sciences, Beijing, PR China, and
| | - Qian Wen
- College of Food Science and Technology, Hunan Agricultural University, Changsha, Hunan, PR China,
| | - Qiu-long Hu
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, Hunan, PR China,
| | - Xiao-jun Su
- Hunan Provincial Key Laboratory of Crop Germplasm Innovation and Utilization, Hunan Agricultural University, Changsha, Hunan, PR China,
- Hunan Collaborative Innovation for Utilization of Botanical Functional Ingredients, Hunan Agricultural University, Changsha, Hunan, PR China
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Seidl PR, Freire E, Borschiver S. Non-fuel Applications of Sugars in Brazil. BIOMASS SUGARS FOR NON-FUEL APPLICATIONS 2015. [DOI: 10.1039/9781782622079-00228] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The use of biomass for the production of fuels and chemicals can mitigate several of the problems involving greenhouse gas emissions and the depletion of the world's non-renewable resources. High value, lower volume biobased chemicals may also increase the return on investments in biofuels-only operations thus contributing to overcome a significant barrier to realizing a biorefinery's economic goals. Recent evaluations of structures most easily obtained from a given conversion process have the advantage of tailoring broad-based processes to the building blocks available from certain biorefinery operations. Selected structures available from chemical and biological transformations of sugar cane and its residues are discussed in terms of their integration into biorefinery operations. Those structures currently under investigation by Brazilian groups that appear to be the most promising for production by the chemical industry are discussed.
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Affiliation(s)
- Peter R. Seidl
- Brazilian Green Chemistry School, School of Chemistry Federal University of Rio de Janeiro Brazil
| | - Estevão Freire
- Brazilian Green Chemistry School, School of Chemistry Federal University of Rio de Janeiro Brazil
| | - Suzana Borschiver
- Brazilian Green Chemistry School, School of Chemistry Federal University of Rio de Janeiro Brazil
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Pereira SC, Maehara L, Machado CMM, Farinas CS. 2G ethanol from the whole sugarcane lignocellulosic biomass. BIOTECHNOLOGY FOR BIOFUELS 2015; 8:44. [PMID: 25774217 PMCID: PMC4359543 DOI: 10.1186/s13068-015-0224-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 02/09/2015] [Indexed: 05/07/2023]
Abstract
BACKGROUND In the sugarcane industry, large amounts of lignocellulosic residues are generated, which includes bagasse, straw, and tops. The use of the whole sugarcane lignocellulosic biomass for the production of second-generation (2G) ethanol can be a potential alternative to contribute to the economic viability of this process. Here, we conducted a systematic comparative study of the use of the lignocellulosic residues from the whole sugarcane lignocellulosic biomass (bagasse, straw, and tops) from commercial sugarcane varieties for the production of 2G ethanol. In addition, the feasibility of using a mixture of these residues from a selected variety was also investigated. RESULTS The materials were pretreated with dilute acid and hydrolyzed with a commercial enzymatic preparation, after which the hydrolysates were fermented using an industrial strain of Saccharomyces cerevisiae. The susceptibility to enzymatic saccharification was higher for the tops, followed by straw and bagasse. Interestingly, the fermentability of the hydrolysates showed a different profile, with straw achieving the highest ethanol yields, followed by tops and bagasse. Using a mixture of the different sugarcane parts (bagasse-straw-tops, 1:1:1, in a dry-weight basis), it was possible to achieve a 55% higher enzymatic conversion and a 25% higher ethanol yield, compared to use of the bagasse alone. For the four commercial sugarcane varieties evaluated using the same experimental set of conditions, it was found that the variety of sugarcane was not a significant factor in the 2G ethanol production process. CONCLUSIONS Assessment of use of the whole lignocellulosic sugarcane biomass clearly showed that 2G ethanol production could be significantly improved by the combined use of bagasse, straw, and tops, when compared to the use of bagasse alone. The lower susceptibility to saccharification of sugarcane bagasse, as well as the lower fermentability of its hydrolysates, can be compensated by using it in combination with straw and tops (sugarcane trash). Furthermore, given that the variety was not a significant factor for the 2G ethanol production process within the four commercial sugarcane varieties evaluated here, agronomic features such as higher productivity and tolerance of soil and climate variations can be used as the criteria for variety selection.
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Affiliation(s)
| | - Larissa Maehara
- />Embrapa Instrumentation, Rua XV de Novembro 1452, 13560-970 São Carlos, SP Brazil
- />Graduate Program of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luiz, km 235, 13565-905 São Carlos, SP Brazil
| | | | - Cristiane Sanchez Farinas
- />Embrapa Instrumentation, Rua XV de Novembro 1452, 13560-970 São Carlos, SP Brazil
- />Graduate Program of Chemical Engineering, Federal University of São Carlos, Rodovia Washington Luiz, km 235, 13565-905 São Carlos, SP Brazil
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