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Tsegaye KN, Alemnew M, Berhane N. Saccharomyces cerevisiae for lignocellulosic ethanol production: a look at key attributes and genome shuffling. Front Bioeng Biotechnol 2024; 12:1466644. [PMID: 39386039 PMCID: PMC11461319 DOI: 10.3389/fbioe.2024.1466644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2024] [Accepted: 09/17/2024] [Indexed: 10/12/2024] Open
Abstract
These days, bioethanol research is looking at using non-edible plant materials, called lignocellulosic feedstocks, because they are cheap, plentiful, and renewable. However, these materials are complex and require pretreatment to release fermentable sugars. Saccharomyces cerevisiae, the industrial workhorse for bioethanol production, thrives in sugary environments and can handle high levels of ethanol. However, during lignocellulose fermentation, S. cerevisiae faces challenges like high sugar and ethanol concentrations, elevated temperatures, and even some toxic substances present in the pretreated feedstocks. Also, S. cerevisiae struggles to efficiently convert all the sugars (hexose and pentose) present in lignocellulosic hydrolysates. That's why scientists are exploring the natural variations within Saccharomyces strains and even figuring out ways to improve them. This review highlights why Saccharomyces cerevisiae remains a crucial player for large-scale bioethanol production from lignocellulose and discusses the potential of genome shuffling to create even more efficient yeast strains.
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Affiliation(s)
- Kindu Nibret Tsegaye
- Department of Biology, Gondar College of Teachers Education, Gondar, Ethiopia
- Institute of Biotechnology, University of Gondar, Gondar, Ethiopia
| | - Marew Alemnew
- Institute of Biotechnology, University of Gondar, Gondar, Ethiopia
| | - Nega Berhane
- Institute of Biotechnology, University of Gondar, Gondar, Ethiopia
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2
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Costa P, Basaglia M, Casella S, Favaro L. Copolymers as a turning point for large scale polyhydroxyalkanoates applications. Int J Biol Macromol 2024; 275:133575. [PMID: 38960239 DOI: 10.1016/j.ijbiomac.2024.133575] [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: 01/20/2024] [Revised: 05/28/2024] [Accepted: 06/28/2024] [Indexed: 07/05/2024]
Abstract
Traditional plastics reshaped the society thanks to their brilliant properties and cut-price manufacturing costs. However, their protracted durability and limited recycling threaten the environment. Worthy alternatives seem to be polyhydroxyalkanoates, compostable biopolymers produced by several microbes. The most common 3-hydroxybutyrate homopolymer has limited applications calling for copolymers biosynthesis to enhance material properties. As a growing number of researches assess the discovery of novel comonomers, great endeavors are dedicated as well to copolymers production scale-up, where the choice of the microbial carbon source significantly affects the overall economic feasibility. Diving into novel metabolic pathways, engineered strains, and cutting-edge bioprocess strategies, this review aims to survey up-to-date publications about copolymers production, focusing primarily on precursors origins. Specifically, in the core of the review, copolymers precursors have been divided into three categories based on their economic value: the costliest structurally related ones, the structurally unrelated ones, and finally various low-cost waste streams. The combination of cheap biomasses, efficient pretreatment strategies, and robust microorganisms paths the way towards the development of versatile and circular polymers. Conceived to researchers and industries interested in tackling polyhydroxyalkanoates production, this review explores an angle often underestimated yet of prime importance: if PHAs copolymers offer advanced properties and sustainable end-of-life, the feedstock choice for their upstream becomes a major factor in the development of plastic substitutes.
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Affiliation(s)
- Paolo Costa
- Waste-to-Bioproducts Lab, Department of Agronomy, Food, Natural resources, Animals and Environment (DAFNAE), University of Padova, Agripolis, Viale dell'Università, 16, 35020 Legnaro, PD, Italy.
| | - Marina Basaglia
- Waste-to-Bioproducts Lab, Department of Agronomy, Food, Natural resources, Animals and Environment (DAFNAE), University of Padova, Agripolis, Viale dell'Università, 16, 35020 Legnaro, PD, Italy.
| | - Sergio Casella
- Waste-to-Bioproducts Lab, Department of Agronomy, Food, Natural resources, Animals and Environment (DAFNAE), University of Padova, Agripolis, Viale dell'Università, 16, 35020 Legnaro, PD, Italy.
| | - Lorenzo Favaro
- Waste-to-Bioproducts Lab, Department of Agronomy, Food, Natural resources, Animals and Environment (DAFNAE), University of Padova, Agripolis, Viale dell'Università, 16, 35020 Legnaro, PD, Italy; Department of Microbiology, Stellenbosch University, Private Bag X1, 7602 Matieland, South Africa.
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3
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Deshavath NN, Woodruff W, Eller F, Susanto V, Yang C, Rao CV, Singh V. Scale-up of microbial lipid and bioethanol production from oilcane. BIORESOURCE TECHNOLOGY 2024; 399:130594. [PMID: 38493941 DOI: 10.1016/j.biortech.2024.130594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2024] [Revised: 03/14/2024] [Accepted: 03/14/2024] [Indexed: 03/19/2024]
Abstract
Microbial oils are a sustainable biomass-derived substitute for liquid fuels and vegetable oils. Oilcane, an engineered sugarcane with superior feedstock characteristics for biodiesel production, is a promising candidate for bioconversion. This study describes the processing of oilcane stems into juice and hydrothermally pretreated lignocellulosic hydrolysate and their valorization to ethanol and microbial oil using Saccharomyces cerevisiae and engineered Rhodosporidium toruloides strains, respectively. A bioethanol titer of 106 g/L was obtained from S. cerevisiae grown on oilcane juice in a 3 L fermenter, and a lipid titer of 8.8 g/L was obtained from R. toruloides grown on oilcane hydrolysate in a 75 L fermenter. Oil was extracted from the R. toruloides cells using supercritical CO2, and the observed fatty acid profile was consistent with previous studies on this strain. These results demonstrate the feasibility of pilot-scale lipid production from oilcane hydrolysate as part of an integrated bioconversion strategy.
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Affiliation(s)
- Narendra Naik Deshavath
- Department of Agricultural and Biological Engineering, University of Illinois Urbana Champaign, Urbana, IL 61801, USA; Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), Department of Energy (DOE), USA.
| | - William Woodruff
- Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), Department of Energy (DOE), USA; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Fred Eller
- United States Department of Agriculture, Agricultural Research Service, National Center for Agricultural Utilization Research, Functional Foods Research Unit, 1815 N University, Peoria, IL 61604, USA.
| | - Vionna Susanto
- Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), Department of Energy (DOE), USA; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Cindy Yang
- Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), Department of Energy (DOE), USA; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Christopher V Rao
- Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), Department of Energy (DOE), USA; Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
| | - Vijay Singh
- Department of Agricultural and Biological Engineering, University of Illinois Urbana Champaign, Urbana, IL 61801, USA; Center for Advanced Bioenergy and Bioproducts Innovation (CABBI), Department of Energy (DOE), USA.
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Long Y, Han X, Meng X, Xu P, Tao F. A robust yeast chassis: comprehensive characterization of a fast-growing Saccharomyces cerevisiae. mBio 2024; 15:e0319623. [PMID: 38214535 PMCID: PMC10865977 DOI: 10.1128/mbio.03196-23] [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: 11/30/2023] [Accepted: 12/07/2023] [Indexed: 01/13/2024] Open
Abstract
Robust chassis are critical to facilitate advances in synthetic biology. This study describes a comprehensive characterization of a new yeast isolate Saccharomyces cerevisiae XP that grows faster than commonly used research and industrial S. cerevisiae strains. The genomic, transcriptomic, and metabolomic analyses suggest that the fast growth rate is, in part, due to the efficient electron transport chain and key growth factor synthesis. A toolbox for genetic manipulation of the yeast was developed; we used it to construct l-lactic acid producers for high lactate production. The development of genetically malleable yeast strains that grow faster than currently used strains may significantly enhance the uses of S. cerevisiae in biotechnology.IMPORTANCEYeast is known as an outstanding starting strain for constructing microbial cell factories. However, its growth rate restricts its application. A yeast strain XP, which grows fast in high concentrations of sugar and acidic environments, is revealed to demonstrate the potential in industrial applications. A toolbox was also built for its genetic manipulation including gene insertion, deletion, and ploidy transformation. The knowledge of its metabolism, which could guide the designing of genetic experiments, was generated with multi-omics analyses. This novel strain along with its toolbox was then tested by constructing an l-lactic acid efficient producer, which is conducive to the development of degradable plastics. This study highlights the remarkable competence of nonconventional yeast for applications in biotechnology.
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Affiliation(s)
- Yangdanyu Long
- State Key Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xiao Han
- State Key Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Xuanlin Meng
- State Key Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism and School of Life Sciences & Biotechnology, Shanghai Jiao Tong University, Shanghai, China
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5
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Asemoloye MD, Bello TS, Oladoye PO, Remilekun Gbadamosi M, Babarinde SO, Ebenezer Adebami G, Olowe OM, Temporiti MEE, Wanek W, Marchisio MA. Engineered yeasts and lignocellulosic biomaterials: shaping a new dimension for biorefinery and global bioeconomy. Bioengineered 2023; 14:2269328. [PMID: 37850721 PMCID: PMC10586088 DOI: 10.1080/21655979.2023.2269328] [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: 06/24/2023] [Accepted: 10/03/2023] [Indexed: 10/19/2023] Open
Abstract
The next milestone of synthetic biology research relies on the development of customized microbes for specific industrial purposes. Metabolic pathways of an organism, for example, depict its chemical repertoire and its genetic makeup. If genes controlling such pathways can be identified, scientists can decide to enhance or rewrite them for different purposes depending on the organism and the desired metabolites. The lignocellulosic biorefinery has achieved good progress over the past few years with potential impact on global bioeconomy. This principle aims to produce different bio-based products like biochemical(s) or biofuel(s) from plant biomass under microbial actions. Meanwhile, yeasts have proven very useful for different biotechnological applications. Hence, their potentials in genetic/metabolic engineering can be fully explored for lignocellulosic biorefineries. For instance, the secretion of enzymes above the natural limit (aided by genetic engineering) would speed-up the down-line processes in lignocellulosic biorefineries and the cost. Thus, the next milestone would greatly require the development of synthetic yeasts with much more efficient metabolic capacities to achieve basic requirements for particular biorefinery. This review gave comprehensive overview of lignocellulosic biomaterials and their importance in bioeconomy. Many researchers have demonstrated the engineering of several ligninolytic enzymes in heterologous yeast hosts. However, there are still many factors needing to be well understood like the secretion time, titter value, thermal stability, pH tolerance, and reactivity of the recombinant enzymes. Here, we give a detailed account of the potentials of engineered yeasts being discussed, as well as the constraints associated with their development and applications.
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Affiliation(s)
- Michael Dare Asemoloye
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, Nankai District, China
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Tunde Sheriffdeen Bello
- Department of Plant Biology, School of Life Sciences, Federal University of Technology Minna, Minna Niger State, Nigeria
| | | | | | - Segun Oladiran Babarinde
- Department of Plant, Food and Environmental Sciences, Faculty of Agriculture, Dalhousie University, Truro, Nova Scotia, Canada
| | | | - Olumayowa Mary Olowe
- Food Security and Safety Focus Area, Faculty of Natural and Agricultural Sciences, North-West University, Private Mail Bag, Mmabatho, South Africa
| | | | - Wolfgang Wanek
- Department of Microbiology and Ecosystem Science, University of Vienna, Vienna, Austria
| | - Mario Andrea Marchisio
- School of Pharmaceutical Science and Technology, Tianjin University, Tianjin, Nankai District, China
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Nguyen PTT, Dinh TT, Tran-Van H. Construction of L-type lectin displaying Saccharomyces cerevisiae for Vibrio parahaemolyticus agglutination. Int Microbiol 2023:10.1007/s10123-023-00440-3. [PMID: 37889383 DOI: 10.1007/s10123-023-00440-3] [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: 06/21/2023] [Revised: 10/12/2023] [Accepted: 10/19/2023] [Indexed: 10/28/2023]
Abstract
The utilization of Aga1P anchor protein in the display system for expressing heterologous proteins on the surface of Saccharomyces cerevisiae has been shown to be an ideal approach. This system has the ability to improve the expression of target proteins beyond the cell surface, resulting in increased activity and stability of the expression system. Recent studies have demonstrated that a new L-type lectin from Litopenaeus vannamei (LvLTLC1) has been found to possess the capability of agglutinating Vibrio parahaemolyticus, a pathogen responsible for causing acute hepatopancreatic necrosis disease (AHPND) in shrimp. In this study, LvLTLC1 protein was designed to be expressed on the surface of S. cerevisiae via Aga1P anchor. The expression of LvLTLC1 protein on the surface of S. cerevisiae::pYIP-LvLTLC1-Aga1P was confirmed through the use of analytical techniques including SDS-PAGE, dot blot, and fluorescent immunoassay with LvLTC1-specific antibody. Subsequently, the newly generated yeast strain was evaluated for its ability to agglutinate V. parahaemolyticus and A. hydrophila. The obtained results indicated that S. cerevisiae expressing LvLTLC1 protein on its surface had the ability to agglutinate both AHPND-causing V. parahaemolyticus and A. hydrophila. This newly generated yeast strain could be served as a feed supplement for controlling bacteria in general and AHPND in particular.
