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1.
Soil cultures, enrichment cultures, and pure culture isolates produced substantial quantities of salicylic acid from naphthalene in a mineral salts medium containing NH4Cl as the nitrogen source. However, when KNO3 was substituted for NH4Cl, these same cultures failed to accumulate detectable quantities of salicylic acid but did turn the medium yellow. When an isolate identified as a Pseudomonas species was used, viable cell numbers were much greater in the medium containing KNO3, but up to 94% of the naphthalene was utilized in both media. After 48 h of incubation in a 0.1% naphthalene-mineral salts medium, the cultures containing NH4Cl showed irregular clumped cells, a pH of 4.7, 42 μg of salicylic acid per ml, and the production of 4.4 ml of CO2. Under the same conditions, the cultures in the medium containing KNO3 showed uniform cellular morphology, a pH of 7.3, no salicylic acid, the production of 29.7 ml of CO2, and a distinct yellow coloration of the medium. The differences between nitrogen sources could not be accounted for by pH alone since results obtained using buffered media were similar. Growth with NH4NO3 displayed a pattern similar to that obtained when NH4Cl was used. The yellow coloration in the medium containing KNO3 was apparently due to more than one compound, none of which were 1,2-naphthoquinone or acidic in nature, as suggested by other investigators. Further attempts to identify the yellow compounds by high-pressure liquid chromatography, infrared analysis, and gas chromatography-mass spectrometry have been unsuccessful thus far. 相似文献
2.
Sources of Nitrogen Supporting Growth and Embryogenesis in Cultured Wild Carrot Tissue 总被引:5,自引:0,他引:5
This paper seeks to calarify conflicting reports on the nitrogen requirements for in vitro embryogenesis in Daucus carota. Tissue derived from petiole explants of the wild strain of this species were tested with a variety of sources of cellular nitrogen under conditions otherwise favorable for in vitro embryogenesis. The use of very small, sieved and well-washed inocula reduced the carry-over of soluble materials with the inoculum. Embryo yield was quantified by direct counting of samples. Nitrate at concentrations ranging from 5 to 95 mM KNO3 supportes only weak growth and very low embryogenesis under the exacting conditions of these experiments. As little as 0.1 mM NH4Cl added to a nitrate medium allows some embryogenesis and 10 mM NH4Cl is near optimal when KNO3 is in the range of 12 to 40 mM concentration. Glutamine, glutamic acid, urea and alanine can individually partially replace NH4Cl as a supplement to KNO3. Glutamine, alanine, and possibly glutamic acid can serve as sole sources of nitrogen supporting both good growth and embryogenesis. It was concluded that a reduced nitrogen source is required, at least as a supplement to nitrate, for rapid growth and for in vitro embryogenesis of cultured wild carrot tissue. The relationship of pH of the culture medium to growth and embryogenesis was explored and optima observed at approximately pH 5.4 for both processes. 相似文献
3.
The influence of three nitrogen salts: NH4NO3, KNO3 and NH4Cl on wheat in vitro cultures was investigated. Both NO
3
−
and NH
4
+
ions were indispensable for proliferation of embryogenic calli and development of wheat somatic embryos. It is possible to
obtain wheat somatic embryos when the medium is enriched with NH4NO3 only as a source of inorganic nitrogen. The results of the statistical analysis showed that the level of NH4NO3 and KNO3 in the medium had a great influence on the efficiency of somatic embryogenesis. We observed tendency that calli on media
containing 50 mM NH4NO3 and 0 to 20 mM KNO3 turned out to be more embryogenic than on control MS medium. High concentrations of KNO3- 100 mM inhibited somatic embryogenesis, while 100 mM NH4NO3 did not. The level of total N did not have significant influence on wheat somatic embryogenesis. Ratio NO
3
−
:NH
4
+
also turned out to be not substantial. We observed that mutual connection of concentration levels between NH4NO3 and KNO3 and between NH4Cl and KNO3 was more important. The efficiency of somatic embriogenesis obtained in the experiment with NH4Cl and KNO3 was significantly lower than in experiment with NH4NO3 and KNO3. 相似文献
4.
