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

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.

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On the origin of variants of the marine bacteriumDeleya aesta134 able to grow at low Na+concentration

Canadian Journal of Microbiology ◽

10.1139/m97-126 ◽

1997 ◽

Vol 43 (9) ◽

pp. 868-878 ◽

Cited By ~ 1

Author(s):

Robert A. MacLeod ◽

Patricia R. MacLeod ◽

Marc Berthelet

Keyword(s):

Liquid Medium ◽

Marine Bacteria ◽

Lag Time ◽

Defined Medium ◽

Adaptive Mutation ◽

Chemically Defined Medium ◽

Colony Type ◽

Lag Period ◽

The Mean ◽

Concentration Cells

Deleya aesta 134 grows optimally at 200 mM Na+in a chemically defined medium but at 10 mM Na+only after an extended lag period which was reduced if the cells that grew were reinoculated into medium of the same low Na+concentration. Cells that eventually grew at low Na+formed colonies on agar containing 17 mM Na+in the agar supernatant (the liquid released when the agar was compacted). Cells of the parent failed to form colonies at this Na+concentration when 102cells were plated. Colonies that formed on low Na+agar differed in appearance from colonies of the parent and three colony types were distinguished. When 106cells of D. aesta grown in liquid medium containing optimum Na+were spread on plates containing 17 mM Na+, a few variant colonies first appeared on day 4 and then increased in numbers over a 20-day period. In nine similar cultures the yield of colonies varied over a 3-log range. Fluctuation tests applied to the numbers arising from the similar cultures after different periods of incubation of the plates showed that the ratio of the variance to the mean was much greater than one initially and then increased with time. A total of seven different variants were isolated. These could be distinguished by the colony type formed, the length of the lag time preceding the first appearance of colonies, and the rate of colony accumulation on low (and in one case, high) Na+plates. The variants retained their distinctive characteristics when replated at low Na+after growth at optimum Na+. Differences in lag time and rate of colony accumulation were related to differences in Na+requirement of the variants and to the presence of other colonies on the plates. The variants appear to arise as the result of random mutations in the growing culture. There was no evidence of adaptive mutation.Key words: Deleya aesta, marine bacteria, variants, Na+response, colony accumulation, adaptive mutation.

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Lovastatin Biosynthesis by Aspergillus terreus in a Chemically Defined Medium

Applied and Environmental Microbiology ◽

10.1128/aem.67.6.2596-2602.2001 ◽

2001 ◽

Vol 67 (6) ◽

pp. 2596-2602 ◽

Cited By ~ 92

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.

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

Canadian Journal of Microbiology ◽

10.1139/m56-064 ◽

1956 ◽

Vol 2 (6) ◽

pp. 519-537 ◽

Cited By ~ 23

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.

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

Applied and Environmental Microbiology ◽

10.1128/aem.66.8.3427-3431.2000 ◽

2000 ◽

Vol 66 (8) ◽

pp. 3427-3431 ◽

Cited By ~ 99

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.

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Minimum nutritional requirements for growth of host-independent derivatives of Bdellovibrio bacteriovorus strain 109 Davis

Canadian Journal of Microbiology ◽

10.1139/m74-041 ◽

1974 ◽

Vol 20 (2) ◽

pp. 263-265 ◽

Cited By ~ 7

Author(s):

Edward E. Ishiguro

Keyword(s):

Escherichia Coli ◽

Growth Factors ◽

Carbon Source ◽

Defined Medium ◽

Nutritional Requirements ◽

Chemically Defined Medium ◽

Carbon Source Utilization ◽

Bdellovibrio Bacteriovorus ◽

Derivatives Of ◽

I Cells

A chemically defined medium for host-independent (H-I) derivatives of Bdellovibrio bacteriovorus strain 109 Davis has been developed. Carbon-source utilization studies indicated that H-I cells can assimilate a wider variety of compounds than host-dependent bdellovibrios. The defined medium did not support growth of freshly isolated H-I strains which required unidentified growth factors present in Escherichia coli cell-free extracts and in yeast extract.

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