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Pongcharoen P, Tawong W, Pathaichindachote W, Rod-In W. Physiological responses contributing to multiple stress tolerance in Pichia kudriavzevii with potential enhancement for ethanol fermentation. J Biosci Bioeng 2024; 138:314-323. [PMID: 39098474 DOI: 10.1016/j.jbiosc.2024.07.012] [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: 04/27/2024] [Revised: 06/28/2024] [Accepted: 07/15/2024] [Indexed: 08/06/2024]
Abstract
Economically feasible ethanol production requires efficient hydrolysis of lignocellulosic biomass and high-temperature processing to enable simultaneous saccharification and fermentation. During the lignocellulolysic hydrolysate, the yeast must encounter with a multiple of inhibitors such as heat and furfural. To solve this problem, a potential fermentative yeast strain that tolerated simultaneous multistress and enhance ethanol concentration was investigated. Twenty yeast isolates were classified into two major yeast species, namely Pichia kudriavzevii (twelve isolates) and Candida tropicalis (eight isolates). All P. kudriavzevii isolates were able to grow at high temperature (45 °C) and exhibited stress tolerance toward furfural. Among P. kudriavzevii isolates, NUCG-S3 presented the highest specific growth rate under each stress condition of heat and furfural, and multistress. Morphological changes in P. kudriavzevii isolates (NUCG-S2, NUCG-S3, NUKL-P1, NUKL-P3, and NUOR-J1) showed alteration in mean cell length and width compared to the non-stress condition. Ethanol production by glucose was also determined. The yeast strain, NUCG-S3, gave the highest ethanol concentrations at 99.46 ± 0.82, 62.23 ± 0.96, and 65.80 ± 0.62 g/l (P < 0.05) under temperature of 30 °C, 40 °C, and 42 °C, respectively. The tolerant isolated yeast NUCG-S3 achieved ethanol production of 53.58 ± 3.36 and 48.06 ± 3.31 g/l (P < 0.05) in the presence of 15 mM furfural and multistress (42 °C with 15 mM furfural), respectively. Based on the results of the present study, the novel thermos and furfural-tolerant yeast strain P. kudriavzevii NUCG-S3 showed promise as a highly proficient yeast for high-temperature ethanol fermentation.
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Affiliation(s)
- Pongsanat Pongcharoen
- Department of Agricultural Science, Faculty of Agriculture, Natural Resources and Environment, Naresuan University, Phitsanulok 65000, Thailand; Center of Excellence in Research for Agricultural Biotechnology, Naresuan University, Phitsanulok 65000, Thailand.
| | - Wittaya Tawong
- Department of Agricultural Science, Faculty of Agriculture, Natural Resources and Environment, Naresuan University, Phitsanulok 65000, Thailand; Center of Excellence in Research for Agricultural Biotechnology, Naresuan University, Phitsanulok 65000, Thailand.
| | - Wanwarang Pathaichindachote
- Department of Agricultural Science, Faculty of Agriculture, Natural Resources and Environment, Naresuan University, Phitsanulok 65000, Thailand; Center of Excellence in Research for Agricultural Biotechnology, Naresuan University, Phitsanulok 65000, Thailand.
| | - Weerawan Rod-In
- Department of Agricultural Science, Faculty of Agriculture, Natural Resources and Environment, Naresuan University, Phitsanulok 65000, Thailand; Center of Excellence in Research for Agricultural Biotechnology, Naresuan University, Phitsanulok 65000, Thailand.
