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Varriale L, Geib D, Ulber R. Short-term adaptation as a tool to improve bioethanol production using grass press-juice as fermentation medium. Appl Microbiol Biotechnol 2024; 108:393. [PMID: 38916650 PMCID: PMC11199226 DOI: 10.1007/s00253-024-13224-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2024] [Revised: 06/03/2024] [Accepted: 06/04/2024] [Indexed: 06/26/2024]
Abstract
Grass raw materials collected from grasslands cover more than 30% of Europe's agricultural area. They are considered very attractive for the production of different biochemicals and biofuels due to their high availability and renewability. In this study, a perennial ryegrass (Lolium perenne) was exploited for second-generation bioethanol production. Grass press-cake and grass press-juice were separated using mechanical pretreatment, and the obtained juice was used as a fermentation medium. In this work, Saccharomyces cerevisiae was utilized for bioethanol production using the grass press-juice as the sole fermentation medium. The yeast was able to release about 11 g/L of ethanol in 72 h, with a total production yield of 0.38 ± 0.2 gEthanol/gsugars. It was assessed to improve the fermentation ability of Saccharomyces cerevisiae by using the short-term adaptation. For this purpose, the yeast was initially propagated in increasing the concentration of press-juice. Then, the yeast cells were re-cultivated in 100%(v/v) fresh juice to verify if it had improved the fermentation efficiency. The fructose conversion increased from 79 to 90%, and the ethanol titers reached 18 g/L resulting in a final yield of 0.50 ± 0.06 gEthanol/gsugars with a volumetric productivity of 0.44 ± 0.00 g/Lh. The overall results proved that short-term adaptation was successfully used to improve bioethanol production with S. cerevisiae using grass press-juice as fermentation medium. KEY POINTS: • Mechanical pretreatment of grass raw materials • Production of bioethanol using grass press-juice as fermentation medium • Short-term adaptation as a tool to improve the bioethanol production.
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Affiliation(s)
- Ludovica Varriale
- Department of Mechanical and Process Engineering, Division of Bioprocess Engineering, Rhein-Palatinate Technical University Kaiserslautern-Landau, Gottlieb-Daimler-Str. 49, 67663, Kaiserslautern, Germany
| | - Doris Geib
- Department of Mechanical and Process Engineering, Division of Bioprocess Engineering, Rhein-Palatinate Technical University Kaiserslautern-Landau, Gottlieb-Daimler-Str. 49, 67663, Kaiserslautern, Germany
| | - Roland Ulber
- Department of Mechanical and Process Engineering, Division of Bioprocess Engineering, Rhein-Palatinate Technical University Kaiserslautern-Landau, Gottlieb-Daimler-Str. 49, 67663, Kaiserslautern, Germany.
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Wang Y, Zhang Y, Cui Q, Feng Y, Xuan J. Composition of Lignocellulose Hydrolysate in Different Biorefinery Strategies: Nutrients and Inhibitors. Molecules 2024; 29:2275. [PMID: 38792135 PMCID: PMC11123716 DOI: 10.3390/molecules29102275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2024] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
The hydrolysis and biotransformation of lignocellulose, i.e., biorefinery, can provide human beings with biofuels, bio-based chemicals, and materials, and is an important technology to solve the fossil energy crisis and promote global sustainable development. Biorefinery involves steps such as pretreatment, saccharification, and fermentation, and researchers have developed a variety of biorefinery strategies to optimize the process and reduce process costs in recent years. Lignocellulosic hydrolysates are platforms that connect the saccharification process and downstream fermentation. The hydrolysate composition is closely related to biomass raw materials, the pretreatment process, and the choice of biorefining strategies, and provides not only nutrients but also possible inhibitors for downstream fermentation. In this review, we summarized the effects of each stage of lignocellulosic biorefinery on nutrients and possible inhibitors, analyzed the huge differences in nutrient retention and inhibitor generation among various biorefinery strategies, and emphasized that all steps in lignocellulose biorefinery need to be considered comprehensively to achieve maximum nutrient retention and optimal control of inhibitors at low cost, to provide a reference for the development of biomass energy and chemicals.
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Affiliation(s)
- Yilan Wang
- Department of Bioscience and Bioengineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing 100083, China
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
| | - Yuedong Zhang
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
- Shandong Energy Institute, 189 Songling Road, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, 189 Songling Road, Qingdao 266101, China
| | - Qiu Cui
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
- State Key Laboratory of Microbial Technology, Shandong University, Qingdao 266237, China
| | - Yingang Feng
- CAS Key Laboratory of Biofuels, Shandong Provincial Key Laboratory of Synthetic Biology, Shandong Engineering Laboratory of Single Cell Oil, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, 189 Songling Road, Qingdao 266101, China
- Shandong Energy Institute, 189 Songling Road, Qingdao 266101, China
- Qingdao New Energy Shandong Laboratory, 189 Songling Road, Qingdao 266101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jinsong Xuan
- Department of Bioscience and Bioengineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Beijing 100083, China
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Divyashri G, Tulsi NP, Murthy TPK, Shreyas S, Kavya R, Jaishree IK. Valorization of coffee bean processing waste for bioethanol production: comparison and evaluation of mass transfer effects in fermentations using free and encapsulated cells of Saccharomyces cerevisiae. Bioprocess Biosyst Eng 2024; 47:169-179. [PMID: 38195720 DOI: 10.1007/s00449-023-02961-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 12/09/2023] [Indexed: 01/11/2024]
Abstract
Coffee husk, an agricultural waste abundant in carbohydrates and nutrients, is typically discarded through landfills, mixed with animal fodder, or incinerated. However, in alignment with sustainable development principles, researchers worldwide are exploring innovative methods to harness the value of coffee husk, transforming it into profitable products. One such avenue is the biotechnological approach to bioethanol production from agricultural wastes, offering an eco-friendly alternative to mitigate the adverse effects of fossil fuels. This study delves into the feasibility of utilizing coffee husk as a substrate for bioethanol production, employing and comparing various hydrolysis methods. The enzymatic hydrolysis method outshone thermochemical and thermal approaches, yielding 1.84 and 3.07 times more reducing sugars in the hydrolysate, respectively. In examining bioethanol production, a comparison between free and encapsulated cells in enzyme hydrolysate revealed that free-cell fermentation faced challenges due to cell viability issues. Under specific fermentation conditions, bioethanol yield (0.59 and 0.83 g of bioethanol/g of reducing sugar) and productivity (0.1 and 0.12 g/L h) were achieved for free and encapsulated cells, respectively. However, it was noted that bioethanol production by encapsulated cells was more significantly influenced by internal mass transfer effects, as indicated by the Thiele modulus and effectiveness factor. In conclusion, our findings underscore the potential of coffee husk as a valuable substrate for bioethanol production, showcasing its viability in contributing to sustainable and eco-friendly practices.
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Affiliation(s)
- G Divyashri
- Department of Biotechnology, M S Ramaiah Institute of Technology, Bangalore, 560 054, India.
| | - N P Tulsi
- Department of Biotechnology, M S Ramaiah Institute of Technology, Bangalore, 560 054, India
| | - T P Krishna Murthy
- Department of Biotechnology, M S Ramaiah Institute of Technology, Bangalore, 560 054, India
| | - S Shreyas
- Department of Biotechnology, M S Ramaiah Institute of Technology, Bangalore, 560 054, India
| | - R Kavya
- Department of Biotechnology, M S Ramaiah Institute of Technology, Bangalore, 560 054, India
| | - I K Jaishree
- Department of Biotechnology, M S Ramaiah Institute of Technology, Bangalore, 560 054, India
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Statistical optimization of bioethanol production from giant reed hydrolysate by Candida tropicalis using Taguchi design. J Biotechnol 2022; 360:71-78. [PMID: 36272574 DOI: 10.1016/j.jbiotec.2022.10.007] [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: 06/12/2022] [Revised: 10/11/2022] [Accepted: 10/16/2022] [Indexed: 12/12/2022]
Abstract
The economic production of bioethanol as a sustainable liquid fuel is particularly needed and attractive. Giant reed as a low-cost and renewable biomass can be utilized as a sustainable feedstock for bioethanol development. The current research focuses on optimizing the fermentation parameters to increase ethanol concentration while lowering production costs. In this work, the giant reed was hydrolyzed thermochemically using HCl; cellulose and hemicellulose fractions were maximally converted at optimized hydrolysis conditions (5% HCl, 30 min, and 120 °C), resulting in a high sugar concentration (≈ 55 g/L), which were fermented by Candida tropicalis Y-26 for bioethanol production (≈ 15 g/L). Taguchi design was used to optimize the fermentation parameters (temperatures, pH, incubation period, and nitrogen sources). Under optimum fermentation conditions (25 °C; 24 h.; pH 5.5; and ammonium nitrate as a nitrogen source), the ethanol concentration at flask level accomplished ≈ 21 g/L, while its scale-up to bioreactor level contributed ≈ 25 g/L (equivalent to 250 kg ethanol/ton biomass) with ≈ 67% increase than the fermentation under unoptimized conditions. Overall, these findings proved that optimizing the fermentation parameters by Taguchi design and scaling up at a bioreactor could improve bioethanol production from giant reed biomass.
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de Mélo AHF, Nunes AL, Carvalho PH, da Silva MF, Teixeira GS, Goldbeck R. Evaluation of Saccharomyces cerevisiae modified via CRISPR/Cas9 as a cellulosic platform microorganism in simultaneously saccharification and fermentation processes. Bioprocess Biosyst Eng 2022:10.1007/s00449-022-02765-1. [PMID: 35932337 DOI: 10.1007/s00449-022-02765-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 07/26/2022] [Indexed: 11/26/2022]
Abstract
The nonrenewable character and deleterious effects of fossil fuels foster the need for cleaner and more inexhaustible energy sources, such as bioethanol. Especially from lignocellulosic biomasses. However, the economic viability of this product in the market depends on process optimization and cost reduction. This research applied a sequential experimental project to investigate the process of enzymatic saccharification and simultaneous fermentation to produce ethanol with sugarcane bagasse. The differential of the work was the application of the strain of Saccharomyces cerevisiae AGY001 which was improved by evolutionary engineering to become thermotolerant and by a heterologous expression based on genomic integration by CRISPR/Cas9 to produce endoglucanase and β-glucosidase (AsENDO-AsBGL). The maximum ethanol yield found was 89% of the maximum theoretical yield (released sugars), obtained at temperature concentrations, sugarcane bagasse and inoculum at 40 °C, 16.5%, and 4.0 g/L, respectively (12.5 FPU/g bagasse). The mathematical model obtained can predict approximately 83% of the data set with 95% confidence. Therefore, these findings demonstrated the potential of sugarcane bagasse and S. cerevisiae AGY001 strain (CRISPR/Cas9 modified) in bioethanol production without the need for impractical selection media on an industrial scale, in addition to providing useful insights for the development of SSF processes.
