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1.
Atriplex gmelini plants were regenerated via organogensis from hypocotyl explants. Callus lines were induced from the hypocotyl explants on Linsmaier and Skoog (LS) medium supplemented with 1 M benzyladenine and 5 M -naphthaleneacetic acid in the dark. Shoots were regenerated from the callus lines on LS medium supplemented with 20 M thidiazuron and 0.1 M -naphthaleneacetic acid under a high-intensity light condition (450 mol m–2 s–1). The regenerated shoots were rooted on LS medium without growth regulators to obtain fully developed plants. We succeeded in transforming Atriplex gmelini from callus lines using Agrobacterium tumefaciens. 相似文献
2.
P. S. Meyer J. C. du Preez S. G. Kilian 《World journal of microbiology & biotechnology》1993,9(5):514-520
Mutagenesis of Phaffia rhodozyma with NTG yielded a mutant with an astaxanthin content of 1688 g (g dry biomass)-1, a cell yield coefficient of 0.47 on glucose and a maximum specific growth rate of 0.12 h-1. Re-mutation of the mutant decreased the cell yield and maximum specific growth rate but increased the astaxanthin content. The use of mannitol or succinate as carbon sources enhanced pigmentation, yielding astaxanthin contents of 1973 g g-1 and 1926 g g-1, respectively. The use of valine as sole nitrogen source also increased astaxanthin production, but severely decreased the maximum specific growth rate and cell yield coefficient. The optimum pH for growth of P. rhodozyma was between pH 4.5 and 5.5, whereas the astaxanthin content remained constant above pH 3. 相似文献
3.
(-)-Jasmonic acid was identified as a plant growth inhibitor of the pericarp of Vicia faba by means of gas-liquid chromatography, high resolution mass spectrometry, 1H-nuclear magnetic resonance (1H-NMR), and 13C-NMR. Additionally, the pericarp contains very small amounts of abscisic acid (ABA) and 4-dihydrophaseic acid. The highest level of jasmonic acid was reached prior to full pericarp length. This amount (3 g g-1 fresh weight) is similar to the maximal ABA content in the developing seed. Jasmonic acid is a plant growth inhibitor possessing a relative activity in the wheat seedling bioassay of 1–2.5%, compared to ABA. Contrary to ABA, jasmonic acid does not cause retardation of leaf emergence. The possible physiological role of jasmonic acid in the pericarp is discussed and compared with the assumed function of ABA in developing seeds.Abbreviations ABA
abscisic acid
- DPA
4-dihydrophaseic acid
- DPAMeTMS
methyl ester trimethylsilyl ether of DPA
- EtOAc
ethyl acetate
- Et2O
ether
- MS
mass spectrometry
- NMR
nuclear magnetic resonance
- GLC
gas-liquid chromatography
- TLC
thin-layer chromatography
- UV
ultraviolet light 相似文献
4.
The conserved residue Thr42 of -subunit of the chloroplast ATP synthase of maize (Zea mays L.) was substituted with Cys, Arg, and Ile, respectively, through site-directed mutagenesis. The over-expressed and refolded -proteins were purified by chromatography on DEAE-cellulose and FPLC on mono-Q column, which were as biologically active (inhibiting Ca2+-ATPase activity and blocking proton gate) as the native subunit isolated from chloroplasts. The T42C and T42R showed higher inhibitory activities on the soluble CF1(–) Ca2+-ATPase than the WT. The T42I inhibited the Ca2+-ATPase activity of soluble CF1 and restored photophosphorylation activity of membrane-bound CF1 deficient in the most efficiently. Far-ultraviolet CD spectra showed that the portions of -helix and -sheet structures of the three mutants were somewhat different from WT. Thus the conserved residue Thr42 may be important for maintaining the structure and function of the -subunit and the basic functions of the -subunit as far as an inhibitor of Ca2+-ATPase and the proton gate are related. 相似文献
5.
