Optimisation de la croissance et de la sporulation de Conidiobolus obscurus en milieu défini

1985 ◽  
Vol 63 (1) ◽  
pp. 68-85 ◽  
Author(s):  
J. P. Latgé ◽  
J. J. Sanglier
Keyword(s):  
Amino Acids ◽  
Culture Medium ◽  
Pantothenic Acid ◽  
Defined Medium ◽  
Culture Conditions ◽  
Complete Darkness ◽  
Experimental Conditions ◽  
Nutritional Factors ◽  
Factors Influencing ◽  
Composite Designs

Physical and nutritional factors influencing the growth and sporulation of Conidiobolus obscurus (Hall et Dunn) Remaudière et Keller were studied using simple and fragmented factorial designs and centered composite designs. Culture conditions allowing maximum sporulation were a temperature of 20 °C, complete darkness, and a near neutral pH of around 6.5. Under our experimental conditions, dextrose influenced neither the growth nor the sporulation of C. obscurus. The cations stimulating the formation of azygospores were magnesium and to a lesser extent zinc and manganese. Sulphur must be added to the medium in a reduced or oxydized form. Phosphates must be present in the culture medium, but at a concentration less than 30 mM/L. Vitamins stimulating sporulation were thiamine, biotin, and folic acid while pantothenic acid favoured growth. Among the 20 amino acids tested, proline, leucine, methionine, glutamic and aspartic acids, glutamine, asparagine, histidine, phenylalanine, lysine, and arginine were the most favourable for growth and sporulation of C. obscurus. Growth and sporulation in the optimized defined medium containing 11 amino acids, four vitamins, four salts, and dextrose were comparable to the best results obtained in a nondefined medium composed of dextrose and yeast extract.

scholarly journals The Relation of the Composition of the Culture Medium to the Formation of Endospores by Aerobic Bacilli

1932 ◽  
Vol 32 (4) ◽  
pp. 535-543 ◽  
Author(s):  
H. L. A. Tarr
Keyword(s):  
Amino Acids ◽  
Culture Medium ◽  
Inorganic Salt ◽  
Synthetic Medium ◽  
Ammonium Phosphate ◽  
Spore Formation ◽  
Experimental Conditions ◽  
Nitrogenous Compounds ◽  
Low Concentrations ◽  
High Concentrations

1. Spore formation in eight typical members of the genusBacillushas been studied.2. Three of these strains, including one species ofB. anthracis, have been found to be practically asporogenous under the experimental conditions. In general the following statements hold good for the sporogenous races studied.3. Spore formation is almost, or entirely, inhibited by cultivation on media rich in amino acids, such as tryptic digests of casein or meat. Similar inhibition results following cultivation on a medium containing reasonably high concentrations of a mixture of amino acids and asparagine.4. When such media are suitably diluted with standard inorganic salt solutions the percentage of spores formed is greatly increased, and frequently at least 99 per cent. of spores are formed if the dilution is sufficiently high.5. When simple nitrogenous compounds such as amino acids are added to a dilute casein digest medium in which sporulation is almost complete, a definite decrease in the percentage of spores present is observed. Asparagine, which is probably readily assimilated, apparently completely hinders spore formation in most cases. Other amino acids do not exert so pronounced an effect, and ammonium phosphate does not appreciably inhibit the formation of spores.6. The fact that the addition of glycine suppresses growth markedly when it is added to a dilute casein digest medium, but does not appreciably hinder sporulation, suggests that the formation of spores is not due to any toxic effect of added compounds, or compounds already present in the medium.7. Sporulation is almost complete in a “synthetic” medium in which low concentrations of ammonium phosphate and sucrose represent the sources of nitrogen and carbon, respectively. However, frequent transfers in such a medium may inhibit spore formation partially or entirely in certain instances. This effect probably depends upon the enhanced ability of the culture in question to utilise sucrose as a source of carbon when cultivated constantly in its presence.8. It is concluded, from the above data, that endospore formation in aerobic bacilli bears an inverse relationship to the amount of available nutrient material present in the culture medium.I am indebted to Prof. Sir F. G. Hopkins and Miss M. Stephenson for their constant encouragement during the progress of this work. My thanks are due to Mr Pirie of this Department who kindly furnished me with several of the amino acids employed, and to Dr Miles of the Department of Pathology for his kindness in supplying me with certain of the cultures.

scholarly journals The glycosulphatase of Trichoderma viride

1968 ◽  
Vol 108 (3) ◽  
pp. 393-399 ◽  
Author(s):  
A G Lloyd ◽  
P J Large ◽  
M Davies ◽  
A H Olavesen ◽  
K S Dodgson
Keyword(s):  
Culture Medium ◽  
Enzyme System ◽  
Trichoderma Viride ◽  
Defined Medium ◽  
Potassium Sulphate ◽  
Experimental Conditions ◽  
Lag Period