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Affiliation(s)
- Phuong-Thao Thi Nguyen
- Department of Molecular and Environmental Biotechnology; Laboratory of Biosensors, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, Vietnam
- Laboratory of Molecular Biotechnology, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
- Faculty of Agriculture and Food Technology, Tien Giang University, My Tho, Vietnam
| | - Thuan-Thien Dinh
- Department of Molecular and Environmental Biotechnology; Laboratory of Biosensors, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, Vietnam
- Laboratory of Molecular Biotechnology, University of Science, Ho Chi Minh City, Vietnam
- Vietnam National University, Ho Chi Minh City, Vietnam
| | - Hieu Tran-Van
- Department of Molecular and Environmental Biotechnology; Laboratory of Biosensors, Faculty of Biology and Biotechnology, University of Science, Ho Chi Minh City, Vietnam.
- Laboratory of Molecular Biotechnology, University of Science, Ho Chi Minh City, Vietnam.
- Vietnam National University, Ho Chi Minh City, Vietnam.
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7
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Yatabe F, Seike T, Okahashi N, Ishii J, Matsuda F. Improvement of ethanol and 2,3-butanediol production in Saccharomyces cerevisiae by ATP wasting. Microb Cell Fact 2023; 22:204. [PMID: 37807050 PMCID: PMC10560415 DOI: 10.1186/s12934-023-02221-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 09/30/2023] [Indexed: 10/10/2023] Open
Abstract
BACKGROUND "ATP wasting" has been observed in 13C metabolic flux analyses of Saccharomyces cerevisiae, a yeast strain commonly used to produce ethanol. Some strains of S. cerevisiae, such as the sake strain Kyokai 7, consume approximately two-fold as much ATP as laboratory strains. Increased ATP consumption may be linked to the production of ethanol, which helps regenerate ATP. RESULTS This study was conducted to enhance ethanol and 2,3-butanediol (2,3-BDO) production in the S. cerevisiae strains, ethanol-producing strain BY318 and 2,3-BDO-producing strain YHI030, by expressing the fructose-1,6-bisphosphatase (FBPase) and ATP synthase (ATPase) genes to induce ATP dissipation. The introduction of a futile cycle for ATP consumption in the pathway was achieved by expressing various FBPase and ATPase genes from Escherichia coli and S. cerevisiae in the yeast strains. The production of ethanol and 2,3-BDO was evaluated using high-performance liquid chromatography and gas chromatography, and fermentation tests were performed on synthetic media under aerobic conditions in batch culture. The results showed that in the BY318-opt_ecoFBPase (expressing opt_ecoFBPase) and BY318-ATPase (expressing ATPase) strains, specific glucose consumption was increased by 30% and 42%, respectively, and the ethanol production rate was increased by 24% and 45%, respectively. In contrast, the YHI030-opt_ecoFBPase (expressing opt_ecoFBPase) and YHI030-ATPase (expressing ATPase) strains showed increased 2,3-BDO yields of 26% and 18%, respectively, and the specific production rate of 2,3-BDO was increased by 36%. Metabolomic analysis confirmed the introduction of the futile cycle. CONCLUSION ATP wasting may be an effective strategy for improving the fermentative biosynthetic capacity of S. cerevisiae, and increased ATP consumption may be a useful tool in some alcohol-producing strains.
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Affiliation(s)
- Futa Yatabe
- Department of Bioinformatics Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Taisuke Seike
- Department of Bioinformatics Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Nobuyuki Okahashi
- Department of Bioinformatics Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
- Analytical Innovation Research Laboratory, Graduate School of Engineering, Osaka University Shimadzu, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Jun Ishii
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo, 657-8501, Japan
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, Hyogo, 657-8501, Japan
| | - Fumio Matsuda
- Department of Bioinformatics Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka, 565-0871, Japan.
- Industrial Biotechnology Initiative Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
- Analytical Innovation Research Laboratory, Graduate School of Engineering, Osaka University Shimadzu, Osaka University, 2-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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Topaloğlu A, Esen Ö, Turanlı-Yıldız B, Arslan M, Çakar ZP. From Saccharomyces cerevisiae to Ethanol: Unlocking the Power of Evolutionary Engineering in Metabolic Engineering Applications. J Fungi (Basel) 2023; 9:984. [PMID: 37888240 PMCID: PMC10607480 DOI: 10.3390/jof9100984] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 09/25/2023] [Accepted: 09/28/2023] [Indexed: 10/28/2023] Open
Abstract
Increased human population and the rapid decline of fossil fuels resulted in a global tendency to look for alternative fuel sources. Environmental concerns about fossil fuel combustion led to a sharp move towards renewable and environmentally friendly biofuels. Ethanol has been the primary fossil fuel alternative due to its low carbon emission rates, high octane content and comparatively facile microbial production processes. In parallel to the increased use of bioethanol in various fields such as transportation, heating and power generation, improvements in ethanol production processes turned out to be a global hot topic. Ethanol is by far the leading yeast output amongst a broad spectrum of bio-based industries. Thus, as a well-known platform microorganism and native ethanol producer, baker's yeast Saccharomyces cerevisiae has been the primary subject of interest for both academic and industrial perspectives in terms of enhanced ethanol production processes. Metabolic engineering strategies have been primarily adopted for direct manipulation of genes of interest responsible in mainstreams of ethanol metabolism. To overcome limitations of rational metabolic engineering, an alternative bottom-up strategy called inverse metabolic engineering has been widely used. In this context, evolutionary engineering, also known as adaptive laboratory evolution (ALE), which is based on random mutagenesis and systematic selection, is a powerful strategy to improve bioethanol production of S. cerevisiae. In this review, we focus on key examples of metabolic and evolutionary engineering for improved first- and second-generation S. cerevisiae bioethanol production processes. We delve into the current state of the field and show that metabolic and evolutionary engineering strategies are intertwined and many metabolically engineered strains for bioethanol production can be further improved by powerful evolutionary engineering strategies. We also discuss potential future directions that involve recent advancements in directed genome evolution, including CRISPR-Cas9 technology.
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Affiliation(s)
- Alican Topaloğlu
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, Istanbul 34469, Türkiye; (A.T.); (Ö.E.)
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (ITU-MOBGAM), Istanbul Technical University, Istanbul 34469, Türkiye;
| | - Ömer Esen
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, Istanbul 34469, Türkiye; (A.T.); (Ö.E.)
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (ITU-MOBGAM), Istanbul Technical University, Istanbul 34469, Türkiye;
| | - Burcu Turanlı-Yıldız
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (ITU-MOBGAM), Istanbul Technical University, Istanbul 34469, Türkiye;
| | - Mevlüt Arslan
- Department of Genetics, Faculty of Veterinary Medicine, Van Yüzüncü Yıl University, Van 65000, Türkiye;
| | - Zeynep Petek Çakar
- Department of Molecular Biology and Genetics, Faculty of Science and Letters, Istanbul Technical University, Istanbul 34469, Türkiye; (A.T.); (Ö.E.)
- Dr. Orhan Öcalgiray Molecular Biology, Biotechnology and Genetics Research Center (ITU-MOBGAM), Istanbul Technical University, Istanbul 34469, Türkiye;
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Hayashi M, Ohnuki S, Tsai Y, Kondo N, Zhou Y, Zhang H, Ishii NT, Ding T, Herbig M, Isozaki A, Ohya Y, Goda K. Is AI essential? Examining the need for deep learning in image-activated sorting of Saccharomyces cerevisiae. LAB ON A CHIP 2023; 23:4232-4244. [PMID: 37650583 DOI: 10.1039/d3lc00556a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/01/2023]
Abstract
Artificial intelligence (AI) has become a focal point across a multitude of societal sectors, with science not being an exception. Particularly in the life sciences, imaging flow cytometry has increasingly integrated AI for automated management and categorization of extensive cell image data. However, the necessity of AI over traditional classification methods when extending imaging flow cytometry to include cell sorting remains uncertain, primarily due to the time constraints between image acquisition and sorting actuation. AI-enabled image-activated cell sorting (IACS) methods remain substantially limited, even as recent advancements in IACS have found success while largely relying on traditional feature gating strategies. Here we assess the necessity of AI for image classification in IACS by contrasting the performance of feature gating, classical machine learning (ML), and deep learning (DL) with convolutional neural networks (CNNs) in the differentiation of Saccharomyces cerevisiae mutant images. We show that classical ML could only yield a 2.8-fold enhancement in target enrichment capability, albeit at the cost of a 13.7-fold increase in processing time. Conversely, a CNN could offer an 11.0-fold improvement in enrichment capability at an 11.5-fold increase in processing time. We further executed IACS on mixed mutant populations and quantified target strain enrichment via downstream DNA sequencing to substantiate the applicability of DL for the proposed study. Our findings validate the feasibility and value of employing DL in IACS for morphology-based genetic screening of S. cerevisiae, encouraging its incorporation in future advancements of similar technologies.
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Affiliation(s)
- Mika Hayashi
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
| | - Shinsuke Ohnuki
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan.
| | - Yating Tsai
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan.
| | - Naoko Kondo
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan.
| | - Yuqi Zhou
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
| | - Hongqian Zhang
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
| | - Natsumi Tiffany Ishii
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
| | - Tianben Ding
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
| | - Maik Herbig
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
| | - Akihiro Isozaki
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
- Department of Mechanical Engineering, College of Science and Engineering, Ritsumeikan University, Shiga 525-8577, Japan.
| | - Yoshikazu Ohya
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, The University of Tokyo, Chiba 277-8562, Japan.
- Collaborative Research Institute for Innovative Microbiology, The University of Tokyo, Tokyo 113-8654, Japan
| | - Keisuke Goda
- Department of Chemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.
- Department of Bioengineering, University of California, Los Angeles, California 90095, USA
- Institute of Technological Sciences, Wuhan University, Wuhan 430072, China
- CYBO, Tokyo 135-0064, Japan
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10
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Liu J, Yang J, Yuan L, Wu C, Jiang Y, Zhuang W, Ying H, Yang S. Modulated Arabinose Uptake and cAMP Signaling Synergistically Improve Glucose and Arabinose Consumption in Recombinant Yeast. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:12797-12806. [PMID: 37592391 DOI: 10.1021/acs.jafc.3c04386] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/19/2023]
Abstract
During the production of ethanol from lignocellulose-derived sugars, recombinant yeasts tend to utilize xylose and arabinose after glucose exhaustion. So far, many glucose-insensitive pentose transporters have been reported to counteract this phenomenon, but few studies have described intracellular factors. In this study, the combination of adaptive evolution, comparative genomics, and genetic complementation revealed that the hexokinase-deficient (Hxk0) arabinose-fermenting Saccharomyces cerevisiae requires the arabinose transporter variant Gal2-N376T and the mutations of guanine nucleotide exchange factor Cdc25 to overcome glucose restriction during arabinose assimilation. The results showed that the Hxk0 recombinant yeasts could lower the metabolic/physiological threshold of cell proliferation by downregulating the intracellular cAMP levels, resulting in smaller cells and increased arabinose assimilation under glucose restriction. In the medium containing 80 g/L glucose and 20 g/L arabinose, the evolved strain restoring the hexokinase activity completed fermentation at 22 h, compared to 24 h for the parental strain. Overall, the experimental results provide new insights into glucose repression of biorefinery yeasts.
