An analysis of the transcriptome of Debaryomyces hansenii acclimated to sodium chloride induced osmotic stress

Abstract

Debaryomyces hansenii is one of the most halotolerant yeast species uncovered thus far. The recent exploration of its genome in the Genolevures project and its extremophilic characteristics make D. hansenii a potential model organism to study salt based stress response. Indeed, the genome sequence of two strains (CBS767 and MTCC234) have been determined, providing insight into the evolution of various yeast species. We have isolated a new strain of D. hansenii from salt brine at a cheese factory in Denmark. In this study, we assessed the response of this strain to salt stress through growth assays, fermentation capability assays and exome analysis. In this study the effect of NaCl on the fermentation abilities and the transcriptome of D. hansenii acclimated to media devoid of any NaCl and media with 1M, 2M, 3M NaCl was assessed using RNA-Seq. Fermentation experiments showed an increase in ethanol productivity with an increase in NaCl until a threshold was reached. The sequencing results revealed many statistically significant (P

Date of Award	May 2015
Original language	American English
Supervisor	Mette H. Thomsen (Supervisor)