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Kurniawan E, Leamdum C, Imai T, O-Thong S. Exploiting the Thermotolerance of Clostridium Strain M1NH for Efficient Caproic Acid Fermentation from Ethanol and Acetic Acid. Curr Microbiol 2024; 81:244. [PMID: 38935285 DOI: 10.1007/s00284-024-03780-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: 11/05/2023] [Accepted: 06/21/2024] [Indexed: 06/28/2024]
Abstract
A novel thermotolerant caproic acid-producing bacterial strain, Clostridium M1NH, was successfully isolated from sewage sludge. Ethanol and acetic acid at a molar ratio of 4:1 proved to be the optimal substrates, yielding a maximum caproic acid production of 3.5 g/L. Clostridium M1NH exhibited remarkable tolerance to high concentrations of ethanol (up to 5% v/v), acetic acid (up to 5% w/v), and caproic acid (up to 2% w/v). The strain also demonstrated a wide pH tolerance range (pH 5.5-7.5) and an elevated temperature optimum between 35 and 40 °C. Phylogenetic analysis based on 16S rRNA gene sequences revealed that Clostridium M1NH shares a 98% similarity with Clostridium luticellarii DSM 29923 T. The robustness of strain M1NH and its efficient caproic acid production from low-cost substrates highlight its potential for sustainable bio-based chemical production. The maximum caproic acid yield achieved by Clostridium M1NH was 1.6-fold higher than that reported for C. kluyveri under similar fermentation conditions. This study opens new avenues for valorizing waste streams and advancing a circular economy model in the chemical industry.
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Affiliation(s)
- Edy Kurniawan
- Biofuel and Biocatalysis Innovation Research Unit, Nakhonsawan Campus, Mahidol University, Nakhonsawan, 60130, Thailand
| | | | - Tsuyoshi Imai
- Graduate School of Sciences and Technology for Innovation, Yamaguchi University, Yamaguchi, 755-8611, Japan
| | - Sompong O-Thong
- Biofuel and Biocatalysis Innovation Research Unit, Nakhonsawan Campus, Mahidol University, Nakhonsawan, 60130, Thailand.
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Demeke MM, Echemendia D, Belo E, Foulquié-Moreno MR, Thevelein JM. Enhancing xylose-fermentation capacity of engineered Saccharomyces cerevisiae by multistep evolutionary engineering in inhibitor-rich lignocellulose hydrolysate. FEMS Yeast Res 2024; 24:foae013. [PMID: 38604750 PMCID: PMC11062418 DOI: 10.1093/femsyr/foae013] [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: 12/26/2023] [Revised: 02/19/2024] [Accepted: 04/10/2024] [Indexed: 04/13/2024] Open
Abstract
Major progress in developing Saccharomyces cerevisiae strains that utilize the pentose sugar xylose has been achieved. However, the high inhibitor content of lignocellulose hydrolysates still hinders efficient xylose fermentation, which remains a major obstacle for commercially viable second-generation bioethanol production. Further improvement of xylose utilization in inhibitor-rich lignocellulose hydrolysates remains highly challenging. In this work, we have developed a robust industrial S. cerevisiae strain able to efficiently ferment xylose in concentrated undetoxified lignocellulose hydrolysates. This was accomplished with novel multistep evolutionary engineering. First, a tetraploid strain was generated and evolved in xylose-enriched pretreated spruce biomass. The best evolved strain was sporulated to obtain a genetically diverse diploid population. The diploid strains were then screened in industrially relevant conditions. The best performing strain, MDS130, showed superior fermentation performance in three different lignocellulose hydrolysates. In concentrated corncob hydrolysate, with initial cell density of 1 g DW/l, at 35°C, MDS130 completely coconsumed glucose and xylose, producing ± 7% v/v ethanol with a yield of 91% of the maximum theoretical value and an overall productivity of 1.22 g/l/h. MDS130 has been developed from previous industrial yeast strains without applying external mutagenesis, minimizing the risk of negative side-effects on other commercially important properties and maximizing its potential for industrial application.
