Kluyveromyces marxianus developing ethanol tolerance during adaptive evolution with significant improvements of multiple pathways
Abstract Background Kluyveromyces marxianus, the known fastest-growing eukaryote on the earth, has remarkable thermotolerance and capacity to utilize various agricultural residues to produce low-cost bioethanol, and hence is industrially important to resolve the imminent energy shortage crisis. Curr...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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BMC
2019-03-01
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| Series: | Biotechnology for Biofuels |
| Subjects: | |
| Online Access: | http://link.springer.com/article/10.1186/s13068-019-1393-z |
| _version_ | 1818554197545582592 |
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| author | Wenjuan Mo Mengzhu Wang Rongrong Zhan Yao Yu Yungang He Hong Lu |
| author_facet | Wenjuan Mo Mengzhu Wang Rongrong Zhan Yao Yu Yungang He Hong Lu |
| author_sort | Wenjuan Mo |
| collection | DOAJ |
| description | Abstract Background Kluyveromyces marxianus, the known fastest-growing eukaryote on the earth, has remarkable thermotolerance and capacity to utilize various agricultural residues to produce low-cost bioethanol, and hence is industrially important to resolve the imminent energy shortage crisis. Currently, the poor ethanol tolerance hinders its operable application in the industry, and it is necessary to improve K. marxianus’ ethanol resistance and unravel the underlying systematical mechanisms. However, this has been seldom reported to date. Results We carried out a wild-type haploid K. marxianus FIM1 in adaptive evolution in 6% (v/v) ethanol. After 100-day evolution, the KM-100d population was obtained; its ethanol tolerance increased up to 10% (v/v). Interestingly, DNA analysis and RNA-seq analysis showed that KM-100d yeasts’ ethanol tolerance improvement was not due to ploidy change or meaningful mutations, but founded on transcriptional reprogramming in a genome-wide range. Even growth in an ethanol-free medium, many genes in KM-100d maintained their up-regulation. Especially, pathways of ethanol consumption, membrane lipid biosynthesis, anti-osmotic pressure, anti-oxidative stress, and protein folding were generally up-regulated in KM-100d to resist ethanol. Notably, enhancement of the secretory pathway may be the new strategy KM-100d developed to anti-osmotic pressure, instead of the traditional glycerol production way in S. cerevisiae. Inferred from the transcriptome data, besides ethanol tolerance, KM-100d may also develop the ability to resist osmotic, oxidative, and thermic stresses, and this was further confirmed by the cell viability test. Furthermore, under such environmental stresses, KM-100d greatly improved ethanol production than the original strain. In addition, we found that K. marxianus may adopt distinct routes to resist different ethanol concentrations. Trehalose biosynthesis was required for low ethanol, while sterol biosynthesis and the whole secretory pathway were activated for high ethanol. Conclusions This study reveals that ethanol-driven laboratory evolution could improve K. marxianus’ ethanol tolerance via significant up-regulation of multiple pathways including anti-osmotic, anti-oxidative, and anti-thermic processes, and indeed consequently raised ethanol yield in industrial high-temperature and high-ethanol circumstance. Our findings give genetic clues for further rational optimization of K. marxianus’ ethanol production, and also partly confirm the positively correlated relationship between yeast’s ethanol tolerance and production. |
| first_indexed | 2024-12-12T09:36:12Z |
| format | Article |
| id | doaj.art-8fddd1158045418587e16d999d80bc52 |
| institution | Directory Open Access Journal |
| issn | 1754-6834 |
| language | English |
| last_indexed | 2024-12-12T09:36:12Z |
| publishDate | 2019-03-01 |
| publisher | BMC |
| record_format | Article |
| series | Biotechnology for Biofuels |
