The influence of growth rate and growth-limiting factors on the production of ice nuclei inPseudomonas syringaeCCM 4073 in continuous culture

2000 ◽  
Vol 20 (3-4) ◽  
pp. 369-372
Author(s):  
B. Sikyta ◽  
J. Spilková ◽  
J. Dušek
1961 ◽  
Vol 7 (4) ◽  
pp. 491-505 ◽  
Author(s):  
Andreas H. W. Hauschild ◽  
Hilliard Pivnick

An apparatus is described for the continuous growth of bacteria. Brucella abortus S.19 has been grown in continuous culture for periods up to 3 weeks with populations up to 2 × 1011viable cells per ml and without the establishment of nonsmooth variants.Concentrations between 3 × 109and 2 × 1011cells per ml could be maintained as a function of the dilution rate without the requirement of a known limiting factor in the medium. In a series of steady-state conditions, the specific growth rate increased steadily up to 0.28 hour−1with decreasing population levels.Incidence of mutants was governed by the dilution rate and could also be reduced by various chelating substances.In continuous growth combined with continuous dialysis, population levels were approximately twice those obtained in continuous growth without dialysis. The effect of dialysis appears to be the continuous removal of growth-limiting metabolic products.


Genetics ◽  
1987 ◽  
Vol 116 (3) ◽  
pp. 349-358
Author(s):  
Robert B Helling ◽  
Christopher N Vargas ◽  
Julian Adams

ABSTRACT Populations of Escherichia coli, initiated with a single clone and maintained for long periods in glucose-limited continuous culture, developed extensive polymorphisms. In one population, examined after 765 generations, two majority and two minority types were identified. Stable mixed populations were reestablished from the isolated strains. Factors involved in the development of this polymorphism included differences in the maximum specific growth rate and in the transport of glucose, and excretion of metabolites by some clones which were utilized by minority clones.


2001 ◽  
Vol 664 ◽  
Author(s):  
M. Kondo ◽  
S. Suzuki ◽  
Y. Nasuno ◽  
A. Matsuda

ABSTRACTWe have developed a plasma enhanced chemical vapor deposition (PECVD) technique for high-rate growth of µc-Si:H at low temperatures using hydrogen diluted monosilane source gas under high-pressure depletion conditions. It was found that material qualities deteriorate, e.g. crystallinity decreases and defect density increases with increasing growth rate mainly due to ion damage from the plasma. We have found that deuterium dilution improves not only the crystallinity but also defect density as compared to hydrogen dilution and that deuterium to hydrogen ratio incorporated in the film has a good correlation with crystallinity. The advantages of the deuterium dilution are ascribed to lower ion bombardment due to slower ambipolar diffusion of deuterium ion from the plasma. Further improvement of material quality has been achieved using a triode technique where a mesh electrode inserted between cathode and anode electrodes prevents from ion bombardment. In combination with a shower head cathode, the triode technique remarkably improves the crystallinity as well as defect density at a high growth rate. As a consequence, we have succeeded to obtain much better crystallinity and uniformity at 5.8 nm/s with a defect density of 2.6×1016cm−3. We also discuss the limiting factors of growth rate and material quality for µc-Si solar cells.


Author(s):  
K. J. Jones ◽  
P. Tett ◽  
A. C. Wallis ◽  
B. J. B. Wood

Phytoplankton from Loch Creran, Argyll was maintained in continuous culture for 41 days. During most of this time the mixture of species retained the diversity and dominance pattern typical of summer phytoplankton in the loch, notwithstanding the manipulation of algal nutrient status to bring about phosphorus control of growth. Results suggest that most detritus was washed out early in the experiment.The aim of the experiment was to test the applicability to natural multispecies phytoplankton of part of Droop's (1974, 1975) model of nutrient-limited algal growth. ‘Quasi-steady states’ with respect to concentration of chlorophyll, particulate carbon (PC), particulate phosphorus (PP) and particulate nitrogen (PN), wereobserved at two levels of input of dissolved inorganic phosphorus. At other times the algal phosphorus quota (estimated from the ratio of PP to PC) varied from about 0·002 to 0·015 atoms P per atom C. Specific growth rate was estimated from the rate of increase of PC. During part of the experiment, growth rate was linearly related to reciprocal phosphorus quota, thus confirming the applicability of the model.


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