共查询到20条相似文献,搜索用时 78 毫秒
1.
Summary The oxygen requirement ofHansenula
anomala growing in batch culture on nitrate as sole source of nitrogen was examined. An aeration rate of 0.03 vvm or a constant oxygen partial pressure of 0.01 bar is sufficient for optimal growth. 相似文献
2.
Summary The effect of the physical (hydrodynamic) stress generated by aeration and agitation in suspension cultures onCatharanthus
roseus cells was studied. The intensity of the physical stress was closely related to the growth rate of the cells, the maximum cell mass, the size distribution of cell aggregates, the contents of the cell wall, and each component of the cell wall. 相似文献
3.
Alastair T. King John Bray Bernard J. Mulligan Kenneth C. Lowe 《Biotechnology Techniques》1990,4(3):195-200
Summary The effects of various perfluorochemical (PFC) oils on growth and structure of microbial and plant cell cultures have been studied. Growth of microbial cells was unaffected by culture with PFCs and no obvious deleterious effects on cell structure or alterations in polypeptide profiles of cell extracts were observed. Incubation of S. dulcamara cells with FDC oil produced an increase in culture growth rate, as measured by changes in wet and dry cell weights, probably by providing protection against hydrodynamic damage. 相似文献
4.
Summary Enhanced rates of ethanol production byPachysolen tannophilus from D-xylose were obtained by performing the fermentation with recycled cells in suspension culture or immobilized in a Ca-alginate gel. Fermentation under these conditions did not require aeration. Increasing temperature from 30 to 37°C enhanced the amount of ethanol produced in 24 hours from the recycled or the immobilized cells.Issued as National Research Council of Canada Publication Number 19475. 相似文献
5.
Summary The fermentation of D-xylose byPachysolen tannophilus Y2460,Pichia stipitis Y7124,Kluyveromyces marxianus Y2415 andCandida shehatae Y12878 was investigated in aerobic, anaerobic and microaerophilic batch cultures. The aeration rate greatly influenced the fermentations; growth, rate of ethanol production and oxidation of ethanol are affected. Of the strains tested,Pichia stipitis appears superior; under anaerobic conditions it converts D-xylose (20 g/l) to ethanol with a yield of 0.40 g/l and it exhibits the highest ethanol specific productivity (3.5 g of ethanol per g dry cell per day) under microaerophilic conditions. 相似文献
6.
Summary An inoculum of initially freely suspended cell aggregates ofCapsicum frutescens was immobilised in porous polyurethane foam matrices. Subsequent growth and substrate consumption of these immobilised cells in batch culture were measured and compared with those of suspension cultures. The results showed that the maximum specific growth rate of freely suspended cells was slightly higher than that of immobilised cells but the overall growth patterns and final cell yields were similar. 相似文献
7.
Summary The effects of the aeration rate, the pH value, the temperature of the culture medium and of the age of cells on the excretion of metabolites by mutant strains of Alcaligenes eutrophus were studied. With lactate or gluconate as substrates, ethanol, 3-hydroxybutanoate, succinate, cis-aconitate, 2-oxo-3-methylbutanoate and 2-oxoglutarate were excreted, each at a distinct low aeration rate. Maximum concentrations of metabolites were found at pH 7.0 at 30°C when ammonia was growth limiting and the carbon substrate was present in excess. Excretion occurred only by viable intact cells. 相似文献
8.
Summary A study of the influence of temperature, aeration rate, and substrate water content on sporulation of Penicillium roqueforti on buckwheat seeds in a fixed bed reactor is described. Use of an experimental procedure based on a 23 factorial design allowed optimum to be determined as 23.5° C for temperature, 0.48 g/g dry matter for substrate water content and 4.42 VVH for aeration rate. 相似文献
9.
Summary The effects of the non-ionic surfactant, Pluronic F-68, on growth and structure ofSolanum dulcamara cells in suspension culture have been studied. Growth of cells, as measured by dry weight, was unaffected by low concentrations (0.01–1.0% w/v) of pluronic, while culture with higher concentrations (2.5–10.0%) resulted in cell death. It is suggested that low concentrations of pluronic may be valuable supplements in plant cell cultures to protect against mechanical damage and to manipulate membrane systems. 相似文献
10.
HEGARTY P. K.; SMART N. J.; SCRAGG A. H.; FOWLER M. W. 《Journal of experimental botany》1986,37(12):1911-1920
An investigation was carried out to examine the effect of aerationon the growth of Catharanthus roseus suspension cultures inairlift bioreactors. A high aeration rate (0·86 v.v.m.)was found to inhibit the growth of cultures. Venting culturesat a high rate with low oxygen content gas mixtures was equallyinhibitory to culture growth, showing that high aeration wasnot inhibitory as a result of oxygen toxicity. The dissolvedcarbon dioxide tension was found to be lower in cultures operatedat high aeration than those operated at low aeration. Supplyingexogenous CO2 to cultures at high aeration restored the CO2tension to values normally encountered at a low aeration rate,and was found to alleviate the inhibitory effects at high aeration.However, further increasing the CO2 supply to cultures was foundto be severely inhibitory to growth. Therefore, the growth ofC. roseus cultures is very sensitive to dissolved CO2 concentration,growth being inhibited at values either higher or lower thanan optimum. Key words: Aeration, carbon dioxide, Catharanthus roseus suspension culture 相似文献
11.
