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Peri KVR, Yuan L, Faria Oliveira F, Persson K, Alalam HD, Olsson L, Larsbrink J, Kerkhoven EJ, Geijer C. A unique metabolic gene cluster regulates lactose and galactose metabolism in the yeast Candida intermedia. Appl Environ Microbiol 2024:e0113524. [PMID: 39240082 DOI: 10.1128/aem.01135-24] [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: 06/09/2024] [Accepted: 08/19/2024] [Indexed: 09/07/2024] Open
Abstract
Lactose assimilation is a relatively rare trait in yeasts, and Kluyveromyces yeast species have long served as model organisms for studying lactose metabolism. Meanwhile, the metabolic strategies of most other lactose-assimilating yeasts remain unknown. In this work, we have elucidated the genetic determinants of the superior lactose-growing yeast Candida intermedia. Through genomic and transcriptomic analyses, we identified three interdependent gene clusters responsible for the metabolism of lactose and its hydrolysis product galactose: the conserved LAC cluster (LAC12, LAC4) for lactose uptake and hydrolysis, the conserved GAL cluster (GAL1, GAL7, and GAL10) for galactose catabolism through the Leloir pathway, and a "GALLAC" cluster containing the transcriptional activator gene LAC9, second copies of GAL1 and GAL10, and a XYL1 gene encoding an aldose reductase involved in carbon overflow metabolism. Bioinformatic analysis suggests that the GALLAC cluster is unique to C. intermedia and has evolved through gene duplication and divergence, and deletion mutant phenotyping proved that the cluster is indispensable for C. intermedia's growth on lactose and galactose. We also show that the regulatory network in C. intermedia, governed by Lac9 and Gal1 from the GALLAC cluster, differs significantly from the galactose and lactose regulons in Saccharomyces cerevisiae, Kluyveromyces lactis, and Candida albicans. Moreover, although lactose and galactose metabolism are closely linked in C. intermedia, our results also point to important regulatory differences.IMPORTANCEThis study paves the way to a better understanding of lactose and galactose metabolism in the non-conventional yeast C. intermedia. Notably, the unique GALLAC cluster represents a new, interesting example of metabolic network rewiring and likely helps to explain how C. intermedia has evolved into an efficient lactose-assimilating yeast. With the Leloir pathway of budding yeasts acting like a model system for understanding the function, evolution, and regulation of eukaryotic metabolism, this work provides new evolutionary insights into yeast metabolic pathways and regulatory networks. In extension, the results will facilitate future development and use of C. intermedia as a cell-factory for conversion of lactose-rich whey into value-added products.
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Affiliation(s)
- Kameshwara V R Peri
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Le Yuan
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Fábio Faria Oliveira
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Karl Persson
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Hanna D Alalam
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Lisbeth Olsson
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Wallenberg Wood Science Center, Chalmers University of Technology, Gothenburg, Sweden
| | - Johan Larsbrink
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Wallenberg Wood Science Center, Chalmers University of Technology, Gothenburg, Sweden
| | - Eduard J Kerkhoven
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Kongens Lyngby, Denmark
- SciLifeLab, Chalmers University of Technology, Gothenburg, Sweden
| | - Cecilia Geijer
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
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Cámara E, Mormino M, Siewers V, Nygård Y. Saccharomyces cerevisiae strains performing similarly during fermentation of lignocellulosic hydrolysates show pronounced differences in transcriptional stress responses. Appl Environ Microbiol 2024; 90:e0233023. [PMID: 38587374 PMCID: PMC11107148 DOI: 10.1128/aem.02330-23] [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: 12/22/2023] [Accepted: 03/14/2024] [Indexed: 04/09/2024] Open
Abstract
Improving our understanding of the transcriptional changes of Saccharomyces cerevisiae during fermentation of lignocellulosic hydrolysates is crucial for the creation of more efficient strains to be used in biorefineries. We performed RNA sequencing of a CEN.PK laboratory strain, two industrial strains (KE6-12 and Ethanol Red), and two wild-type isolates of the LBCM collection when cultivated anaerobically in wheat straw hydrolysate. Many of the differently expressed genes identified among the strains have previously been reported to be important for tolerance to lignocellulosic hydrolysates or inhibitors therein. Our study demonstrates that stress responses typically identified during aerobic conditions such as glutathione metabolism, osmotolerance, and detoxification processes also are important for anaerobic processes. Overall, the transcriptomic responses were largely strain dependent, and we focused our study on similarities and differences in the transcriptomes of the LBCM strains. The expression of sugar transporter-encoding genes was higher in LBCM31 compared with LBCM109 that showed high expression of genes involved in iron metabolism and genes promoting the accumulation of sphingolipids, phospholipids, and ergosterol. These results highlight different evolutionary adaptations enabling S. cerevisiae to strive in lignocellulosic hydrolysates and suggest novel gene targets for improving fermentation performance and robustness. IMPORTANCE The need for sustainable alternatives to oil-based production of biochemicals and biofuels is undisputable. Saccharomyces cerevisiae is the most commonly used industrial fermentation workhorse. The fermentation of lignocellulosic hydrolysates, second-generation biomass unsuited for food and feed, is still hampered by lowered productivities as the raw material is inhibitory for the cells. In order to map the genetic responses of different S. cerevisiae strains, we performed RNA sequencing of a CEN.PK laboratory strain, two industrial strains (KE6-12 and Ethanol Red), and two wild-type isolates of the LBCM collection when cultivated anaerobically in wheat straw hydrolysate. While the response to inhibitors of S. cerevisiae has been studied earlier, this has in previous studies been done in aerobic conditions. The transcriptomic analysis highlights different evolutionary adaptations among the different S. cerevisiae strains and suggests novel gene targets for improving fermentation performance and robustness.
