scholarly journals Physiological Study of Lactobacillus delbrueckii subsp. bulgaricus Strains in a Novel Chemically Defined Medium

2000 ◽  
Vol 66 (12) ◽  
pp. 5306-5311 ◽  
Author(s):  
Christian Chervaux ◽  
S. Dusko Ehrlich ◽  
Emmanuelle Maguin
Keyword(s):  
Carbon Sources ◽  
Streptococcus Thermophilus ◽  
Defined Medium ◽  
Lactobacillus Delbrueckii ◽  
Protein Labeling ◽  
Chemically Defined Medium ◽  
Phosphotransferase System ◽  
Nutritional Conditions ◽  
Labeling Method

ABSTRACT We developed a chemically defined medium called milieu proche du lait (MPL), in which 22 Lactobacillus delbrueckii subsp.bulgaricus (L. bulgaricus) strains exhibited growth rates ranging from 0.55 to 1 h−1. MPL can also be used for cultivation of other lactobacilli and Streptococcus thermophilus. The growth characteristics of L. bulgaricus in MPL containing different carbon sources were determined, including an initial characterization of the phosphotransferase system transporters involved. For the 22 tested strains, growth on lactose was faster than on glucose, mannose, and fructose. Lactose concentrations below 0.4% were limiting for growth. We isolated 2-deoxyglucose-resistant mutants from strains CNRZ397 and ATCC 11842. CNRZ397-derived mutants were all deficient for glucose, fructose, and mannose utilization, indicating that these three sugars are probably transported via a unique mannose-specific-enzyme-II-like transporter. In contrast, mutants of ATCC 11842 exhibited diverse phenotypes, suggesting that multiple transporters may exist in that strain. We also developed a protein labeling method and verified that exopolysaccharide production and phage infection can occur in MPL. The MPL medium should thus be useful in conducting physiological studies ofL. bulgaricus and other lactic acid bacteria under well controlled nutritional conditions.

scholarly journals Aspartate Biosynthesis Is Essential for the Growth of Streptococcus thermophilus in Milk, and Aspartate Availability Modulates the Level of Urease Activity

2007 ◽  
Vol 73 (18) ◽  
pp. 5789-5796 ◽  
Author(s):  
Stefania Arioli ◽  
Christophe Monnet ◽  
Simone Guglielmetti ◽  
Carlo Parini ◽  
Ivano De Noni ◽  
...  
Keyword(s):  
Aspartic Acid ◽  
Phosphoenolpyruvate Carboxylase ◽  
Parent Strain ◽  
Urease Activity ◽  
Streptococcus Thermophilus ◽  
Defined Medium ◽  
Lactobacillus Delbrueckii ◽  
Chemically Defined Medium ◽  
Ammonium Ions ◽  
Carboxylase Activity

ABSTRACT We investigated the carbon dioxide metabolism of Streptococcus thermophilus, evaluating the phenotype of a phosphoenolpyruvate carboxylase-negative mutant obtained by replacement of a functional ppc gene with a deleted and inactive version, Δppc. The growth of the mutant was compared to that of the parent strain in a chemically defined medium and in milk, supplemented or not with l-aspartic acid, the final product of the metabolic pathway governed by phosphoenolpyruvate carboxylase. It was concluded that aspartate present in milk is not sufficient for the growth of S. thermophilus. As a consequence, phosphoenolpyruvate carboxylase activity was considered fundamental for the biosynthesis of l-aspartic acid in S. thermophilus metabolism. This enzymatic activity is therefore essential for growth of S. thermophilus in milk even if S. thermophilus was cultured in association with proteinase-positive Lactobacillus delbrueckii subsp. bulgaricus. It was furthermore observed that the supplementation of milk with aspartate significantly affected the level of urease activity. Further experiments, carried out with a p ureI -gusA recombinant strain, revealed that expression of the urease operon was sensitive to the aspartate concentration in milk and to the cell availability of glutamate, glutamine, and ammonium ions.

