scholarly journals The Growth Of Rhizobium in Synthetic Media

1961 ◽  
Vol 14 (3) ◽  
pp. 349 ◽  
Author(s):  
FJ Bergersen
Keyword(s):  
Amino Acids ◽  
Nitrogen Source ◽  
Exponential Growth ◽  
Defined Medium ◽  
Complete Medium ◽  
Good Growth ◽  
Chemically Defined Medium ◽  
Sodium Glutamate ◽  
Synthetic Media

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.

scholarly journals Enhancement of Exopolysaccharide Production byLactobacillus delbrueckii subsp. bulgaricus NCFB 2772 with a Simplified Defined Medium

1998 ◽  
Vol 64 (4) ◽  
pp. 1333-1337 ◽  
Author(s):  
G. J. Grobben ◽  
I. Chin-Joe ◽  
V. A. Kitzen ◽  
I. C. Boels ◽  
F. Boer ◽  
...  
Keyword(s):  
Amino Acids ◽  
Defined Medium ◽  
Complete Loss ◽  
Lactobacillus Delbrueckii ◽  
Complete Medium ◽  
Calcium Pantothenate ◽  
Chemically Defined Medium ◽  
Batch Cultures ◽  
Exopolysaccharide Production ◽  
Medium Components

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.

Physiology of two monocentric chytrids: comparative nutritional studies of Entophlyctis sp. and Entophlyctis aureus (Chytridiales)

2000 ◽  
Vol 78 (1) ◽  
pp. 105-109 ◽  
Author(s):  
Mozaffar W Hassan ◽  
Edward J Catapane
Keyword(s):  
Amino Acids ◽  
Nitrate Nitrogen ◽  
Defined Medium ◽  
Physiological Characteristics ◽  
Good Growth ◽  
Chemically Defined Medium ◽  
Vitamin Requirements ◽  
Nutritional Studies ◽  
Vitamin Mixture ◽  
Nutrient Solutions

This paper describes physiological characteristics of Entophlyctis sp. and Entophlyctis aureus Fisher. The two chytrids grew best at 20-25°C in a chemically defined medium, and at 20-30°C in nutrient solutions containing bactotryptone and glucose. The range of pH that supported good growth was 6.5-8.5. Both organisms utilized ammonium and nitrate nitrogen, several amino acids, and glucose, fructose, mannose, maltose, and raffinose. They were prototrophic with respect to vitamin requirements, and vitamin mixture at a concentration of 10 µg/mL inhibited growth. They are physiologically similar to Entophlyctis confervae-glomeratae (Cienkowski) Sparrow.Key words: Entophlyctis sp., Entophlyctis aureus, Entophlyctis confervae-glomeratae.

CHEMICALLY DEFINED MEDIUM FOR GROWTH OF MICROCOCCUS LYSODEIKTICUS

1961 ◽  
Vol 7 (1) ◽  
pp. 27-32 ◽  
Author(s):  
E. A. Grula ◽  
Shing-kei Luk ◽  
Yung-chieh Chu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Defined Medium ◽  
Good Growth ◽  
Chemically Defined Medium ◽  
Free Base ◽  
Specific Amino Acid ◽  
Absolute Requirement ◽  
Adenylic Acid ◽  
Amino Acid Requirements

A chemically defined medium for growth of M. lysodeikticus is presented. The organism possesses a relatively nonspecific but absolute purine requirement that can best be satisfied by the free base hypoxanthine although adenine also allows some growth. A substitution for hypoxanthine, however, can be made by inosine, adenosine, or adenylic acid, but not by guanosine or guanylic acid. Although biotin stimulates growth, equally good growth occurs using biocytin or biotiu-d-sulphoxide. Less stimulation is apparent using desthiobiotin, dl-oxybiotin, or biotirt-l-sulphoxide. Although amino acids are necessary for growth, no absolute requirement for a specific amino acid can be demonstrated. The amino acid requirements need to be defined in terms of those amino acids which support good growth in the presence or absence of glutamic acid.

QUALITATIVE STUDIES OF SOIL MICROORGANISMS: IX. AMINO ACID REQUIREMENTS OF RHIZOSPHERE BACTERIA

1950 ◽  
Vol 28c (1) ◽  
pp. 1-6 ◽  
Author(s):  
R. H. Wallace ◽  
A. G. Lochhead
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Soil Microorganisms ◽  
Maximum Growth ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Special Significance ◽  
Specific Amino Acid ◽  
Pronounced Decrease ◽  
Amino Acid Requirements

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.

