Comparative genomics among Brettanomyces bruxellensis strains isolated from wine and beer

Background: The yeast Brettanomyces bruxellensis plays an intriguing dual role in beverage production, where it is sometimes regarded as a contaminant, and sometimes as a beneficial contributor to the fermentation of specialty beers. Whereas the genome of B. bruxellensis wine strains has become recently available, no genome sequence is available yet for a strain from an industry where its presence is desirable. Objective: Here, we report the comparison of the genome of a beneficial strain isolated from beer (VIBX9085) and that of a wine spoilage strain (AWRI1499), emphasizing on unique and differential genes, single nucleotide polymorphisms (SNPs), and small insertions and deletions (InDels). Methods: The VIBX9085 genome was sequenced using Illumina technology. Contigs were de novo assembled using SOAPdenovo, and scaffolded with SSPACE. Saccharomyces cerevisiae gene models were used as reference for the prediction of coding sequences. Consensus SNPs and InDels were called using SAMtools and GATK with AWRI1499 as reference. GO Slim terms obtained with Blast2GO were ranked by overall average variations to find functional differences. Unique genes were interpreted using gene ontology hierarchies. Conclusion: The genome of the beer strain consists of 4,073 genes homologous to AWRI1499. 936 of the predicted genes were found to be unique to the VIBX9085. Likewise, 110 genes in the AWRI1499 have no homology in the beer strain. Compared to the wine strain genome, the beer strain has 3.32 SNPs/kbp and 0.91 InDels/kbp. Go Slim terms are yet to be analysed (but will be presented in the poster).status: publishe