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Affiliation(s)
- Elena Cámara
- Division of Industrial Biotechnology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Maurizio Mormino
- Division of Industrial Biotechnology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Verena Siewers
- Division of Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Yvonne Nygård
- Division of Industrial Biotechnology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
- VTT Technical Research Centre of Finland, Espoo, Finland
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Barros KO, Mader M, Krause DJ, Pangilinan J, Andreopoulos B, Lipzen A, Mondo SJ, Grigoriev IV, Rosa CA, Sato TK, Hittinger CT. Oxygenation influences xylose fermentation and gene expression in the yeast genera Spathaspora and Scheffersomyces. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2024; 17:20. [PMID: 38321504 PMCID: PMC10848558 DOI: 10.1186/s13068-024-02467-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 01/28/2024] [Indexed: 02/08/2024]
Abstract
BACKGROUND Cost-effective production of biofuels from lignocellulose requires the fermentation of D-xylose. Many yeast species within and closely related to the genera Spathaspora and Scheffersomyces (both of the order Serinales) natively assimilate and ferment xylose. Other species consume xylose inefficiently, leading to extracellular accumulation of xylitol. Xylitol excretion is thought to be due to the different cofactor requirements of the first two steps of xylose metabolism. Xylose reductase (XR) generally uses NADPH to reduce xylose to xylitol, while xylitol dehydrogenase (XDH) generally uses NAD+ to oxidize xylitol to xylulose, creating an imbalanced redox pathway. This imbalance is thought to be particularly consequential in hypoxic or anoxic environments. RESULTS We screened the growth of xylose-fermenting yeast species in high and moderate aeration and identified both ethanol producers and xylitol producers. Selected species were further characterized for their XR and XDH cofactor preferences by enzyme assays and gene expression patterns by RNA-Seq. Our data revealed that xylose metabolism is more redox balanced in some species, but it is strongly affected by oxygen levels. Under high aeration, most species switched from ethanol production to xylitol accumulation, despite the availability of ample oxygen to accept electrons from NADH. This switch was followed by decreases in enzyme activity and the expression of genes related to xylose metabolism, suggesting that bottlenecks in xylose fermentation are not always due to cofactor preferences. Finally, we expressed XYL genes from multiple Scheffersomyces species in a strain of Saccharomyces cerevisiae. Recombinant S. cerevisiae expressing XYL1 from Scheffersomyces xylosifermentans, which encodes an XR without a cofactor preference, showed improved anaerobic growth on xylose as the primary carbon source compared to S. cerevisiae strain expressing XYL genes from Scheffersomyces stipitis. CONCLUSION Collectively, our data do not support the hypothesis that xylitol accumulation occurs primarily due to differences in cofactor preferences between xylose reductase and xylitol dehydrogenase; instead, gene expression plays a major role in response to oxygen levels. We have also identified the yeast Sc. xylosifermentans as a potential source for genes that can be engineered into S. cerevisiae to improve xylose fermentation and biofuel production.