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Affiliation(s)
- Mekonnen M Demeke
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
- NovelYeast bv, Bio-incubator BIO4, Gaston Geenslaan 3, 3001 Leuven-Heverlee, Belgium
| | - Dannele Echemendia
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Edgard Belo
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - María R Foulquié-Moreno
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
| | - Johan M Thevelein
- Laboratory of Molecular Cell Biology, Institute of Botany and Microbiology, KU Leuven, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Belgium
- Center for Microbiology, VIB, Kasteelpark Arenberg 31, B-3001 Leuven-Heverlee, Flanders, Belgium
- NovelYeast bv, Bio-incubator BIO4, Gaston Geenslaan 3, 3001 Leuven-Heverlee, Belgium
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Yao L, Jia Y, Zhang Q, Zheng X, Yang H, Dai J, Chen X. Adaptive laboratory evolution to obtain furfural tolerant Saccharomyces cerevisiae for bioethanol production and the underlying mechanism. Front Microbiol 2024; 14:1333777. [PMID: 38239732 PMCID: PMC10794740 DOI: 10.3389/fmicb.2023.1333777] [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: 11/06/2023] [Accepted: 12/05/2023] [Indexed: 01/22/2024] Open
Abstract
Introduction Furfural, a main inhibitor produced during pretreatment of lignocellulose, has shown inhibitory effects on S. cerevisiae. Method In the present study, new strains named 12-1 with enhanced resistance to furfural were obtained through adaptive laboratory evolution, which exhibited a shortened lag phase by 36 h, and an increased ethanol conversion rate by 6.67% under 4 g/L furfural. Results and Discussion To further explore the mechanism of enhanced furfural tolerance, ADR1_1802 mutant was constructed by CRISPR/Cas9 technology, based on whole genome re-sequencing data. The results indicated that the time when ADR1_1802 begin to grow was shortened by 20 h compared with reference strain (S. cerevisiae CEN.PK113-5D) when furfural was 4 g/L. Additionally, the transcription levels of GRE2 and ADH6 in ADR1_ 1802 mutant were increased by 53.69 and 44.95%, respectively, according to real-time fluorescence quantitative PCR analysis. These findings suggest that the enhanced furfural tolerance of mutant is due to accelerated furfural degradation. Importance: Renewable carbon worldwide is vital to achieve "zero carbon" target. Bioethanol obtained from biomass is one of them. To make bioethanol price competitive to fossil fuel, higher ethanol yield is necessary, therefore, monosaccharide produced during biomass pretreatment should be effectively converted to ethanol by Saccharomyces cerevisiae. However, inhibitors formed by glucose or xylose oxidation could make ethanol yield lower. Thus, inhibitor tolerant Saccharomyces cerevisiae is important to this process. As one of the main component of pretreatment hydrolysate, furfural shows obvious impact on growth and ethanol production of Saccharomyces cerevisiae. To get furfural tolerant Saccharomyces cerevisiae and find the underlying mechanism, adaptive laboratory evolution and CRISPR/Cas9 technology were applied in the present study.
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Affiliation(s)
- Lan Yao
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Youpiao Jia
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Qingyan Zhang
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Xueyun Zheng
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Haitao Yang
- Hubei Provincial Key Laboratory of Green Materials for Light Industry, Hubei University of Technology, Wuhan, China
| | - Jun Dai
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), College of Bioengineering, Hubei University of Technology, Wuhan, China
| | - Xiong Chen
- Key Laboratory of Fermentation Engineering (Ministry of Education), Cooperative Innovation Center of Industrial Fermentation (Ministry of Education and Hubei Province), College of Bioengineering, Hubei University of Technology, Wuhan, China
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Bitew D, Tesfaye A, Andualem B. Isolation, screening and identification of ethanol producing yeasts from Ethiopian fermented beverages. BIOTECHNOLOGY REPORTS (AMSTERDAM, NETHERLANDS) 2023; 40:e00815. [PMID: 37876548 PMCID: PMC10590766 DOI: 10.1016/j.btre.2023.e00815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2023] [Revised: 08/25/2023] [Accepted: 10/02/2023] [Indexed: 10/26/2023]
Abstract
The growing demand for renewable energy sources such as bioethanol is facing a lack of efficient ethanologenic microbes. This study aimed to isolate and screen ethanologenic yeasts from Ethiopian fermented beverages. A progressive screening and selection approach was employed. Selected isolates were evaluated for bioethanol production using banana peel waste as substrate. A total of 102 isolates were obtained. Sixteen isolates were selected based on their tolerance to stress conditions and carbohydrate fermentation and assimilation capacity. Most found moderately tolerant to 10 %, but slightly tolerant at 15 and 20 % (v/v) ethanol concentration. They yield 15.3 to 20.1 g/L and 9.1 ± 0.6 to 12.9 ± 1.3 g/L ethanol from 2 % (w/v) glucose and 80 g/L banana peel, respectively. Molecular characterization identified them as Saccharomyces cerevisiae strains. Results demonstrate insight about their potential role in the ethanol industry. Optimization of the fermentation conditions is recommended.