Paclitaxel production in suspension cell cultures of Taxus 总被引:3,自引:0,他引:3
Five separate cell lines, three of Taxus canadensis Marsh. and two of Taxus cuspidata Sieb. et Zucc., were used to test the effect of carbohydrates and plant growth regulators on the growth of cells and production of paclitaxel in culture. There was no significant correlation between growth of cells and paclitaxel production. While no single medium was developed that was optimal for all cell lines, it was possible to develop a medium for each species that represented a superior combination of growth and paclitaxel production. A combination of NAA and thidiazuron produced the best combination of growth and paclitaxel production in cell lines of T. canadensis, while IAA and BA produced the best results in cell lines of T. cuspidata. A mixture of sucrose and fructose gave the best combination of growth and paclitaxel production. The addition of carbohydrates midway through the growth cycle increased the rate at which paclitaxel accumulated in the culture medium. The highest paclitaxel concentration obtained was 14.78±0.86 mg 1–1 (n=3).Abbreviations 2,4-D
2,4-dichlorophenoxyacetic acid
- 2ip
6-(,-dimethylamino)-purine
- BA
6-benzyladenine
- IAA
indole-3-acetic acid
- IBA
indole-3-butyric acid
- kinetin
6-furfurylaminopurine
- NAA
-napthaleneacetic acid
- picloram
4-amino-3,5,6-trichloropicolinic acid
- thidiazuron
1-phenyl-3 (1,2,3-thiadiazol-5-yl)urea 相似文献
6.
C. J. Liu M. D. Gale 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1989,77(2):233-240
Summary Isoelectric focusing of extracts from the endosperm of mature grains of hexaploid wheat and related species was used to study the genetic control of Iodine binding factor (IBF). Ten IBF bands were present in Chinese Spring (CS) and analysis of the nullisomictetrasomic and ditelosomic lines of CS showed nine of them to be controlled by genes on the long arms of the homoeologous group 5 chromosomes. Five alleles were detected at Ibf-A1 locus, four at Ibf-B1 and four at Ibf-D1 among a sample of 46 wheat genotypes. Homoeoloci were found on chromosome 5R of Secale cereale, 5E of Agropyron elongatum, 5U of Aegilops umbellulata, 5Agi of Agropyron intermedium, 5S1 and 4S1 of Aegilops sharonensis and 4H of Hordeum vulgare. 相似文献
7.
We have studied the mechanism of auxin autonomy in tobacco (Nicotiana tabacum L.) crowngall tissues transformed by the auxin-mutant (tms
–) A66 strain of Agrobacterium tumefaciens. Normally, tms
– tobacco tumor tissues require the formation of shoots to exhibit auxin-independent growth in culture. We have isolated from tms
– tobacco cells several stable variants that are fully hormone-independent and grow rapidly as friable, unorganized tissues, thus mimicking the growth and morphology of tms
+ tobacco cells that produce high levels of auxin. However, none of the variants contained the high levels of auxin found in tms
+ tumor cells. The variants could be divided into two classes with respect to their response to applied auxin. The first class was highly sensitive to applied auxin: low concentrations (1 M) of -naphthaleneacetic acid (NAA) severely inhibited growth and markedly stimulated the accumulation of the ethylene precursor, 1-aminocyclopropane-1-carboxylic acid (ACC). The second class of variants showed a low sensitivity to applied auxin: growth was promoted by concentrations of NAA up to 10 M, and growth inhibition and high ACC levels were observed only at high NAA concentrations (100 M). Unorganized variants with low auxin sensitivity were also isolated from a variant line with high auxin sensitivity. The isolation of tumor cells that exhibited the growth phenotype of tms
+ cells while retaining the low auxin content and low auxin sensitivity of tms
– cells indicates that full hormone autonomy, characteristic of wild-type crown-gall tumors, can be achieved by a mechanism that is independent of changes in the auxin physiology of the cells.Abbreviations ACC
1-aminocyclopropane-1-carboxylic acid
- IAA
indole-3-acetic acid
- MACC
N-malonyl ACC
- NAA
naphthaleneacetic acid
-
tms
tumor morphology shooty, the auxin biosynthesis locus of Agrobacterium Ti plasmids
The authors thank Dr. Andrew Binns (University of Pennsylvania, Philadelphia, USA) for providing cell lines TA6-5 and TA66C3-78, and Mr. James Dacey for preparation of the composite photograph used in Fig. 1. Support for this work by the National Science Foundation (DMB84-17087) and the U.S. Department of Agriculture (86-CRCR-1-2150) is gratefully acknowledged. 相似文献
8.