scholarly journals CHARACTERIZATION OF HAZELNUT MILK FERMENTED BY LACTOBACILLUS DELBRUECKII SUBSP. BULGARICUS AND STREPTOCOCCUS THERMOPHILUS

2018 ◽  
pp. 677-686 ◽  
Author(s):  
Ertan Ermiş ◽  
Rabia Güneş ◽  
İnci Zent ◽  
Muhammed Yusuf Çağlar ◽  
Mustafa Tahsin Yılmaz
Keyword(s):  
Streptococcus Thermophilus ◽  
Lactobacillus Delbrueckii ◽  
Lactobacillus Delbrueckii Subsp

The specificity of oligopeptide transport by Streptococcus thermophilus resembles that of Lactococcus lactis and not that of pathogenic streptococci

Microbiology ◽  
2005 ◽  
Vol 151 (6) ◽  
pp. 1987-1994 ◽  
Author(s):  
Odile Juille ◽  
Dominique Le Bars ◽  
Vincent Juillard
Keyword(s):  
Mass Spectrometry ◽  
Amino Acids ◽  
Time Course ◽  
Streptococcus Thermophilus ◽  
Defined Medium ◽  
Peptide Transport ◽  
Chemically Defined Medium ◽  
Crucial Step ◽  
Tryptic Digest ◽  
Transport Studies

Peptide transport is a crucial step in the growth of Streptococcus thermophilus in protein- or peptide-containing media. The objective of the present work was to determine the specificity of peptide utilization by this widely used lactic acid bacterium. To reach that goal, complementary approaches were employed. The capability of a proteinase-negative S. thermophilus strain to grow in a chemically defined medium containing a mixture of peptides isolated from milk as the source of amino acids was analysed. Peptides were separated into three size classes by ultrafiltration. The strain was able to use peptides up to 3·5 kDa during growth, as revealed by liquid chromatography and mass spectrometry analyses. The same strain was grown in chemically defined medium containing a tryptic digest of casein, and the respective time-course consumption of the peptides during growth was estimated. The ability to consume large peptides (up to 23 residues) was confirmed, as long as they are cationic and hydrophobic. These results were confirmed by peptide transport studies. Extension of the study to 11 other strains revealed that they all shared these preferences.

UTILIZATION OF CARBOHYDRATES BY ACTINOBACILLUS MALLEI

1966 ◽  
Vol 12 (4) ◽  
pp. 625-639 ◽  
Author(s):  
D. H. Evans
Keyword(s):  
Methylene Blue ◽  
Nitrogen Source ◽  
Ammonium Chloride ◽  
Carbon Sources ◽  
Defined Medium ◽  
Ammonium Citrate ◽  
Chemically Defined Medium ◽  
Negative Results ◽  
Proteose Peptone ◽  
Positive Results

Twenty-three substrains representing colonial variants of 11 strains of Actinabacillus mallei were examined for their ability to attack carbohydrates. Tests conducted in a basal liquid complex medium, containing yeast extract and proteose peptone No. 3 with bromcresol purple as indicator, showed that all strains tested produced acid from arabinose, glucose, fructose, galactose, mannose, and trehalose, while five substrains gave positive results with lactose, one with sucrose, and two with maltose. Eosin methylene blue agar of the same basal composition gave positive results for most of the strains grown on arabinose, glucose, fructose, galactose, mannose, and trehalose, and negative results for all strains grown on xylose, lactose, sucrose, and maltose. In a chemically defined medium containing ammonium chloride as nitrogen source and bromcresol purple as indicator, acid was produced by eight substrains of five of these strains from glucose, galactose, mannose, and trehalose, and by several strains from fructose and sucrose. The ability of these five selected strains to utilize carbohydrates as sole carbon sources for growth was tested in a chemically defined medium containing ammonium citrate as nitrogen source. All strains were able to grow on glucose, galactose, mannose, and trehalose, and most were able to grow on fructose. Arabinose, xylose, lactose, sucrose, and maltose did not support the growth of any of the strains tested.

