The impact of glycerol on the metabolism of Lactobacillus reuteri
Ontology highlight
ABSTRACT:
ORGANISM(S): Lactobacillus reuteri F275
SUBMITTER: Douwe Molenaar
PROVIDER: E-GEOD-11885 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Lactobacillus reuteri is a heterofermentative lactic acid bacterium best known for its ability to co-ferment glucose and glycerol. Its genome sequence has recently been deduced enabling the implementation of genome-wide analysis. In this study we developed a dedicated cDNA microarray platform and a genome-scale metabolic network model of L. reuteri and use them to revisit the co-fermentation of glucose and glycerol. The model was used to simulate experimental conditions and to visualize and integrate experimental data in particular the global transcriptional response of L. reuteri to the presence of glycerol. We show how the presence of glycerol affects cell physiology and triggers specific regulatory mechanisms allowing simultaneously a better yield and more efficient biomass formation. Furthermore we were able to predict and demonstrate for this well-studied condition the involvement of previously unsuspected metabolic pathways for instance related to amino acids and vitamins. These could be used as leads in future studies aiming at the increased production of industrially relevant compounds such as vitamin B12 or 1 3- propanediol. Keywords: cell type comparison Dye swap
2010-05-20 | E-GEOD-11860 | biostudies-arrayexpress
Project description:Recent functional genomics and genome-scale modeling approaches indicated that B12 production in Lactobacillus reuteri could be improved by medium optimization. Here we show that a series of systematic single amino acid omissions could significantly modulate the production of B12 from nearly undetectable levels (by isoleucine omission) to 20-fold higher than previously reported through omission of cysteine. We analyzed by cDNA microarray experiments the transcriptional response of L. reuteri to the medium lacking cysteine. These results supported the observed high B12 production and provided new avenues for future improvement of production of vitamin B12. Keywords: cell type comparison loop design
2010-05-17 | E-GEOD-13391 | biostudies-arrayexpress
Project description:Lactobacillus reuteri is a heterofermentative lactic acid bacterium best known for its ability to co-ferment glucose and glycerol. Its genome sequence has recently been deduced enabling the implementation of genome-wide analysis. In this study we developed a dedicated cDNA microarray platform and a genome-scale metabolic network model of L. reuteri and use them to revisit the co-fermentation of glucose and glycerol. The model was used to simulate experimental conditions and to visualize and integrate experimental data in particular the global transcriptional response of L. reuteri to the presence of glycerol. We show how the presence of glycerol affects cell physiology and triggers specific regulatory mechanisms allowing simultaneously a better yield and more efficient biomass formation. Furthermore we were able to predict and demonstrate for this well-studied condition the involvement of previously unsuspected metabolic pathways for instance related to amino acids and vitamins. These could be used as leads in future studies aiming at the increased production of industrially relevant compounds such as vitamin B12 or 1 3- propanediol. Keywords: cell type comparison Loop design
2008-09-15 | E-GEOD-11861 | biostudies-arrayexpress
Project description:Lactobacillus reuteri has been shown to encode a vitamin B12 biosynthesis pathway that is phylogenetically related to the one present in some representatives of gamma-proteobacteria such as Salmonella and Yersinia. Here we present evidence supporting that the similarities between these otherwise unrelated organisms extend to their regulatory mechanisms. Keywords: cell type comparison Loop design
2010-05-17 | E-GEOD-13289 | biostudies-arrayexpress
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.
2010-05-26 | E-GEOD-10194 | biostudies-arrayexpress
Project description:The SOS response is a conserved pathway that is activated under certain stress conditions and is regulated by the repressor LexA and the activator RecA. The food-borne pathogen Listeria monocytogenes contains RecA and LexA homologs, but their roles in Listeria have not been established. In this study, we identified the SOS regulon in L. monocytogenes by comparing the transcription profiles of the wild-type strain and the ÎrecA mutant strain after exposure to the DNA damaging agent mitomycinC (MMC). The SOS response is an inducible pathway involved in DNA repair, restart of stalled replication forks, and in induction of genetic variation in stressed and stationary phase cells. It is regulated by LexA and RecA. LexA is an autoregulatory repressor which binds to a consensus sequence in the promoter region of the SOS response genes, thereby repressing transcription. A consensus LexA binding motif for L. monocytogenes has not been identified thus far. Generally, the SOS response is induced under circumstances in which single stranded DNA accumulates in the cell. This results in activation of RecA, which in turn stimulates cleavage of LexA, and ultimately in the induction of the SOS response. Keywords: stress response, loop design, SOS response, mitomycin c, listeria monocytogenes, RecA, LexA Triple loop design of 3 independent experiments (series A, B, and C) using Wt strain and recA mutant (activator of the SOS response). Sampling was done before (t=0) and 1 hour after (t=60) exposure to mitomycin C (MMC) for both the wild-type strain and the recA mutant strain. One series therefore contains 4 samples and the complete experiments consists of 12 samples. Each of the 3 series was designed in a loop (wt, t=0 =>wt, t=60 => recA, t=60 => recA, t=0 => wt, t=0). These 3 loops were connected using series B as the central loop. Series B was connected to series A as follows: wt, t=0 (B) => recA, t=0 (A) and wt, t=60 (B) => recA, t=60 (A). Series B was connected to series C as follows: recA, t=0 (B) => wt, t=0 (C) and recA, t=60 (B) => wt, t=60 (C).
