Utilization of amino acids by Halobacterium cutirubrum in chemically defined medium

1972 ◽  
Vol 18 (8) ◽  
pp. 1349-1351 ◽  
Author(s):  
Louise Ducharme ◽  
A. T. Matheson ◽  
M. Yaguchi ◽  
L. P. Visentin

As part of a project involving the labeling of the ribosomal proteins of the extreme halophile Halobacterium cutirubrum with 14C-lysine, the chemically defined medium of Gochnauer and Kushner (2) was modified to allow maximal incorporation of 14C-lysine. The utilization of the other amino acids present in this medium was also measured. Of special interest was the rapid and complete disappearance of arginine from the medium before the beginning of log-phase growth.


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.



1983 ◽  
Vol 104 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Paul V. Holmes ◽  
Per O. Janson ◽  
Jan Sogn ◽  
Björn Källfelt ◽  
William J. LeMaire ◽  
...  

Abstract. Both ovaries of 31 rabbits were perfused with a chemically defined medium in vitro in a recirculation system. In one series of experiments, hCG (100 IU) was injected iv 5–6 h prior to anaesthesia and surgery. Approximately 1 h later the perfusion was started. One ovary was perfused as control while the other ovary was perfused with 5 μg/ml indomethacin or with indomethacin and 1 μg/ml PGF2α. In another series of experiments the rabbits received no pretreatment prior to operation. Instead, bovine LH was added to the perfusion medium of both control and experimental ovaries. The experimental side also received either indomethacin or indomethacin and PGF2α. Finally, the effect of PGF2α in the absence of LH was compared to the control ovary receiving only LH. After injection of hCG in vivo, ovulations occurred in 4 of 5 control ovaries. Indomethacin completely blocked ovulation in 4 of the 5 ovaries treated, while PGF2α restored ovulations in all the experimental ovaries. In the group of experiments where LH was added in vitro, ovulations were induced in all ovaries treated with varying LH doses. Furthermore, indomethacin blocked ovulation in 5 out of 7 ovaries, and PGF2α restored ovulation in all ovaries. Fifty per cent of the ovaries treated only with PGF2α (in the absence of LH) also ovulated. The pattern of steroid release did not differ between control ovaries, indomethacin treated ovaries, and indomethacin + PGF2α treated ovaries. Ovaries treated in perfusion with PGF2α alone had very low steroid levels compared to the ovaries treated with LH. This study confirms that indomethacin blocks ovulation in the perfused rabbit ovary and that this blockade can be overcome by exogenous PGF2α. Indomethacin and PG-treatments after ovulation induction did not affect ovarian steroidogenesis. Furthermore, while PGF2α was able to induce ovulations in these perfused oestrous ovaries in the absence of LH, it did not stimulate steroidogenesis.





1961 ◽  
Vol 14 (3) ◽  
pp. 349 ◽  
Author(s):  
FJ Bergersen

A chemically defined medium for the growth of Rhizobium is described in which populations of up to 5 x 109 cells/ml were obtained. For the six strains of bacteria studied the complete medium supported exponential growth for two to five generations. The concentrations of biotin giving best growth varied ith strain between 125 and 250 f'g/l when the nitrogen source was sodium glutamate. NHt, NOs, and other amino acids, singly or in combination, did not upport as good growth as did sodium glutamate.



1994 ◽  
Vol 26 (2) ◽  
pp. 301-303 ◽  
Author(s):  
B. Rodelas ◽  
V. Salmeron ◽  
M.V. Martinez-Toledo ◽  
J. Gonzalez-Lopez


1975 ◽  
Vol 53 (12) ◽  
pp. 1323-1327 ◽  
Author(s):  
Alastair T. Matheson ◽  
Makoto Yaguchi ◽  
Louis P. Visentin

Alanine, methionine, and serine are the predominant N-terminal residues in the cytosol and ribosomal protein fractions from the thermophile Bacillus stearothermophilus and the extreme halophile Halobacterium cutirubrum, a similar situation to that previously found in Escherichia coli. In all three bacteria the N-terminal residues of the 30S ribosomal proteins are mainly alanine [Formula: see text] methionine > serine whereas in the 50S ribosomal proteins from E. coli and B. stearothermophilus the predominant residues are methionine > alanine > serine suggesting conservation of specific N-terminal residues in these ribosomal proteins. However, the 50S ribosomal proteins from H. cutirubrum showed serine as the major N-terminal residue.



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.



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