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Affiliation(s)
- Dagnew Bitew
- Department of Biology, Mizan-Tepi University, P. BOX: 260, Ethiopia
- Institute of Biotechnology, University of Gondar, P.BOX: 196, Ethiopia
| | - Anteneh Tesfaye
- Institute of Biotechnology, Addis Ababa University, P.BOX: 1176, Ethiopia
- BioTEI, Winnipeg, Manitoba, Canada
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Eliodório KP, Cunha GCDGE, Lino FSDO, Sommer MOA, Gombert AK, Giudici R, Basso TO. Physiology of Saccharomyces cerevisiae during growth on industrial sugar cane molasses can be reproduced in a tailor-made defined synthetic medium. Sci Rep 2023; 13:10567. [PMID: 37386049 PMCID: PMC10310838 DOI: 10.1038/s41598-023-37618-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 06/24/2023] [Indexed: 07/01/2023] Open
Abstract
Fully defined laboratory media have the advantage of allowing for reproducibility and comparability of results among different laboratories, as well as being suitable for the investigation of how different individual components affect microbial or process performance. We developed a fully defined medium that mimics sugarcane molasses, a frequently used medium in different industrial processes where yeast is cultivated. The medium, named 2SMol, builds upon a previously published semi-defined formulation and is conveniently prepared from some stock solutions: C-source, organic N, inorganic N, organic acids, trace elements, vitamins, Mg + K, and Ca. We validated the 2SMol recipe in a scaled-down sugarcane biorefinery model, comparing the physiology of Saccharomyces cerevisiae in different actual molasses-based media. We demonstrate the flexibility of the medium by investigating the effect of nitrogen availability on the ethanol yield during fermentation. Here we present in detail the development of a fully defined synthetic molasses medium and the physiology of yeast strains in this medium compared to industrial molasses. This tailor-made medium was able to satisfactorily reproduce the physiology of S. cerevisiae in industrial molasses. Thus, we hope the 2SMol formulation will be valuable to researchers both in academia and industry to obtain new insights and developments in industrial yeast biotechnology.
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Affiliation(s)
- Kevy Pontes Eliodório
- Department of Chemical Engineering, Escola Politécnica, Universidade de São Paulo, Av. Prof. Luciano Gualberto, 380, São Paulo, SP, 05508-010, Brazil
| | - Gabriel Caetano de Gois E Cunha
- Department of Chemical Engineering, Escola Politécnica, Universidade de São Paulo, Av. Prof. Luciano Gualberto, 380, São Paulo, SP, 05508-010, Brazil
| | | | - Morten Otto Alexander Sommer
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, 2800, Kongens Lyngby, Denmark
| | - Andreas Karoly Gombert
- School of Food Engineering, University of Campinas, R. Monteiro Lobato 80, Campinas, 13083-862, Brazil
| | - Reinaldo Giudici
- Department of Chemical Engineering, Escola Politécnica, Universidade de São Paulo, Av. Prof. Luciano Gualberto, 380, São Paulo, SP, 05508-010, Brazil
| | - Thiago Olitta Basso
- Department of Chemical Engineering, Escola Politécnica, Universidade de São Paulo, Av. Prof. Luciano Gualberto, 380, São Paulo, SP, 05508-010, Brazil.
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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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Identification of a New Endo-β-1,4-xylanase Prospected from the Microbiota of the Termite Heterotermes tenuis. Microorganisms 2022; 10:microorganisms10050906. [PMID: 35630351 PMCID: PMC9143652 DOI: 10.3390/microorganisms10050906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 12/04/2022] Open
Abstract
Xylanases are hemicellulases that break down xylan to soluble pentoses. They are used for industrial purposes, such as paper whitening, beverage clarification, and biofuel production. The second-generation bioethanol production is hindered by the enzymatic hydrolysis step of the lignocellulosic biomass, due to the complex arrangement established among its constituents. Xylanases can potentially increase the production yield by improving the action of the cellulolytic enzyme complex. We prospected endo-β-1,4-xylanases from meta-transcriptomes of the termite Heterotermes tenuis. In silico structural characterization and functional analysis of an endo-β-1,4-xylanase from a symbiotic protist of H. tenuis indicate two active sites and a substrate-binding groove needed for the catalytic activity. No N-glycosylation sites were found. This endo-β-1,4-xylanase was recombinantly expressed in Pichia pastoris and Escherichia coli cells, presenting a molecular mass of approximately 20 kDa. Enzymatic activity assay using recombinant endo-β-1,4-xylanase was also performed on 1% xylan agar stained with Congo red at 30 °C and 40 °C. The enzyme expressed in both systems was able to hydrolyze the substrate xylan, becoming a promising candidate for further analysis aiming to determine its potential for application in industrial xylan degradation processes.