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Affiliation(s)
- Katharina O Barros
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
- Laboratory of Genetics, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA
- Departamento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Megan Mader
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
| | - David J Krause
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA
- Laboratory of Genetics, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA
| | - Jasmyn Pangilinan
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Bill Andreopoulos
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Computer Science, San Jose State University, One Washington Square, San Jose, CA, USA
| | - Anna Lipzen
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Stephen J Mondo
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Agricultural Biology, Colorado State University, Fort Collins, CO, USA
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Igor V Grigoriev
- U.S. Department of Energy Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Plant and Microbial Department, University of California Berkeley, Berkeley, CA, USA
| | - Carlos A Rosa
- Departamento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Trey K Sato
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA.
| | - Chris Todd Hittinger
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, WI, USA.
- Laboratory of Genetics, Wisconsin Energy Institute, J. F. Crow Institute for the Study of Evolution, Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, WI, USA.
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Mierke F, Brink DP, Norbeck J, Siewers V, Andlid T. Functional genome annotation and transcriptome analysis of Pseudozyma hubeiensis BOT-O, an oleaginous yeast that utilizes glucose and xylose at equal rates. Fungal Genet Biol 2023; 166:103783. [PMID: 36870442 DOI: 10.1016/j.fgb.2023.103783] [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: 05/06/2022] [Revised: 02/10/2023] [Accepted: 02/27/2023] [Indexed: 03/06/2023]
Abstract
Pseudozyma hubeiensis is a basidiomycete yeast that has the highly desirable traits for lignocellulose valorisation of being equally efficient at utilization of glucose and xylose, and capable of their co-utilization. The species has previously mainly been studied for its capacity to produce secreted biosurfactants in the form of mannosylerythritol lipids, but it is also an oleaginous species capable of accumulating high levels of triacylglycerol storage lipids during nutrient starvation. In this study, we aimed to further characterize the oleaginous nature of P. hubeiensis by evaluating metabolism and gene expression responses during storage lipid formation conditions with glucose or xylose as a carbon source. The genome of the recently isolated P. hubeiensis BOT-O strain was sequenced using MinION long-read sequencing and resulted in the most contiguous P. hubeiensis assembly to date with 18.95 Mb in 31 contigs. Using transcriptome data as experimental support, we generated the first mRNA-supported P. hubeiensis genome annotation and identified 6540 genes. 80% of the predicted genes were assigned functional annotations based on protein homology to other yeasts. Based on the annotation, key metabolic pathways in BOT-O were reconstructed, including pathways for storage lipids, mannosylerythritol lipids and xylose assimilation. BOT-O was confirmed to consume glucose and xylose at equal rates, but during mixed glucose-xylose cultivation glucose was found to be taken up faster. Differential expression analysis revealed that only a total of 122 genes were significantly differentially expressed at a cut-off of |log2 fold change| ≥ 2 when comparing cultivation on xylose with glucose, during exponential growth and during nitrogen-starvation. Of these 122 genes, a core-set of 24 genes was identified that were differentially expressed at all time points. Nitrogen-starvation resulted in a larger transcriptional effect, with a total of 1179 genes with significant expression changes at the designated fold change cut-off compared with exponential growth on either glucose or xylose.
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Affiliation(s)
- Friederike Mierke
- Food and Nutrition Science, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden; Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Daniel P Brink
- Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden; Applied Microbiology, Department of Chemistry, Lund University, Lund, Sweden
| | - Joakim Norbeck
- Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Verena Siewers
- Systems and Synthetic Biology, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden.
| | - Thomas Andlid
- Food and Nutrition Science, Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
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Barros KO, Alvarenga FBM, Magni G, Souza GFL, Abegg MA, Palladino F, da Silva SS, Rodrigues RCLB, Sato TK, Hittinger CT, Rosa CA. The Brazilian Amazonian rainforest harbors a high diversity of yeasts associated with rotting wood, including many candidates for new yeast species. Yeast 2023; 40:84-101. [PMID: 36582015 DOI: 10.1002/yea.3837] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/20/2022] [Accepted: 12/27/2022] [Indexed: 12/31/2022] Open
Abstract
This study investigated the diversity of yeast species associated with rotting wood in Brazilian Amazonian rainforests. A total of 569 yeast strains were isolated from rotting wood samples collected in three Amazonian areas (Universidade Federal do Amazonas-Universidade Federal do Amazonas [UFAM], Piquiá, and Carú) in the municipality of Itacoatiara, Amazon state. The samples were cultured in yeast nitrogen base (YNB)-d-xylose, YNB-xylan, and sugarcane bagasse and corncob hemicellulosic hydrolysates (undiluted and diluted 1:2 and 1:5). Sugiyamaella was the most prevalent genus identified in this work, followed by Kazachstania. The most frequently isolated yeast species were Schwanniomyces polymorphus, Scheffersomyces amazonensis, and Wickerhamomyces sp., respectively. The alpha diversity analyses showed that the dryland forest of UFAM was the most diverse area, while the floodplain forest of Carú was the least. Additionally, the difference in diversity between UFAM and Carú was the highest among the comparisons. Thirty candidates for new yeast species were obtained, representing 36% of the species identified and totaling 101 isolates. Among them were species belonging to the clades Spathaspora, Scheffersomyces, and Sugiyamaella, which are recognized as genera with natural xylose-fermenting yeasts that are often studied for biotechnological and ecological purposes. The results of this work showed that rotting wood collected from the Amazonian rainforest is a tremendous source of diverse yeasts, including candidates for new species.