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Affiliation(s)
- Allan H F de Mélo
- Bioprocess and Metabolic Engineering Laboratory, Food Engineering and Technology Department, School of Food Engineering, University of Campinas, Campinas, Campinas, SP, Brazil
| | - Alexia L Nunes
- Bioprocess and Metabolic Engineering Laboratory, Food Engineering and Technology Department, School of Food Engineering, University of Campinas, Campinas, Campinas, SP, Brazil
| | - Priscila H Carvalho
- Bioprocess and Metabolic Engineering Laboratory, Food Engineering and Technology Department, School of Food Engineering, University of Campinas, Campinas, Campinas, SP, Brazil
| | - Marcos F da Silva
- Bioprocess and Metabolic Engineering Laboratory, Food Engineering and Technology Department, School of Food Engineering, University of Campinas, Campinas, Campinas, SP, Brazil
| | - Gleidson S Teixeira
- Bioprocess and Metabolic Engineering Laboratory, Food Engineering and Technology Department, School of Food Engineering, University of Campinas, Campinas, Campinas, SP, Brazil
| | - Rosana Goldbeck
- Bioprocess and Metabolic Engineering Laboratory, Food Engineering and Technology Department, School of Food Engineering, University of Campinas, Campinas, Campinas, SP, Brazil.
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7
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Energy plants as biofuel source and as accumulators of heavy metals. HEMIJSKA INDUSTRIJA 2022. [DOI: 10.2298/hemind220402017n] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Fossil fuel depletion and soil and water pollution gave impetus to the
development of a novel perspective of sustainable development. In addition
to the use of plant biomass for ethanol production, plants can be used to
reduce the concentration of heavy metals in soil and water. Due to tolerance
to high levels of metals, many plant species, crops, non-crops, medicinal,
and pharmaceutical energy plants are well-known metal hyperaccumulators.
This paper focuses on studies investigating the potential of Miscanthus sp.,
Beta vulgaris L., Saccharum sp., Ricinus communis L. Prosopis sp. and Arundo
donax L. in heavy metal removal and biofuel production. Phytoremediation
employing these plants showed great potential for bioaccumulation of Co, Cr,
Cu, Al, Pb, Ni, Fe, Cd, Zn, Hg, Se, etc. This review presents the potential
of lignocellulose plants to remove pollutants being a valuable substrate for
biofuel production. Also, pretreat-ments, dealing with toxic biomass, and
biofuel production are discussed.
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Hoang AT, Nizetic S, Ong HC, Chong CT, Atabani AE, Pham VV. Acid-based lignocellulosic biomass biorefinery for bioenergy production: Advantages, application constraints, and perspectives. JOURNAL OF ENVIRONMENTAL MANAGEMENT 2021; 296:113194. [PMID: 34243094 DOI: 10.1016/j.jenvman.2021.113194] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 06/14/2021] [Accepted: 06/29/2021] [Indexed: 06/13/2023]
Abstract
The production of chemicals and fuels from renewable biomass with the primary aim of reducing carbon footprints has recently become one of the central points of interest. The use of lignocellulosic biomass for energy production is believed to meet the main criteria of maximizing the available global energy source and minimizing pollutant emissions. However, before usage in bioenergy production, lignocellulosic biomass needs to undergo several processes, among which biomass pretreatment plays an important role in the yield, productivity, and quality of the products. Acid-based pretreatment, one of the existing methods applied for lignocellulosic biomass pretreatment, has several advantages, such as short operating time and high efficiency. A thorough analysis of the characteristics of acid-based biomass pretreatment is presented in this review. The environmental concerns and future challenges involved in using acid pretreatment methods are discussed in detail to achieve clean and sustainable bioenergy production. The application of acid to biomass pretreatment is considered an effective process for biorefineries that aim to optimize the production of desired products while minimizing the by-products.
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Affiliation(s)
- Anh Tuan Hoang
- Institute of Engineering, Ho Chi Minh City University of Technology (HUTECH), Ho Chi Minh City, Viet Nam.
| | - Sandro Nizetic
- University of Split, FESB, Rudjera Boskovica 32, 21000, Split, Croatia
| | - Hwai Chyuan Ong
- Centre for Green Technology, Faculty of Engineering and IT, University of Technology Sydney, NSW, 2007, Australia.
| | - Cheng Tung Chong
- China-UK Low Carbon College, Shanghai Jiao Tong University, Lingang, Shanghai, 201306, China
| | - A E Atabani
- Alternative Fuels Research Laboratroy (AFRL), Energy Division, Department of Mechanical Engineering, Faculty of Engineering, Erciyes University, 38039, Kayseri, Turkey
| | - Van Viet Pham
- Institute of Maritime, Ho Chi Minh City University of Transport, Ho Chi Minh City, Viet Nam.
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Optimization of Carotenoids Production from Camelina sativa Meal Hydrolysate by Rhodosporidium toruloides. FERMENTATION-BASEL 2021. [DOI: 10.3390/fermentation7040208] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Several compounds on the market derive from petrochemical synthesis, and carotenoids are no exception. Nonetheless, since their applications in the food, feed and cosmetic sectors, and because of sustainability issues, carotenoids of natural origin are desirable. Carotenoids can be extracted from several plants but also from carotenogenic microorganisms, among which are yeasts. Nonetheless, to meet sustainability criteria, the substrate used for yeast cultivation has to be formulated from residual biomasses. For these reasons, we deploy the yeast, Rhodosporidium toruloides, to obtain carotenoids from Camelina sativa meal, an underrated lignocellulosic biomass. Its enzymatic hydrolysis ensures the release of the sugars, as well as of the other nutrients necessary to sustain the process. We therefore separately optimized enzymatic and biomass loadings, and calculated the yields and productivities of the obtained carotenoids. The best conditions (9% w/v biomass, 0.56% w/wbiomass enzymes) were tested in different settings, in which the fermentation was performed separately or simultaneously with hydrolysis, resulting in a similar production of carotenoids. In order to collect quantitative data under controlled chemo-physical parameters, the process was implemented in stirred-tank bioreactors, obtaining 3.6 ± 0.69 mg/L of carotenoids; despite the volumetric and geometric change, the outcomes were consistent with results from the fermentation of shake flasks. Therefore, these data pave the way to evaluate a potential future industrialization of this bioprocess, considering the opportunity to optimize the use of different amounts of biomass and enzyme loading, as well as the robustness of the process in the bioreactor.
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Bertacchi S, Jayaprakash P, Morrissey JP, Branduardi P. Interdependence between lignocellulosic biomasses, enzymatic hydrolysis and yeast cell factories in biorefineries. Microb Biotechnol 2021; 15:985-995. [PMID: 34289233 PMCID: PMC8913906 DOI: 10.1111/1751-7915.13886] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 06/23/2021] [Accepted: 06/23/2021] [Indexed: 11/30/2022] Open
Abstract
Biorefineries have a pivotal role in the bioeconomy scenario for the transition from fossil‐based processes towards more sustainable ones relying on renewable resources. Lignocellulose is a prominent feedstock since its abundance and relatively low cost. Microorganisms are often protagonists of biorefineries, as they contribute both to the enzymatic degradation of lignocellulose complex polymers and to the fermentative conversion of the hydrolyzed biomasses into fine and bulk chemicals. Enzymes have therefore become crucial for the development of sustainable biorefineries, being able to provide nutrients to cells from lignocellulose. Enzymatic hydrolysis can be performed by a portfolio of natural enzymes that degrade lignocellulose, often combined into cocktails. As enzymes can be deployed in different operative settings, such as separate hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF), their characteristics need to be combined with microbial ones to maximize the process. We therefore reviewed how the optimization of lignocellulose enzymatic hydrolysis can ameliorate bioethanol production when Saccharomyces cerevisiae is used as cell factory. Expanding beyond biofuels, enzymatic cocktail optimization can also be pivotal to unlock the potential of non‐Saccharomyces yeasts, which, thanks to broader substrate utilization, inhibitor resistance and peculiar metabolism, can widen the array of feedstocks and products of biorefineries.
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Affiliation(s)
- Stefano Bertacchi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, Milano, 20126, Italy
| | - Pooja Jayaprakash
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, Milano, 20126, Italy.,School of Microbiology, Environmental Research Institute, APC Microbiome Institute, University College Cork, Cork, T12 K8AF, Ireland
| | - John P Morrissey
- School of Microbiology, Environmental Research Institute, APC Microbiome Institute, University College Cork, Cork, T12 K8AF, Ireland
| | - Paola Branduardi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, Milano, 20126, Italy
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Persson M, Galbe M, Wallberg O. A strategy for synergistic ethanol yield and improved production predictability through blending feedstocks. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:156. [PMID: 32944072 PMCID: PMC7487856 DOI: 10.1186/s13068-020-01791-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Accepted: 08/21/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND The integration of first- and second-generation bioethanol processes has the potential to accelerate the establishment of second-generation bioethanol on the market. Cofermenting pretreated wheat straw with a glucose-rich process stream, such as wheat grain hydrolysate, in a simultaneous saccharification and fermentation process could address the technical issues faced during the biological conversion of lignocellulose to ethanol. For example, doing so can increase the final ethanol concentration in the broth and mitigate the effects of inhibitors formed during the pretreatment. Previous research has indicated that blends of first- and second-generation substrates during simultaneous saccharification and fermentation have synergistic effects on the final ethanol yield, an important parameter in the process economy. In this study, enzymatic hydrolysis and simultaneous saccharification and fermentation were examined using blends of pretreated wheat straw and saccharified wheat grain at various ratios. The aim of this study was to determine the underlying mechanisms of the synergy of blending with regard to the yield and volumetric productivity of ethanol. RESULTS Replacing 25% of the pretreated wheat straw with wheat grain hydrolysate during simultaneous saccharification and fermentation was sufficient to decrease the residence time needed to deplete soluble glucose from 96 to 24 h and shift the rate-limiting step from ethanol production to the rate of enzymatic hydrolysis. Further, a synergistic effect on ethanol yield was observed with blended substrates, coinciding with lower glycerol production. Also, blending substrates had no effect on the yield of enzymatic hydrolysis. CONCLUSIONS The effects of substrate blending on the volumetric productivity of ethanol were attributed to changes in the relative rates of cell growth and cell death due to alterations in the concentrations of substrate and pretreatment-derived inhibitors. The synergistic effect of substrate blending on ethanol yield was attributed in part to the decreased production of cell mass and glycerol. Thus, it is preferable to perform simultaneous saccharification and fermentation with substrate blends rather than pure substrates with regard to yield, productivity, and the robustness of the process.
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Affiliation(s)
- Michael Persson
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Mats Galbe
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
| | - Ola Wallberg
- Department of Chemical Engineering, Lund University, P.O. Box 124, 221 00 Lund, Sweden
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12
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Extended fed-batch fermentation of a C5/C6 optimised yeast strain on wheat straw hydrolysate using an online refractive index sensor to measure the relative fermentation rate. Sci Rep 2020; 10:6705. [PMID: 32317712 PMCID: PMC7174321 DOI: 10.1038/s41598-020-63626-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Accepted: 02/18/2020] [Indexed: 02/06/2023] Open
Abstract
In the production of 2nd generation ethanol, using Saccharomyces cerevisiae, the highest productivity obtained using C5/C6 fermenting yeast is in the co-fermentation phase, in which xylose and glucose are fermented simultaneously. Extending this phase in a fed-batch process increases the yield, rate and additionally reduces needed yeast amount for pitching. Extending this phase, as long as possible, would further enhance yield and economy of the process. To realise the concept a fermentation monitoring technique was developed and applied. Based on online measured refractive index an optimal residual sugar concentration could be maintained in the primary fermentor during the feed phase, requiring little knowledge of the nature of the substrate. The system was able to run stably for at least five fermentor volumes giving an ethanol yield >90% throughout the run. This was achieved with addition of only urea to the wheat straw hydrolysate and with an initial yeast pitch of 0.2 g/L total of finished broth. It has the potential to improve the fermentation technology used in fuel ethanol plants, which could help to meet the growing demand for more sustainable fuels.
