The relevance of carbon dioxide metabolism in Streptococcus thermophilus

Abstract

Streptococcus thermophilus is a major component of dairy starter cultures used for the manufacture of yoghurt and cheese. In this study, the CO 2 metabolism of S. thermophilus DSM 20617 T , grown in either a N 2 atmosphere or an enriched CO 2 atmosphere, was analysed using both genetic and proteomic approaches. Growth experiments performed in a chemically defined medium revealed that CO 2 depletion resulted in bacterial arginine, aspartate and uracil auxotrophy. Moreover, CO 2 depletion governed a significant change in cell morphology, and a high reduction in biomass production. A comparative proteomic analysis revealed that cells of S. thermophilus showed a different degree of energy status depending on the CO 2 availability. In agreement with proteomic data, cells grown under N 2 showed a significantly higher milk acidification rate compared with those grown in an enriched CO 2 atmosphere. Experiments carried out on S. thermophilus wild-type and its derivative mutant, which was inactivated in the phosphoenolpyruvate carboxylase and carbamoyl-phosphate synthase activities responsible for fixing CO 2 to organic molecules, suggested that the anaplerotic reactions governed by these enzymes have a central role in bacterial metabolism. Our results reveal the capnophilic nature of this micro-organism, underlining the essential role of CO 2 in S. thermophilus physiology, and suggesting potential applications in dairy fermentation processes.

Isolation and characterization of a CO2-tolerant Lactobacillus strain from Crystal Geyser, Utah, U.S.A.

“…CO 2 enriched environments for cultured Lactobacilli are between 4 and 25% CO 2 (0.004-0.025 MPa) (Song et al, 2007;Bringel et al, 2008;Arioli et al, 2009). In contrast, CG-1 can grow at 1.0 MPa, or 40 times the CO 2 utilized by L. plantarum.…”

“…They are phylogenetically diverse, perform a variety of metabolic activities, and share very little evolutionary relationship to each other (Song et al, 2007;Bringel et al, 2008;Arioli et al, 2009). Capnophiles have been isolated from a variety of habitats including plants, mammalian cavities, wastewater, and animal rumens (Ballestra et al, 1996;Bringel et al, 2008;Ueda et al, 2008;Arioli et al, 2009).…”

“…While a large degree of attention has been given to these bacteria for food and disease studies, little has been given to their presence and environmental significance in the deep subsurface. Capnophiles may, for example, use CO 2 for metabolic processes such as in acetyl-CoA production, amino acid synthesis, or fermentation (e.g., Wynne and Foster, 1948;Maren, 1967;Smith and Ferry, 2000;Song et al, 2007;Arioli et al, 2009;Hertzberger et al, 2013).…”

Using Different Bioinformatics Software Tools for Determining the Carbon Dioxide (CO2) Dependence in Staphhylococcus aureus

“…The results of this study highlighted the importance of the CO 2 -dependent metabolism in the S. thermophilus physiology [12].…”

“…The results of this study highlighted the importance of the CO 2 -dependent metabolism in the S. thermophilus physiology [12]. Different study by Bringel and Hubert has considered the range of genetic lesions in the pathways of both pyrimidine and arginine biosynthesis [13].…”