Kian H. Kwok Parthena Tsoulpha Pauline M. Doran 《Plant Cell, Tissue and Organ Culture》1992,29(2):93-99
The suitability of conductivity measurement for monitoring growth in plant cell culture has been tested using suspended cells and genetically-transformed hairy roots of Atropa belladonna, and aggregated cells of Solanum aviculare. Other researchers have proposed that a constant ratio exists between increase in cell concentration (x) and decrease in medium conductivity (C). In all cases studied in this work, x/C was not constant over a wide range of cell densities tested in batch culture. With cell suspensions, x/C decreased continuously during the growth phase from 3.4 to 2.5 g cm l–1 mS–1. For the hairy roots, the ratio between x and C varied by as much as 4-fold during growth. The relationship between conductivity and growth for S. aviculare aggregates was found to vary depending on inoculum density. No simple correlation between conductivity change and cell growth was apparent for the plant-cell systems studied. 相似文献
9.
The growth and photosynthetic responses ofPterocladiella capillaceato NH4, PO4, CO2-enrichment, pH, irradiance and temperature were evaluated for winter or summer plants cultivated under laboratory and outdoor settings. In the laboratory, using a gradient table, optimal growth temperature and irradiance for winter plants occurred at 10–20 °C and 100 mol photon m–2s–1, averaging 24.3% per week. The optimal growth conditions found for summer plants were 10–20 °C and 20 mol photon m–2s–1, averaging 29.0% per week. In a pH-stat cultivation system photosynthetic rates and growth rates were largely unaffected by pH in the range 6.5–8.5, however, they both decreased significantly above 8.5. In outdoor settings, using 40 L tanks,P. capillaceawas more responsive to the frequency the algae were fed with NH4and PO4rather than the relative concentrations of these nutrients. The average growth rates during winter were 28.3% and 12.5% per week when NH4and PO4were included once and twice a week for 24-h periods, respectively, while summer plants grew 15.0% and 25.3% per week at these nutrient regimes. Algae grown in seawater (containing 13.8 ± 1.8 M CO2) or CO2-enriched seawater (averaging 33.7 ± 13.2 M CO2) had similar growth rates or even reduced productivity under CO2-enrichment during winter. Concentrations of chlorophyllawere in average significantly higher in winter as compared to summer especially when nutrients were included twice a week. Phycoerythrin levels were also higher for plants fed with nutrients twice a week particularly during summer time. Although agar yields were limited and not seasonally dependent, this study shows high growth capacity forP. capillaceaas compared to previous investigations. Future mariculture prospective using current tank cultivation techniques for this species will likely depend on market demands for high quality agar. 相似文献
10.
Copper but not iron limitation increases astaxanthin production by Phaffia rhodozyma in a chemically defined medium 总被引:2,自引:0,他引:2
The influence of copper (0–32 M) and iron (0–108 M) on growth and astaxanthin production by Phaffia rhodozyma was studied. Copper below 3.2 M increased the astaxanthin content of the cells (from 220 to 287 g g–1) but at the expense of a slightly decreased growth (from 11.3 to 10.2 mg ml–1). In contrast, iron below 1 M decreased both the growth and astaxanthin content of the cells. Using copper limitation instead of toxic respiratory inhibitors to improve astaxanthin production has obvious advantages from the product quality, environmental and process operation points of view. 相似文献
11.
The conformational properties of the oligosaccharide chain of GM1 ganglioside containingN-glycolyl-neuraminic acid, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer, were studied through NMR nuclear Overhauser effect investigations on the monomeric ganglioside in dimethylsulfoxide, and on mixed micelles of ganglioside and dodecylphosphocholine in water. Several interresidual contacts for the trisaccharide core--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-were found to fix the relative orientitation of the three saccharides, while the glycosidic linkage of the terminal -Gal-was found to be quite mobile as the -Gal-(1-3)--GalNAc-disaccharide exists in different conformations. These results are similar to those found for two GM1 gangliosides containingN-acetyl-neuraminic acid and neuraminic acid [1].Abbreviations Ganglioside nomenclature is in accordance with Svennerholm [23] and the IUPAC-IUB Recommendations [24] GM3(Neu5Ac)
II3Neu5AcLacCer, -Neu5Ac-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer
- GM3(Neu5Gc)
II3Neu5GcLacCer, -Neu5Gc-(2-3)--Gal-(1-4)--Glc-(1-1)-Cer
- GM1(Neu5Ac)
II3Neu5AcGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer
- GM1(Neu5Gc)
II3Neu5GcGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu5Gc-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer
- GM1(Neu)
II3NeuGgOse4Cer, -Gal-(1-3)--GalNAc-(1-4)-[-Neu-(2-3)]--Glc-(1-1)-Cer
- GD1a
IV3Neu5AcII3Neu5AcGgOse4Cer, -Neu5Ac-(2-3)--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer
- GalNAc-GD1a
IV4GalNAcIV3Neu5AcII3Neu5AcGgOse4Cer, -GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-3)--GalNAc-(1-4)-[-Neu5Ac-(2-3)]--Gal-(1-4)--Glc-(1-1)-Cer
- Neu
neuraminic acid
- Neu5Ac
N-acetyl-neuraminic acid
- Neu5Gc
N-glycolyl-neuraminic acid
- Cer
ceramide 相似文献
12.