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Bertacchi S, Bettiga M, Porro D, Branduardi P. Camelina sativa meal hydrolysate as sustainable biomass for the production of carotenoids by Rhodosporidium toruloides. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:47. [PMID: 32190112 PMCID: PMC7066749 DOI: 10.1186/s13068-020-01682-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 02/18/2020] [Indexed: 06/10/2023]
Abstract
BACKGROUND As the circular economy advocates a near total waste reduction, the industry has shown an increased interest toward the exploitation of various residual biomasses. The origin and availability of biomass used as feedstock strongly affect the sustainability of biorefineries, where it is converted in energy and chemicals. Here, we explored the valorization of Camelina meal, the leftover residue from Camelina sativa oil extraction. In fact, in addition to Camelina meal use as animal feed, there is an increasing interest in further valorizing its macromolecular content or its nutritional value. RESULTS Camelina meal hydrolysates were used as nutrient and energy sources for the fermentation of the carotenoid-producing yeast Rhodosporidium toruloides in shake flasks. Total acid hydrolysis revealed that carbohydrates accounted for a maximum of 31 ± 1.0% of Camelina meal. However, because acid hydrolysis is not optimal for subsequent microbial fermentation, an enzymatic hydrolysis protocol was assessed, yielding a maximum sugar recovery of 53.3%. Separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF), and SSF preceded by presaccharification of Camelina meal hydrolysate produced 5 ± 0.7, 16 ± 1.9, and 13 ± 2.6 mg/L of carotenoids, respectively. Importantly, the presence of water-insoluble solids, which normally inhibit microbial growth, correlated with a higher titer of carotenoids, suggesting that the latter could act as scavengers. CONCLUSIONS This study paves the way for the exploitation of Camelina meal as feedstock in biorefinery processes. The process under development provides an example of how different final products can be obtained from this side stream, such as pure carotenoids and carotenoid-enriched Camelina meal, can potentially increase the initial value of the source material. The obtained data will help assess the feasibility of using Camelina meal to generate high value-added products.
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Affiliation(s)
- Stefano Bertacchi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Maurizio Bettiga
- Division of Industrial Biotechnology, Department of Biology and Biological Engineering, Chalmers University of Technology, Kemivägen 10, 412 96 Gothenburg, Sweden
- EviKrets Biobased Processes Consultants, Lunnavägen 87, 42834 Landvetter, Sweden
| | - Danilo Porro
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
| | - Paola Branduardi
- Department of Biotechnology and Biosciences, University of Milano-Bicocca, Piazza della Scienza 2, 20126 Milan, Italy
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14
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Toor M, Kumar SS, Malyan SK, Bishnoi NR, Mathimani T, Rajendran K, Pugazhendhi A. An overview on bioethanol production from lignocellulosic feedstocks. CHEMOSPHERE 2020; 242:125080. [PMID: 31675581 DOI: 10.1016/j.chemosphere.2019.125080] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 09/25/2019] [Accepted: 10/05/2019] [Indexed: 05/22/2023]
Abstract
Lignocellulosic ethanol has been proposed as a green alternative to fossil fuels for many decades. However, commercialization of lignocellulosic ethanol faces major hurdles including pretreatment, efficient sugar release and fermentation. Several processes were developed to overcome these challenges e.g. simultaneous saccharification and fermentation (SSF). This review highlights the various ethanol production processes with their advantages and shortcomings. Recent technologies such as singlepot biorefineries, combined bioprocessing, and bioenergy systems with carbon capture are promising. However, these technologies have a lower technology readiness level (TRL), implying that additional efforts are necessary before being evaluated for commercial availability. Solving energy needs is not only a technological solution and interlinkage of various factors needs to be assessed beyond technology development.
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Affiliation(s)
- Manju Toor
- Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar, 125 001, Haryana, India
| | - Smita S Kumar
- Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar, 125 001, Haryana, India
| | - Sandeep K Malyan
- Institute for Soil, Water, and Environmental Sciences, The Volcani Center, Agricultural Research Organization (ARO), Rishon LeZion - 7505101, Israel
| | - Narsi R Bishnoi
- Department of Environmental Science and Engineering, Guru Jambheshwar University of Science and Technology, Hisar, 125 001, Haryana, India
| | - Thangavel Mathimani
- Department of Energy and Environment, National Institute of Technology, Tiruchirappalli - 620 015, Tamil Nadu, India
| | - Karthik Rajendran
- Department of Environmental Science, SRM University-AP, Amaravati, Andhra Pradesh - 522502, India
| | - Arivalagan Pugazhendhi
- Innovative Green Product Synthesis and Renewable Environment Development Research Group, Faculty of Environment and Labour Safety, Ton Duc Thang University, Ho Chi Minh City, Viet Nam.
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Pratto B, Dos Santos-Rocha MSR, Longati AA, de Sousa Júnior R, Cruz AJG. Experimental optimization and techno-economic analysis of bioethanol production by simultaneous saccharification and fermentation process using sugarcane straw. BIORESOURCE TECHNOLOGY 2020; 297:122494. [PMID: 31813817 DOI: 10.1016/j.biortech.2019.122494] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 11/22/2019] [Accepted: 11/23/2019] [Indexed: 06/10/2023]
Abstract
The present work aims to determine a suitable yield-productivity balance in bioethanol production from hydrothermally pretreated sugarcane straw via pre-saccharification (PS) and simultaneous saccharification and fermentation (SSF). PS experiments were carried out evaluating effects of enzymatic dosage, biomass loading, and PS time. The performance of the whole process (PSSSF) was evaluated based on overall ethanol yield and productivity considering a simultaneous optimization (desirability function) of both variables. The multi-criteria optimization enabled to reach 5.7% w/w ethanol concentration yielding 290 L of ethanol per ton of pretreated sugarcane straw within 45 h of total processing time. Furthermore, a techno-economic analysis was performed under optimized conditions (14.5 FPU/gcellulose, 19.3% w/v biomass loading and 33 h PS time). This process was integrated into a first-generation plant. Although the economic evaluation exhibited a negative performance, a sensitivity analysis indicated that a decrease of 23.3% in operational expenditure would be enough to achieve feasibility.
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Affiliation(s)
- Bruna Pratto
- Chemical Engineering Graduate Program, Federal University of São Carlos, Rod. Washington Luís-Km 235, CEP: 13565-905 São Carlos, SP, Brazil.
| | | | - Andreza Aparecida Longati
- Department of Materials and Bioprocess Engineering, School of Chemical Engineering, University of Campinas, 13083-852 Campinas, SP, Brazil; Fundação Educacional de Ituverava, Rua Cel. Flauzino Barbosa Sandoval, 1259, CEP: 14500-000 Ituverava, SP, Brazil
| | - Ruy de Sousa Júnior
- Chemical Engineering Graduate Program, Federal University of São Carlos, Rod. Washington Luís-Km 235, CEP: 13565-905 São Carlos, SP, Brazil; Chemical Engineering Department, Federal University of São Carlos, Rod. Washington Luís-Km 235, CEP: 13565-905 São Carlos, SP, Brazil
| | - Antonio José Gonçalves Cruz
- Chemical Engineering Graduate Program, Federal University of São Carlos, Rod. Washington Luís-Km 235, CEP: 13565-905 São Carlos, SP, Brazil; Chemical Engineering Department, Federal University of São Carlos, Rod. Washington Luís-Km 235, CEP: 13565-905 São Carlos, SP, Brazil.
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Abo BO, Gao M, Wang Y, Wu C, Ma H, Wang Q. Lignocellulosic biomass for bioethanol: an overview on pretreatment, hydrolysis and fermentation processes. REVIEWS ON ENVIRONMENTAL HEALTH 2019; 34:57-68. [PMID: 30685745 DOI: 10.1515/reveh-2018-0054] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2018] [Accepted: 12/17/2018] [Indexed: 05/14/2023]
Abstract
Bioethanol is currently the only alternative to gasoline that can be used immediately without having to make any significant changes in the way fuel is distributed. In addition, the carbon dioxide (CO2) released during the combustion of bioethanol is the same as that used by the plant in the atmosphere for its growth, so it does not participate in the increase of the greenhouse effect. Bioethanol can be obtained by fermentation of plants containing sucrose (beet, sugar cane…) or starch (wheat, corn…). However, large-scale use of bioethanol implies the use of very large agricultural surfaces for maize or sugarcane production. Lignocellulosic biomass (LCB) such as agricultural residues for the production of bioethanol seems to be a solution to this problem due to its high availability and low cost even if its growth still faces technological difficulties. In this review, we present an overview of lignocellulosic biomass, the different methods of pre-treatment of LCB and the various fermentation processes that can be used to produce bioethanol from LCB.
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Affiliation(s)
- Bodjui Olivier Abo
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
| | - Ming Gao
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
- Beijing Key Laboratory on Disposal and Resource Recovery of Industry Typical Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Yonglin Wang
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
| | - Chuanfu Wu
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
- Beijing Key Laboratory on Disposal and Resource Recovery of Industry Typical Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Hongzhi Ma
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
- Beijing Key Laboratory on Disposal and Resource Recovery of Industry Typical Pollutants, University of Science and Technology Beijing, Beijing, China
| | - Qunhui Wang
- Department of Environmental Engineering, School of Energy and Environmental Engineering, University of Science and Technology Beijing, 30 Xueyuan Road, Haidian District, Beijing 100083, China
- Beijing Key Laboratory on Disposal and Resource Recovery of Industry Typical Pollutants, University of Science and Technology Beijing, Beijing, China
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Varriale S, Houbraken J, Granchi Z, Pepe O, Cerullo G, Ventorino V, Chin-A-Woeng T, Meijer M, Riley R, Grigoriev IV, Henrissat B, de Vries RP, Faraco V. Talaromyces borbonicus, sp. nov., a novel fungus from biodegraded Arundo donax with potential abilities in lignocellulose conversion. Mycologia 2018; 110:316-324. [PMID: 29843575 DOI: 10.1080/00275514.2018.1456835] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A novel fungal species able to synthesize enzymes with potential synergistic actions in lignocellulose conversion was isolated from the biomass of Arundo donax during biodegradation under natural conditions in the Gussone Park of the Royal Palace of Portici (Naples, Italy). In this work, this species was subjected to morphological and phylogenetic analyses. Sequencing of its genome was performed, resulting in 28 scaffolds that were assembled into 27.05 Mb containing 9744 predicted genes, among which 396 belong to carbohydrate-active enzyme (CAZyme)-encoding genes. Here we describe and illustrate this previously unknown species, which was named Talaromyces borbonicus, by a polyphasic approach combining phenotypic, physiological, and sequence data.
