Project description:Kefir is a milk fermented by microorganisms with probiotic potential. Its consumption is associated with several beneficial effects, from antibacterial, healing, antioxidant, anti-inflammatory, anti-allergic, plasma glucose and cholesterol control to antitumor and antihypertensive activities. Despite its great potential, little is known about the bioactive molecules responsible for these actions. Therefore, the present project aims to perform the proteomic study of Kefir and its grain used for the milk fermentation aiming to identify the bioactive peptides, in particular those peptides with action in the cardiovascular system.
Project description:This study examines the proteolytic activity of the kefir grains (a combination of bacteria and yeast) on bovine milk proteins. SDS-PAGE analysis reveals substantial digestion of milk proteins by the kefir grains in comparison with control samples. Mass spectrometric analysis reveals that the kefir microorganisms released 609 new peptide fragments and significantly altered the abundance of around 1,500 peptides compared to the controls. These kefir-digested peptides derived from 55 milk proteins. We show that kefir contains 25 previously identified functional peptides with actions including antihypertensive, antimicrobial, opioid and anti-oxidative .
Project description:Multi-omics has the promise to provide a detailed molecular picture for biological systems. Although obtaining multi-omics data is relatively easy, methods that analyze such data have been lagging. In this paper, we present an algorithm that uses probabilistic graph representations and external knowledge to perform optimum structure learning and deduce a multifarious interaction network for multi-omics data from a bacterial community. Kefir grain, a microbial community that ferments milk and creates kefir, represents a self-renewing, stable, natural microbial community. Kefir has been shown to associate with a wide range of health benefits. We obtained a controlled bacterial community using the two most abundant and well-studied species in kefir grains: Lentilactobacillus kefiri and Lactobacillus kefiranofaciens. We applied growth temperatures of 30°C and 37°C, and ob-tained transcriptomic, metabolomic, and proteomic data for the same 20 samples (10 samples per temperature). We obtained a multi-omics interaction network, which generated insights that would not have been possible with single-omics analysis. We identified interactions among transcripts, proteins, and metabolites suggesting active toxin/antitoxin systems. We also observed multifarious interactions that involved the shikimate pathway. These observations helped explain bacterial adaptation to different stress conditions, co-aggregation, and increased activation of L. kefiranofa-ciens at 37°C.
Project description:<p>Microbial communities often undergo intricate compositional changes yet also maintain stable coexistence of diverse species. The mechanisms underlying long-term coexistence remain unclear, as system-wide studies have been largely limited to engineered communities, ex situ adapted cultures, or synthetic assemblies. Here we show how kefir, a natural milk-fermenting community of prokaryotes and yeasts, realises stable coexistence through spatiotemporal orchestration of species and metabolite dynamics. During milk fermentation, kefir grains (a polysaccharide matrix synthesized by kefir microbes) grow in mass but remain unchanged in composition. In contrast, the milk is colonized in a sequential manner in which early members open metabolic niches for followers. Through metabolomics and large-scale mapping of inter-species interactions, we show how microbes poorly suited for milk survive in, and even dominate the community, through metabolic cooperation and uneven partitioning between grain and milk. Overall, our findings reveal how inter-species interactions partitioned in space and time lead to stable coexistence.</p><p><br></p><p><strong>Linked metabolomics studies:</strong></p><p><a href='https://www.ebi.ac.uk/metabolights/MTBLS1829' rel='noopener noreferrer' target='_blank'>MTBLS1829</a> Kefir fermentation curve (FIA-MS)</p><p><a href='https://www.ebi.ac.uk/metabolights/MTBLS1830' rel='noopener noreferrer' target='_blank'>MTBLS1830</a> Interaction between the kefir isolates Lactococcus lactis and Acetobacter fabarum (GC-MS)</p><p><br></p><p><strong>Linked cross omic data:</strong></p><p>Genomes of isolated kefir species are available in the <a href='https://www.ncbi.nlm.nih.gov/' rel='noopener noreferrer' target='_blank'>NCBI database</a> under the accession: PRJNA375758 (bioproject ID: 375758).</p><p>Metatranscriptomic sequencing reads can be accessed from <a href='www.ebi.ac.uk/ena' rel='noopener noreferrer' target='_blank'>ENA</a> under the project id PRJEB37001.</p><p>Genome-scale metabolic models for kefir bacteria can be found at github.com/cdanielmachado/kefir_models.</p>