Radish (Raphanus sativus L.) seedlings pretreated with different hormones viz. kinetin, gibberellic acid and abscisic acid were subjected to different
N-forms. The seedlings were treated with different concentrations of KNO3, NH4Cl and NH4NO3 and the changes in nitrate reductase activity were seen in light and dark conditions in the cotyledons. Nitrate reductase
activity was affected differently by hormone application. Nitrate increased and ammonia decreased nitrate reductase activity;
in both light and dark-grown seedlings KNO3 induced more in vitro nitrate reductase activity. NH
4
+
when combined with NO
3
−
, however, could level up to some extent, with KNO3 in light, except in kinetin. A transient response of induction of NR activity was evident with decreased levels after a certain
specific ambient N-concentration, despite the presence of high N in the medium. However, the pattern of transition varied
with the hormones applied. Further, hormones are found to affect induction of different isoforms of nitrate reductase by NH
4
+
and NO
3
−
. NH
4
+
induced isoform was prominently promoted by kinetin treatment in dark. The data documents a particular kind of interaction
between controlling factors (light, N-source and phytohormones) which affect nitrate reductase levels. 相似文献
5.
3T3 and SV-40 transformed 3T3 mouse fibroblasts were cultured in media with serum and antibiotics plus ammonia (NH3 z NH4+) added as NH4C1. Both cell lines cultured without added ammonia showed normal morphology and multiplication even though ammonia in the medium at the end of the culture period ranged from 35 to 48 μg/ml. Ammonia concentrations being significantly higher in media removed from cells at the end of the culture period than in media incubated identically without cells, verified that cells released substantial quantities of ammonia in addition to components of the medium which underwent spontaneous breakdown. Both cell lines showed changes in morphology and highly significant reductions in cell multiplication which increased progressively as the concentration of added ammonia on the initial day of culture was increased to 35μg/ml. Control 3T3 cultures released significantly greater quantities of ammonia per cell than control cultures of transformed cells but their multiplication was more adversely affected by added ammonia. There were downward shifts in pH of the culturing medium for both cell lines as culture age increased at all concentrations of added ammonia, However, significant reductions in cell multiplication resulted from additions of ammonia that did not produce significant changes in extracellular pH. The data show that studies upon the effects of pH of the medium on cultured cells require control of ammonia concentrations. 相似文献
6.
F. Houwaard 《Plant and Soil》1980,54(2):271-282
Summary Addition of ammonium chloride or potassium nitrate to nodulated pea plants resulted in a decrease in acetylene-reducing activity. Both nodule growth and specific activity of the nodules were diminished. Acetylene-reducing activity of isolated bacteroids, treated with EDTA-toluene and supplied with ATP and dithionite, had not decreased after a 3-day treatment of the plants with NH4Cl or KNO3. The effect of combined nitrogen could be counteracted by raising the light intensity or by the addition of sucrose to the growth medium. The latter treatment reduced the nitrogen uptake by the plants. It is concluded that combined nitrogen affects symbiotic nitrogen fixation via the carbohydrate supply to the bacteroids. 相似文献
7.
J. Sahulka 《Biologia Plantarum》1977,19(2):113-128
The effect of some ammonium salts on nitrate reductase (NR) level, onin vivo nitrate reduction and on nitrate content was followed in the presence of nitrate in the medium, under changing experimental conditions, in excisedPisum sativum roots, and their effect was compared with that of KNO3, Ca(NO3)2 and NaNO3 at 15 mM NO3 - concentration, i.e. at a concentration which considerably exceeded the level of saturation with nitrate with respect to nitrate reductase. The effect of ammonium salts on NR level is indirect and changes from a positive one to a strongly negative one which is dependent on the time of action of the salt, on the presence of other cations, on pH of the solution of the ammonium salt and on the nature of the anion of the ammonium salt. A positive effect on the enzyme level can be observed in the presence of other cations than NH4 + at suitable concentrations of those ammonium salts, the solutions of which have their pH values in the acid region (i.e. NH4H2PO4, (NH4)2SO4 and NH4NO3). However their positive effect is independent of the presence of NH4 + ions, and it is obviously the result of an increased concentration of H+ ions. A clear-cut negative effect on NR level can be observed after 24 h in one-salt NH4NO3 solution where NH4 + is not balanced with other cations and thus certainly can adversely influence many metabolic processes, and in the solutions containing neutral (pH 6.2) and dibasic ammonium phosphates in which dissolved undissociated ammonia [(NH3). (H2O) which can also affect many metabolic processes incl. proteosynthesis] probably has a toxic influence. Thein vivo nitrate reduction is always depressed in excised pea roots in the presence of ammonium salts in the medium, regardless of the level of nitrate reductase. Under the described conditions, no relationship could be established between the enzyme level and the so-called metabolic NO3 - pool (i.e. NO2 - production under anaerobic conditions), nor between NR level and the total nitrate content in the roots. One-salt solutions of NaNO3, Ca(NO3)2 and KNO3 exert different effects on the level of nitrate reductase and on the content of NO3 - in the roots, but the in vivo NO3 - reduction shows the same trend as NR level in the roots influenced by these salts. Cl- ions, supplied in NH4C1, depress both NR level and NO3 - content in the roots at higher concentrations, but they do not significantly affect the in vivo nitrate reduction in comparison with other ammonium salts. These results indicate that NR level,in vivo nitrate reduction, and nitrate uptake can be regulated in pea roots independently of each other. 相似文献
8.
