Nitrogen nutrition and regulation of cephalosporin production in Streptomyces clavuligerus

1979 ◽  
Vol 25 (1) ◽  
pp. 61-67 ◽  
Author(s):  
Yair Aharonowitz ◽  
Arnold L. Demain
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Nitrogen Nutrition ◽  
Antibiotic Production ◽  
Inorganic Nitrogen ◽  
Amino Nitrogen ◽  
Nitrogen Sources ◽  
Streptomyces Clavuligerus ◽  
Defined Medium ◽  
Repressive Effect

When used as sole nitrogen source, certain amino acids (e.g., proline, asparagine) supported both growth and sporulation by Streptomyces clavuligerus streaked onto solid defined medium. Ammonium supported growth but suppressed sporulation. Amino nitrogen was best for cephalosporin production in liquid defined medium, although urea was almost as useful. A comparison of amino acids showed asparagine and glutamine to be the best nitrogen sources and arginine to be almost as good. Ammonium salts supported a somewhat lower growth rate than asparagine, but antibiotic production was very poor on these inorganic nitrogen sources. Addition of ammonium to asparagine did not affect growth rate but increased mycelial mass; cephalosporin production was reduced by about 75%. Antibiotic production was more closely associated with growth in the absence of ammonium than in its presence, indicating a strong inhibitory and (or) repressive effect of NH4+ on antibiotic production. Ammonium exerted its negative effect when added at 24 h or earlier, i.e. before antibiotic formation began.

Amino acid uptake systems in Bacteroides ruminicola

1979 ◽  
Vol 25 (10) ◽  
pp. 1161-1168 ◽  
Author(s):  
Roselynn M. W. Stevenson
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Nitrogen Sources ◽  
Amino Acid Uptake ◽  
Defined Medium ◽  
High Rate ◽  
Transport Systems ◽  
Acid Uptake ◽  
Chemical Structures ◽  
Kinetic Inhibition

Uptake of amino acids by Bacteroides ruminicola was observed in cells grown in a complete defined medium, containing ammonia as the nitrogen source. A high rate of uptake occurred only in fresh medium, as an inhibitory substance, possibly acetate, apparently accumulated during growth. All amino acids except proline were taken up and incorporated into cold trichloroacetic acid precipitable material. Different patterns of incorporation and different responses to 2,4-dinitrophenol and potassium ferricyanide indicated multiple uptake systems were involved. Kinetic inhibition patterns suggested six distinct systems were present for amino acid uptake, with specificities related to the chemical structures of the amino acids. Thus, the failure of free amino acids to act as sole nitrogen sources for growth of B. ruminicola is not due to the absence of transport systems for these compounds.

EFFECT OF AMMONIUM NITROGEN AND AMINO ACIDS ON PERITHECIAL FORMATION OF VENTURIA INAEQUALIS

1971 ◽  
Vol 51 (1) ◽  
pp. 29-33 ◽  
Author(s):  
R. G. ROSS ◽  
FRANCES D. J. BREMNER
Keyword(s):  
Amino Acids ◽  
Ammonium Carbonate ◽  
Venturia Inaequalis ◽  
Amino Nitrogen ◽  
Basal Medium ◽  
Nitrogen Sources ◽  
Ammonium Nitrogen ◽  
Racemic Mixture ◽  
Appreciable Change ◽  
The Media

Perithecia of Venturia inaequalis did not form in a basal medium to which was added ammonium sulfate, chloride, phosphate or tartrate as the sole sources of nitrogen, when the pH of the medium was allowed to fall to inhibitory levels. Perithecia formed with these ammonium salts as nitrogen sources when calcium carbonate was added to control the pH. With ammonium carbonate and oxalate there was no appreciable change in pH, and perithecia formed with these salts as nitrogen sources. Perithecia did not form in media with leucine as a nitrogen source. Formation of perithecia with other amino acids depended on the concentration of amino-nitrogen in the media. A substance toxic to perithecial formation may form in cultures containing leucine; if so, it is produced in different amounts by the two isomers and the racemic mixture of this amino acid.