The growth of the mould Trichoderma viride on a defined medium containing either potassium d-glucose 6-O-sulphate or potassium d-galactose 6-O-sulphate as sole sources of both carbon and sulphur is marked by the production of an enzyme system capable of liberating inorganic SO42− ions from either of the sulphate esters. The enzyme is not produced when the organism is grown with glucose (or galactose) and potassium sulphate or with glucose and methionine as sole sources of carbon and sulphur. Experimental conditions are described whereby inorganic SO42− ions liberated from potassium glucose 6-O-sulphate by the growing mould appear in the culture medium after a constant lag period of 21–24hr. The enzyme has been shown to be a simple glycosulphatase that is active towards the 6-O-sulphate esters of d-glucose and d-galactose but not towards potassium glucose 3-O-sulphate. The properties of the crude glycosulphatase show the enzyme to be appreciably different from analogous molluscan enzymes that can degrade monosaccharide sulphate esters.

Preliminary Experiments with a Defined Culture Medium for Larval Fasciola hepatica

1973 ◽  
Vol 47 (2) ◽  
pp. 181-189 ◽  
Author(s):  
R. S. V. Pullin
Keyword(s):  
Amino Acids ◽  
Culture Medium ◽  
Fasciola Hepatica ◽  
Dry Weight ◽  
Defined Medium ◽  
Inorganic Salts ◽  
Final Maturation ◽  
Defined Culture ◽  
Stock Solutions

A defined medium is described as a basis for in vitro culture work with larval Fasciola hepatica. This medium, termed BCM, can be quickly made up by using a system of stock solutions. BCM contains inorganic salts, glucose, amino acids, vitamins and antibiotics, but no lipid or proteins. Rediae can be dissected from infected snails for culture, but many appear to be contaminated with bacteria. Large rediae cannot survive in BCM but free immature cercariae can complete their final maturation in vitro. This final maturation, from the 30th to the 35th day after miracidial penetration of donor snails, includes tail growth and appearance of body pigmentation. Cercariae matured in vitro encyst successfully when transferred from BCM to water. Small rediae survive in BCM for 5 days, but show no growth or development measured as dry weight and total nitrogen.

Cultivation of Trypanosoma brucei sspp. in semi-defined and defined media

Parasitology ◽  
1973 ◽  
Vol 67 (3) ◽  
pp. 315-331 ◽  
Author(s):  
G. A. M. Cross ◽  
J. C. Manning
Keyword(s):  
Amino Acids ◽  
Tissue Culture ◽  
Trypanosoma Brucei ◽  
Culture Medium ◽  
Defined Medium ◽  
Tissue Culture Medium ◽  
Optimum Temperature ◽  
Acid Hydrolysate ◽  
Defined Media

Semi-defined and defined media for the growth of culture forms of Trypanosoma brucei sspp. have been developed by enrichment of tissue culture medium 199 with additional vitamins, amino acids, salts and other compounds. The semi-defined medium contains an acid hydrolysate of casein: in the empirically devised defined medium the casein requirement has been circumvented by inclusion of additional vitamins and amino acids. Both media are very hypertonic. Control of pH was found to be particularly critical for growth. The optimum temperature for growth in the semidefined medium was between 25°C and 28°C, but cells would undergo one or two division cycles at 37°C.

Vitamin production by a fungus symbiotic with orchids

1975 ◽  
Vol 53 (2) ◽  
pp. 156-163 ◽  
Author(s):  
Gaëtan Harvais ◽  
David Pekkala
Keyword(s):  
Amino Acids ◽  
Endophytic Fungi ◽  
Culture Medium ◽  
Pantothenic Acid ◽  
Chemical Methods ◽  
Active Growth ◽  
Nitrate Medium ◽  
Symbiotic Associations ◽  
Dual Cultures ◽  
Vitamin Production

The results of earlier axenic and dual cultures of Dactylorhiza purpurella and its symbiont indicated that the fungus may provide the orchid with some, if not all, of the vitamins in yeast extract. Here, the fungus was studied for such production in axenic liquid still cultures on mineral–sugar media, using bioassays and chemical methods. The latter proved too insensitive. Bioassays were considerably more sensitive and, after various modifications of the techniques, gave consistent results. They showed that about 33 parts per billion (ppb) nicotinic acid and (or) nicotinamide ('niacin'), 1.5 ppb thiamine, but no pantothenic acid, were readily secreted in the culture medium by the fungus. These were, respectively, at about 10% and 50% of their concentrations in the medium used for axenic orchid cultures. 'Niacin' production was studied further. There was no real correlation with dry weights. Production was greatest with 1% dextrose (vs. 2%), during the active growth phase, and on a medium containing ammonium and nitrate vs. nitrate alone as nitrogen source. On that medium, greatest yield was under restricted aeration, and conversely for the nitrate medium. Ten micrograms 'niacin' per gram dry mycelium was released into the filtrate, and 14 μg, i.e. 40% more, was retained in the mycelium. Ammonium seems more important in the synthesis of 'niacin' than of amino acids. These findings may be of great significance in relation to symbiotic associations in dual cultures and in nature. They indicate that orchids would derive more benefit from active endophytic fungi than upon their digestion.