Christine L. Truitt Elizabeth A. Weaver William G. Haldenwang 《Molecular & general genetics : MGG》1988,212(1):166-171
Summary The E-37 gene ctc was inactivated by a site-specific insertion into the Bacillus subtilis chromosome. The resulting mutation inhibited sporulation by 95% at elevated temperatures (48° C). If the ctc
- mutation is placed in a strain that carries a mutation in the closely linked but distinct spoVC gene, ctc now affects both growth and sporulation at elevated temperatures. Growth of the ctc
- spoVC285 strain was transiently inhibited when exponentially growing cultures were shifted from 37° C to 48° C. A similar, but less pronounced growth lag, was also seen in a B. subtilis strain carrying only the spoVC-285 mutation. This finding suggests that both the ctc and spoVC products function in vegetatively growing B. subtilis. 相似文献
13.
Alf Gunnarsson 《Glycoconjugate journal》1987,4(3):239-245
O-Methylation of simple neutral oligosaccharides is readily accomplished in dimethyl sulphoxide containing solid sodium hydroxide and methyl iodide [Cincanu I, Kerek F (1984) Carbohydr Res 131209-17]. This procedure has been extended to 2-acetamido-2-deoxy sugars and sialic acid-containing oligosaccharides. CompleteO-andN-methylation was in most cases achieved in 15 min. Esterification of carboxylic groups in uronic acids was fast and resulted in concomitant -elimination. The method is also suitable for methylation of glycoproteins and glycosphingolipids. Polysaccharides can also be methylated by this technique. Analysis of the products by gas-liquid chromatography and mass spectrometry showed no degradation products.Abbreviations lacto-N-tetraose
LcOse4, Gal3GlcNAc3Gal4Glc
- lacto-N-fucopentaose III
III3Fuc-nLcOse4, Gal4[Fuc3]GlcNAc3Gal4Glc
- trihexosylceramide
GbOse3Cer, Gal4Gal4Glc1-1Cer
- globoside
GbOse4Cer, GalNAc3Gal4Glc1-1Cer
- FAB-MS
fas atom bombardment mass spectrometry 相似文献
14.
The cytokinin activities of cis and trans ribosylzeatin isomers and that of N6-(2-isopentenyl)adenosine were compared in four bioassays. The trans isomer was found to be more active than the cis isomer in stimulation of cucumber cotyledon expansion (100x), retention of chlorophyll in detached leaf pieces (7x), induction and stimulation of chlorophyll synthesis in cucumber cotyledons (20x) and of betacyanin synthesis in Amaranthus caudatus seedlings grown in the dark (60x). The N6-(2-isopentenyl)adenosine adenosine was less active than the trans ribosylzeatin in all four bioassays and more active than the cis ribosylzeatin in induction and stimulation of betacyanin and chlorophyll synthesis. These results show that the hydroxylation of the trans methyl group in the N6 side chain of N6-(2-isopentenyl)adenosine increases the biological activity and that this activity is either decreased or not significantly changed when the cis methyl group is hydroxylated.Abbreviations i6Ado
N6-(2-isopentenyl)adenosine or 6-(3-methyl-2-butenylamino)-9--D-ribofuranosylpurine
- t-to6Ado
trans-ribosylzeatin or 6-(4-hydroxy-3-methyl-trans-2-butenylamino)-9--D-ribofuranosylpurine
- c-io6Ado
cis-ribosylzeatin or 6-(4-hydroxy-3-methyl-cis-2-butenylamino)-9--D-ribofuranosylpurine
- HPLC
high pressure liquid chromatography 相似文献
15.
