De novo genome sequencing of the yeast Candida intermedia

Conference poster, 2015

The urgency to reduce carbon emissions and to lower our dependence on oil makes it necessary to strive towards a more sustainable, bio-based economy where energy, chemicals, materials and food are produced from renewable resources. Lignocellulosic biomass constitutes a great source of raw material for such a future bio-based economy since it is widely available, relatively inexpensive and do not compete with food and feed production. Saccharomyces cerevisiae is commonly used for bioethanol production and displays excellent glucose fermenting skills, but metabolic engineering is needed to allow consumption and fermentation of xylose (the second to glucose most prevalent sugar in lignocellulose). As an alternative to S. cerevisiae, microorganisms that naturally ferment xylose can be used. An unexpected discovery in our lab allowed us to isolate a clone of the non-conventional, xylose fermenting yeast species Candida intermedia. The aim of this project is to sequence the genome of C. intermedia as well as to develop a molecular toolbox to allow genetic manipulations of this yeast. PacBio sequencing and de novo assembly of the genome revealed a haploid yeast with a genome size of 13.2 Mb and a total of 5216 genes spread over seven chromosomes. Future activities include identification of genes involved in uptake and fermentation of sugars derived from lignocellulosic biomass, and subsequent deletion/overexpression of interesting candidate genes to improve the fermentation capacity of the yeast.