Chemically Defined Medium for the Growth of Clostridium perfringens

A defined medium which supports growth of Clostridium perfringens at low inoculum levels was developed. Generation time for strain 8797 was 1.5 times greater than previously reported for growth in purged fluid thioglycolate medium.     

Chemically Defined Medium for Growth and Sporulation of Clostridium perfringens

A chemically defined medium was developed that could support sporulation and growth of Clostridium perfringens strains ATCC 12916 and H9. This medium consisted of a modification of the basal medium of Boyd et al. plus 0.1% sodium thioglycolate and 0.5% monosodium glutamate. Five other strains grew, but did not sporulate, in this medium. With the addition of more vatamins into the medium, two more strains grew but did not sporulate. The effects of glucose, monosodium glutamate, ammonium glutamate, and sodium thioglycolate on growth and sporulation of C. perfringens ATCC 12916 in the defined medium was investigated.     

Heat-stable Chemically Defined Medium for Growth of Animal Cells in Suspension

Procedures are described for preparation of a chemically defined medium, capable of being autoclaved, for the cultivation of animal cells in suspension. Yields of 34.1 x 10(5), 33.8 x 10(5), and 47.1 x 10(5) cells per ml were recorded for cat kidney, HeLa, and mouse fibroblast (L) cells after 6, 10, and 10 days of incubation, respectively.     

Chemically Defined Medium for Growth of Clostridium thermocellum, a Cellulolytic Thermophilic Anaerobe

Nutritional requirements of Clostridium thermocellum were examined, and a defined medium was formulated which supported reproducible growth through 10 serial subcultures.     

Factors Influencing the Growth of Glaucoma chattoni in a Chemically Defined Medium*

SYNOPSIS. Glaucoma chattoni strain A has been grown in the chemically defined medium previously used for Colpidium campylum and Tetrahymena pyriformis. It was necessary to modify the amino acid, nucleotide and other components of the medium in order to obtain optimum growth. The modified medium contained 17 amino acids, nucleic acid components, fatty acids, stigmasterol, sodium acetate, a mixture of B-vitamins and several inorganic salts.     

Chemically Defined Minimal Medium for Growth of the Anaerobic Cellulolytic Thermophile Clostridium thermocellum

A minimal chemically defined medium has been developed for Clostridium thermocellum. The growth factors required are biotin, pyridoxamine, vitamin B₁₂, and p-aminobenzoic acid.     

Vero细胞微载体培养的化学成分明确无血清培养基的设计

目的：设计适用于Vero细胞微载体培养的化学成分明确无血清培养基。方法：以商品化的DMEM／F12合成培养基为基础培养基,应用Plackett—Burman实验设计和响应面分析法设计支持Vero细胞微载体培养的化学成分明确无血清培养基。结果：以细胞密度为评价指标,在单因素实验的基础上采用Plackett-Burman实验设计考察10种培养基添加成分对Vero细胞生长的影响,确定了3种对Vero细胞生长起明显促进作用的培养基添加成分,为胰岛素、血清素和腐胺。继而利用响应面法分析了这3种添加成分的最佳水平范围,设计了一种支持Vero细胞贴附培养的无血清培养基（VERO—SFM—A）。在Bellco搅拌式培养瓶中采用VERO-SFM．A和Cytodex1微载体培养Vero细胞,细胞密度由接种时的4×10^5cells／ml增加到培养6d后的22．3×10^cells／ml,细胞活力保持在96％以上。结论：VERO—SFM—A能够有效地支持Vero细胞在微载体表面固定化生长并达到较高的细胞密度,具有实际应用于Vero细胞微载体规模化培养的应用潜力。     

Insights into Actinobacillus succinogenes Fermentative Metabolism in a Chemically Defined Growth Medium