Some nutritional aspects of the biology of ericaceous mycorrhizas

1985 ◽  
Vol 85 (3-4) ◽  
pp. 317-331 ◽  
Author(s):  
D. J. Read ◽  
R. Bajwa
Keyword(s):  
Amino Acids ◽  
Mycorrhizal Fungus ◽  
Amino Nitrogen ◽  
Nitrogen Sources ◽  
Acid Protease ◽  
Mycorrhizal Symbiosis ◽  
Mycorrhizal Infection ◽  
Plant Nitrogen ◽  
Low Concentrations

SynopsisSome aspects of the role of the ericoid mycorrhizal symbiosis in the ecology and physiology of ericaceous plants are described. Mycorrhizal infection leads to enhancement of plant nitrogen content and an experimental analysis of the basis of this effect is reported. In addition to improving the efficiency of ammonium absorption at low concentrations, the mycorrhizal endophyte utilises amino acids, peptides and proteins as nitrogen substrates for growth. These are the predominant nitrogen sources in organic heathland soil. It is suggested that the success of ericaceous plants in such soils may arise through the capacity of the mycorrhizal fungus to provide its host with access to this nutrient resource. A model is described in which absorption of ammonium and amino nitrogen leads to soil acidification, increased acid protease activity and improved vigour of the ericaceous plants.

scholarly journals Influence of Glutamate on Growth, Sporulation, and Spore Properties of Bacillus cereus ATCC 14579 in Defined Medium

2005 ◽  
Vol 71 (6) ◽  
pp. 3248-3254 ◽  
Author(s):  
Ynte P. de Vries ◽  
Ratna D. Atmadja ◽  
Luc M. Hornstra ◽  
Willem M. de Vos ◽  
Tjakko Abee
Keyword(s):  
Amino Acids ◽  
Bacillus Cereus ◽  
Exponential Growth ◽  
Dipicolinic Acid ◽  
Carbon Sources ◽  
Nitrogen Sources ◽  
Defined Medium ◽  
Mother Cells ◽  
Almost All ◽  
Time Frames

ABSTRACT A chemically defined medium in combination with an airlift fermentor system was used to study the growth and sporulation of Bacillus cereus ATCC 14579. The medium contained six amino acids and lactate as the main carbon sources. The amino acids were depleted during exponential growth, while lactate was metabolized mainly during stationary phase. Two concentrations of glutamate were used: high (20 mM; YLHG) and low (2.5 mM; YLLG). Under both conditions, sporulation was complete and synchronous. Sporulation started and was completed while significant amounts of carbon and nitrogen sources were still present in the medium, indicating that starvation was not the trigger for sporulation. Analysis of amino acids and NH4 + in the culture supernatant showed that most of the nitrogen assimilated by the bacteria was taken up during sporulation. The consumption of glutamate depended on the initial concentration; in YLLG, all of the glutamate was used early during exponential growth, while in YLHG, almost all of the glutamate was used during sporulation. In YLLG, but not in YLHG, NH4 + was taken up by the cells during sporulation. The total amount of nitrogen used by the bacteria in YLLG was less than that used by the bacteria in YLHG, although a significant amount of NH4 + was present in the medium throughout sporulation. Despite these differences, growth and temporal expression of key sigma factors involved in sporulation were parallel, indicating that the genetic time frames of sporulation were similar under both conditions. Nevertheless, in YLHG, dipicolinic acid production started later and the spores were released from the mother cells much later than in YLLG. Notably, spores had a higher heat resistance when obtained after growth in YLHG than when obtained after growth in YLLG, and the spores germinated more rapidly and completely in response to inosine, l-alanine, and a combination of these two germinants.

scholarly journals Effect of nitrogen sources on the nitrogenous forms and accumulation of amino acid in head cabbage

