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Series GSE45776 Query DataSets for GSE45776
Status Public on Aug 22, 2013
Title Transcriptome-based characterization of the interactions between Saccharomyces cerevisiae and Lactobacillus delbrueckii subsp. bulgaricus in lactose-grown chemostat co-cultures
Platform organism Saccharomyces cerevisiae
Sample organisms Lactobacillus delbrueckii subsp. bulgaricus; Saccharomyces cerevisiae
Experiment type Expression profiling by array
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 Lb. bulgaricus . S. cerevisiae and Lb. bulgaricus are both frequently encountered in kefir, a fermented dairy product (25). 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 (19,26-30). The design of the cultivation conditions was based on the observation that Lb. bulgaricus, but not S. cerevisiae, can use lactose as a carbon source for growth and that S. cerevisiae, but not Lb. 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. Lb. bulgaricus hydrolyses lactose, which cannot be metabolized by S. cerevisiae, to galactose and glucose. Subsequently, galactose, which cannot be metabolized by Lb. bulgaricus, is excreted and provides a carbon source for yeast. 2. In pure cultures, Lb. 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 Lb. bulgaricus. 5. Transcriptome analysis of Lb. 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. To our knowledge, this is the first transcriptome study of a cross-kingdom binary mixed culture that analyses responses of both microorganisms. This study demonstrates that chemostat-based transcriptome analysis is a powerful tool to investigated microbial interaction in mixed populations.
 
Overall design To investigate the impact of of co-cultivation with Lb. bulgaricus on S. cerevisiae, a DNA microarray-based transcriptome analysis of S. cerevisiae's response was performed on anaerobic, lactose-limited chemostat cultures grown in the presence and absence of L. bulgaricus.
 
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 Apr 04, 2013
Last update date Jul 01, 2016
Contact name Jean-Marc Daran
E-mail(s) j.g.daran@tudelft.nl
Phone +31 15 278 2412
Organization name Delft University of Technology
Department Department of Biotechnology
Lab Kluyver centre for genomics of industrial organisms
Street address Julianalaan 67
City Delft
ZIP/Postal code 2628BC
Country Netherlands
 
Platforms (1)
GPL90 [YG_S98] Affymetrix Yeast Genome S98 Array
Samples (6)
GSM1115025 Anaerobic lactose-limited chemostat pH6.0, 35°, mixed cullture S. cerevisiae AND Lb. bulgaricus (FM10L)
GSM1115026 Anaerobic lactose-limited chemostat pH6.0, 35°, mixed cullture S. cerevisiae AND Lb. bulgaricus (FM11R)
GSM1115027 Anaerobic lactose-limited chemostat pH6.0, 35°, mixed cullture S. cerevisiae AND Lb. bulgaricus (FM12)
Relations
BioProject PRJNA196305

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Supplementary file Size Download File type/resource
GSE45776_RAW.tar 7.7 Mb (http)(custom) TAR (of CEL)
Processed data included within Sample table

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