Extracellular Secondary Metabolite Production by the Marine Dinoflagellate Prorocentrum minimum in Culture

1981 ◽  
Vol 38 (7) ◽  
pp. 864-867 ◽  
Author(s):  
Charles G. Trick ◽  
Paul J. Harrison ◽  
Raymond J. Andersen
Keyword(s):  
Cell Division ◽  
Secondary Metabolite ◽  
Exponential Growth ◽  
Growth Period ◽  
Phosphate Starvation ◽  
Bacterial Toxins ◽  
Prorocentrum Minimum ◽  
Batch Cultures ◽  
Marine Dinoflagellate ◽  
Marine Dinoflagellates

Marine dinoflagellates produce extracellular secondary metabolites that may play a role in the ecology of the producing species. The concentration of one such external metabolite, 1-(2,6,6-trimethyl-4-hydroxycyclohexenyl)-1, 3-butanedione, produced by the marine dinoflagellate Prorocentrum minimum, was determined quantitatively during exponential growth and during senescence in phosphate-starved batch cultures. The pattern of production is similar to the production of many bacterial toxins. There was little production of the β-diketone during the exponential growth period and highest production occurred within 1 wk after cessation of cell division. About 50% of the total β-diketone produced was excreted on a single day, 6 d after phosphate became limiting to growth. Cell lysis or photodestruction of carotenoids do not appear to be the source of this compound.Key words: antibiotic, dinoflagellate, organic excretion, Prorocentrum minimum, secondary metabolite, phosphate starvation

ABNORMAL GROWTH INDUCED BY PENICILLIN IN A STRAIN OF ALCALIGENES FECALIS

1958 ◽  
Vol 4 (2) ◽  
pp. 165-177 ◽  
Author(s):  
K. G. Lark
Keyword(s):  
Cell Wall ◽  
Cell Division ◽  
Exponential Growth ◽  
Division Rate ◽  
Abnormal Growth ◽  
Globular Form ◽  
Kinetics Of

The effect of penicillin on strain LB of Alcaligenes fccalis has been studied. In tryptone, 50 units/ml. of penicillin transforms the bacillary form of this organism into a protoplast-like structure (globular form) which is capable of exponential growth and division. The division rate of this globular form is about one-half that of the bacillary form. Removal of penicillin results in the reversion of the globular to the bacillary form. Multiplication of the globular form has been found to depend on the presence of some principle present in tryptone not required for bacillary growth in the absence of penicillin. The kinetics of the transformation and reversion process have been studied, leading to the hypothesis that penicillin affects some component: within the cell, this component being concerned with cell division and the elaboration of the cell wall.

Exponential growth phase ofPseudomonas methanolica batch cultures

1973 ◽  
Vol 13 (6) ◽  
pp. 523-528 ◽  
Author(s):  
E. M. Shulgovskaya ◽  
I. I. Ivanova ◽  
G. G. Sotnicov
Keyword(s):  
Growth Phase ◽  
Exponential Growth ◽  
Exponential Growth Phase ◽  
Batch Cultures

Parameters for growth measurement in suspension cultures of plant cells

1974 ◽  
Vol 52 (4) ◽  
pp. 903-912 ◽  
Author(s):  
Dyson Rose ◽  
S. M. Martin
Keyword(s):  
Stationary Phases ◽  
Plant Cells ◽  
Growth Period ◽  
Dry Weight ◽  
High Rate ◽  
Growth Phases ◽  
Batch Cultures ◽  
Growth Measurement ◽  
Large Increments ◽  
Uptake And Metabolism

Well-adapted cells, which had been initiated from root tissue of Ipomoea and of Daucus carota, were grown in 7.5-liter stirred-jar fermenters, and both the cells and media were analyzed for major components at intervals during the growth period. Controlled variables included the size of inoculum, the amount of sucrose, and the source and amount of nitrogen in the media.The data obtained indicate that there are two distinct growth phases in the development of batch cultures of these cell lines. The first, which we term "cytoplasmic growth phase," begins immediately upon addition of inoculum to fresh medium and is characterized by a high rate of nitrogen uptake and metabolism relative to the increase in cell dry weight. The second, or "maturation phase," is characterized by large increments in dry weight and total cell carbohydrate relative to the increments in cell nitrogen. It is suggested that the classical lag, log, and stationary phases of bacterial growth could apply only to the early hours of cytoplasmic growth, if indeed they are relevant at all.