2010-05-19 | E-GEOD-12634 | biostudies-arrayexpress
Project description:Experimental evolution is a powerful approach to study how ecological forces shape microbial genotypes and phenotypes, but to date strains were predominantly adapted to conditions specific to laboratory environments. The lactic acid bacterium Lactococcus lactis naturally occurs on plants and in the dairy environment and it is generally believed, that dairy strains originate from the plant niche. Here we investigated the adaptive process from the plant to the dairy niche and show that during the experimental evolution of a L. lactis plant isolate in milk, several mutations are selected that affect amino acid metabolism and transport. Three independently evolved strains were characterized by whole genome re-sequencing, revealing 4 to 28 mutational changes in the individual strains. Two of the adapted strains showed clearly increased acidification rates and yields in milk, and contained three identical point mutations. Transcriptome profiling and extensive phenotyping of the wild-type plant isolate compared to the evolved mutants, and a "natural" dairy isolate confirmed that major physiological changes associated with improved performance in the dairy environment relate to nitrogen metabolism. The deletion of a putative transposable element led to a significant decrease of the mutation rate in two of the adapted strains. These results specify the adaptation of a L. lactis strain isolated from mung bean sprouts to growth in milk and they demonstrate that niche-specific adaptations found in environmental microbes can be reproduced by experimental evolution. Multiple loop design with 12 samples and 16 dual label arrays. Each sample is hybrdized at least on two different arrays and with both dyes.
2010-06-24 | E-GEOD-20373 | biostudies-arrayexpress
Project description:This data set contains samples from Lactobacillus plantarum WCFS1 wild type and its CcpA mutant derivative. Both strains were grown in duplicate (samples L and R) and at four different growth stages samples were taken (early, mid and late log phase, early stationary phase). Samples were compared to each other within one strain and between the two strains. This allows the comparison of the wild type strain to its CcpA derivative in time. Further it allows comparison within one strain during different growth stages. Biological duplicate was performed.
2010-09-10 | E-GEOD-24021 | biostudies-arrayexpress
Project description:Lactobacillus plantarum was grown anaerobically on 4 different sugars (Mannose Lactose Fructose and Sucrose) to OD600 = 1.0. Samples were compared with a similar grown culture on glucose. An independnet biological duplicate of tht experimnet was performed (samples 1 and 2). L. plantarum WCFS1 grown in glucose, mannose, fructose, and sucrose
2010-09-15 | E-GEOD-24098 | biostudies-arrayexpress
Project description:Analyses of the Wild type and the sigma 54 mutant strain NZ7306 with and without peroxide treatment: A Lactobacillus plantarum strain with a deletion in the alternative sigma factor 54 (?54) encoding gene rpoN, displayed a 100 fold higher sensitivity to peroxide as compared to its parental strain. This feature could be due to ?54-dependent regulation of genes involved in peroxide stress response. However, transcriptome analyses of the wild type and the mutant strain during peroxide exposure did not support such a role for ?54. Subsequent experiments revealed that the impaired expression of the mannose PTS operon in the rpoN mutant caused the observed increased peroxide sensitivity. Keywords: genetic modification Two conditions were tested in the transcriptome comparison, the condition “peroxide stress exposure” and the condition “deletion of the rpoN-gene”. This resulted in 4 samples: “Wild type normal”, “rpoN-mutant normal”, “Wild type with peroxide”, and “rpoN-mutant with peroxide”. Samples were hybridised against a sample with only one variation, resulting in a total of 4 hybridisations (“Wild type vs Mutant”, “Wild type vs Wild type peroxide”, “Mutant vs Mutant peroxide”, and “Wild type peroxide vs Mutant peroxide”). The experiment was performed in duplicate (duplicates are designated A and B) and in order to discriminate the variation between the duplicates additional hybridisation were performed: “Wild type A vs Wild type B” and “Mutant with peroxide A vs Mutant with peroxide B”. This resulted in a total of 10 hybridisations (2 x 4 and 2).
2008-05-08 | E-GEOD-11351 | biostudies-arrayexpress