Growth of suspension cultures of plant cells (Ipomoea sp.) at various temperatures

1975 ◽  
Vol 53 (4) ◽  
pp. 315-320 ◽  
Author(s):  
Dyson Rose ◽  
S. M. Martin
Keyword(s):  
Growth Rate ◽  
Suspension Culture ◽  
Cell Line ◽  
Plant Cells ◽  
Maximum Growth ◽  
Suspension Cultures ◽  
Root Explants ◽  
Temperature Variations ◽  
Satisfactory Method ◽  
Dry Cell

Studies on the growth of batch suspension cultures of a plant cell line, initiated from Ipomoea sp. root explants, at temperatures ranging from 15 to 34 °C are reported. Maximum growth of cultures of this cell line occurred between 25 and 32 °C, with temperature variations within this range having little effect on growth rates based on dry cell yields. Cultivation at 20 °C substantially reduced the growth rate. However, cells grown at 20 °C failed to grow on transfer to fresh medium at 20 °C. Thus cultivation at suboptimum temperatures is not a satisfactory method for routine maintenance of the suspension culture.

scholarly journals THE KINETICS BOTH OF GROWTH AND METABOLITE PRODUCTION OF X.CAMPESTRIS USING OF 4% LIQUID SUGAR SUBSTRATE FROM CASSAVA HYDROLISATE

2017 ◽  
Vol 6 (1) ◽  
pp. 45-49
Author(s):  
Nancy Siti Djenar ◽  
Edi Wahyu Sri Mulyono
Keyword(s):  
Growth Rate ◽  
Xanthan Gum ◽  
Maximum Growth ◽  
Process Conditions ◽  
Metabolite Production ◽  
Method Of Calculation ◽  
Cell Weight ◽  
Dry Cell Weight ◽  
Kinetics Of ◽  
Dry Cell

X. campestris is aerobic bacteria producing extracellular biopolymers (EPS, extracellular polysaccharide) known as xanthan gum. To determine the technology and the process conditions appropriate to the formation of this product, therefore the understanding of both the kinetics of growth and metabolite production of bacteria is needed. In this research, to assess the growth of X. campestris using the method of calculation of dry cell weight. For determining the kinetics of production of metabolite used substrates of 4% liquid sugar from cassava starch hydrolysate. From this research was showed that X. campestris maximum growth in NB medium obtained in about 58thhour, at the growth rate of about 0.04 g / hour, stationary phase obtained at the 60th hour with a maximum dry cell weight of 2.7688 g/L and specific growth rate (?) of X. campestris amounted to 0.043 hour-1. Based on the kinetic curves both on growth and its metabolite production, X.campestris has non-growth associated product pattern. In this case the production of xanthan gum occured after cell growth stopped then its product is a secondary metabolite with highest amount of 3.73 g / L at 102nd hour, ie the 4th day of fermentation. Overall of this research indicated that Nutrient Broth (NB) may be used for the growth of X. campestris. But based on the value of ? above, the rate of cell reproduction was still low. Liquid sugar can be used as a substrate to produce xanthan gum. However to increase its productivity, there should be an addition of other carbon or energy and nitrogen sources.

Uptake of magnesium by suspension cultures of plant cells (Ipomoea sp.)

1977 ◽  
Vol 55 (9) ◽  
pp. 1143-1147 ◽  
Author(s):  
I. A. Veliky ◽  
D. Rose ◽  
M. W. Zink
Keyword(s):  
Cell Line ◽  
Plant Cells ◽  
Suspension Cultures ◽  
Magnesium Level ◽  
Morning Glory ◽  
Distilled Water ◽  
High Ph

The magnesium level required to support full growth in batch suspension cultures of an Ipomoea sp. (Morning Glory) cell line in 2% sucrose media was less than 0.3 mM. The uptake of magnesium increased with increasing magnesium in the medium, and with increasing pH at constant magnesium level. In medium containing 1.0 mM (24 mg/ℓ) magnesium, a culture kept at pH 4.7 absorbed 6 mg of magnesium in 150 h; the corresponding figure for a culture kept at pH 6.9 was 19 mg.Much of the excess magnesium taken up by cells grown at the 1.0 mM magnesium level at various controlled pH levels could be extracted by grinding the cells in distilled water. The data suggest that under conditions of high magnesium supply and high pH these cells absorb large amounts (i.e. several milligrams per gram dry cells) of magnesium in excess of their requirement for growth.

Saturation mechanism and generated viscosity in gravito-turbulent accretion disks

2020 ◽  
Vol 640 ◽  
pp. A53
Author(s):  
L. Löhnert ◽  
S. Krätschmer ◽  
A. G. Peeters
Keyword(s):  
Growth Rate ◽  
Numerical Simulations ◽  
Accretion Disks ◽  
Gravitational Instability ◽  
Turbulent Viscosity ◽  
Radial Distance ◽  
Maximum Growth ◽  
Wave Number ◽  
Radiative Cooling ◽  
Mixing Length

Here, we address the turbulent dynamics of the gravitational instability in accretion disks, retaining both radiative cooling and irradiation. Due to radiative cooling, the disk is unstable for all values of the Toomre parameter, and an accurate estimate of the maximum growth rate is derived analytically. A detailed study of the turbulent spectra shows a rapid decay with an azimuthal wave number stronger than ky−3, whereas the spectrum is more broad in the radial direction and shows a scaling in the range kx−3 to kx−2. The radial component of the radial velocity profile consists of a superposition of shocks of different heights, and is similar to that found in Burgers’ turbulence. Assuming saturation occurs through nonlinear wave steepening leading to shock formation, we developed a mixing-length model in which the typical length scale is related to the average radial distance between shocks. Furthermore, since the numerical simulations show that linear drive is necessary in order to sustain turbulence, we used the growth rate of the most unstable mode to estimate the typical timescale. The mixing-length model that was obtained agrees well with numerical simulations. The model gives an analytic expression for the turbulent viscosity as a function of the Toomre parameter and cooling time. It predicts that relevant values of α = 10−3 can be obtained in disks that have a Toomre parameter as high as Q ≈ 10.

