scholarly journals Factors Affecting Exocellular Polysaccharide Production by Lactobacillus delbrueckii subsp.bulgaricus Grown in a Chemically Defined Medium

2000 ◽  
Vol 66 (8) ◽  
pp. 3427-3431 ◽  
Author(s):  
Sandrine Petry ◽  
Sylviane Furlan ◽  
Marie-Jeanne Crepeau ◽  
Jutta Cerning ◽  
Michel Desmazeaud
Keyword(s):  
Carbon Source ◽  
Defined Medium ◽  
Lactobacillus Delbrueckii ◽  
Composition Analysis ◽  
Chemically Defined Medium ◽  
Fermentation Conditions ◽  
Factors Affecting ◽  
Exocellular Polysaccharide ◽  
The Individual ◽  
Ph Controlled

ABSTRACT We developed a chemically defined medium (CDM) containing lactose or glucose as the carbon source that supports growth and exopolysaccharide (EPS) production of two strains ofLactobacillus delbrueckii subsp. bulgaricus. The factors found to affect EPS production in this medium were oxygen, pH, temperature, and medium constituents, such as orotic acid and the carbon source. EPS production was greatest during the stationary phase. Composition analysis of EPS isolated at different growth phases and produced under different fermentation conditions (varying carbon source or pH) revealed that the component sugars were the same. The EPS from strain L. delbrueckii subsp.bulgaricus CNRZ 1187 contained galactose and glucose, and that of strain L. delbrueckii subsp. bulgaricusCNRZ 416 contained galactose, glucose, and rhamnose. However, the relative proportions of the individual monosaccharides differed, suggesting that repeating unit structures can vary according to specific medium alterations. Under pH-controlled fermentation conditions, L. delbrueckii subsp. bulgaricusstrains produced as much EPS in the CDM as in milk. Furthermore, the relative proportions of individual monosaccharides of EPS produced in pH-controlled CDM or in milk were very similar. The CDM we developed may be a useful model and an alternative to milk in studies of EPS production.

scholarly journals Physiological Study of Lactobacillus delbrueckii subsp. bulgaricus Strains in a Novel Chemically Defined Medium

2000 ◽  
Vol 66 (12) ◽  
pp. 5306-5311 ◽  
Author(s):  
Christian Chervaux ◽  
S. Dusko Ehrlich ◽  
Emmanuelle Maguin
Keyword(s):  
Carbon Sources ◽  
Streptococcus Thermophilus ◽  
Defined Medium ◽  
Lactobacillus Delbrueckii ◽  
Protein Labeling ◽  
Chemically Defined Medium ◽  
Phosphotransferase System ◽  
Nutritional Conditions ◽  
Labeling Method

ABSTRACT We developed a chemically defined medium called milieu proche du lait (MPL), in which 22 Lactobacillus delbrueckii subsp.bulgaricus (L. bulgaricus) strains exhibited growth rates ranging from 0.55 to 1 h−1. MPL can also be used for cultivation of other lactobacilli and Streptococcus thermophilus. The growth characteristics of L. bulgaricus in MPL containing different carbon sources were determined, including an initial characterization of the phosphotransferase system transporters involved. For the 22 tested strains, growth on lactose was faster than on glucose, mannose, and fructose. Lactose concentrations below 0.4% were limiting for growth. We isolated 2-deoxyglucose-resistant mutants from strains CNRZ397 and ATCC 11842. CNRZ397-derived mutants were all deficient for glucose, fructose, and mannose utilization, indicating that these three sugars are probably transported via a unique mannose-specific-enzyme-II-like transporter. In contrast, mutants of ATCC 11842 exhibited diverse phenotypes, suggesting that multiple transporters may exist in that strain. We also developed a protein labeling method and verified that exopolysaccharide production and phage infection can occur in MPL. The MPL medium should thus be useful in conducting physiological studies ofL. bulgaricus and other lactic acid bacteria under well controlled nutritional conditions.

scholarly journals Lovastatin Biosynthesis by Aspergillus terreus in a Chemically Defined Medium

2001 ◽  
Vol 67 (6) ◽  
pp. 2596-2602 ◽  
Author(s):  
Hassan Hajjaj ◽  
Peter Niederberger ◽  
Philippe Duboc
Keyword(s):  
Carbon Source ◽  
Aspergillus Terreus ◽  
Glucose Repression ◽  
Nitrogen Sources ◽  
Glucose Consumption ◽  
Defined Medium ◽  
Specific Productivity ◽  
Chemically Defined Medium ◽  
Carbon And Nitrogen Sources ◽  
Carbon And Nitrogen

ABSTRACT 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.

