Induced Enzyme Synthesis in Aqueous Suspensions of Starved Stationary Phase Aerobacter Aerogenes

Nature ◽  
1961 ◽  
Vol 191 (4795) ◽  
pp. 1272-1273 ◽  
Author(s):  
R. E. STRANGE
Keyword(s):  
Stationary Phase ◽  
Enzyme Synthesis ◽  
Aerobacter Aerogenes ◽  
Aqueous Suspensions

scholarly journals Survival of virulentLegionella pneumophilain aerosols

1983 ◽  
Vol 90 (3) ◽  
pp. 451-460 ◽  
Author(s):  
P. Hambleton ◽  
M. G. Broster ◽  
P. J. Dennis ◽  
R. Henstridge ◽  
R. Fitzgeorge ◽  
...  
Keyword(s):  
Stationary Phase ◽  
Respiratory Disease ◽  
Legionella Pneumophila ◽  
Solid Medium ◽  
Exponential Phase ◽  
Metabolic Status ◽  
Aqueous Suspensions

SUMMARYAqueous suspensions of virulentLegionellapneumophilagrown on solid medium retained virulence and aerosol survival characteristics for several months. Significant numbers of viable organisms were recovered from aerosols held at various relative humidities (r.h.) for up to 2 h. The organisms survived best at 65% r.h. and were least stable at 55% r.h.Exponential phase broth-grown organisms survived poorly in aerosols in comparison with stationary phase broth cultures or organisms grown on solid medium, suggesting that the metabolic status ofLegionella pneumophilaorganisms may be an important factor affecting their ability to survive in aerosols and cause respiratory disease.

scholarly journals Pyruvate accumulation in growth-inhibited cultures of Aerobacter aerogenes

1968 ◽  
Vol 106 (2) ◽  
pp. 375-380 ◽  
Author(s):  
M. Webb
Keyword(s):  
Stationary Phase ◽  
Growth Inhibition ◽  
Exponential Growth ◽  
Glucose Utilization ◽  
Keto Acid ◽  
Aerobacter Aerogenes ◽  
Early Stages

1. Accumulation of pyruvate occurs during the early stages of exponential growth of aerobic, anaerobic and static cultures of a strain of Aerobacter aerogenes. In normal cultures of this organism the content of pyruvate increases until most of the glucose of the medium has been consumed, and then declines rapidly. The presence of unconsumed sugar is not the sole reason for the accumulation of keto acid, since this is unaffected by the addition of extra glucose to either exponentialphase or stationary-phase cultures. 2. In aminopterin-inhibited cultures, the rate of glucose utilization is decreased greatly, and pyruvate continues to accumulate throughout the period of incubation. This prolonged phase of accumulation appears to be a consequence of the growth inhibition, and not to a specific action of aminopterin on the phosphoroclastic breakdown of pyruvate, since it occurs also when growth is restricted by the antibiotics streptomycin, chloramphenicol and neomycin. 3. A possible explanation is suggested for the accumulation of pyruvate in the inhibited cultures.

GLUCOSE INHIBITION OF ASPARTASE SYNTHESIS BY AEROBACTER AEROGENES

1963 ◽  
Vol 9 (6) ◽  
pp. 835-842 ◽  
Author(s):  
Margaret A. Farley ◽  
Herman C. Lici-Istein
Keyword(s):  
Molecular Mechanism ◽  
Glucose Concentration ◽  
Glucose Repression ◽  
Enzyme Synthesis ◽  
Initial Glucose Concentration ◽  
Aerobacter Aerogenes ◽  
Complete Utilization ◽  
Glucose Inhibition ◽  
Lower Glucose ◽  
Suitable System

Studies were made comparing aspartase synthesis by Aerobacter aerogents grown in the presence and in the absence of glucose, and with or without agitation. It was observed that when a sufficient initial glucose concentration was employed, enzyme synthesis was not resumed to maximum levels even after complete utilization of the sugar. At a lower glucose concentration, however, synthesis did occur, suggesting that the specific repressor metabolite(s) produced from the glucose was not accumulated to inhibitory concentrations after the sugar was metabolized. A difference between stationary and aerobic (shaken) cultures was noted, perhaps affording a suitable system for investigating the molecular mechanism of glucose repression.

scholarly journals Biosynthesis of oxygen-detoxifying enzymes in Bdellovibrio stolpii

1982 ◽  
Vol 152 (2) ◽  
pp. 792-796
Author(s):  
R S Von Stein ◽  
L E Barber ◽  
H M Hassan
Keyword(s):  
Superoxide Dismutase ◽  
Stationary Phase ◽  
Protein Biosynthesis ◽  
Oxygen Toxicity ◽  
Enzyme Synthesis ◽  
Maximum Activity ◽  
Superoxide Dismutase Activity ◽  
Detoxifying Enzymes ◽  
Major Band ◽  
Kinetics Of

Axenically grown Bdellovibrio stolpii (i.e., grown independently of the host) was examined for superoxide dismutase, catalase, and peroxidase activities. Kinetics of enzyme synthesis were determined for aerobically grown cultures and for cultures exposed to 100% oxygen. Enzymatic activities varied with the age of the culture. Normally grown cultures exhibited maximum activity during the first 10 h of growth and again as the stationary phase was approached, beginning at about 48 h. Polyacrylamide gel electropherograms of cell-free extracts revealed that B. stolpii contained one major band (1) and two minor bands (II, III) of superoxide dismutase activity. Each of these enzymes was inactivated by H2O2, indicating that they were iron-containing enzymes. Manganese-containing superoxide dismutase was not detected in B. stolpii. Increased oxygenation did not appreciably stimulate enzyme synthesis, for only superoxide dismutase was induced, reaching maximum activity at 10 h and then rapidly falling to normal levels. Superoxide dismutase appears to be the main enzymatic defense against oxygen toxicity in B. stolpii. Induction of superoxide dismutase with 100% oxygen was manifested as an increase in the intensities of the two minor bands of activity, suggesting that isozyme I is constitutive, whereas isozymes II and III are inducible. The induction of isozymes II and III by 100% oxygen was prevented by an inhibitor of protein biosynthesis, chloramphenicol.

Morphological Characterization of Mycobacteriophage R1

1974 ◽  
Vol 32 ◽  
pp. 254-255
Author(s):  
B. L. Soloff ◽  
T. A. Rado
Keyword(s):  
Carbon Source ◽  
Stationary Phase ◽  
Growth Phase ◽  
Minimal Medium ◽  
Morphological Characterization ◽  
Logarithmic Growth Phase ◽  
Complete Lysis ◽  
Lysogenic Culture ◽  
Logarithmic Growth

Mycobacteriophage R1 was originally isolated from a lysogenic culture of M. butyricum. The virus was propagated on a leucine-requiring derivative of M. smegmatis, 607 leu−, isolated by nitrosoguanidine mutagenesis of typestrain ATCC 607. Growth was accomplished in a minimal medium containing glycerol and glucose as carbon source and enriched by the addition of 80 μg/ ml L-leucine. Bacteria in early logarithmic growth phase were infected with virus at a multiplicity of 5, and incubated with aeration for 8 hours. The partially lysed suspension was diluted 1:10 in growth medium and incubated for a further 8 hours. This permitted stationary phase cells to re-enter logarithmic growth and resulted in complete lysis of the culture.

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