Ontology highlight
ABSTRACT:
PROVIDER: PRJNA1200125 | ENA |
REPOSITORIES: ENA
Dataset's files
| Action | DRS | |||
|---|---|---|---|---|
| SRR31768939_1.fastq.gz | Fastqsanger.gz | |||
| SRR31768939_2.fastq.gz | Fastqsanger.gz | |||
| SRR31768940_1.fastq.gz | Fastqsanger.gz | |||
| SRR31768940_2.fastq.gz | Fastqsanger.gz | |||
| SRR31768941_1.fastq.gz | Fastqsanger.gz |
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Similar Datasets
Project description:Lactococcus lactis diversity in an undefined mixed dairy starter culture
| PRJNA615395 | ENA
Project description:Lactococcus lactis diversity in an undefined mixed dairy starter culture
| PRJNA615620 | ENA
Project description:Purpose: Lactococcus lactis is the primary constituent of many industrial starter cultures used in food fermentations. However, this bacterium is exposed to several stressful conditions during the industrial process. L. lactis TOMSC161 has been shown to resist better to freeze-drying and storage when cells are harvested at the late stationary compared to the early stationary phase. Methods: In this work, the physiological changes that occur during growth (early and late stationary phases) were studied using transcriptomic, proteomic and cytometric approaches in order to elucidate the cell mechanisms involved in the stress tolerance of L. lactis TOMSC161 to freeze-drying and storage processes. Results: The majority of altered abundances for genes determined by transcriptomic analysis indicated a slowdown at the late stationary phase in general metabolism and in the incomplete reduction of O2 leading to reactive oxygen species (ROS), in comparison to the early stationary phase. Furthermore, the expression of genes involved in general and oxidative stress responses was over-expressed at the late stationary phase when compared to the early stationary phase, thus explaining the better resistance to freeze-drying and the storage of cells harvested after six hours of stationary phase. Superoxide anion detection was performed by flow cytometry and related to the ROS production of starters. Superoxide anion concentration was lower for cells harvested at the late stationary phase when compared to cells harvested at the early stationary phase. Conclusions: L. lactis TOMSC161 was thus able to develop an oxidative stress “pre-adaptation” during the stationary phase making it possible to better resist freeze-drying and storage stresses and especially oxidative stress.
2018-10-30 | GSE74554 | GEO
Project description:Gene expression in Lactococcus lactis MG1363 was compared to that of L. lactis MG1363 ∆guaA in rich GM17 medium.
2016-01-12 | GSE76764 | GEO
Project description:The viability of starter cultures is essential for an adequate contribution to the fermentation process and end-product. Therefore, robustness during processing and storage is an important characteristic of starter culture strains. For instance, during spray drying cells are exposed to heat and oxidative stress, generally resulting in loss of viability. In this study, we exposed the industrially relevant but stress-sensitive Lactococcus lactis strain SK11 to two cycles of heat stress, with intermediate recovery and cultivation at moderate temperatures. After these two cycles of heat exposure, the abundance of robust derivatives was increased as compared with the original culture, which enabled isolation of heat-resistant subpopulations displaying up to 1000-fold enhanced heat stress survival. Moreover, this heat-resistant subpopulation demonstrated an increased survival during spray drying. Derivatives from two independent lineages displayed different transcriptome changes as compared with the wild type strain, indicating that the increased robustness within these lineages was established by different adaptive strategies. Nevertheless, an overlap in differential gene expression in all five derivatives tested in both lineages included three genes in an operon involved in zinc transport. The link between zinc homeostasis and heat stress survival in L. lactis was experimentally established by culturing of the wild type strain SK11 in medium with various levels of zinc ions, which resulted in alterations in heat stress survival phenotypes. This study demonstrates that robust derivatives of a relatively sensitive L. lactis strain can be isolated by repeated exposure to heat stress. Moreover, this work demonstrates that transcriptome analysis of these robust derivatives can provide clues for improvement of the robustness of the original strain. This could boost the industrial application of strains with specific desirable traits but inadequate robustness characteristics.