Na+ responses of two marine bacteria that did not appear to require Na+ for growth

1993 ◽  
Vol 39 (3) ◽  
pp. 297-303 ◽  
Author(s):  
Michelle F. Manuel ◽  
Gesine A. Wisse ◽  
Robert A. MacLeod
Keyword(s):  
Carbon Source ◽  
Liquid Medium ◽  
Marine Bacteria ◽  
Binding Sites ◽  
Initial Rate ◽  
Nadh Oxidase ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Limited Extent ◽  
Bacterial Strains

Two Gram-negative heterotrophic marine bacterial strains had been reported not to require Na+ when grown on a chemically defined medium solidifed with purified agar and prepared without added Na+. When these strains were tested in a chemically defined liquid medium they required at least 3 mM Na + for growth. The agar used in the plating medium was found to contribute 3.3 mM Na+. Increasing the concentrations of Na+ in the liquid medium above 3 mM increased the rate and extent of growth of both organisms and decreased the lag periods. Optimal Na+ concentrations for growth varied from 100 to 500 mM depending on the organism and the carbon source in the medium. Na+ was also required for the transport of the carbon source into the cells. For the maximal rate of transport of L-glutamate, one organism required only 10 mM Na +, the other, 50 mM. For acetate and succinate transport the optimal Na+ concentrations varied from 30 to 200 mM depending on the substrate and the organism. When the initial rate of transport of glutamate into one of the organisms was plotted against Na+ concentration the reponse curve was sigmoid and a Hill plot of the data indicated that the transport protein may possess three binding sites for Na+. Evidence was obtained indicating that both organisms possess a Na+-stimulated NADH oxidase. The results indicate that there are marine bacteria that grow to a limited extent at appreciably lower concentrations of Na+ than have been realized previously and for these a much more definitive examination of the requirement for Na+ is necessary.Key words: marine bacteria, Na+ requirement, growth, membrane transport, NADH oxidase.

Factors affecting the production of m-cresol by Valsa friesii

1970 ◽  
Vol 16 (7) ◽  
pp. 587-593
Author(s):  
J. J. Child ◽  
R. H. Haskins
Keyword(s):  
Culture Filtrate ◽  
Colorimetric Assay ◽  
Defined Medium ◽  
Distilled Water ◽  
Shake Culture ◽  
Chemically Defined Medium ◽  
Factors Affecting ◽  
High Yields

A chemically defined medium for the cultivation of Valsa friesii Duby (Fuckel) PRL 1736 has been developed and conditions established for accumulation of high yields of m-cresol in the culture filtrate. Yields of 1 g per liter as determined by colorimetric assay using 4-aminoantipyrine are obtained after 10 days' incubation in shake culture at 28 °C in the absence of light on a medium containing glucose, 15 g; alanine, 2 g; K2HPO4, 0.3 g; KH2PO4, 0.2 g; salts (0.2 g MgSO4∙7H2O, 0.1 g NaCl, 0.1 g CaCl2, 0.015 g FeSO4, and 0.25 mg ZnCl2); and vitamins (4 mg each of thiamine HCl, pyridoxin HCl, 10 mg inositol, and 10 μg biotin) per liter of distilled water. The organism is shown to tolerate higher concentrations of m-cresol than do eight other fungi tested.

scholarly journals Enhancement of Exopolysaccharide Production byLactobacillus delbrueckii subsp. bulgaricus NCFB 2772 with a Simplified Defined Medium

