Draft Genome Sequence of an Acid-Tolerant Yeast, Candida zemplinina NP2, a Potential Producer of Organic Acids.

Here, we report the draft genome sequence of the acid-tolerant yeast Candida zemplinina NP2, which was isolated from peach peels. This genome sequence will aid in the understanding of the organism's physiological properties as a potential producer of organic acids in acidic environments.

GENOME ANNOUNCEMENT

Candida zemplinina is synonymously known as Starmerella bacillaris and is an acidophilic yeast species frequently isolated from fruit sources and wine environments (1). Owing to its osmotolerant, psychrotolerant, and acid-tolerant properties (2, 3), C. zemplinina has been applied in mixed fermentation with Saccharomyces cerevisiae to reduce acetic acid byproducts generated by S. cerevisiae in botrytized wine fermentation (4). Recently, organic acids, such as succinic acid, 3-hydroxypropionic acid, and lactic acid, have become increasingly attractive as important platform chemicals in biorefining applications (5). With an ability to grow at a low pH (pH < 2), C. zemplinina is explored for its potential as the producer of a variety of organic acids. Here, we report the draft genome sequence of C. zemplinina NP2, an acid-tolerant yeast isolated from peach peels, in order to obtain further insight into the acid-tolerant properties of NP2 in fermentation of a variety of organic acids under acidic conditions.

Genome sequencing of C. zemplinina NP2 was performed by the Illumina HiSeq 2500 platform using paired-end libraries at the Core Facility Management Center in the Korea Research Institute of Bioscience and Biotechnology (KRIBB). We obtained 15.6 million paired-end reads, with 78.9-fold coverage. Low-quality (Q < 30) reads were identified and eliminated by the HTQC program (6). De novo assembly of the filtered reads was performed using Velvet, version 1.2.10, and VelvetOptimiser, version 2.2.5 (7). The final assembly was 9,311,634 bp, with 117 scaffolds and 145 gaps. The G+C content was 39.46%, and 131 tRNA-coding sequences, including 2 tRNA-like pseudogenes, were identified by tRNAscan-SE (8). The N50 value was 481,187 bp, and the length of the longest contig was 1,363,694 bp. Gene prediction of the genome sequence was performed using AUGUSTUS with a training set of Candida albicans (9). In total, 3,741 protein-coding genes were predicted in the draft genome, and 3,285 of these candidates were functionally characterized using an InterProScan search against the InterPro protein signature databases (10).

Accession number(s).

The nucleotide sequence has been deposited in GenBank under the accession number NQLE00000000.