| spelling | doaj.art-8fddd1158045418587e16d999d80bc522022-12-22T00:28:43ZengBMCBiotechnology for Biofuels1754-68342019-03-0112111510.1186/s13068-019-1393-zKluyveromyces marxianus developing ethanol tolerance during adaptive evolution with significant improvements of multiple pathwaysWenjuan Mo0Mengzhu Wang1Rongrong Zhan2Yao Yu3Yungang He4Hong Lu5State Key Laboratory of Genetic Engineering, School of Life Science, Fudan UniversityState Key Laboratory of Genetic Engineering, School of Life Science, Fudan UniversityState Key Laboratory of Genetic Engineering, School of Life Science, Fudan UniversityState Key Laboratory of Genetic Engineering, School of Life Science, Fudan UniversityKey Laboratory of Medical Epigenetics and Metabolism, Institutes of Biomedical Sciences, Fudan UniversityState Key Laboratory of Genetic Engineering, School of Life Science, Fudan UniversityAbstract Background Kluyveromyces marxianus, the known fastest-growing eukaryote on the earth, has remarkable thermotolerance and capacity to utilize various agricultural residues to produce low-cost bioethanol, and hence is industrially important to resolve the imminent energy shortage crisis. Currently, the poor ethanol tolerance hinders its operable application in the industry, and it is necessary to improve K. marxianus’ ethanol resistance and unravel the underlying systematical mechanisms. However, this has been seldom reported to date. Results We carried out a wild-type haploid K. marxianus FIM1 in adaptive evolution in 6% (v/v) ethanol. After 100-day evolution, the KM-100d population was obtained; its ethanol tolerance increased up to 10% (v/v). Interestingly, DNA analysis and RNA-seq analysis showed that KM-100d yeasts’ ethanol tolerance improvement was not due to ploidy change or meaningful mutations, but founded on transcriptional reprogramming in a genome-wide range. Even growth in an ethanol-free medium, many genes in KM-100d maintained their up-regulation. Especially, pathways of ethanol consumption, membrane lipid biosynthesis, anti-osmotic pressure, anti-oxidative stress, and protein folding were generally up-regulated in KM-100d to resist ethanol. Notably, enhancement of the secretory pathway may be the new strategy KM-100d developed to anti-osmotic pressure, instead of the traditional glycerol production way in S. cerevisiae. Inferred from the transcriptome data, besides ethanol tolerance, KM-100d may also develop the ability to resist osmotic, oxidative, and thermic stresses, and this was further confirmed by the cell viability test. Furthermore, under such environmental stresses, KM-100d greatly improved ethanol production than the original strain. In addition, we found that K. marxianus may adopt distinct routes to resist different ethanol concentrations. Trehalose biosynthesis was required for low ethanol, while sterol biosynthesis and the whole secretory pathway were activated for high ethanol. Conclusions This study reveals that ethanol-driven laboratory evolution could improve K. marxianus’ ethanol tolerance via significant up-regulation of multiple pathways including anti-osmotic, anti-oxidative, and anti-thermic processes, and indeed consequently raised ethanol yield in industrial high-temperature and high-ethanol circumstance. Our findings give genetic clues for further rational optimization of K. marxianus’ ethanol production, and also partly confirm the positively correlated relationship between yeast’s ethanol tolerance and production.http://link.springer.com/article/10.1186/s13068-019-1393-zKluyveromyces marxianusEthanol toleranceAdaptive evolutionRNA-seq analysisMultiple-stress tolerance |
| spellingShingle | Wenjuan Mo Mengzhu Wang Rongrong Zhan Yao Yu Yungang He Hong Lu Kluyveromyces marxianus developing ethanol tolerance during adaptive evolution with significant improvements of multiple pathways Biotechnology for Biofuels Kluyveromyces marxianus Ethanol tolerance Adaptive evolution RNA-seq analysis Multiple-stress tolerance |
| title | Kluyveromyces marxianus developing ethanol tolerance during adaptive evolution with significant improvements of multiple pathways |
| title_full | Kluyveromyces marxianus developing ethanol tolerance during adaptive evolution with significant improvements of multiple pathways |
| title_fullStr | Kluyveromyces marxianus developing ethanol tolerance during adaptive evolution with significant improvements of multiple pathways |
| title_full_unstemmed | Kluyveromyces marxianus developing ethanol tolerance during adaptive evolution with significant improvements of multiple pathways |
| title_short | Kluyveromyces marxianus developing ethanol tolerance during adaptive evolution with significant improvements of multiple pathways |
| title_sort | kluyveromyces marxianus developing ethanol tolerance during adaptive evolution with significant improvements of multiple pathways |
| topic | Kluyveromyces marxianus Ethanol tolerance Adaptive evolution RNA-seq analysis Multiple-stress tolerance |
| url | http://link.springer.com/article/10.1186/s13068-019-1393-z |
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