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Affiliation(s)
- Simona Varriale
- a Department of Chemical Sciences , University of Naples Federico II, Complesso Universitario Monte S. Angelo , via Cintia, 4 80126 Naples , Italy
| | - Jos Houbraken
- b Department of Applied and Industrial Mycology , Westerdijk Fungal Biodiversity Institute , Uppsalalaan 8, 3584 CT Utrecht , The Netherlands
| | - Zoraide Granchi
- c GenomeScan B.V., Plesmanlaan 1/D, 2333 BZ Leiden , The Netherlands
| | - Olimpia Pepe
- d Department of Agricultural Sciences , University of Naples Federico II , Via Università 100, 80055 Portici (NA) , Italy
| | - Gabriella Cerullo
- a Department of Chemical Sciences , University of Naples Federico II, Complesso Universitario Monte S. Angelo , via Cintia, 4 80126 Naples , Italy
| | - Valeria Ventorino
- d Department of Agricultural Sciences , University of Naples Federico II , Via Università 100, 80055 Portici (NA) , Italy
| | | | - Martin Meijer
- b Department of Applied and Industrial Mycology , Westerdijk Fungal Biodiversity Institute , Uppsalalaan 8, 3584 CT Utrecht , The Netherlands
| | - Robert Riley
- f US Department of Energy Joint Genome Institute , 2800 Mitchell Drive, Walnut Creek , California 94598
| | - Igor V Grigoriev
- f US Department of Energy Joint Genome Institute , 2800 Mitchell Drive, Walnut Creek , California 94598
| | - Bernard Henrissat
- g Architecture et Fonction des Macromolécules Biologiques (AFMB), UMR 7257 CNRS , Université Aix-Marseille , 163 Avenue de Luminy, 13288 , Marseille , France.,h INRA, USC 1408 AFMB, 13288 , Marseille , France.,i Department of Biological Sciences , King Abdulaziz University , Jeddah , Saudi Arabia
| | - Ronald P de Vries
- j Department of Fungal Physiology , Westerdijk Fungal Biodiversity Institute , Uppsalalaan 8, 3584 CT Utrecht , The Netherlands.,k Department of Fungal Molecular Physiology , Utrecht University , Uppsalalaan 8, 3584 CT Utrecht , The Netherlands
| | - Vincenza Faraco
- a Department of Chemical Sciences , University of Naples Federico II, Complesso Universitario Monte S. Angelo , via Cintia, 4 80126 Naples , Italy
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18
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Guo H, Chang Y, Lee DJ. Enzymatic saccharification of lignocellulosic biorefinery: Research focuses. BIORESOURCE TECHNOLOGY 2018; 252:198-215. [PMID: 29329774 DOI: 10.1016/j.biortech.2017.12.062] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 06/07/2023]
Abstract
To realize lignocellulosic biorefinery is of global interest, with enzymatic saccharification presenting an essential stage to convert polymeric sugars to mono-sugars for fermentation use. This mini-review summarizes qualitatively the research focuses discussed the review articles presented in the past 22 months and other relevant papers. The research focuses on pretreatment with improved efficiency, enhanced enzyme production with high yields and high extreme tolerance, feasible combined saccharification and fermentation processes, detailed mechanisms corresponding to the enzymatic saccharification in lignocellulosic biorefinery, and the costs are discussed.
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Affiliation(s)
- Hongliang Guo
- College of Food Engineering, Harbin University of Commerce, Harbin 150076, China
| | - Yingju Chang
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan
| | - Duu-Jong Lee
- Department of Chemical Engineering, National Taiwan University, Taipei 10617, Taiwan; Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 10607, Taiwan; State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China.
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Wu ZY, Yang J, Liu YH, Wang YZ, Zhang WX, Deng Y. Optimizing Semisimultaneous Saccharification and Fermentation for Ethanol Production from Chinese Distiller's Spent Grains. JOURNAL OF THE AMERICAN SOCIETY OF BREWING CHEMISTS 2018. [DOI: 10.1094/asbcj-2015-0407-01] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Zheng-Yun Wu
- Department of Food Engineering, College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, China
| | - Jian Yang
- Department of Food Engineering, College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, China
| | - Yue-Hong Liu
- Department of Food Engineering, College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, China
| | - Yin-Zhao Wang
- Department of Food Engineering, College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, China
| | - Wen-Xue Zhang
- Department of Food Engineering, College of Light Industry, Textile and Food Engineering, Sichuan University, Chengdu 610065, China
| | - Yu Deng
- Biogas Institute of Ministry of Agriculture, Chengdu 610041, China
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20
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Laluce C, Igbojionu LI, Dussán KJ. Fungal Enzymes Applied to Industrial Processes for Bioethanol Production. Fungal Biol 2018. [DOI: 10.1007/978-3-319-90379-8_4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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21
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Mika LT, Cséfalvay E, Németh Á. Catalytic Conversion of Carbohydrates to Initial Platform Chemicals: Chemistry and Sustainability. Chem Rev 2017; 118:505-613. [DOI: 10.1021/acs.chemrev.7b00395] [Citation(s) in RCA: 662] [Impact Index Per Article: 94.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- László T. Mika
- Department
of Chemical and Environmental Process Engineering, Budapest University of Technology and Economics, Műegyetem rkp. 3., Budapest 1111, Hungary
| | - Edit Cséfalvay
- Department
of Energy Engineering, Budapest University of Technology and Economics, Budapest 1111, Hungary
| | - Áron Németh
- Department
of Applied Biotechnology and Food Science, Budapest University of Technology and Economics, Budapest 1111, Hungary
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22
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Mohd Azhar SH, Abdulla R, Jambo SA, Marbawi H, Gansau JA, Mohd Faik AA, Rodrigues KF. Yeasts in sustainable bioethanol production: A review. Biochem Biophys Rep 2017; 10:52-61. [PMID: 29114570 PMCID: PMC5637245 DOI: 10.1016/j.bbrep.2017.03.003] [Citation(s) in RCA: 173] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 02/10/2017] [Accepted: 03/04/2017] [Indexed: 12/23/2022] Open
Abstract
Bioethanol has been identified as the mostly used biofuel worldwide since it significantly contributes to the reduction of crude oil consumption and environmental pollution. It can be produced from various types of feedstocks such as sucrose, starch, lignocellulosic and algal biomass through fermentation process by microorganisms. Compared to other types of microoganisms, yeasts especially Saccharomyces cerevisiae is the common microbes employed in ethanol production due to its high ethanol productivity, high ethanol tolerance and ability of fermenting wide range of sugars. However, there are some challenges in yeast fermentation which inhibit ethanol production such as high temperature, high ethanol concentration and the ability to ferment pentose sugars. Various types of yeast strains have been used in fermentation for ethanol production including hybrid, recombinant and wild-type yeasts. Yeasts can directly ferment simple sugars into ethanol while other type of feedstocks must be converted to fermentable sugars before it can be fermented to ethanol. The common processes involves in ethanol production are pretreatment, hydrolysis and fermentation. Production of bioethanol during fermentation depends on several factors such as temperature, sugar concentration, pH, fermentation time, agitation rate, and inoculum size. The efficiency and productivity of ethanol can be enhanced by immobilizing the yeast cells. This review highlights the different types of yeast strains, fermentation process, factors affecting bioethanol production and immobilization of yeasts for better bioethanol production.
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Affiliation(s)
- Siti Hajar Mohd Azhar
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Rahmath Abdulla
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
- Energy Research Unit, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Siti Azmah Jambo
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Hartinie Marbawi
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Jualang Azlan Gansau
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Ainol Azifa Mohd Faik
- Faculty of Science and Natural Resources, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
| | - Kenneth Francis Rodrigues
- Biotechnology Research Institute, Universiti Malaysia Sabah, Jalan UMS, 88400 Kota Kinabalu, Sabah, Malaysia
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Duwe A, Tippkötter N, Ulber R. Lignocellulose-Biorefinery: Ethanol-Focused. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2017; 166:177-215. [PMID: 29071401 DOI: 10.1007/10_2016_72] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The development prospects of the world markets for petroleum and other liquid fuels are diverse and partly contradictory. However, comprehensive changes for the energy supply of the future are essential. Notwithstanding the fact that there are still very large deposits of energy resources from a geological point of view, the finite nature of conventional oil reserves is indisputable. To reduce our dependence on oil, the EU, the USA, and other major economic zones rely on energy diversification. For this purpose, alternative materials and technologies are being sought, and is most obvious in the transport sector. The objective is to progressively replace fossil fuels with renewable and more sustainable fuels. In this respect, biofuels have a pre-eminent position in terms of their capability of blending with fossil fuels and being usable in existing cars without substantial modification. Ethanol can be considered as the primary renewable liquid fuel. In this chapter enzymes, micro-organisms, and processes for ethanol production based on renewable resources are described.
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Affiliation(s)
- A Duwe
- Institute of Bioprocess Engineering, University of Kaiserslautern, Gottlieb-Daimler-Str. 49, 67663, Kaiserslautern, Germany.
| | - N Tippkötter
- Institute of Bioprocess Engineering, University of Kaiserslautern, Gottlieb-Daimler-Str. 49, 67663, Kaiserslautern, Germany
| | - R Ulber
- Institute of Bioprocess Engineering, University of Kaiserslautern, Gottlieb-Daimler-Str. 49, 67663, Kaiserslautern, Germany
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Loaces I, Schein S, Noya F. Ethanol production by Escherichia coli from Arundo donax biomass under SSF, SHF or CBP process configurations and in situ production of a multifunctional glucanase and xylanase. BIORESOURCE TECHNOLOGY 2017; 224:307-313. [PMID: 27815044 DOI: 10.1016/j.biortech.2016.10.075] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 10/20/2016] [Accepted: 10/21/2016] [Indexed: 06/06/2023]
Abstract
Diluted acid or liquid hot water (LHW) pretreated Arundo donax biomass was converted into ethanol under separated hydrolysis and fermentation (SHF) or simultaneous saccharification and fermentation (SSF) using Escherichia coli as the fermentative organism. Up to 0.26gL-1h-1 and 25.0gL-1 of ethanol were obtained with diluted acid pretreated biomass under SSF compared to 0.17gL-1h-1 and 24gL-1 under SHF. LHW pretreated biomass elicited 25% lower yields on average. Saccharification was carried out with Cellic CTec2 cocktail. Alternatively, under a consolidated bioprocess (CBP) where the ethanologenic bacteria was complemented with a novel multifunctional glucanase and xylanase, ethanol concentration was 7.6gL-1 and 7.2gL-1 after 96h for dilute acid or LHW pretreated biomass, respectively, without any prior saccharification step. According to these results, a bacterial fermentative host combined with in situ enzyme expression can improve ethanol production from A. donax biomass.
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Affiliation(s)
- Inés Loaces
- Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.
| | - Sima Schein
- Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
| | - Francisco Noya
- Departamento de Bioquímica y Genómica Microbianas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
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25
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Cimini D, Argenzio O, D'Ambrosio S, Lama L, Finore I, Finamore R, Pepe O, Faraco V, Schiraldi C. Production of succinic acid from Basfia succiniciproducens up to the pilot scale from Arundo donax hydrolysate. BIORESOURCE TECHNOLOGY 2016; 222:355-360. [PMID: 27741473 DOI: 10.1016/j.biortech.2016.10.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2016] [Revised: 09/30/2016] [Accepted: 10/01/2016] [Indexed: 05/03/2023]
Abstract
In the present work the recently isolated strain Basfia succiniciproducens BPP7 was evaluated for the production of succinic acid up to the pilot fermentation scale in separate hydrolysis and fermentation experiments on Arundo donax, a non-food dedicated energy crop. An average concentration of about 17g/L of succinic acid and a yield on consumed sugars of 0.75mol/mol were obtained demonstrating strain potential for further process improvement. Small scale experiments indicated that the concentration of acetic acid in the medium is crucial to improve productivity; on the other hand, interestingly, short-term (24h) adaptation to higher acetic acid concentrations, and strain recovery, were also observed.