Chemically defined media allow for a variety of metabolic studies that are not possible with undefined media. A defined medium, AM3, was created to expand the experimental opportunities for investigating the fermentative metabolism of succinate-producing Actinobacillus succinogenes. AM3 is a phosphate-buffered medium containing vitamins, minerals, NH₄Cl as the main nitrogen source, and glutamate, cysteine, and methionine as required amino acids. A. succinogenes growth trends and end product distributions in AM3 and rich medium fermentations were compared. The effects of NaHCO₃ concentration in AM3 on end product distribution, growth rate, and metabolic rates were also examined. The A. succinogenes growth rate was 1.3 to 1.4 times higher at an NaHCO₃ concentration of 25 mM than at any other NaHCO₃ concentration, likely because both energy-producing metabolic branches (i.e., the succinate-producing branch and the formate-, acetate-, and ethanol-producing branch) were functioning at relatively high rates in the presence of 25 mM bicarbonate. To improve the accuracy of the A. succinogenes metabolic map, the reasons for A. succinogenes glutamate auxotrophy were examined by enzyme assays and by testing the ability of glutamate precursors to support growth. Enzyme activities were detected for glutamate synthesis that required glutamine or α-ketoglutarate. The inability to synthesize α-ketoglutarate from glucose indicates that at least two tricarboxylic acid cycle-associated enzyme activities are absent in A. succinogenes.     

High Aflatoxin Production on a Chemically Defined Medium

Aspergillus parasiticus ATCC 15517 produced 28 to 30 mg of aflatoxin per 100 ml of a medium containing sucrose, asparagine, and salts in stationary and shaken cultures. In the absence of asparagine in the medium, the toxin yields fell drastically, and the thin-layer chromatograms of the chloroform extracts of the cultures indicated the total absence of aflatoxin G₁ and the presence of new intense blue and green fluorescent bands having R_F values lower than aflatoxins. Initial pH was critical and had to be around 4.5 for good growth and high toxin production on this medium. Optimum concentrations of KH₂PO₄ and MgSO₄·7H₂O in the medium were much lower than those normally used in fungal growth media.     

Development of a Defined Minimal Medium for the Growth of Edwardsiella ictaluri

In this report, a complete defined medium and a minimally defined medium are described for Edwardsiella ictaluri. The complete defined medium consists of 46 individual components, including a basal salt solution, glucose, magnesium sulfate, iron sulfate, six trace metals, four nucleotides, 10 vitamins, and 19 amino acids. This medium supports growth in broth and on solid media. Optimal growth at 30(deg)C was obtained at pH 7.0, and at an osmolality of 390 mosmol/kg of H(inf2)O, with a glucose concentration of 4 g/liter. The defined minimal medium reduces the 46 components of the complete medium to eight essential components, including the basal salt solution, glucose, magnesium sulfate, pantothenic acid, and niacinamide. In addition, specific amino acids that depend on the specific requirements of the individual strains of E. ictaluri are added.     

A Chemically Defined Medium for Rabbit Embryo Cryopreservation

This study evaluates a new synthetic substitute (CRYO3, Ref. 5617, Stem Alpha, France) for animal-based products in rabbit embryo cryopreservation solutions. This evaluation was performed using two approaches: a thermodynamic approach using differential scanning calorimetry and a biological approach using rabbit embryo slow-freezing. During the experiment, foetal calf serum (FCS) was used as a reference. Because FCS varies widely by supplier, three different FCS were selected for the thermodynamic approach. The rabbit embryo slow-freezing solutions were made from Dulbecco''s phosphate buffer saline containing 1.5 M Dimethyl Sulfoxide and 18% (v.v⁻¹) of CRYO3 or 18% (v.v⁻¹) of FCS. These solutions were evaluated using four characteristics: the end of melting temperature, the enthalpy of crystallisation (thermodynamic approach) and the embryo survival rates after culture and embryo transfer (biological approach). In the thermodynamic approach, the solutions containing one of the three different FCS had similar mean thermodynamic characteristics but had different variabilities in the overall data with aberrant values. The solution containing CRYO3 had similar thermodynamic properties when compared to those containing FCS. Moreover, no aberrant value was measured in the solution containing CRYO3. This solution appears to be more stable than the solutions containing a FCS. In the biological approach, the in vitro embryo survival rates obtained with the solution containing CRYO3 (73.7% and 81.3%) and with the solution containing a FCS (77.6% and 71.9%) were similar (p = 0.7). Nevertheless, during the in vivo evaluation, the implantation rate (21.8%) and the live-foetuses rate (18.8%) of the CRYO3 group were significantly higher than the implantation rate (7.1%, p = 0.0002) and the live-foetuses rate (5.3%, p = 0.0002) of the FCS group. The pregnancy rate was also higher in the CRYO3 group compared to the FCS group (81.3% and 43.8%, respectively, p = 0.066). We conclude that CRYO3 can be used as a chemically defined substitute for animal-based products in rabbit embryo cryopreservation solutions.     