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Affiliation(s)
- Jinle Liu
- School of Agricultural Sciences, Zhengzhou University, Zhengzhou 450001, China
- School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Junjie Yang
- CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Lihua Yuan
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Chunhua Wu
- School of Life Sciences, Zhengzhou University, Zhengzhou 450001, China
| | - Yu Jiang
- Huzhou Center of Industrial Biotechnology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Huzhou 313000, China
| | - Wei Zhuang
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China
- School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Hanjie Ying
- College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, No. 30, Puzhu South Road, Nanjing 211816, China
- School of Chemical Engineering, Zhengzhou University, Zhengzhou 450001, China
| | - Sheng Yang
- CAS Center for Excellence in Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai 200032, China
- Huzhou Center of Industrial Biotechnology, Shanghai Institutes of Biological Sciences, Chinese Academy of Sciences, Huzhou 313000, China
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11
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Khotimah H, Astuti RI, Rafi M, Yuliana ND. Metabolomics Study Reveals Biomarker L-Proline as Potential Stress-Protectant Compound for High-Temperature Bioethanol Fermentation by Yeast Pichia kudriavzevii 1P4. Appl Biochem Biotechnol 2023; 195:5180-5198. [PMID: 37103737 DOI: 10.1007/s12010-023-04554-2] [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] [Accepted: 04/18/2023] [Indexed: 04/28/2023]
Abstract
High-temperature ethanol fermentation (> 40 °C) can be applied as effective bioprocess technology to increase ethanol production. Thermotolerant yeast Pichia kudriavzevii 1P4 showed the ability to produce ethanol at optimum 37 °C. Thus, this study evaluated the ethanol productivity of isolate 1P4 at high-temperature ethanol fermentation (42 and 45 °C) and the identification of metabolite biomarkers using untargeted metabolomics with liquid chromatography-tandem mass spectrometry (LC-MS/MS). 1P4 showed tolerance to temperature stress up to 45 °C and thus relevant for high-temperature fermentation. As measured by gas chromatography (GC), bioethanol production of 1P4 at 30, 37, 42, and 45 °C was 5.8 g/l, 7.1 g/l, 5.1 g/l, and 2.8 g/l, respectively. The classification of biomarker compounds was based on orthogonal projection analysis to latent structure discriminant analysis (OPLS-DA), resulting in L-proline being a suspected biomarker compound for isolate 1P4 tolerance against high-temperature stress. Indeed, supplementation of L-proline on fermentation medium supported the growth of 1P4 at high temperatures (> 40 °C) than without L-proline. The bioethanol production with the addition of the L-proline resulted in the highest ethanol concentration (7.15 g/l) at 42 °C. Supplementation of L-proline as a stress-protective compound increased ethanol productivity at high-temperature fermentation of 42 and 45 °C by 36.35% and 83.33%, respectively, compared without the addition of L-proline. Preliminary interpretation of these results indicates that bioprocess engineering through supplementation of stress-protective compounds L-proline increases the fermentation efficiency of isolate 1P4 at higher temperatures (42 °C and 45 °C).
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Affiliation(s)
- Husnul Khotimah
- Graduate School of Biotechnology, IPB University, Bogor, West Java, 16680, Indonesia
| | - Rika Indri Astuti
- Department of Biology, IPB University, Bogor, West Java, 16680, Indonesia.
- Biotechnology Research Center, IPB University, Bogor, West Java, Indonesia.
| | - Mohamad Rafi
- Department of Chemistry, IPB University, Bogor, West Java, 16680, Indonesia
- Advance Research Laboratory, IPB University, Bogor, West Java, 16680, Indonesia
| | - Nancy Dewi Yuliana
- Department of Food Science and Technology, IPB University, Bogor, West Java, 16680, Indonesia
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12
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Cavelius P, Engelhart-Straub S, Mehlmer N, Lercher J, Awad D, Brück T. The potential of biofuels from first to fourth generation. PLoS Biol 2023; 21:e3002063. [PMID: 36996247 PMCID: PMC10063169 DOI: 10.1371/journal.pbio.3002063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/01/2023] Open
Abstract
The steady increase in human population and a rising standard of living heighten global demand for energy. Fossil fuels account for more than three-quarters of energy production, releasing enormous amounts of carbon dioxide (CO2) that drive climate change effects as well as contributing to severe air pollution in many countries. Hence, drastic reduction of CO2 emissions, especially from fossil fuels, is essential to tackle anthropogenic climate change. To reduce CO2 emissions and to cope with the ever-growing demand for energy, it is essential to develop renewable energy sources, of which biofuels will form an important contribution. In this Essay, liquid biofuels from first to fourth generation are discussed in detail alongside their industrial development and policy implications, with a focus on the transport sector as a complementary solution to other environmentally friendly technologies, such as electric cars.
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Affiliation(s)
- Philipp Cavelius
- Werner Siemens-Chair of Synthetic Biotechnology, TUM School of Natural Sciences, Technical University of Munich (TUM), Garching, Germany
| | - Selina Engelhart-Straub
- Werner Siemens-Chair of Synthetic Biotechnology, TUM School of Natural Sciences, Technical University of Munich (TUM), Garching, Germany
| | - Norbert Mehlmer
- Werner Siemens-Chair of Synthetic Biotechnology, TUM School of Natural Sciences, Technical University of Munich (TUM), Garching, Germany
| | - Johannes Lercher
- Chair of Technical Chemistry II, TUM School of Natural Sciences, Technical University of Munich (TUM), Garching, Germany
| | - Dania Awad
- Werner Siemens-Chair of Synthetic Biotechnology, TUM School of Natural Sciences, Technical University of Munich (TUM), Garching, Germany
| | - Thomas Brück
- Werner Siemens-Chair of Synthetic Biotechnology, TUM School of Natural Sciences, Technical University of Munich (TUM), Garching, Germany
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13
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Effect of Laccase Detoxification on Bioethanol Production from Liquid Fraction of Steam-Pretreated Olive Tree Pruning. FERMENTATION-BASEL 2023. [DOI: 10.3390/fermentation9030214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
During lignocellulosic bioethanol production, the whole slurry obtained by steam explosion is filtered, generating a water-insoluble fraction rich in cellulose which is used for saccharification and ethanol fermentation, as well as a liquid fraction containing solubilised glucose and xylose but also some inhibitory by-products (furan derivatives, weak acids and phenols), which limits its use for this purpose. Since utilization of this liquid fraction to ethanol is essential for an economically feasible cellulosic ethanol process, this work studied a laccase from Myceliophthora thermophila to detoxify the liquid fraction obtained from steam-pretreated olive tree pruning (OTP) and to overcome the effects of these inhibitors. Then, the fermentation of laccase-treated liquid fraction was evaluated on ethanol production by different Saccharomyces cerevisiae strains, including the Ethanol Red, with the capacity to ferment glucose but not xylose, and the xylose-fermenting recombinant strain F12. Laccase treatment reduced total phenols content by 87% from OTP liquid fraction, not affecting furan derivatives and weak acids concentration. Consequently, the fermentative behavior of both Ethanol Red and F12 strains was improved, and ethanol production and yields were increased. Moreover, F12 strain was capable of utilizing some xylose, which increased ethanol production (10.1 g/L) compared to Ethanol Red strain (8.6 g/L).
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14
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Gupte AP, Pierantoni DC, Conti A, Donati L, Basaglia M, Casella S, Favaro L, Corte L, Cardinali G. Renewing Lost Genetic Variability with a Classical Yeast Genetics Approach. J Fungi (Basel) 2023; 9:jof9020264. [PMID: 36836378 PMCID: PMC9958831 DOI: 10.3390/jof9020264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 02/06/2023] [Accepted: 02/13/2023] [Indexed: 02/18/2023] Open
Abstract
Due to their long domestication time course, many industrial Saccharomyces cerevisiae strains are adopted in numerous processes mostly for historical reasons instead of scientific and technological needs. As such, there is still significant room for improvement for industrial yeast strains relying on yeast biodiversity. This paper strives to regenerate biodiversity with the innovative application of classic genetic methods to already available yeast strains. Extensive sporulation was indeed applied to three different yeast strains, specifically selected for their different origins as well as backgrounds, with the aim of clarifying how new variability was generated. A novel and easy method to obtain mono-spore colonies was specifically developed, and, to reveal the extent of the generated variability, no selection after sporulation was introduced. The obtained progenies were then tested for their growth in defined mediums with high stressor levels. A considerable and strain-specific increase in both phenotypic and metabolomic variability was assessed, and a few mono-spore colonies were found to be of great interest for their future exploitation in selected industrial processes.
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Affiliation(s)
- Ameya Pankaj Gupte
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
| | | | - Angela Conti
- Department of Pharmaceutical Sciences, University of Perugia, 06121 Perugia, Italy
| | - Leonardo Donati
- Department of Pharmaceutical Sciences, University of Perugia, 06121 Perugia, Italy
| | - Marina Basaglia
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
| | - Sergio Casella
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
| | - Lorenzo Favaro
- Department of Agronomy Food natural Resources Animals and Environment (DAFNAE), University of Padova, 35020 Legnaro, Italy
- Correspondence: (L.F.); (L.C.)
| | - Laura Corte
- Department of Pharmaceutical Sciences, University of Perugia, 06121 Perugia, Italy
- Correspondence: (L.F.); (L.C.)
| | - Gianluigi Cardinali
- Department of Pharmaceutical Sciences, University of Perugia, 06121 Perugia, Italy
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15
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Nawaz M, Jiang Y, Xiao Y, Yu H, Wang Z, Hu K, Zhang T, Hu J, Gao MT. Influence of Different Pretreatment Steps on the Ratio of Phenolic Compounds to Saccharides in Soluble Polysaccharides Derived from Rice Straw and Their Effect on Ethanol Fermentation. Appl Biochem Biotechnol 2023:10.1007/s12010-023-04337-9. [PMID: 36701092 DOI: 10.1007/s12010-023-04337-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/10/2023] [Indexed: 01/27/2023]
Abstract
The complex structure of rice straw is such that its bioconversion requires multiple physical and chemical pretreatment steps. In this study, it was found that a large amount of soluble polysaccharides (SPs) are formed during the pretreatment of straw. The yield of NaOH-based SPs (4.8%) was much larger than that of ball-milled SPs (1.5%) and H2SO4-based SPs (1.1%). For all the pretreatments, the ratio of phenolic compounds to saccharides (P/S) for each type of SPs increased upon increasing the concentration of ethanol in the order of 90% > 70% > 50%. The yield of NaOH-based SPs was much higher than that of acid-based and ball-milled SPs. The changes in the 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid (ABTS), ferric reducing antioxidant power assay (FRAP), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) of SPs follow the same rule, i.e., the higher the P/S ratio, the higher the antioxidant values of the SPs. The flow cytometry and laser scanning microscopy results show that the P/S ratio can significantly influence the effect of SPs on microbial growth and cell membrane permeability. Upon varying the ethanol concentration in the range of 50-90%, the P/S ratio increased from 0.02 to 0.17, resulting in an increase in the promoting effects of the SPs on yeast cell growth. Furthermore, H2O2, NAD+/NADH, and NADP+/NADPH assays indicate that SPs with a high P/S ratio can reduce intracellular H2O2 and change the intracellular redox status.
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Affiliation(s)
- Muhammad Nawaz
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Yipeng Jiang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Ying Xiao
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Hao Yu
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Zikang Wang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Kun Hu
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Tianao Zhang
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Jiajun Hu
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China
| | - Min-Tian Gao
- Shanghai Key Laboratory of Bio-Energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai, 200444, China.