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Affiliation(s)
- Donatella Cimini
- Second University of Naples, Department of Experimental Medicine, Via de Crecchio 7, 80138 Naples, Italy.
| | - Ottavia Argenzio
- Second University of Naples, Department of Experimental Medicine, Via de Crecchio 7, 80138 Naples, Italy
| | - Sergio D'Ambrosio
- Second University of Naples, Department of Experimental Medicine, Via de Crecchio 7, 80138 Naples, Italy
| | - Licia Lama
- National Research Council, Institute of Biomolecular Chemistry (ICB), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Ilaria Finore
- National Research Council, Institute of Biomolecular Chemistry (ICB), Via Campi Flegrei 34, 80078 Pozzuoli, Naples, Italy
| | - Rosario Finamore
- Second University of Naples, Department of Experimental Medicine, Via de Crecchio 7, 80138 Naples, Italy
| | - Olimpia Pepe
- Department of Agricultural Sciences, Division of Microbiology, University of Naples Federico II, Via Università 100, 80055 Portici (Naples), Italy
| | - Vincenza Faraco
- Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario Monte S. Angelo, via Cinthia, 4, 80126 Naples, Italy
| | - Chiara Schiraldi
- Second University of Naples, Department of Experimental Medicine, Via de Crecchio 7, 80138 Naples, Italy
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26
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Lignocellulosic Ethanol Production from the Recovery of Stranded Driftwood Residues. ENERGIES 2016. [DOI: 10.3390/en9080634] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Gherbin P, Milan S, Mercurio G, Scopa A. Shooting of giant reed (Arundo donax L.) stem cuttings in cold greenhouse. INTERNATIONAL JOURNAL OF PLANT BIOLOGY 2016. [DOI: 10.4081/pb.2016.6294] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
The increasing interest in<em> Arundo donax,</em> a perennial lignocellulosic species only reproducing by propagation, requires the setup of cheap, simple and reliable techniques. Considering these targets, stem cutting offers considerable advantages. The present investigation aimed to compare: i) plants obtained by different propagation methods (by rhizome and micropropagation mother plants); ii) plants obtained by stem cuttings from basal, central and apical parts of the stem; iii) different planting periods (spring, summer, autumn). The obtained results showed that the number of new shoots from stem buds was: i) higher in the spring and lower in the summer planting period; ii) higher from cuttings obtained by micropropagated than rhizome mother plants, both in spring and summer plantings; iii) decreasing passing from the basal to the apical stem portion; iv) partly unexpressed in the autumn planting period; v) lower from one-year stem cuttings as compared to two-year stem cuttings.
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Anasontzis GE, Kourtoglou E, Villas-Boâs SG, Hatzinikolaou DG, Christakopoulos P. Metabolic Engineering of Fusarium oxysporum to Improve Its Ethanol-Producing Capability. Front Microbiol 2016; 7:632. [PMID: 27199958 PMCID: PMC4854878 DOI: 10.3389/fmicb.2016.00632] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 04/18/2016] [Indexed: 12/13/2022] Open
Abstract
Fusarium oxysporum is one of the few filamentous fungi capable of fermenting ethanol directly from plant cell wall biomass. It has the enzymatic toolbox necessary to break down biomass to its monosaccharides and, under anaerobic and microaerobic conditions, ferments them to ethanol. Although these traits could enable its use in consolidated processes and thus bypass some of the bottlenecks encountered in ethanol production from lignocellulosic material when Saccharomyces cerevisiae is used—namely its inability to degrade lignocellulose and to consume pentoses—two major disadvantages of F. oxysporum compared to the yeast—its low growth rate and low ethanol productivity—hinder the further development of this process. We had previously identified phosphoglucomutase and transaldolase, two major enzymes of glucose catabolism and the pentose phosphate pathway, as possible bottlenecks in the metabolism of the fungus and we had reported the effect of their constitutive production on the growth characteristics of the fungus. In this study, we investigated the effect of their constitutive production on ethanol productivity under anaerobic conditions. We report an increase in ethanol yield and a concomitant decrease in acetic acid production. Metabolomics analysis revealed that the genetic modifications applied did not simply accelerate the metabolic rate of the microorganism; they also affected the relative concentrations of the various metabolites suggesting an increased channeling toward the chorismate pathway, an activation of the γ-aminobutyric acid shunt, and an excess in NADPH regeneration.
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Affiliation(s)
- George E Anasontzis
- Microbial Biotechnology Unit, Sector of Botany, Department of Biology, National and Kapodistrian University of Athens Zografou, Greece
| | - Elisavet Kourtoglou
- BIOtechMASS Unit, Biotechnology Laboratory, School of Chemical Engineering, National Technical University of Athens Zografou, Greece
| | - Silas G Villas-Boâs
- Centre for Microbial Innovation, School of Biological Sciences, University of Auckland Auckland, New Zealand
| | - Dimitris G Hatzinikolaou
- Microbial Biotechnology Unit, Sector of Botany, Department of Biology, National and Kapodistrian University of Athens Zografou, Greece
| | - Paul Christakopoulos
- Biochemical and Chemical Process Engineering, Division of Sustainable Process Engineering, Department of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology Luleå, Sweden
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Liu YK, Lien PM. Bioethanol production from potato starch by a novel vertical mass-flow type bioreactor with a co-cultured-cell strategy. J Taiwan Inst Chem Eng 2016. [DOI: 10.1016/j.jtice.2016.01.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Schell DJ, Dowe N, Chapeaux A, Nelson RS, Jennings EW. Accounting for all sugars produced during integrated production of ethanol from lignocellulosic biomass. BIORESOURCE TECHNOLOGY 2016; 205:153-158. [PMID: 26826954 DOI: 10.1016/j.biortech.2016.01.024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2015] [Revised: 01/05/2016] [Accepted: 01/06/2016] [Indexed: 06/05/2023]
Abstract
Accurate mass balance and conversion data from integrated operation is needed to fully elucidate the economics of biofuel production processes. This study explored integrated conversion of corn stover to ethanol and highlights techniques for accurate yield calculations. Acid pretreated corn stover (PCS) produced in a pilot-scale reactor was enzymatically hydrolyzed and the resulting sugars were fermented to ethanol by the glucose-xylose fermenting bacteria, Zymomonas mobilis 8b. The calculations presented here account for high solids operation and oligomeric sugars produced during pretreatment, enzymatic hydrolysis, and fermentation, which, if not accounted for, leads to overestimating ethanol yields. The calculations are illustrated for enzymatic hydrolysis and fermentation of PCS at 17.5% and 20.0% total solids achieving 80.1% and 77.9% conversion of cellulose and xylan to ethanol and ethanol titers of 63g/L and 69g/L, respectively. These procedures will be employed in the future and the resulting information used for techno-economic analysis.
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Affiliation(s)
- Daniel J Schell
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA.
| | - Nancy Dowe
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
| | | | - Robert S Nelson
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
| | - Edward W Jennings
- National Bioenergy Center, National Renewable Energy Laboratory, 15013 Denver West Parkway, Golden, CO 80401, USA
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Agirre J, Ariza A, Offen WA, Turkenburg JP, Roberts SM, McNicholas S, Harris PV, McBrayer B, Dohnalek J, Cowtan KD, Davies GJ, Wilson KS. Three-dimensional structures of two heavily N-glycosylated Aspergillus sp. family GH3 β-D-glucosidases. Acta Crystallogr D Struct Biol 2016; 72:254-65. [PMID: 26894673 PMCID: PMC4756609 DOI: 10.1107/s2059798315024237] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2015] [Accepted: 12/16/2015] [Indexed: 01/25/2023] Open
Abstract
The industrial conversion of cellulosic plant biomass into useful products such as biofuels is a major societal goal. These technologies harness diverse plant degrading enzymes, classical exo- and endo-acting cellulases and, increasingly, cellulose-active lytic polysaccharide monooxygenases, to deconstruct the recalcitrant β-D-linked polysaccharide. A major drawback with this process is that the exo-acting cellobiohydrolases suffer from severe inhibition from their cellobiose product. β-D-Glucosidases are therefore important for liberating glucose from cellobiose and thereby relieving limiting product inhibition. Here, the three-dimensional structures of two industrially important family GH3 β-D-glucosidases from Aspergillus fumigatus and A. oryzae, solved by molecular replacement and refined at 1.95 Å resolution, are reported. Both enzymes, which share 78% sequence identity, display a three-domain structure with the catalytic domain at the interface, as originally shown for barley β-D-glucan exohydrolase, the first three-dimensional structure solved from glycoside hydrolase family GH3. Both enzymes show extensive N-glycosylation, with only a few external sites being truncated to a single GlcNAc molecule. Those glycans N-linked to the core of the structure are identified purely as high-mannose trees, and establish multiple hydrogen bonds between their sugar components and adjacent protein side chains. The extensive glycans pose special problems for crystallographic refinement, and new techniques and protocols were developed especially for this work. These protocols ensured that all of the D-pyranosides in the glycosylation trees were modelled in the preferred minimum-energy (4)C1 chair conformation and should be of general application to refinements of other crystal structures containing O- or N-glycosylation. The Aspergillus GH3 structures, in light of other recent three-dimensional structures, provide insight into fungal β-D-glucosidases and provide a platform on which to inform and inspire new generations of variant enzymes for industrial application.
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Affiliation(s)
- Jon Agirre
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Antonio Ariza
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Wendy A. Offen
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Johan P. Turkenburg
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Shirley M. Roberts
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Stuart McNicholas
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | | | | | - Jan Dohnalek
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Kevin D. Cowtan
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Gideon J. Davies
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
| | - Keith S. Wilson
- York Structural Biology Laboratory, Department of Chemistry, The University of York, York YO10 5DD, England
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Kim SM, Dien BS, Singh V. Promise of combined hydrothermal/chemical and mechanical refining for pretreatment of woody and herbaceous biomass. BIOTECHNOLOGY FOR BIOFUELS 2016; 9:97. [PMID: 27141232 PMCID: PMC4852465 DOI: 10.1186/s13068-016-0505-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 04/12/2016] [Indexed: 05/07/2023]
Abstract
Production of advanced biofuels from woody and herbaceous feedstocks is moving into commercialization. Biomass needs to be pretreated to overcome the physicochemical properties of biomass that hinder enzyme accessibility, impeding the conversion of the plant cell walls to fermentable sugars. Pretreatment also remains one of the most costly unit operations in the process and among the most critical because it is the source of chemicals that inhibit enzymes and microorganisms and largely determines enzyme loading and sugar yields. Pretreatments are categorized into hydrothermal (aqueous)/chemical, physical, and biological pretreatments, and the mechanistic details of which are briefly outlined in this review. To leverage the synergistic effects of different pretreatment methods, conducting two or more pretreatments consecutively has gained attention. Especially, combining hydrothermal/chemical pretreatment and mechanical refining, a type of physical pretreatment, has the potential to be applied to an industrial plant. Here, the effects of the combined pretreatment (combined hydrothermal/chemical pretreatment and mechanical refining) on energy consumption, physical structure, sugar yields, and enzyme dosage are summarized.