A note on growth curves of rabbit lines selected on growth rate or litter size

1993 ◽  
Vol 57 (2) ◽  
pp. 332-334 ◽  
Author(s):  
A. Blasco ◽  
E. Gómez
Keyword(s):  
Growth Rate ◽  
Litter Size ◽  
Growth Curves ◽  
Live Weight ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Standard Errors ◽  
Adult Weight ◽  
Weight Growth ◽  
Using Data

Two synthetic lines of rabbits were used in the experiment. Line V, selected on litter size, and line R, selected on growth rate. Ninety-six animals were randomly collected from 48 litters, taking a male and a female each time. Richards and Gompertz growth curves were fitted. Sexual dimorphism appeared in the line V but not in the R. Values for b and k were similar in all curves. Maximum growth rate took place in weeks 7 to 8. A break due to weaning could be observed in weeks 4 to 5. Although there is a remarkable similarity of the values of all the parameters using data from the first 20 weeks only, the higher standard errors on adult weight would make 30 weeks the preferable time to take data for live-weight growth curves.

Accumulation of phytoalexins in the compatible interaction between Cladosporium fulvum and tomato in relation to colonization

1991 ◽  
Vol 69 (4) ◽  
pp. 822-830 ◽  
Author(s):  
Ulisses G. Batista ◽  
Verna J. Higgins
Keyword(s):  
Suspension Culture ◽  
Germ Tube ◽  
Plant Cells ◽  
Cladosporium Fulvum ◽  
In Vitro Experiments ◽  
Compatible Interaction ◽  
Leaf Mold ◽  
Production And Distribution ◽  
Fulvia Fulva

The production and distribution of the phytoalexin falcarindiol in tomato foliage infected with leaf mold was examined to determine how the fungus Cladosporium fulvum is able to colonize and sporulate in an apparently antifungal environment. In a compatible interaction (cv. Potentate – C. fulvum race 2.3), by 12 and 15 days after inoculation, solvent-extractable falcarindiol and two other phytoalexins from tomato, compound 2 (probably falcarinol) and compound 3 (unidentified), reached concentrations considerably in excess of ED50 values for inhibition of the fungus. In contrast, intercellular (apoplastic) fluids obtained from similarly infected leaflets contained only traces of falcarindiol. ED50 values for germination and germ-tube growth of C. fulvum increased as the incubation time was extended, suggesting that adaptation or recovery was possible at the concentrations tested. In in vitro experiments, C. fulvum appeared to readily metabolize falcarindiol, as did a Lycopersicon cell suspension culture. Binding of falcarindiol to living and dead fungal and plant cells was also observed. Falcarindiol, injected into tomato leaflets, decreased rapidly and was only recovered in trace amounts by 24 h. The results suggest that falcarindiol and probably the two other phytoalexins do not reach sufficient concentrations in the apoplast of an infected susceptible leaf to have an effect on growth and sporulation of C. fulvum. Key words: leaf mold, Fulvia fulva, falcarindiol, falcarinol.

Reassessment of Maximum Growth Rates for C3 and C4 Crops

1978 ◽  
Vol 14 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. L. Monteith
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growing Season ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Crop Growth ◽  
Close Inspection ◽  
Similar Difference ◽  
Photosynthetic Efficiencies

SUMMARYFigures for maximum crop growth rates, reviewed by Gifford (1974), suggest that the productivity of C3 and C4 species is almost indistinguishable. However, close inspection of these figures at source and correspondence with several authors revealed a number of errors. When all unreliable figures were discarded, the maximum growth rate for C3 stands fell in the range 34–39 g m−2 d−1 compared with 50–54 g m−2 d−1 for C4 stands. Maximum growth rates averaged over the whole growing season showed a similar difference: 13 g m−2 d−1 for C3 and 22 g m−2 d−1 for C4. These figures correspond to photosynthetic efficiencies of approximately 1·4 and 2·0%.

scholarly journals Growth of GaN from elemental Gallium and Ammonia via Modified Sandwich Growth Technique

2004 ◽  
Vol 831 ◽  
Author(s):  
E. Berkman ◽  
R. Collazo ◽  
R. Schlesser ◽  
Z. Sitar
Keyword(s):  
Growth Rate ◽  
Gas Flow ◽  
Transport Model ◽  
Theoretical Calculations ◽  
Substrate Surface ◽  
Maximum Growth ◽  
Direct Reaction ◽  
Pure Nitrogen ◽  
Flow Rates ◽  
Reactor Pressure

ABSTRACTGallium nitride (GaN) films were grown on (0001) sapphire substrates at 1050°C by controlled evaporation of gallium (Ga) metal and reaction with ammonia (NH3) at a total reactor pressure of 800 Torr. Pure nitrogen (N2) was flowed directly above the molten Ga source to prevented direct reaction between the molten Ga and ammonia, which causes Ga spattering and GaN crust formation. At the same time, this substantially enhanced the Ga transport to the substrate. A simple mass-transport model based on total reactor pressure, gas flow rates and source temperature was developed and verified. The theoretical calculations and growth rate measurements at different ammonia flow rates and reactor pressures showed that the maximum growth rate was controlled by transport of both Ga species and reactive ammonia to the substrate surface.

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