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16
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Kruasuwan W, Puseenam A, Am-in S, Trakarnpaiboon S, Sornlek W, Kocharin K, Jindamorakot S, Tanapongpipat S, Bai FY, Roongsawang N. Evaluation of thermotolerant and ethanol-tolerant Saccharomyces cerevisiae as an alternative strain for bioethanol production from industrial feedstocks. 3 Biotech 2023; 13:23. [PMID: 36573155 PMCID: PMC9789288 DOI: 10.1007/s13205-022-03436-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 11/26/2022] [Indexed: 12/25/2022] Open
Abstract
Despite the fact that yeast Saccharomyces cerevisiae is by far the most commonly used in ethanol fermentation, few have been reported to be resistant to high ethanol concentrations at high temperatures. Hence, in this study, 150 S. cerevisiae strains from the Thailand Bioresource Research Center (TBRC) were screened for ethanol production based on their glucose utilization capability at high temperatures. Four strains, TBRC 12149, 12150, 12151, and 12153, exhibited the most outstanding ethanol production at high temperatures in shaking-flask culture. Among these, strain TBRC 12151 demonstrated a high ethanol tolerance of up to 12% at 40 °C. Compared to industrial and laboratory strains, TBRC 12149 displayed strong sucrose fermentation capacity whereas TBRC 12153 and 12151, respectively, showed the greatest ethanol production from molasses and cassava starch hydrolysate at high temperatures in shaking-flask conditions. In 5-L batch fermentation, similarly to both industrial strains, strain TBRC 12153 yielded an ethanol concentration of 66.5 g L-1 (58.4% theoretical yield) from molasses after 72 h at 40 °C. In contrast, strain TBRC12151 outperformed other industrial strains in cell growth and ethanol production from cassava starch hydrolysis at 40 °C with an ethanol production of 65 g L-1 (77.7% theoretical yield) after 72 h. Thus, the thermotolerant and ethanol-tolerant S. cerevisiae TBRC 12151 displayed great potential and possible uses as an alternative strain for industrial ethanol fermentation using cassava starch hydrolysate. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-022-03436-4.
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Affiliation(s)
- Worarat Kruasuwan
- Microbial Cell Factory Research Team, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, 12120 Pathum Thani Thailand
- Present Address: Siriraj Long-Read Laboratory (Si-LoL), Division of Medical Bioinformatics, Research Department, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700 Thailand
| | - Aekkachai Puseenam
- Microbial Cell Factory Research Team, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, 12120 Pathum Thani Thailand
| | - Somjit Am-in
- Microbial Diversity and Utilization Research Team, Thailand Bioresource Research Center, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, 12120 Pathum Thani Thailand
| | - Srisakul Trakarnpaiboon
- Enzyme Technology Research Team, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, 12120 Pathum Thani Thailand
| | - Warasirin Sornlek
- Enzyme Technology Research Team, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, 12120 Pathum Thani Thailand
| | - Kanokarn Kocharin
- Microbial Cell Factory Research Team, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, 12120 Pathum Thani Thailand
| | - Sasitorn Jindamorakot
- Microbial Diversity and Utilization Research Team, Thailand Bioresource Research Center, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, 12120 Pathum Thani Thailand
| | - Sutipa Tanapongpipat
- Microbial Cell Factory Research Team, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, 12120 Pathum Thani Thailand
| | - Feng-Yan Bai
- State Key Laboratory of Mycology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Niran Roongsawang
- Microbial Cell Factory Research Team, Biorefinery and Bioproduct Technology Research Group, National Center for Genetic Engineering and Biotechnology, National Science and Technology Development Agency, 113 Thailand Science Park, Khlong Nueng, Khlong Luang, 12120 Pathum Thani Thailand
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17
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Zhang Y, Ding Z, Shahadat Hossain M, Maurya R, Yang Y, Singh V, Kumar D, Salama ES, Sun X, Sindhu R, Binod P, Zhang Z, Kumar Awasthi M. Recent advances in lignocellulosic and algal biomass pretreatment and its biorefinery approaches for biochemicals and bioenergy conversion. BIORESOURCE TECHNOLOGY 2023; 367:128281. [PMID: 36370945 DOI: 10.1016/j.biortech.2022.128281] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 11/01/2022] [Accepted: 11/02/2022] [Indexed: 06/16/2023]
Abstract
As the global demand for sustainable energy increases, lignocellulosic (such as agricultural residues, forest biomass, municipal waste, and dedicated energy crops) and algal (including macroalgae and microalgae) biomass have attracted considerable attention, because of their high availability of carbohydrates. This is a potential feedstock to produce biochemical and bioenergy. Pretreatment of biomass can disrupt their complex structure, increasing conversion efficiency and product yield. Therefore, this review comprehensively discusses recent advances in different pretreatments (physical, chemical, physicochemical, and biological pretreatments) for lignocellulosic and algal biomass and their biorefining methods. Life cycle assessment (LCA) which enables the quantification of the environmental impact assessment of a biorefinery also be introduced. Biorefinery processes such as raw material acquisition, extraction, production, waste accumulation, and waste conversion are all monitored under this concept. Nevertheless, there still exist some techno-economic barriers during biorefinery and extensive research is still needed to develop cost-effective processes.
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Affiliation(s)
- Yue Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China; Department of Agricultural and Biological Engineering, University of Florida, Gainesville, FL 32611, the United States of America
| | - Zheli Ding
- Haikou Experimental Station, Chinese Academy of Tropical Agricultural Sciences (CATAS), Haikou, Hainan Province 571101, China
| | - Md Shahadat Hossain
- Department of Chemical Engineering, SUNY College of Environmental Science and Forestry, Syracuse, NY, the United States of America
| | - Rupesh Maurya
- Department of Biosciences, School of Science, Indrashil University, Rajpur, Mehsana 382715, Gujarat, India
| | - Yulu Yang
- Department of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou City, 730000, Gansu Province, China
| | - Vijai Singh
- Department of Biosciences, School of Science, Indrashil University, Rajpur, Mehsana 382715, Gujarat, India
| | - Deepak Kumar
- Department of Chemical Engineering, SUNY College of Environmental Science and Forestry, Syracuse, NY, the United States of America
| | - El-Sayed Salama
- Department of Occupational and Environmental Health, School of Public Health, Lanzhou University, Lanzhou City, 730000, Gansu Province, China
| | - Xinwei Sun
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Raveendran Sindhu
- Department of Food Technology, TKM Institute of Technology, Kollam 691505, Kerala, India
| | - Parameswaran Binod
- Microbial Processes and Technology Division, CSIR-National Institute for Interdisciplinary Science and Technology (CSIR-NIIST), Trivandrum 695 019, Kerala, India
| | - Zengqiang Zhang
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China
| | - Mukesh Kumar Awasthi
- College of Natural Resources and Environment, Northwest A&F University, Yangling, Shaanxi Province 712100, China.
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18
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Ciamponi FE, Procópio DP, Murad NF, Franco TT, Basso TO, Brandão MM. Multi-omics network model reveals key genes associated with p-coumaric acid stress response in an industrial yeast strain. Sci Rep 2022; 12:22466. [PMID: 36577778 PMCID: PMC9797568 DOI: 10.1038/s41598-022-26843-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Accepted: 12/21/2022] [Indexed: 12/30/2022] Open
Abstract
The production of ethanol from lignocellulosic sources presents increasingly difficult issues for the global biofuel scenario, leading to increased production costs of current second-generation (2G) ethanol when compared to first-generation (1G) plants. Among the setbacks encountered in industrial processes, the presence of chemical inhibitors from pre-treatment processes severely hinders the potential of yeasts in producing ethanol at peak efficiency. However, some industrial yeast strains have, either naturally or artificially, higher tolerance levels to these compounds. Such is the case of S. cerevisiae SA-1, a Brazilian fuel ethanol industrial strain that has shown high resistance to inhibitors produced by the pre-treatment of cellulosic complexes. Our study focuses on the characterization of the transcriptomic and physiological impact of an inhibitor of this type, p-coumaric acid (pCA), on this strain under chemostat cultivation via RNAseq and quantitative physiological data. It was found that strain SA-1 tend to increase ethanol yield and production rate while decreasing biomass yield when exposed to pCA, in contrast to pCA-susceptible strains, which tend to decrease their ethanol yield and fermentation efficiency when exposed to this substance. This suggests increased metabolic activity linked to mitochondrial and peroxisomal processes. The transcriptomic analysis also revealed a plethora of differentially expressed genes located in co-expressed clusters that are associated with changes in biological pathways linked to biosynthetic and energetical processes. Furthermore, it was also identified 20 genes that act as interaction hubs for these clusters, while also having association with altered pathways and changes in metabolic outputs, potentially leading to the discovery of novel targets for metabolic engineering toward a more robust industrial yeast strain.
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Affiliation(s)
- F. E. Ciamponi
- grid.411087.b0000 0001 0723 2494Center for Molecular Biology and Genetic Engineering (CBMEG), State University of Campinas (Unicamp), Av. Cândido Rondon, 400, Campinas, SP 13083-875 Brazil
| | - D. P. Procópio
- grid.11899.380000 0004 1937 0722Department of Chemical Engineering, University of São Paulo (USP), Av. Prof. Luciano Gualberto, 380, São Paulo, SP 05508-010 Brazil
| | - N. F. Murad
- grid.411087.b0000 0001 0723 2494Center for Molecular Biology and Genetic Engineering (CBMEG), State University of Campinas (Unicamp), Av. Cândido Rondon, 400, Campinas, SP 13083-875 Brazil
| | - T. T. Franco
- grid.411087.b0000 0001 0723 2494School of Chemical Engineering (FEQ), State University of Campinas (Unicamp), Av. Albert Einstein, 500, Campinas, SP 13083-852 Brazil
| | - T. O. Basso
- grid.11899.380000 0004 1937 0722Department of Chemical Engineering, University of São Paulo (USP), Av. Prof. Luciano Gualberto, 380, São Paulo, SP 05508-010 Brazil
| | - M. M. Brandão
- grid.411087.b0000 0001 0723 2494Center for Molecular Biology and Genetic Engineering (CBMEG), State University of Campinas (Unicamp), Av. Cândido Rondon, 400, Campinas, SP 13083-875 Brazil
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19
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WANG H, WANG L, FAN K, PAN G. Tetracycline natural products: discovery, biosynthesis and engineering. Chin J Nat Med 2022; 20:773-794. [DOI: 10.1016/s1875-5364(22)60224-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Indexed: 11/03/2022]
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20
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Du YH, Wang MY, Yang LH, Tong LL, Guo DS, Ji XJ. Optimization and Scale-Up of Fermentation Processes Driven by Models. Bioengineering (Basel) 2022; 9:bioengineering9090473. [PMID: 36135019 PMCID: PMC9495923 DOI: 10.3390/bioengineering9090473] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 09/05/2022] [Accepted: 09/09/2022] [Indexed: 11/16/2022] Open
Abstract
In the era of sustainable development, the use of cell factories to produce various compounds by fermentation has attracted extensive attention; however, industrial fermentation requires not only efficient production strains, but also suitable extracellular conditions and medium components, as well as scaling-up. In this regard, the use of biological models has received much attention, and this review will provide guidance for the rapid selection of biological models. This paper first introduces two mechanistic modeling methods, kinetic modeling and constraint-based modeling (CBM), and generalizes their applications in practice. Next, we review data-driven modeling based on machine learning (ML), and highlight the application scope of different learning algorithms. The combined use of ML and CBM for constructing hybrid models is further discussed. At the end, we also discuss the recent strategies for predicting bioreactor scale-up and culture behavior through a combination of biological models and computational fluid dynamics (CFD) models.
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Affiliation(s)
- Yuan-Hang Du
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China
| | - Min-Yu Wang
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
| | - Lin-Hui Yang
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China
| | - Ling-Ling Tong
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China
| | - Dong-Sheng Guo
- School of Food Science and Pharmaceutical Engineering, Nanjing Normal University, Nanjing 210023, China
- Correspondence: (D.-S.G.); (X.-J.J.)
| | - Xiao-Jun Ji
- State Key Laboratory of Materials-Oriented Chemical Engineering, College of Biotechnology and Pharmaceutical Engineering, Nanjing Tech University, Nanjing 211816, China
- Correspondence: (D.-S.G.); (X.-J.J.)
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21
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Current Ethanol Production Requirements for the Yeast Saccharomyces cerevisiae. Int J Microbiol 2022; 2022:7878830. [PMID: 35996633 PMCID: PMC9392646 DOI: 10.1155/2022/7878830] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 06/28/2022] [Accepted: 07/12/2022] [Indexed: 11/17/2022] Open
Abstract
An increase in global energy demand has caused oil prices to reach record levels in recent times. High oil prices together with concerns over CO2 emissions have resulted in renewed interest in renewable energy. Nowadays, ethanol is the principal renewable biofuel. However, the industrial need for increased productivity, wider substrate range utilization, and the production of novel compounds leads to renewed interest in further extending the use of current industrial strains by exploiting the immense, and still unknown, potential of natural yeast strains. This review seeks to answer the following questions: (a) which characteristics should S. cerevisiae have for the current production of first- and second-generation ethanol? (b) Why are alcohol-tolerance and thermo-tolerance characteristics required? (c) Which genes are related to these characteristics? (d) What are the advances that can be achieved with the isolation of new organisms from the environment?