Influence of ions on growth and production of exopolysaccharides by Lactobacillus delbrueckii subsp. bulgaricus NCFB 2772

2000 ◽  
Vol 67 (1) ◽  
pp. 131-135 ◽  
Author(s):  
GERT J. GROBBEN ◽  
INGEBORG C. BOELS ◽  
JAN SIKKEMA ◽  
MARK R. SMITH ◽  
JAN A. M. DE BONT
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Streptococcus Thermophilus ◽  
Defined Medium ◽  
Lactobacillus Delbrueckii ◽  
Sugar Composition ◽  
Carbohydrate Source ◽  
Medium Components ◽  
Number Of Factors ◽  
Initial Ph

Several lactic acid bacteria produce exopolysaccharides (EPS), either attached to the cell wall or excreted into the environment as slime material. EPS produced by Lactobacillus delbrueckii subsp. bulgaricus (Lb. bulgaricus) and Streptococcus thermophilus play an important role in improving the texture and stability of yogurt and preventing syneresis (Cerning, 1990; Nakajima et al. 1990). The amount and composition of the EPS produced by lactic acid bacteria are dependent on a number of factors, such as temperature, initial pH, carbon source and the availability of minerals, vitamins and other medium components.In previous work it was shown that the production and sugar composition of the EPS from Lb. bulgaricus NCFB2772 are affected by the carbohydrate source (Grobben et al. 1995, 1996). In a simplified defined medium, from which several vitamins and trace elements were omitted, EPS production by Lb. bulgaricus significantly increased, although growth of the strain was reduced (Grobben et al. 1998).

scholarly journals Genetic and Biochemical Characterization of the Phosphoenolpyruvate:Glucose/Mannose Phosphotransferase System of Streptococcus thermophilus

2003 ◽  
Vol 69 (9) ◽  
pp. 5423-5432 ◽  
Author(s):  
Armelle Cochu ◽  
Christian Vadeboncoeur ◽  
Sylvain Moineau ◽  
Michel Frenette
Keyword(s):  
Biochemical Characterization ◽  
Sugar Transport ◽  
Streptococcus Thermophilus ◽  
Phosphate Group ◽  
Phosphotransferase System ◽  
Whole Cells ◽  
Genes Encoding ◽  
Regulatory Functions

ABSTRACT In most streptococci, glucose is transported by the phosphoenolpyruvate (PEP):glucose/mannose phosphotransferase system (PTS) via HPr and IIABMan, two proteins involved in regulatory mechanisms. While most strains of Streptococcus thermophilus do not or poorly metabolize glucose, compelling evidence suggests that S. thermophilus possesses the genes that encode the glucose/mannose general and specific PTS proteins. The purposes of this study were to determine (i) whether these PTS genes are expressed, (ii) whether the PTS proteins encoded by these genes are able to transfer a phosphate group from PEP to glucose/mannose PTS substrates, and (iii) whether these proteins catalyze sugar transport. The pts operon is made up of the genes encoding HPr (ptsH) and enzyme I (EI) (ptsI), which are transcribed into a 0.6-kb ptsH mRNA and a 2.3-kb ptsHI mRNA. The specific glucose/mannose PTS proteins, IIABMan, IICMan, IIDMan, and the ManO protein, are encoded by manL, manM, manN, and manO, respectively, which make up the man operon. The man operon is transcribed into a single 3.5-kb mRNA. To assess the phosphotransfer competence of these PTS proteins, in vitro PEP-dependent phosphorylation experiments were conducted with purified HPr, EI, and IIABMan as well as membrane fragments containing IICMan and IIDMan. These PTS components efficiently transferred a phosphate group from PEP to glucose, mannose, 2-deoxyglucose, and (to a lesser extent) fructose, which are common streptococcal glucose/mannose PTS substrates. Whole cells were unable to catalyze the uptake of mannose and 2-deoxyglucose, demonstrating the inability of the S. thermophilus PTS proteins to operate as a proficient transport system. This inability to transport mannose and 2-deoxyglucose may be due to a defective IIC domain. We propose that in S. thermophilus, the general and specific glucose/mannose PTS proteins are not involved in glucose transport but might have regulatory functions associated with the phosphotransfer properties of HPr and IIABMan.

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