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Affiliation(s)
- Katharina O Barros
- Departmento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Laboratory of Genetics, J. F. Crow Institute for the Study of Evolution, Wisconsin Energy Institute, Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Flávia B M Alvarenga
- Departmento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Giulia Magni
- Departmento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Gisele F L Souza
- Departmento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Maxwel A Abegg
- Institute of Exact Sciences and Technology (ICET), Federal University of Amazonas (UFAM), Itacoatiara, Brazil
| | - Fernanda Palladino
- Departmento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sílvio S da Silva
- Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Lorena, Brazil
| | - Rita C L B Rodrigues
- Department of Biotechnology, Engineering School of Lorena, University of São Paulo, Lorena, Brazil
| | - Trey K Sato
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Chris Todd Hittinger
- DOE Great Lakes Bioenergy Research Center, University of Wisconsin-Madison, Madison, Wisconsin, USA.,Laboratory of Genetics, J. F. Crow Institute for the Study of Evolution, Wisconsin Energy Institute, Center for Genomic Science Innovation, University of Wisconsin-Madison, Madison, Wisconsin, USA
| | - Carlos A Rosa
- Departmento de Microbiologia, ICB, C.P. 486, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Galhardo JP, Piffer AP, Fiamenghi MB, Borelli G, da Silva DRM, Vasconcelos AA, Carazzolle MF, Pereira GAG, José J. Wide distribution of D-xylose dehydrogenase in yeasts reveals a new element in the D-xylose metabolism for bioethanol production. FEMS Yeast Res 2023; 23:foad003. [PMID: 36731871 DOI: 10.1093/femsyr/foad003] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 01/03/2023] [Accepted: 02/01/2023] [Indexed: 02/04/2023] Open
Abstract
D-xylose utilization by yeasts is an essential feature for improving second-generation ethanol production. However, industrial yeast strains are incapable of consuming D-xylose. Previous analyzes of D-xylose-consuming or fermenting yeast species reveal that the genomic features associated with this phenotype are complex and still not fully understood. Here we present a previously neglected yeast enzyme related to D-xylose metabolism, D-xylose dehydrogenase (XylDH), which is found in at least 105 yeast genomes. By analyzing the XylDH gene family, we brought evidence of gene evolution marked by purifying selection on codons and positive selection evidence in D-xylose-consuming and fermenting species, suggesting the importance of XylDH for D-xylose-related phenotypes in yeasts. Furthermore, although we found no putative metabolic pathway for XylDH in yeast genomes, namely the absence of three bacterial known pathways for this enzyme, we also provide its expression profile on D-xylose media following D-xylose reductase for two yeasts with publicly available transcriptomes. Based on these results, we suggest that XylDH plays an important role in D-xylose usage by yeasts, likely being involved in a cofactor regeneration system by reducing cofactor imbalance in the D-xylose reductase pathway.