scholarly journals Effects of food concentration and diet on chromophoric dissolved organic matter accumulation and fluorescent composition during grazing experiments with the copepod Calanus finmarchicus

2004 ◽  
Vol 61 (4) ◽  
pp. 542-551 ◽  
Author(s):  
Juanita Urban-Rich ◽  
James T McCarty ◽  
Mark Shailer
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Exponential Growth ◽  
Life Stage ◽  
Food Concentration ◽  
Prorocentrum Minimum ◽  
Calanus Finmarchicus ◽  
Food Type ◽  
Chromophoric Dissolved Organic Matter ◽  
Effects Of Food Concentration

AbstractLaboratory experiments were conducted with Calanus finmarchicus copepodites IV–V to examine the effects of food concentration, food type, and life stage on chromophoric dissolved organic matter (CDOM) release from copepods. Changes in CDOM absorption and fluorescence were monitored by incubating copepods in rotating bottles for 24 h in the dark with controlled diets. Copepods were fed a range of food concentrations from 800 to 15 000 cells l−1 of either Thalassiosira weissflogii and Skeletonema costatum or Prorocentrum minimum in stationary and exponential growth phases. Results from these studies indicate that diet does have an effect on the amount and type of CDOM released by C. finmarchicus. A diet of either diatoms or dinoflagellates in exponential growth will result in a release of humic-like material, while feeding on senescent cells leads to a net input of protein-like material. Only at very high senescent cell concentrations (>5000 cells l−1) can humic-like material accumulate. This could lead to seasonal cycles in the amount and type of CDOM released by copepods, such that humic-like material will be released in the spring and at the height of phytoplankton blooms, while protein-like material will be added to the water as the bloom dies. The humic-like material found in these studies is blue-shifted compared to the standard humic material (Peaks A, M, and C) measured in seawater. The role of this humic-like material in the environment is currently unknown, but it could be important in absorbing UV radiation.

scholarly journals Fission Yeast Cells Grow Approximately Exponentially

2018 ◽  
Author(s):  
Mary Pickering ◽  
Lauren Nicole Hollis ◽  
Edridge D’Souza ◽  
Nicholas Rhind
Keyword(s):  
Cell Cycle ◽  
Cell Growth ◽  
Fission Yeast ◽  
Cell Size ◽  
Exponential Growth ◽  
Cell Biology ◽  
Growth Models ◽  
Growth Period ◽  
Yeast Cells ◽  
Yeast Growth

ABSTRACTHow the rate of cell growth is influenced by cell size is a fundamental question of cell biology. The simple model that cell growth is proportional to cell size, based on the proposition that larger cells have proportionally greater synthetic capacity than smaller cells, leads to the predication that the rate of cell growth increases exponentially with cell size. However, other modes of cell growth, including bilinear growth, have been reported. The distinction between exponential and bilinear growth has been explored in particular detail in the fission yeast Schizosaccharomyces pombe. We have revisited the mode of fission yeast cell growth using high-resolution time-lapse microscopy and find, as previously reported, that these two growth models are difficult to distinguish both because of the similarity in shapes between exponential and bilinear curves over the two-fold change in length of a normal cell cycle and because of the substantial biological and experimental noise inherent to these experiments. Therefore, we contrived to have cells grow more than two fold, by holding them in G2 for up to eight hours. Over this extended growth period, in which cells grow up to 5.5-fold, the two growth models diverge to the point that we can confidently exclude bilinear growth as a general model for fission yeast growth. Although the growth we observe is clearly more complicated than predicted by simple exponential growth, we find that exponential growth is a robust approximation of fission yeast growth, both during an unperturbed cell cycle and during extended periods of growth.

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