Ammonia-induced astrocyte swelling in primary culture 总被引:4,自引:0,他引:4
M. D. Norenberg L. Baker L-O. B. Norenberg J. Blicharska J. H. Bruce-Gregorios J. T. Neary 《Neurochemical research》1991,16(7):833-836
The effect of ammonia on water space of astrocytes in culture was determined as a means of studying the neurotoxicity of ammonia in fulminant hepatic failure (FHF). Treatment of primary astrocyte cultures obtained from neonatal rat cortices with 10 mM NH4Cl for 4 days resulted in a 29% increase in astrocytic water space, as measured by an isotopic method utilizing 3-O-methyl-[3H]-glucose. this effect was time- and dose-dependent. The ammonia-induced swelling was reversible as the water space in cultures treated with 10 mH NH4Cl for 3 days, and then returned to normal culture media for 1 day, was similar to control cultures. These findings suggest that elevated levels of ammonia lead to astrocyte swelling and may contribute to the brain edema in FHF.Special issue dedicated to Dr. Santiago Grisolia 相似文献
9.
N balance and 15N dilution were determined from growth of Azospirillum brasilense Sp7 and two unidentified gram-negative nitrogen-fixing microorganisms in continuous culture supplied with NH4Cl. At the 1.1 and 2.2 mM NH4Cl steady states (N-to-C ratios of 1:68 and 1:34, respectively), the organisms grew with NH4Cl and N2 as N sources simultaneously under carbon limitation. No ammonium could be detected in the supernatant of these cultures. 相似文献
10.
The addition of NH4Cl to Chlorella deprived of CO2, raises the fluorescence yield about 2.5-fold. This effect does not appear to be related to nitrate reduction, and is specific for NH4+. Concentration curves, at varying pH, indicate that the unprotonated ammonia is responsible for this effect. 相似文献
11.
M. H. Abd-Alla 《Folia microbiologica》1994,39(1):53-56
The ability ofRhizobium andBradyrhizobium strains to solubilize phosphate from hydroxyapatite was determined in a medium containing NH4Cl or KNO3. The presence of NH4
+ in the medium resulted in higher solubilization of phosphate as compared to the presence of KNO3, with the exception ofR. leguminosarium bv. viceae strain TAL 1236 and 1402 which solubilized comparable amounts of phosphate in a medium containing either KNO3 or NH4Cl. These results suggest that the strains employ two different mechanisms for phosphate solubilization, one depending on
the presence of NH4
+, the other not requiring its presence. Temperature and aeration (O2 demand) optima were 30°C and 4.2 Hz (shaking frequency), respectively. In nonsterile soil the tested strain (R. meliloti TAL 1236) was very effective in solubilizing rock phosphate. 相似文献
12.
Replacement of potassium ions by ammonium ions in different micro-organisms grown in potassium-limited chemostat culture 总被引:4,自引:0,他引:4
Edward T. Buurman Jill Pennock David W. Tempest M. Joost Teixeira de Mattos Oense M. Neijssel 《Archives of microbiology》1989,152(1):58-63
The biomass concentration extant in potassiumlimited cultures of either Klebsiella pneumoniae or Bacillus stearothermophilus (when growing at a fixed temperature and dilution rate in a glucose/ammonium salts medium) increased progressively as the medium pH value was raised step-wise from 7.0 to 8.5. Because the macromolecular composition of the organisms did not vary significantly, this increase in biomass could not be attributed to an accumulation of storage-type polymers but appeared to reflect a pH-dependent decrease in the cells' minimum K+ requirement. Significantly, this effect of pH was not eviden with cultures in which no ammonium salts were present and in which either glutamate or nitrate was added as the sole nitrogen source; however, it was again manifest when various concentrations of NH4Cl were added to the glutamate-containing medium. This suggested a functional replacement of K+ by NH
4
+
, a proposition consistent with the close similarity of the ionic radii of the potassium ion (1.33 Å) and the ammonium ion (1.43 Å). At pH 8.0, and with a medium containing both glutamate (30 mM) and NH4Cl (100 mM), cultures of B. stearothermophilus would grow without added potassium at a maximum rate of 0.7 h-1. Under these conditions the cells contained maximally 0.1% (w/w) potassium (derived from contaminating amounts of this element in the medium constituents), a value which should be compared with one of 1.4% (w/w) for cells growing in a potassiumlimited medium containing initially 0.5 mM K+. Qualitatively similar findings were made with cultures of K. pneumoniae; and whereas one may not conclude that NH
4
+
can totally replace K+ in the growth of these bacteria, it can clearly do so very extensively. 相似文献
13.