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Affiliation(s)
- Sun Min Kim
- />Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
| | - Bruce S. Dien
- />Bioenergy Research Unit, Agricultural Research Service, USDA, National Center for Agricultural Utilization Research, Peoria, IL 61604 USA
| | - Vijay Singh
- />Department of Agricultural and Biological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801 USA
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Paulova L, Patakova P, Branska B, Rychtera M, Melzoch K. Lignocellulosic ethanol: Technology design and its impact on process efficiency. Biotechnol Adv 2015; 33:1091-107. [DOI: 10.1016/j.biotechadv.2014.12.002] [Citation(s) in RCA: 117] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Revised: 12/01/2014] [Accepted: 12/03/2014] [Indexed: 12/27/2022]
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Eldalatony MM, Kabra AN, Hwang JH, Govindwar SP, Kim KH, Kim H, Jeon BH. Pretreatment of microalgal biomass for enhanced recovery/extraction of reducing sugars and proteins. Bioprocess Biosyst Eng 2015; 39:95-103. [PMID: 26508325 DOI: 10.1007/s00449-015-1493-5] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 10/19/2015] [Indexed: 10/22/2022]
Abstract
Microalgae species including Chlamydomonas mexicana, Micractinium reisseri, Scenedesmus obliquus and Tribonema aequale were cultivated in batch cultures, and their biochemical composition was determined. C. mexicana showed the highest carbohydrate content of 52.6% and was selected for further study. Sonication pretreatment under optimum conditions (at 40 kHz, 2.2 Kw, 50 °C for 15 min) released 74 ± 2.7 mg g(-1) of total reducing sugars (TRS) of dry cell weight, while the combined sonication and enzymatic hydrolysis treatment enhanced the TRS yield by fourfold (280.5 ± 4.9 mg g(-1)). The optimal ratio of enzyme [E]:substrate [S] for maximum TRS yield was [1]:[5] at 50 °C and pH 5. Combined sonication and hydrolysis treatment released 7.3% (27.1 ± 0.9 mg g(-1)) soluble protein of dry cell weight, and further fermentation of the dissolved carbohydrate fraction enhanced the soluble protein content up to 56% (228.4 mg g(-1)) of total protein content. Scanning and transmission electron microscopic analyses indicated that microalgae cells were significantly disrupted by the combined sonication and enzyme hydrolysis treatment. This study indicates that pretreatment and subsequent fermentation of the microalgal biomass enhance the recovery of carbohydrates and proteins which can be used as feedstocks for generation of biofuels.
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Affiliation(s)
- Marwa M Eldalatony
- Department of Natural Resources and Environmental Engineering, Hanyang University, Seoul, 133-791, South Korea
| | - Akhil N Kabra
- Department of Biochemistry, Shivaji University, Vidyanagar, Kolhapur, Maharashtra, 416004, India
| | - Jae-Hoon Hwang
- Swette Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, P.O. Box 875701, Tempe, AZ, 85287-5701, USA
| | - Sanjay P Govindwar
- Department of Biochemistry, Shivaji University, Vidyanagar, Kolhapur, Maharashtra, 416004, India
| | - Ki-Hyun Kim
- Department of Civil and Environmental Engineering, Hanyang University, Seoul, 133-791, South Korea
| | - Hoo Kim
- Department of Natural Resources and Environmental Engineering, Hanyang University, Seoul, 133-791, South Korea
| | - Byong-Hun Jeon
- Department of Natural Resources and Environmental Engineering, Hanyang University, Seoul, 133-791, South Korea.
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Wang M, Lai GL, Nie Y, Geng S, Liu L, Zhu B, Shi Z, Wu XL. Synergistic function of four novel thermostable glycoside hydrolases from a long-term enriched thermophilic methanogenic digester. Front Microbiol 2015; 6:509. [PMID: 26052323 PMCID: PMC4441150 DOI: 10.3389/fmicb.2015.00509] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2015] [Accepted: 05/08/2015] [Indexed: 12/25/2022] Open
Abstract
In biofuel production from lignocellulose, low thermostability and product inhibition strongly restrict the enzyme activities and production process. Application of multiple thermostable glycoside hydrolases, forming an enzyme "cocktail", can result in a synergistic action and therefore improve production efficiency and reduce operational costs. Therefore, increasing enzyme thermostabilities and compatibility are important for the biofuel industry. In this study, we reported the screening, cloning and biochemical characterization of four novel thermostable lignocellulose hydrolases from a metagenomic library of a long-term dry thermophilic methanogenic digester community, which were highly compatible with optimal conditions and specific activities. The optimal temperatures of the four enzymes, β-xylosidase, xylanase, β-glucosidase, and cellulase ranged from 60 to 75°C, and over 80% residual activities were observed after 2 h incubation at 50°C. Mixtures of these hydrolases retained high residual synergistic activities after incubation with cellulose, xylan, and steam-exploded corncob at 50°C for 72 h. In addition, about 55% dry weight of steam-exploded corncob was hydrolyzed to glucose and xylose by the synergistic action of the four enzymes at 50°C for 48 h. This work suggested that since different enzymes from a same ecosystem could be more compatible, screening enzymes from a long-term enriching community could be a favorable strategy.
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Affiliation(s)
- Meng Wang
- School of Biotechnology, Jiangnan University Wuxi, China ; Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China
| | - Guo-Li Lai
- Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China ; Institute of Engineering (Baotou), College of Engineering, Peking University Baotou, China
| | - Yong Nie
- Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China ; Institute of Engineering (Baotou), College of Engineering, Peking University Baotou, China
| | - Shuang Geng
- Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China
| | - Liming Liu
- School of Biotechnology, Jiangnan University Wuxi, China
| | - Baoli Zhu
- Institute of Microbiology, Chinese Academy of Sciences Beijing, China
| | - Zhongping Shi
- School of Biotechnology, Jiangnan University Wuxi, China
| | - Xiao-Lei Wu
- Department of Energy and Resources Engineering, College of Engineering, Peking University Beijing, China ; Institute of Engineering (Baotou), College of Engineering, Peking University Baotou, China
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Potential of giant reed (Arundo donax L.) for second generation ethanol production. ELECTRON J BIOTECHN 2015. [DOI: 10.1016/j.ejbt.2014.11.002] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Faria NT, Santos M, Ferreira C, Marques S, Ferreira FC, Fonseca C. Conversion of cellulosic materials into glycolipid biosurfactants, mannosylerythritol lipids, by Pseudozyma spp. under SHF and SSF processes. Microb Cell Fact 2014; 13:155. [PMID: 25366184 PMCID: PMC4226859 DOI: 10.1186/s12934-014-0155-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Accepted: 10/20/2014] [Indexed: 01/28/2023] Open
Abstract
Background Mannosylerythritol lipids (MEL) are glycolipids with unique biosurfactant properties and are produced by Pseudozyma spp. from different substrates, preferably vegetable oils, but also sugars, glycerol or hydrocarbons. However, solvent intensive downstream processing and the relatively high prices of raw materials currently used for MEL production are drawbacks in its sustainable commercial deployment. The present work aims to demonstrate MEL production from cellulosic materials and investigate the requirements and consequences of combining commercial cellulolytic enzymes and Pseudozyma spp. under separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF) processes. Results MEL was produced from cellulosic substrates, Avicel® as reference (>99% cellulose) and hydrothermally pretreated wheat straw, using commercial cellulolytic enzymes (Celluclast 1.5 L® and Novozyme 188®) and Pseudozyma antarctica PYCC 5048T or Pseudozyma aphidis PYCC 5535T. The strategies included SHF, SSF and fed-batch SSF with pre-hydrolysis. While SSF was isothermal at 28°C, in SHF and fed-batch SSF, yeast fermentation was preceded by an enzymatic (pre-)hydrolysis step at 50°C for 48 h. Pseudozyma antarctica showed the highest MEL yields from both cellulosic substrates, reaching titres of 4.0 and 1.4 g/l by SHF of Avicel® and wheat straw (40 g/l glucan), respectively, using enzymes at low dosage (3.6 and 8.5 FPU/gglucan at 28°C and 50°C, respectively) with prior dialysis. Higher MEL titres were obtained by fed-batch SSF with pre-hydrolysis, reaching 4.5 and 2.5 g/l from Avicel® and wheat straw (80 g/l glucan), respectively. Conclusions This work reports for the first time MEL production from cellulosic materials. The process was successfully performed through SHF, SSF or Fed-batch SSF, requiring, for maximal performance, dialysed commercial cellulolytic enzymes. The use of inexpensive lignocellulosic substrates associated to straightforward downstream processing from sugary broths is expected to have a great impact in the economy of MEL production for the biosurfactant market, inasmuch as low enzyme dosage is sufficient for good systems performance.
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Affiliation(s)
- Nuno Torres Faria
- Department of Bioengineering and IBB - Institute for Bioengineering and Bioscience, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal. .,MIT-Portugal Program, 77 Massachusetts Avenue, E40-221, Cambridge, MA, 02139, USA. .,Laboratório Nacional de Energia e Geologia, I.P, Unidade de Bioenergia, Estrada do Paço do Lumiar 22, 1649-038, Lisboa, Portugal.
| | - Marisa Santos
- Department of Bioengineering and IBB - Institute for Bioengineering and Bioscience, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal. .,MIT-Portugal Program, 77 Massachusetts Avenue, E40-221, Cambridge, MA, 02139, USA.
| | - Carla Ferreira
- Laboratório Nacional de Energia e Geologia, I.P, Unidade de Bioenergia, Estrada do Paço do Lumiar 22, 1649-038, Lisboa, Portugal.
| | - Susana Marques
- Laboratório Nacional de Energia e Geologia, I.P, Unidade de Bioenergia, Estrada do Paço do Lumiar 22, 1649-038, Lisboa, Portugal.
| | - Frederico Castelo Ferreira
- Department of Bioengineering and IBB - Institute for Bioengineering and Bioscience, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001, Lisboa, Portugal.
| | - César Fonseca
- Laboratório Nacional de Energia e Geologia, I.P, Unidade de Bioenergia, Estrada do Paço do Lumiar 22, 1649-038, Lisboa, Portugal.
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Li X, Lu J, Zhao J, Qu Y. Characteristics of corn stover pretreated with liquid hot water and fed-batch semi-simultaneous saccharification and fermentation for bioethanol production. PLoS One 2014; 9:e95455. [PMID: 24763192 PMCID: PMC3998958 DOI: 10.1371/journal.pone.0095455] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 03/26/2014] [Indexed: 11/22/2022] Open
Abstract
Corn stover is a promising feedstock for bioethanol production because of its abundant availability in China. To obtain higher ethanol concentration and higher ethanol yield, liquid hot water (LHW) pretreatment and fed-batch semi-simultaneous saccharification and fermentation (S-SSF) were used to enhance the enzymatic digestibility of corn stover and improve bioconversion of cellulose to ethanol. The results show that solid residues from LHW pretreatment of corn stover can be effectively converted into ethanol at severity factors ranging from 3.95 to 4.54, and the highest amount of xylan removed was approximately 89%. The ethanol concentrations of 38.4 g/L and 39.4 g/L as well as ethanol yields of 78.6% and 79.7% at severity factors of 3.95 and 4.54, respectively, were obtained by fed-batch S-SSF in an optimum conditions (initial substrate consistency of 10%, and 6.1% solid residues added into system at the prehydrolysis time of 6 h). The changes in surface morphological structure, specific surface area, pore volume and diameter of corn stover subjected to LHW process were also analyzed for interpreting the possible improvement mechanism.
