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Variation in pH gradients and FLO11 expression in mat biofilms from environmental isolates of the yeast Saccharomyces cerevisiae
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  • Amy Forehand,
  • Dulguun Myagmarsuren,
  • Ziyan Chen,
  • Helen Murphy
Amy Forehand
William & Mary

Corresponding Author:[email protected]

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Dulguun Myagmarsuren
William & Mary
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Ziyan Chen
William & Mary
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Helen Murphy
William & Mary
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Saccharomyces cerevisiae produces a multicellular phenotype, known as a mat, on a semi-solid medium. This biofilm phenotype was first described in the lab strain 1278b and has been analyzed mostly in this same background. Yeast cells form a mat by spreading across the medium and adhering to each other and the surface, in part through the variegated expression of the cell adhesin, FLO11. This process creates a characteristic floral pattern and generates pH and glucose gradients outward from the center of the mat. Mats are encapsulated in a liquid which may aid in surface spreading and diffusion. Here, we examine thirteen environmental isolates that vary visually in the phenotype. We predicted that mat properties were universal and increased morphological complexity would be associated with more extreme trait values. Our results showed that pH varied significantly among strains, but was not correlated to mat complexity. Only two isolates generated significant liquid boundaries and neither produced visually complex mats. In five isolates, we tracked the initiation of FLO11 using GFP under the control of the endogenous promoter. Strains varied in when and how much GFP was detected, with increased signal associated with increased morphological complexity. Generally, the signal was strongest in the center of the mat and absent at the expanding edge. Our results show that traits discovered in one background vary and exist independently of mat complexity in natural isolates. The environment may favor different sets of traits, which could have implications for how this yeast adapts to its many ecological niches.
02 Feb 2022Submitted to MicrobiologyOpen
04 Feb 2022Submission Checks Completed
04 Feb 2022Assigned to Editor
08 Feb 2022Reviewer(s) Assigned
21 Feb 2022Review(s) Completed, Editorial Evaluation Pending
21 Feb 2022Editorial Decision: Revise Minor
02 Mar 20221st Revision Received
03 Mar 2022Submission Checks Completed
03 Mar 2022Assigned to Editor
05 Mar 2022Review(s) Completed, Editorial Evaluation Pending
10 Mar 2022Editorial Decision: Accept