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| Status |
Public on Apr 01, 2013 |
| Title |
Transcriptome-based characterization of the interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaricus in lactose-grown chemostat co-cultures |
| Platform organism |
Lactobacillus delbrueckii subsp. bulgaricus ATCC BAA-365 |
| Sample organisms |
Lactobacillus delbrueckii subsp. bulgaricus; Saccharomyces cerevisiae |
| Experiment type |
Expression profiling by array
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| Summary |
The present study aims to explore chemostat-based transcriptome analysis of mixed cultures by investigating interactions between the yeast S. cerevisiae and the lactic acid bacterium L. bulgaricus . S. cerevisiae and L. bulgaricus are both frequently encountered in kefir, a fermented dairy product. In the context of this study, this binary culture serves as a model for the many traditional food and beverage fermentation processes in which yeasts and lactic acid bacteria occur together. The design of the cultivation conditions was based on the observation that L. bulgaricus, but not S. cerevisiae, can use lactose as a carbon source for growth and that S. cerevisiae, but not L. bulgaricus, can grow on galactose that is released upon hydrolysis of lactose by the bacterial β-galactosidase.
Mixed populations of yeasts and lactic acid bacteria occur in many dairy, food and beverage fermentations, but knowledge about their interactions is incomplete. In the present study, interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaricus, two microorganisms that co-occur in kefir fermentations, were studied during anaerobic growth on lactose. By combining physiological and transcriptome analysis of the two strains in the co-cultures, five mechanisms of interaction were identified. 1. L. bulgaricus hydrolyses lactose, which cannot be metabolized by S. cerevisiae, to galactose and glucose. Subsequently, galactose, which cannot be metabolized by L. bulgaricus, is excreted and provides a carbon source for yeast. 2. In pure cultures, L. bulgaricus only grows at increased CO2 concentrations. In anaerobic mixed cultures, the yeast provides this CO2 via alcoholic fermentation. 3. Analysis of amino acid consumption from the defined medium indicated that S. cerevisiae supplied alanine to the bacteria. 4. A mild but significant low-iron response in the yeast transcriptome, identified by DNA microarray analysis, was consistent with the chelation of iron by the lactate produced by L. bulgaricus. 5. Transcriptome analysis of L. bulgaricus in mixed cultures showed an overrepresentation of transcripts involved in lipids metabolism suggesting either a competition of the two microorganisms for fatty acids, or a response to the ethanol produced by S. cerevisiae.
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| Overall design |
To investigate the impact of of co-cultivation with S. cerevisiae on L. bulgaricus, a DNA microarray-based transcriptome analysis of L. bulgaricus response was performed on anaerobic, lactose-limited chemostat cultures grown in the presence and absence of S. cerevisae.
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| Contributor(s) |
Mendes F, Sieuwerts S, de Hulster E, Almering MJ, Luttik MA, Pronk JT, Smid EJ, Bron PA, Daran-Lapujade P |
| Citation(s) |
23872557 |
| Submission date |
Mar 29, 2013 |
| Last update date |
Aug 22, 2013 |
| Contact name |
Sander Sieuwerts |
| Organization name |
Arla Foods
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| Department |
Arla Scientific Innovation Centre
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| Lab |
Microbial Cultures and Enzymes
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| Street address |
rørdrumvej 2
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| City |
Brabrand |
| ZIP/Postal code |
8220 |
| Country |
Denmark |
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| Platforms (1) |
| GPL16855 |
Agilent TIFN Lactobacillus bulgaricus arrays, TB1_8, Version 1 |
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| Samples (4)
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| GSM1111960 |
Mono culture type 1_mixed culture type 1 [chemostat cultures] |
| GSM1111961 |
Mixed culture type 1_mono culture type 1 [chemostat cultures] |
| GSM1111962 |
Mono culture type 2_mixed culture type 2 [batch cultures] |
| GSM1111963 |
Mixed culture type 2_mono culture type 2 [batch cultures] |
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| Relations |
| BioProject |
PRJNA195611 |
| Supplementary file |
Size |
Download |
File type/resource |
| GSE45623_RAW.tar |
4.3 Mb |
(http)(custom) |
TAR (of TXT) |
| Processed data included within Sample table |
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