Genomic and transcriptomic analysis of Candida intermedia reveals the genetic determinants for its xylose-converting capacity
Journal article, 2020

Background An economically viable production of biofuels and biochemicals from lignocellulose requires microorganisms that can readily convert both the cellulosic and hemicellulosic fractions into product. The yeast Candida intermedia displays a high capacity for uptake and conversion of several lignocellulosic sugars including the abundant pentose d-xylose, an underutilized carbon source since most industrially relevant microorganisms cannot naturally ferment it. Thus, C. intermedia constitutes an important source of knowledge and genetic information that could be transferred to industrial microorganisms such as Saccharomyces cerevisiae to improve their capacity to ferment lignocellulose-derived xylose. Results To understand the genetic determinants that underlie the metabolic properties of C. intermedia, we sequenced the genomes of both the in-house-isolated strain CBS 141442 and the reference strain PYCC 4715. De novo genome assembly and subsequent analysis revealed C. intermedia to be a haploid species belonging to the CTG clade of ascomycetous yeasts. The two strains have highly similar genome sizes and number of protein-encoding genes, but they differ on the chromosomal level due to numerous translocations of large and small genomic segments. The transcriptional profiles for CBS 141442 grown in medium with either high or low concentrations of glucose and xylose were determined through RNA-sequencing analysis, revealing distinct clusters of co-regulated genes in response to different specific growth rates, carbon sources and osmotic stress. Analysis of the genomic and transcriptomic data also identified multiple xylose reductases, one of which displayed dual NADH/NADPH co-factor specificity that likely plays an important role for co-factor recycling during xylose fermentation. Conclusions In the present study, we performed the first genomic and transcriptomic analysis of C. intermedia and identified several novel genes for conversion of xylose. Together the results provide insights into the mechanisms underlying saccharide utilization in C. intermedia and reveal potential target genes to aid in xylose fermentation in S. cerevisiae.

Xylose

Complete genome sequence

aldose reductase

Biofuels

NADH-preferring xylose reductase

RNA-Seq

Pentose metabolism

Xylose utilization

Saccharomyces cerevisiae

Author

Cecilia Geijer

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Fábio Luis Da Silva Faria Oliveira

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

David Moreno

Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (Ciemat)

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Simon Stenberg

University of Gothenburg

Scott Mazurkewich

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Lisbeth Olsson

Chalmers, Biology and Biological Engineering, Industrial Biotechnology

Biotechnology for Biofuels

1754-6834 (eISSN)

Vol. 13 1 48

Subject Categories

Microbiology

Bioinformatics and Systems Biology

Genetics

DOI

10.1186/s13068-020-1663-9

PubMed

32190113

More information

Latest update

5/18/2020