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Chetty BJ, Inokuma K, Hasunuma T, van Zyl WH, den Haan R. Improvement of cell-tethered cellulase activity in recombinant strains of Saccharomyces cerevisiae. Appl Microbiol Biotechnol 2022; 106:6347-6361. [PMID: 35951080 DOI: 10.1007/s00253-022-12114-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/27/2022] [Accepted: 07/28/2022] [Indexed: 11/30/2022]
Abstract
Consolidated bioprocessing (CBP) remains an attractive option for the production of commodity products from pretreated lignocellulose if a process-suitable organism can be engineered. The yeast Saccharomyces cerevisiae requires engineered cellulolytic activity to enable its use in CBP production of second-generation (2G) bioethanol. A promising strategy for heterologous cellulase production in yeast entails displaying enzymes on the cell surface by means of glycosylphosphatidylinositol (GPI) anchors. While strains producing a core set of cell-adhered cellulases that enabled crystalline cellulose hydrolysis have been created, secreted levels of enzyme were insufficient for complete cellulose hydrolysis. In fact, all reported recombinant yeast CBP candidates must overcome the drawback of generally low secretion titers. Rational strain engineering can be applied to enhance the secretion phenotype. This study aimed to improve the amount of cell-adhered cellulase activities of recombinant S. cerevisiae strains expressing a core set of four cellulases, through overexpression of genes that were previously shown to enhance cellulase secretion. Results showed significant increases in cellulolytic activity for all cell-adhered cellulase enzyme types. Cell-adhered cellobiohydrolase activity was improved by up to 101%, β-glucosidase activity by up to 99%, and endoglucanase activity by up to 231%. Improved hydrolysis of crystalline cellulose of up to 186% and improved ethanol yields from this substrate of 40-50% in different strain backgrounds were also observed. In addition, improvement in resistance to fermentation stressors was noted in some strains. These strains represent a step towards more efficient organisms for use in 2G biofuel production. KEY POINTS: • Cell-surface-adhered cellulase activity was improved in strains engineered for CBP. • Levels of improvement of activity were strain and enzyme dependent. • Crystalline cellulose conversion to ethanol could be improved up to 50%.
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Affiliation(s)
- Bronwyn Jean Chetty
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa
| | - Kentaro Inokuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
| | - Tomohisa Hasunuma
- Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
- Engineering Biology Research Center, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe, 657-8501, Japan
| | | | - Riaan den Haan
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa.
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Screening novel genes by a comprehensive strategy to construct multiple stress-tolerant industrial Saccharomyces cerevisiae with prominent bioethanol production. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2022; 15:11. [PMID: 35418148 PMCID: PMC8783499 DOI: 10.1186/s13068-022-02109-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 01/09/2022] [Indexed: 12/13/2022]
Abstract
BACKGROUND Strong multiple stress-tolerance is a desirable characteristic for Saccharomyces cerevisiae when different feedstocks are used for economical industrial ethanol production. Random mutagenesis or genome shuffling has been applied for improving multiple stress-tolerance, however, these techniques are generally time-consuming and labor cost-intensive and their molecular mechanisms are unclear. Genetic engineering, as an efficient technology, is poorly applied to construct multiple stress-tolerant industrial S. cerevisiae due to lack of clear genetic targets. Therefore, constructing multiple stress-tolerant industrial S. cerevisiae is challenging. In this study, some target genes were mined by comparative transcriptomics analysis and applied for the construction of multiple stress-tolerant industrial S. cerevisiae strains with prominent bioethanol production. RESULTS Twenty-eight shared differentially expressed genes (DEGs) were identified by comparative analysis of the transcriptomes of a multiple stress-tolerant strain E-158 and its original strain KF-7 under five stress conditions (high ethanol, high temperature, high glucose, high salt, etc.). Six of the shared DEGs which may have strong relationship with multiple stresses, including functional genes (ASP3, ENA5), genes of unknown function (YOL162W, YOR012W), and transcription factors (Crz1p, Tos8p), were selected by a comprehensive strategy from multiple aspects. Through genetic editing based on the CRISPR/Case9 technology, it was demonstrated that expression regulation of each of these six DEGs improved the multiple stress-tolerance and ethanol production of strain KF-7. In particular, the overexpression of ENA5 significantly enhanced the multiple stress-tolerance of not only KF-7 but also E-158. The resulting engineered strain, E-158-ENA5, achieved higher accumulation of ethanol. The ethanol concentrations were 101.67% and 27.31% higher than those of the E-158 when YPD media and industrial feedstocks (straw, molasses, cassava) were fermented, respectively, under stress conditions. CONCLUSION Six genes that could be used as the gene targets to improve multiple stress-tolerance and ethanol production capacities of S. cerevisiae were identified for the first time. Compared to the other five DEGs, ENA5 has a more vital function in regulating the multiple stress-tolerance of S. cerevisiae. These findings provide novel insights into the efficient construction of multiple stress-tolerant industrial S. cerevisiae suitable for the fermentation of different raw materials.
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Gronchi N, De Bernardini N, Cripwell RA, Treu L, Campanaro S, Basaglia M, Foulquié-Moreno MR, Thevelein JM, Van Zyl WH, Favaro L, Casella S. Natural Saccharomyces cerevisiae Strain Reveals Peculiar Genomic Traits for Starch-to-Bioethanol Production: the Design of an Amylolytic Consolidated Bioprocessing Yeast. Front Microbiol 2022; 12:768562. [PMID: 35126325 PMCID: PMC8815085 DOI: 10.3389/fmicb.2021.768562] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 12/17/2021] [Indexed: 11/13/2022] Open
Abstract
Natural yeast with superior fermentative traits can serve as a platform for the development of recombinant strains that can be used to improve the sustainability of bioethanol production from starch. This process will benefit from a consolidated bioprocessing (CBP) approach where an engineered strain producing amylases directly converts starch into ethanol. The yeast Saccharomyces cerevisiae L20, previously selected as outperforming the benchmark yeast Ethanol Red, was here subjected to a comparative genomic investigation using a dataset of industrial S. cerevisiae strains. Along with Ethanol Red, strain L20 was then engineered for the expression of α-amylase amyA and glucoamylase glaA genes from Aspergillus tubingensis by employing two different approaches (delta integration and CRISPR/Cas9). A correlation between the number of integrated copies and the hydrolytic abilities of the recombinants was investigated. L20 demonstrated important traits for the construction of a proficient CBP yeast. Despite showing a close relatedness to commercial wine yeast and the benchmark Ethanol Red, a unique profile of gene copy number variations (CNVs) was found in L20, mainly encoding membrane transporters and secretion pathway proteins but also the fermentative metabolism. Moreover, the genome annotation disclosed seven open reading frames (ORFs) in L20 that are absent in the reference S288C genome. Genome engineering was successfully implemented for amylase production. However, with equal amylase gene copies, L20 proved its proficiency as a good enzyme secretor by exhibiting a markedly higher amylolytic activity than Ethanol Red, in compliance to the findings of the genomic exploration. The recombinant L20 dT8 exhibited the highest amylolytic activity and produced more than 4 g/L of ethanol from 2% starch in a CBP setting without the addition of supplementary enzymes. Based on the performance of this strain, an amylase/glucoamylase ratio of 1:2.5 was suggested as baseline for further improvement of the CBP ability. Overall, L20 showed important traits for the future construction of a proficient CBP yeast. As such, this work shows that natural S. cerevisiae strains can be used for the expression of foreign secreted enzymes, paving the way to strain improvement for the starch-to-bioethanol route.
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Affiliation(s)
- Nicoletta Gronchi
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padua, Legnaro, Italy
| | | | - Rosemary A Cripwell
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Laura Treu
- Department of Biology, University of Padua, Padua, Italy
| | | | - Marina Basaglia
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padua, Legnaro, Italy
| | | | - Johan M Thevelein
- Department of Molecular Microbiology, VIB, KU Leuven, Leuven, Belgium
- NovelYeast Bv, Open Bio-Incubator, Erasmus High School, Jette, Belgium
| | - Willem H Van Zyl
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Lorenzo Favaro
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padua, Legnaro, Italy
| | - Sergio Casella
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padua, Legnaro, Italy
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Dekker WJC, Jürgens H, Ortiz-Merino RA, Mooiman C, van den Berg R, Kaljouw A, Mans R, Pronk JT. OUP accepted manuscript. FEMS Yeast Res 2022; 22:6523363. [PMID: 35137036 PMCID: PMC8862043 DOI: 10.1093/femsyr/foac007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/26/2022] [Accepted: 02/03/2022] [Indexed: 11/13/2022] Open
Abstract
While thermotolerance is an attractive trait for yeasts used in industrial ethanol production, oxygen requirements of known thermotolerant species are incompatible with process requirements. Analysis of oxygen-sufficient and oxygen-limited chemostat cultures of the facultatively fermentative, thermotolerant species Ogataea parapolymorpha showed its minimum oxygen requirements to be an order of magnitude larger than those reported for the thermotolerant yeast Kluyveromyces marxianus. High oxygen requirements of O. parapolymorpha coincided with a near absence of glycerol, a key NADH/NAD+ redox-cofactor-balancing product in many other yeasts, in oxygen-limited cultures. Genome analysis indicated absence of orthologs of the Saccharomyces cerevisiae glycerol-3-phosphate-phosphatase genes GPP1 and GPP2. Co-feeding of acetoin, whose conversion to 2,3-butanediol enables reoxidation of cytosolic NADH, supported a 2.5-fold increase of the biomass concentration in oxygen-limited cultures. An O. parapolymorpha strain in which key genes involved in mitochondrial reoxidation of NADH were inactivated did produce glycerol, but transcriptome analysis did not reveal a clear candidate for a responsible phosphatase. Expression of S. cerevisiae GPD2, which encodes NAD+-dependent glycerol-3-phosphate dehydrogenase, and GPP1 supported increased glycerol production by oxygen-limited chemostat cultures of O. parapolymorpha. These results identify dependence on respiration for NADH reoxidation as a key contributor to unexpectedly high oxygen requirements of O. parapolymorpha.
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Affiliation(s)
- Wijbrand J C Dekker
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Hannes Jürgens
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Raúl A Ortiz-Merino
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Christiaan Mooiman
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Remon van den Berg
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Astrid Kaljouw
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Robert Mans
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Jack T Pronk
- Corresponding author: Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629 HZ Delft, The Netherlands. Tel: +31 15 2783214; E-mail:
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26
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Novel Propagation Strategy of Saccharomyces cerevisiae for Enhanced Xylose Metabolism during Fermentation on Softwood Hydrolysate. FERMENTATION 2021. [DOI: 10.3390/fermentation7040288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
An economically viable production of second-generation bioethanol by recombinant xylose-fermenting Saccharomyces cerevisiae requires higher xylose fermentation rates and improved glucose–xylose co-consumption. Moreover, xylose-fermenting S. cerevisiae recognises xylose as a non-fermentable rather than a fermentable carbon source, which might partly explain why xylose is not fermented into ethanol as efficiently as glucose. This study proposes propagating S. cerevisiae on non-fermentable carbon sources to enhance xylose metabolism during fermentation. When compared to yeast grown on sucrose, cells propagated on a mix of ethanol and glycerol in shake flasks showed up to 50% higher xylose utilisation rate (in a defined xylose medium) and a double maximum fermentation rate, together with an improved C5/C6 co-consumption (on an industrial softwood hydrolysate). Based on these results, an automated propagation protocol was developed, using a fed-batch approach and the respiratory quotient to guide the ethanol and glycerol-containing feed. This successfully produced 71.29 ± 0.91 g/L yeast with an average productivity of 1.03 ± 0.05 g/L/h. These empirical findings provide the basis for the design of a simple, yet effective yeast production strategy to be used in the second-generation bioethanol industry for increased fermentation efficiency.
