Genes from increase salt tolerance in W303

The main focus in development of yeast cell factories has generally been on establishing optimal activity of heterologous pathways and further metabolic engineering of the host strain to maximize product yield and titer. Adequate stress tolerance of the host strain has turned out to be another major challenge for obtaining economically viable performance in industrial production. Although general robustness is a universal requirement for industrial microorganisms, production of novel compounds using artificial metabolic pathways presents additional challenges. Many of the bio-based compounds desirable for production by cell factories are highly toxic to the host cells in the titers required for economic viability. Artificial metabolic pathways also turn out to be much more sensitive to stress factors than endogenous pathways, likely because regulation of the latter has been optimized in evolution in myriads of environmental conditions. We discuss different environmental and metabolic stress factors with high relevance for industrial utilization of yeast cell factories and the experimental approaches used to engineer higher stress tolerance. Improving stress tolerance in a predictable manner in yeast cell factories should facilitate their widespread utilization in the bio-based economy and extend the range of products successfully produced in large scale in a sustainable and economically profitable way.

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“…In this regard, an S. cerevisiae lab strain displayed improved salt tolerance by expression of genes from D. hansenii (Prista et al. 2002 ).…”

Section: Industrial Use Of Alternative Stress-tolerant Non-conventionmentioning

confidence: 99%

Engineering tolerance to industrially relevant stress factors in yeast cell factories

Deparis

Claes

Foulquié-Moreno

et al. 2017

FEMS Yeast Research

145

129

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“…Although plants may have unique adaptive mechanisms to accommodate various stresses, the basic cellular stress response (CSR) mechanism, which is activated in response to stress, is similar in prokaryotes, lower plants, and eukaryotes [ 4 , 10 ]. Accordingly, stress-resistance genes of halotolerant fungal species have the potential to improve the stress tolerance of microorganisms and plants [ 11 – 14 ].…”

Section: Introductionmentioning

confidence: 99%

Isolation of Salt Stress-Related Genes fromAspergillus glaucusCCHA by Random Overexpression inEscherichia coli

Fang

Han

Xie

et al. 2014

The Scientific World Journal

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The halotolerant fungus Aspergillus glaucus CCHA was isolated from the surface of wild vegetation around a saltern with the salinity range being 0–31%. Here, a full-length cDNA library of A. glaucus under salt stress was constructed to identify genes related to salt tolerance, and one hundred clones were randomly selected for sequencing and bioinformatics analysis. Among these, 82 putative sequences were functionally annotated as being involved in signal transduction, osmolyte synthesis and transport, or regulation of transcription. Subsequently, the cDNA library was transformed into E. coli cells to screen for putative salt stress-related clones. Five putative positive clones were obtained from E. coli cells grown on LB agar containing 1 M NaCl, on which they showed rapid growth compared to the empty vector control line. Analysis of transgenic Arabidopsis thaliana lines overexpressing CCHA-2142 demonstrated that the gene conferred increased salt tolerance to plants as well by protecting the cellular membranes, suppressing the inhibition of chlorophyll biosynthesis. These results highlight the utility of this A. glaucus cDNA library as a tool for isolating and characterizing genes related to salt tolerance. Furthermore, the identified genes can be used for the study of the underlying biology of halotolerance.

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Heterologous Expression Implicates a GATA Factor in Regulation of Nitrogen Metabolic Genes and Ion Homeostasis in the Halotolerant Yeast Debaryomyces hansenii

et al. 2006

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The yeast Debaryomyces hansenii has a remarkable capacity to proliferate in salty and alkaline environments such as seawater. A screen for D. hansenii genes able to confer increased tolerance to high pH when overexpressed in Saccharomyces cerevisiae yielded a single gene, named here DhGZF3, encoding a putative negative GATA transcription factor related to S. cerevisiae Dal80 and Gzf3. Overexpression of this gene in wild-type S. cerevisiae increased caffeine and rapamycin tolerance, blocked growth in low glucose concentrations and nonfermentable carbon sources, and resulted in lithium-and sodium-sensitive cells. Sensitivity to salt could be attributed to a reduced cation efflux, most likely because of a decrease in expression of the ENA1 Na ؉ -ATPase gene. Overexpression of DhGZF3 did not affect cell growth in a gat1 mutant but was lethal in the absence of Gln3. These are positive factors that oppose both Gzf3 and Dal80. Genome-wide transcriptional profiling of wild-type cells overexpressing DhGZF3 shows decreased expression of a number of genes that are usually induced in poor nitrogen sources. In addition, the entire pathway leading to Lys biosynthesis was repressed, probably as a result of a decrease in the expression of the specific Lys14 transcription factor. In conclusion, our results demonstrate that DhGzf3 can play a role as a negative GATA transcription factor when expressed in S. cerevisiae and that it most probably represents the only member of this family in D. hansenii. These findings also point to the GATA transcription factors as relevant elements for alkaline-pH tolerance.Adaptation to conditions of high-salt stress is a biological process of the utmost importance in agriculture and biotechnology due to the increased salinization of irrigated lands. Debaryomyces hansenii is an ascomycetous salt-and high-pHtolerant yeast found in seawaters and salty food. This yeast is becoming a model for the study of salt tolerance mechanisms in eukaryotic cells (37), and this research will be boosted by the recent release of its complete genomic sequence (21). Although the halotolerant characteristics of this organism were defined a long time ago (33,34,36), the molecular basis for the halotolerant phenotype is still obscure. D. hansenii encodes orthologs to most components that have been found to be relevant for salt tolerance in other fungi, particularly in the model yeast Saccharomyces cerevisiae. Examples are the DhHOG1 mitogen-activated protein kinase, the DhHAL2 nucleotidase, and the DhENA1 and DhENA2 sodium ATPase pumps (2, 4, 5). In most cases, these gene products have proven to be functional for complementing the equivalent S. cerevisiae mutants, although they did not confer a particularly strong salt-tolerant phenotype even when overexpressed. However, the fact that D. hansenii is not an easily tractable organism from a genetic point of view and the lack of molecular tools to approach its study have been important disadvantages in attempts to define the basis for its unusual salt tolerance.The natural ...

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Genes from increase salt tolerance in W303

Cited by 3 publications

References 0 publications

Engineering tolerance to industrially relevant stress factors in yeast cell factories

Engineering tolerance to industrially relevant stress factors in yeast cell factories

Isolation of Salt Stress-Related Genes fromAspergillus glaucusCCHA by Random Overexpression inEscherichia coli

Heterologous Expression Implicates a GATA Factor in Regulation of Nitrogen Metabolic Genes and Ion Homeostasis in the Halotolerant Yeast Debaryomyces hansenii

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