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Patel AK, Saini JK, Singhania RR. Development of multiple inhibitor tolerant yeast via adaptive laboratory evolution for sustainable bioethanol production. BIORESOURCE TECHNOLOGY 2022; 344:126247. [PMID: 34740795 DOI: 10.1016/j.biortech.2021.126247] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/24/2021] [Accepted: 10/26/2021] [Indexed: 06/13/2023]
Abstract
The present research work aimed at developing robust yeast cell factory via adaptive laboratory evolution (ALE) for improved cellulosic bioethanol production. Kluyveromyces marxianus JKH5, a newly isolated thermotolerant ethanologenic yeast, was engineered by serial passaging for 60 generations in medium supplemented with gradually higher concentration of inhibitors (acetic acid, furfural, and vanillin) that are generated during dilute acid pretreatment. The improved strain K. marxianus JKH5 C60, showed 3.3-fold higher specific growth rate, 56% reduced lag phase and 80% enhanced fermentation efficiency at 42 °C in comparison to parent strain in inhibitor cocktail comprising medium. Bioethanol production by simultaneous saccharification and fermentation of sequential dilute acid-alkali pretreated sugarcane bagasse in presence of inhibitors, resulted in ethanol titre and yield, respectively, 54.8 ± 0.9 g/L and 0.40 g/g. The adapted yeast can be used to ferment unwashed pretreated biomass, thereby, reducing overall cost, time, and wastewater generation, hence making bioethanol production sustainable.
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Affiliation(s)
- Anil Kumar Patel
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 81157, Taiwan
| | - Jitendra Kumar Saini
- Department of Microbiology, Central University of Haryana, Mahendergarh, Haryana 123031, India.
| | - Reeta Rani Singhania
- Department of Marine Environmental Engineering, National Kaohsiung University of Science and Technology, Kaohsiung City 81157, Taiwan
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Coradini ALV, da Silveira Bezerra de Mello F, Furlan M, Maneira C, Carazzolle MF, Pereira GAG, Teixeira GS. QTL mapping of a Brazilian bioethanol strain links the cell wall protein-encoding gene GAS1 to low pH tolerance in S. cerevisiae. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:239. [PMID: 34915919 PMCID: PMC8675505 DOI: 10.1186/s13068-021-02079-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Accepted: 11/17/2021] [Indexed: 06/14/2023]
Abstract
BACKGROUND Saccharomyces cerevisiae is largely applied in many biotechnological processes, from traditional food and beverage industries to modern biofuel and biochemicals factories. During the fermentation process, yeast cells are usually challenged in different harsh conditions, which often impact productivity. Regarding bioethanol production, cell exposure to acidic environments is related to productivity loss on both first- and second-generation ethanol. In this scenario, indigenous strains traditionally used in fermentation stand out as a source of complex genetic architecture, mainly due to their highly robust background-including low pH tolerance. RESULTS In this work, we pioneer the use of QTL mapping to uncover the genetic basis that confers to the industrial strain Pedra-2 (PE-2) acidic tolerance during growth at low pH. First, we developed a fluorescence-based high-throughput approach to collect a large number of haploid cells using flow cytometry. Then, we were able to apply a bulk segregant analysis to solve the genetic basis of low pH resistance in PE-2, which uncovered a region in chromosome X as the major QTL associated with the evaluated phenotype. A reciprocal hemizygosity analysis revealed the allele GAS1, encoding a β-1,3-glucanosyltransferase, as the casual variant in this region. The GAS1 sequence alignment of distinct S. cerevisiae strains pointed out a non-synonymous mutation (A631G) prevalence in wild-type isolates, which is absent in laboratory strains. We further showcase that GAS1 allele swap between PE-2 and a low pH-susceptible strain can improve cell viability on the latter of up to 12% after a sulfuric acid wash process. CONCLUSION This work revealed GAS1 as one of the main causative genes associated with tolerance to growth at low pH in PE-2. We also showcase how GAS1PE-2 can improve acid resistance of a susceptible strain, suggesting that these findings can be a powerful foundation for the development of more robust and acid-tolerant strains. Our results collectively show the importance of tailored industrial isolated strains in discovering the genetic architecture of relevant traits and its implications over productivity.