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Affiliation(s)
- Juliana P Galhardo
- Laboratory of Genomics and bioEnergy (LGE), Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo, Brazil
| | - André P Piffer
- Laboratory of Genomics and bioEnergy (LGE), Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo, Brazil
| | - Mateus B Fiamenghi
- Laboratory of Genomics and bioEnergy (LGE), Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo, Brazil
| | - Guilherme Borelli
- Laboratory of Genomics and bioEnergy (LGE), Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo, Brazil
| | - Duguay R M da Silva
- Laboratory of Genomics and bioEnergy (LGE), Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo, Brazil
| | - Adrielle A Vasconcelos
- Laboratory of Genomics and bioEnergy (LGE), Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo, Brazil
| | - Marcelo F Carazzolle
- Laboratory of Genomics and bioEnergy (LGE), Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo, Brazil
| | - Gonçalo A G Pereira
- Laboratory of Genomics and bioEnergy (LGE), Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo, Brazil
| | - Juliana José
- Laboratory of Genomics and bioEnergy (LGE), Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, UNICAMP, Campinas, São Paulo, Brazil
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Integrated bioinformatics, modelling, and gene expression analysis of the putative pentose transporter from Candida tropicalis during xylose fermentation with and without glucose addition. Appl Microbiol Biotechnol 2022; 106:4587-4606. [PMID: 35708749 DOI: 10.1007/s00253-022-12005-x] [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: 07/21/2021] [Revised: 05/18/2022] [Accepted: 05/27/2022] [Indexed: 11/02/2022]
Abstract
The transport of substrates across the cell membrane plays an essential role in nutrient assimilation by yeasts. The establishment of an efficient microbial cell factory, based on the maximum use of available carbon sources, can generate new technologies that allow the full use of lignocellulosic constituents. These technologies are of interest because they could promote the formation of added-value products with economic feasibility. In silico analyses were performed to investigate gene sequences capable of encoding xylose transporter proteins in the Candida tropicalis genome. The current study identified 11 putative transport proteins that have not yet been functionally characterized. A phylogenetic tree highlighted the potential C. tropicalis xylose-transporter proteins CtXUT1, CtXUT4, CtSTL1, CtSTL2, and CtGXT2, which were homologous to previously characterized and reported xylose transporters. Their expression was quantified through real-time qPCR at defined times, determined through a kinetic analysis of the microbial growth curve in the absence/presence of glucose supplemented with xylose as the main carbon source. The results indicated different mRNA expression levels for each gene. CtXUT1 mRNA expression was only found in the absence of glucose in the medium. Maximum CtXUT1 expression was observed in intervals of the highest xylose consumption (21 to 36 h) that corresponded to consumption rates of 1.02 and 0.82 g/L/h in the formulated media, with xylose as the only carbon source and with glucose addition. These observations indicate that CtXUT1 is an important xylose transporter in C. tropicalis. KEY POINTS: • Putative xylose transporter proteins were identified in Candida tropicalis; • The glucose concentration in the cultivation medium plays a key role in xylose transporter regulation; • The transporter gene CtXUT1 has an important role in xylose consumption by Candida tropicalis.
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Franco-Duarte R, Čadež N, Rito T, Drumonde-Neves J, Dominguez YR, Pais C, Sousa MJ, Soares P. Whole-Genome Sequencing and Annotation of the Yeast Clavispora santaluciae Reveals Important Insights about Its Adaptation to the Vineyard Environment. J Fungi (Basel) 2022; 8:jof8010052. [PMID: 35049992 PMCID: PMC8781136 DOI: 10.3390/jof8010052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 11/16/2022] Open
Abstract
Clavispora santaluciae was recently described as a novel non-Saccharomyces yeast species, isolated from grapes of Azores vineyards, a Portuguese archipelago with particular environmental conditions, and from Italian grapes infected with Drosophila suzukii. In the present work, the genome of five Clavispora santaluciae strains was sequenced, assembled, and annotated for the first time, using robust pipelines, and a combination of both long- and short-read sequencing platforms. Genome comparisons revealed specific differences between strains of Clavispora santaluciae reflecting their isolation in two separate ecological niches—Azorean and Italian vineyards—as well as mechanisms of adaptation to the intricate and arduous environmental features of the geographical location from which they were isolated. In particular, relevant differences were detected in the number of coding genes (shared and unique) and transposable elements, the amount and diversity of non-coding RNAs, and the enzymatic potential of each strain through the analysis of their CAZyome. A comparative study was also conducted between the Clavispora santaluciae genome and those of the remaining species of the Metschnikowiaceae family. Our phylogenetic and genomic analysis, comprising 126 yeast strains (alignment of 2362 common proteins) allowed the establishment of a robust phylogram of Metschnikowiaceae and detailed incongruencies to be clarified in the future.
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Affiliation(s)
- Ricardo Franco-Duarte
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057 Braga, Portugal; (T.R.); (C.P.); (M.J.S.); (P.S.)
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, 4710-057 Braga, Portugal
- Correspondence: or
| | - Neža Čadež
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, 101, 1000 Ljubljana, Slovenia;
| | - Teresa Rito
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057 Braga, Portugal; (T.R.); (C.P.); (M.J.S.); (P.S.)