Masa-aki Okuyama Yoshihiro Kobayashi Masahiro Inouhe Hiroshi Tohoyama Masanori Joho 《Biometals》1999,12(4):307-314
Copper-induced metallothionein (MT) synthesis in Saccharomyces cerevisiae was investigated in order to associate this exclusively with Cu2+
in vivo, when cultured in nutrient medium containing other heavy metal ions. Expression of the CUP1 promoter/lacZ fusion gene was inhibited by all heavy metal ions tested, especially Cd2+ and Mn2+. By adding Cd2+ and Mn2+ at 10 M concentration, the -galactosidase activity decreased by about 80% and 50% of the maximum induction observed with 1 mM CuSO4, respectively. Furthermore, cell growth was markedly inhibited by combinations of 1 mM-Cu2+ and 1 M-Cd2+. Therefore, the yeast S. cerevisiae could not rely on MT synthesis as one of the copper-resistance mechanisms, when grown in a Cd2+ environment. In contrast, the presence of Mn2+ in the nutrient medium showed alleviation rather than growth inhibition by high concentrations of Cu2+. The recovery from growth inhibition by Mn2+ was due to decreased Cu2+ accumulation. Inhibitory concentrations of Co2+, Ni2+ and Zn2+ on expression of the CUP1p/lacZ fusion gene were at least one order of magnitude higher than that of Cd2+ and Mn2+. These results are discussed in relation to Cu2+ transport and Cu-induced MT synthesis in the copper-resistance mechanism of the yeast S. cerevisiae. 相似文献
16.
Indole-3-acetic acid (IAA), fusicoccin and weak acids all lower the cytoplasmic pH (pHi) and induce elongation growth of maize (Zea mays L.) coleoptiles. Gibberellic acid (GA3) also induces elongation growth and we have used confocal laser scanning microscopy to study the effects of GA3 on pHi employing the pH-indicator dyes, 2,7-bis(2-carboxyethyl)-5-(and-6) carboxyfluorescein and carboxy-semi-naphthorhodafluor-1. We confirm that GA3 induces growth significantly in light-grown but only slightly or not at all in dark-grown coleoptiles. The growth induced by IAA treatment was similar in light- and dark-grown coleoptiles. The pHi decreased by up to 0.6 units during the first 7 min of GA3 or IAA treatment of both light- and dark-grown coleoptiles. Gibberellic acid inhibited IAA-induced growth of dark-grown coleoptiles. Hence, in dark-grown coleoptiles GA3 may activate either directly or indirectly reactions that interfere with the signalling pathway leading to elongation growth. The possible role of pHi in growth is discussed.Abbreviations ABA
abscisic acid
- AM
acetoxymethyl ester
- BCECF
2,7-bis(2-carboxyethyl)-5-(and-6) carboxyfluorescein
- [Ca2+]i
cytoplasmic free calcium
- GA(n)
gibberellin A(n)
- GA3
gibberellic acid
- IAA
indole-3-acetic acid
- PGR
plant growth regulator
- pHi
cytoplasmic pH
- Pipes
piperazine-N,N-bis[2-ethanesulfonic acid]
- Snarf-1
carboxy-semi-naphthorhodafluor-1
We thank Dr R. King (CSIRO, Canberra) for providing the GA1 and T. Phillips for processing the photographic material. H.R. Irving was supported by an Australian Research Council Research Fellowship and the work was supported by an Australian Research Council grant. 相似文献
17.