2008 ◽  
Vol 54 (No. 2) ◽  
pp. 66-71 ◽  
Author(s):  
E. Atanasova
Keyword(s):  
Amino Acids ◽  
Ammonium Nitrate ◽  
Nitrogen Nutrition ◽  
Calcium Nitrate ◽  
Total Content ◽  
Nitrogen Sources ◽  
Nitrogen Accumulation ◽  
Protein Nitrogen ◽  
Nitrogen Rates ◽  
Head Cabbage

The effect of two different nitrogen sources: ammonium nitrate and calcium nitrate, applied at increased rates, on the content of the total nitrogen, protein and non-protein nitrogen, and the content and composition of amino acids in head cabbage leaves was studied. The higher nitrogen accumulation was established at the ammonium nitrate fertilization compared to the calcium nitrate, but the application of Ca(NO<sub>3</sub>)<sub>2</sub> resulted in a higher content of nitrate nitrogen. More protein nitrogen was also observed in plants with Ca(NO<sub>3</sub>)<sub>2</sub> fertilization. The highest applied fertilizer rate of ammonium nitrate resulted in a significant reduction of the protein nitrogen compared to increased free amino acids. The total content of amino acids increased gradually with the increase of nitrogen rates in plants fertilized with NH<sub>4</sub>NO<sub>3</sub>. When Ca(NO<sub>3</sub>)<sub>2</sub> was applied, nitrogen rates higher than 500 mg/kg soil suppressed the synthesis of amino acids. A greater increase was observed as regards the levels of arginine, proline and some essential amino acids as lysine, phenylalanine and histidine. The increase of proline and alanine could serve as an indicator for unbalanced nitrogen nutrition.

Glucose, alpha-amino nitrogen, and amino acid exchange across the hindlimb in young double-muscled type bulls maintained at two growth rates

1996 ◽  
Vol 76 (2) ◽  
pp. 193-202 ◽  
Author(s):  
J. L. Hornick ◽  
C. Van Eenaeme ◽  
S. Gauthier ◽  
P. Baldwin ◽  
L. Istasse
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Blood Flow ◽  
Soybean Meal ◽  
Rapid Growth ◽  
Amino Nitrogen ◽  
Vena Cava ◽  
High Growth ◽  
Essential Amino Acids ◽  
Protein Supplementation

The effect of growth rate and protein supplementation on muscle metabolism of eight bulls from the Belgian Blue breed, double-muscled type, was investigated by the arterio-venous difference technique. A low growth (LG) group was maintained at a low growth rate over 36 d, and a rapid growth (RG) group for 28 d before receiving a fattening diet allowing for a rapid growth. At the end of the RG period the RG bulls received a supplement of protected soybean meal. Animals were fitted with an aortic ultrasonic blood flow probe and with catheters in the aorta and the vena cava. The blood flow in the hindlimbs of bulls varied greatly by time of the day but was higher in the RG group. The RG group had a higher arterio-venous difference (AVD) and uptake of alpha-amino nitrogen while AVD in essential amino acids was four times higher and uptake eight times higher. Significant higher AVD or uptake was observed in individual amino acids such as leucine, isoleucine and lysine. The supplementation with protected soybean meal had significant negative effect on the uptake of several amino acids. It was concluded that caution should be exercised when measuring punctually blood flow in muscle tissue, for example by dilution techniques. At high growth rate, the requirements for amino acids are larger than for glucose. Excess protein provides no additional benefit. Key words: Bull, hindlimb catheterism, growth rate, protected soy bean, metabolite

scholarly journals Deciphering the Principles of Bacterial Nitrogen Dietary Preferences: a Strategy for Nutrient Containment

mBio ◽  
2016 ◽  
Vol 7 (4) ◽  
Author(s):  
Jilong Wang ◽  
Dalai Yan ◽  
Ray Dixon ◽  
Yi-Ping Wang
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Growth Rates ◽  
Regulatory Networks ◽  
Metabolic Flux ◽  
Nitrogen Sources ◽  
Fast Growth ◽  
Ammonia Assimilation ◽  
Wild Type ◽  
Dietary Preferences

