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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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Co-production of levan with other high-value bioproducts: A review. Int J Biol Macromol 2023; 235:123800. [PMID: 36828085 DOI: 10.1016/j.ijbiomac.2023.123800] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/18/2023] [Accepted: 02/18/2023] [Indexed: 02/24/2023]
Abstract
Levan is a homopolysaccharide of fructose that has both scientific and industrial importance, with various applications in health, pharmaceutical, cosmetic and food industries. Despite its broad spectrum of uses, there are only a limited number of commercial levan sources due to the high costs related to its production. To make production economically viable, efforts have been concentrated on the selection of levan-producing microorganisms, the genetic manipulation of new strains, and the use of inexpensive agro-industrial byproducts as substrates. Another efficient strategy involves the concomitant synthesis of other products with high market value and as such, the successful co-production of levan was demonstrated with fructooligosaccharides, ethanol, sorbitol, poly-ε-lysine, poly-γ-glutamic acid and polyhydroxyalkanoates. This paper offers a systematic review of important aspects regarding recent strategies involving the simultaneous synthesis of levan and other bioproducts of aggregate value reported to date and discusses the challenges and opportunities for its large-scale production and applications.
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Chen X, Wang Y, Zhang XT, Wu YN, Zhang XL, Zhang GC, Wang CL, Zou X, Wang DH, Wei GY. MAL31, a sugar transporter involved in pullulan biosynthesis in Aureobasidium pullulans. J Biotechnol 2022; 359:176-184. [DOI: 10.1016/j.jbiotec.2022.10.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Revised: 08/23/2022] [Accepted: 10/08/2022] [Indexed: 10/31/2022]
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Increasing Ethanol Tolerance and Ethanol Production in an Industrial Fuel Ethanol Saccharomyces cerevisiae Strain. FERMENTATION-BASEL 2022. [DOI: 10.3390/fermentation8100470] [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]
Abstract
The stress imposed by ethanol to Saccharomyces cerevisiae cells are one of the most challenging limiting factors in industrial fuel ethanol production. Consequently, the toxicity and tolerance to high ethanol concentrations has been the subject of extensive research, allowing the identification of several genes important for increasing the tolerance to this stress factor. However, most studies were performed with well-characterized laboratory strains, and how the results obtained with these strains work in industrial strains remains unknown. In the present work, we have tested three different strategies known to increase ethanol tolerance by laboratory strains in an industrial fuel–ethanol producing strain: the overexpression of the TRP1 or MSN2 genes, or the overexpression of a truncated version of the MSN2 gene. Our results show that the industrial CAT-1 strain tolerates up to 14% ethanol, and indeed the three strategies increased its tolerance to ethanol. When these strains were subjected to fermentations with high sugar content and cell recycle, simulating the industrial conditions used in Brazilian distilleries, only the strain with overexpression of the truncated MSN2 gene showed improved fermentation performance, allowing the production of 16% ethanol from 33% of total reducing sugars present in sugarcane molasses. Our results highlight the importance of testing genetic modifications in industrial yeast strains under industrial conditions in order to improve the production of industrial fuel ethanol by S. cerevisiae.
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Secches TO, Santos Viera CF, Pereira TKE, Santos VTO, Ribeirodos Santos J, Pereira GAG, Carazzolle MF. Brazilian industrial yeasts show high fermentative performance in high solids content for corn ethanol process. BIORESOUR BIOPROCESS 2022; 9:97. [PMID: 38647773 PMCID: PMC10991476 DOI: 10.1186/s40643-022-00580-w] [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: 04/24/2022] [Accepted: 08/12/2022] [Indexed: 11/10/2022] Open
Abstract
An imminent change in the world energy matrix makes it necessary to increase the production of renewable fuels. The United States and Brazil are the world's largest producers, but their production methods are very different, using different raw materials, ground corn and sugarcane juice, respectively. In recent years, strong investments have been made to expand the use of corn in Brazilian ethanol production. The combination of the sugar cane and corn ethanol industries has generated innovations in the sector, such as the "flex" mills, which are traditional sugar cane mills adapted to produce corn ethanol in the sugar cane off-season. Brazil has a portfolio of robust industrial yeasts for sugarcane ethanol production, naturally evolved and selected over the past 50 years. In this work, we analyze for the first time the performance of Brazilian industrial strains (BG-1, CAT-1, PE-2 and SA-1, widely used in sugarcane ethanol production) in corn ethanol production using different stress conditions. Ethanol Red yeast, traditionally used in corn ethanol plants around the world, was used as a control. In terms of tolerance to temperature (35 °C), strains BG-1 and SA-1 stood out. In fermentations with high solids concentration (35%), strain BG-1 reached ethanol contents higher than 19% w/v and had a productivity gain of 5.8% compared to fermentation at 30%. This was the first time that these industrial strains were evaluated using the high solids concentration of 35% and the results point to ways to improve the corn ethanol production process.
