Dependence Of Specific Growth Rate Research Articles

Non-linear analysis of Haldane kinetic model in phenol degradation in batch operations

The Haldane kinetic model of phenol biodegradation in batch operation is discussed. This kinetic is most commonly used to describe the dependence of specific growth rate on the concentration of an inhibition substrate. Analytical expressions for the concentration of biomass and substrate are presented using new approach to the homotopy perturbation method. Our results are compared with the experimental data for all values of parameters.

An approach to the rapid control of oil spill bioremediation by bioluminescent method of intracellular ATP determination

Control of oil hydrocarbon biodegradation by enumeration of oil-degrading cells was demonstrated using the bioluminescence method of intracellular ATP determination. The method was used in enumerating hydrocarbon-oxidizing bacteria in soil containing various concentrations of oil (up to 60% oil w/w) and cells (2.7 � 10 4 � 3.9 � 10 7 cell g � 1 ). Investigation of the growth kinetics of Rhodococcus ruber and Pseudomonas putida in the oil-contaminated soil revealed the dependence of specific growth rate on the initial pollutant concentration. The results of the bioluminescence method correlated with levels of oil biodegradation determined gravimetrically. The apparent synergistic effect demonstrated between two cultures was verified by the bioluminescence and gravimetric methods and growth kinetics data. The same approach was used to estimate the presence of indigenous microbiota in oil-contaminated soil samples taken from the oilfields of Baku region (Azerbaijan). The total ATP level detected revealed an inverse negative relationship with oil concentration in the sample. The bioluminescence method of intracellular ATP determination could be widelyused to estimate the efficacyof application of hy drocarbon-oxidizing bacteria in the decontamination processes. r 2005 Elsevier Ltd. All rights reserved.

Kinetic analysis of the effect of cell density on hybridoma cell growth in batch culture

The effect of cell density on cell growth was investigated in a suspension batch culture of hybridoma cells. The specific growth rate was found to increase with increasing initial cell density and then to decrease with further increases in initial cell density. In order to quantitatively describe the dependence of specific growth rate on cell density, a kinetic model is proposed, which satisfactorily represents the experimental data.

Intracellular phosphorus pool of the cyanobacteriumSpirulina platensis

An intracellular phosphorus pool in a monoculture of the cyanobacteriumSpirulina platensis was assessed using radioactive and nonradioactive phosphorus. The derived dependence of specific growth rate on the intracellular content of mineral phosphorus can be presented in the form of the Droop equation. It was found that the stage of replenishment of the intracellular phosphorus pool may affect the phosphorus turnover estimation in aquatic environments from the results of short-term measurements of phosphorus uptake

Interrelationships Between Prey Body Size and Growth of Age-0 Yellow Perch

Abstract We conducted laboratory experiments in the summers of 1986 and 1987 to examine the effects of Daphnia pulex body size and ration level on growth of age-0 yellow perch Perca flavescens. Daphnia pulex rations were set at 25 and 40% of yellow perch dry weight. Specific growth rate tended to be higher for smaller fish and decreased with fish size at both ration levels. For the 25% ration, the highest growth rates, 0.023 to 0.024 g/d, were observed when yellow perch were fed meals of D. pulex between 1.4 and 1.8 mm long; growth declined for prey sizes outside this size range. For the 40% ration, no relationship was found between body length of D. pulex and specific growth rate; the mean specific growth rate for the 40% ration was the same as the peak rate for the 25% ration. Multiple-regression analysis was used to examine the dependence of specific growth rate of yellow perch on initial fish length, prey size, and temperature. For the 25% ration, prey size and the square of prey size were the only va...

Interaction of Combined Nitrogen Availability and Light in the Regulation of Growth, Heterocyst Differentiation and Dinitrogen Fixation of the Planktic Blue-Green Alga Anabaena solitariaKleb.

Dependence of specific growth rate of the planktic blue-green alga Anabaena solitaria on light intensity (continuous light) was described using modified Mitscherlich-equation. Deficiency of combined nitrogen does not remarkably influence either maximum specific growth rate or parameters of light utilization efficiency (i 0, k I). Growth rates at any light intensities are lower by only 10% if only elemental N 2 is available. Whereas nitrogenase activity is suppressed by ammonium nitrate supply to a very low level, heterocysts are still present under the same conditions. The results are discussed with respect to the adaptability of A. solitaria to changing but limiting nitrogen supply.

Molar Growth Yields of Yeasts in Anaerobic Batch Cultures

An intracellular phosphorus pool in a monoculture of the cyanobacterium Spirulina platensis was assessed using radioactive and nonradioactive phosphorus. The derived dependence of specific growth rate on the intracellular content of mineral phosphorus can be presented in the form of the Droop equation. It was found that the stage of replenishment of the intracellular phosphorus pool may affect the phosphorus turnover estimation in aquatic environments from the results of short-term measurements of phosphorus uptake.