A glimpse of potential transposable element impact on adaptation of the industrial yeast Saccharomyces cerevisiae

Authors: Liu, Zonglin; HUANG, XIAOQIU - Iowa State University

Submitted to: Federation of European Microbiological Societies Yeast Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/23/2020
Publication Date: 8/11/2020
Citation: Liu, Z., Huang, X. 2020. A glimpse of potential transposable element impact on adaptation of the industrial yeast Saccharomyces cerevisiae. Federation of European Microbiological Societies Yeast Research. 20(6). Article foaa043. https://doi.org/10.1093/femsyr/foaa043.
DOI: https://doi.org/10.1093/femsyr/foaa043

Interpretive Summary: USDA researchers have developed a more robust yeast strain suitable for converting biomass to ethanol through adaptation. It can survive the toxic chemicals and convert them into less toxic compounds while producing ethanol. Several mechanisms and tolerance genes responsible for the yeast tolerance were previously identified. However, a significant large group of transposable element genes were overlooked due to limited knowledge and deficiencies of early analytical technologies. This research presents the first evidence of highly activated expressions of these genes in response to the toxic challenge compared with its wild type control over time. Specific chromosomes harboring a high number of such genes were also identified. Future research directions were suggested based on new findings of this study. Outcomes of this research provide insight underlying mechanisms of yeast tolerance and adaptation. It will be of interest to industrial microbiologists working to develop better yeast and more generally to agricultural refiners with interest in fermentation type of processes.

Technical Abstract: The adapted industrial yeast strain Saccharomyces cerevisiae NRRL Y-50049 is able to in situ detoxify major toxic aldehyde compounds derived from lignocellulosic biomass conversion to sugars while producing ethanol. Pathway-based studies on its mechanisms of tolerance have been previously reported, however, little is known about transposable element involvement in its adaptation to these inhibitory compounds. This work presents a comparative transcription expression analysis in response to a toxic treatment between Y-50049 and its progenitor, industrial type strain NRRL Y-12632, using a time-course study. The distinctive differential expressions of at least 77 TEs from Y-50049 observed in this study brought awareness of the potential roles of TEs in adaptation of tolerance to the toxic chemicals. Chromosome IV harbored at least 21 differentially expressed TEs, including 9 pairs of closely related co-transcribed genes and other significant TEs, which may facilitate an initial effort for continued investigations.