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Cagnin L, Gronchi N, Basaglia M, Favaro L, Casella S. Selection of Superior Yeast Strains for the Fermentation of Lignocellulosic Steam-Exploded Residues. Front Microbiol 2021; 12:756032. [PMID: 34803979 PMCID: PMC8601721 DOI: 10.3389/fmicb.2021.756032] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 10/06/2021] [Indexed: 11/13/2022] Open
Abstract
The production of lignocellulosic ethanol calls for a robust fermentative yeast able to tolerate a wide range of toxic molecules that occur in the pre-treated lignocellulose. The concentration of inhibitors varies according to the composition of the lignocellulosic material and the harshness of the pre-treatment used. It follows that the versatility of the yeast should be considered when selecting a robust strain. This work aimed at the validation of seven natural Saccharomyces cerevisiae strains, previously selected for their industrial fitness, for their application in the production of lignocellulosic bioethanol. Their inhibitor resistance and fermentative performances were compared to those of the benchmark industrial yeast S. cerevisiae Ethanol Red, currently utilized in the second-generation ethanol plants. The yeast strains were characterized for their tolerance using a synthetic inhibitor mixture formulated with increasing concentrations of weak acids and furans, as well as steam-exploded lignocellulosic pre-hydrolysates, generally containing the same inhibitors. The eight non-diluted liquors have been adopted to assess yeast ability to withstand bioethanol industrial conditions. The most tolerant S. cerevisiae Fm17 strain, together with the reference Ethanol Red, was evaluated for fermentative performances in two pre-hydrolysates obtained from cardoon and common reed, chosen for their large inhibitor concentrations. S. cerevisiae Fm17 outperformed the industrial strain Ethanol Red, producing up to 18 and 39 g/L ethanol from cardoon and common reed, respectively, with ethanol yields always higher than those of the benchmark strain. This natural strain exhibits great potential to be used as superior yeast in the lignocellulosic ethanol plants.
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Affiliation(s)
- Lorenzo Cagnin
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
| | - Nicoletta Gronchi
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
| | - Marina Basaglia
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
| | - Lorenzo Favaro
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
| | - Sergio Casella
- Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Legnaro, Italy
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Rodríguez G JE, Brojanigo S, Basaglia M, Favaro L, Casella S. Efficient production of polyhydroxybutyrate from slaughterhouse waste using a recombinant strain of Cupriavidus necator DSM 545. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 794:148754. [PMID: 34225137 DOI: 10.1016/j.scitotenv.2021.148754] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Revised: 06/23/2021] [Accepted: 06/25/2021] [Indexed: 06/13/2023]
Abstract
Slaughterhouse residues are greatly available and can pose a threat to the environment if not disposed of correctly. Such by-products can be proficiently processed into polyhydroxyalkanoates by accurately selected and developed bacterial strains. Cupriavidus necator DSM 545, one of the most efficient polyhydroxyalkanoates-producing strain, cannot grow well on fatty substrates. In this work, a recombinant lipolytic C. necator microbe was developed for the efficient conversion of slaughtering by-products into polyhydroxyalkanoates. Two lipase sequences, lipC and lipH of Pseudomonas stutzeri BT3, were effectively expressed in C. necator DSM 545. The engineered strain C. necator DSM 545 JR11, selected for the outstanding extracellular lipolytic activity, produced high levels of polyhydroxyalkanoates (nearly 65% of cell dry mass) from udder, jowl and membrane caul fat. This research is crucial to the cost-effective one-step processing of slaughterhouse waste into polyhydroxyalkanoates with useful applications in several industrial and medical sectors.
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Affiliation(s)
- Jesús E Rodríguez G
- Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
| | - Silvia Brojanigo
- Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
| | - Marina Basaglia
- Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
| | - Lorenzo Favaro
- Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
| | - Sergio Casella
- Department of Agronomy Food Natural Resources Animals and Environment (DAFNAE), University of Padova, Agripolis, Viale dell'Università 16, 35020 Legnaro, PD, Italy.
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29
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State-of-the-art in analytical methods for metabolic profiling of Saccharomyces cerevisiae. Microchem J 2021. [DOI: 10.1016/j.microc.2021.106704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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den Haan R, Rose SH, Cripwell RA, Trollope KM, Myburgh MW, Viljoen-Bloom M, van Zyl WH. Heterologous production of cellulose- and starch-degrading hydrolases to expand Saccharomyces cerevisiae substrate utilization: Lessons learnt. Biotechnol Adv 2021; 53:107859. [PMID: 34678441 DOI: 10.1016/j.biotechadv.2021.107859] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Revised: 10/14/2021] [Accepted: 10/15/2021] [Indexed: 12/28/2022]
Abstract
Selected strains of Saccharomyces cerevisiae are used for commercial bioethanol production from cellulose and starch, but the high cost of exogenous enzymes for substrate hydrolysis remains a challenge. This can be addressed through consolidated bioprocessing (CBP) where S. cerevisiae strains are engineered to express recombinant glycoside hydrolases during fermentation. Looking back at numerous strategies undertaken over the past four decades to improve recombinant protein production in S. cerevisiae, it is evident that various steps in the protein production "pipeline" can be manipulated depending on the protein of interest and its anticipated application. In this review, we briefly introduce some of the strategies and highlight lessons learned with regards to improved transcription, translation, post-translational modification and protein secretion of heterologous hydrolases. We examine how host strain selection and modification, as well as enzyme compatibility, are crucial determinants for overall success. Finally, we discuss how lessons from heterologous hydrolase expression can inform modern synthetic biology and genome editing tools to provide process-ready yeast strains in future. However, it is clear that the successful expression of any particular enzyme is still unpredictable and requires a trial-and-error approach.
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Affiliation(s)
- Riaan den Haan
- Department of Biotechnology, University of the Western Cape, Bellville, South Africa
| | - Shaunita H Rose
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Rosemary A Cripwell
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Kim M Trollope
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | - Marthinus W Myburgh
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa
| | | | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Stellenbosch, South Africa.
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31
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Myburgh MW, Rose SH, Viljoen-Bloom M. Evaluating and engineering Saccharomyces cerevisiae promoters for increased amylase expression and bioethanol production from raw starch. FEMS Yeast Res 2021; 20:5891427. [PMID: 32785598 DOI: 10.1093/femsyr/foaa047] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 08/10/2020] [Indexed: 02/06/2023] Open
Abstract
Bioethanol production from starchy biomass via consolidated bioprocessing (CBP) will benefit from amylolytic Saccharomyces cerevisiae strains that produce high levels of recombinant amylases. This could be achieved by using strong promoters and modification thereof to improve gene expression under industrial conditions. This study evaluated eight endogenous S. cerevisiae promoters for the expression of a starch-hydrolysing α-amylase gene. A total of six of the native promoters were modified to contain a promoter-proximal intron directly downstream of the full-length promoter. Varying results were obtained; four native promoters outperformed the ENO1P benchmark under aerobic conditions and two promoters showed better expression under simulated CBP conditions. The addition of the RPS25A intron significantly improved the expression from most promoters, displaying increased transcript levels, protein concentrations and amylase activities. Raw starch-utilising strains were constructed through co-expression of selected α-amylase cassettes and a glucoamylase gene. The amylolytic strains displayed improved fermentation vigour on raw corn starch and broken rice, reaching 97% of the theoretical ethanol yield and converting 100% of the available carbon to products within 120 h in small-scale CBP fermentations on broken rice. This study showed that enhanced amylolytic strains for the conversion of raw starch to ethanol can be achieved through turnkey promoter selection and/or engineering.
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Affiliation(s)
- Marthinus W Myburgh
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Shaunita H Rose
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Marinda Viljoen-Bloom
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
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32
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Podolsky IA, Schauer EE, Seppälä S, O'Malley MA. Identification of novel membrane proteins for improved lignocellulose conversion. Curr Opin Biotechnol 2021; 73:198-204. [PMID: 34482155 DOI: 10.1016/j.copbio.2021.08.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 08/03/2021] [Accepted: 08/09/2021] [Indexed: 11/28/2022]
Abstract
Lignocellulose processing yields a heterogeneous mixture of substances, which are poorly utilized by current industrial strains. For efficient valorization of recalcitrant biomass, it is critical to identify and engineer new membrane proteins that enable the broad uptake of hydrolyzed substrates. Whereas glucose consumption rarely presents a bottleneck for cell factories, there is also a lack of transporters that allow co-consumption of glucose with other abundant biomass sugars such as xylose. This review discusses recent efforts to bioinformatically identify membrane proteins of high biotech potential for lignocellulose conversion and metabolic engineering in both model and nonconventional organisms. Of particular interest are transporters sourced from anaerobic gut fungi resident to large herbivores, which produce Sugars Will Eventually be Exported Transporters (SWEETs) that enhance xylose transport in the yeast Saccharomyces cerevisiae and enable glucose and xylose co-utilization. Additionally, recently identified fungal cellodextrin transporters are valuable alternatives to mitigate glucose repression and transporter inhibition.
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Affiliation(s)
- Igor A Podolsky
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Elizabeth E Schauer
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Susanna Seppälä
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA
| | - Michelle A O'Malley
- Department of Chemical Engineering, University of California Santa Barbara, Santa Barbara, CA 93106, USA; Joint BioEnergy Institute (JBEI), Emeryville, CA 94608, USA.
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Dekker WJC, Ortiz-Merino RA, Kaljouw A, Battjes J, Wiering FW, Mooiman C, Torre PDL, Pronk JT. Engineering the thermotolerant industrial yeast Kluyveromyces marxianus for anaerobic growth. Metab Eng 2021; 67:347-364. [PMID: 34303845 DOI: 10.1016/j.ymben.2021.07.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 07/06/2021] [Accepted: 07/13/2021] [Indexed: 10/20/2022]
Abstract
Current large-scale, anaerobic industrial processes for ethanol production from renewable carbohydrates predominantly rely on the mesophilic yeast Saccharomyces cerevisiae. Use of thermotolerant, facultatively fermentative yeasts such as Kluyveromyces marxianus could confer significant economic benefits. However, in contrast to S. cerevisiae, these yeasts cannot grow in the absence of oxygen. Responses of K. marxianus and S. cerevisiae to different oxygen-limitation regimes were analyzed in chemostats. Genome and transcriptome analysis, physiological responses to sterol supplementation and sterol-uptake measurements identified absence of a functional sterol-uptake mechanism as a key factor underlying the oxygen requirement of K. marxianus. Heterologous expression of a squalene-tetrahymanol cyclase enabled oxygen-independent synthesis of the sterol surrogate tetrahymanol in K. marxianus. After a brief adaptation under oxygen-limited conditions, tetrahymanol-expressing K. marxianus strains grew anaerobically on glucose at temperatures of up to 45 °C. These results open up new directions in the development of thermotolerant yeast strains for anaerobic industrial applications.
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Affiliation(s)
- Wijbrand J C Dekker
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629, HZ Delft, the Netherlands
| | - Raúl A Ortiz-Merino
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629, HZ Delft, the Netherlands
| | - Astrid Kaljouw
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629, HZ Delft, the Netherlands
| | - Julius Battjes
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629, HZ Delft, the Netherlands
| | - Frank W Wiering
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629, HZ Delft, the Netherlands
| | - Christiaan Mooiman
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629, HZ Delft, the Netherlands
| | - Pilar de la Torre
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629, HZ Delft, the Netherlands
| | - Jack T Pronk
- Department of Biotechnology, Delft University of Technology, van der Maasweg 9, 2629, HZ Delft, the Netherlands.
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Saccharomyces cerevisiae strains used industrially for bioethanol production. Essays Biochem 2021; 65:147-161. [PMID: 34156078 DOI: 10.1042/ebc20200160] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 05/25/2021] [Accepted: 05/28/2021] [Indexed: 01/21/2023]
Abstract
Fuel ethanol is produced by the yeast Saccharomyces cerevisiae mainly from corn starch in the United States and from sugarcane sucrose in Brazil, which together manufacture ∼85% of a global yearly production of 109.8 million m3 (in 2019). While in North America genetically engineered (GE) strains account for ∼80% of the ethanol produced, including strains that express amylases and are engineered to produce higher ethanol yields; in South America, mostly (>90%) non-GE strains are used in ethanol production, primarily as starters in non-aseptic fermentation systems with cell recycling. In spite of intensive research exploring lignocellulosic ethanol (or second generation ethanol), this option still accounts for <1% of global ethanol production. In this mini-review, we describe the main aspects of fuel ethanol production, emphasizing bioprocesses operating in North America and Brazil. We list and describe the main properties of several commercial yeast products (i.e., yeast strains) that are available worldwide to bioethanol producers, including GE strains with their respective genetic modifications. We also discuss recent studies that have started to shed light on the genes and traits that are important for the persistence and dominance of yeast strains in the non-aseptic process in Brazil. While Brazilian bioethanol yeast strains originated from a historical process of domestication for sugarcane fermentation, leading to a unique group with significant economic applications, in U.S.A., guided selection, breeding and genetic engineering approaches have driven the generation of new yeast products for the market.