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, 4710-057 Braga, Portugal
| | - João Drumonde-Neves
- IITAA—Institute of Agricultural and Environmental Research and Technology, University of Azores, 9700-042 Angra do Heroísmo, Portugal;
| | | | - Célia Pais
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057 Braga, Portugal; (T.R.); (C.P.); (M.J.S.); (P.S.)
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, 4710-057 Braga, Portugal
| | - Maria João Sousa
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057 Braga, Portugal; (T.R.); (C.P.); (M.J.S.); (P.S.)
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, 4710-057 Braga, Portugal
| | - Pedro Soares
- CBMA, Centre of Molecular and Environmental Biology, Department of Biology, University of Minho, 4710-057 Braga, Portugal; (T.R.); (C.P.); (M.J.S.); (P.S.)
- Institute of Science and Innovation for Bio-Sustainability (IB-S), University of Minho, 4710-057 Braga, Portugal
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Oh SH, Schliep K, Isenhower A, Rodriguez-Bobadilla R, Vuong VM, Fields CJ, Hernandez AG, Hoyer LL. Using Genomics to Shape the Definition of the Agglutinin-Like Sequence ( ALS) Family in the Saccharomycetales. Front Cell Infect Microbiol 2021; 11:794529. [PMID: 34970511 PMCID: PMC8712946 DOI: 10.3389/fcimb.2021.794529] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 11/09/2021] [Indexed: 01/09/2023] Open
Abstract
The Candida albicans agglutinin-like sequence (ALS) family is studied because of its contribution to cell adhesion, fungal colonization, and polymicrobial biofilm formation. The goal of this work was to derive an accurate census and sequence for ALS genes in pathogenic yeasts and other closely related species, while probing the boundaries of the ALS family within the Order Saccharomycetales. Bioinformatic methods were combined with laboratory experimentation to characterize 47 novel ALS loci from 8 fungal species. AlphaFold predictions suggested the presence of a conserved N-terminal adhesive domain (NT-Als) structure in all Als proteins reported to date, as well as in S. cerevisiae alpha-agglutinin (Sag1). Lodderomyces elongisporus, Meyerozyma guilliermondii, and Scheffersomyces stipitis were notable because each species had genes with C. albicans ALS features, as well as at least one that encoded a Sag1-like protein. Detection of recombination events between the ALS family and gene families encoding other cell-surface proteins such as Iff/Hyr and Flo suggest widespread domain swapping with the potential to create cell-surface diversity among yeast species. Results from the analysis also revealed subtelomeric ALS genes, ALS pseudogenes, and the potential for yeast species to secrete their own soluble adhesion inhibitors. Information presented here supports the inclusion of SAG1 in the ALS family and yields many experimental hypotheses to pursue to further reveal the nature of the ALS family.
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Affiliation(s)
- Soon-Hwan Oh
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Klaus Schliep
- Institute of Environmental Biotechnology, Graz University of Technology, Graz, Austria
| | - Allyson Isenhower
- Department of Biology, Millikin University, Decatur, IL, United States
| | | | - Vien M. Vuong
- Department of Computer Science, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Christopher J. Fields
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Alvaro G. Hernandez
- Roy J. Carver Biotechnology Center, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Lois L. Hoyer
- Department of Pathobiology, College of Veterinary Medicine, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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10
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van Dijk M, Rugbjerg P, Nygård Y, Olsson L. RNA sequencing reveals metabolic and regulatory changes leading to more robust fermentation performance during short-term adaptation of Saccharomyces cerevisiae to lignocellulosic inhibitors. BIOTECHNOLOGY FOR BIOFUELS 2021; 14:201. [PMID: 34654441 PMCID: PMC8518171 DOI: 10.1186/s13068-021-02049-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 09/29/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND The limited tolerance of Saccharomyces cerevisiae to inhibitors is a major challenge in second-generation bioethanol production, and our understanding of the molecular mechanisms providing tolerance to inhibitor-rich lignocellulosic hydrolysates is incomplete. Short-term adaptation of the yeast in the presence of dilute hydrolysate can improve its robustness and productivity during subsequent fermentation. RESULTS We utilized RNA sequencing to investigate differential gene expression in the industrial yeast strain CR01 during short-term adaptation, mimicking industrial conditions for cell propagation. In this first transcriptomic study of short-term adaption of S. cerevisiae to lignocellulosic hydrolysate, we found that cultures respond by fine-tuned up- and down-regulation of a subset of general stress response genes. Furthermore, time-resolved RNA sequencing allowed for identification of genes that were differentially expressed at 2 or more sampling points, revealing the importance of oxidative stress response, thiamin and biotin biosynthesis. furan-aldehyde reductases and specific drug:H+ antiporters, as well as the down-regulation of certain transporter genes. CONCLUSIONS These findings provide a better understanding of the molecular mechanisms governing short-term adaptation of S. cerevisiae to lignocellulosic hydrolysate, and suggest new genetic targets for improving fermentation robustness.