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Affiliation(s)
- Xuezhi Li
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Jie Lu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
- Dalian Polytechnic University, Dalian, China
| | - Jian Zhao
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
| | - Yinbo Qu
- State Key Laboratory of Microbial Technology, Shandong University, Jinan, China
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Cotana F, Cavalaglio G, Gelosia M, Nicolini A, Coccia V, Petrozzi A. Production of Bioethanol in a Second Generation Prototype from Pine Wood Chips. ACTA ACUST UNITED AC 2014. [DOI: 10.1016/j.egypro.2014.01.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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40
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Nsanganwimana F, Marchand L, Douay F, Mench M. Arundo donax L., a candidate for phytomanaging water and soils contaminated by trace elements and producing plant-based feedstock. A review. INTERNATIONAL JOURNAL OF PHYTOREMEDIATION 2014; 16:982-1017. [PMID: 24933898 DOI: 10.1080/15226514.2013.810580] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Plants and associated microorganisms are used to remediate anthropogenic metal(loid) contamination of water, soils and sediments. This review focuses on the potential of Arundo donax L. (Giant reed) for alleviating risks due to soils, water, and sediments contaminated by trace elements (TE), with emphasis on its advantages and limits over macrophytes and perennial grasses used for bioenergy and plant-based feedstock. Arundo donax is relevant to phytomanage TE-contaminated matrices, notably in its native area, as it possesses characteristics of large biomass production even under nutrient and abiotic stresses, fast growth rate, TE tolerance and accumulation mainly in below ground plant parts. Cultivating A. donax on contaminated lands and in constructed wetlands can contribute to increase land availability and limit the food vs. plant-based feedstock controversy. To gain more tools for decision-taking and sustainable management,further researches on A. donax should focus on: interactions between roots, TE exposure, and rhizosphere and endophytic microorganisms; biomass response to (a)biotic factors; sustainable agricultural practices on marginal and contaminated land; integration into local, efficient, energy and biomass conversion chains with concern to biomass quality and production; Life-Cycle Assessment including contaminant behavior, as well as environmental, agricultural and socio-economic benefits and drawbacks.
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Mutturi S, Lidén G. Model-based estimation of optimal temperature profile during simultaneous saccharification and fermentation ofArundo donax. Biotechnol Bioeng 2013; 111:866-75. [DOI: 10.1002/bit.25165] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 10/30/2013] [Accepted: 11/18/2013] [Indexed: 11/09/2022]
Affiliation(s)
- Sarma Mutturi
- Department of Chemical Engineering; Lund University; P.O. Box 124 221 00 Lund Sweden
| | - Gunnar Lidén
- Department of Chemical Engineering; Lund University; P.O. Box 124 221 00 Lund Sweden
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Ask M, Bettiga M, Duraiswamy VR, Olsson L. Pulsed addition of HMF and furfural to batch-grown xylose-utilizing Saccharomyces cerevisiae results in different physiological responses in glucose and xylose consumption phase. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:181. [PMID: 24341320 PMCID: PMC3878631 DOI: 10.1186/1754-6834-6-181] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Accepted: 11/29/2013] [Indexed: 05/07/2023]
Abstract
BACKGROUND Pretreatment of lignocellulosic biomass generates a number of undesired degradation products that can inhibit microbial metabolism. Two of these compounds, the furan aldehydes 5-hydroxymethylfurfural (HMF) and 2-furaldehyde (furfural), have been shown to be an impediment for viable ethanol production. In the present study, HMF and furfural were pulse-added during either the glucose or the xylose consumption phase in order to dissect the effects of these inhibitors on energy state, redox metabolism, and gene expression of xylose-consuming Saccharomyces cerevisiae. RESULTS Pulsed addition of 3.9 g L-1 HMF and 1.2 g L-1 furfural during either the glucose or the xylose consumption phase resulted in distinct physiological responses. Addition of furan aldehydes in the glucose consumption phase was followed by a decrease in the specific growth rate and the glycerol yield, whereas the acetate yield increased 7.3-fold, suggesting that NAD(P)H for furan aldehyde conversion was generated by acetate synthesis. No change in the intracellular levels of NAD(P)H was observed 1 hour after pulsing, whereas the intracellular concentration of ATP increased by 58%. An investigation of the response at transcriptional level revealed changes known to be correlated with perturbations in the specific growth rate, such as protein and nucleotide biosynthesis. Addition of furan aldehydes during the xylose consumption phase brought about an increase in the glycerol and acetate yields, whereas the xylitol yield was severely reduced. The intracellular concentrations of NADH and NADPH decreased by 58 and 85%, respectively, hence suggesting that HMF and furfural drained the cells of reducing power. The intracellular concentration of ATP was reduced by 42% 1 hour after pulsing of inhibitors, suggesting that energy-requiring repair or maintenance processes were activated. Transcriptome profiling showed that NADPH-requiring processes such as amino acid biosynthesis and sulfate and nitrogen assimilation were induced 1 hour after pulsing. CONCLUSIONS The redox and energy metabolism were found to be more severely affected after pulsing of furan aldehydes during the xylose consumption phase than during glucose consumption. Conceivably, this discrepancy resulted from the low xylose utilization rate, hence suggesting that xylose metabolism is a feasible target for metabolic engineering of more robust xylose-utilizing yeast strains.
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Affiliation(s)
- Magnus Ask
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - Maurizio Bettiga
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - Varuni Raju Duraiswamy
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - Lisbeth Olsson
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
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Engineering glutathione biosynthesis of Saccharomyces cerevisiae increases robustness to inhibitors in pretreated lignocellulosic materials. Microb Cell Fact 2013; 12:87. [PMID: 24083827 PMCID: PMC3817835 DOI: 10.1186/1475-2859-12-87] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 09/26/2013] [Indexed: 11/11/2022] Open
Abstract
Background Production of bioethanol from lignocellulosic biomass requires the development of robust microorganisms that can tolerate the stressful conditions prevailing in lignocellulosic hydrolysates. Several inhibitors are known to affect the redox metabolism of cells. In this study, Saccharomyces cerevisiae was engineered for increased robustness by modulating the redox state through overexpression of GSH1, CYS3 and GLR1, three genes involved in glutathione (GSH) metabolism. Results Overexpression constructs were stably integrated into the genome of the host strains yielding five strains overexpressing GSH1, GSH1/CYS3, GLR1, GSH1/GLR1 and GSH1/CYS3/GLR1. Overexpression of GSH1 resulted in a 42% increase in the total intracellular glutathione levels compared to the wild type. Overexpression of GSH1/CYS3, GSH1/GLR1 and GSH1/CYS3/GLR1 all resulted in equal or less intracellular glutathione concentrations than overexpression of only GSH1, although higher than the wild type. GLR1 overexpression resulted in similar total glutathione levels as the wild type. Surprisingly, all recombinant strains had a lower [reduced glutathione]:[oxidized glutathione] ratio (ranging from 32–67) than the wild type strain (88), suggesting a more oxidized intracellular environment in the engineered strains. When considering the glutathione half-cell redox potential (Ehc), the difference between the strains was less pronounced. Ehc for the recombinant strains ranged from -225 to -216 mV, whereas for the wild type it was estimated to -225 mV. To test whether the recombinant strains were more robust in industrially relevant conditions, they were evaluated in simultaneous saccharification and fermentation (SSF) of pretreated spruce. All strains carrying the GSH1 overexpression construct performed better than the wild type in terms of ethanol yield and conversion of furfural and HMF. The strain overexpressing GSH1/GLR1 produced 14.0 g L-1 ethanol in 48 hours corresponding to an ethanol yield on hexoses of 0.17 g g-1; while the wild type produced 8.2 g L-1 ethanol in 48 hours resulting in an ethanol yield on hexoses of 0.10 g g-1. Conclusions In this study, we showed that engineering of the redox state by modulating the levels of intracellular glutathione results in increased robustness of S. cerevisiae in SSF of pretreated spruce.
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Wang G, Liu C, Hong J, Ma Y, Zhang K, Huang X, Zou S, Zhang M. Comparison of process configurations for ethanol production from acid- and alkali-pretreated corncob by Saccharomyces cerevisiae strains with and without β-glucosidase expression. BIORESOURCE TECHNOLOGY 2013; 142:154-161. [PMID: 23735797 DOI: 10.1016/j.biortech.2013.05.033] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Revised: 05/07/2013] [Accepted: 05/08/2013] [Indexed: 06/02/2023]
Abstract
β-Glucosidase was shown to have synergistic effects with commercial cellulase in the hydrolysis of acid- and alkali-pretreated corncob, especially at the dose of 5 U/g biomass and 5 or 10 FPU/g biomass. An integrating yeast strain 45# expressing β-glucosidase was constructed that utilized cellobiose quickly and efficiently. Process configurations were compared under conditions of 10% solid content, 10 FPU cellulase/g biomass, 5 U β-glucosidase/g biomass (only used for parental strain W303-1A), 1g/kg yeast loading and 3.3g/kg urea supplementation. While separate hydrolysis and fermentation was optimal for W303-1A and the ethanol titer and yield reached 3.22 g/100g and 75.6% (expressed as a percentage of the theoretical yield), respectively, simultaneous saccharification and fermentation was optimal for strain 45# and the ethanol titer and yield reached 3.31 g/100g and 77.7%, respectively. These results are valuable in optimization of the process configuration and improving the yeast strain selected for cellulosic ethanol production.