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Affiliation(s)
- Thaís O Secches
- Interinstitutional Graduate Program in Bioenergy (USP/UNICAMP/UNESP), Cidade Universitária, 330 Cora Coralina Street, Campinas, SP, CEP 13.083-896, Brazil
| | - Carla F Santos Viera
- Genomics and bioEnergy Laboratory (LGE), Institute of Biology, UNICAMP, Campinas, SP, Brazil
| | - Thaynara K E Pereira
- Interinstitutional Graduate Program in Bioenergy (USP/UNICAMP/UNESP), Cidade Universitária, 330 Cora Coralina Street, Campinas, SP, CEP 13.083-896, Brazil
| | - Victor T O Santos
- Genomics and bioEnergy Laboratory (LGE), Institute of Biology, UNICAMP, Campinas, SP, Brazil
| | - Jade Ribeirodos Santos
- Interinstitutional Graduate Program in Bioenergy (USP/UNICAMP/UNESP), Cidade Universitária, 330 Cora Coralina Street, Campinas, SP, CEP 13.083-896, Brazil
| | - Gonçalo A G Pereira
- Interinstitutional Graduate Program in Bioenergy (USP/UNICAMP/UNESP), Cidade Universitária, 330 Cora Coralina Street, Campinas, SP, CEP 13.083-896, Brazil.
| | - Marcelo F Carazzolle
- Interinstitutional Graduate Program in Bioenergy (USP/UNICAMP/UNESP), Cidade Universitária, 330 Cora Coralina Street, Campinas, SP, CEP 13.083-896, Brazil
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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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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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Jacobus AP, Stephens TG, Youssef P, González-Pech R, Ciccotosto-Camp MM, Dougan KE, Chen Y, Basso LC, Frazzon J, Chan CX, Gross J. Comparative Genomics Supports That Brazilian Bioethanol Saccharomyces cerevisiae Comprise a Unified Group of Domesticated Strains Related to Cachaça Spirit Yeasts. Front Microbiol 2021; 12:644089. [PMID: 33936002 PMCID: PMC8082247 DOI: 10.3389/fmicb.2021.644089] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2020] [Accepted: 03/08/2021] [Indexed: 01/05/2023] Open
Abstract
Ethanol production from sugarcane is a key renewable fuel industry in Brazil. Major drivers of this alcoholic fermentation are Saccharomyces cerevisiae strains that originally were contaminants to the system and yet prevail in the industrial process. Here we present newly sequenced genomes (using Illumina short-read and PacBio long-read data) of two monosporic isolates (H3 and H4) of the S. cerevisiae PE-2, a predominant bioethanol strain in Brazil. The assembled genomes of H3 and H4, together with 42 draft genomes of sugarcane-fermenting (fuel ethanol plus cachaça) strains, were compared against those of the reference S288C and diverse S. cerevisiae. All genomes of bioethanol yeasts have amplified SNO2(3)/SNZ2(3) gene clusters for vitamin B1/B6 biosynthesis, and display ubiquitous presence of a particular family of SAM-dependent methyl transferases, rare in S. cerevisiae. Widespread amplifications of quinone oxidoreductases YCR102C/YLR460C/YNL134C, and the structural or punctual variations among aquaporins and components of the iron homeostasis system, likely represent adaptations to industrial fermentation. Interesting is the pervasive presence among the bioethanol/cachaça strains of a five-gene cluster (Region B) that is a known phylogenetic signature of European wine yeasts. Combining genomes of H3, H4, and 195 yeast strains, we comprehensively assessed whole-genome phylogeny of these taxa using an alignment-free approach. The 197-genome phylogeny substantiates that bioethanol yeasts are monophyletic and closely related to the cachaça and wine strains. Our results support the hypothesis that biofuel-producing yeasts in Brazil may have been co-opted from a pool of yeasts that were pre-adapted to alcoholic fermentation of sugarcane for the distillation of cachaça spirit, which historically is a much older industry than the large-scale fuel ethanol production.
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Affiliation(s)
- Ana Paula Jacobus
- Laboratory for Genomics and Experimental Evolution of Yeasts, Institute for Bioenergy Research, São Paulo State University, Rio Claro, Brazil
| | - Timothy G Stephens
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Pierre Youssef
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Raul González-Pech
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia
| | - Michael M Ciccotosto-Camp
- Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Katherine E Dougan
- Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Yibi Chen
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.,Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Luiz Carlos Basso
- Biological Science Department, Escola Superior de Agricultura Luiz de Queiroz, University of São Paulo (USP), Piracicaba, Brazil
| | - Jeverson Frazzon
- Institute of Food Science and Technology, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
| | - Cheong Xin Chan
- Institute for Molecular Bioscience, The University of Queensland, Brisbane, QLD, Australia.,Australian Centre for Ecogenomics, The University of Queensland, Brisbane, QLD, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD, Australia
| | - Jeferson Gross
- Laboratory for Genomics and Experimental Evolution of Yeasts, Institute for Bioenergy Research, São Paulo State University, Rio Claro, Brazil
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