scholarly journals Transcriptional Profiling of Porcine Blastocysts Produced In Vitro in a Chemically Defined Culture Medium

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1414
Author(s):  
Josep M. Cambra ◽  
Emilio A. Martinez ◽  
Heriberto Rodriguez-Martinez ◽  
Maria A. Gil ◽  
Cristina Cuello
Keyword(s):  
Culture Medium ◽  
Embryo Quality ◽  
Transcriptional Profiling ◽  
Defined Medium ◽  
Platelet Factor ◽  
Defined Media ◽  
Defined Culture ◽  
The Impact

The development of chemically defined media is a growing trend in in vitro embryo production (IVP). Recently, traditional undefined culture medium with bovine serum albumin (BSA) has been successfully replaced by a chemically defined medium using substances with embryotrophic properties such as platelet factor 4 (PF4). Although the use of this medium sustains IVP, the impact of defined media on the embryonic transcriptome has not been fully elucidated. This study analyzed the transcriptome of porcine IVP blastocysts, cultured in defined (PF4 group) and undefined media (BSA group) by microarrays. In vivo-derived blastocysts (IVV group) were used as a standard of maximum embryo quality. The results showed no differentially expressed genes (DEG) between the PF4 and BSA groups. However, a total of 2780 and 2577 DEGs were detected when comparing the PF4 or the BSA group with the IVV group, respectively. Most of these genes were common in both in vitro groups (2132) and present in some enriched pathways, such as cell cycle, lysosome and/or metabolic pathways. These results show that IVP conditions strongly affect embryo transcriptome and that the defined culture medium with PF4 is a guaranteed replacement for traditional culture with BSA.

Schistosoma mansoni: tail loss in relation to permeability changes during cercaria–schistosomulum transformation

Parasitology ◽  
1975 ◽  
Vol 71 (1) ◽  
pp. 9-18 ◽  
Author(s):  
R. E. Howells ◽  
S. E. Gerken ◽  
F. J. Pinto-Ramalho ◽  
U. Kawazoe ◽  
G. Gazzinelli ◽  
...  
Keyword(s):  
Amino Acids ◽  
Methylene Blue ◽  
Schistosoma Mansoni ◽  
Body Region ◽  
Experimental Conditions ◽  
General Body ◽  
Tail Loss ◽  
Permeability Changes ◽  
Extensive Lesion ◽  
Scanning Electron

The hind-body region of Schistosoma mansoni cercariae observed in the scanning electron microscope demonstrates various stages of contraction which may be compared with those of living larvae which are secreting the acetabular gland contents.No evidence for an extensive lesion was found in cercarial bodies which had shed their tails under experimental conditions. Experiments on the permeability of the larvae to sodium fluoride, methylene blue and amino acids demonstrated that tail loss significantly affects the permeability of the bodies although the effect is greater immediately after decaudation than at later times. Subsequent increases in permeability may be correlated with a change in the general body surface.

Study on Optimization of Fermentation Condition for Nitrilase-Producer Escherichia Coli BL21 (DE3)/pET-Nit

2011 ◽  
Vol 175-176 ◽  
pp. 192-196 ◽  
Author(s):  
Li Li Feng ◽  
Jian Fei Zhang ◽  
Hui Luo ◽  
Zheng Li ◽  
Hong Jie Zhang
Keyword(s):  
Escherichia Coli ◽  
Recombinant Strain ◽  
Culture Medium ◽  
Culture Conditions ◽  
Fermentation Condition ◽  
Hydrogen Phosphate ◽  
Strain Bl21 ◽  
Initial Ph ◽  
Potassium Hydrogen ◽  
Optimization Of Fermentation

The paper concentrated on the optimization of the recombinant strain BL21 (DE3)-PE7-Nit. The component of culture medium and the culture conditions were optimized. The optimized medium was: yeast extract 10 g/l, L-glutamate sodium 8 g/l, MgSO4.7H2O 0.7 g/l, Isopropyl-β-D-thiogalactopyranoside 0.3 mmol/L, potassium hydrogen phosphate 0.5 g / L, phosphate Potassium 0.5 g / L and the culture condition was: initial pH 7.0, inoculum 2%. The result showed that the activity of nitrilase prepared with these conditions increased by 130.37 % through optimization.

Sign in / Sign up

Export Citation Format

Share Document