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Stress Tolerance Variations in Saccharomyces cerevisiae Strains from Diverse Ecological Sources and Geographical Locations.

Zheng YL, Wang SA - PLoS ONE (2015)

Bottom Line: The results showed that the isolates from human-associated environments overall presented a higher level of stress tolerance compared with those from forests spared anthropogenic influences.Statistical analyses indicated that the variations of stress tolerance were significantly correlated with both ecological sources and geographical locations of the strains.This study provides guidelines for selection of robust S. cerevisiae strains for bioethanol production from nature.

View Article: PubMed Central - PubMed

Affiliation: College of Mathematics and Systems Science, Shandong University of Science and Technology, Qingdao, 266590, China.

ABSTRACT
The budding yeast Saccharomyces cerevisiae is a platform organism for bioethanol production from various feedstocks and robust strains are desirable for efficient fermentation because yeast cells inevitably encounter stressors during the process. Recently, diverse S. cerevisiae lineages were identified, which provided novel resources for understanding stress tolerance variations and related shaping factors in the yeast. This study characterized the tolerance of diverse S. cerevisiae strains to the stressors of high ethanol concentrations, temperature shocks, and osmotic stress. The results showed that the isolates from human-associated environments overall presented a higher level of stress tolerance compared with those from forests spared anthropogenic influences. Statistical analyses indicated that the variations of stress tolerance were significantly correlated with both ecological sources and geographical locations of the strains. This study provides guidelines for selection of robust S. cerevisiae strains for bioethanol production from nature.

No MeSH data available.


Related in: MedlinePlus

Boxplots depicting stress tolerance variations between the ecological groups.(a) ethanol stress; (b) heat stress; (c) osmotic stress. The number of strains in the Orchard, Wild, and Industrial group was 37, 34, and 12, respectively. The box contains the middle 50% of the data. Horizontal line inside the box: median; Upper boundary of whisker: largest observed value that is not an outlier; Lower boundary of whisker: smallest observed value that is not outlier. ○ = values >1.5 box-lengths from the box but not extremes (outliers). * Values >3 box-lengths from the box (extremes).
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pone.0133889.g004: Boxplots depicting stress tolerance variations between the ecological groups.(a) ethanol stress; (b) heat stress; (c) osmotic stress. The number of strains in the Orchard, Wild, and Industrial group was 37, 34, and 12, respectively. The box contains the middle 50% of the data. Horizontal line inside the box: median; Upper boundary of whisker: largest observed value that is not an outlier; Lower boundary of whisker: smallest observed value that is not outlier. ○ = values >1.5 box-lengths from the box but not extremes (outliers). * Values >3 box-lengths from the box (extremes).

Mentions: To evaluate the impact of ecological source on stress tolerance variations of S. cerevisiae strains, the 83 strains were categorized into three groups based on ecological sources, namely Orchard, Wild, and Industrial (Table 1). Stress tolerance was compared between the three groups. Significantly higher levels of tolerance to ethanol (ANOVA, at the 0.05 level) and heat stress (Kruskal-Wallis Test, at the 0.05 level) presented in the Orchard group compared with the Wild and Industrial groups, indicating the influence of ecological source on phenotypic variations of S. cerevisiae strains (Fig 4A and 4B). Tolerance to osmotic stress was comparable among the three groups (Fig 4C). Unexpectedly, the Industrial group did not overall generate a high stress tolerance level. This is because the Clade 3 and mosaic strains in the Industrial group represented stress sensitivity, though the Sake and Wine/European strains from distilled spirit in the Industrial group showed tolerance to ethanol and heat stress (Table 1 and Fig 2).


Stress Tolerance Variations in Saccharomyces cerevisiae Strains from Diverse Ecological Sources and Geographical Locations.

Zheng YL, Wang SA - PLoS ONE (2015)

Boxplots depicting stress tolerance variations between the ecological groups.(a) ethanol stress; (b) heat stress; (c) osmotic stress. The number of strains in the Orchard, Wild, and Industrial group was 37, 34, and 12, respectively. The box contains the middle 50% of the data. Horizontal line inside the box: median; Upper boundary of whisker: largest observed value that is not an outlier; Lower boundary of whisker: smallest observed value that is not outlier. ○ = values >1.5 box-lengths from the box but not extremes (outliers). * Values >3 box-lengths from the box (extremes).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526645&req=5

pone.0133889.g004: Boxplots depicting stress tolerance variations between the ecological groups.(a) ethanol stress; (b) heat stress; (c) osmotic stress. The number of strains in the Orchard, Wild, and Industrial group was 37, 34, and 12, respectively. The box contains the middle 50% of the data. Horizontal line inside the box: median; Upper boundary of whisker: largest observed value that is not an outlier; Lower boundary of whisker: smallest observed value that is not outlier. ○ = values >1.5 box-lengths from the box but not extremes (outliers). * Values >3 box-lengths from the box (extremes).
Mentions: To evaluate the impact of ecological source on stress tolerance variations of S. cerevisiae strains, the 83 strains were categorized into three groups based on ecological sources, namely Orchard, Wild, and Industrial (Table 1). Stress tolerance was compared between the three groups. Significantly higher levels of tolerance to ethanol (ANOVA, at the 0.05 level) and heat stress (Kruskal-Wallis Test, at the 0.05 level) presented in the Orchard group compared with the Wild and Industrial groups, indicating the influence of ecological source on phenotypic variations of S. cerevisiae strains (Fig 4A and 4B). Tolerance to osmotic stress was comparable among the three groups (Fig 4C). Unexpectedly, the Industrial group did not overall generate a high stress tolerance level. This is because the Clade 3 and mosaic strains in the Industrial group represented stress sensitivity, though the Sake and Wine/European strains from distilled spirit in the Industrial group showed tolerance to ethanol and heat stress (Table 1 and Fig 2).

Bottom Line: The results showed that the isolates from human-associated environments overall presented a higher level of stress tolerance compared with those from forests spared anthropogenic influences.Statistical analyses indicated that the variations of stress tolerance were significantly correlated with both ecological sources and geographical locations of the strains.This study provides guidelines for selection of robust S. cerevisiae strains for bioethanol production from nature.

View Article: PubMed Central - PubMed

Affiliation: College of Mathematics and Systems Science, Shandong University of Science and Technology, Qingdao, 266590, China.

ABSTRACT
The budding yeast Saccharomyces cerevisiae is a platform organism for bioethanol production from various feedstocks and robust strains are desirable for efficient fermentation because yeast cells inevitably encounter stressors during the process. Recently, diverse S. cerevisiae lineages were identified, which provided novel resources for understanding stress tolerance variations and related shaping factors in the yeast. This study characterized the tolerance of diverse S. cerevisiae strains to the stressors of high ethanol concentrations, temperature shocks, and osmotic stress. The results showed that the isolates from human-associated environments overall presented a higher level of stress tolerance compared with those from forests spared anthropogenic influences. Statistical analyses indicated that the variations of stress tolerance were significantly correlated with both ecological sources and geographical locations of the strains. This study provides guidelines for selection of robust S. cerevisiae strains for bioethanol production from nature.

No MeSH data available.


Related in: MedlinePlus