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Factors Affecting Detoxification of Softwood Enzymatic Hydrolysates Using Sodium Dithionite. Processes (Basel) 2021. [DOI: 10.3390/pr9050887] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Conditioning of lignocellulosic hydrolysates with sulfur oxyanions, such as dithionite, is one of the most potent methods to improve the fermentability by counteracting effects of inhibitory by-products generated during hydrothermal pretreatment under acidic conditions. The effects of pH, treatment temperature, and dithionite dosage were explored in experiments with softwood hydrolysates, sodium dithionite, and Saccharomyces cerevisiae yeast. Treatments with dithionite at pH 5.5 or 8.5 gave similar results with regard to ethanol productivity and yield on initial glucose, and both were always at least ~20% higher than for treatment at pH 2.5. Experiments in the dithionite concentration range 5.0–12.5 mM and the temperature range 23–110 °C indicated that treatment at around 75 °C and using intermediate dithionite dosage was the best option (p ≤ 0.05). The investigation indicates that selection of the optimal temperature and dithionite dosage offers great benefits for the efficient fermentation of hydrolysates from lignin-rich biomass, such as softwood residues.
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Wang L, Li B, Wang SP, Xia ZY, Gou M, Tang YQ. Improving multiple stress-tolerance of a flocculating industrial Saccharomyces cerevisiae strain by random mutagenesis and hybridization. Process Biochem 2021. [DOI: 10.1016/j.procbio.2020.12.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Abstract
Bioethanol obtained from agro-food wastes could contribute to decrease the dependency on fossil resources, reduce the impact of fossil fuels on the environment, and mitigate the food versus fuel debate. This study is aimed to investigate the availability of residual inexpensive agro-food biomasses that could feed a second-generation bioethanol plant located in a specific area of North Eastern Italy. After the identification of all crops in the area, more than 40 agro-food residues were analyzed for their availability and compositions in terms of water, polysaccharides, and sugars potentially convertible into bioethanol. 574,166 Mg of residual wet lignocellulosic biomass corresponding to 297,325 Mg of dry material were found available for bioethanol conversion. The most promising substrates were wheat straw and vine shoots. Based on the chemical composition of residues, the potential attainable ethanol was determined. Theoretical potential ethanol production was estimated at nearly 72,000 Mg per year. This quantity extensively exceeds the minimum yearly capacity of a sustainable bioethanol plant previously identified as around 50,000 Mg of ethanol. Taken together, these results demonstrate that, in the analyzed area, agro-food residues are available in an amount that could sustain bioethanol production in a specific and restricted district. Techno-economical evaluations are in progress to assess the actual feasibility of installing a second generation bioethanol production plant in the area of interest.
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Kim IS, Choi W, Son J, Lee JH, Lee H, Lee J, Shin SC, Kim HW. Screening and Genetic Network Analysis of Genes Involved in Freezing and Thawing Resistance in DaMDHAR-Expressing Saccharomyces cerevisiae Using Gene Expression Profiling. Genes (Basel) 2021; 12:genes12020219. [PMID: 33546197 PMCID: PMC7913288 DOI: 10.3390/genes12020219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/28/2021] [Accepted: 01/30/2021] [Indexed: 01/24/2023] Open
Abstract
The cryoprotection of cell activity is a key determinant in frozen-dough technology. Although several factors that contribute to freezing tolerance have been reported, the mechanism underlying the manner in which yeast cells respond to freezing and thawing (FT) stress is not well established. Therefore, the present study demonstrated the relationship between DaMDHAR encoding monodehydroascorbate reductase from Antarctic hairgrass Deschampsia antarctica and stress tolerance to repeated FT cycles (FT2) in transgenic yeast Saccharomyces cerevisiae. DaMDHAR-expressing yeast (DM) cells identified by immunoblotting analysis showed high tolerance to FT stress conditions, thereby causing lower damage for yeast cells than wild-type (WT) cells with empty vector alone. To detect FT2 tolerance-associated genes, 3′-quant RNA sequencing was employed using mRNA isolated from DM and WT cells exposed to FT (FT2) conditions. Approximately 332 genes showed ≥2-fold changes in DM cells and were classified into various groups according to their gene expression. The expressions of the changed genes were further confirmed using western blot analysis and biochemical assay. The upregulated expression of 197 genes was associated with pentose phosphate pathway, NADP metabolic process, metal ion homeostasis, sulfate assimilation, β-alanine metabolism, glycerol synthesis, and integral component of mitochondrial and plasma membrane (PM) in DM cells under FT2 stress, whereas the expression of the remaining 135 genes was partially related to protein processing, selenocompound metabolism, cell cycle arrest, oxidative phosphorylation, and α-glucoside transport under the same condition. With regard to transcription factors in DM cells, MSN4 and CIN5 were activated, but MSN2 and MGA1 were not. Regarding antioxidant systems and protein kinases in DM cells under FT stress, CTT1, GTO, GEX1, and YOL024W were upregulated, whereas AIF1, COX2, and TRX3 were not. Gene activation represented by transcription factors and enzymatic antioxidants appears to be associated with FT2-stress tolerance in transgenic yeast cells. RCK1, MET14, and SIP18, but not YPK2, have been known to be involved in the protein kinase-mediated signalling pathway and glycogen synthesis. Moreover, SPI18 and HSP12 encoding hydrophilin in the PM were detected. Therefore, it was concluded that the genetic network via the change of gene expression levels of multiple genes contributing to the stabilization and functionality of the mitochondria and PM, not of a single gene, might be the crucial determinant for FT tolerance in DaMDAHR-expressing transgenic yeast. These findings provide a foundation for elucidating the DaMDHAR-dependent molecular mechanism of the complex functional resistance in the cellular response to FT stress.
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Affiliation(s)
- Il-Sup Kim
- Advanced Bio-Resource Research Center, Kyungpook National University, Daegu 41566, Korea;
| | - Woong Choi
- Korea Polar Research Institute, Incheon 21990, Korea; (W.C.); (J.S.); (J.H.L.); (H.L.); (J.L.); (S.C.S.)
| | - Jonghyeon Son
- Korea Polar Research Institute, Incheon 21990, Korea; (W.C.); (J.S.); (J.H.L.); (H.L.); (J.L.); (S.C.S.)
| | - Jun Hyuck Lee
- Korea Polar Research Institute, Incheon 21990, Korea; (W.C.); (J.S.); (J.H.L.); (H.L.); (J.L.); (S.C.S.)
- Department of Polar Science, University of Science and Technology, Incheon 21990, Korea
| | - Hyoungseok Lee
- Korea Polar Research Institute, Incheon 21990, Korea; (W.C.); (J.S.); (J.H.L.); (H.L.); (J.L.); (S.C.S.)
- Department of Polar Science, University of Science and Technology, Incheon 21990, Korea
| | - Jungeun Lee
- Korea Polar Research Institute, Incheon 21990, Korea; (W.C.); (J.S.); (J.H.L.); (H.L.); (J.L.); (S.C.S.)
- Department of Polar Science, University of Science and Technology, Incheon 21990, Korea
| | - Seung Chul Shin
- Korea Polar Research Institute, Incheon 21990, Korea; (W.C.); (J.S.); (J.H.L.); (H.L.); (J.L.); (S.C.S.)
| | - Han-Woo Kim
- Korea Polar Research Institute, Incheon 21990, Korea; (W.C.); (J.S.); (J.H.L.); (H.L.); (J.L.); (S.C.S.)
- Department of Polar Science, University of Science and Technology, Incheon 21990, Korea
- Correspondence:
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Ilanidis D, Wu G, Stagge S, Martín C, Jönsson LJ. Effects of redox environment on hydrothermal pretreatment of lignocellulosic biomass under acidic conditions. BIORESOURCE TECHNOLOGY 2021; 319:124211. [PMID: 33045548 DOI: 10.1016/j.biortech.2020.124211] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/28/2020] [Accepted: 09/29/2020] [Indexed: 05/23/2023]
Abstract
The effects of the redox environment on acidic hydrothermal pretreatment were investigated in experiments with sugarcane bagasse (190 °C, 14 min) and Norway spruce (205 °C, 5 min). To modulate the redox environment, pretreatment was performed without gas addition, with N2, or with O2. Analyses covered pretreated solids, pretreatment liquids, condensates, enzymatic digestibility, and inhibitory effects of pretreatment liquids on yeast. Addition of gas, especially O2, resulted in increased severity, as reflected by up to 18 percent units lower recoveries of pretreated solids, up to 31 percent units lower glucan recoveries, improved hemicellulose removal, formation of pseudo-lignin, improved overall glucan conversion, and increased concentrations of several microbial inhibitors. Some inhibitors, such as formaldehyde and coniferyl aldehyde, did not, however, follow that pattern. TAC (Total Aromatic Content) values reflected inhibitory effects of pretreatment liquids. This study demonstrates how gas addition can be used to modulate the severity of acidic hydrothermal pretreatment.
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Affiliation(s)
| | - Guochao Wu
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Stefan Stagge
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Carlos Martín
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden
| | - Leif J Jönsson
- Department of Chemistry, Umeå University, SE-901 87 Umeå, Sweden.
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40
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Kim J, Hoang Nguyen Tran P, Lee SM. Current Challenges and Opportunities in Non-native Chemical Production by Engineered Yeasts. Front Bioeng Biotechnol 2021; 8:594061. [PMID: 33381497 PMCID: PMC7767886 DOI: 10.3389/fbioe.2020.594061] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 11/24/2020] [Indexed: 11/13/2022] Open
Abstract
Yeasts are promising industrial hosts for sustainable production of fuels and chemicals. Apart from efficient bioethanol production, yeasts have recently demonstrated their potential for biodiesel production from renewable resources. The fuel-oriented product profiles of yeasts are now expanding to include non-native chemicals with the advances in synthetic biology. In this review, current challenges and opportunities in yeast engineering for sustainable production of non-native chemicals will be discussed, with a focus on the comparative evaluation of a bioethanol-producing Saccharomyces cerevisiae strain and a biodiesel-producing Yarrowia lipolytica strain. Synthetic pathways diverging from the distinctive cellular metabolism of these yeasts guide future directions for product-specific engineering strategies for the sustainable production of non-native chemicals on an industrial scale.
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Affiliation(s)
- Jiwon Kim
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, South Korea.,Department of Biotechnology, Korea University, Seoul, South Korea
| | - Phuong Hoang Nguyen Tran
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, South Korea.,Division of Energy and Environment Technology, University of Science and Technology (UST), Daejeon, South Korea
| | - Sun-Mi Lee
- Clean Energy Research Center, Korea Institute of Science and Technology (KIST), Seoul, South Korea.,Division of Energy and Environment Technology, University of Science and Technology (UST), Daejeon, South Korea.,Green School, Korea University, Seoul, South Korea
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41
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Ceccato-Antonini SR, Covre EA. From baker's yeast to genetically modified budding yeasts: the scientific evolution of bioethanol industry from sugarcane. FEMS Yeast Res 2020; 20:6021367. [PMID: 33406233 DOI: 10.1093/femsyr/foaa065] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 12/02/2020] [Indexed: 12/22/2022] Open
Abstract
The peculiarities of Brazilian fuel ethanol fermentation allow the entry of native yeasts that may dominate over the starter strains of Saccharomyces cerevisiae and persist throughout the sugarcane harvest. The switch from the use of baker's yeast as starter to selected budding yeasts obtained by a selective pressure strategy was followed by a wealth of genomic information that enabled the understanding of the superiority of selected yeast strains. This review describes how the process of yeast selection evolved in the sugarcane-based bioethanol industry, the selection criteria and recent advances in genomics that could advance the fermentation process. The prospective use of genetically modified yeast strains, specially designed for increased robustness and product yield, with special emphasis on those obtained by the CRISPR (clustered regularly interspaced palindromic repeats)-Cas9 (CRISPR-associated protein 9) genome-editing approach, is discussed as a possible solution to confer higher performance and stability to the fermentation process for fuel ethanol production.
