Functional genome annotation and transcriptome analysis of Pseudozyma hubeiensis BOT-O, an oleaginous yeast that utilizes glucose and xylose at equal rates
Journal article, 2023

Pseudozyma hubeiensis is a basidiomycete yeast that has the highly desirable traits for lignocellulose valorisation of being equally efficient at utilization of glucose and xylose, and capable of their co-utilization. The species has previously mainly been studied for its capacity to produce secreted biosurfactants in the form of mannosylerythritol lipids, but it is also an oleaginous species capable of accumulating high levels of triacylglycerol storage lipids during nutrient starvation. In this study, we aimed to further characterize the oleaginous nature of P. hubeiensis by evaluating metabolism and gene expression responses during storage lipid formation conditions with glucose or xylose as a carbon source. The genome of the recently isolated P. hubeiensis BOT-O strain was sequenced using MinION long-read sequencing and resulted in the most contiguous P. hubeiensis assembly to date with 18.95 Mb in 31 contigs. Using transcriptome data as experimental support, we generated the first mRNA-supported P. hubeiensis genome annotation and identified 6540 genes. 80% of the predicted genes were assigned functional annotations based on protein homology to other yeasts. Based on the annotation, key metabolic pathways in BOT-O were reconstructed, including pathways for storage lipids, mannosylerythritol lipids and xylose assimilation. BOT-O was confirmed to consume glucose and xylose at equal rates, but during mixed glucose-xylose cultivation glucose was found to be taken up faster. Differential expression analysis revealed that only a total of 122 genes were significantly differentially expressed at a cut-off of |log2 fold change| ≥ 2 when comparing cultivation on xylose with glucose, during exponential growth and during nitrogen-starvation. Of these 122 genes, a core-set of 24 genes was identified that were differentially expressed at all time points. Nitrogen-starvation resulted in a larger transcriptional effect, with a total of 1179 genes with significant expression changes at the designated fold change cut-off compared with exponential growth on either glucose or xylose.

Lipid accumulation

Genome sequencing

Nitrogen-starvation

Pseudozyma hubeiensis

Differential gene expression

RNAseq

Author

Friederike Mierke

Chalmers, Life Sciences, Food and Nutrition Science

Daniel P. Brink

Lund University

Joakim Norbeck

Utbildningsstöd

Verena Siewers

Chalmers, Life Sciences, Systems and Synthetic Biology

Thomas Andlid

Undergraduate Education Physics, Chemistry and Biological Engineering along with Mathematics and Engineering Preparatory Year

Fungal Genetics and Biology

1087-1845 (ISSN) 1096-0937 (eISSN)

Vol. 166 103783

Biodegradable non-fossil plastics as food packaging material - Novel strategy for PHB production by modification of oil accumulating yeast

Formas (2018-01875), 2018-12-01 -- 2021-11-30.

Subject Categories

Microbiology

Bioinformatics and Systems Biology

Genetics

DOI

10.1016/j.fgb.2023.103783

PubMed

36870442

More information

Latest update

3/24/2023