Y Kaziro 《Biochemical and biophysical research communications》1976,68(2):430-435
In an exponentially growing culture of E. coli, the concentration of cyclic guanosine 3′:5′-monophosphate (cyclic GMP) was found to increase in parallel with the bacterial growth. As the cells approach the stationary phase of growth, the increment of cyclic GMP also ceases progressively to reach to a plateau. When cells are separated from the medium by centrifugation, almost all of the cyclic GMP is recovered in the culture supernatant. The amount of cyclic GMP accumulated is proportional to the number of cells present in the culture. These results suggest that a constant number of cyclic GMP molecules is synthesized each generation of E. coli, and is excreted from the cells to accumulate into the medium. 相似文献
12.
Gregory W. Luli Steven M. Schlasner Donald E. Ordaz Marc Mason William R. Strohl 《Biotechnology Techniques》1987,1(4):225-230
Summary A computer-assisted on-line glucose analyzer was developed for feed-back control of cell growth. Using this system the glucose consumption rate for Escherichia coli was determined to be linear during batch culture at 0.37 g/hr. On-line feed-back control of glucose concentration at 1.5±0.5 g/L was used with fed-batch cultures to produce 31.2 g dry weight of E. coli cells/L in 12 h. 相似文献
13.
Summary The influence of the reciprocating movement of a silicon membrane tubing aeration system on the metabolic performance of Spodoptera frugiperda cells was investigated in a stirred reactor. 相似文献
14.
Summary The effects of mode of growth on citric acid production by A. niger were studied using surface culture, shake culture and the disc fermenter. The disc fermenter enabled the effects of medium exchange with biomass retention to be examined. 相似文献
15.
R. T. Tyler U. Eilert C. O. M. Rijnders I. A. Roewer W. G. W. Kurz 《Plant cell reports》1988,7(6):410-413
Papaver somniferum L. (opium poppy) cells were elicited with a Botrytis sp. homogenate and cultured by a semi-continuous process. Elicitation induced synthesis of sanguinarine and dihydrosanguinarine. Significant release of both alkaloids into the culture medium occurred. Medium exchange at 2-day intervals enabled product recovery from spent medium and maintained culture viability. Culture growth was not inhibited by elicitor treatment necessitating sub-culture prior to re-elicitation. Re-elicited cultures displayed an increasing sensitivity (reduced growth rate, higher alkaloid yield) to the elicitor with each successive treatment and did not survive a fourth elicitation.Abbreviations DW
dry weight
- FW
fresh weight
- 2,4-D
2,4-dichlorophenoxyacetic acid
- SGE
sanguinarine
- DSGE
dihydrosanguinarine
Publication 29143 from the National Research Council of Canada 相似文献
16.
Summary The stability of the plasmid pJDB 248 has been measured in theS. cerevisiae strain S150-2B growing in a chemostat under conditions of glucose limitation. It was found that reducing the growth rate of the culture led to a more rapid loss of the plasmid from the cells. 相似文献
17.
Hyun Sang Lee Shin Hye Park Jong Ho Lee Hong Kum Lee 《Biotechnology and Bioprocess Engineering》2001,6(5):359-362
The production of an extracellular polysaccharide, EPS-R, from the marine bacteriumHahella chejuensis was investigated at various aeration rates in a batch culture. Higher aeration rate resulted in enhanced EPS production and
increased the viscosity of the culture broth. At an aeration rate of 1.5 vvm, EPS-R (12.2 g/L) was obtained with a yield (Y
P/S) of 0.6 from the STN medium after 72h of cultivation. TheH. chejuensis cells changed their rod morphology to a short-rod form in the stationary growth phase. 相似文献
18.
Summary A culture technique, based on the growth of a microorganism on inert porous particles (e. g. pozzolano) impregnated and continuously fed with substrate is applied to the growth and spore production ofPenicillium roqueforti. The composition and the feed rate of the medium can be controlled, and the biomass is directly estimated.P. roqueforti exhibits a diauxic growth on the medium containing sucrose and malt extract used, and 1.5 109 spores/g pozzolano may be obtained. 相似文献
19.
Glucose-limited bean cells (Phaseolus vulgaris L.) were grown in a modified bacterial fermentor at a constant pH of 4.8. The cultures were kept in steady state at different specific growth rates varying from 0.00216 h–1 to 0.0106 h–1. Culture conditions are described that are needed to start a continuous culture. First, it was essential to use log-phase cells as starting material. Second, it was important to increase the dilution rate gradually, otherwise cells in the culture aggregated. Cells grown at the highest dilution rate employed contained twice as much protein per gram dry weight as cells grown at the lowest dilution rate. The composition of the cell walls also varied with the dilution rate in contrast to their relatively constant composition when grown in batch culture. 相似文献
20.
Correlation between gramidicin C biosynthesis and sporulation in the process of Bac. brevis var. G.B. cultivation under various aeration conditions was studied. It was shown that biosynthesis of gramicidin C was characteristic of the young cells and its level was the highest during the culture active growth. The time of the sporulating forms appearance depended on the aeration rate which defined the quantitative composition of the population during the phase of the culture active growth and the stationary phase. Under the optimal aeration conditions the spore formation started during the phase of the culture active growth after some decrease in the maximum level of the cell productivity with respect to the antibiotic. When the aeration rate was increased the spore formation was shifted to later periods of the culture development, i.e. the stationary phase and the phase of the cell autolysis, the gap between the highest levels of gramicidin C buosynthesis and the beginning of sporulation being increased. Under certain aeration conditions the spore formation was not observed, while gramicidin C was synthesized. A conclusion has been made that there is no correlation between gramacidine C biosynthesis and sporualtion in Bacillus brevis var. G.B. 相似文献