1998 ◽  
Vol 64 (4) ◽  
pp. 1333-1337 ◽  
Author(s):  
G. J. Grobben ◽  
I. Chin-Joe ◽  
V. A. Kitzen ◽  
I. C. Boels ◽  
F. Boer ◽  
...  
Keyword(s):  
Amino Acids ◽  
Defined Medium ◽  
Complete Loss ◽  
Lactobacillus Delbrueckii ◽  
Complete Medium ◽  
Calcium Pantothenate ◽  
Chemically Defined Medium ◽  
Batch Cultures ◽  
Exopolysaccharide Production ◽  
Medium Components

ABSTRACT The aim of this work was to investigate the medium requirements for growth and production of exopolysaccharides by Lactobacillus delbrueckii subsp. bulgaricus NCFB 2772. The strain was grown in batch cultures on a chemically defined medium, and the technique of single omission of medium components was applied to determine the nutritional requirements. The omission of aspartic acid, glutamic acid, or glycine affected growth only slightly, and the omission of glutamine, asparagine, or threonine resulted in a stronger reduction of the growth. All the other amino acids were essential. Multiple omissions of amino acids caused an almost complete loss of growth. L. delbrueckii subsp. bulgaricusrequired only riboflavin, calcium pantothenate, and nicotinic acid as individual vitamins. Surprisingly, when only these vitamins were present in the medium and other vitamins were not, less growth was observed than in the complete medium but the amount of exopolysaccharide produced was significantly greater. These observations were studied in more detail with a simplified defined medium in which L. delbrueckii subsp.bulgaricus was able to grow and produce exopolysaccharides. Although the final optical density in the simplified medium was lower, the production of exopolysaccharides was about twofold higher than in the complete medium.

Additional effect of epidermal growth factor during in vitro maturation for individual bovine oocytes using a chemically defined medium

Zygote ◽  
2004 ◽  
Vol 12 (2) ◽  
pp. 143-150 ◽  
Author(s):  
Takahiro Oyamada ◽  
Hiroshi Iwayama ◽  
Yutaka Fukui
Keyword(s):  
Growth Factor ◽  
Epidermal Growth Factor ◽  
Defined Medium ◽  
Control Medium ◽  
Chemically Defined Medium ◽  
Blastocyst Formation ◽  
Epidermal Growth ◽  
The Individual ◽  
Bovine Oocytes

This study was performed to establish an individual bovine oocyte-IVP system using a chemically defined simple medium (mSOFaa containing 1 mg/ml polyvinyl alcohol: PVA) and to investigate the effects of epidermal growth factor (EGF) during oocyte maturation on in vitro maturation, fertilization and embryonic development. Cumulus–oocyte complexes were collected from bovine ovaries and were matured in mSOFaa containing PVA (control medium) supplemented with 0, 1, 10 or 50 ng/ml of EGF. Two further groups (TCM199 and mSOFaa, supplemented with 10% fetal calf serum were also included. In this study, mSOFaa containing PVA were used as a basic medium for fertilization and embryo development in vitro. Experiments were conducted in both group- and individual-IVP systems. In the group-IVP system, the proportion of matured oocytes (MII) in the control medium (62.7%±5.0%) was significantly (p<0.05) lower than in all other treatments, and in the individual-IVP system, the addition of 1 ng/ml EGF significantly (p<0.05) increased the maturation rate (1 ng/ml EGF vs control: 76.2%±5.4% vs 57.1%±14.4%). The addition of EGF did not affect the proportions of penetrated and normally fertilized oocytes in either individual- or group-culture systems. In the group-IVP system, no significant difference among treatments was found in the rate of blastocyst formation, whereas in the individual-IVP system the control medium supplemented with 10 ng/ml EGF resulted in a significantly (p<0.05) higher the rate of blastocyst formation (20.0±5.2%) than that in the control medium (6.2%±3.5%). These results indicate that bovine oocytes can successfully develop to blastocysts in an individual-IVP system using a single chemically defined medium, and that the group-IVP system also resulted in a similar level of blastocyst formation to that in a standard multiple-media system in our laboratory. The effect of EGF during oocyte maturation medium differed depending on whether embryos were cultured individually or in groups.