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Affiliation(s)
- Guoqiang Wang
- Tianjin R&D Center for Petrochemical Technology, Tianjin University, Tianjin 300072, China
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Demeke MM, Dietz H, Li Y, Foulquié-Moreno MR, Mutturi S, Deprez S, Den Abt T, Bonini BM, Liden G, Dumortier F, Verplaetse A, Boles E, Thevelein JM. Development of a D-xylose fermenting and inhibitor tolerant industrial Saccharomyces cerevisiae strain with high performance in lignocellulose hydrolysates using metabolic and evolutionary engineering. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:89. [PMID: 23800147 PMCID: PMC3698012 DOI: 10.1186/1754-6834-6-89] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2013] [Accepted: 06/12/2013] [Indexed: 05/04/2023]
Abstract
BACKGROUND The production of bioethanol from lignocellulose hydrolysates requires a robust, D-xylose-fermenting and inhibitor-tolerant microorganism as catalyst. The purpose of the present work was to develop such a strain from a prime industrial yeast strain, Ethanol Red, used for bioethanol production. RESULTS An expression cassette containing 13 genes including Clostridium phytofermentans XylA, encoding D-xylose isomerase (XI), and enzymes of the pentose phosphate pathway was inserted in two copies in the genome of Ethanol Red. Subsequent EMS mutagenesis, genome shuffling and selection in D-xylose-enriched lignocellulose hydrolysate, followed by multiple rounds of evolutionary engineering in complex medium with D-xylose, gradually established efficient D-xylose fermentation. The best-performing strain, GS1.11-26, showed a maximum specific D-xylose consumption rate of 1.1 g/g DW/h in synthetic medium, with complete attenuation of 35 g/L D-xylose in about 17 h. In separate hydrolysis and fermentation of lignocellulose hydrolysates of Arundo donax (giant reed), spruce and a wheat straw/hay mixture, the maximum specific D-xylose consumption rate was 0.36, 0.23 and 1.1 g/g DW inoculum/h, and the final ethanol titer was 4.2, 3.9 and 5.8% (v/v), respectively. In simultaneous saccharification and fermentation of Arundo hydrolysate, GS1.11-26 produced 32% more ethanol than the parent strain Ethanol Red, due to efficient D-xylose utilization. The high D-xylose fermentation capacity was stable after extended growth in glucose. Cell extracts of strain GS1.11-26 displayed 17-fold higher XI activity compared to the parent strain, but overexpression of XI alone was not enough to establish D-xylose fermentation. The high D-xylose consumption rate was due to synergistic interaction between the high XI activity and one or more mutations in the genome. The GS1.11-26 had a partial respiratory defect causing a reduced aerobic growth rate. CONCLUSIONS An industrial yeast strain for bioethanol production with lignocellulose hydrolysates has been developed in the genetic background of a strain widely used for commercial bioethanol production. The strain uses glucose and D-xylose with high consumption rates and partial cofermentation in various lignocellulose hydrolysates with very high ethanol yield. The GS1.11-26 strain shows highly promising potential for further development of an all-round robust yeast strain for efficient fermentation of various lignocellulose hydrolysates.
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Affiliation(s)
- Mekonnen M Demeke
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Heiko Dietz
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany
| | - Yingying Li
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - María R Foulquié-Moreno
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Sarma Mutturi
- Department of Chemical Engineering, Lund University, P.O. Box 124, 22100 Lund, Sweden
| | - Sylvie Deprez
- Laboratory of Enzyme, Fermentation and Brewing Technology, KAHO Sint-Lieven University College, KU Leuven Association, Gebroeders De Smetstraat 1, 9000, Ghent, Flanders, Belgium
| | - Tom Den Abt
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Beatriz M Bonini
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Gunnar Liden
- Department of Chemical Engineering, Lund University, P.O. Box 124, 22100 Lund, Sweden
| | - Françoise Dumortier
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
| | - Alex Verplaetse
- Laboratory of Enzyme, Fermentation and Brewing Technology, KAHO Sint-Lieven University College, KU Leuven Association, Gebroeders De Smetstraat 1, 9000, Ghent, Flanders, Belgium
| | - Eckhard Boles
- Institute of Molecular Biosciences, Goethe-University Frankfurt, Max-von-Laue-Str. 9, D-60438 Frankfurt am Main, Germany
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Belgium
- Department of Molecular Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven, Heverlee, Flanders, Belgium
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You TT, Mao JZ, Yuan TQ, Wen JL, Xu F. Structural elucidation of the lignins from stems and foliage of Arundo donax Linn. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2013; 61:5361-5370. [PMID: 23646880 DOI: 10.1021/jf401277v] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
As one of the potential energy crops, Arundo donax Linn. is a renewable source for the production of biofuels and bioproducts. In the present study, milled wood lignin (MWL) and alkaline lignin (AL) from stems and foliage of A. donax were isolated and characterized by FT-IR spectroscopy, UV spectroscopy, GPC, ³¹P NMR, 2D HSQC NMR, and DFRC. The results indicated that both stem and foliage lignins were HGS type lignins. The semiquantitative HSQC spectra analysis demonstrated a predominance of β-O-4' aryl ether linkages (71-82%), followed by β-β', β-5', β-1', and α,β-diaryl ethers linkages in the lignins. Compared to stem lignins, foliage lignins had less β-O-4' alkyl-aryl ethers, lower weight-average molecular weight, less phenolic OH, more H units, and lower S/G ratio. Moreover, tricin was found to incorporate into the foliage lignins (higher content of condensed G units) in significant amounts and might be alkaline-stable.
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Affiliation(s)
- Ting-Ting You
- Beijing Key Laboratory of Lignocellulosic Chemistry, Beijing Forestry University , Beijing, China
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Ask M, Bettiga M, Mapelli V, Olsson L. The influence of HMF and furfural on redox-balance and energy-state of xylose-utilizing Saccharomyces cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:22. [PMID: 23409974 PMCID: PMC3598934 DOI: 10.1186/1754-6834-6-22] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 02/12/2013] [Indexed: 05/13/2023]
Abstract
BACKGROUND Pretreatment of biomass for lignocellulosic ethanol production generates compounds that can inhibit microbial metabolism. The furan aldehydes hydroxymethylfurfural (HMF) and furfural have received increasing attention recently. In the present study, the effects of HMF and furfural on redox metabolism, energy metabolism and gene expression were investigated in anaerobic chemostats where the inhibitors were added to the feed-medium. RESULTS By cultivating the xylose-utilizing Saccharomyces cerevisiae strain VTT C-10883 in the presence of HMF and furfural, it was found that the intracellular concentrations of the redox co-factors and the catabolic and anabolic reduction charges were significantly lower in the presence of furan aldehydes than in cultivations without inhibitors. The catabolic reduction charge decreased from 0.13(±0.005) to 0.08(±0.002) and the anabolic reduction charge decreased from 0.46(±0.11) to 0.27(±0.02) when HMF and furfural were present. The intracellular ATP concentration was lower when inhibitors were added, but resulted only in a modest decrease in the energy charge from 0.87(±0.002) to 0.85(±0.004) compared to the control. Transcriptome profiling followed by MIPS functional enrichment analysis of up-regulated genes revealed that the functional group "Cell rescue, defense and virulence" was over-represented when inhibitors were present compared to control cultivations. Among these, the ATP-binding efflux pumps PDR5 and YOR1 were identified as important for inhibitor efflux and possibly a reason for the lower intracellular ATP concentration in stressed cells. It was also found that genes involved in pseudohyphal growth were among the most up-regulated when inhibitors were present in the feed-medium suggesting nitrogen starvation. Genes involved in amino acid metabolism, glyoxylate cycle, electron transport and amino acid transport were enriched in the down-regulated gene set in response to HMF and furfural. It was hypothesized that the HMF and furfural-induced NADPH drainage could influence ammonia assimilation and thereby give rise to the nitrogen starvation response in the form of pseudohyphal growth and down-regulation of amino acid synthesis. CONCLUSIONS The redox metabolism was severely affected by HMF and furfural while the effects on energy metabolism were less evident, suggesting that engineering of the redox system represents a possible strategy to develop more robust strains for bioethanol production.
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Affiliation(s)
- Magnus Ask
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - Maurizio Bettiga
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - Valeria Mapelli
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
| | - Lisbeth Olsson
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, SE-41296, Gothenburg, Sweden
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Koppram R, Nielsen F, Albers E, Lambert A, Wännström S, Welin L, Zacchi G, Olsson L. Simultaneous saccharification and co-fermentation for bioethanol production using corncobs at lab, PDU and demo scales. BIOTECHNOLOGY FOR BIOFUELS 2013; 6:2. [PMID: 23311728 PMCID: PMC3598390 DOI: 10.1186/1754-6834-6-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2012] [Accepted: 01/07/2013] [Indexed: 05/05/2023]
Abstract
BACKGROUND While simultaneous saccharification and co-fermentation (SSCF) is considered to be a promising process for bioconversion of lignocellulosic materials to ethanol, there are still relatively little demo-plant data and operating experiences reported in the literature. In the current work, we designed a SSCF process and scaled up from lab to demo scale reaching 4% (w/v) ethanol using xylose rich corncobs. RESULTS Seven different recombinant xylose utilizing Saccharomyces cerevisiae strains were evaluated for their fermentation performance in hydrolysates of steam pretreated corncobs. Two strains, RHD-15 and KE6-12 with highest ethanol yield and lowest xylitol yield, respectively were further screened in SSCF using the whole slurry from pretreatment. Similar ethanol yields were reached with both strains, however, KE6-12 was chosen as the preferred strain since it produced 26% lower xylitol from consumed xylose compared to RHD-15. Model SSCF experiments with glucose or hydrolysate feed in combination with prefermentation resulted in 79% of xylose consumption and more than 75% of the theoretical ethanol yield on available glucose and xylose in lab and PDU scales. The results suggest that for an efficient xylose conversion to ethanol controlled release of glucose from enzymatic hydrolysis and low levels of glucose concentration must be maintained throughout the SSCF. Fed-batch SSCF in PDU with addition of enzymes at three different time points facilitated controlled release of glucose and hence co-consumption of glucose and xylose was observed yielding 76% of the theoretical ethanol yield on available glucose and xylose at 7.9% water insoluble solids (WIS). With a fed-batch SSCF in combination with prefermentation and a feed of substrate and enzymes 47 and 40 g l-1 of ethanol corresponding to 68% and 58% of the theoretical ethanol yield on available glucose and xylose were produced at 10.5% WIS in PDU and demo scale, respectively. The strain KE6-12 was able to completely consume xylose within 76 h during the fermentation of hydrolysate in a 10 m3 demo scale bioreactor. CONCLUSIONS The potential of SSCF is improved in combination with prefermentation and a feed of substrate and enzymes. It was possible to successfully reproduce the fed-batch SSCF at demo scale producing 4% (w/v) ethanol which is the minimum economical requirement for efficient lignocellulosic bioethanol production process.
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Affiliation(s)
- Rakesh Koppram
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, Göteborg SE-412 96, Sweden
| | - Fredrik Nielsen
- Department of Chemical Engineering, Lund University, P.O. Box 124, Lund, SE-221 00, Sweden
| | - Eva Albers
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, Göteborg SE-412 96, Sweden
- Taurus Energy AB, Ideon, Ole Römers väg 12, Lund, SE-223 70, Sweden
| | - Annika Lambert
- SEKAB E-Technology AB, P.O. Box 286, Örnsköldsvik, SE-891 26, Sweden
| | - Sune Wännström
- SEKAB E-Technology AB, P.O. Box 286, Örnsköldsvik, SE-891 26, Sweden
| | - Lars Welin
- Taurus Energy AB, Ideon, Ole Römers väg 12, Lund, SE-223 70, Sweden
| | - Guido Zacchi
- Department of Chemical Engineering, Lund University, P.O. Box 124, Lund, SE-221 00, Sweden
| | - Lisbeth Olsson
- Department of Chemical and Biological Engineering, Industrial Biotechnology, Chalmers University of Technology, Göteborg SE-412 96, Sweden
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49
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Mutturi S, Lidén G. Effect of Temperature on Simultaneous Saccharification and Fermentation of Pretreated Spruce and Arundo. Ind Eng Chem Res 2013. [DOI: 10.1021/ie302851w] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sarma Mutturi
- Department of Chemical
Engineering, Lund University, P.O Box 124, 221 00, Lund, Sweden
| | - Gunnar Lidén
- Department of Chemical
Engineering, Lund University, P.O Box 124, 221 00, Lund, Sweden
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