Photosynthetic rates and related anatomical characteristics of leaves developed at three levels of irradiance (1200, 300 and 80 umol · m–2 · s–1) were determined in the C4-like species Flaveria brownii A.M. Powell, the C3–C4-intermediate species F. linearis Lag., and the F1 hybrid between them (F. brownii × F. linearis). In the C3–C4 and F1 plants, increases in photosynthetic capacity per unit leaf area were strongly correlated with changes in mesophyll area per unit leaf area. The C4-like plant F. brownii, however, showed a much lower correlation between photosynthetic capacity and mesophyll area per unit leaf area. Plants of F. brownii developed at high irradiance showed photosynthetic rates per unit of mesophyll cell area 50% higher than those plants developed at medium irradiance. These results along with an increase in water-use efficiency are consistent with an increase of C4 photosynthesis in high-irradiance-grown F. brownii plants, whereas in the other two genotypes such plasticity seems to be absent. Photosynthetic discrimination against 13C in the three genotypes was less at high than at low irradiance, with the greatest change occurring in F. brownii. Discrimination against 13C expressed as
13C was linearly correlated (r
2 = 0.81; P<0.001) with the ratio of bundle-sheath volume to mesophyll cell area when all samples from the three genotypes were combined. This tissue ratio increased for F. brownii and the F1 hybrid as growth irradiance increased, indicating a greater tendency towards Kranz anatomy. The results indicated that F. brownii had plasticity in its C4-related anatomical and physiological characteristics as a function of growth irradiance, whereas plasticity was less evident in the F1 hybrid and absent in F. linearis.Abbreviations A
leaf surface area
- Ama, Amn, Alm
total ma, mn or lm cell surface area
- bs
vascular bundle sheath
- lm
large spongy-mesophyll cells
- ma
mesophyll cells adjacent to bundle sheath
- mn
mesophyll cells not adjacent to bundle sheath
- Pn
net photosynthesis
- (H, M, L) PPFD
(high, medium, low) photosynthetic photon flux density
- SLDW
specific leaf dry wight
- Vbs
bs volume
- V(ma + mn + bs)
total photosynthetic tissue volume
- 13C
13C discrimination
We thank Mrs. Lisa Smith for technical assistance in light microscopy and Dr. Ned Friedman (Department of Botany, University of Georgia, Athens, GA, USA) for the use of digitizing equipment. Participation of Dr. J.L. Araus in this work was supported by a grant Beca de Especialización para Doctores y Tecnólogos en el Extranjero, from Ministerio de Educatión y Ciencia, Spain. 相似文献
18.
The growth of mustard was increased significantly when treated with up to 80 kg N ha–1 (N80). Spraying with (2-chloroethyl) trimethylammoniumchloride (chlormequat chloride) increased seed yield and seed protein content. Spraying nitrogen fertilized plots with chlormequat chloride, increased leaf area, leaf area ratio, leaf area duration, number of siliquae plant–1, number of seeds siliqua–1 and length of siliqua. Reducing, non-reducing and total sugars in the leaves at 80 days after sowing were also affected significantly. Chlorophyll a, b and total chlorophyll were little affected. The number of siliquae plant–1 was highly correlated with seed yield in both the seasons of experimentation. The correlation coefficient value () was 0.586 in 1982/83 and 0.912 in 1983/84.The total accumulation of nutrients, i.e. nitrogen, phosphorus and potassium in seed and straw was significantly affected by N80 × chlormequat chloride interaction. 相似文献
19.
Uptake of 35S-labelled sulfate and thiosulfate was studied in twenty sulfate-reducing bacteria. Micromolar additions of these substrates were highly accumulated by washed cells of freshwater and marine strains. In marine strains accumulation required Na+. Generally, the uptake capacity was increased after sulfate limitation during growth. With two marine species, Desulfovibrio salexigens and Desulfobacterium autotrophicum, the effects of various ionophores and inhibitors affecting the transmembrane pH or Na+ gradient or the membrane potential were studied. In both strains transport was reversible. There was no discrimination between sulfate and thiosulfate. With increasing additions the amount taken up increased, while the accumulation factor (Cin/Cout) decreased. Uptake was not directly correlated with the ATP level inside the cells. From these results and the action patterns of the inhibitors tested it is concluded that marine sulfate-reducing bacteria accumulate sulfate and thiosulfate electrogenically in symport with Na+ ions, while in freshwater strains protons are symported. The high-accumulating systems are induced only at low sulfate concentration, while low-accumulating systems are active at sulfate-sufficient conditions.Abbreviations CCCP
carbonyl cyanide m-chlorophenylhydrazone
- DCCD
dicyclohexylcarbodiimide
- ETH 157
N, N-dibenzyl-N,N-diphenyl-1,2-diphenylendioxydiacetamide
- TCS
3,3,4,5-tetrachlorosalicylanilide 相似文献
20.
Ammonia reversibly inhibits the nitrogenase activity not only in purple nonsulfur bacteria but in purple (Thiocapsa roseopersicina) and green (Chlorobium limicola forma thiosulfatophilum) sulfur bacteria as well.The complete inhibition of nitrogenase activity (acetylene reduction) is observed about 30 s after addition of NH
4
+
(2.5×10-6 M) to cell suspensions. The pattern of ammonia inhibition of acetylene reduction in T. roseopersicina does not differ from the action of tetrabutylammonium and tetraphenylphosphonium (3 · 10-6-5·10-5 M) on nitrogenase activity of this bacterium.Simultaneously with the switch-off effect of NH
4
+
a considerable increase of ATP in cells of Rhodobacter sphaeroides and C. limicola f. thiosulphatophilum was observed. 相似文献