2018-09-08 | GSE119647 | GEO
Project description:Effect of the presence of Lactococcus lactis on Staphylococcus aureus transcriptome in cheese matrix. S. aureus was co-cultured with L. lactis LD61 in cheese matrix during 7 days. RNA samples were extracted at different time points (6 h, 8 h, 10 h, 24 h and 7 days) in order to monitor the dynamic response of S. aureus MW2 in cheese matrix in presence of L. lactis
2011-07-01 | E-MEXP-2842 | biostudies-arrayexpress
Project description:This study describes a transcriptome-phenotype matching approach in which the starter L. lactis MG1363 was fermented under a variety of conditions that differed in the levels of oxygen and/or salt, as well as the fermentation pH and temperature. Samples derived from these fermentations in the exponential phase of bacterial growth were analyzed by full-genome transcriptomics and the assessment of heat and oxidative stress phenotypes. Variations in the fermentation conditions resulted in up to 1000-fold differences in survival during heat and oxidative stress. More specifically, aeration during fermentation induced protection against heat stress, whereas a relatively high fermentation temperature resulted in enhanced robustness towards oxidative stress. Concomitantly, oxygen levels and fermentation temperature induced differential expression of markedly more genes when compared with the other fermentation parameters. Correlation analysis of robustness phenotypes and gene expression levels revealed transcriptome signatures for oxidative and/or heat stress survival, including the metC-cysK operon involved in methionine and cysteine metabolism. To validate this transcriptome-phenotype association we grew L. lactis MG1363 in the absence of cysteine which led to enhanced robustness towards oxidative stress. Conclusions Overall, we demonstrated the importance of careful selection of fermentation parameters prior to industrial processing of starter cultures. Furthermore, established stress genes as well as novel genes were associated with robustness towards heat and/or oxidative stress. Assessment of the expression levels of this group of genes could function as an indicator for enhanced selection of fermentation parameters resulting in improved robustness during spray drying. The increased robustness after growth without cysteine appeared to confirm the role of expression of the metC-cysK operon as an indicator of robustness and suggests that sulfur amino acid metabolism plays a pivotal role in oxidative stress survival. two connected loops, both containing samples derived on a single day (sample 1-6, sample 7-13)
2014-08-01 | E-GEOD-58284 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE23987: Transcriptomic profiles of six strains of Lactococcus lactis in ultrafiltration-cheese model GSE23990: Comparative genome hybridization profiles of six strains of Lactococcus lactis Refer to individual Series
2012-09-07 | E-GEOD-24015 | biostudies-arrayexpress
Project description:Salinity seriously reduces the yield and quality of crops. Silicon (Si) has been widely reported to have beneficial effects on plant growth and development under salt stress. However, the mechanism is still poorly understood. In an attempt to identify genes or gene networks that may be orchestrated to improve salt tolerance of cucumber plants, we profiled the RNA-seq transcriptomes of both control and salt-stressed cucumber leaves in the presence or absence of added Si. The comparative transcriptome analysis revealed that Si plays an important role in shaping the transcriptome of cucumber: the expression levels of >1,000 genes (differtially expressed genes, DEGs) were changed in response to Si treatment as compared with the control, and these genes were mainly involved in ion transport, hormone and signal transduction, biosynthesis and metabolic processes, stress and defense responses, and antioxidant activity. Under salt stress, many genes functionally associated with metabolic processes and responses to environmental stimuli were strongly up- or down-regulated in their expressions. Si treatment showed a tendency that induced the transcriptomic profile of salt-stressed cucumber back to that of the control with large majority of Na down-regulated DEGs and about half of Na up-regulated DEGs being adjusted back to CT levels. This study provides a novel insight into the mechanism for Si-mediated alleviation of salt stress in plants at the transcriptome level, and it suggests that Si may act as an elicitor to precondition cucumber plants and induce salt tolerance.
2018-06-27 | GSE116265 | GEO
Project description:Flahaut2013 - Genome-scale metabolic model of L.lactis (MG1363)
Genome-scale metabolic model for Lactococcus lactis
MG1363 and its application to the analysis of flavor formation.
This model is described in the article:
Genome-scale metabolic model for Lactococcus lactis MG1363 and its application to the analysis of flavor formation.
Flahaut NA, Wiersma A, van de Bunt B, Martens DE, Schaap PJ, Sijtsma L, Dos Santos VA, de Vos WM
Applied Microbiology and Biotechnology. 2013; 97(19):8729-8739
Abstract:
Lactococcus lactis subsp. cremoris MG1363 is a paradigm strain for lactococci used in industrial dairy fermentations. However, despite of its importance for process development, no genome-scale metabolic model has been reported thus far. Moreover, current models for other lactococci only focus on growth and sugar degradation. A metabolic model that includes nitrogen metabolism and flavor-forming pathways is instrumental for the understanding and designing new industrial applications of these lactic acid bacteria. A genome-scale, constraint-based model of the metabolism and transport in L. lactis MG1363, accounting for 518 genes, 754 reactions, and 650 metabolites, was developed and experimentally validated. Fifty-nine reactions are directly or indirectly involved in flavor formation. Flux Balance Analysis and Flux Variability Analysis were used to investigate flux distributions within the whole metabolic network. Anaerobic carbon-limited continuous cultures were used for estimating the energetic parameters. A thorough model-driven analysis showing a highly flexible nitrogen metabolism, e.g., branched-chain amino acid catabolism which coupled with the redox balance, is pivotal for the prediction of the formation of different flavor compounds. Furthermore, the model predicted the formation of volatile sulfur compounds as a result of the fermentation. These products were subsequently identified in the experimental fermentations carried out. Thus, the genome-scale metabolic model couples the carbon and nitrogen metabolism in L. lactis MG1363 with complete known catabolic pathways leading to flavor formation. The model provided valuable insights into the metabolic networks underlying flavor formation and has the potential to contribute to new developments in dairy industries and cheese-flavor research.
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2005-01-01 | MODEL1310300000 | BioModels