Project description:In this study, we investigated the impact of industrial antifoam agents on the physiology and transcriptome of the industrial ethanol Saccharomyces cerevisiae strain CAT-1. We showed that under industrial molasses fermentations similar to the ones used for ethanol production in Brazil, antifoam agents had detrimental effects on productivity, viability and lead to increased stress responses in yeast.
Project description:Pastick2009 - Genome-scale metabolic network
of Streptococcus thermophilus (iMP429)
This model is described in the article:
Genome-scale model of
Streptococcus thermophilus LMG18311 for metabolic comparison of
lactic acid bacteria.
Pastink MI, Teusink B, Hols P,
Visser S, de Vos WM, Hugenholtz J.
Appl. Environ. Microbiol. 2009 Jun;
75(11): 3627-3633
Abstract:
In this report, we describe the amino acid metabolism and
amino acid dependency of the dairy bacterium Streptococcus
thermophilus LMG18311 and compare them with those of two other
characterized lactic acid bacteria, Lactococcus lactis and
Lactobacillus plantarum. Through the construction of a
genome-scale metabolic model of S. thermophilus, the metabolic
differences between the three bacteria were visualized by
direct projection on a metabolic map. The comparative analysis
revealed the minimal amino acid auxotrophy (only histidine and
methionine or cysteine) of S. thermophilus LMG18311 and the
broad variety of volatiles produced from amino acids compared
to the other two bacteria. It also revealed the limited number
of pyruvate branches, forcing this strain to use the
homofermentative metabolism for growth optimization. In
addition, some industrially relevant features could be
identified in S. thermophilus, such as the unique pathway for
acetaldehyde (yogurt flavor) production and the absence of a
complete pentose phosphate pathway.
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MODEL1507180063.
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BioModels Database:
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quantitative kinetic models.
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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: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: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.
This model is hosted on BioModels Database
and identified by: MODEL1310300000
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication
for more information.
Project description:In this study we investigate the molecular physiology of the main S. cerevisiae commercial strain (PE-2) used on Brazilian bioethanol process under two distinct conditions: typical (TF) and flocculated (co-aggregated - FL) fermentation. Transcriptional machinery of PE-2 was assessed by high throughput sequencing-based methods (RNA-seq) during industrial fed-batch fermentations. Data from comparative analysis revealed distinct transcriptional profiles among conditions, characterized mainly by a deep gene repression on FL process.