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Affiliation(s)
- Sandra Regina Ceccato-Antonini
- Laboratory of Agricultural and Molecular Microbiology, Dept Tecnologia Agroindustrial e Socioeconomia Rural, Centro de Ciências Agrárias, Universidade Federal de São Carlos, Via Anhanguera, km 174, 13600-970 Araras, São Paulo State, Brazil
| | - Elizabete Aparecida Covre
- Laboratory of Agricultural and Molecular Microbiology, Dept Tecnologia Agroindustrial e Socioeconomia Rural, Centro de Ciências Agrárias, Universidade Federal de São Carlos, Via Anhanguera, km 174, 13600-970 Araras, São Paulo State, Brazil
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42
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Zahoor A, Messerschmidt K, Boecker S, Klamt S. ATPase-based implementation of enforced ATP wasting in Saccharomyces cerevisiae for improved ethanol production. BIOTECHNOLOGY FOR BIOFUELS 2020; 13:185. [PMID: 33292464 PMCID: PMC7654063 DOI: 10.1186/s13068-020-01822-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Accepted: 10/23/2020] [Indexed: 05/06/2023]
Abstract
BACKGROUND Enforced ATP wasting has been recognized as a promising metabolic engineering strategy to enhance the microbial production of metabolites that are coupled to ATP generation. It also appears to be a suitable approach to improve production of ethanol by Saccharomyces cerevisiae. In the present study, we constructed different S. cerevisiae strains with heterologous expression of genes of the ATP-hydrolyzing F1-part of the ATPase enzyme to induce enforced ATP wasting and quantify the resulting effect on biomass and ethanol formation. RESULTS In contrast to genomic integration, we found that episomal expression of the αβγ subunits of the F1-ATPase genes of Escherichia coli in S. cerevisiae resulted in significantly increased ATPase activity, while neither genomic integration nor episomal expression of the β subunit from Trichoderma reesei could enhance ATPase activity. When grown in minimal medium under anaerobic growth-coupled conditions, the strains expressing E. coli's F1-ATPase genes showed significantly improved ethanol yield (increase of 10% compared to the control strain). However, elevated product formation reduces biomass formation and, therefore, volumetric productivity. We demonstrate that this negative effect can be overcome under growth-decoupled (nitrogen-starved) operation with high and constant biomass concentration. Under these conditions, which mimic the second (production) phase of a two-stage fermentation process, the ATPase-expressing strains showed significant improvement in volumetric productivity (up to 111%) compared to the control strain. CONCLUSIONS Our study shows that expression of genes of the F1-portion of E. coli's ATPase induces ATPase activity in S. cerevisiae and can be a promising way to improve ethanol production. This ATP-wasting strategy can be easily applied to other metabolites of interest, whose formation is coupled to ATP generation.
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Affiliation(s)
- Ahmed Zahoor
- Analysis and Redesign of Biological Networks, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany
| | - Katrin Messerschmidt
- Analysis and Redesign of Biological Networks, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany
| | - Simon Boecker
- Analysis and Redesign of Biological Networks, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany
| | - Steffen Klamt
- Analysis and Redesign of Biological Networks, Max Planck Institute for Dynamics of Complex Technical Systems, Magdeburg, Germany.
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Lopes AMM, Félix de Mélo AH, Procópio DP, Teixeira GS, Carazzolle MF, de Carvalho LM, Adelantado N, Pereira GA, Ferrer P, Filho FM, Goldbeck R. Genome sequence of Acremonium strictum AAJ6 strain isolated from the Cerrado biome in Brazil and CAZymes expression in thermotolerant industrial yeast for ethanol production. Process Biochem 2020. [DOI: 10.1016/j.procbio.2020.07.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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44
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Next Generation Winemakers: Genetic Engineering in Saccharomyces cerevisiae for Trendy Challenges. Bioengineering (Basel) 2020; 7:bioengineering7040128. [PMID: 33066502 PMCID: PMC7712467 DOI: 10.3390/bioengineering7040128] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2020] [Revised: 10/08/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023] Open
Abstract
The most famous yeast of all, Saccharomyces cerevisiae, has been used by humankind for at least 8000 years, to produce bread, beer and wine, even without knowing about its existence. Only in the last century we have been fully aware of the amazing power of this yeast not only for ancient uses but also for biotechnology purposes. In the last decades, wine culture has become and more demanding all over the world. By applying as powerful a biotechnological tool as genetic engineering in S. cerevisiae, new horizons appear to develop fresh, improved, or modified wine characteristics, properties, flavors, fragrances or production processes, to fulfill an increasingly sophisticated market that moves around 31.4 billion € per year.
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Mao Y, Chen Z, Lu L, Jin B, Ma H, Pan Y, Chen T. Efficient solid-state fermentation for the production of 5-aminolevulinic acid enriched feed using recombinant Saccharomyces cerevisiae. J Biotechnol 2020; 322:29-32. [PMID: 32653638 DOI: 10.1016/j.jbiotec.2020.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 05/24/2020] [Accepted: 06/04/2020] [Indexed: 11/17/2022]
Abstract
Over the past decade, 5-aminolevulinic acid (5-ALA) has been highlighted as a promising functional feed additive and immunomodulator for improving the general health, immune response, and resistance to disease of livestock and poultry. However, it is very costly to produce 5-ALA using conventional chemical synthesis methods. Classical microbial fermentation fulfills the criteria of environmental friendliness, but the unsatisfactory titers still hinder actual industrial production. This study aimed to develop a solid-state fermentation (SSF) process that can be used to efficiently enrich feed with 5-ALA at a low cost. First, the endogenous 5-ALA synthase was overexpressed in Saccharomyces cerevisiae via integrating a copy of HEM1 gene into the chromosome and introducing a multi-copy plasmid pRS416-HEM1 which constitutively overexpresses HEM1 gene. The resulting strain ScA3 was able to produce 63.82 mg/L 5-ALA in shake-flask fermentation. After process optimization, a titer of 225.63 mg/kg dry materials, exceeding the usual effective dosage reported in animal trials, was achieved within 48 h through SSF of 20 kg feed in a 90-L steel drum. To our knowledge, this is the first report on combining microbial 5-ALA production with SSF in feed processing, which will hopefully promote the application and popularization of 5-ALA in the feed industry.
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Affiliation(s)
- Yufeng Mao
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China; Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of Ministry of Education, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Zetian Chen
- Henan Yihongshancheng Bio-Tech Co. Ltd., Yihongshancheng Park, South Gongye Road, Wuzhi, Henan 454950, China
| | - Lingxue Lu
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of Ministry of Education, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Biao Jin
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of Ministry of Education, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China
| | - Hongwu Ma
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Yun Pan
- Henan Yihongshancheng Bio-Tech Co. Ltd., Yihongshancheng Park, South Gongye Road, Wuzhi, Henan 454950, China.
| | - Tao Chen
- Frontier Science Center for Synthetic Biology and Key Laboratory of Systems Bioengineering of Ministry of Education, SynBio Research Platform, Collaborative Innovation Center of Chemical Science and Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
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Pinheiro ÁDT, Barros EM, Rocha LA, Ponte VMDR, de Macedo AC, Rocha MVP, Gonçalves LRB. Optimization and scale-up of ethanol production by a flocculent yeast using cashew apple juice as feedstock. BRAZILIAN JOURNAL OF CHEMICAL ENGINEERING 2020. [DOI: 10.1007/s43153-020-00068-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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48
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Brojanigo S, Parro E, Cazzorla T, Favaro L, Basaglia M, Casella S. Conversion of Starchy Waste Streams into Polyhydroxyalkanoates Using Cupriavidus necator DSM 545. Polymers (Basel) 2020; 12:polym12071496. [PMID: 32635554 PMCID: PMC7407217 DOI: 10.3390/polym12071496] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 06/26/2020] [Accepted: 06/30/2020] [Indexed: 01/23/2023] Open
Abstract
Due to oil shortage and environmental problems, synthetic plastics have to be replaced by different biodegradable materials. A promising alternative could be polyhydroxyalkanoates (PHAs), and the low-cost abundant agricultural starchy by-products could be usefully converted into PHAs by properly selected and/or developed microbes. Among the widely available starchy waste streams, a variety of residues have been explored as substrates, such as broken, discolored, unripe rice and white or purple sweet potato waste. Cupriavidus necator DSM 545, a well-known producer of PHAs, was adopted in a simultaneous saccharification and fermentation (SSF) process through an optimized dosage of the commercial amylases cocktail STARGEN™ 002. Broken rice was found to be the most promising carbon source with PHAs levels of up to 5.18 g/L. This research demonstrates that rice and sweet potato waste are low-cost feedstocks for PHAs production, paving the way for the processing of other starchy materials into bioplastics.
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Cripwell RA, Favaro L, Viljoen-Bloom M, van Zyl WH. Consolidated bioprocessing of raw starch to ethanol by Saccharomyces cerevisiae: Achievements and challenges. Biotechnol Adv 2020; 42:107579. [PMID: 32593775 DOI: 10.1016/j.biotechadv.2020.107579] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Revised: 06/05/2020] [Accepted: 06/14/2020] [Indexed: 12/30/2022]
Abstract
Recent advances in amylolytic strain engineering for starch-to-ethanol conversion have provided a platform for the development of raw starch consolidated bioprocessing (CBP) technologies. Several proof-of-concept studies identified improved enzyme combinations, alternative feedstocks and novel host strains for evaluation and application under fermentation conditions. However, further research efforts are required before this technology can be scaled up to an industrial level. In this review, different CBP approaches are defined and discussed, also highlighting the role of auxiliary enzymes for a supplemented CBP process. Various achievements in the development of amylolytic Saccharomyces cerevisiae strains for CBP of raw starch and the remaining challenges that need to be tackled/pursued to bring yeast raw starch CBP to industrial realization, are described. Looking towards the future, it provides potential solutions to develop more cost-effective processes that include cheaper substrates, integration of the 1G and 2G economies and implementing a biorefinery concept where high-value products are also derived from starchy substrates.
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Affiliation(s)
- Rosemary A Cripwell
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Lorenzo Favaro
- Department of Agronomy Food Natural resources Animals and Environment (DAFNAE), Università di Padova, Agripolis, Viale dell'Università 16, 35020, Legnaro, Padova, Italy
| | - Marinda Viljoen-Bloom
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa
| | - Willem H van Zyl
- Department of Microbiology, Stellenbosch University, Private Bag X1, Matieland 7602, South Africa.
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50
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Wang YZ, Yang J, Wei H, Hou R, Shi J, Jin Z, Yang F, Hu J, Gao MT. Reduction of Fermentation-Associated Stresses by Straw-Based Soluble Saccharides for Enhancing Ethanol Production. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:5863-5872. [PMID: 32375483 DOI: 10.1021/acs.jafc.0c00883] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
In this study, the effect of soluble polysaccharides (SPs) derived from agricultural waste, rice straw, on fermentation-associated stresses (temperature and concentrations of glucose and ethanol) was investigated to achieve high-performance ethanol production. The increase in temperature and concentrations of glucose and ethanol significantly inhibited Saccharomyces cerevisiae growth and lowered ethanol fermentation efficiency. Flow cytometric assays indicated that SPs could alleviate membrane permeability damage caused by fermentation-associated stresses. Atomic force microscopy and transmission electron microscopy revealed that fermentation-associated stresses induced cell surface shrinkage, causing a decrease in the cell size, whereas SPs stimulated the formation of extracellular matrices (EMs), which made the cell surface smooth and the cell morphology regular. Cells with EMs induced by SPs could efficiently produce ethanol under severe stresses. As a result, the titer of ethanol in the fermentation with SPs was 1.40-fold (from 26.40 to 36.98 g/L) higher than that in the fermentation without SPs, suggesting the stress-alleviating effect of SPs on ethanol production.
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Affiliation(s)
- Ya Zhu Wang
- Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Ji Yang
- Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Huanran Wei
- Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Rongrong Hou
- Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Jie Shi
- Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Zheng Jin
- Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Fan Yang
- Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Jiajun Hu
- Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
| | - Min-Tian Gao
- Shanghai Key Laboratory of Bio-energy Crops, School of Life Sciences, Shanghai University, 99 Shangda Road, Shanghai 200444, China
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