Transcriptional analysis of Lactobacillus delbrueckii subsp. delbrueckii during soy juice fermentation.

The objective of this study was to decipher the metabolism expressed by Lactobacillus delbrueckii subsp. delbrueckii CIRM-BIA865 during soy juice fermentation using transcriptomics. The whole genome was sequenced, assembled and annotated. CIRM-BIA865 was then used to ferment soy juice to produce a soy-based yogurt. Samples were analysed in kinetics during fermentation, at pH values of 6.5, 6, 5 and 4.6. RNA from CIRM-BIA865 were extracted and sequenced using paired-end Illumina. Reads were mapped using Bowtie2 on previously obtained genome of CIRM-BIA865. No mismatch were allowed. Reads mapped on CDS were counted using htseqcount.List of differentially expressed (DE) genes between two successive sampling times (determined by pH) were generated using DEseq2 with a modified t-test and a p-value adjusted by Bonferoni inferior to 0.05. Fold changes expressed how many times genes were induced along the fermentations.