Release and crystallization of berberine in the liquid medium of Thalictrum minus cell suspension cultures 总被引:3,自引:0,他引:3
Cell suspension cultures of Thalictrum minus L. var. hypoleucum Miq. were found to produce a large amount of berberine (400–800 mg/l) when 5–10 M 6-benzyladenine was added to Linsmaier and Skoog's medium containing 100 M 1-naphthaleneacetic acid. Most of the berberine produced was released continuously from the cells into the liquid medium, and an excess of berberine crystallized as its nitrate in the medium. When the cells were cultured in a modified LS medium containing 20 mM KNO3 and 40 mM NH4Cl in place of 20.6 mM NH4NO3 as nitrogen source, most of the alkaloid crystallized to form berberine chloride instead of nitrate. Minor alkaloids, thalifendine and magnoflorine, were also isolated from the medium and identified.Abbreviations LS
Linsmaier and Skoog (1965)
- 2,4-D
2,4-dichlorophenoxyacetic acid
- NAA
1-naphthaleneacetic acid
- BA
6-benzyladenine 相似文献
14.
When grown in vitro in a medium containing NH4NO3 as the sole source of nitrogen, seeds ro the orchid, Cattleya (C. labiata ‘Wonder’ X C. labiata ‘Treasure'), germinated readily and proceeded to form small plantlets. Development of the embryos was accompanied by an increase in their total nitrogen and a decline in the percent dry weight. Growth responses of the seedlings in other ammonium salts like (NH4)2SO4, (NH4)2HPO4, NH4Cl, ammonium acetate and ammonium oxalate were similar to that in NH4NO3. However, when grown in a medium containing NaNO3, development of the seedlings was drastically inhibited; KNO3, Ca(NO3)2, KNO2 and NaNO2 also were poor nitrogen sources. Attempts to grow the seedlings in NaNO3 by changing the pH or by addition of kinetin, molybdenum or ascorbic acid as supplements were completely unsuccessful. When seedlings growing in NH4NO3 for varying periods were transferred to NaNO3, it was found that those plants allowed to grow for 60 or more days in NH4NO3 could resume normal growth thereafter in NaNO3. Determination of the nitrate reductase activity in seedlings of different ages grown in NaNO3, after NH4NO3, showed that the ability of the seedlings to assimilate inorganic nitrogen was paralleled by the appearance of the enzyme. 相似文献
15.
Mature-embryo derived primary calli of the basmati rice (Oryza sativa L.) cv Karnal Local showed significant enhancement in in vitro green-plantlet regeneration efficiency through modification of nitrogen content of the callusing medium. Using KNO3 as the source of nitrate nitrogen and (NH4)2SO4 as the source of ammonium nitrogen, forty-five media combinations involving 9 levels of KNO3 (0–40 mM) and 5 concentrations (0–6.5 mM) of (NH4)2SO4 were examined. The highest frequency of plantlet regeneration (100%) and a maximum number of green-plantlets (~ 7) per embryo-derived primary callus was obtained in calli derived from the medium having 35 mM KNO3 and 5 mM (NH4)2SO4. Higher concentrations of KNO3 and/or (NH4)2SO4 showed a decline in the regeneration efficiency. It was also observed that although the nitrogen content of the callus induction medium had a profound effect on the regenerability of the callus, the nitrogen composition of the regeneration medium also affected it significantly. 相似文献
16.