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Affiliation(s)
- Alessandro L V Coradini
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
- Molecular and Computational Biology Section, Department of Biological Sciences, University of Southern California, Los Angeles, CA, 90089-2910, USA
| | - Fellipe da Silveira Bezerra de Mello
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
| | - Monique Furlan
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
| | - Carla Maneira
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
| | - Marcelo F Carazzolle
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
| | - Gonçalo Amarante Guimaraes Pereira
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil.
| | - Gleidson Silva Teixeira
- Department of Genetics, Evolution, Microbiology, and Immunology, Institute of Biology, University of Campinas, Rua Monteiro Lobato 255, Campinas, 13083-862, Brazil
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Process Intensification in Bio-Ethanol Production–Recent Developments in Membrane Separation. Processes (Basel) 2021. [DOI: 10.3390/pr9061028] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Ethanol is considered as a renewable transport fuels and demand is expected to grow. In this work, trends related to bio-ethanol production are described using Thailand as an example. Developments on high-temperature fermentation and membrane technologies are also explained. This study focuses on the application of membranes in ethanol recovery after fermentation. A preliminary simulation was performed to compare different process configurations to concentrate 10 wt% ethanol to 99.5 wt% using membranes. In addition to the significant energy reduction achieved by replacing azeotropic distillation with membrane dehydration, employing ethanol-selective membranes can further reduce energy demand. Silicalite membrane is a type of membrane showing one of the highest ethanol-selective permeation performances reported today. A silicalite membrane was applied to separate a bio-ethanol solution produced via high-temperature fermentation followed by a single distillation. The influence of contaminants in the bio-ethanol on the membrane properties and required further developments are also discussed.
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12
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Rodrigues CIS, Wahl A, Gombert AK. Aerobic growth physiology of Saccharomyces cerevisiae on sucrose is strain-dependent. FEMS Yeast Res 2021; 21:6214418. [PMID: 33826723 DOI: 10.1093/femsyr/foab021] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 04/01/2021] [Indexed: 12/22/2022] Open
Abstract
Present knowledge on the quantitative aerobic physiology of the yeast Saccharomyces cerevisiae during growth on sucrose as sole carbon and energy source is limited to either adapted cells or to the model laboratory strain CEN.PK113-7D. To broaden our understanding of this matter and open novel opportunities for sucrose-based biotechnological processes, we characterized three strains, with distinct backgrounds, during aerobic batch bioreactor cultivations. Our results reveal that sucrose metabolism in S. cerevisiae is a strain-specific trait. Each strain displayed distinct extracellular hexose concentrations and invertase activity profiles. Especially, the inferior maximum specific growth rate (0.21 h-1) of the CEN.PK113-7D strain, with respect to that of strains UFMG-CM-Y259 (0.37 h-1) and JP1 (0.32 h-1), could be associated to its low invertase activity (0.04-0.09 U/mgDM). Moreover, comparative experiments with glucose or fructose alone, or in combination, suggest mixed mechanisms of sucrose utilization by the industrial strain JP1, and points out the remarkable ability of the wild isolate UFMG-CM-259 to grow faster on sucrose than on glucose in a well-controlled cultivation system. This work hints to a series of metabolic traits that can be exploited to increase sucrose catabolic rates and bioprocess efficiency.
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Affiliation(s)
- Carla Inês Soares Rodrigues
- School of Food Engineering, University of Campinas, Rua Monteiro Lobato 80, 13083-862, Campinas, SP, Brazil.,Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
| | - Aljoscha Wahl
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ Delft, The Netherlands
| | - Andreas K Gombert
- School of Food Engineering, University of Campinas, Rua Monteiro Lobato 80, 13083-862, Campinas, SP, Brazil
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