THE METABOLISM OF YEAST SPORULATION: I. EFFECT OF CERTAIN METABOLITES AND INHIBITORS

1956 ◽  
Vol 2 (6) ◽  
pp. 519-537 ◽  
Author(s):  
J. J. Miller ◽  
Clara Halpern
Keyword(s):  
Carbon Source ◽  
Ethylene Glycol ◽  
Marked Effect ◽  
Defined Medium ◽  
Yeast Nitrogen Base ◽  
Chemically Defined Medium ◽  
Optimum Growth ◽  
Nitrogen Base ◽  
Acetate Concentration ◽  
Growth Experiments

Cells of bakers' yeast harvested from a chemically-defined medium were placed in buffer for sporulation experiments and in Wickerham's yeast nitrogen base for growth experiments. The metabolites were included in these two solutions in concentrations up to 1% usually, and growth and sporulation were compared under conditions as nearly equivalent as possible. Optimum sporulation was observed in 0.033–0.1% glucose, 1% pyruvate, 0.033% ethanol, 0.033% acetaldehyde, and 0.33% acetate. Optimum growth in one day occurred in 1% glucose, 1% pyruvate, 0.1–0.33% ethanol, 0.0033% acetaldehyde, and 0.033% acetate. Very few asci were found in 0.33% glucose or in 1% ethanol, but cells transferred to buffer after one day in such solutions sporulated well. The addition of 0.33% glucose or 1% ethanol to 0.3% acetate suppressed sporulation. In 0.1% acetaldehyde no sporulation or growth was evident, with or without the addition of 0.3% acetate. Acetoin, 2,3-butylene glycol, and ethylene glycol had no marked effect on sporulation and growth. Sporulation and growth were inhibited by 7 × 10−4M fluoroacetate with 0.3% acetate or 0.3% ethanol as the carbon source. Inhibition was much greater when the acetate concentration was decreased to 0.03%. Sporulation in glucose was inhibited by fluoroacetate, while growth in glucose was little affected. With acetate as the carbon source, sporulation was more sensitive than growth to urethane, while the reverse was found with azide, malachite green, cyanide, and dinitrophenol. The two processes seemed about equally sensitive to arsenite, p-nitrophenol, and malonic acid. Most of the asci that formed in glucose solutions were two-spored. In acetate, ethanol, and pyruvate three- and four-spored asci usually predominated, except in the weaker concentrations.

Nutritional factors affecting the synthesis of an antiphagocytic factor by group E streptococci

1984 ◽  
Vol 30 (3) ◽  
pp. 406-411 ◽  
Author(s):  
G. E. Wessman
Keyword(s):  
Molecular Weight ◽  
Defined Medium ◽  
Chemically Defined Medium ◽  
Nutritional Factors ◽  
Factors Affecting ◽  
Cultural Medium ◽  
Molecular Weight Cutoff ◽  
Tryptose Phosphate Broth ◽  
Nominal Molecular Weight ◽  
Cells Cultured

Effects of components of the cultural medium on formation of a group E streptococcal antiphagocytic factor (APF), as detected by an indirect bactericidal test, were studied. Bovine serum albumin (BSA) replaced serum in promoting synthesis of APF in a chemically defined medium (CDM), Todd–Hewitt broth (THB), or tryptose phosphate broth (TPB). Stimulatory factors in BSA were not retained by diafiltration membranes of nominal molecular weight cutoff limits of 10 000 or greater. Citrate, lactate, pyruvate, or oleate, often found in BSA, could not replace BSA in stimulating synthesis of APF. Cells cultured in THB were more resistant to phagocytosis by porcine leukocytes than those grown in CDM or TPB, and the addition of varying amounts of THB to CDM stimulated a measurable response in synthesis of APF. Specific substrates caused different rates of APF synthesis; in decreasing order of effectiveness were glucose or mannose, sucrose, fructose, and trehalose. Proteolytic activity, which might cause the production of phagocyte-sensitive cells by destroying APF activity during culture, was not detectable in significant amounts in subcultures of the age employed in bactericidal tests.

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