Project description:Many food fermentations are carried out by mixed cultures of lactic acid bacteria. Interactions between strains are of key importance for the performance of these fermentations. Yoghurt fermentation by Streptoccus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (L.bulgaricus) is one of the best-described mixed culture fermentations. These species stimulate each other’s growth by the exchange of metabolites such as folic acid and carbon dioxide. Recently, post-genomic studies have been applied to reveal the global physiological response to mixed culture growth in S. thermophilus, but an in-depth molecular analysis of mixed culture growth of both strains remains to be established. Here we report the application of mixed culture transcriptome profiling and a systematic analysis of candidate interaction compounds on growth, which allowed the unraveling of the molecular responses associated with co-culture growth in batch of S. thermophilus CNRZ1066 and L. bulgaricus ATCC BAA-365 in milk. Comparisons of mono cultures versus mixed cultures, at four time-points in batch fermentation, and comparisons between the four time-points within each fermentation, all in duplicate
Project description:An aerobic Lactobacillus plantarum culture displayed growth stagnation during early growth. Transcriptome analysis revealed that regain of growth after stagnation correlated with activation of CO2-producing pathways suggesting that limiting CO2-concentration induced stagnation. Analogously providing increased CO2 gas partial pressure during aerobic fermentation prevented the temporal growth stagnation. Keywords: cell type comparison
Project description:Many food fermentations are carried out by mixed cultures of lactic acid bacteria. Interactions between strains are of key importance for the performance of these fermentations. Yoghurt fermentation by Streptoccus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus (L.bulgaricus) is one of the best-described mixed culture fermentations. These species stimulate each other’s growth by the exchange of metabolites such as folic acid and carbon dioxide. Recently, post-genomic studies have been applied to reveal the global physiological response to mixed culture growth in S. thermophilus, but an in-depth molecular analysis of mixed culture growth of both strains remains to be established. Here we report the application of mixed culture transcriptome profiling and a systematic analysis of candidate interaction compounds on growth, which allowed the unraveling of the molecular responses associated with co-culture growth in batch of S. thermophilus CNRZ1066 and L. bulgaricus ATCC BAA-365 in milk.
Project description:The aim of the study was to determine biological relevance of differentially expressed genes in Lactobacillus plantarum C2 during fermentation of plant substrates. Whole-transcriptome analysis based on customized microarray profiles has been used to determine altered transcription patterns in L. plantarum C2.
Project description:proteome-based techniques were used to compare changes of single culture fermentation and co-fermentation involving Lactobacillus plantarum Sx3 and Saccharomyces cerevisiae Sq7 in sourdough
Project description:The presence of anti-microbial phenolic compounds, such as the model compound ferulic acid, in biomass hydrolysates poses significant challenges to the widespread use of biomass in conjunction with whole cell biocatalysis or fermentation. Currently, these inhibitory compounds must be removed through additional downstream processing to create feedstock suitable for most industrially important microbial strains. This study explores the high ferulic acid tolerance in Lactobacillus brevis (L. brevis), a lactic acid bacteria often found in fermentation processes, by global transcriptional response analysis. The transcriptional profile of L. brevis under ferulic acid stress reveals that the presence of ferulic acid primarily triggers the expression of membrane proteins to counteract ferulic acid induced changes in membrane fluidity and ion leakage, in the midst of a generalized stress response. Several promising routes for understanding phenolic acid tolerance have been identified based upon these findings. These insights may be used to guide further engineering of model industrial organisms to better tolerate phenolic compounds in processed biomass.
Project description:An aerobic Lactobacillus plantarum culture displayed growth stagnation during early growth. Transcriptome analysis revealed that regain of growth after stagnation correlated with activation of CO2-producing pathways suggesting that limiting CO2-concentration induced stagnation. Analogously providing increased CO2 gas partial pressure during aerobic fermentation prevented the temporal growth stagnation. Keywords: cell type comparison Two aerobic fermenters (biological replicates Land R) were sampled at two time points, before (1) and after (2) growth stagnation.
