Genome sequencing and analysis of <Emphasis Type="Italic">Kloeckera apiculata</Emphasis> strain 34-9, a biocontrol agent against postharvest pathogens in citrus

Kloeckera apiculata, as the anamorphic state of Hanseniaspora uvarum from the Ascomycota phylum, plays an important role in the inhibition of fungal diseases in plants and spontaneous wine fermentation. This study was performed to sequence and analyze the whole genome of K. apiculata strain 34-9; This analysis provides further genomic features and assists functional research. The complete genome was determined using an Illumina HiSeq 2000 system applying paired-end and mate-pair methods to construct four reads libraries. The data assembly of all the reads resulted in a total genome size of 8.1 Mb, including 106 contigs, which were assembled into 41 scaffolds with a 31.95 % G+C content and a 234X sequence coverage. The performance of the gene prediction and functional annotation revealed that 2724 of 3786 protein-coding genes matched the KOG database, and 1127 genes were classified into GO categories. Further genome features analyses found 1066 microsatellite sites, 71 tRNAs, 3 rRNAs and 3 microRNAs in the genomic DNA. A prediction of the metabolic pathways identified potentially crucial genes for explaining the phenylalanine pathway involved in biocontrol. Comparisons with the typical yeasts Lachancea thermotolerans, Kluyveromyces lactis and Saccharomyces cerevisiae revealed the particularity and difference of K. apiculata strain 34-9. The genome alignments among Hanseniaspora vineae T02/19AF, K. apiculata DSM 2768 and 34-9 indicated numerous homologous regions distributed over the genomes between strain DSM2768 and 34-9. A SSR analysis identified that mono- and tri- nucleotide repeat types were more abundant in all six types, likely affecting the evolution of K. apiculata.