Bok-Rye Lee Sowbiya Muneer Sang-Hyun Park Qian Zhang Tae-Hwan Kim 《Acta Physiologiae Plantarum》2013,35(9):2655-2664
Excess of ammonia generates oxidative and osmotic stress, and results in an accumulation of compatible solutes. The aim of this study was to investigate the physiological significance of excess ammonium-induced proline and sucrose accumulation on antioxidative activity and osmotic adjustment. The detached leaves of white clover (Trifolium repense L.) were fed with 0, 10, 50, 100, and 200 mM NH4Cl, and the contribution of proline and sucrose to osmotic adjustment and their relationship with antioxidative enzymes activity were assessed. A gradual decline of relative water content and osmotic potential (Ψπ) with increasing NH4Cl feeding level was accompanied by an increase in ammonia concentration. Significant accumulation of proline and sucrose was observed when NH4Cl was fed over 100 mM compared with control (0 mM NH4Cl). The increase in enzyme activity was significant only at 200 mM for ascorbate peroxidase (APOD) and over 100 mM NH4Cl for guaiacol peroxidase (GPOD) and catalase (CAT). The contribution of proline and sucrose to osmotic adjustment over 100 mM, where proline and sucrose accumulation was more important, maintained at control levels or significantly decreased. The content of proline and sucrose as affected by NH4Cl feeding level was positively related with the activity of APOD, GPOD, and CAT. These results suggest that proline and sucrose accumulation induced by the excess of ammonium has a more influential role in antioxidative activity rather than osmotic adjustment. 相似文献
17.
Martínez-Espinosa RM Lledó B Marhuenda-Egea FC Bonete MJ 《Extremophiles : life under extreme conditions》2007,11(6):759-767
Physiology, regulation and biochemical aspects of the nitrogen assimilation are well known in Prokarya or Eukarya but they are poorly described in Archaea domain. The haloarchaeon Haloferax mediterranei can use different nitrogen inorganic sources (NO3−, NO2− or NH4+) for growth. Different approaches were considered to study the effect of NH4+ on nitrogen assimilation in Hfx. mediterranei cells grown in KNO3 medium. The NH4+ addition to KNO3 medium caused a decrease of assimilatory nitrate (Nas) and nitrite reductases (NiR) activities. Similar effects were observed
when nitrate-growing cells were transferred to NH4+ media. Both activities increased when NH4+ was removed from culture, showing that the negative effect of NH4+ on this pathway is reversible. These results suggest that ammonium causes the inhibition of the assimilatory nitrate pathway,
while nitrate exerts a positive effect. This pattern has been confirmed by RT-PCR. In the presence of both NO3− and NH4+, NH4+ was preferentially consumed, but NO3− uptake was not completely inhibited by NH4+ at prolonged time scale. The addition of MSX to NH4+ or NO3− cultures results in an increase of Nas and NiR activities, suggesting that NH4+ assimilation, rather than NH4+ per se, has a negative effect on assimilatory nitrate reduction in Hfx. mediterranei.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
18.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2170-2171
In shaking culture, nitrate reductase activity in the cell-free extracts of Bacillus licheniformis increased with the addition of NH4Cl to the medium containing NaNO3 as a single nitrogen source, where amounts of nitrogen sources were sufficient for cell growth. This increase of nitrate reductase activity therefore suggests that the activity is not for nitrate assimilation but for other physiological functions containing a dissimilatory nitrate reduction. 相似文献
19.
Evolution of O2 by illuminated intact detached leaves from barley (Hordeum vulgare L. cv Athos) and pea (Pisum sativum L. cv Lincoln) in a CO2-saturating atmosphere was enhanced when KNO3 (1-2.5 millimolar) had been previously supplied through the transpiration stream. The extra O2 evolution observed after feeding KNO3 increased with the light intensity, being maximal at near saturating photon flux densities and resulting in no changes in the initial slope of the O2 versus light-intensity curve. No stimulation of O2 evolution was otherwise observed after feeding KCl or NH4Cl. The data indicate that nitrate assimilation uses photosynthetically generated reductant and stimulates the rate of non-cyclic electron flow by acting as a second electron-accepting assimilatory process in addition to CO2 fixation. 相似文献
20.
Andersson AK Adermark L Persson M Westerlund A Olsson T Hansson E 《Neurochemical research》2009,34(3):556-565
Even though ammonia is considered to underlie nervous system symptoms of dysfunction during hyperammonemia, lactate, which
increases as a metabolic consequence of high ammonia levels, might also be a contributing factor. The data presented here
show that NH4Cl (5 mM) mediates astroglial cell swelling, and that treatment with NH4Cl or lactate (25 mM) causes rearrangements of actin filaments and reduces astroglial glutamate uptake capacity. Co-application
with BaCl2, which blocks astroglial uptake of NH4
+, prevents NH4Cl-mediated cell swelling and rearrangement of actin filaments, but does not reduce NH4Cl-induced glutamate uptake capacity inhibition. Neither NH4Cl nor lactate affected glutamate uptake or protein expression in microglial cultures, indicating that astroglial cells are
more susceptible to the neurotoxic affects of ammonia. Our results suggest that ammonium underlies brain edema, but that lactate
can contribute to some of the cellular dysfunctions associated with elevated cerebral levels of ammonia. 相似文献