Development of a Defined Medium for Growth of Cercospora rosicola Passerini

A simple synthetic liquid medium containing a single amino acid, glucose, salts, trace metals, and thiamine was developed for cultivation of Cercospora rosicola Passerini. Thiamine was shown to be important to growth. Culture of C. rosicola Passerini in a chemically defined medium makes possible studies of (+)-abscisic acid biosynthesis and regulation.     

Nutritional Studies on Acanthamoeba culbertsoni and Development of Chemically Defined Medium

A chemically defined medium containing 11 amino acids, 3 vitamins, 6 inorganic salts and glucose, yielding maximum cell densities of 1.5-2.5 × 10⁷ cells/ml, has been developed for Acanthamoeba culbertsoni with a mean generation time (MGT) of 10 h. A medium containing six amino acids viz. arginine, methionine, leucine, isoleucine, valine and glycine along with other components could also support good albeit slower growth (MGT 27 h) of the amoeba. Acetate did not serve as a suitable carbon/energy source for A. culbertsoni. This organism bears close resemblance in its nutritional requirements to other Acanthamoeba especially A. polyphaga.     

Microcycle Sporogenesis of Bacillus cereus in a Chemically Defined Medium

A chemically defined medium which allowed germination, outgrowth, and subsequent resporulation of Bacillus cereus T spores, without intervening cell division (microcycle sporogenesis), is described. No medium replacement was required. The second-stage spores were heat-stable and had similar germination characteristics and dipicolinic acid content to primary spores. Deoxyribonucleic acid (DNA) replication began soon after germination and there was a doubling in the DNA content of the cells within 2 hr.     

Lovastatin Biosynthesis by Aspergillus terreus in a Chemically Defined Medium

Lovastatin is a secondary metabolite produced by Aspergillus terreus. A chemically defined medium was developed in order to investigate the influence of carbon and nitrogen sources on lovastatin biosynthesis. Among several organic and inorganic defined nitrogen sources metabolized by A. terreus, glutamate and histidine gave the highest lovastatin biosynthesis level. For cultures on glucose and glutamate, lovastatin synthesis initiated when glucose consumption levelled off. When A. terreus was grown on lactose, lovastatin production initiated in the presence of residual lactose. Experimental results showed that carbon source starvation is required in addition to relief of glucose repression, while glutamate did not repress biosynthesis. A threefold-higher specific productivity was found with the defined medium on glucose and glutamate, compared to growth on complex medium with glucose, peptonized milk, and yeast extract.     

Production of Hemolysin by Vibrio parahaemolyticus in a Chemically Defined Medium

A chemically defined medium capable of supporting the production of heat-stable and heat-labile hemolysins by Vibrio parahaemolyticus is described. The indispensability of serine and glutamic acid for hemolysin production is also demonstrated.     

Evaluation of Live Tularemia Vaccine Prepared in a Chemically Defined Medium

A chemically defined medium was prepared which adequately supported growth of a vaccine strain of Pasteurella tularensis. This medium differed from those previously described in: (i) concentration of components, (ii) a requirement for calcium pantothenate to obtain increased growth, and (iii) a low initial pH. Varying the concentration of individual components up to 10 times the standard amount did not increase the viable population or affect dissociation. The vaccine strain grown in this chemically defined medium, although lower in viable population, appears to retain its identity and to be equal in potency to that prepared by the conventional method. This preliminary study indicates the potential utility of this medium as a basis for controlled studies of a live bacterial vaccine in terms of growth characteristics, dissociation, virulence, and immunogenicity.