Growth of Legionella pneumophila in defined media: requirement for magnesium and potassium

1982 ◽  
Vol 28 (9) ◽  
pp. 1055-1058 ◽  
Author(s):  
Martha J. Tesh ◽  
Richard D. Miller

The inorganic ions magnesium and potassium were required for optimal growth of Legionella pneumophila in a chemically defined medium composed of amino acids and inorganic salts. Optimum growth was obtained at concentrations of approximately 20 μg/mL (80 μM) MgSO4∙7H2O and 150 μg/mL (2 mM) KCl. Comparable results were obtained with all six serogroups of L. pneumophila as well as with both laboratory-adapted and animal-passed strains.

2008 ◽  
Vol 60 (4) ◽  
pp. 509-517 ◽  
Author(s):  
Jelena Lozo ◽  
Jelena Begovic ◽  
B. Jovcic ◽  
Natasa Golic ◽  
L. Topisirovic

The purpose of this study was to determine the ability of natural isolates of lactobacilli from different ecological niches to grow in a chemically defined medium in the presence or absence of sulphur-containing amino acids, methionine and/or cysteine. The obtained results indicate that cysteine is essential for growth of L. paracasei subsp. paracasei BGHN14 and BGSJ2-8, while methionine is essential for isolates BGHN40, BGCG31, and BGHV54T of the species L. plantarum. Methionine is also essential for growth of L. rhamnosus BGHV58T. Other analyzed strains, such as L. plantarum BGSJ3-18, BGZB19, BGHV52Ta, and BGHV43T, require the presence of both amino acids for their growth.


1963 ◽  
Vol 9 (4) ◽  
pp. 619-624 ◽  
Author(s):  
Ian D. Dundas ◽  
V. R. Srinivasan ◽  
H. Orin Halvorson

A chemically defined medium has been composed for Halobacterium salinarium strain 1. The medium consists of inorganic salts, 10 amino acids (lysine, arginine, proline, valine, methionine, isoleucine, leucine, tyrosine, phenylalanine, and glutamine) and cytidylic acid. The amino acids valine, methionine, isoleucine, and leucine are found to be essential for growth in this medium. Growth rates in the synthetic medium are not as high as those obtained in complex media. The medium allows growth of several halophilic organisms.


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.


1972 ◽  
Vol 18 (7) ◽  
pp. 1087-1090 ◽  
Author(s):  
C. P. Kenny ◽  
B. B. Diena ◽  
R. Wallace ◽  
L. Greenberg

Neisseria Chemically Defined Medium (NCDM) has been used routinely in our laboratory for a variety of purposes. The present report describes the development of NCDM agar, wherein the NCDM base is sterilized by filtration and defined supplements and agar are added. The medium is transparent and both meningococci and gonococci grow within 72 h. When grown on NCDM agar, Types 2 and 3 gonococcal colonies tend to revert to Type 1. The serological grouping of meningococci with specific antisera is not affected by growth on this medium.Parallel investigations on the growth of these species in liquid NCDM demonstrated that the yield of Neisseria gonorrhoeae is enhanced when the medium is sterilized by filtration.


1950 ◽  
Vol 28c (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. H. Wallace ◽  
A. G. Lochhead

A study was made of the more specific amino acid requirements of bacteria from the rhizospheres of clover, flax, and wheat plants for which a chemically defined medium containing 23 amino acids provided essentials for maximum growth. Of seven groups of amino acids, the sulphur-containing group (cysteine, methionine, and taurine) was found to be of special significance, the omission of this group resulting in a pronounced decrease in the percentage of organisms able to develop. Further study of organisms dependent upon this group of amino acids for growth showed methionine to be by far the most essential compound. While evident for bacteria from the rhizosphere of all three crops, the effect was more pronounced in the case of clover than with flax or wheat.


1966 ◽  
Vol 12 (4) ◽  
pp. 641-652 ◽  
Author(s):  
D. H. Evans

Growth of Actinobacillus mallei was inhibited by kanamycin; the minimal inhibitory concentration in a complex medium was 1.25 μg/ml and in a chemically defined medium 5 μg/ml. Higher concentrations of kanamycin had a pronounced bactericidal effect. When a suspension of cells containing 5 × 107 viable cells/ml was incubated in the presence of 20 μg/ml of kanamycin in a chemically defined medium, complete sterilization resulted after 6 hours. Cells irradiated with ultraviolet light were grown in complex or supplemental minimal media, washed, and exposed to 20 μg/ml of kanamycin in minimal medium for 4 hours. Auxotrophic mutants with requirements for tryptophane, phenylalanine, proline, and uracil were detected among the survivors of kanamycin treatment. After treatment with 0.01 M nitrous acid and growth in minimal medium supplemented with amino acids, cells were washed and then exposed to kanamycin in minimal medium. The proportion of autotrophs among the survivors varied from 1.3 to 75%. Mutants with requirements for each of the following amino acids were identified: methionine, methionine or cystine, arginine, leucine, tryptophane, histidme, and proline, with methionine-requiring mutants predominating. Exposure of mixtures of prototrophs and uracil-dependent and methionine-dependent auxotrophs to 20 μg/ml of kanamycin for 4 hours resulted in approximately 700- and 300-fold increases, respectively, in the ratio of auxotrophs to prototrophs.


Microbiology ◽  
2005 ◽  
Vol 151 (6) ◽  
pp. 1987-1994 ◽  
Author(s):  
Odile Juille ◽  
Dominique Le Bars ◽  
Vincent Juillard

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.


2010 ◽  
Vol 78 (5) ◽  
pp. 1841-1849 ◽  
Author(s):  
Olga Senkovich ◽  
Shantelle Ceaser ◽  
David J. McGee ◽  
Traci L. Testerman

ABSTRACT Helicobacter pylori chronically infects the gastric mucosa, where it can be found free in mucus, attached to cells, and intracellularly. H. pylori requires iron for growth, but the sources of iron used in vivo are unclear. In previous studies, the inability to culture H. pylori without serum made it difficult to determine which host iron sources might be used by H. pylori. Using iron-deficient, chemically defined medium, we determined that H. pylori can bind and extract iron from hemoglobin, transferrin, and lactoferrin. H. pylori can use both bovine and human versions of both lactoferrin and transferrin, contrary to previous reports. Unlike other pathogens, H. pylori preferentially binds the iron-free forms of transferrin and lactoferrin, which limits its ability to extract iron from normal serum, which is not iron saturated. This novel strategy may have evolved to permit limited growth in host tissue during persistent colonization while excessive injury or iron depletion is prevented.


Sign in / Sign up

Export Citation Format

Share Document