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Affiliation(s)
- Marlous van Dijk
- Department of Biology and Bioengineering, Division of Industrial Biotechnology, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden
| | - Peter Rugbjerg
- Department of Biology and Bioengineering, Division of Industrial Biotechnology, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden
| | - Yvonne Nygård
- Department of Biology and Bioengineering, Division of Industrial Biotechnology, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden
| | - Lisbeth Olsson
- Department of Biology and Bioengineering, Division of Industrial Biotechnology, Chalmers University of Technology, Kemivägen 10, 412 96, Gothenburg, Sweden.
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11
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Zan X, Sun J, Chu L, Cui F, Huo S, Song Y, Koffas MAG. Improved glucose and xylose co-utilization by overexpression of xylose isomerase and/or xylulokinase genes in oleaginous fungus Mucor circinelloides. Appl Microbiol Biotechnol 2021; 105:5565-5575. [PMID: 34215904 DOI: 10.1007/s00253-021-11392-x] [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: 01/05/2021] [Revised: 04/28/2021] [Accepted: 06/07/2021] [Indexed: 12/17/2022]
Abstract
Most of the oleaginous microorganisms cannot assimilate xylose in the presence of glucose, which is the major bottleneck in the bioconversion of lignocellulose to biodiesel. Our present study revealed that overexpression of xylose isomerase (XI) gene xylA or xylulokinase (XK) gene xks1 increased the xylose consumption by 25 to 37% and enhanced the lipid content by 8 to 28% during co-fermentation of glucose and xylose. In xylA overexpressing strain Mc-XI, the activity of XI was 1.8-fold higher and the mRNA level of xylA at 24 h and 48 h was 11- and 13-fold higher than that of the control, respectively. In xks1 overexpressing strain Mc-XK, the mRNA level of xks1 was 4- to 11-fold of that of the control strain and the highest XK activity of 950 nmol min-1 mg-1 at 72 h which was 2-fold higher than that of the control. Additionally, expression of a translational fusion of xylA and xks1 further enhanced the xylose utilization rate by 45%. Our results indicated that overexpression of xylA and/or xks1 is a promising strategy to improve the xylose and glucose co-utilization, alleviate the glucose repression, and produce lipid from lignocellulosic biomass in the oleaginous fungus M. circinelloides. KEY POINTS: • Overexpressing xylA or xks1 increased the xylose consumption and the lipid content. • The xylose isomerase activity and the xylA mRNA level were enhanced in strain Mc-XI. • Co-expression of xylA and xks1 further enhanced the xylose utilization rate by 45%.
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Affiliation(s)
- Xinyi Zan
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China
| | - Jianing Sun
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China
| | - Linfang Chu
- School of Food Science and Technology, Jiang University, Wuxi, 214000, People's Republic of China
| | - Fengjie Cui
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China
| | - Shuhao Huo
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang, 212013, People's Republic of China
| | - Yuanda Song
- Colin Ratledge Center for Microbial Lipids, School of Agriculture Engineering and Food Science, Shandong University of Technology, Zibo, 255049, People's Republic of China.