USE OF KANAMYCIN FOR THE ISOLATION OF AUXOTROPHIC MUTANTS OF ACTINOBACILLUS MALLEI

1966 ◽  
Vol 12 (4) ◽  
pp. 641-652 ◽  
Author(s):  
D. H. Evans
Keyword(s):  
Amino Acids ◽  
Nitrous Acid ◽  
Minimal Medium ◽  
Inhibitory Concentration ◽  
Bactericidal Effect ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Auxotrophic Mutants ◽  
Viable Cells ◽  
Minimal Media

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.

Nutritional requirements for cell wall synthesis in Micrococcus lysodeikticus

1969 ◽  
Vol 15 (4) ◽  
pp. 327-334
Author(s):  
M. P. Hatton
Keyword(s):  
Amino Acids ◽  
Cell Wall ◽  
Glutamic Acid ◽  
Dry Weight ◽  
Defined Medium ◽  
Complete Medium ◽  
Magnesium Ions ◽  
Cell Wall Synthesis ◽  
Micrococcus Lysodeikticus ◽  
Total Dry Weight

Preferential cell wall synthesis in Micrococcus lysodeikticus, as determined by an increase in the dry weight of the cell wall, took place in a medium containing DL-glutamic acid, DL-alanine, L-lysine, glycine, magnesium ions, glucose and phosphate buffer, pH 7.0. Cell wall synthesis could not be completely dissociated from protein synthesis in the 'cell wall' medium. The cell wall synthesized in the defined medium accounted for 40–56% of the total dry weight increase of the cells. Chloramphenicol had no effect on cell wall synthesis. Incorporation of uracil and guanine in the medium did not result in any increase in the amount of cell wall synthesized. DL-Glutamic acid alone, or a mixture of the three amino acids DL-alanine, L-lysine, and glycine, were capable of replacing the four amino acids present in the complete medium, but under these conditions the total dry weight of cell wall synthesized was only 75% of that produced in the complete medium. There was no reduction in cell wall synthesis when L-glutamic acid replaced DL-glutamic acid, L-alanine replaced DL-alanine, or sucrose replaced glucose in the cell wall medium. Deprivation of magnesium ions produced the greatest decrease in wall synthesis; this was the most important single factor involved in cell wall synthesis which was studied in the present investigation. There was no observable change in the chemical composition of the cell wall synthesized in the 'wall' medium when compared to that synthesized by cells grown in a complex medium.

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.

Nitrogen source regulates expression of alanine dehydrogenase isoenzymes in Streptomyces avermitilis in a chemically defined medium

1997 ◽  
Vol 43 (2) ◽  
pp. 189-193 ◽  
Author(s):  
Jan Novák ◽  
Jan Kopecký ◽  
Zdenko Vaněk
Keyword(s):  
Nitrogen Source ◽  
Ammonium Sulfate ◽  
Alanine Aminotransferase ◽  
Specific Activity ◽  
Defined Medium ◽  
Streptomyces Avermitilis ◽  
Chemically Defined Medium ◽  
Ammonium Ions ◽  
Alanine Dehydrogenase ◽  
Dehydrogenase Reaction

Ammonium ions and alanine influence production of the macrolide avermectin in Streptomyces avermitilis. L-Alanine dehydrogenase and alanine aminotransferase are the primary enzymes responsible for regulating the intracellular concentration of alanine and also of ammonium ions. In cultures of S. avermitilis in a chemically defined medium with ammonia or L-alanine as the only nitrogen source, specific activities of both enzymes increased during growth. The alanine dehydrogenase specific activity increased more than 86-fold after the culture was supplemented with 0.2% L-alanine and 5-fold after addition of 0.5% ammonium sulfate, whereas alanine aminotransferase specific activity increased 3- to 4-fold with either substrate. Five isoenzymes of alanine dehydrogenase were detected histochemically in S. avermitilis after native gel electrophoresis. Isoenzyme 1 was induced by alanine and temporarily repressed by high concentrations of ammonium sulfate. The presence of isoenzyme 1 was also related to changes in the kinetic properties of the alanine dehydrogenase reaction measured in crude desalted extracts. A nonlinear double-reciprocal plot was obtained in initial velocity studies using L-alanine as a substrate in the sample induced with L-alanine. The nonlinearity was caused by both substrate inhibition and allosteric regulation (positive cooperativity) by L-alanine. In contrast, the sample induced by ammonium sulfate showed a linear double-reciprocal plot.Key words: isoenzymes, L-alanine dehydrogenase, Streptomyces avermitilis, avermectin.

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