Nutritional Requirements of Lactobacillus delbrueckii subsp. lactis in a Chemically Defined Medium

2004 ◽  
Vol 49 (5) ◽  
pp. 341-345 ◽  
Author(s):  
Elvira M. H�bert ◽  
Raul R. Raya ◽  
Graciela Savoy de Giori
2000 ◽  
Vol 66 (12) ◽  
pp. 5306-5311 ◽  
Author(s):  
Christian Chervaux ◽  
S. Dusko Ehrlich ◽  
Emmanuelle Maguin

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.


1998 ◽  
Vol 64 (4) ◽  
pp. 1333-1337 ◽  
Author(s):  
G. J. Grobben ◽  
I. Chin-Joe ◽  
V. A. Kitzen ◽  
I. C. Boels ◽  
F. Boer ◽  
...  

ABSTRACT The aim of this work was to investigate the medium requirements for growth and production of exopolysaccharides by Lactobacillus delbrueckii subsp. bulgaricus NCFB 2772. The strain was grown in batch cultures on a chemically defined medium, and the technique of single omission of medium components was applied to determine the nutritional requirements. The omission of aspartic acid, glutamic acid, or glycine affected growth only slightly, and the omission of glutamine, asparagine, or threonine resulted in a stronger reduction of the growth. All the other amino acids were essential. Multiple omissions of amino acids caused an almost complete loss of growth. L. delbrueckii subsp. bulgaricusrequired only riboflavin, calcium pantothenate, and nicotinic acid as individual vitamins. Surprisingly, when only these vitamins were present in the medium and other vitamins were not, less growth was observed than in the complete medium but the amount of exopolysaccharide produced was significantly greater. These observations were studied in more detail with a simplified defined medium in which L. delbrueckii subsp.bulgaricus was able to grow and produce exopolysaccharides. Although the final optical density in the simplified medium was lower, the production of exopolysaccharides was about twofold higher than in the complete medium.


1972 ◽  
Vol 18 (1) ◽  
pp. 107-109
Author(s):  
G. E. Wessman ◽  
Geraldine Wessman

The nutritional requirements for culture of Pasteurella ureae in a chemically defined medium were determined. The medium in which the species grew best contained 16 amino acids: L-arginine, L-glutamic acid, L-alanine, and L-threonine were nutritionally essential; L-aspartic acid, L-leucine, and L-tryptophane were markedly stimulatory. The species also required uracil plus two purines, and two vitamins, nicotinamide and pantothenate.


1965 ◽  
Vol 11 (6) ◽  
pp. 1009-1019 ◽  
Author(s):  
Lillian V. Holdeman ◽  
Louis Ds. Smith

Clostridium botulinum type F was grown in a chemically defined medium containing 17 amino acids, 11 vitamins, glucose, and inorganic salts. The nutritional requirements were determined using single-omission test media. Arginine, tryptophan, tyrosine, valine, biotin, thiamin, and possibly methionine were essential nutrients. Growth was stimulated by glycine, isoleucine, phenylalanine, and para-aminobenzoic acid. Toxin was present in supernatant fluids from all synthetic medium cultures in which there was marked growth. In general, toxicity of synthetic medium cultures was about 1/10 that of complex medium cultures.Toxin and precursor appear to be formed intracellularly, for both were released by rupturing young cells with sonic vibration. Protoxin could be activated by treatment with trypsin.


2000 ◽  
Vol 66 (8) ◽  
pp. 3427-3431 ◽  
Author(s):  
Sandrine Petry ◽  
Sylviane Furlan ◽  
Marie-Jeanne Crepeau ◽  
Jutta Cerning ◽  
Michel Desmazeaud

ABSTRACT We developed a chemically defined medium (CDM) containing lactose or glucose as the carbon source that supports growth and exopolysaccharide (EPS) production of two strains ofLactobacillus delbrueckii subsp. bulgaricus. The factors found to affect EPS production in this medium were oxygen, pH, temperature, and medium constituents, such as orotic acid and the carbon source. EPS production was greatest during the stationary phase. Composition analysis of EPS isolated at different growth phases and produced under different fermentation conditions (varying carbon source or pH) revealed that the component sugars were the same. The EPS from strain L. delbrueckii subsp.bulgaricus CNRZ 1187 contained galactose and glucose, and that of strain L. delbrueckii subsp. bulgaricusCNRZ 416 contained galactose, glucose, and rhamnose. However, the relative proportions of the individual monosaccharides differed, suggesting that repeating unit structures can vary according to specific medium alterations. Under pH-controlled fermentation conditions, L. delbrueckii subsp. bulgaricusstrains produced as much EPS in the CDM as in milk. Furthermore, the relative proportions of individual monosaccharides of EPS produced in pH-controlled CDM or in milk were very similar. The CDM we developed may be a useful model and an alternative to milk in studies of EPS production.


2000 ◽  
Vol 66 (12) ◽  
pp. 5316-5321 ◽  
Author(s):  
Elvira M. Hebert ◽  
Raul R. Raya ◽  
Graciela S. De Giori

ABSTRACT The nutritional requirements of Lactobacillus helveticus CRL 1062 were determined with a simplified chemically defined medium (SCDM) and compared with those of L. helveticus CRL 974 (ATCC 15009). Both strains were found to be prototrophic for alanine, glycine, asparagine, glutamine, and cysteine. In addition, CRL 1062 also showed prototrophy for lysine and serine. The microorganisms also required riboflavin, calcium pantothenate, pyridoxal, nicotinic acid, and uracil for growth in liquid SCDM. The growth rate and the synthesis of their cell membrane-bound serine proteinases, but not of their intracellular leucyl-aminopeptidases, were influenced by the peptide content of the medium. The highest proteinase levels were found during cell growth in basal SCDM, while the synthesis of this enzyme was inhibited in SCDM supplemented with Casitone, Casamino Acids, or β-casein. Low-molecular-mass peptides (<3,000 Da), extracted from Casitone, and the dipeptide leucylproline (final concentration, 5 mM) play important roles in the medium-dependent regulation of proteinase activity. The addition of the dipeptide leucylproline (5 mM) to SCDM reduced proteinase activity by 25%.


2007 ◽  
Vol 73 (18) ◽  
pp. 5789-5796 ◽  
Author(s):  
Stefania Arioli ◽  
Christophe Monnet ◽  
Simone Guglielmetti ◽  
Carlo Parini ◽  
Ivano De Noni ◽  
...  

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.


1974 ◽  
Vol 20 (2) ◽  
pp. 263-265 ◽  
Author(s):  
Edward E. Ishiguro

A chemically defined medium for host-independent (H-I) derivatives of Bdellovibrio bacteriovorus strain 109 Davis has been developed. Carbon-source utilization studies indicated that H-I cells can assimilate a wider variety of compounds than host-dependent bdellovibrios. The defined medium did not support growth of freshly isolated H-I strains which required unidentified growth factors present in Escherichia coli cell-free extracts and in yeast extract.


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