| | - Mattheos A G Koffas
- Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, 12180, USA
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12
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Ruchala J, Sibirny AA. Pentose metabolism and conversion to biofuels and high-value chemicals in yeasts. FEMS Microbiol Rev 2020; 45:6034013. [PMID: 33316044 DOI: 10.1093/femsre/fuaa069] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 12/09/2020] [Indexed: 12/15/2022] Open
Abstract
Pentose sugars are widespread in nature and two of them, D-xylose and L-arabinose belong to the most abundant sugars being the second and third by abundance sugars in dry plant biomass (lignocellulose) and in general on planet. Therefore, it is not surprising that metabolism and bioconversion of these pentoses attract much attention. Several different pathways of D-xylose and L-arabinose catabolism in bacteria and yeasts are known. There are even more common and really ubiquitous though not so abundant pentoses, D-ribose and 2-deoxy-D-ribose, the constituents of all living cells. Thus, ribose metabolism is example of endogenous metabolism whereas metabolism of other pentoses, including xylose and L-arabinose, represents examples of the metabolism of foreign exogenous compounds which normally are not constituents of yeast cells. As a rule, pentose degradation by the wild-type strains of microorganisms does not lead to accumulation of high amounts of valuable substances; however, productive strains have been obtained by random selection and metabolic engineering. There are numerous reviews on xylose and (less) L-arabinose metabolism and conversion to high value substances; however, they mostly are devoted to bacteria or the yeast Saccharomyces cerevisiae. This review is devoted to reviewing pentose metabolism and bioconversion mostly in non-conventional yeasts, which naturally metabolize xylose. Pentose metabolism in the recombinant strains of S. cerevisiae is also considered for comparison. The available data on ribose, xylose, L-arabinose transport, metabolism, regulation of these processes, interaction with glucose catabolism and construction of the productive strains of high-value chemicals or pentose (ribose) itself are described. In addition, genome studies of the natural xylose metabolizing yeasts and available tools for their molecular research are reviewed. Metabolism of other pentoses (2-deoxyribose, D-arabinose, lyxose) is briefly reviewed.
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Affiliation(s)
- Justyna Ruchala
- Department of Microbiology and Molecular Genetics, University of Rzeszow, Zelwerowicza 4, Rzeszow 35-601, Poland.,Department of Molecular Genetics and Biotechnology, Institute of Cell Biology NAS of Ukraine, Drahomanov Street, 14/16, Lviv 79005, Ukraine
| | - Andriy A Sibirny
- Department of Microbiology and Molecular Genetics, University of Rzeszow, Zelwerowicza 4, Rzeszow 35-601, Poland.,Department of Molecular Genetics and Biotechnology, Institute of Cell Biology NAS of Ukraine, Drahomanov Street, 14/16, Lviv 79005, Ukraine
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Abstract
Nowadays, the transport sector is one of the main sources of greenhouse gas (GHG) emissions and air pollution in cities. The use of renewable energies is therefore imperative to improve the environmental sustainability of this sector. In this regard, biofuels play an important role as they can be blended directly with fossil fuels and used in traditional vehicles’ engines. Bioethanol is the most used biofuel worldwide and can replace gasoline or form different gasoline-ethanol blends. Additionally, it is an important building block to obtain different high added-value compounds (e.g., acetaldehyde, ethylene, 1,3-butadiene, ethyl acetate). Today, bioethanol is mainly produced from food crops (first-generation (1G) biofuels), and a transition to the production of the so-called advanced ethanol (obtained from lignocellulosic feedstocks, non-food crops, or industrial waste and residue streams) is needed to meet sustainability criteria and to have a better GHG balance. This work gives an overview of the current production, use, and regulation rules of bioethanol as a fuel, as well as the advanced processes and the co-products that can be produced together with bioethanol in a biorefinery context. Special attention is given to the opportunities for making a sustainable transition from bioethanol 1G to advanced bioethanol.
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Candida intermedia CBS 141442: A Novel Glucose/Xylose Co-Fermenting Isolate for Lignocellulosic Bioethanol Production. ENERGIES 2020. [DOI: 10.3390/en13205363] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The present study describes the isolation of the novel strain Candida intermedia CBS 141442 and investigates the potential of this microorganism for the conversion of lignocellulosic streams. Different C. intermedia clones were isolated during an adaptive laboratory evolution experiment under the selection pressure of lignocellulosic hydrolysate and in strong competition with industrial, xylose-fermenting Saccharomyces cerevisiae cells. Isolates showed different but stable colony and cell morphologies when growing in a solid agar medium (smooth, intermediate and complex morphology) and liquid medium (unicellular, aggregates and pseudohyphal morphology). Clones of the same morphology showed similar fermentation patterns, and the C. intermedia clone I5 (CBS 141442) was selected for further testing due to its superior capacity for xylose consumption (90% of the initial xylose concentration within 72 h) and the highest ethanol yields (0.25 ± 0.02 g ethanol/g sugars consumed). Compared to the well-known yeast Scheffersomyces stipitis, the selected strain showed slightly higher tolerance to the lignocellulosic-derived inhibitors when fermenting a wheat straw hydrolysate. Furthermore, its higher glucose consumption rates (compared to S. stipitis) and its capacity for glucose and xylose co-fermentation makes C. intermedia CBS 141442 an attractive microorganism for the conversion of lignocellulosic substrates, as demonstrated in simultaneous saccharification and fermentation processes.
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