Project description:<p>Microbial communities often undergo intricate compositional changes yet also maintain stable coexistence of diverse species. The mechanisms underlying long-term coexistence remain unclear, as system-wide studies have been largely limited to engineered communities, ex situ adapted cultures, or synthetic assemblies. Here we show how kefir, a natural milk-fermenting community of prokaryotes and yeasts, realizes stable coexistence through spatiotemporal orchestration of species and metabolite dynamics. During milk fermentation, kefir grains (a polysaccharide matrix synthesized by kefir microbes) grow in mass but remain unchanged in composition. In contrast, the milk is colonized in a sequential manner in which early members open metabolic niches for followers. Through metabolomics and large-scale mapping of inter-species interactions, we show how microbes poorly suited for milk survive in — and even dominate — the community, through metabolic cooperation and uneven partitioning between grain and milk. Overall, our findings reveal how inter-species interactions partitioned in space and time lead to stable coexistence.</p><p><br></p><p><strong>Linked metabolomics studies:</strong></p><p><a href='https://www.ebi.ac.uk/metabolights/MTBLS1823' rel='noopener noreferrer' target='_blank'>MTBLS1823</a> Spent-medium assay, measured untargeted (FIA-qTOF) and targeted (HILIC, LC-MS)</p><p><a href='https://www.ebi.ac.uk/metabolights/MTBLS1829' rel='noopener noreferrer' target='_blank'>MTBLS1829</a> Kefir fermentation curve (FIA-MS)</p><p><br></p><p><strong>Linked cross omic data:</strong></p><p>Genomes of isolated kefir species are available in the <a href='https://www.ncbi.nlm.nih.gov/' rel='noopener noreferrer' target='_blank'>NCBI database</a> under the accession: PRJNA375758 (bioproject ID: 375758).</p><p>Metatranscriptomic sequencing reads can be accessed from <a href='https://www.ebi.ac.uk/metabolights/editor/www.ebi.ac.uk/ena' rel='noopener noreferrer' target='_blank'>ENA</a> under the project id PRJEB37001.</p><p>Genome-scale metabolic models for kefir bacteria can be found at github.com/cdanielmachado/kefir_models.</p>
Project description:<p>Microbial communities often undergo intricate compositional changes yet also maintain stable coexistence of diverse species. The mechanisms underlying long-term coexistence remain unclear, as system-wide studies have been largely limited to engineered communities, ex situ adapted cultures, or synthetic assemblies. Here we show how kefir, a natural milk-fermenting community of prokaryotes and yeasts, realises stable coexistence through spatiotemporal orchestration of species and metabolite dynamics. During milk fermentation, kefir grains (a polysaccharide matrix synthesized by kefir microbes) grow in mass but remain unchanged in composition. In contrast, the milk is colonized in a sequential manner in which early members open metabolic niches for followers. Through metabolomics and large-scale mapping of inter-species interactions, we show how microbes poorly suited for milk survive in, and even dominate the community, through metabolic cooperation and uneven partitioning between grain and milk. Overall, our findings reveal how inter-species interactions partitioned in space and time lead to stable coexistence.</p><p><br></p><p><strong>Linked metabolomics studies:</strong></p><p><a href='https://www.ebi.ac.uk/metabolights/MTBLS1823' rel='noopener noreferrer' target='_blank'>MTBLS1823</a> Spent-medium assay, measured untargeted (FIA-qTOF) and targeted (HILIC, LC-MS)</p><p><a href='https://www.ebi.ac.uk/metabolights/MTBLS1830' rel='noopener noreferrer' target='_blank'>MTBLS1830</a> Interaction between the kefir isolates Lactococcus lactis and Acetobacter fabarum (GC-MS)</p><p><br></p><p><strong>Linked cross omic data sets:</strong></p><p>Genomes of isolated kefir species are available in the NCBI database under the accession: PRJNA375758 (bioproject ID: 375758).</p><p>Metatranscriptomic sequencing data associated with this study are available in the European Nucleotide Archive (ENA): accession number <a href='https://www.ebi.ac.uk/ena/browser/view/PRJEB37001' rel='noopener noreferrer' target='_blank'>PRJEB37001</a>.</p><p>Genome-scale metabolic models for kefir bacteria can be found at github.com/cdanielmachado/kefir_models.</p>
2020-11-04 | MTBLS1829 | MetaboLights
Project description:Tibetan kefir grain bacterial community
| PRJNA750869 | ENA
Project description:Metagenomic of Tibetan kefir grain
Project description:In this study, we applied a proteomics strategy to identify peptides present in sheep milk kefir fermented at different times. We aimed to understand changes in the digestion pattern of milk proteins as well as to identify potential bioactive peptides.