ABSTRACT A fundamental question in microbial physiology concerns why organisms prefer certain nutrients to others. For example, among different nitrogen sources, ammonium is the preferred nitrogen source, supporting fast growth, whereas alternative nitrogen sources, such as certain amino acids, are considered to be poor nitrogen sources, supporting much slower exponential growth. However, the physiological/regulatory logic behind such nitrogen dietary choices remains elusive. In this study, by engineering Escherichia coli , we switched the dietary preferences toward amino acids, with growth rates equivalent to that of the wild-type strain grown on ammonia. However, when the engineered strain was cultured together with wild-type E. coli , this growth advantage was diminished as a consequence of ammonium leakage from the transport-and-catabolism (TC)-enhanced (TCE) cells, which are preferentially utilized by wild-type bacteria. Our results reveal that the nitrogen regulatory (Ntr) system fine tunes the expression of amino acid transport and catabolism components to match the flux through the ammonia assimilation pathway such that essential nutrients are retained, but, as a consequence, the fast growth rate on amino acids is sacrificed. IMPORTANCE Bacteria exhibit different growth rates under various nutrient conditions. These environmentally related behaviors reflect the coordination between metabolism and the underlying regulatory networks. In the present study, we investigated the intertwined nitrogen metabolic and nitrogen regulatory systems to understand the growth differences between rich and poor nitrogen sources. Although maximal growth rate is considered to be evolutionarily advantageous for bacteria (as remarked by François Jacob, who said that the “dream” of every cell is to become two cells), we showed that negative-feedback loops in the regulatory system inhibit growth rates on amino acids. We demonstrated that in the absence of regulatory feedback, amino acids are capable of supporting fast growth rates, but this results in ammonia leaking out from cells as “waste,” benefiting the growth of competitors. These findings provide important insights into the regulatory logic that controls metabolic flux and ensures nutrient containment but consequently sacrifices growth rate.

scholarly journals Nitrate Promotes Capsaicin Accumulation inCapsicum chinenseImmobilized Placentas

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Jeanny G. Aldana-Iuit ◽  
Enrique Sauri-Duch ◽  
María de Lourdes Miranda-Ham ◽  
Lizbeth A. Castro-Concha ◽  
Luis F. Cuevas-Glory ◽  
...  
Keyword(s):  
Amino Acids ◽  
Structural Damage ◽  
Inorganic Nitrogen ◽  
Placental Tissue ◽  
Nitrogen Sources ◽  
Nitrate Content ◽  
Tissue Sections ◽  
Scanning Electron Microcopy ◽  
Branched Amino Acids

In chili pepper’s pods, placental tissue is responsible for the synthesis of capsaicinoids (CAPs), the compounds behind their typical hot flavor or pungency, which are synthesized from phenylalanine and branched amino acids. Placental tissue sections from Habanero peppers (Capsicum chinenseJacq.) were immobilized in a calcium alginate matrix and culturedin vitro, either continuously for 28 days or during two 14-day subculture periods. Immobilized placental tissue remained viable and metabolically active for up to 21 days, indicating its ability to interact with media components. CAPs contents abruptly decreased during the first 7 days in culture, probably due to structural damage to the placenta as revealed by scanning electron microcopy. CAPs levels remained low throughout the entire culture period, even though a slight recovery was noted in subcultured placentas. However, doubling the medium’s nitrate content (from 40 to 80 mM) resulted in an important increment, reaching values similar to those of intact pod’s placentas. These data suggest that isolated pepper placentas culturedin vitroremain metabolically active and are capable of metabolizing inorganic nitrogen sources, first into amino acids and, then, channeling them to CAP synthesis.

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